Evaluating hyperspectral imaging of wetland vegetation as a tool for detecting estuarine nutrient enrichment

Nutrient enrichment and eutrophication are major concerns in many estuarine and wetland ecosystems, and the need is urgent for fast, efficient, and synoptic ways to detect and monitor nutrients in wetlands and other coastal systems across multiple spatial and temporal scales. We integrated three approaches in a multi-disciplinary evaluation of the potential for using hyperspectral imaging as a tool to assess nutrient enrichment and vegetation responses in tidal wetlands. For hyperspectral imaging to be an effective tool, spectral signatures must vary in ways correlated with water nutrient content either directly, or indirectly via such proxies as vegetation responses to elevated nitrogen. Working in Elkhorn Slough, central California, where intensive farming practices generate considerable runoff of fertilizers and pesticides, we looked first for long- and short-term trends among temporally ephemeral point data for nutrients and other water quality characters collected monthly at 18 water sampling stations since 1988. Second, we assessed responses of the dominant wetland plant, Salicornia virginica (common pickleweed) to two fertilizer regimes in 0.25 m² experimental plots, and measured changes in tissue composition (C, H, N), biomass, and spectral responses at leaf and at canopy scales. Third, we used HyMap hyperspectral imagery (126 bands; 15–19 nm spectral resolution; 2.5 m spatial resolution) for a synoptic assessment of the entire wetland ecosystem of Elkhorn Slough. We mapped monospecific Salicornia patches (～ 56–500 m²) on the ground adjacent to the 18 regular water sampling sites, and then located these patches in the hyperspectral imagery to correlate long-term responses of larger patches to water nutrient regimes. These were used as standards for correlating plant canopy spectral responses with nitrogen variation described by the water sampling program. There were consistent positive relationships between nitrogen levels and plant responses in both the field experiment and the landscape analyses. Two spectral indices, the Photochemical Reflectance Index (PRI) and Derivative Chlorophyll Index (DCI), were correlated significantly with water nutrients. We conclude that hyperspectral imagery can be used to detect nutrient enrichment across three spatial and at least two temporal scales, and suggest that more quantitative information could be extracted with further research and a greater understanding of physiological and physical mechanisms linking water chemistry, plant properties and spectral imaging characteristics.     

Fibrous carbon materials having a protective oxidation resistant coating

Conclusions -- A gas-phase method of depositing one- or multiple-component carbide coatings on CFM of various textile structures has been developed. With preservation of the strength and elastic characteristics of the CFM, the thermo-oxidative resistance of the material is increased, plus the temperature range for the decomposition is shifted into the higher temperature region — by 150–250°C as compared with the starting material.-- CFM with protective coatings are finding ever greater use in making filters for cleaning up high-temperature gas-air mixtures.VNIIPV. Translated from Khimicheskie Volokna, No. 3, pp. 47–48, May–June, 1991.     

Modification of the surface of polyacrylonitrile fibres before oxidation with a dispersion of technical carbon

Conclusions -- The possibility of using dispersions of technical carbon in a medium of ethylene glycol, an aqueous solution of a binder of the Sokrat-binder type, or an alcoholic solution of polyvinyl butyral for the modification of polyacrylonitrile fibres before thermo-oxidation, which ensure obtaining a stable and uniform carbon-containing film on the fibre surface has been established.-- The use of ethylene glycol as the dispersion medium leads to retention of the strength of fibres after heat treatment at the level of the starting fibres and reduces the specific bulk electrical resistance.-- Application of aqueous solutions of the Sokrat-binder aids in preserving fibre strength during thermo-oxidation. The linear density of the fibre and its ability to be oxidized are increased, but the specific bulk electrical resistance and elongation are reduced.-- The use of alcoholic solutions of polyvinyl butyral makes it possible not only to preserve fibre strength but also to considerably increase it during the thermo-oxidation process. Thereupon, the linear density of the fibres is significantly reduced, and at a dispersion content of 10% by wt. technical carbon, one can obtain electrically-conducting oxidized fibres.Translated from Khimicheskie Volokna, No. 4, pp. 36–37, July–August, 1991.     

