Reproductive biology of the mudskipper Boleophthalmus boddarti in Soc Trang

The mudskipper Boleophthalmus boddarti is an amphibious fish widely distributed in the mudflat regions in Asia, but its reproductive biology was poorly stydied. This study was conducted in the Tran De, Soc Trang, Vietnam, from March 2013 to February 2014, to investigate reproductive parameters of B. boddarti. Data analysis based on a total of 360 collected fish (188 females and 172 males) suggest that the sex ratio of this mudskipper was not significantly different between dry and wet seasons. This fish was a multiple reproducer and spawned in the wet season with a peak spawning in three main months of this season (August to October) as difference stages of oocytes were observed in the ovaries. The male B. boddarti released sperms during the reproductive season since different type of spermatogonia were found in stage V testis sections. This fish reached 11.52 cm total length at first sex maturation and was high fecundity (9,800-33,800 eggs), indicating a possible adaptation of this species to the monsoonal climate. The understanding of the reproductive biology of B. boddarti provides useful knowledge of its reproductive adaptation to the mudflat toward sustainable management in the study region

Winter Activity and Diapause of Aedes albopictus(Diptera: Culicidae) in Hanoi, Northern Vietnam

We studied the winter activity of Aedes albopictus (Skuse) from November 2008 to April 2009 in Bat Trang village of Hanoi, Vietnam. We selected 12 houses and collected: 1) adults with BG sentinel traps, 2) pupae from household water containers, and 3) eggs with ovitraps. Aedes albopictus adults, pupae, and eggs were not collected from early January to early February. Though the egg hatching probability tended to be initially high at longer day length, the maximum probability gradually shifted to shorter day length, as the observation period elapsed. When females were reared under long day length and their eggs were immersed 1 or 5 wk after oviposition, >50% of eggs hatched within 20 days. However, when females were reared under short day length and their eggs were immersed after 1 wk, hatching was suppressed for 60 days. When females were reared under short day length, the median hatching day occurred earlier in eggs kept dry for 5 and 10 wk after oviposition than in those dried for only 1 wk. This indicates that the extended dry periods accelerate egg hatching. Our results showed that hatchability gradually changed with day length, suggesting that selection for overwintering is not as strong relative to Ae. albopictus living in the temperate zone, where winter conditions are less favorable than in tropical and subtropical areas

Accounting reform and value relevance of financial reporting from non-financial listed firms on the Vietnam stock market

AbstractThe research questions that are solved in this paper are as follows: (1) how the value relevance of accounting information evolved from a developing country perspective and (2) how the accounting reform impacts on value relevance. This study aims to assess the value relevance of accounting information released by non-financial firms listed on the Vietnam stock exchange for the period of 2010–2020. Our paper will contribute more supportive empirical evidence about the usefulness of value relevance research through doing research in Vietnam as a developing country, where experiences switching from a planned economy to an open economy and the regulations change continuously. We provide useful literature overview and important implications for both equity investors and standard setters. Based on usefulness information theory and asymmetric information theory, research hypotheses are designed. The study then uses the Ohlson price model to test these hypotheses. In the model, the explanatory variables, namely, book value per share, earnings per share, and share prices as independent variable, are examined; panel corrected standard error estimator (PCSE) is applied. The findings reveal that both earnings and book value of equity exhibit a positive and significant effect on stock prices. Earnings explain the higher variation in stock market values on the Vietnam Stock Exchange compared to book value of equity. The study, however, finds a decreasing trend in the change of the value relevance over the period 2010–2020 and accounting reforms in 2014 did not improve the value relevance

IOTA simple rules: An efficient tool for evaluation of ovarian tumors by non-experienced but trained examiners - A prospective study

