Search

Background Purpose Methods Results Conclusions Recently, high‐dose‐rate (HDR) brachytherapy treatment plans generation was improved with the development of multicriteria optimization (MCO) algorithms that can generate thousands of pareto optimal plans within seconds. This brings a shift, from the objective of generating an acceptable plan to choosing the best plans out of thousands.In order to choose the best plans, new criteria beyond usual dosimetrics volumes histogram (DVH) metrics are introduced and a deep learning (DL) framework is added as an automatic plan selection algorithm.The new criteria are visual‐like criteria implemented for the bladder, rectum, and urethra. One criterion also takes into account the cold spot in the prostate. Those criteria, along with commonly used DVH criteria, are used to form classes on which to train the algorithm. The algorithm is trained with an input of two 3D images, dose and mask of the anatomy, in order to rank and automatically select a plan. The confidence in the output is used for ranking and the automatic plan selection. The algorithm is trained on 835 previously treated prostate cancer patients and evaluated on a separated 20 patients cohort previously evaluated by two experts (clinical medical physicists) in an inter‐observer MCO study.The deep network takes 10 s to rank 2000 plans (vs. 5–10 min for experts to rank 4 preferred plans). A total of four different networks are trained which offer different trade‐offs. The key trade‐offs are the target coverage or the organs at risk (OAR) sparing. The algorithm with the best network achieves no statistical difference with the plans chosen by the two experts for 6 and 9 criteria, respectively, out of 13 criteria (paired t‐test with p >$>$ 0.05) while the two experts have no statistical difference between them for 7 criteria.The developed approach is flexible since it allows the modification or addition of criteria to obtain different trade‐offs in plan quality, per the institution standard. The approach is fast and robust while adding negligible time to MCO planning. These results demonstrate potential for clinical use. [ABSTRACT FROM AUTHOR]

This study assesses the dosimetric effectiveness of the commercial trade-off optimization (TO) module in comparison to iterative optimization for volumetric modulated arc therapy (VMAT) in craniospinal irradiation technique.Fifteen patients who had previously undergone VMAT-based craniospinal irradiation (CSI) using manual optimization (TP) underwent re-optimization with trade-off optimization (MCO). All patients were treated using the Halcyon-E O-ring linear accelerator, with maximum field size of 28×28 cm², a 6MV unflattened beam, and adjacent isocenter field overlap of 10 cm. Plans were compared based on PTV dose coverage (D95%), maximum dose (Dmax), conformity index (CI), heterogeneity index (HI), maximum and mean dose to serial and parallel organs, respectively. Statistical evaluation was conducted using paired sample t-tests. The PTVD95% for TO and MCO plans were 98.0% ± 1.0% and 97.4% ± 0.7%, respectively. In the same sequence, HIs were 1.06 ± 0.01 and 1.07 ± 0.01. CIs for both arms were 0.9 ± 0.0 and its variation was statistically significant (p = 0.027). The differences in dose for bilateral cochlea and left optic nerves were statistically significant (0.022≤ p ≤0.049). The ΔDmax for serial organs and mean dose for parallel organs did not exceed 1%, except for the bilateral optic nerve, mandible, oral cavity, right parotid, and stomach. No parallel organ showed a statistically significant dose variation. Clinically significant reductions in dose were noted for three organs; the average dose reduction in MCO plans for bilateral optic nerves was 3.9%, and for the larynx, it was 8.5%. In this study, trade-off optimization did not demonstrate any significant improvement over the iteratively optimized plans, primarily because the planners were highly skilled and could already generate high-quality plans using iterative optimization alone. However, this finding may not necessarily apply universally to all treatment planners or clinical settings. [ABSTRACT FROM AUTHOR]

IntroductionThe objective of this study is to evaluate the performance of an automatic workflow for head-and-neck (H&N) radiotherapy using a multi-atlas based auto-contouring software and an a-priori multicriteria plan optimization algorithm and implement an adaptive online approach with CBCT images. Two different modalities are investigated, the fluence-to-position (FTP) and the adapt-to-shape (ATS) approach.Materials and methodsNine patients are used for the multi-atlas database. The organs at risk (OARs) of the H&N district and five additional structures (air, fat, tissue, bone and patient’s exterior) subsequently used for the creation of the synthetic CT are auto-contoured with the Elekta ADMIRE® software. The mCycle algorithm is used for the a-priori multicriteria plan calculation. A total of twenty H&N patients are selected for this step. The automatic plans are compared to manual VMAT plans by assessing differences in planning time, dose delivered to targets and OARs, and calculating the plan quality indexes (PQIs). Two patients are chosen for the retrospective CBCT adaptive online feasibility analysis. To assess the differences for the two adaptive modalities, the clinical goals for targets and OARs and the number of passed constraints are explored. An analysis of the timing for the different steps is carried out to assess its clinical applicability.ResultThe dice of the five HU layer structures range between 0.66 and 0.99. The mCycle auto-planning significantly reduces planning time, from 2 hours to 10 minutes. The radiotherapist deems all plans clinically acceptable, and in the majority of cases the automatic plan is the preference choice. The automatic plans enhance OARs sparing and preserve a good target coverage, this is also confirmed by the PQIs result. Comparing FTP and ATS modes in adaptive radiotherapy, ATS exhibits superior outcomes, mostly in the target coverage. In the FTP techniques target coverage is inadequate and statistically different from the accepted values. In the ATS the results align with the initial approved values. Using the ATS mode the planning time takes around 14 minutes and approximately 20 minutes for the entire treatment.ConclusionThis study contributes to the advancement of automatic and adaptive radiotherapy, demonstrating the potential of an automated workflow in H&N treatments.

Copyright of Small Business International Review is the property of Asociacion Espanola de Contabilidad y Administracion de Empresas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The authors investigated posttraumatic stress disorder (PTSD), anxiety, and depressive symptoms among university students in Malaysia during the COVID-19 pandemic lockdown in a cross-sectional study involving 375 students. Results showed that 39.5% reported PTSD symptoms, 37.3% anxiety symptoms, and 51.4% depressive symptoms. PTSD is significantly correlated with anxiety and depressive symptoms. Female students reported significantly higher PTSD and depressive symptoms. There was a significant association between race, PTSD, and anxiety symptoms. Participants who stayed at residential college (46.2%) and had underlying health problems (70%) reported having significant anxiety symptoms. A significant association between ethnicity and depressive symptoms and underlying health status was also found. The high rates of PTSD, anxiety, and depressive symptoms call for action for mental health promotion and improving mental health delivery services to higher education students in the wake of COVID-19. [ABSTRACT FROM AUTHOR]

