Development of an artificial neural network model to predict CO2 minimum miscibility pressure

Utiskivanje plina pod uvjetima miješanja je najraširenija metoda povećavanja iscrpka nafte, a njegova je primjena sve uočljivija u proizvodnji nafte diljem svijeta. Određivanje minimalnog tlaka miscibilnosti (MMP), kao glavnoga parametra u ovim projektima, je problem bez poznatog izravnog rješenja. Dostupne eksperimentalne metode oduzimaju mnogo vremena, a isto tako ni ne postoji neka univerzalna metoda. Dosad su istraživači pokušavali naći parametarsku korelaciju između različitih izravno mjerljivih parametara poput sastava injektiranog plina, temperature ležišta i sastava fluida u ležištu. Međutim, radi složene prirode ove pojave, predložene korelacije nisu točne ni pouzdane. Napravljeni su pokušaji korištenja umjetnih neuronskih mreža (ANNs) za utvrđivanje odnosa, koji možda postoje između MMP, plina i sastava ležišnog fluida i temperature ležišta. Arhitektura mreže temeljene na radijalnoj baznoj funkciji (RBF) uspješno je korištena za predviđanje CO2 MMP (minimalni tlak miscibilnosti nafte i CO2).Miscible gas injection is among the most widely used enhanced oil recovery techniques, and its applications are increasingly visible in oil production worldwide. Characterizing the Minimum Miscibility Pressure (MMP) as a main parameter in these projects is a problem with no direct known solution. Available experimental methods are very time-consuming and also there is no universal method. To date, investigators have tried to find parametric correlation between different direct measurable parameters such as injected gas composition, reservoir temperature and reservoir fluid composition. However, due to complex nature of the phenomena, the proposed correlations are not accurate and reliable. Attempts are made to utilize artificial neural networks (ANNs) for identification of the relationship, which may exist between MMP, gas and reservoir fluid composition and reservoir temperature. The radial basis function (RBF) neural network architecture has been used successfully in predicting the CO2 MMP

'The difference in determinants of Chlamydia trachomatis and Mycoplasma genitalium in a sample of young Australian women.'

BACKGROUND Differences in the determinants of Chlamydia trachomatis ('chlamydia') and Mycoplasma genitalium (MG) genital infection in women are not well understood. METHODS A cohort study of 16 to 25 year old Australian women recruited from primary health care clinics, aimed to determine chlamydia and MG prevalence and incidence. Vaginal swabs collected at recruitment were used to measure chlamydia and MG prevalence, organism-load and chlamydia-serovar a cross-sectional analysis undertaken on the baseline results is presented here. RESULTS Of 1116 participants, chlamydia prevalence was 4.9% (95% CI: 2.9, 7.0) (n = 55) and MG prevalence was 2.4% (95% CI: 1.5, 3.3) (n = 27). Differences in the determinants were found - chlamydia not MG, was associated with younger age [AOR:0.9 (95% CI: 0.8, 1.0)] and recent antibiotic use [AOR:0.4 (95% CI: 0.2, 1.0)], and MG not chlamydia was associated with symptoms [AOR:2.1 (95% CI: 1.1, 4.0)]. Having two or more partners in last 12 months was more strongly associated with chlamydia [AOR:6.4 (95% CI: 3.6, 11.3)] than MG [AOR:2.2 (95% CI: 1.0, 4.6)] but unprotected sex with three or more partners was less strongly associated with chlamydia [AOR:3.1 (95%CI: 1.0, 9.5)] than MG [AOR:16.6 (95%CI: 2.0, 138.0)]. Median organism load for MG was 100 times lower (5.7 × 104/swab) than chlamydia (5.6 × 10⁶/swab) (p < 0.01) and not associated with age or symptoms for chlamydia or MG. CONCLUSIONS These results demonstrate significant chlamydia and MG prevalence in Australian women, and suggest that the differences in strengths of association between numbers of sexual partners and unprotected sex and chlamydia and MG might be due to differences in the transmission dynamics between these infections.This project was funded by the Commonwealth of Australia, as part of a National Chlamydia Pilot program that is currently running to test the effectiveness of a number of models for chlamydia testing in Australia. This project will assist in developing possible recommendations for a National Chlamydia Program. The analysis of MG was funded by the National Health and Research Council (research grant number 509144)

