Remotely sensed mid-channel bar dynamics in downstream of the Three Gorges Dam, China

The downstream reach of the Three Gorges Dam (TGD) along the Yangtze River (1560 km) hosts numerous mid-channel bars (MCBs). MCBs dynamics are crucial to the river’s hydrological processes and local ecological function. However, a systematic understanding of such dynamics and their linkage to TGD remains largely unknown. Using Landsat-image-extracted MCBs and several spatial-temporal analysis methods, this study presents a comprehensive understanding of MCB dynamics in terms of number, area, and shape, over downstream of TGD during the period 1985−2018. On average, a total of 140 MCBs were detected and grouped into four types representing small ( 2 km2), middle (2 km2 − 7 km2), large (7 km2 − 33 km2) and extra-large size (>33 km2) MCBs, respectively. MCBs number decreased after TGD closure but most of these happened in the lower reach. The area of total MCBs experienced an increasing trend (2.77 km2/yr, p-value 0.01) over the last three decades. The extra-large MCBs gained the largest area increasing rate than the other sizes of MCBs. Small MCBs tended to become relatively round, whereas the others became elongate in shape after TGD operation. Impacts of TGD operation generally diminished in the longitudinal direction from TGD to Hankou and from TGD to Jiujiang for shape and area dynamics, respectively. The quantified longitudinal and temporal dynamics of MCBs across the entire Yangtze River downstream of TGD provides a crucial monitoring basis for continuous investigation of the changing mechanisms affecting the morphology of the Yangtze River system

Helicity Dependent Directional Surface Plasmon Polariton Excitation Using A Metasurface with Interfacial Phase Discontinuity

Surface plasmon polaritons (SPPs) have been widely exploited in various scientific communities, ranging from physics, chemistry to biology, due to the strong confinement of light to the metal surface. For many applications it is important that the free space photon can be coupled to SPPs in a controllable manner. In this Letter, we apply the concept of interfacial phase discontinuity for circularly polarizations on a metasurface to the design of a novel type of polarization dependent SPP unidirectional excitation at normal incidence. Selective unidirectional excitation of SPPs along opposite directions is experimentally demonstrated at optical frequencies by simply switching the helicity of the incident light. This approach, in conjunction with dynamic polarization modulation techniques, opens gateway towards integrated plasmonic circuits with electrically reconfigurable functionalities.Comment: 17 pages, 5 figures. Published on <Light:Science & Applications

Identification two novel nacrein-like proteins involved in the shell formation of the Pacific oyster Crassostrea gigas

Nacrein-like proteins have carbonic anhydrase (CA)-like domains, but their coding regions are flanked by inserted repeat sequence, such as Gly-X-Asn. Reportedly, nacrein-like proteins show the highest similarity to human carbonic anhydrase 1(α-CA1), possess CA catalytic functions, and play a key role in shell biomineralization. In the present study, two novel nacrein-like proteins were firstly identified from the shell-forming mantle of the Pacific oyster Crassostrea gigas. With numerous analyses, it was identified and characterized that both the nacrein-like proteins F1 and F2 were secreted and most closely related to the nacrein-like protein of California mussel Mytilus californianus via phylogenetic analysis. RT-PCR analysis showed that the nacrein-like proteins F1 and F2 were expressed in multiple tissues and the expression levels remarkably rose after entering the spat stage, which were basically consistent with the increase of calcite fractions in the total shell volume. Surprisingly, the Gly-X-Asn repeat domain, which is distinctive in most nacrein-like proteins, was absent in the two newly identified nacrein-like proteins in C. gigas and replaced with a series of acidic amino acids (D/E). Regardless, nacrein-like proteins in mollusks seem to be vital to the deposition of calcium carbonate and likely perform diverse functions. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11033-014-3298-z) contains supplementary material, which is available to authorized users

The application of artificial intelligence in glaucoma diagnosis and prediction

Artificial intelligence is a multidisciplinary and collaborative science, the ability of deep learning for image feature extraction and processing gives it a unique advantage in dealing with problems in ophthalmology. The deep learning system can assist ophthalmologists in diagnosing characteristic fundus lesions in glaucoma, such as retinal nerve fiber layer defects, optic nerve head damage, optic disc hemorrhage, etc. Early detection of these lesions can help delay structural damage, protect visual function, and reduce visual field damage. The development of deep learning led to the emergence of deep convolutional neural networks, which are pushing the integration of artificial intelligence with testing devices such as visual field meters, fundus imaging and optical coherence tomography to drive more rapid advances in clinical glaucoma diagnosis and prediction techniques. This article details advances in artificial intelligence combined with visual field, fundus photography, and optical coherence tomography in the field of glaucoma diagnosis and prediction, some of which are familiar and some not widely known. Then it further explores the challenges at this stage and the prospects for future clinical applications. In the future, the deep cooperation between artificial intelligence and medical technology will make the datasets and clinical application rules more standardized, and glaucoma diagnosis and prediction tools will be simplified in a single direction, which will benefit multiple ethnic groups