Purpose: A new development on the RayStation treatment planning system (TPS) allows a plan to be planned by imposing a constraint on the leaf sequencing: all leaves move in the same direction before moving again in the opposite direction to create a succession of sliding windows (SWs). The study aims to investigate this new leaf sequencing, coupled with standard optimization (SO) and multi‐criteria optimization (MCO) and to compare it with the standard sequencing (STD). Methods: Sixty plans were replanned for 10 head and neck cancer patients (two dose levels simultaneously SIB, 56 and 70 Gy in 35 fractions). All plans were compared, and a Wilcoxon signed‐rank test was performed. Pre‐processing QA and metrics of multileaf collimator (MLC) complexity were studied. Results: All methodologies met the dose requirements for the planning target volumes (PTVs) and organs at risk (OARs). SO demonstrates significantly best results for homogeneity index (HI), conformity index (CI), and target coverage (TC). SO‐SW gives best results for PTVs (D98% and D2%) but the differences between techniques are less than 1%. Only the D2%,PTV‐56 Gy is higher with both MCO methods. MCO‐STD offer the best sparing OARs (parotids, spinal cord, larynx, oral cavity). The gamma passing rates (GPRs) with 3%/3 mm criteria between the measured and calculated dose distributions are higher than 95%, slightly lowest with SW. The number of monitor units (MUs) and MLC metrics are higher in SW show a higher modulation. Conclusions: All plans are feasible for the treatment. A clear advantage of SO‐SW is that the treatment plan is more straightforward to planning by the user due to the more advanced modulation. MCO stands out for its ease of use and will allow a less experienced user to offer a better plan than in SO. In addition, MCO‐STD will reduce the dose to the OARs while maintaining good TC. [ABSTRACT FROM AUTHOR]

Precise outpatient volume prediction holds significant importance in hospital management. While the Gated Recurrent Unit (GRU) is a frequently utilized deep learning technique for forecasting hospital outpatient volumes, creating a proficient GRU model necessitates the fine-tuning of pertinent GRU parameters. The adjustment of suchparameters relies heavily on an individual’s practical experience and prior knowledge. The recently proposed Cheetah optimizer is a novel intelligent algorithm with unique optimization capabilities. The Cheetah optimizer holds significant research potential; however, additional investigations are warranted, as it may be vulnerable to issues related to local optimization. In the present study, the selection of hyperparameters for the GRU model was optimized through the utilization of the Modified Cheetah Optimization (MCO) algorithm, and a combined MCO-GRU model was established. Using the Successive Variational Mode Decomposition (SVMD) method to decompose outpatient volume sample data, the parameters of the GRU model were optimized with the MCO method to construct a hybrid forecasting model. This yielded the smallest Root Mean Square Error (RMSE) for the proposed model, with a value of 0.0843. Additionally, the results indicate that in comparison to SVMD, Long Short-Term Memory (LSTM), GRU, Particle Swarm Optimization-GRU (PSO-GRU), and Cheetah Optimization-GRU (CO-GRU), the proposed model significantly enhanced the accuracy of outpatient volume forecasting.

This study aimed to classify the spatiotemporal analysis of rainwater quality before and during the Movement Control Order (MCO) implementation due to the COVID-19 pandemic. Chemometric analysis was carried out on rainwater samples collected from 24-gauge stations throughout Malaysia to determine the samples' chemical content, pH, and conductivity. Other than that, hierarchical agglomerative cluster analysis (HACA) and discriminant analysis (DA) were used to classify the quality of rainwater at each location into four clusters, namely good, satisfactory, moderate, and bad clusters. Note that DA was carried out on the predefined clusters. The reduction in acidity levels occurred in 11 stations (46% of overall stations) after the MCO was implemented. Chemical content and ion abundance followed a downward trend, indicating that Cl− and Na+ were the most dominant among the anions and cations. Apart from that, NH4+, Ca2+, NO3−, and SO42− concentrations were evident in areas with significant anthropogenic activity, as there was a difference in the total chemical content in rainwater when compared before and during the MCO. Based on the dataset before the MCO, 75% of gauge stations were in the good cluster, 8.3% in the satisfactory cluster, 12.5% in the moderate cluster, and 4.2% in the bad cluster. Meanwhile, the dataset during the MCO shows that 72.7% of gauge stations were in the good cluster, 9.1% in the satisfactory cluster, 9.1% in the moderate, and 4.5% in the bad cluster. From this study, the chemometric analysis of the year 2020 rainwater chemical composite dataset strongly indicates that reduction of human activities during MCO affected the quality of rainwater. [ABSTRACT FROM AUTHOR]

The COVID-19 cases have taken its strike since December 2019 in Wuhan, China and then has spread to other countries. Malaysia was not excluded from this pandemic, in which the first case of COVID-19 was discovered on 25th January 2020. The disease has caused a pandemic outbreak ever since, driving many countries to close international gateways and implement lockdowns and many studies have been trying to model and forecast the rising number of Covid-19 cases worldwide. This study aimed to prove the effectiveness of Movement Control Order (MCO) phases implemented in Malaysia. From 8 MCO phases implemented in Malaysia, 5 of the MCO phases were taken into consideration for this study. Line plots were used to observed the pattern, increasing (+) or decreasing (-) number of cases for each MCO implementation. The before and after trends for each phase were recorded and tabulated. Using the Wilcoxon Signed-rank test with Binomial probability calculation showed the p-value=0.001< α=0.05 obtained. Hence, supported the hypothesis that MCO implementation reduces the number of positive cases in Malaysia. In conclusion, the implementation of lockdown would ‘flatten the curve’ of the daily COVID-19 cases, resulting in better control over the spread of the COVID-19 virus in Malaysia.

Los estudios de participación cultural tienden a concentrar su enfoque en el análisis de las variables socioeconómicas o la disponibilidad de infraestructuras, dejando en un segundo plano variables de carácter idiosincrático como el interés manifestado o la predisposición a participar. Empleando los datos de la Encuesta de Hábitos y Prácticas Culturales de España 2018-2019, y mediante la modelización con mínimos cuadrados ordinarios (MCO), se busca estudiar los pesos de las variables socioeconómicas clásicas, así como las diferentes variables que componen el capital cultural dado su carácter aditivo en el desarrollo del interés. Los principales resultados obtenidos presentan al capital cultural como el componente más determinante en la formación del interés, siendo la lectura en la infancia la que presenta el mayor impacto. Destaca también la posible existencia de transferencia intergeneracional del interés, al presentar un mayor peso entre las variables la participación de los padres que la del propio sujeto durante la infancia.

Cet article examine les déterminants du chômage en RDC. Le caractère réduit de l’échantillon, à savoir un pays, et cela s’explique par la disponibilité des données portant sur la période 2001-2020. Le modèle inspiré de la littérature empirique est estimé par la méthode des moindres carrés ordinaires (OLS). Nos résultats économétriques révèlent que les variables éducation, l’inflation, l’investissement direct à l’étranger, la population explique significativement le niveau de chômage des jeunes au seuil d’un 1% et de 5 %. L’éducation et les investissements directs à l’étranger tendent à augmenter le taux de chômage tandis que la croissance de la population et l’inflation tendent à réduire le taux de chômage.