Determinants of mastitis in women in the CASTLE study: a cohort study

BACKGROUND: Mastitis is an acute, debilitating condition that occurs in approximately 20&nbsp;% of breastfeeding women who experience a red, painful breast with fever. This paper describes the factors correlated with mastitis and investigates the presence of Staphylococcus aureus in women who participated in the CASTLE (Candida and Staphylococcus Transmission: Longitudinal Evaluation) study. The CASTLE study was a prospective cohort study which recruited nulliparous women in late pregnancy in two maternity hospitals in Melbourne, Australia in 2009-2011. METHODS: Women completed questionnaires at recruitment and six time-points in the first eight weeks postpartum. Postpartum questionnaires asked about incidences of mastitis, nipple damage, milk supply, expressing practices and breastfeeding problems. Nasal and nipple swabs were collected from mothers and babies, as well as breast milk samples. All samples were cultured for S. aureus. &quot;Time at risk&quot; of mastitis was defined as days between birth and first occurrence of mastitis (for women who developed mastitis) and days between birth and the last study time-point (for women who did not develop mastitis). Risk factors for incidence of mastitis occurring during the time at risk (Incident Rate Ratios [IRR]) were investigated using a discrete version of the multivariable proportional hazards regression model. RESULTS: Twenty percent (70/346) of participants developed mastitis. Women had an increased risk of developing mastitis if they reported nipple damage (IRR 2.17, 95&nbsp;% CI 1.21, 3.91), over-supply of breast milk (IRR 2.60, 95&nbsp;% CI 1.58, 4.29), nipple shield use (IRR 2.93, 95&nbsp;% CI 1.72, 5.01) or expressing several times a day (IRR 1.64, 95&nbsp;% CI 1.01, 2.68). The presence of S. aureus on the nipple (IRR 1.72, 95&nbsp;% CI 1.04, 2.85) or in milk (IRR 1.78, 95&nbsp;% CI 1.08, 2.92) also increased the risk of developing mastitis. CONCLUSIONS: Nipple damage, over-supply of breast milk, use of nipple shields and the presence of S. aureus on the nipple or in breast milk increased the mastitis risk in our prospective cohort study sample. Reducing nipple damage may help reduce maternal breast infections

Does Candida and/or Staphylococcus play a role in nipple and breast pain in lactation? A cohort study in Melbourne, Australia

Objective: To investigate Candida species and Staphylococcus aureus and the development of \u27nipple and breast thrush\u27 among breastfeeding women. Design: Prospective longitudinal cohort study. Setting: Two hospitals in Melbourne, Australia (one public, one private) with follow-up in the community. Participants: 360 nulliparous women recruited at 36 weeks\u27 gestation from November 2009 to June 2011. Participants were followed up six times: in hospital, at home weekly until 4 weeks postpartum and by telephone at 8 weeks. Main outcome measures: Case definition \u27nipple and breast thrush\u27: burning nipple pain and breast pain (not related to mastitis); detection of Candida spp (using culture and PCR) in the mother\u27s vagina, nipple or breast milk or in the baby\u27s mouth; detection of S aureus in the mother\u27 nipple or breast milk. Results: Women with the case definition of nipple/ breast thrush were more likely to have Candida spp in nipple/breast milk/baby oral samples (54%) compared to other women (36%, p=0.014). S aureus was common in nipple/breast milk/baby samples of women with these symptoms as well as women without these symptoms (82% vs 79%) (p=0.597). Time-to-event analysis examined predictors of nipple/breast thrush up to and including the time of data collection. Candida in nipple/breast milk/baby predicted incidence of the case definition (rate ratio (RR) 1.87 (95% CI 1.10 to 3.16, p=0.018). We do not have evidence that S aureus colonisation was a predictor of these symptoms (RR 1.53, 95% CI 0.88 to 2.64, p=0.13). Nipple damage was also a predictor of these symptoms, RR 2.30 (95% CI 1.19 to 4.43, p=0.012). In the multivariate model, with all three predictors, the RRs were very similar to the univariate RRs. This indicates that Candida and nipple damage are independent predictors of our case definition

Sticky Brownian rounding and its applications to constraint satisfaction problems

