Conserving land, protecting water

Water resource management / Water productivity / Water conservation / Recycling / Land management / Soil conservation / Ecosystems / Ecology / Evapotranspiration / Food security / Poverty / River basins / Irrigated farming

Three protected tetrapeptides

The structures of three protected tetrapeptides, containing the Boc-Gly-Gly-Phe-X-OMe chain, tert-butoxycarbonyl-glycy-glycl-phenylalanine-leucine methyl ester dihydrate, Boc-Gly-Gly-L-Phe-D-Leu-OMe, C25H38N4O7·2H2O, tert-butoxycarbonyl-glycy-glycl-phenylalanine-methionine methyl ester dihydrate, Boc-Gly Gly-L-Phe-D-Met-OMe, C24H36N4O7S.2H2O and tert-butoxycarbonyl-glycy-glycl-phenylalanine-norleucine methyl ester dihydrate, Boc-Gly-Gly-D-Phe-L-Nle-OMe, C25H38N4O7.2H2O, are described. The three molecules have the same conformation of the Boc-Gly Gly Phe-X-OMe tetrapeptide chain and display the same packing, consisting of couples of molecules linked head-to-tail by two hydrogen (N-HO) bonds; other hydrogen bonds, also involving two water molecules of crystallization, link these couples together, and give rise to a planar structure

Symmetry-Protected Topological Entanglement

We propose an order parameter for the Symmetry-Protected Topological (SPT) phases which are protected by Abelian on-site symmetries. This order parameter, called the "SPT-entanglement", is defined as the entanglement between A and B, two distant regions of the system, given that the total charge (associated with the symmetry) in a third region C is measured and known, where C is a connected region surrounded by A, B and the boundaries of the system. In the case of 1-dimensional systems we prove that in the limit where A and B are large and far from each other compared to the correlation length, the SPT-entanglement remains constant throughout a SPT phase, and furthermore, it is zero for the trivial phase while it is nonzero for all the non-trivial phases. Moreover, we show that the SPT-entanglement is invariant under the low-depth quantum circuits which respect the symmetry, and hence it remains constant throughout a SPT phase in the higher dimensions as well. Also, we show that there is an intriguing connection between SPT-entanglement and the Fourier transform of the string order parameters, which are the traditional tool for detecting SPT phases. This leads to a new algorithm for extracting the relevant information about the SPT phase of the system from the string order parameters. Finally, we discuss implications of our results in the context of measurement-based quantum computation.Comment: V4: close to the published version. V3: The paper is rewritten (24 pages, 8 Figures). Several new sections are added to the paper: (i) An example about (perturbed) cluster Hamiltonian, (ii) A discussion on the implications of our results in the context of measurement-based quantum computation. (iii) A preliminary section reviewing basic concepts (Entanglement, symmetry, SPT order). in PRB (2017

Universal symmetry-protected topological invariants for symmetry-protected topological states

Symmetry-protected topological (SPT) states are short-range entangled states with a symmetry G. They belong to a new class of quantum states of matter which are classified by the group cohomology $H^{d+1}(G,\mathbb{R}/\mathbb{Z})$ in d-dimensional space. In this paper, we propose a class of symmetry- protected topological invariants that may allow us to fully characterize SPT states with a symmetry group G (ie allow us to measure the cocycles in $H^{d+1}(G,\mathbb{R}/\mathbb{Z})$ that characterize the SPT states). We give an explicit and detailed construction of symmetry-protected topological invariants for 2+1D SPT states. Such a construction can be directly generalized to other dimensions.Comment: 12 pages, 11 figures. Added reference

Toll v. Dist. Ct. (Gilman), 135 Nev., Advanced Opinion 58 (December 5, 2019)

A blogger claimed that his sources are protected under NRS 49.275. The court held that digital media is protected, but did not address whether a blogger is protected. The district court did not err in allowing discovery to determine whether the blogger acted with actual malice

A note on the UV behaviour of maximally supersymmetric Yang-Mills theories

The question of whether BPS invariants are protected in maximally supersymmetric Yang-Mills theories is investigated from the point of view of algebraic renormalisation theory. The protected invariants are those whose cohomology type differs from that of the action. It is confirmed that one-half BPS invariants ($F^4$) are indeed protected while the double-trace one-quarter BPS invariant ($d^2F^4$) is not protected at two loops in D=7, but is protected at three loops in D=6 in agreement with recent calculations. Non-BPS invariants, i.e. full superspace integrals, are also shown to be unprotected.Comment: 12 pages. Minor changes to text. References adde