A New Alloy for High Performance Valve Steel for High Efficiency Compressors

In 2018 the International Energy Association IEA reported that air conditioning will be a major contributor for future electricity consumption (Birol, F. 2018). As recently seen in China, tougher legislation on energy efficiency for air conditioning and refrigeration is being introduced all the time. It is therefore crucial that new compressor models perform at the highest levels in terms of efficiency to reduce global energy consumption. The prerequisites to fulfill this legislation vary for the different applications such as rotary, reciprocating, scroll and linear compressors. However, to succeed in developing more energy efficient compressors, the ability to improve the performance of the flapper valves will play an important role. Furthermore, the current commercial alloys available for flapper valves may not be sufficient to meet these increasing demands. In the past, to improve the material fatigue properties, the development of high-performance flapper valve material has been focused around optimizing the metallurgical cleanliness, microstructure, surface finish and mechanical properties. Now research has been completed to develop a new alloy composition aiming to develop a material with further improved fatigue properties for flapper valve applications. The results from internal and external testing of the new alloy show significantly improved fatigue properties. Within this paper, some of the critical properties of the new alloy are presented and the test results are compared with other existing flapper valve steels on the market

Evaluation of translocation impacts on genetic patterns in farmed and naturalized populations of Mytilus galloprovincialis along the China coast: clues from mitochondrial cytochrome c oxidase I sequences

As an introduced species, Mytilus galloprovincialis has developed into self-sustaining naturalized populations and has been widely cultivated in northern China. The M. galloprovincialis aquaculture industry wholly depends on the movement of naturalized juveniles onto farms. It is, therefore, necessary to understand the genetic effect of continuous spats’ translocation. This study divided 12 localities of M. galloprovincialis along the China coast into three types of populations—farmed, naturalized adjacent farmed, and isolated—to investigate the genetic variation and differentiation. The genetic variability is reflected by haplotype diversity, nucleotide diversity, and the mean number of pairwise differences expressed as farmed populations > naturalized adjacent farmed populations > isolated populations. The Hierarchical analyses and Mantel-test indicated slight divergence between farmed and naturalized populations, northern and southern populations. The farmed and naturalized populations clustered into two separate categories in the neighbor-joining tree except two anthropogenically intervened localities. The present results suggest that the translocation practice positively affected genetic variability and played a vital role in shaping genetic composition. The information obtained in this study provides new insights into the impacts of the translocation culture model of marine mollusks

Prevalence and determinants of resistant hypertension among hypertensive patients attending a cardiology clinic in China: a prospective cross-sectional study

Purpose: To determine occurrence and determinants of resistant hypertension (RHT) among patients attending cardiology clinic of the affiliated hospital of Hangzhou Normal University, China.Methods: An observational prospective cross-sectional study was conducted among patients with hypertension attending the cardiology clinic over a period of 6 months. After identification of patients with RHT, various independent co-variants were tested by logistic regression in order to evaluate the determinants of RHT.Results: Out of 556 patients, 104 (18.7 %) patients had RHT while 67 (12.1 %) patients had uncontrolled blood pressure (BP) in spite of treatment with three antihypertensive drugs including a diuretic; 37 (6.6 %) patients had controlled BP with &gt; three drugs. Obesity (OR: 2.7, p = 0.002], duration of hypertension (OR: 1.8, p = 0.015], presence of diabetes mellitus (OR: 3.6, p &lt; 0.001) and ischemic heart disease (OR: 3.2, p = 0.001) were significant determinants of resistant hypertension in the study cohort.Conclusion: The prevalence of RHT found in this study is significantly high, thus indicating a need for greater attention of clinicians to this highly morbid condition. Obese patients and those suffering from diabetes mellitus, ischemic heart disease and chronic diseases should be evaluated for the presence of RHT. Early identification of such patients will provide sufficient time for clinicians to refer patients, as well as modify and/or intensify therapy.Keywords: Resistant hypertension, Risk factors, Hypertension, Stroke, Diabetes mellitus, Ischemic heart diseas