Objectives: A simple and efficient tool for evaluating ovarian tumors in general hospitals where radiologists without experience in gynecological ultrasound is necessary. This study aims to evaluate the diagnostic performance of IOTA simple rules in initial classification of ovarian tumors by non-experienced examiners who have received simple training. Materials and method: A prospective single-center study was conducted at Hanoi Obstetrics and Gynecology Hospital. Three resident gynecologists trained themselves for two weeks and then received hands-on practice under the supervision of experts for another two weeks. The examiners performed ultrasound on 424 eligible women scheduled for surgery for ovarian tumors and classified the tumors based on IOTA simple rules. The postoperative pathology of ovarian tumors was used as the gold standard. Results: 90.8 % (385/424) of the tumors were benign. Simple rules were applicable in 399/424 (94.1 %) tumors, with a sensitivity of 84.8 % (95 % CI, 70.2–94.3), specificity of 98.9 % (95 % CI, 97.5–99.7), positive predictive value of 87.5 % (95 % CI, 73.3–95.9), and negative predictive value of 98.6 % (95 % CI, 97.1–99.5). The sensitivity of IOTA simple rules was higher in postmenopausal women (91.7 % vs. 81.0 %), while the specificity was higher in premenopausal women (99.4 % vs. 95.8 %). Accuracy was 100 % in all ten pregnant women were assessed using these rules. Conclusion: In conclusion, in the hands of non-expert examiners who were trained thoroughly, IOTA simple rules are a simple and efficient tool for clinical practice in centers where expert radiologists in gynecology are not always available. The training program is simple and could be applied widely in other clinical centers. Further studies are necessary to evaluate the effectiveness of the IOTA simple rules in assessing ovarian tumors among pregnant women

Deep Learning Application in Dental Caries Detection Using Intraoral Photos Taken by Smartphones

A mobile-phone-based diagnostic tool, which most of the population can easily access, could be a game changer in increasing the number of examinations of people with dental caries. This study aimed to apply a deep learning algorithm in diagnosing the stages of smooth surface caries via smartphone images. Materials and methods: A training dataset consisting of 1902 photos of the smooth surface of teeth taken with an iPhone 7 from 695 people was used. Four deep learning models, consisting of Faster Region-Based Convolutional Neural Networks (Faster R-CNNs), You Only Look Once version 3 (YOLOv3), RetinaNet, and Single-Shot Multi-Box Detector (SSD), were tested to detect initial caries lesions and cavities. The reference standard was the diagnosis of a dentist based on image examination according to the International Caries Classification and Management System (ICCMS) classification. Results: For cavitated caries, YOLOv3 and Faster R-CNN showed the highest sensitivity among the four tested models, at 87.4% and 71.4%, respectively. The sensitivity levels of these two models were only 36.9 % and 26% for visually non-cavitated (VNC). The specificity of the four models reached above 86% for cavitated caries and above 71% for VNC. Conclusion: The clinical application of YOLOv3 and Faster R-CNN models for diagnosing dental caries via smartphone images was promising. The current study provides a preliminary insight into the potential translation of AI from the laboratory to clinical practice

Deep Learning Application in Dental Caries Detection Using Intraoral Photos Taken by Smartphones

A mobile-phone-based diagnostic tool, which most of the population can easily access, could be a game changer in increasing the number of examinations of people with dental caries. This study aimed to apply a deep learning algorithm in diagnosing the stages of smooth surface caries via smartphone images. Materials and methods: A training dataset consisting of 1902 photos of the smooth surface of teeth taken with an iPhone 7 from 695 people was used. Four deep learning models, consisting of Faster Region-Based Convolutional Neural Networks (Faster R-CNNs), You Only Look Once version 3 (YOLOv3), RetinaNet, and Single-Shot Multi-Box Detector (SSD), were tested to detect initial caries lesions and cavities. The reference standard was the diagnosis of a dentist based on image examination according to the International Caries Classification and Management System (ICCMS) classification. Results: For cavitated caries, YOLOv3 and Faster R-CNN showed the highest sensitivity among the four tested models, at 87.4% and 71.4%, respectively. The sensitivity levels of these two models were only 36.9 % and 26% for visually non-cavitated (VNC). The specificity of the four models reached above 86% for cavitated caries and above 71% for VNC. Conclusion: The clinical application of YOLOv3 and Faster R-CNN models for diagnosing dental caries via smartphone images was promising. The current study provides a preliminary insight into the potential translation of AI from the laboratory to clinical practice

Diagnostic Value of Fluorescence Methods, Visual Inspection and Photographic Visual Examination in Initial Caries Lesion: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to investigate the efficacy of fluorescence-based methods, visual inspections, and photographic visual examinations in initial caries detection. A literature search was undertaken in the PubMed and Cochrane databases. Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines were followed, and eligible articles published from 1 January 2009 to 30 October 2019 were included if they met the following criteria: they (1) assessed the accuracy of methods of detecting initial tooth caries lesions on occlusal, proximal, or smooth surfaces in both primary and permanent teeth (in clinical); (2) used a reference standard; (3) reported data regarding the sample size, prevalence of initial tooth caries, and accuracy of the methods. Data collection and extraction, quality assessment, and data analysis were conducted according to Cochrane standards Quality Assessment of Diagnostic Accuracy Studies-2. Statistical analyses were performed using Review Manager 5.3 and STATA 14.0. A total of 12 eligible articles were included in the meta-analysis. The results showed that the sensitivity and specificity of fluorescence-based methods were 80% and 80%, respectively; visual inspection was measured at 80% and 75%, respectively; photographic visual examination was measured at 67% and 79%, respectively. We found that the visual method and the fluorescence method were reliable for laboratory use to detect early-stage caries with equivalent accuracy