Due to the COVID-19 pandemic, many countries have implemented movement control orders (MCO). Globally, including in Malaysia, such bans have reduced pollution. Thus, this study used remote sensing to examine the particle dispersion and intensity of PM10. Unlike previous research, this technique used Landsat 8 Operational Land Imager (OLI) satellite images to estimate anthropogenic level changes within the study area. Eight models are used to estimate PM10 levels. The models work well because they were developed and tested in India, which has a similar climate to Malaysia. Two models returned results that matched the study area's CAQMs station. Between 10th March 2020 and 26th March 2020 the CAQMS showed an average PM10 concentration of 17-32 g/m3 . The pixel based PM10 estimation is 30-35% off in g/m3 . However, the percent reduction of PM10 before and during MCO was within 2% of Model 5 and 7. Incorporating geospatial technology into baseline studies to assess current air quality is clearly beneficial. Since the first MCO in March 2020, toxic pollution emissions have decreased significantly.

Mining activities in the Chini Lake catchment area have been extensive for several years, contributing to acid mine drainage (AMD) events with high concentrations of iron (Fe) and other heavy metals impacting the surface water. However, during the restriction period due to the COVID-19 outbreak, anthropogenic activities have been suspended, which clearly shows a good opportunity for a better environment. Therefore, we aimed to analyze the variation of AMD-associated water pollution in three main zones of the Chini Lake catchment area using Sentinel-2 data for the periods pre-movement control order (MCO), during MCO, and post-MCO from 2019 to 2021. These three zones were chosen due to their proximity to mining areas: zone 1 in the northeastern part, zone 2 in the southeastern part, and zone 3 in the southern part of the Chini Lake area. The acid mine water index (AMWI) was a specific index used to estimate acid mine water. The AMWI values from Sentinel-2 images exhibited that the mean AMWI values in all zones during the MCO period decreased by 14% compared with the pre-MCO period. The spatiotemporal analysis found that the highest polluted zones were recorded in zone 1, followed by zone 3 and zone 2. As compared with during the MCO period, the maximum percentage of increment during post-MCO in all zones was up to 25%. The loosened restriction policy has resulted in more AMD flowing into surface water and increased pollution in Chini Lake. As a whole, our outputs revealed that Sentinel-2 data had a major potential for assessing the AMD-associated pollution of water. [ABSTRACT FROM AUTHOR]

"Man is born free, but he is everywhere in chains." This famous phrase made by Geneva-born political philosopher, Jean-Jacques Rousseau back in 1762 is one especially relevant in this COVID-19 era of today where individuals have severely been restricted in their movements since the start of the pandemic in early 2020. In Malaysia, applications such as MySejahtera further enable the government to track and limit the movements of citizens whilst simultaneously issuing them warnings in events of breaches to restrictions posed by the government. In light of mass protests of citizens from the likes of Austria, Australia, the United States, France, Italy, the Netherlands and other liberal democracies, 2 a rather compelling question can be raised. Does the necessity of collective safety outweigh the rights of individual privacy and freedom? This is a question which has been at the forefront of the minds of governments and authorities in establishing standard operating procedures, rules and regulations for which there appears to be no concrete answer. In this text, we have approached the views from various schools of jurists in restricting the right of movements in Malaysia during the Movement Control Order (MCO), declared by the government in order to curb the spread of the coronavirus. A discussion is done on the necessity of tightening the basic human rights in favour of gaining collective safety in the context of jurisprudence. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 pandemic has negatively impacted the eating behaviours of people especially fruits and vegetable intake. No study has addressed the fruits and vegetables intake during the COVID-19 in Malaysia. Aim: to assess the daily intake of fruits and vegetables among Malaysian adults during the COVID-19 outbreak, perceived changes in intake, as well as factors associated with the changes in intake. Methods: A cross-sectional study was conducted through online platforms and a total of 506 participants were recruited. Semi food-frequency questionnaires were used to assess participants' fruit and vegetable intake. Socio-demographics information, knowledge, attitude and practices (KAP) of fruits and vegetables were collected. All statistical analyses were performed using SPSS. Results: The majority of participants (99.8%) did not achieve the recommended five servings per day, in which they consumed an average of 0.84 servings of fruits and vegetables per day. 46.4% of participants reported no changes in intake compared to before the outbreak. Fruits and vegetables intake was associated with physical activity level, knowledge, and beliefs of foods that may prevent/cure COVID-19. Binary logistic regression identified two significant risk factors of daily fruits and vegetables intake namely, being a non-Chinese (AOR = 1.905, 95% CI = 1.114–3.257) and having good practices scores (AOR = 2.543, 95% CI = 1.611–4.015). Conclusion: The study found a low daily intake of fruits and vegetables. The findings suggested that nutritional interventions are necessary to improve awareness on consuming more fruits and vegetables to improve overall health. [ABSTRACT FROM AUTHOR]

This article aims to compare the dosimetric performance between knowledge-based plan (KBP) libraries with and without trade-off (TO) exploration using multicriterial optimization (MCO) for tongue cancer patients. The trade-off optimized library (KBP&#95;MCO) contains a minimal number of constituent plans, whereas two nontrade-off optimized libraries contain a minimal and a large number of treatment plans, respectively. Three KBP libraries were created: KBP&#95;100 and KBP&#95;20, each comprising of 100 and 20 manually optimized plans, respectively. Additionally, another KBP library (KBP&#95;MCO&#95;20) was created by reoptimizing the constituent plans from KBP&#95;20 using MCO techniques. A total of 70 tongue plans were validated through these libraries. Validation plans were evaluated for PTV and organ at risk (OAR) doses. Greenhouse-Geisser analysis (ANOVA) and the Bonferroni procedure (t-test) were used for statistical evaluation. The mean PTVD95% for KBP&#95;100, KBP&#95;20, and KBP&#95;MCO&#95;20 was 98.4% ± 0.3%, 98.9% ± 0.2%, and 98.7% ± 0.2%, respectively. The statistical significance of PTVD95% for the 3 possible combinations-KBP&#95;100 vs KBP&#95;20, KBP&#95;100 vs KBP&#95;MCO&#95;20, and KBP&#95;20 vs KBP&#95;MCO&#95;20 were statistically significant with p < 0.001. Spinal cord doses for KBP&#95;100, KBP&#95;20, and KBP&#95;MCO&#95;20 were 29.6 ± 1.8 Gy, 31.2 ± 2.5 Gy, and 26.8 ± 1.9 Gy, respectively, with p(KBP&#95;100 vs KBP&#95;20) = 0.14, p(KBP&#95;100 vs KBP&#95;MCO&#95;20) = 0.001, and p(KBP&#95;20 vs KBP&#95;MCO&#95;20) < 0.001. Only the first comparison showed a statistically insignificant variation. A trade-off optimized plan library with a minimal number of patients (20) yields better performance for serial structures (spinal cord and brainstem) compared to large manually optimized KBP libraries. For other organs at risk (OARs) and target dose coverage, although statistical differences were significant in most instances, the differences in physical dose were small and probably will not yield any significant clinical differences., Competing Interests: Conflicts of Interest None., (Copyright © 2024 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.)