Semidefinite programming is a powerful tool in the design and analysis of approximation algorithms for combinatorial optimization problems. In particular, the random hyperplane rounding method of Goemans and Williamson [23] has been extensively studied for more than two decades, resulting in various extensions to the original technique and beautiful algorithms for a wide range of applications. Despite the fact that this approach yields tight approximation guarantees for some problems, e.g., Max-Cut, for many others, e.g., Max-SAT and Max-DiCut, the tight approximation ratio is still unknown. One of the main reasons for this is the fact that very few techniques for rounding semidefinite relaxations are known. In this work, we present a new general and simple method for rounding semi-definite programs, based on Brownian motion. Our approach is inspired by recent results in algorithmic discrepancy theory. We develop and present tools for analyzing our new rounding algorithms, utilizing mathematical machinery from the theory of Brownian motion, complex analysis, and partial differential equations. Focusing on constraint satisfaction problems, we apply our method to several classical problems, including Max-Cut, Max-2SAT, and Max-DiCut, and derive new algorithms that are competitive with the best known results. To illustrate the versatility and general applicability of our approach, we give new approximation algorithms for the Max-Cut problem with side constraints that crucially utilizes measure concentration results for the Sticky Brownian Motion, a feature missing from hyperplane rounding and its generalizations

Increasing medicinal and phytochemical compounds of coneflower (Echinacea purpurea L.) as affected by NO3−/NH4+ ratio and perlite particle size in hydroponics

Medicinal plants are considered as one of the most important sources of chemical compounds, so preparing a suitable culture media for medicinal plant growth is a critical factor. The present study is aimed to improve the caffeic acid derivatives and alkylamides percentages of Echinacea purpurea root extract in hydroponic culture media with different perlite particle size and NO3−/NH4+ ratios. Perlite particle size in the growing media was varied as very coarse perlite (more than 2 mm), coarse perlite (1.5–2 mm), medium perlite (1–1.5 mm), fine perlite (0.5–1 mm), and very fine perlite (less than 0.5 mm) in different ratios to peat moss (including pure perlite, 50:50 v/v, 30:70 v/v, and pure peat moss). Two NO3−/NH4+ ratios (90:10 and 70:30) were tested in each growing media. All phytochemical analyses were performed according to standard methods using high performance liquid chromatography (HPLC). It was found that the E. purpurea grown in the medium containing very fine-grade perlite with 50:50 v/v perlite to peat moss ratio had the maximum caffeic acid derivatives, including chicoric acid (17 mg g−1 DW), caftaric acid (6.3 mg g−1 DW), chlorogenic acid (0.93 mg g−1 DW), cynarin (0.84 mg g−1 DW), and echinacoside (0.73 mg g−1 DW), as well as, alkylamides (54.21%). The percentages of these phytochemical compounds increased by decreasing perlite particle size and increasing of NO3−/NH4+ ratio. The major alkylamide in the E. purpurea root extract was dodeca-2E, 4E, 8Z-10 (E/Z)-tetraenoic acid isobutylamide in all treatments, ranging from 31.12 to 54.21% of total dry weight. It can be concluded that optimizing hydroponic culture media and nutrient solution has significant effects on E. purpurea chemical compounds

Metallic Nanoparticles for the Modulation of Tumor Microenvironment; A New Horizon

Cancer is one of the most critical human challenges which endangers many people’s lives every year with enormous direct and indirect costs worldwide. Unfortunately, despite many advanced treatments used in cancer clinics today, the treatments are deficiently encumbered with many side effects often encountered by clinicians while deploying general methods such as chemotherapy, radiotherapy, surgery, or a combination thereof. Due to their low clinical efficacy, numerous side effects, higher economic costs, and relatively poor acceptance by patients, researchers are striving to find better alternatives for treating this life-threatening complication. As a result, Metal nanoparticles (Metal NPs) have been developed for nearly 2 decades due to their important therapeutic properties. Nanoparticles are quite close in size to biological molecules and can easily penetrate into the cell, so one of the goals of nanotechnology is to mount molecules and drugs on nanoparticles and transfer them to the cell. These NPs are effective as multifunctional nanoplatforms for cancer treatment. They have an advantage over routine drugs in delivering anticancer drugs to a specific location. However, targeting cancer sites while performing anti-cancer treatment can be effective in improving the disease and reducing its complications. Among these, the usage of these nanoparticles (NPs) in photodynamic therapy and sonodynamic therapy are notable. Herein, this review is aimed at investigating the effect and appliances of Metal NPs in the modulation tumor microenvironment which bodes well for the utilization of vast and emerging nanomaterial resources