188 research outputs found
Bandgap Narrowing in Quantum Wires
In this paper we consider two different geometry of quasi one-dimensional
semiconductors and calculate their exchange-correlation induced bandgap
renormalization (BGR) as a function of the electron-hole plasma density and
quantum wire width. Based on different fabrication scheme, we define suitable
external confinement potential and then leading-order GW dynamical screening
approximation is used in the calculation by treating electron-electron Coulomb
interaction and electron-optical phonon interaction. Using a numerical scheme,
screened Coulomb potential, probability of different states, profile of charge
density and the values of the renormalized gap energy are calculated and the
effects of variation of confinement potential width and temperature are
studied.Comment: 17 Pages, 4 Figure
Relationship between C-reactive protein and carotid artery intima media thickness in polycystic ovarian syndrome patients
Objective: To determine relationship between CRP (C-reactive protein) concentration and CIMT (carotid artery intima media thickness) in young PCOS (polycystic ovary syndrome) females. Design: Cross-sectional Setting: Infertility outpatient clinic Patients: 70 PCOS patients (20-39 years old) and 70 healthy subjects as control. Interventions: CIMT was measured by Doppler ultrasound. Main outcome measure: Relationship between increased CRP level and CIMT. Results: Mean (±SD) serum CRP level was higher in PCOS patents (5.2 ± 2.8 mg/dL) in comparison to controls (4.9 ± 1.7 mg/dL), but the difference was not statistically significant (P= 0.482). However, mean (±SD) CIMT was significantly higher in PCOS group (0.65 ± 0.11 mm) compared to controls (0.59 ± 0.21 mm); P= 0.016. Although with increased CRP level, CIMT increased in PCOS patients, the relationship was not statistically significant (P= 0.065, r= 0.886). Also there was a relationship between age and CIMT but it was not statistically significant (P= 0.07, r= 0.215). However, relationships between CIMT and BMI (P= 0.04, r= 0.571) and between CIMT and waist circumference (P= 0.028, r= 0.36) were statistically significant. Based on regression analysis serum CRP level (P= 0.055, 95 CI= 1.589-73.713) and BMI (P= 0.051, 95 CI= 1.379-2.412) were independent variables which affected CIMT. Conclusion: CRP was elevated in PCOS patients compared to controls, but the difference was not statistically significant. Therefore, measuring CRP in PCOS patients should be interpreted with keeping in mind other CVD risk factors in these patients such as fasting blood sugar, lipid profile, and most importantly BMI
Separation of Crocin/Betanin Using Aqueous Two-phase Systems Containing Ionic Liquid and Sorbitol
Betanin and crocin, two food additives with attractive colors, are bioactive compounds of plants that are widely used in food, pharmaceutical, and medical industries. These bioactive pigments are sensitive to light, heat, organic solvents, and pH. It seems that a benign economic method is needed to extract these biomolecules, especially for industrial applications. The aqueous two-phase system (ATPS) is a liquid-liquid extraction technique that has shown its potential in recent years to extract and separate biomolecules. In this study, an ATPS consisting of carbohydrate (sorbitol) and ionic liquid (tetrabutyl phosphonium bromide) has been proposed as a new separation system with unique properties to study the partition coefficient of crocin and betanin. The results indicated that crocin and betanin had more tendency to the ionic liquid (IL)-rich phase and carbohydrate-rich phase, respectively. The influence of the concentration of IL and sorbitol on the partition coefficient was studied. The results showed that an increase in the tie-line length (concentrations) increased the partition coefficient of crocin and betanin. Enhancement in temperature increased the partition coefficient of crocin. The highest values of crocin recovery (97.55 %) and partition coefficient (39.85) at 308 K show that our proposed ATPS can be considered for crocin separation in one step
Blowing in the Wind: CycleNet for Human Cinemagraphs from Still Images
Cinemagraphs are short looping videos created by adding subtle motions to a static image. This kind of media is popular and engaging. However, automatic generation of cinemagraphs is an underexplored area and current solutions require tedious low-level manual authoring by artists. In this paper, we present an automatic method that allows generating human cinemagraphs from single RGB images. We investigate the problem in the context of dressed humans under the wind. At the core of our method is a novel cyclic neural network that produces looping cinemagraphs for the target loop duration. To circumvent the problem of collecting real data, we demonstrate that it is possible, by working in the image normal space, to learn garment motion dynamics on synthetic data and generalize to real data. We evaluate our method on both synthetic and real data and demonstrate that it is possible to create compelling and plausible cinemagraphs from single RGB images
Application of the Fokker-Planck molecular mixing model to turbulent scalar mixing using moment methods
An extended quadrature method of moments using the beta kernel density function (beta-EQMOM) is used to approximate solutions to the evolution equation for univariate and bivariate composition probability distribution functions (PDFs) of a passive scalar for binary and ternary mixing. The key element of interest is the molecular mixing term, which is described using the Fokker-Planck (FP) molecular mixing model. The direct numerical simulations (DNSs) of Eswaran and Pope [ Direct numerical simulations of the turbulent mixing of a passive scalar, Phys. Fluids 31, 506 (1988)] and the amplitude mapping closure (AMC) of Pope [ Mapping closures for turbulent mixing and reaction, Theor. Comput. Fluid Dyn. 2, 255 (1991)] are taken as reference solutions to establish the accuracy of the FP model in the case of binary mixing. The DNSs of Juneja and Pope [ A DNS study of turbulent mixing of two passive scalars, Phys. Fluids 8, 2161 (1996)] are used to validate the results obtained for ternary mixing. Simulations are performed with both the conditional scalar dissipation rate (CSDR) proposed by Fox [Computational Methods for Turbulent Reacting Flows (Cambridge University Press, 2003)] and the CSDR from AMC, with the scalar dissipation rate provided as input and obtained from the DNS. Using scalar moments up to fourth order, the ability of the FP model to capture the evolution of the shape of the PDF, important in turbulent mixing problems, is demonstrated. Compared to the widely used assumed beta-PDF model [S. S. Girimaji, Assumed beta-pdf model for turbulent mixing: Validation and extension to multiple scalar mixing, Combust. Sci. Technol. 78, 177 (1991)], the beta-EQMOM solution to the FP model more accurately describes the initial mixing process with a relatively small increase in computational cost