Diagnostic Value of Fluorescence Methods, Visual Inspection and Photographic Visual Examination in Initial Caries Lesion: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to investigate the efficacy of fluorescence-based methods, visual inspections, and photographic visual examinations in initial caries detection. A literature search was undertaken in the PubMed and Cochrane databases. Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines were followed, and eligible articles published from 1 January 2009 to 30 October 2019 were included if they met the following criteria: they (1) assessed the accuracy of methods of detecting initial tooth caries lesions on occlusal, proximal, or smooth surfaces in both primary and permanent teeth (in clinical); (2) used a reference standard; (3) reported data regarding the sample size, prevalence of initial tooth caries, and accuracy of the methods. Data collection and extraction, quality assessment, and data analysis were conducted according to Cochrane standards Quality Assessment of Diagnostic Accuracy Studies-2. Statistical analyses were performed using Review Manager 5.3 and STATA 14.0. A total of 12 eligible articles were included in the meta-analysis. The results showed that the sensitivity and specificity of fluorescence-based methods were 80% and 80%, respectively; visual inspection was measured at 80% and 75%, respectively; photographic visual examination was measured at 67% and 79%, respectively. We found that the visual method and the fluorescence method were reliable for laboratory use to detect early-stage caries with equivalent accuracy

Fatty Acid, Lipid Classes and Phospholipid Molecular Species Composition of the Marine Clam Meretrix lyrata (Sowerby 1851) from Cua Lo Beach, Nghe An Province, Vietnam

This study aims to analyze compositions of fatty acids and phospholipid molecular species in the hard clams Meretrix lyrata (Sowerby, 1851) harvested from Cua Lo beach, Nghe An province, Viet Nam. Total lipid of hard clams Meretrix lyrata occupied 1.7 ± 0.2% of wet weight and contained six classes: hydrocarbon and wax (HW), triacylglycerol (TAG), free fatty acids (FFA), sterol (ST), polar lipid (PoL), and monoalkyl diacylglycerol (MADAG). Among the constituents, the proportion of PoL accounted was highest, at 45.7%. In contrast, the figures for MADAG were lowest, at 1.3%. Twenty-six fatty acids were identified with the ratios of USAFA/SAFA was 2. The percentage of n-3 PUFA (ω-3) and n-6 PUFA (ω-6) was high, occupying 38.4% of total FA. Among PUFAs, arachidonic acid (AA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid (DPA, 22:5n-3), and docosahexaenoic acid (DHA, 22:6n-3) accounted for 3.8%, 7.8%, 2.2% and 12.0% of total lipid of the clam respectively. Phospholipid molecular species were identified in polar lipids of the clams consisting six types: phosphatidylethalnolamine (PE, with 28 molecular species), phosphatidylcholine (PC, with 26 molecular species), phosphatidylserine (PS, with 18 molecular species), phosphatidylinositol (PI, with 10 molecular species), phosphatidylglycerol (PG, with only one molecular species), and ceramide aminoethylphosphonate (CAEP, with 15 molecular species). This is the first time that the molecular species of sphingophospholipid were determined, in Meretrix lyrata in particular, and for clams in general. Phospholipid formula species of PE and PS were revealed to comprise two kinds: Alkenyl acyl glycerophosphoethanolamine and Alkenyl acyl glycerophosphoserine occupy 80.3% and 81.0% of total PE and PS species, respectively. In contrast, the percentage of diacyl glycero phosphatidylcholine was twice as high as that of PakCho in total PC, at 69.3, in comparison with 30.7%. In addition, phospholipid formula species of PI and PG comprised only diacyl glycoro phospholipids. PE 36:1 (p18:0/18:1), PC 38:6 (16:0/22:6), PS 38:1 (p18:0/20:1), PI 40:5 (20:1/20:4), PG 32:0 (16:0/16:0) and CAEP 34:2 (16:2/d18:0) were the major molecular species