The study aims to analyse factors such as perceived ease of use, technology and communication and institution involvement in influencing the effectiveness of online systems and applications for final online examinations held at International Islamic University College Selangor (KUIS) during the period of movement control order (MCO) 2020. Basic model of Technology Acceptance Model (TAM) is applied in this research to study the effectiveness of online systems and applications used by students of KUIS who undergo final online examinations during MCO 2020. This is a quantitative research and questionnaires have been used as the research instrument. The questionnaires were distributed to KUIS students� who took part in the final online examinations during MCO 2020 and a total of 351 data have been collected. Through multiple regression analysis, it is discovered that perceived ease of use and technology are the main factors that influence the most towards the effectiveness of online systems and applications for final online examinations purposes at KUIS while institution involvement factor influences the least. As a conclusion, by studying through these factors, the findings of this research study can serve and be beneficial towards KUIS and the teaching staff in the direction of improving the effectiveness of using online platforms for online examination purposes.

Academic motivation and the elements that influence it have long been a source of concern for educational institutions. Self-efficacy has been identified as a significant component in academic motivation, interest, and academic achievement. Educators have long struggled with how to motivate their students. Self-efficacy is thought to be a significant determinant of a student's motivation. This quantitative research was undertaken to examine the relationship between self-efficacy and academic motivation among university and college students enrolled in Kuala Lumpur during Movement Control Period (MCO). A total of 120 (31 males, 89 females) undergraduates were selected through snowball sampling and participated in the research. Respondents completed two questionnaires, General Self-efficacy Scale (GSE) and Academic Motivation Scale (AMS), which measured their self-efficacy and academic motivation. Findings revealed that the level of academic motivation is higher than the level of self-efficacy among the undergraduates, and there is a statistically significant positive correlation between self-efficacy and academic motivation (rs(120) = .204, p = .026 < .05). This research has provided implications in which it enables educational institutions to respond by providing appropriate assistance in the use of technology and information systems to make the environment of virtual learning as convenient as feasible for students to increase their selfefficacy and academic motivation. [ABSTRACT FROM AUTHOR]

Covid-19 and the subsequent Movement Control Order (MCO) imposed by the government has deeply impacted the higher education institutions in Malaysia. The new normal has dramaticallytransformed to online learning. Universiti Teknologi Malaysia (UTM) took the bold move to be among the first universities in Malaysia to start online learning to ensure that students can continue with their education and graduation as anticipated. Whilst academics have done a remarkable job in putting together materials and assessments in preparation for online delivery of courses, the university must ensure quality and fair assessment as well as how well they have fared in the face of a major catastrophe. Accordingly, evaluations should be carried regularly, especially from the perspectives of students. The purpose of this paper is to explore the online learning experience of international undergraduate students on philosophy course. The paper adopted educational action research method by developing and distributing a questionnaire using google forms to collect data from 88 students in two international sections during the academic year 2020/2021. The results showed that although the majority of students rate their overall online experience as "excellent", however, 60% of them think that their learning outcome could have been better if the study was face to face. Regarding the teaching modes, the preferred selection of majority of students was hybrid, synchronous, and asynchronous modes respectively. Moreover, the findings indicated that that students are still coping with the new norms working from thehome, but they had dissatisfaction with certain elements such as missing the face-to-face interaction and the challenge to carry out collaborative group projects while dispersed in different places. The findings provide updated insights on online learning after being adopted as a new norm during the COVID-19 pandemic and applied in UTM ever since, as such, can be useful for the university management, educators' best practices, and similar higher education institutions to enhance and develop new online teaching and learning plans. [ABSTRACT FROM AUTHOR]

Physical distancing is believed to contain the spread of COVID-19 virus. With data provided by COVID-19 Community Mobility Reports from Google, this study examines the mobility patterns at different stages of Movement Control Order (MCO) and investigates whether lower mobility reduces the number of new cases, death cases, and recovery rate. This research also covers the time spent in places such as i) retail and recreation, ii) grocery and pharmacy, iii) parks, iv) transit stations, v) the workplace, and vi) residential areas. As each of these types of places has distinct epidemiological characteristics, they may spread transmission differently. This study also correlates the stock market with mobility patterns of Malaysians in order to evaluate the effectiveness of lockdowns on COVID-19 incidents and its impact on the stock market, in this case; Kuala Lumpur Composite Index (KLCI). Findings of this study highlight the effects of pandemic COVID-19 on stock market daily performance by utilizing prospect and uncertainty theory in predicting the short-term impacts of the epidemic. [ABSTRACT FROM AUTHOR]

As hosts constitute the resource for parasites, an adaptive radiation in a host can drive one in a parasite. In Lake Tanganyika, the diversification of cichlids has often led to a diversification of their Cichlidogyrus monogeneans. Hitherto, Cichlidogyrus nshomboi was known only from Boulengerochromis microlepis, the sole member of Boulengerochromini. Surprisingly, we retrieved this monogenean from Perissodus microlepis, P. straeleni and Haplotaxodon microlepis, belonging to Perissodini. We sequenced the nuclear 18S, 28S, ITS1 rDNA, and the mitochondrial COI genes and studied the morphology of the male copulatory organ (MCO) and the anchors of the attachment organ. This confirmed the conspecificity of the specimens. The occurrence of C. nshomboi on unrelated host lineages could be explained by inheritance from a common ancestor, or by host-switching. We further investigated the genetic and morphological variation across taxonomic (host tribes and species) and geographical scales. Results revealed divergence in ITS1 and COI between parasites infecting different tribes, which could indicate incipient speciation. Additionally, morphological differentiation in the shape and size of anchors was found between these groups, which could be attributed to phenotypic plasticity or to adaptation. Monogeneans from large-bodied B. microlepis had significantly larger anchors, whereas only two of the four measurements differed for the MCO. Unexpectedly, no morphological variation was observed between specimens infecting different species of Perissodini from nearby localities. However, differences were found between C. nshomboi infecting P. microlepis from different parts of the lake, which could be linked to the population genetic structure of the host. [ABSTRACT FROM AUTHOR]