From the Galalpagos to Tongariro: Recognizing and saving the most important places in the world

Protected areas are one of the less glamorous areas of international environmental law. They are commonly overshadowed by what are perceived as much more dramatic topics, which capture the public attention to a much greater degree.1 This is a highly ironic situation for three reasons. First, because protected areas are the foremost methods by which species and ecosystems are effectively preserved. Second, because protected areas are tangible, and are not merely theoretical constructs. Third, the obligation to create protected areas is one of the most long-standing goals in numerous environmental treaties. For a long time this goal was not tied to any specific outcomes, and the numbers of protected areas grew slowly. However, in the new century, due to an increased recognition of the above considerations, the international community has not only reiterated the goal to create more protected areas, they also set targets of what they want to achieve. The international interest is this area can be seen with a number of examples, such as marine protected areas and transboundary protected areas. Collectively, such support has lead to the creation, in total, of over 102,000 protected areas spread over the Earth

In Vivo Renal Clearance, Biodistribution, Toxicity of Gold nanoclusters

Gold nanoparticles have shown great prospective in cancer diagnosis and therapy, but they can not be metabolized and prefer to accumulate in liver and spleen due to their large size. The gold nanoclusters with small size can penetrate kidney tissue and have promise to decrease in vivo toxicity by renal clearance. In this work, we explore the in vivo renal clearance, biodistribution, and toxicity responses of the BSA- and GSH-protected gold nanoclusters for 24 hours and 28 days. The BSA-protected gold nanoclusters have low-efficient renal clearance and only 1% of gold can be cleared, but the GSH-protected gold nanoclusters have high-efficient renal clearance and 36 % of gold can be cleared after 24 hours. The biodistribution further reveals that 94% of gold can be metabolized for the GSH-protected nanoclusters, but only less than 5% of gold can be metabolized for the BSA-protected nanoclusters after 28 days. Both of the GSH- and BSA-protected gold nanoclusters cause acute infection, inflammation, and kidney function damage after 24 hours, but these toxicity responses for the GSH-protected gold nanoclusters can be eliminated after 28 days. Immune system can also be affected by the two kinds of gold nanoclusters, but the immune response for the GSH-protected gold nanoclusters can also be recovered after 28 days. These findings show that the GSH-protected gold nanoclusters have small size and can be metabolized by renal clearance and thus the toxicity can be significantly decreased. The BSA- protected gold nanoclusters, however, can form large compounds and further accumulate in liver and spleen which can cause irreparable toxicity response. Therefore, the GSH-protected gold nanoclusters have great potential for in vivo imaging and therapy, and the BSA-protected gold nanoclusters can be used as the agent of liver cancer therapy.Comment: 12 pages, 8 figure

Synthesis of biodegradable polyesteramides with pendant functional groups

Morpholine-2,5-dione derivatives having substituents with benzyl-protected carboxylic acid, benzyloxycarbonyl-protected amine and p-methoxy-protected thiol groups, respectively, were prepared in 29-58% yield by cyclization of the corresponding N-[(2RS)-bromopropionyl]-L-amino acids. Polyesteramides with protected pendant functional groups were obtained by ring-opening copolymerization of either ε-caprolactone or DL-lactide with morpholine-2,5-dione derivatives having protected functional substituents. The copolymerizations were carried out in the bulk at 130°C using stannous octoate as an initiator and using low mole fractions (0,05, 0,10 and 0,20) of morpholine-2,5-dione derivatives in the feed. The molecular weight of the resulting copolymers ranged from 1,4 to 8,3 · 104. The ring-opening homopolymerization of morpho-line-2,5-dione derivatives with protected functional substituents was not successful. Polyesteramides with either pendant carboxylic acid groups or pendant amine groups were prepared by catalytic hydrogenation of the corresponding protected copolymers. Treatment of copolymers having pendant p-methoxybenzyl-protected thiol groups with trifluoromethanesulfonic acid resulted not only in the removal of the p-methoxybenzyl group but also in severe degradation of the copolymers, due to acidolysis of main-chain ester bonds