Transcriptomics and Fitness Data Reveal Adaptive Plasticity of Thermal Tolerance in Oysters Inhabiting Different Tidal Zones

Fine-scale adaptive evolution is always constrained by strong gene flow at vertical level in marine organisms. Rapid environmental fluctuations and phenotypic plasticity through optimization of fitness-related traits in organisms play important roles in shaping intraspecific divergence. The coastal systems experience strong variations in multiple abiotic environmental factors, especially the temperature. We used a typical intertidal species, Pacific oyster (Crassostrea gigas), to investigate the interaction between plasticity and adaptive evolution. We collected intertidal and subtidal oysters from two ecological niches and carried out common garden experiments for one generation. We identified fine-scale vertical adaptive divergence between intertidal and subtidal F1 progeny at both sites, based on different hierarchical phenotypes, including morphological, physiological, and molecular traits. We further quantified the global plasticity to thermal stress through transcriptomic analysis. The intertidal oysters exhibited slow growth rate. However, they showed high survival and metabolic rates under heat stress, indicating vertically fine-scale phenotypic adaptive mechanisms and evolutionary trade-offs between growth and thermal tolerance. Transcriptomic analysis confirmed that the intertidal oysters have evolved high plasticity. The genes were classified into three types: evolutionarily divergent, concordantly plastic, and adaptive plastic genes. The evolved divergence between intertidal and subtidal oysters for these gene sets showed a significant positive correlation with plastic changes of subtidal populations in response to high temperature. Furthermore, the intertidal oysters exhibited delayed large-scale increase in expressional plasticity than that in subtidal counterparts. The same direction between plasticity and selection suggests that the oysters have evolved adaptive plasticity. This implies that adaptive plasticity facilitates the oyster to adapt to severe intertidal zones. The oysters exposed to strong environmental variability are thermal tolerant and have high adaptive potential to face the current global warming. Our findings will not only provide new insights into the significant role of plasticity in adaptive evolution that can be extended to other marine invertebrates, but also provide basic information for oyster resources conservation and reef reestablishment

Use of waist to hip ratio in the determination of the body composition in preschool children in Latvian population

According to the World Health Organization (WHO), in 2008, the waist to hip ratio (WHR) has been suggested superior to the body mass index (BMI) in predicting the cardiovascular disease risk in adults and adolescents. There have been studies about the WHR in preschool children in the populations of Pakistan, Chile and Mexico; and it is not the WHO which recommended it as a routine method in preschool children.The present study includes 85 children (41 girls and 44 boys), aged 5 to 7 years, without any chronic conditions. Body height, body weight, waist circumference, hip circumference, triceps skinfold, abdominal skinfold and subscapular skinfold were measured. The WHR, the BMI, the sum of three skinfolds and the percentage of body fat (%BF) were calculated.It was found that the WHR decreased with age in girls; there were no specific changes found in the WHR with age in boys. The present study found no correlation in boys or girls between the WHR and the BMI; the WHR and the sum of three skinfolds; the WHR and the percentage of BF. There was also no correlation between the Z-scores of the BMI and Z-scores of the WHR.Conclusions. The WHR is a questionable body composition marker in preschool children in the Latvian population and must be evaluated separately from other body composition markers

Genomic DNA Extraction from in vivo Sampled Tissue of Pacific Oyster, Crassostrea gigas

Abstract As opposed to other animals, live bivalve shellfish cannot be sampled because of the high mortality associated with opening closed shells. In this paper, we present a new anesthesia method using an MgSO 4 seawater solution for sampling live bivalve shellfish. In our experiment, genomic DNA was successfully extracted from mantle tissues of sampled Pacific oyster (Crassostrea gigas) and the DNA was used as a template for polymerase chain reaction (PCR), which indicated that 3 mm 3 of mantle tissue was enough for DNA extraction and subsequent molecular biology testing. The survival rate after the in vivo sampling was high (83.3%), indicating that the sampling method caused only slight harm to the oysters. Thus, MgSO 4 anesthesia is a practical method for in vivo sampling of oysters and probably could be applied to other bivalve shellfish species as well, significantly promoting the application of molecular marker-assisted selection in bivalve shellfish breeding and the study of tissue injury and repair mechanisms in bivalve shellfish