Anna Lindgren,1,2 Erik Fjellstedt,2,3 Anders Christensson2,3 1Department of Nephrology, Skåne University Hospital, Lund, Sweden; 2Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden; 3Department of Nephrology, Skåne University Hospital, Malmö, SwedenCorrespondence: Anna LindgrenDepartment of Clinical Sciences Malmö, Lund University, SUS Malmö, Jan Waldenströms Gata 15, Malmö SE-205 02, SwedenTel +46-46-171698Fax +46-40-337052Email Anna.Lindgren@med.lu.sePurpose: Conventional hemodialysis (HD) treatment has an acceptable removal of small uremic molecules, but so-called “middle molecules” in the range of 0.5– 60 kDa are poorly cleared with HD compared to a native kidney, which may contribute to morbidity in the dialysis population. Hemodiafiltration (HDF) has a better removal of middle molecules compared to HD but is technically demanding and requires well-functioning dialysis access. The newly introduced medium cutoff (MCO) filters have been developed to enhance middle molecule clearance in HD-mode. The aim of this study was to compare reduction ratios (RRs) of molecules with different molecular weights (0.06– 150 kDa) during dialysis with MCO dialyzer (used in HD-mode) compared to online-hemodiafiltration (ol-HDF) treatment with a conventional high-flux dialyzer.Patients and Methods: This is a prospective controlled single-center cross-over study, including 16 patients in Malmö, Sweden. All patients had ongoing post-dilution ol-HDF treatment before the study. The study compared reduction ratios of small-, middle-, and large-sized molecules during a single 4h dialysis treatment with post-dilution ol-HDF (Polyflux 210H) to a 4h dialysis treatment with MCO dialyzer (Theranova 500) in HD-mode. Between treatments, the patients had a washout period of at least two weeks of their ordinary HDF treatment to reach their ordinary steady state.Results: ol-HDF had significantly higher RR for cystatin C (13 kDa), compared to MCO (RR 68.1 vs 65.8, p=0.003), during a 4h dialysis treatment (mean convection volume of 24.5 L for HDF, and mean Qb of 324 mL/min for HDF and 323 mL/min for MCO). There was no significant difference in the RR for other middle molecules, or for smaller or larger molecules.Conclusion: Overall, the RRs were comparable for ol-HDF and MCO-HD. There was a slightly higher RR of cystatin C (a small middle molecule) for HDF compared to MCO but no difference in other measured molecules.Keywords: chronic hemodialysis, dialysis, hemodiafiltration, hemodialysis, MCO, uremic toxins

The WHO reported the Covid-19 outbreak infected 486,761,597 people, involving 6,142,735 deaths worldwide as of 1 April 2022. This contagious disease has spread rapidly throughout the world, including Malaysia. Since the outbreak in Malaysia began in March 2020, the Movement Control Order (MCO) has been implemented nationwide, leaving a significant impact on its citizens, non-citizens, as well as refugees. There is some exploitation of refugees, where enforcement officers are targeting them for criminal offences. Stakeholders claimed the Malaysian government did not provide any assistance to refugees during the pandemic, including health care and economy. This article examines Malaysia’s responsibilities as a host country to refugees during the Covid-19 outbreak. The Malaysian government is proposed to continuously support refugees on humanitarian grounds based on the country’s economic development capabilities. This paper will look into the current situation of the Refugees in Malaysia; discuss the challenges that the Refugees in Malaysia are facing; analyse the legal [ABSTRACT FROM AUTHOR]

Sporting events at international, regional and national levels have either been postponed or canceled due to the coronavirus outbreak across the globe. The sports industry has been heavily impacted and, in many ways, paralyzed by the pandemic. However, sports and recreational premises or facilities can still carry out certain operations limited to management and maintenance only; quarantine-based centralized training programs by the National Sports Council and camp-based training by state sports councils in Malaysia. The goal of this presentation is to answer questions and provide beneficial information to help increase understanding of the effect of the Covid-19 pandemic on sports activities. The pandemic has in a way put a certain degree of a halt to sports activities that require body contact or direct physical touch. This is what martial art is all about and most of the activities are restricted during the outbreak due to the nature of the sport itself. This paper reports the results of interviews done with those who are involved directly in the martial art sports of Taekwondo. The combination of deductive and semantic approaches of the Thematic Analysis method is used to analyze explicit opinions expressed in interviews done. The findings showed the responses of what has been anticipated by the researchers based on prior knowledge and the current situation. In addition, the suggestions given by the informants could be considered as the basis of innovative ways and strategies to alleviate the impact of Covid-19. More research could be done in future as part of the contribution to the new knowledge and solution of the everexisting hardship during the pandemic. [ABSTRACT FROM AUTHOR]

The global pandemic of Covid-19 has affected the teaching and learning of the STCW courses (Standards of Training, Certification and Watch-keeping for Seafarers) which witnessed the drastic move from normal faceto-face facilitation to full online and distance learning (ODL). This new paradigm shift has resulted in significant changes as well as immense challenges to students who experienced this crisis for the first time. Hence, the study aims to discover students’ motivation level in adapting to the new environment of online learning as experienced by semester 2 students in Maritime English classes via quantitative study adopted Keller’s ARCS Model of Motivation survey administered on 78 respondents. The data collected were analysed and the results showed high level of students’ motivation despite having to undergo challenges in online distance learning during the MCO. Moreover, the four elements of the ARCS Model tested in the experiment indicated very high scores in students’ engagement, confidence, motivation, and satisfaction. This preliminary study has helped to provide a new perspective on online learning as well as students’ motivation to the maritime education and training institutions. Hence, it is hoped that the findings could help them to make continuous quality improvement in pedagogical, technological adaptation and assessment aspects for the benefit of students and stakeholders of the maritime industry. [ABSTRACT FROM AUTHOR]

It is an established fact that the COVID-19 pandemic has had a considerable effect on employment in the tourism and hospitality industry. From the perspective of universities, this problem has brought several repercussions to student interns because their positions as interns have become highly vulnerable during this time of crisis. In this regard, this paper aims to investigate the challenges faced by student interns during the implementation of Movement Control Order (MCO) 1.0 in Malaysia. The analysis of this paper focuses on UUM student interns majoring in Tourism Management. The experiences of 25 practicum students were gathered through semi-structured interviews and the interview transcripts were analysed using content analysis. The findings of this paper suggest that all tourism practicum students have been physically or psychologically affected to a certain degree by the enforcement of the MCO. Among the difficulties encountered by practicum students during the MCO include early termination, working from home and working outside of their job scope. Overall, the findings of this paper offer insightful thoughts for tourism internship by highlighting key aspects in managing practicum students during times of crisis. For future studies, it is important for researchers to explore the long-term effects of lockdowns to university students, particularly on their future careers in tourism, which strongly requires industry exposure. [ABSTRACT FROM AUTHOR]

