A Duhamel Integral Based Approach to Identify an Unknown Radiation Term in a Heat Equation with Non-linear Boundary Condition

In this paper, we consider the determination of an unknown radiation term in the nonlinear boundary condition of a linear heat equation from an overspecified condition. First we study the existence and uniqueness of the solution via an auxiliary problem. Then a numerical method consisting of zeroth-, first-, and second-order Tikhonov regularization method to the matrix form of Duhamel\u27s principle for solving the inverse heat conduction problem (IHCP) using temperature data containing significant noise is presented. The stability and accuracy of the scheme presented is evaluated by comparison with the Singular Value Decomposition (SVD) method. Some numerical experiments confirm the utility of this algorithm as the results are in good agreement with the exact data

Individual differences in embodied distance estimation in virtual reality

There are important individual differences when experiencing VR setups. We ran a study with 20 participants who got a scale-matched avatar and were asked to blind-walk to a VR target placed 2.5 meters away. In such setups, people typically underestimate distances by approximately 10% when virtual environments are viewed through head mounted displays. Consistent with previous studies we found that the underestimation was significantly reduced the more embodied the participants were. However, not all participants developed the same level of embodiment when exposed to the exact same conditions

Comparative study on gonad development in rainbow trout (Oncorhynchus mykiss) reared in fresh and brackish water in the Yazd Province

Rainbow trout (Oncorhylichus mikiss) weidting 200±5 grams were used in this study to compare their gonad development in fresh and brackish water in Yazd Province. The culture period lasted 140 days from October to March 2003 during which time the temperature 03.8+0.6), pH (8.18±0.12) and dissolved oxygen (6.2+0.11) of fresh and brackish water were kept nearly constant. The salinity of fresh and brackish water was 0.4 -0.5 and 14.3-14.7ppt respectively. The fish were fed common commercial trout food (Chineh GFT2) based on temperature and biomass. Histological studies indicated that the gonad development is accelerated in brackish water where the males mature two month eal her than those reared in freshwater. The gonadosomatic index (G51) also affirmed the gonad development (P<0.05)

Rapid, cost-effective, sensitive and quantitative detection of Acinetobacter baumannii from pneumonia patients

BACKGROUND AND OBJECTIVES: Pneumonia with Acinetobacter baumannii has a major therapeutic problem in health care settings. Decision to initiate correct antibiotic therapy requires rapid identification and quantification of organism. The aim of this study was to develop a rapid and sensitive method for direct detection of A. baumannii from respiratory specimens. MATERIALS AND METHODS: A Taqman real time PCR based on the sequence of bla(oxa-51) was designed and used for direct detection of A. baumannii from 361 respiratory specimens of patients with pneumonia. All specimens were checked by conventional bacteriology in parallel. RESULTS: The new real time PCR could detect less than 200 cfu per ml of bacteria in specimens. There was agreement between the results of real time PCR and culture (Kappa value 1.0, p value<0.001). The sensitivity, specificity and predictive values of real time PCR were 100%. The prevalence of A. baumannii in pneumonia patients was 10.53 % (n=38). Poly-microbial infections were detected in 65.71% of specimens. CONCLUSION: Acinetobacter baumannii is the third causative agent in nosocomial pneumonia after Pseudomonas aeroginosa (16%) and Staphylococcus aureus (13%) at Tehran hospitals. We recommend that 104 CFU be the threshold for definition of infection with A. baumannii using real time PCR

Population dynamics of the Spanish mackerel (Scomberomorus commerson) in coastal waters of Oman Sea

Length composition data of narrow-barred Spanish mackerel, Scomberomorus commerson (Lacepede 1800), landed between April 2002 to March 2004, were monthly used to estimate the growth, mortality and exploitation parameters of the stock. Maximum fork length and weight were 170 cm and 38 kg, respectively. Nonlinear least square fitting provided a complete set of von Bertalanffy growth estimates: L¥=178 cm (FL); K=0.28 and to= -0.36 years. The estimated value of total mortality based on length converted catch curve using these growth parameters is Z=0.95 year-I. Natural mortality based on growth parameters and mean environmental temperature (T=26.5°C) is M=0.36 year-1. Furthermore, the annual instantaneous fishing mortality rate of 0.59 year-1 was by far in excess of the precautionary target (Fopt=0.18 year-1) and limit (Flimit=0.24 year-1) biological reference points, indicating that the resource is heavily over-exploited and the management of this species should be implanted rapidly if they are to remain sustainable

Biochemical and histological studies of over-ripened oocyte in the Caspian brown trout (Salmo trutta caspius) to determine biomarkers for egg quality

