Dermoscopic dark corner artifacts removal: Friend or foe?

Background and Objectives: One of the more significant obstacles in classification of skin cancer is the presence of artifacts. This paper investigates the effect of dark corner artifacts, which result from the use of dermoscopes, on the performance of a deep learning binary classification task. Previous research attempted to remove and inpaint dark corner artifacts, with the intention of creating an ideal condition for models. However, such research has been shown to be inconclusive due to a lack of available datasets with corresponding labels for dark corner artifact cases. Methods: To address these issues, we label 10,250 skin lesion images from publicly available datasets and introduce a balanced dataset with an equal number of melanoma and non-melanoma cases. The training set comprises 6126 images without artifacts, and the testing set comprises 4124 images with dark corner artifacts. We conduct three experiments to provide new understanding on the effects of dark corner artifacts, including inpainted and synthetically generated examples, on a deep learning method. Results: Our results suggest that introducing synthetic dark corner artifacts which have been superimposed onto the training set improved model performance, particularly in terms of the true negative rate. This indicates that deep learning learnt to ignore dark corner artifacts, rather than treating it as melanoma, when dark corner artifacts were introduced into the training set. Further, we propose a new approach to quantifying heatmaps indicating network focus using a root mean square measure of the brightness intensity in the different regions of the heatmaps. Conclusions: The proposed artifact methods can be used in future experiments to help alleviate possible impacts on model performance. Additionally, the newly proposed heatmap quantification analysis will help to better understand the relationships between heatmap results and other model performance metrics

Optimizing electrode implantation in sacral nerve stimulation—an anatomical cadaver study controlled by a laparoscopic camera

Background and aim: Sacral nerve stimulation is the therapy of choice in patients with neurogenic faecal and urine incontinence, constipation and some pelvic pain syndromes. The aim of this study is to determine the best insertion angles of the electrode under laparoscopic visualization of the sacral nerves. Materials and methods: Five fresh cadaver pelvises were dissected through an anterior approach of the presacral space, exposing the ventral sacral roots. Needles and electrodes were inserted into the S3 foramen. Both right and left sides were used, with the traditional percutaneous procedure. The validation was done by a laparoscopic camera controlling the position of the needle and electrode on the nerve. The angles were assessed with a goniometer and were confirmed in two living patients. Results: The mean angle of insertion in the sagittal plane was 62.9 ± 3° (range, 59-70). In the axial plane, the mean angle for the left side was 91.7 ± 13.5° (range, 80-110) and 83.2 ± 7.7° for the right side (range, 75-95). These angles resulted in the optimal placement of the leads along the S3 sacral root, in all these cases. Conclusions: This study allows direct visualization during the placement of the needle and electrode, thus permitting accurate calculations of the best angle of approach during the surgical procedure in sacral nerve stimulation. These objective findings attempt to standardize this technique, which is often performed with the aid of intra-operative fluoroscopy but still leaving a lot to chance. These insertion angles should help to find more consistent and reproducible results and thus improved outcome in patient

Patterns of RAPD markers and heavy metal concentrations in Perna viridis (L.), collected from metal-contaminated and uncontaminated coastal waters: Are they correlated with each other?

Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique, namely Random Amplified Polymorphic DNA (RAPD), to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb, and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA based on the RAPD markers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian, and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution

Forced Stratified Turbulence: Successive Transitions with Reynolds Number

Numerical simulations are made for forced turbulence at a sequence of increasing values of Reynolds number, R, keeping fixed a strongly stable, volume-mean density stratification. At smaller values of R, the turbulent velocity is mainly horizontal, and the momentum balance is approximately cyclostrophic and hydrostatic. This is a regime dominated by so-called pancake vortices, with only a weak excitation of internal gravity waves and large values of the local Richardson number, Ri, everywhere. At higher values of R there are successive transitions to (a) overturning motions with local reversals in the density stratification and small or negative values of Ri; (b) growth of a horizontally uniform vertical shear flow component; and (c) growth of a large-scale vertical flow component. Throughout these transitions, pancake vortices continue to dominate the large-scale part of the turbulence, and the gravity wave component remains weak except at small scales.Comment: 8 pages, 5 figures (submitted to Phys. Rev. E

Effects of Different Drying Methods on Extractable Phenolic Compounds from Turkey Berry (Solanum torvum) Leaves