The severity of Covid-19 outbreak caused it to be declared a pandemic and the Malaysian government had to implement movement control order (MCO). MCO includes restriction on outdoor activities and temporary shutdown of fitness centres. Sports enthusiasts among community may experience uneasy phenomenon as this order affecting their exercises routines. To some extent, it does affect them physically, mentally, and emotionally. Various efforts were made to allow these group to engage in physical exercise. One of the efforts is engaging in live virtual physical exercise (VPE) through social media or recorded videos. Therefore, this study aims to analyse the relationship between VPE and mental health status during COVID-19 pandemic lockdown situation. In this quantitative designed study, 84 participants were recruited randomly within Johor community using snowball effect strategy. DASS-21 questionnaire was used to measure mental health status and administered online for data collection. SPSS software was used for descriptive statistic and SmartPLS software was used to test the structural equation model between the variables. Findings showed significant decreases in the level of stress, anxiety, and depression after joining the VPE programme during MCO. The depression scale was significantly corelated to stress and anxiety before and after involvement with VPE programme. Overall, participants has improved mental health status by engaging with the VPE programme during the lockdown order. This study is expected to shed some light on the future of physical activities via technology and online platform, their influence towards healthy lifestyle and the mental status of the community. [ABSTRACT FROM AUTHOR]

Gene therapy of retinal diseases using recombinant adeno‐associated virus (rAAV) vector‐based delivery has shown clinical success, and clinical trials based on rAAV‐based optogenetic therapies are currently in progress. Recently, we have developed multi‐characteristic opsin (MCO), which has been shown to effectively re‐photosensitize photoreceptor‐degenerated retina in mice leading to vision restoration at ambient light environment. Here, we report the biodistribution of the rAAV2 carried MCO (vMCO‐I) in live samples and post‐mortem organs following intraocular delivery in wild‐type dogs. Immunohistochemistry showed that the intravitreal injection of vMCO‐I resulted in gene transduction in the inner nuclear layer (INL) but did not induce detectable inflammatory or immune reaction in the dog retina. Vector DNA analysis of live body wastes and body fluids such as saliva and nasal secretions using quantitative polymerase chain reaction (qPCR) showed no correlative increase of vector copy in nasal secretions or saliva, minimal increase of vector copy in urine in the low‐dose group 13 weeks after injection and in the faeces of the high‐dose group at 3–13 weeks after injection suggesting clearance of the virus vector via urine and faeces. Further analysis of vector DNA extracted from faeces using PCR showed no transgene after 3 weeks post‐injection. Intravitreal injection of vMCO‐I resulted in few sporadic off‐target presences of the vector in the mesenteric lymph node, liver, spleen and testis. This study showed that intravitreal rAAV2‐based delivery of MCO‐I for retinal gene therapy is safe. [ABSTRACT FROM AUTHOR]

Malaysia is considered as one of the countries with the highest novel corona virus (COVID-19) infected cases in Southeast Asia. Recent studies have identified that the air quality of a region also governs the transmission of the virus through pollutants. Hence, a study was conducted to assess the influence of air quality on the COVID-19 pandemic spread in central Peninsular Malaysia and Sabah. An attempt was also made to infer the effect of monsoonal precipitation on air quality. Central Peninsular Malaysia consists of major cities like Kuala Lumpur, Selangor and Putrajaya. These cities are highly populated, with the expansion of industrial activities, rapid urbanisation and greater usage of vehicles has resulted in air quality deterioration. Such conditions have led to related public health issues, compared to Sabah in east Malaysia. In this study, COVID-19 infected cases, air quality index (AQI) and precipitation data were collected from 25 January to August 2020 to infer the relationship of air quality to the pandemic spread before, during and after the implementation of lockdown periods in the country, referred as movement control order (MCO). The lockdown periods fall under various monsoon climate patterns in the country. Interpretation of data reveals that the variation in air quality correlates with the infected cases. Improved air quality was observed during the last phase of MCO with a lesser number of infected cases. The HYSPLIT model was adopted to study the backward air mass trajectories for different time frames to identify the variation in the sources of pollutants reaching the study area. The study determined that the air pollutants have reached the study area from various directions, reflecting a mixed contribution from the ocean and land area. The relationship between high precipitation (during inter-monsoon and SW monsoon) and improved air quality reveals the washout effect of air pollutants. The outcome of this study inferred that the variation of air quality and precipitation rates facilitate the pandemic spread in this region in addition to the other meteorological factors, apart from individual immune capacity and social distancing. [ABSTRACT FROM AUTHOR]

This study has highlighted the trend of recently-reported dengue cases after the implementation of the Movement Control Orders (MCOs) caused due to COVID-19 pandemic in Malaysia. The researchers used the dengue surveillance data published by the Malaysian Ministry of Health during the 3 phases of MCO (which ranged between 17th March 2020 and 28th April 2020) was used for determining the cumulative number of dengue patients. Thereafter, the dengue cases were mapped using the Geographical Information System (GIS). The results indicated that during the 42 days of MCO in Peninsular Malaysia, 11,242 total cases of dengue were reported. The daily trend of the dengue cases showed a decrease from 7268 cases that occurred before the MCOs to 4662 dengue cases that occurred during the initial 14 days of the COVID-19 pandemic (i.e., MCO I), to 3075 cases occurring during the MCO II and 3505 dengue cases noted during MCO III. The central peninsular region showed a maximal decrease in new dengue cases (52.62%), followed by the northern peninsular region (1.89%); eastern coastal region (1.25%) and the southern peninsular region (1.14%) during the initial MCO implementation. However, an increase in the new dengue cases was noted during the MCO III period, wherein all states showed an increase in the new dengue cases as compared during MCO II. The decrease in the pattern was not solely based on the MCO, hence, further investigation is necessary after considering different influencing factors. These results have important implication for future large-scale risk assessment, planning and hazard mitigation on dengue management.

