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Optimal harvesting for a single-species population governed by Gompertz law:Influence of environmental fluctuation and limited harvesting capacity

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International Journal of Biomathematics 2019年第2期12卷 115-142页

作者： P.d.N.Srinivasu simon d.Zawka Sri Sathya Sai University for Human Excellence Navanihala Village Okali PostKamalapur Taluk Gulbarga DistrictKarnataka 585313India department of Mathematics Andhra University Visakhapatnam 530003India department of Mathematics Ar ba Minch University Arba MinchEthiopia

This work presents an optimal harvesting problem associated with a single-species population governed by Gompertz law in a seasonally fluctuating *** influence of environmental fluctuation is accommodated by choosing the coefficients in the differential equation to be periodic functions with the same period and restriction on the harvesting effort is accommodated by considering binding constraints on the control ***,a linear optimal control problem has been considered where the state dynamics is governed by Gompertz equation and the control variable is subject to the binding *** the help of maximum principle and the concept of blocked intervals,an optimal periodic solution has been obtained which is followed by the construe tion of optimal solution using the theory of most rapid *** results of the study are demonstrated through numerical simulations.

关键词： Optimal harvesting Gompertz equation seasonality binding constraint blocked intervals

Collembola communities and soil conditions in forest plantations established in an intensively managed agricultural area

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Journal of Forestry Research 2021年第5期32卷 1819-1832页

作者： István Harta Barbara simon Szergej Vinogradov dániel Winkler Institute of Environmental Science Szent István UniversityGödöllőHungary Institute of Methodology Szent István UniversityGödöllőHungary Institute of Wildlife Management and Vertebrate Zoology University of SopronSopronHungary

The challenges of a changing climate have directed greater attention to afforestation,but the effects of afforestation on soil fertility and soil biota have not been fully *** explore changes in the soil conditions in two 20-year-old forest plantations established in formerly intensively fertilized plots of agricultural land,we focused on the current developmental state of the sites that received the most fertilizer and evaluated soil properties and Collembola(springtails)*** oak(Quercus petraea)and black locust(Robinia pseudoacacia)that had been planted in the afforestation sites were assessed for differences between plantations of native and invasive *** adjacent reference associations,including forests and open habitats,were also analyzed and *** showed that the soils in the two afforested sites were similar in their properties and Collembola communities to those of the control cultivated forests,but differed from each other in pH,calcium,phosphorus,and ammonium *** available potassium and phosphorus contents in the soil of the sessile oak plantation were still high,while the soil organic matter content was adequate(SOM>2.0%)in both *** richness of Collembola ranged from 18 in the cultivated arable land to 43 in the relict *** a few species typical for forests(e.g.,Neanura muscorum,Isotomiella minor,Entomobrya muscorum)were detected in the young plantations,while species characteristic of open habitats(e.g.,Protaphorura campata,Lepidocyrtus cyaneus)occurred as *** more individuals and species of Collembola were present in the soil of young plantations than in arable fie.ds,their community diversities were significantly lower compared to the control forest *** community diversity differed significantly also between the two plantation types(with native and non-native tree species).Mean abundance in the afforested sites was about 2.5 times higher than in the cultiv

关键词： Afforestation diversity Fertilizers Soil fauna Soil properties Springtails

Modified shear cell for characterization of the rheological behavior of particulate networks under compression

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Particuology 2020年第4期18卷 1-9页

作者： simon Hammerich Anthony d.Stickland Benjamin Radel Marco Gleiss Hermann Nirschl Institute of Mechanical Process Engineering and Mechanics Karlsruhe Institute for Technology(KIT)Strasse am Forum 876131 KarlsruheGermany Particulate Fluids Processing Centre Department of Chemical EngineeringThe University of Melbourne3010Australia

Knowledge of the rheological behavior of saturated particulate networks is crucial for every process in which a particulate network is built-up,dewatered,or transported,as in a decanter ***,difficulties arise as to how to characterize the material *** far,no standardized method or measurement device has *** this work,the requirements for a useful device are discussed,followed by the design of a modified shear cell for a Schulze ring shear tester *** and its measurement *** experiments under normal load with different sediments consisting of inorganic and organic particles whose material properties strongly affect the rheological behavior were *** results demonstrate the potential of the modified shear ***,current challenges in characterization are *** characterization possibilities of the developed shear cell are a further step toward understanding the theological behavior of liquid-saturated particulate networks.