The aims of the present study were to determine the best time for egg stripping after ovulation and to study oocyte over-ripening in the Caspian brown trout (Salmo trutta caspius). Eggs were retained in the female abdominal cavity for 40 days post ovulation (DPO). Partial volumes of eggs stripped from 10 individually identified females at 10 days intervals and fertilized with a pool of semen obtained from 8 males. The biochemistry and histology of the eggs and the biochemistry of the ovarian fluid were studied. The eyeing and hatching rate of the eggs declined with over-ripening time, which decreased from 90.60±6.28% for eyeing and 86.33±6.82% for hatching in newly ovulated eggs (0–10 DPO) to 1.34±0.67% for eyeing and 0.98±0.49% for hatching in over-ripened eggs (30–40 DPO). However, larval abnormalities remained constant for 30 days after ovulation. During the course of oocyte over-ripening, the pH of the ovarian fluid significantly decreased and the concentration of glucose, protein, calcium, iron, and aspartate aminotransferase activity significantly increased. Moreover, the concentration of protein, triglycerides, and aspartate aminotransferase activity in the eggs changed with over-ripening. In the newly ovulated eggs, the yolk consisted of homogenous tissue and its perivitelline space diameter had no considerable differences. With over-ripening, the yolk became heterogeneous, and while chorion diameter did not change, the perivitelline space diameter varied among different areas. The present study demonstrated that the best time to take Caspian brown trout eggs after ovulation at 7±0.6°C was up to 10 DPO. Among the studied parameters of the egg and ovarian fluid, egg quality was related to both ovarian fluid parameters (pH, protein, aspartate aminotransferase, glucose, cholesterol, triglycerides, calcium) and egg parameters (iron, aspartate aminotransferase), suggesting that these parameters can be used as egg quality biomarkers for Caspian brown trout

Study of kidney and gill function in Salmo trutta caspius fingerlings after move to the Caspian Sea

Caspian trout (Salmo trutta caspius) is an anadromous and valuable fish species in the Caspian Sea. Electrolytes concentration (Mg2+ and Ca2+) and kidney and gill development trend were studied in different weight groups. Specimens in 4 weight groups 5, 10, 15 and 20g. Each trial was done in 3 replicates. The observation of kidney glomeruli in histological sections showed that the diameter of glomeruli in all weight groups in Caspian water decreased after 72h adaptation period (P0.05), although in other groups (10, 15 and 20g) a significant increase in chloride cell's number and size was detected. The number of chloride cells on gill's secondary lamellas varied between 3 to 7 (in two gills lamellas)

I'm a Giant: Walking in Large Virtual Environments at High Speed Gains

Advances in tracking technology and wireless headsets enable walking as a means of locomotion in Virtual Reality. When exploring virtual environments larger than room-scale, it is often desirable to increase users' perceived walking speed, for which we investigate three methods. (1) Ground-Level Scaling increases users' avatar size, allowing them to walk farther. (2) Eye-Level Scaling enables users to walk through a World in Miniature, while maintaining a street-level view. (3) Seven-League Boots amplifies users' movements along their walking path. We conduct a study comparing these methods and find that users feel most embodied using Ground-Level Scaling and consequently increase their stride length. Using Seven-League Boots, unlike the other two methods, diminishes positional accuracy at high gains, and users modify their walking behavior to compensate for the lack of control. We conclude with a discussion on each technique's strength and weaknesses and the types of situation they might be appropriate for

The comparison of LC50 of clove essence and MS222 in Acipenser persicus, Oncorhynchus mykiss and Cyprinus carpio

The LC50 of two anaesthetic agents, clove essence and MS222, on the cultivated fish species, Acipenser persicus, Oncorhynchus mykiss, Cyprinus curpio were estimated. 640 samples of above mentioned species were used exposing anaesthetic agents for 2 minutes.LC50 of clove essence and MS222 for sturgeon estimated 297 and 291 ppm, for common carp was 271 and 272 ppm; and for rainbow trout Was 199 and 207 pmm, respectively. Significant difference was found only between LC50 of MS222 in rainbow trout with LC50 of both agents in two other species. Also, the results showed that there is no significant difference on poisoning of two applied drugs in all above mentioned species; with comparing different species, rainbow trout had lower tolerance to both anesthetics

Non-medial infectious orbital cellulitis: etiology, causative organisms, radiologic findings, management and complications

Background: Orbital cellulitis is an ophthalmic emergency, which is associated with vision-threatening adverse effects. The purpose of this study is investigating etiology, radiologic findings, management and complications of patients with non-medial orbital cellulitis. Method: A retrospective medical record and radiologic file review of patients with infectious orbital cellulitis was performed to detect all patients with non-medial orbital cellulitis who referred to Khalili hospital from 2016 to 2019. Age, sex, origin of infection, size of collection or abscess, medical or surgical management, microbiology, first and final best-corrected visual acuity, duration of admission, and complications was recorded. Patients divided into two groups; medical management and surgical management groups and all of data compared between in this groups. Results: Of ninety-six patients with infectious orbital cellulitis, 23 cases (14 male, 9 female) were included. Five patients (21.7) were managed medically and 18 patients (78.3) were managed surgically. Patients� age range was 5�70 years old. Most common location for non-medial cellulitis was superior space (66.7 in surgical and 40 in medical group; p = 0.511). In 13 cases of surgical group (72.3) were detected microorganisms. The mean ± SD of collection volume in medical group were 476.5 ± 290.93 mm3 and 2572.94 ± 1075.75 mm3 in surgical group (p &lt; 0.001). Ten patients in surgical group had compressive optic neuropathy. The mean ± SD of collection volume was 3204.97 ± 879.88 mm3 in patient with compressive optic neuropathy and 1280.43 ± 880.68 mm3 in patient without compressive optic neuropathy (P &lt; 0.001). One case complicated by subdural empyema and another case progressed to necrotizing fasciitis. Conclusion: Non-medial orbital cellulitis is an uncommon but sight-threatening and life-threatening condition. Timely diagnosis and accurate management reduce morbidity and mortality. Combined surgery for patients with superior or supra-temporal and large non-medial abscess is recommended. © 2020, The Author(s)