In the Philippines, there is an abundance of plants rich in phenolic compounds such as Solanum torvum (turkey berry), a plant with antifungal, antibacterial, anticancer, antimicrobial, and antiviral properties; however, there is not much information on the extraction of its phenolics, especially on the best drying method that will give the highest yield. Drying reduces water which allows better extraction of the said phenolics, but different drying methods expose the phenolics to possible degradation. In this study, the effect of different drying methods, namely sun-drying, freeze-drying, and microwave-drying on the extraction of total phenolics from S. torvum leaves was investigated. The dried leaves were macerated to determine the best drying method that would give the highest content of phenolic compounds from S. torvum leaves. Sun-drying, the most energy-efficient method, resulted in the highest extraction yield of 2.14 ± 0.01 mg GAE/g d.w., which was significantly different from the yields of microwave-drying and freeze-drying. Freeze-drying resulted in the lowest yield of 1.02 ± 0.01 mg GAE/g d.w., while microwave-drying yielded 1.58 ± 0.03 mg GAE/g d.w. Due to the photosensitivity of the freeze-dried samples and the high temperature of microwave-drying, phenolic compounds have degraded resulting in lesser yields. Although microwave-drying yielded less than sun-drying, it is the most efficient drying method out of the three as it is more energy-efficient than freeze-drying and less time-consuming than the others

DETERMINANTS OF ENERGY CONSUMPTION: A REVIEW OF THE PHILIPPINE ENERGY SECTOR

Energy is considered a vital component of economic growth and human development. When its availability is disrupted, several economic sectors could not function fully to its extent. Energy consumption is influenced by several variables that affect it directly or indirectly. This study was conducted to evaluate the impact of GDP, industrialization, urbanization, trade openness, financial development, and FDI on the energy consumption of the Philippines; and to present the trend of each variable from 1971 to 2014. Data on energy consumption, GDP, industrialization, urbanization, trade openness, financial development, and FDI of the Philippines from 1971 to 2014 were sourced from the World Development Indicators published by the World Bank. The Ordinary Least Squares (OLS) regression analysis was used to analyze and identify those factors that significantly affect the energy consumption of the Philippines. Results indicated that GDP, industrialization, urbanization, and financial development significantly affect the energy consumption of the Philippines. These determinants have p-values that are lower than the 5% significance level. Thus, this study provides the policy and decision-makers with ample information for decisive decision-making in the Philippine energy sector.  Article visualizations

Thomas Decomposition of Algebraic and Differential Systems

In this paper we consider disjoint decomposition of algebraic and non-linear partial differential systems of equations and inequations into so-called simple subsystems. We exploit Thomas decomposition ideas and develop them into a new algorithm. For algebraic systems simplicity means triangularity, squarefreeness and non-vanishing initials. For differential systems the algorithm provides not only algebraic simplicity but also involutivity. The algorithm has been implemented in Maple

Hormone Replacement Therapy and Dry Eye in Post Menopausal Women: Study in a Tertiary Centre in Malaysia

Background: Menopause involves decrease in the body estrogen level. There are many disorders associated with estrogen deficiency state. Postmenopausal women frequently report dry eye symptoms due to the decrease in the level of circulating estrogen hormone. Hormone replacement therapy (HRT) is given to alleviate some of the menopausal effects. This study aimed to compare the tear production between postmenopausal women treated with or without HRT.Methods: This cross-sectional study was performed on 140 participants attending various clinics in Universiti Kebangsaan Malaysia Medical Centre (UKMMC) namely the obstetric and gynecology, Surgery, Orthopedic and Otorhinolaryngology clinics over a period of 3 months. The subjects were either with or without HRT. Schirmer’s Test strip was used to measure the tear quantity. Dry eye was defined when the length of the moistened area on the strip is less than 5 mm.Results: The results showed significant difference in tear quantity in postmenopausal women treated with or without HRT (p=0.003). No correlation was observed between tear quantity and duration of HRT consumption (p=0.217). No significant correlation was also found between the tear quantity and duration of menopause (p=0.150).Conclusions: Our results suggested that HRT helps in improving tear production in postmenopausal women regardless of the duration of HRT consumption or menopause. However, duration of HRT consumption or menopause exert no significant effect on the tear quantity