First report of Dinocampus coccinellae (Hym.: Braconidae) from Iran
در نمونهبرداریهایی که طی شهریور تا آبان ماه 1389 در مزرعه تحقیقاتی دانشگاه بوعلی سینا در دستجرد همدان جهت بررسی میزان پارازیتیسم کفشدوزک Hippodamia variegata (Goeze) (Col.: Coccinellidae) انجام شد، زنبور پارازیتوئید Dinocampus coccinellae (Schrank) جمعآوری گردید. این زنبور برای اولینبار از ایران گزارش میشود
Life history parameters of Thrips tabaci (Thys.: Thripidae) on cucumber, sweet pepper and eggplant under laboratory conditions
Onion thrips, Thrips tabaci Lindeman, is one of the most important pests of vegetables and ornamentals all over the world. Its role has been proved in the transmission of different viruses to several plants. In this study, life history parameters of T. tabaci were calculated on three host plants, cucumber, sweet pepper and eggplant. Experiments were conducted at 25 ± 1οC, 60 ± 10% R.H. and photoperiod of 16: 8 (L: D) hours. The results showed that host plants affect life history of onion thrips significantly. Intrinsic rate of population increase (rm) was 0.296, 0.158 and 0.234 female on female per day on cucumber, sweet pepper and eggplant respectively. Other parameters like λ (finite rate of increase) were 1.334, 1.171 and 1.264; T (mean generation time) were 14.879, 19.092 and 16.779; DT (doubling time) were 2.343, 4.384 and 2.956 days. Finally, R0 (net reproductive rate) was 81.581, 20.461 and 51.141 female/female in one generation. With regard to highly significant effect of host plants on life history parameters of onion thrips, it is probable that this problem could be used for control of onion thrips on sweet pepper more effectively than on cucumber and eggplant
Studies on Dibenzylamines as Inhibitors of Venezuelan Equine Encephalitis Virus
Alphaviruses are arthropod-transmitted members of the Togaviridae family that can cause severe disease in humans, including debilitating arthralgia and severe neurological complications. Currently, there are no approved vaccines or antiviral therapies directed against the alphaviruses, and care is limited to treating disease symptoms. A phenotypic cell-based high-throughput screen was performed to identify small molecules that inhibit the replication of Venezuelan Equine Encephalitis Virus (VEEV). The compound, 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-N-(3-fluoro-4-methoxybenzyl)ethan-1-amine (1), was identified as a highly active, potent inhibitor of VEEV with an effective concentration for 90% inhibition of virus (EC90) of 0.89 μM and 7.49 log reduction in virus titers at 10 μM concentration. These data suggest that further investigation of compound 1 as an antiviral therapeutic against VEEV, and perhaps other alphaviruses, is warranted. Experiments suggested that the antiviral activity of compound 1 is directed at an early step in the VEEV replication cycle by blocking viral RNA and protein synthesis
Bio-ecological study of river estuaries in Guilan province
The Caspian Sea with brackish water is known as typical environment due to geo position, precious biota and the largest land-enclosed drainage area in the world. Macrobenthos were performed the main group of the Caspian Sea fauna. While they use as environmental bio-assessment, they have not completely studied in the Caspian Sea especially in estuaries environments. In this survey were studied eighteen river estuaries in Guilan province off Caspian sea southwest including Asrara, Chelevand, Lemir, Havigh, Shirabad, Khotbesara, Lisar, Karganroud, Navroud, Nokandekeh, Sefidrud, Heshmatrud, Langerud, Polerud and Chabokrud. The macro-invertebrate sampling was conducted seasonally at eight stations during autumn 2008 to autumn 2009. The macrobenthos organisms were identified as possible level in genus or species. The Shannon Wiener diversity and the Hilsenhoff biotic indices were used for evaluation of environmental quality. In this study, 69 genus identified that belong to 36 families and 16 orders. The most presentation of genus belongs to Chironomidae family with twenty six genus while others families were included forty three genus. The most average of macro-invertebrate abundance belong to order of Diptera with 35 %, subsequently the abundance of Amphipoda and Bivalvia orders occupied the second rank with 8.2 %. Orders Polychaeta, Oligochaeta and Cumacea had a low abundance during the study, however the Polychaeta showed a high abundance in some seasons and stations (up to 25%). The Plecoptera was rarely observed in some stations with high abundance. The Stenogammarus genus had the normally distribution during study, while Chironomidae genera as Eukifferiella and Cricotopus were measured in the high abundance during autumn 2008 to spring 2009. While Streblospio and Limnodrilus had the high presentation during winter and spring 2009, Cerastoderma sp. showed a high percentage in spring and summer 2009. The result of Shannon Wiener index values showed a significantly difference among regions for most seasons. There was also observed significantly difference for diversity values among stations in different seasons. According to Hilsenhoff biotic index for water quality classification; the most stations had good quality in spring 2009, while they were slightly and moderately good condition in winter 2009. The water quality of the Caspian Sea stations was in good condition as compared with the rivers estuary stations
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