关键词： Sediment rheology Saturated particulate network Shear cell Shear compression Rheological behavior

Nest predators, nest-site selection and nest success of the Emei Shan Liocichla(Liocichla omeiensis), a vulnerable babbler endemic to southwestern China

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Chinese Birds 2016年第3期7卷 161-166页

作者： Yiqiang Fu Benping Chen simon d.dowell Zhengwang Zhang Sichuan Institute Key Laboratory for Protecting Endangered Birds in the Southwest Mountains College of Life Sciences Leshan Normal University Laojunshan National Nature Reserve Administration North of England Zoological Society Chester Zoo Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering College of Life Sciences Beijing Normal University

Background: The Emei Shan Liocichla(Liocichla omeiensis) is a globally vulnerable babbler, endemic to southwestern China. We investigated its nest predators, nest-site selection and nest success at the Laojunshan National Nature Reserve in Sichuan, China in order to identify the precise nesting-habitat requirements of the species, and to test whether the nest-site-selection cues, preferred by the Emei Shan Liocichla, are positively associated with nest ***: We used infrared cameras to determine nest predators. We compared the microhabitat attributes between nest and random sites, as well as successful and failed nests. We used Binary Logistic Regression to determine the most important variables affecting nest-site selection of the Emei Shan Liocichla. We used the nest survival analysis in Program MARK to estimate daily nest survival rates(dSR). Nest success was calculated using the Mayfie.d ***: In total 56 nests were found. The dSR for all nests that contained at least one egg was 0.9564 ± 0.0091(95 % CI 0.9346–0.9711)(n = 40), while the total nest success was 27.5 %. We identified four categories of predators in 10 nest predation events, i.e. squirrels(n = 5), snakes(n = 3), raptors(n = 1) and wasps(n = 1). We found that:(1) nest predation was the primary reason for nest failure of the Emei Shan Liocichla,(2) tree cover, bamboo cover, liana abundance and distance to forest edge or gap were the most important variables affecting nest-site selection of this species, and(3) the nest-site-selection variables we measured appeared not to be positively associated with nest ***: Our findings suggest that the Emei Shan Liocichla tended to select nest sites near forest edges or gaps with good concealment and that nest-site selection by this species was nonrandom but not necessarily adaptive. Reducing forest-edge development and protecting bamboo stands should be effective for conservation of this species.

关键词： Nest predator Nest-site selection Nest success Liocichla omeiensis Laojunshan Nature Reserve

Looking into the future of Nanoelectronics in the diversification Efficient Era

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Science China(Information Sciences) 2016年第6期59卷 6-19页

作者： simon dELEONIBUS Universit′es Grenoble Alpes CEA LETIMINATEC Campus

The linear scaling of CMOS has encountered, since its beginning, many hurdles which request new process modules, driven mainly by the maximization of energy efficiency. Fabrication at the sub 10 nm node level will request Intrinsic Variability approaching to zero. The rapid growth of mobile, multifunctional and autonomous systems is hardly demanding to reach Zero Power consumption. The solutions to integrate Thin Film based devices, architectures and systems in order to face these challenges are described.

关键词： CMOS thin films heterogeneous integration NEMS 3d integration sequential parallel zero intrinsic variability zero power systems

Potential for natural and enhanced attenuation of sulphanilamide in a contaminated chalk aquifer

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Journal of Environmental Sciences 2017年第12期29卷 39-48页

作者： Karen A.Bennett simon d.Kelly Xiangyu Tang Brian J.Reid School of Environmental Sciences University of East AngliaNorwich Research ParkNorwich NR4 7TJUK Food and Environmental Protection Laboratory International Atomic Energy Agency1400 ViennaAustria Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academyof SciencesChengdu 610041China

Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry（IRMS）method was developed to evaluate the extent of biodegradation of the antibiotic,sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ^（13）C of8.44‰ from-26.56（at the contaminant source） to-18.12‰（300 m downfie.d of the source）.These results confirm reductions in sulphanilamide concentrations（from 650 to 10 mg/L）across the contaminant plume to be attributable to biodegradation（56%） vs. other natural attenuation processes, such as dilution or dispersion（42%）. To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity（~50% mineralisation） to degrade sulphanilamide under high（263 mg/L）, moderate（10 mg/L） and low（0.02 mg/L） substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions.