Rank Set Sampling (RSS) is an alternative to simple random sampling was proposed by McIntyre (1952): Under such sampling scheme various authors have proposed the ratio rank set estimators in order to estimate the population parameters by using OLS (Ordinary Least Square) method. A big issue emerge that when outliers are present in data in that case all the estimators suggested by different authors can give distorted results as OLS is very sensitive to outliers. So in the present study we mainly focus on this issue and adapted the Huber M estimation Technique on the estimator suggested by Al-Odat (2009) instead of OLS, in order to get precise results in case of presence of outliers in data. [ABSTRACT FROM AUTHOR]

This empirical paper investigates how the mompreneurs manage their businesses during the Covid-19 lockdown and how the pandemic affects their family. The role of a mother in a family encompasses the livelihood of the family members, which extends to the family’s financial standing. A mother’s role in a family ranges from a homemaker and, to a certain extent, a financial provider. In Malaysia, it was reported in 2018 that 60.2% of entrepreneurs are housewives. However, it is believed that many women are working at and from home with high cost of living, especially in urban areas. They become home-based entrepreneurs, especially during this unprecedented pandemic, i.e. Covid-19, and restricted by the Movement Control Order (MCO). This study adopted an exploratory qualitative study whereby six (6) mompreneurs who are operating their businesses from home were interviewed to understand how the pandemic and the lockdown have affected their lives. This paper further examines their coping mechanism to the pandemic and financial income during this crisis. Mompreneurs’ financial literacy is also observed in this paper to explore their financial understanding. This research is an exploratory study, and it only provides general ideas on how a home-based businesswoman survive and cope during the lockdown. The findings from this paper are suitable to be used as a benchmark for an extensive quantitative study in the future to further understand the behaviour of the mompreneurs, especially in Malaysia. [ABSTRACT FROM AUTHOR]

The year 2020 was being ushered in by a global pandemic. Within months, COronaVIrus Disease (COVID-19) has spread to almost every country. With its long incubation period and highly contagious characteristics, most countries have initiated lockdown and social distancing is the new norm in most societies. Malaysia implemented the Movement Control Order (MCO) on 18 March 2020 when the cumulative COVID-19 cases were still below 800. Since then, MCO was extended several times and the latest phase of Recovery MCO (RMCO) will last until 31 August 2020. As seafood represents an important protein source, the aquaculture sector supports the livelihood of coastal communities in Malaysia, particularly those involved in micro- and small-scale fish farming activities. The emergence and spread of this pandemic severely disrupt market demand and supply chains of seafood industries. Therefore, this case report looks into the potential impacts of COVID-19 on the aquaculture sector of Malaysia. Then, the coping strategies implemented by Malaysia are highlighted and their potential effectiveness is discussed. Also, some useful recommendations are suggested to ensure the continuity and growth of the aquaculture sector. We believe that insights in this report are applicable to other sectors and countries with similar economic characteristics.

The government of Malaysia has declared the Movement Control Order (MCO) for the whole nation in order to flatten the curve of COVID-19 infection. The MCO has, among others, caused parties in a contract to question the effect of the MCO on the contract. As the areas of law are wide, this paper aims to discuss the effect of MCO on a tenancy contract. The paper analysed the legal position of doctrine of frustration and force majeure clause in the context of tenancy contract in Malaysia. The analysis was done based on the law cases and legal provisions in Malaysia. Reference was also made to case law from the United Kingdom and Singapore as their law is in pari materia with Malaysian law and they are persuasive in nature. This paper found that the doctrine of frustration can be invoked if the performance of the obligation under the tenancy contract is prevented due to the MCO. However, the court will apply the doctrine of frustration in a very careful manner to respect the sanctity of the agreement. As for the force majeure clause, it can be successfully invoked if the scope of the clause covers the event in question, such as the MCO. In conclusion, whether a tenancy contract can be terminated due to the MCO, it will depend on the terms of each tenancy contract. [ABSTRACT FROM AUTHOR]

Résumé: L'objectif de ce travail est de mesurer l'effet de l'ouverture commerciale et des institutions du marché du travail sur l'emploi des jeunes en Afrique. Pour ce faire, nous avons considéré un ensemble de 38 pays sur la période 2000–2018. Les méthodes d'estimation utilisées portent sur les moindres carrés ordinaires (MCO), la méthode instrumentale (doubles moindres carrés‐2SLS) et la méthode des moments généralisés en système (MMG‐système). Les résultats révèlent que l'ouverture commerciale et la rigidité des institutions du marché du travail ont un effet positif et significatif sur l'emploi des jeunes en Afrique. Par contre, l'ouverture commerciale affecte négativement et significativement l'emploi des jeunes sur les marchés du travail rigides. Ces résultats sont valides face à plusieurs tests de robustesse. [ABSTRACT FROM AUTHOR]

To approximate dose-volume histogram (DVH) based quality indicators in volumetric modulated arc therapy (VMAT) planning using multi-criteria optimization (MCO) with a low number of composite optimization parameters. The solution space for VMAT optimization with a low number of composite optimization parameters is approximated by trilinear dose inter- polation and prediction of dose-volume-histogram (DVH) based plan quality indicator values. To assess the approximation quality a diverse dataset of 44 cranial and 18 spine patient geometries was chosen. Optimization results are governed by three composite parameters focusing on target-organ-at-risk- (OAR)-trade-off, overall healthy tissue sparing, and delivery/quality assurance complexity. 21,266 optimized dose distributions were pre-calculated and the numerical values for a choice of 10 DVH points, referred to as plan quality indicators, were stored to serve as ground truth. Using a subset of 8 and 27 pre-calculated optimization results, dose distributions for unknown parameter values were approximated by trilinear interpolation. The resulting quality indicator values were compared to the previously obtained exact solutions. The magnitude of the deviation between exact and approximated values varied largely with respect to patient geometry and the criterion under investigation. Approximation with 27 pre-calculated results yielded lower deviations than approximation with 8 results, at the cost of a higher pre-calculation workload. Solution space approximation via trilinear dose interpolation in VMAT treatment planning governed by composite optimization parameters is possible without further knowledge of the internal implementation of the underlying optimizer. Maximum average deviations between approxi- mation and actual values of characteristic dose quality indicators below 1% (cranial) and 8% (spine) allow for a quick qualitative assessment of the possible solution landscape. [ABSTRACT FROM AUTHOR]

A Pareto Navigation and Visualization (PNaV) tool is presented for interactively constructing a high-dose-rate (HDR) brachytherapy treatment plan by navigating and visualizing the multidimensional Pareto surface. PNaV aims to improve treatment planning time and quality and is generalizable to any number of dose–volume histogram (DVH) and convex dose metrics. Pareto surface visualization and navigation were demonstrated for prostate, breast, and cervix HDR brachytherapy sites. A library of treatment plans was created to span the Pareto surfaces over a 30% range of doses in each of five DVH metrics. The PNaV method, which uses a nonnegative least-squares model to interpolate the library plans, was compared against pure optimization for 11,250 navigated plans using data envelopment analysis. The visualization of the metric trade-offs was accomplished using numerically estimated partial derivatives to plot the local curvature of the Pareto surface. PNaV enables the user to control both the magnitude and direction of the trade-off during navigation. Proof of principle of PNaV was demonstrated using a graphical user interface with visualization tools to enabled rapid plan selection and a quantitative review of metric trade-offs. PNaV produced deliverable plans with DVH metrics within < 0.4%, 0.6%, and 1.1% (95% confidence interval) of the Pareto surface using plan libraries with nominal plan spacing of 10%, 15%, and 30% in each metric dimension, respectively. The interpolation used for the navigation executed in 0.1 s. The fast interpolation allows for quick and efficient exploration of trade-off options by the physician, after an initial preprocessing step to generate the library. Generation, visualization, and navigation of the Pareto surface were validated for brachytherapy treatment planning. The PNaV method enables efficient and informed decision-making for radiotherapy. [ABSTRACT FROM AUTHOR]