The “Angiogenic Switch” and Functional Resources in Cyclic Sports Athletes

Regular physical activity in cyclic sports can influence the so-called “angiogenic switch”, which is considered as an imbalance between proangiogenic and anti-angiogenic molecules. Disruption of the synthesis of angiogenic molecules can be caused by local changes in tissues under the influence of excessive physical exertion and its consequences, such as chronic oxidative stress and associated hypoxia, metabolic acidosis, sports injuries, etc. A review of publications on signaling pathways that activate and inhibit angiogenesis in skeletal muscles, myocardium, lung, and nervous tissue under the influence of intense physical activity in cyclic sports. Materials: We searched PubMed, SCOPUS, Web of Science, Google Scholar, Clinical keys, and e-LIBRARY databases for full-text articles published from 2000 to 2020, using keywords and their combinations. Results: An important aspect of adaptation to training loads in cyclic sports is an increase in the number of capillaries in muscle fibers, which improves the metabolism of skeletal muscles and myocardium, as well as nervous and lung tissue. Recent studies have shown that myocardial endothelial cells not only respond to hemodynamic forces and paracrine signals from neighboring cells, but also take an active part in heart remodeling processes, stimulating the growth and contractility of cardiomyocytes or the production of extracellular matrix proteins in myofibroblasts. As myocardial vascularization plays a central role in the transition from adaptive heart hypertrophy to heart failure, further study of the signaling mechanisms involved in the regulation of angiogenesis in the myocardium is important in sports practice. The study of the “angiogenic switch” problem in the cerebrovascular and cardiovascular systems allows us to claim that the formation of new vessels is mediated by a complex interaction of all growth factors. Although the lungs are one of the limiting systems of the body in cyclic sports, their response to high-intensity loads and other environmental stresses is often overlooked. Airway epithelial cells are the predominant source of several growth factors throughout lung organogenesis and appear to be critical for normal alveolarization, rapid alveolar proliferation, and normal vascular development. There are many controversial questions about the role of growth factors in the physiology and pathology of the lungs. The presented review has demonstrated that when doing sports, it is necessary to give a careful consideration to the possible positive and negative effects of growth factors on muscles, myocardium, lung tissue, and brain. Primarily, the “angiogenic switch” is important in aerobic sports (long distance running). Conclusions: Angiogenesis is a physiological process of the formation of new blood capillaries, which play an important role in the functioning of skeletal muscles, myocardium, lung, and nervous tissue in athletes. Violation of the “angiogenic switch” as a balance between proangiogenic and anti-angiogenic molecules can lead to a decrease in the functional resources of the nervous, musculoskeletal, cardiovascular, and respiratory systems in athletes and, as a consequence, to a decrease in sports performance.     

Molecular Mechanisms of the Deregulation of Muscle Contraction Induced by the R90P Mutation in Tpm3.12 and the Weakening of This Effect by BDM and W7

Point mutations in the genes encoding the skeletal muscle isoforms of tropomyosin can cause a range of muscle diseases. The amino acid substitution of Arg for Pro residue in the 90th position (R90P) in γ-tropomyosin (Tpm3.12) is associated with congenital fiber type disproportion and muscle weakness. The molecular mechanisms underlying muscle dysfunction in this disease remain unclear. Here, we observed that this mutation causes an abnormally high Ca²⁺-sensitivity of myofilaments in vitro and in muscle fibers. To determine the critical conformational changes that myosin, actin, and tropomyosin undergo during the ATPase cycle and the alterations in these changes caused by R90P replacement in Tpm3.12, we used polarized fluorimetry. It was shown that the R90P mutation inhibits the ability of tropomyosin to shift towards the outer domains of actin, which is accompanied by the almost complete depression of troponin’s ability to switch actin monomers off and to reduce the amount of the myosin heads weakly bound to F-actin at a low Ca²⁺. These changes in the behavior of tropomyosin and the troponin–tropomyosin complex, as well as in the balance of strongly and weakly bound myosin heads in the ATPase cycle may underlie the occurrence of both abnormally high Ca²⁺-sensitivity and muscle weakness. BDM, an inhibitor of myosin ATPase activity, and W7, a troponin C antagonist, restore the ability of tropomyosin for Ca²⁺-dependent movement and the ability of the troponin–tropomyosin complex to switch actin monomers off, demonstrating a weakening of the damaging effect of the R90P mutation on muscle contractility.     

Experimental methods in chemical engineering: X‐ray photoelectron spectroscopy‐XPS

X‐ray photoelectron spectroscopy (XPS) is a quantitative surface analysis technique used to identify the elemental composition, empirical formula, chemical state, and electronic state of an element. The kinetic energy of the electrons escaping from the material surface irradiated by an x‐ray beam produces a spectrum. XPS identifies chemical species and quantifies their content and the interactions between surface species. It is minimally destructive and is sensitive to a depth between 1–10nm. The elemental sensitivity is in the order of 0.1 atomic %. It requires ultra high vacuum ( Pa) in the analysis chamber and measurement time varies from minutes to hours per sample depending on the analyte. XPS dates back 50 years ago. New spectrometers, detectors, and variable size photon beams, reduce analysis time and increase spatial resolution. An XPS bibliometric map of the 10 000 articles indexed by Web of Science^[1] identifies five research clusters: (i) nanoparticles, thin films, and surfaces; (ii) catalysis, oxidation, reduction, stability, and oxides; (iii) nanocomposites, graphene, graphite, and electro‐chemistry; (iv) photocatalysis, water, visible light, and ; and (v) adsorption, aqueous solutions, and waste water.     

Order picking system design: the storage assignment and travel distance estimation (SA&TDE) joint method

Of all the warehouse activities, order picking is one of the most time-consuming and expensive. In order to improve the task, several researches have pointed out the need to consider jointly the layout of the warehouse, the storage assignment strategy and the routing policy to reduce travelled distances and picking time. This paper presents the storage assignment and travel distance estimation (SA&TDE) joint method, a new approach useful to design and evaluate a manual picker-to-parts picking system, focusing on goods allocation and distances estimation. Starting from a set of picking orders received in a certain time range, this approach allows to evaluate the combinations of product codes assigned to storage locations, aisles, sections or warehouse areas and to assess the most relevant ones, for the best location and warehouse layout, with the aim of ensuring optimal picking routes, through the application of the multinomial probability distribution. A case study is developed as well, in order to clarify the concept that underlies the SA&TDE joint method, and to show the validity and the flexibility of the approach, through the calculation of the saving at different levels of detail.