关键词： Antibiotics Sulphonamide Groundwater contamination Biodegradation Stable isotope fractionation IRMS

Non-invasive means of measuring hepatic fat content

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World Journal of Gastroenterology 2008年第22期14卷 3476-3483页

作者： Sanjeev R Mehta E Louise Thomas Jimmy d Bell desmond G Johnston simon d Taylor-Robinson division of Medicine Imperial College London St Mary's Campus Praed Street London W2 1NY United Kingdom Imaging Sciences depart-ment Division of Clinical Sciences Imperial College London Hammersmith Campus Du Cane Road London W12 OHS United Kingdom

Hepatic steatosis affects 20% to 30% of the general adult population in the western world. Currently, the technique of choice for determining hepatic fat deposition and the stage of fibrosis is liver biopsy. However, it is an invasive procedure and its use is limited, particularly in children. It may also be subject to sampling error. Non-invasive techniques such as ultrasound, computerised tomography (CT), magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H MRS) can detect hepatic steatosis, but currently cannot distinguish between simple steatosis and steatohepatitis, or stage the degree of fibrosis accurately. Ultrasound is widely used to detect hepatic steatosis, but its sensitivity is reduced in the morbidly obese and also in those with small amounts of fatty infiltration. It has been used to grade hepatic fat content, but this is subjective. CT can detect hepatic steatosis, but exposes subjects to ionising radiation, thus limiting its use in longitudinal studies and in children. Recently, magnetic resonance (MR) techniques using chemical shift imaging have provided a quantitative assessment of the degree of hepatic fatty infiltration, which correlates well with liver biopsy results in the same patients. Similarly, in vivo 1H MRS is a fast, safe, non-invasive method forthe quantification of intrahepatocellular lipid (IHCL) levels. Both techniques will be useful tools in future longitudinal clinical studies, either in examining the natural history of conditions causing hepatic steatosis (e.g. non-alcoholic fatty liver disease), or in testing new treatments for these conditions.

关键词： Adipose tissue Ectopic fat Hepatic fat Insulin resistance Ultrasound Computerised tomography Magnetic resonance imaging Magnetic resonance spectroscopy

Integrated optical-readout of a high-Q mechanical out-of-plane mode

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Light(Science & Applications) 2022年第10期11卷 2485-2491页

作者： Jingkun Guo simon Groblacher Kavli Institute of Nanoscience Department of Quantum NanoscienceDelft University of Technology2628CJ DelftThe Netherlands

The rapid development of high-QM macroscopic mechanical resonators has enabled great advances in *** improvements could allow for quantum-limited or quantum-enhanced applications at ambient *** of the remaining challenges include the integration of high-QM structures on a chip,while simultaneously achieving large coupling strengths through an optical ***,we present a versatile fabrication method,which allows us to build fully integrated optomechanical *** place a photonic crystal cavity directly above a mechanical resonator with high-QM fundamental out-of-plane mode,separated by a small *** highly confined optical fie.d has a large overlap with the mechanical mode,enabling strong optomechanical interaction ***,we implement a novel photonic crystal design,which allows for a very large cavity photon number,a highly important feature for optomechanical experiments and sensor *** versatile approach is not limited to our particular design but allows for integrating an out-of-plane optical read-out into almost any device ***,it can be scaled to large arrays and paves the way to realizing quantum experiments and applications with mechanical resonators based on high-QM out-of-plane modes alike.

关键词： optical resonator mode

Morphometric and meristic variation in two congeneric archer fishes Toxotes chatareus (Hamilton 1822) and Toxotes jaculatrix (Pallas 1767) inhabiting Malaysian coastal waters

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第11期11卷 871-879页

作者： K.d.simon Y.BAKAR S.E.TEMPLE A.G.MAZLAN Marine Science Programme School of Environmental and Natural Resource SciencesFaculty of Science and TechnologyUniversiti Kebangsaan Malaysia Biology Programme School of Biological SciencesUniversiti Kebangsaan Malaysia School of Biomedical Sciences University of Queensland Marine Ecosystem Research Centre Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia

A simple yet useful criterion based on external markings and/or number of dorsal spines is currently used to differentiate two congeneric archer fish species Toxotes chatareus and Toxotes *** we investigate other morphometric and meristic characters that can also be used to differentiate these two *** component and/or discriminant functions revealed that meristic characters were highly correlated with pectoral fin ray count,number of lateral line scales,as well as number of anal fin *** results indicate that *** can be distinguished from *** by having a greater number of lateral line scales,a lower number of pectoral fin rays,and a higher number of anal fin *** contrast,morphometric discriminant analyses gave relatively low distinction:76.1% of fish were ascribed to the correct species *** observed morphometric differences came from the dorsal and anal spines lengths,with *** having shorter dorsal and longer anal spines than ***,meristic traits were more useful than morphometrics in differentiating the two species;nevertheless,meristics and morphometrics together provide information about the morphological differentiation between these two closely related archer fishes.

关键词： Archer fish Toxotes chatareus Toxotes jaculatrix Species identification Multivariate analysis