The New England College of Optometry in Boston turns 125 years old in 2019. Throughout its existence, the institution has undertaken several initiatives that changed the profession of optometry both in the United States and globally. The most significant of these are detailed in this history. [ABSTRACT FROM AUTHOR]

Introduction: Correct femoral rotational alignment in total knee arthroplasty (TKA) is important for femoropatellar knee kinematics as well as for the overall clinical success. The goal of the present study was to evaluate how accurately standard instruments of various manufacturers with specific rotational settings in posterior referencing restore the posterior femoral condylar anatomy and allow a rotational alignment which matches a particular anatomic rotational landmark on CT.Methods: The anatomical transepicondylar axis (aTEA) and the posterior condylar line (PCL) were identified and the angle formed by these two axes was measured on 100 consecutive CT scans of knees. A virtual posterior condylar resection was performed relative to the aTEA for femoral sizers of various manufacturers in different external rotations ranging from 3° to 7°. The resections of medial and lateral posterior condyle were calculated as well as the condylar twist angle (CTA) between PCL and aTEA.Results: The posterior condylar resection varied between 9 mm and 14 mm on the medial side and between 4 mm and 10.5 mm on the lateral side. The mean CTA was 5.5° of internal rotation (SD ± 1.9°). External femoral rotation resulted in increased resection of the medial posterior condyle and decreased resection of the lateral posterior condyle.Conclusion: Femoral sizers using a posterior referencing technique increase, with rising external rotation, medial posterior condylar resection to an extent that may exceed the implant thickness in the majority of systems. Surgeons should be aware that current standard instruments do not restore the anatomy of the posterior medial and lateral condyle and do not align the femoral component parallel to the aTEA, which may result in internal rotation of a symmetric femoral component. [ABSTRACT FROM AUTHOR]

• Fabrication of micro-channels using MDPSS pulsed fiber laser micro-engraving process on Si 3 N 4. • The input and output models of the current FLMEP were trained and predicted with the help of the feed-forward ANN model. • MCOs like GRA and RSM were applied to obtain the optimal parametric settings, followed by confirmatory tests from experimentation and the current ANN model. • Dimensional and surface morphology characteristics of channels was scrutinized to divulge the consequences of fiber laser-Si 3 N 4 interaction at microstructural levels. Si 3 N 4 has a unique microstructure and strong atomic bonding, making it a high-performance ceramic (HPC) that can withstand high temperatures without losing strength. Si 3 N 4 ′s natural qualities make it well-suited for technical uses, and it is in high demand for practical biomedical applications. Yet, due to its invulnerability to heat radiation, the fiber laser micro-engraving process (FLMEP) might still leave behind thermic imperfections of poor surface quality. The feasibility of FLMEP requirements, such as pulse frequency, speed, repetition, power, and focal plane position in micro-channel construction, is explored. Furthermore, for the current FLMEP, the input–output models have been trained-predicted-validated with the help of an artificial neural network (ANN). Compared to the experimental result data set, the predictive ANN model based on the 5–25-4 architecture showed the mean square error (MSE = 3.52E−11) and the most potential in boosting confidence, with the slightest error rate. In accession to that, multi-criterion optimization (MCO) was employed by including statistical studies like GRA (grey relational analysis: MCGRAO) and RSM (response surface methodology: MCRSMO) to obtain the optimal predictive solutions. Even though the error values collected via experimental validation suggest that MCGRAO works effectively, the confirmation test results demonstrate that MCRSMO gives better results from the perspective of the optimal solution as per the criteria. Furthermore, the solutions provided by the current MCOs were validated using the ANN model, whose results demonstrate the superiority of the ANN model. Nevertheless, to reveal the implications of fiber laser-Si 3 N 4 interaction at microstructural levels, a reified study on the ablation mechanism followed by dimensional and surface morphology characteristics of channels was scrutinized to divulge the consequences of fiber laser-Si 3 N 4 interaction at microstructural levels. [ABSTRACT FROM AUTHOR]

Metallic interconnects represent the main component of a solid oxide fuel cell (SOFC) stack in terms of weight and volume. They are typically made of ferritic stainless steel (FSS) coated on the air side. At the stack operating conditions, the interconnect is exposed to a dual atmosphere: air at the cathode side; fuel (a hydrogen-rich mixture) at the anode side. The stacks considered in this study were field operated in reformed natural gas for 5000, 9000 and 20,000 h respectively. The analyzed interconnects are made from CROFER22APU and coated on the air side with Co-Mn base spinel. One interconnect has been studied for each stack by sampling and preparing cross section the inlet and outlet positions. The samples were characterized by SEM-EDXS in order to investigate the evolution of the interconnect at the air side. The interaction between the metal substrate and the coating is investigated highlighting the formation of chromia based thermal grown oxide (at the FSS/coating interface) and the solid-state diffusion of Cr and Fe from the metal into the coating. The microstructural features evolving as a function of time are also quantified.

Pseudomonas putida (P. putida) MnB1 is a widely used model strain in environment science and technology for determining microbial manganese oxidation. Numerous studies have demonstrated that the growth and metabolism of P. putida MnB1 are influenced by various environmental factors. In this study, we investigated the effects of hydrogen peroxide (H2O2) and manganese (Mn2+) on proliferation, Mn2+ acquisition, anti-oxidative system, and biofilm formation of P. putida MnB1. The related orthologs of 4 genes, mco, mntABC, sod, and bifA, were amplified from P. putida GB1 and their involvement were assayed, respectively. We found that P. putida MnB1 degraded H2O2, and quickly recovered for proliferation, but its intracellular oxidative stress state was maintained, with rapid biofilm formation after H2O2 depletion. The data from mco, mntABC, sod and bifA expression levels by qRT-PCR, elucidated a sensitivity toward bifA-mediated biofilm formation, in contrary to intracellular anti-oxidative system under H2O2 exposure. Meanwhile, Mn2+ ion supply inhibited biofilm formation of P. putida MnB1. The expression pattern of these genes showed that Mn2+ ion supply likely functioned to modulate biofilm formation rather than only acting as nutrient substrate for P. putida MnB1. Furthermore, blockade of BifA activity by GTP increased the formation and development of biofilms during H2O2 exposure, while converse response to Mn2+ ion supply was evident. These distinct cellular responses to H2O2 and Mn2+ provide insights on the common mechanism by which environmental microorganisms may be protected from exogenous factors. We postulate that BifA-mediated biofilm formation but not intracellular anti-oxidative system may be a primary protective strategy adopted by P. putida MnB1. These findings will highlight the understanding of microbial adaptation mechanisms to distinct environmental stresses.