SVS-VPR: A Semantic Visual and Spatial Information-Based Hierarchical Visual Place Recognition for Autonomous Navigation in Challenging Environmental Conditions

Robust visual place recognition (VPR) enables mobile robots to identify previously visited locations. For this purpose, the extracted visual information and place matching method plays a significant role. In this paper, we critically review the existing VPR methods and group them into three major categories based on visual information used, i.e., handcrafted features, deep features, and semantics. Focusing the benefits of convolutional neural networks (CNNs) and semantics, and limitations of existing research, we propose a robust appearance-based place recognition method, termed SVS-VPR, which is implemented as a hierarchical model consisting of two major components: global scene-based and local feature-based matching. The global scene semantics are extracted and compared with pre-visited images to filter the match candidates while reducing the search space and computational cost. The local feature-based matching involves the extraction of robust local features from CNN possessing invariant properties against environmental conditions and a place matching method utilizing semantic, visual, and spatial information. SVS-VPR is evaluated on publicly available benchmark datasets using true positive detection rate, recall at 100% precision, and area under the curve. Experimental findings demonstrate that SVS-VPR surpasses several state-of-the-art deep learning-based methods, boosting robustness against significant changes in viewpoint and appearance while maintaining efficient matching time performance.

Evolutionary relevance of single nucleotide variants within the forebrain exclusive human accelerated enhancer regions

Background

Human accelerated regions (HARs) are short conserved genomic sequences that have acquired significantly more nucleotide substitutions than expected in the human lineage after divergence from chimpanzees. The fast evolution of HARs may reflect their roles in the origin of human-specific traits. A recent study has reported positively-selected single nucleotide variants (SNVs) within brain-exclusive human accelerated enhancers (BE-HAEs) hs1210 (forebrain), hs563 (hindbrain) and hs304 (midbrain/forebrain). By including data from archaic hominins, these SNVs were shown to be Homo sapiens-specific, residing within transcriptional factors binding sites (TFBSs) for SOX2 (hs1210), RUNX1/3 (hs563), and FOS/JUND (hs304). Although these findings suggest that the predicted modifications in TFBSs may have some role in present-day brain structure, work is required to verify the extent to which these changes translate into functional variation.

Results

To start to fill this gap, we investigate the SOX2 SNV, with both forebrain expression and strong signal of positive selection in humans. We demonstrate that the HMG box of SOX2 binds in vitro with Homo sapiens-specific derived A-allele and ancestral T-allele carrying DNA sites in BE-HAE hs1210. Molecular docking and simulation analysis indicated highly favourable binding of HMG box with derived A-allele containing DNA site when compared to site carrying ancestral T-allele.

Conclusion

These results suggest that adoptive changes in TF affinity within BE-HAE hs1210 and other HAR enhancers in the evolutionary history of Homo sapiens might.

have brought about changes in gene expression patterns and have functional consequences on forebrain formation and evolution.

Methods

The present study employ electrophoretic mobility shift assays (EMSA) and molecular docking and molecular dynamics simulations approaches.

Biological synthesis of hybrid silver nanoparticles by Periploca aphylla Dcne. From nanotechnology to biotechnology applications

Nanotechnology is one of the advanced technologies that have almost universal implications in every field of science. The importance is due to the unique properties of nanoparticles; however, green synthesized nanoparticles are considered eco-friendly. The current project was rationalized to prepare green-synthesized biogenic Periploca aphylla Dcne. silver nanoparticles (Pe-AgNPs) and poly (ethylene glycol) methacrylate coated AgNPs nanocomposites (PEGMA-AgNPs) with higher potential for their application in plant tissue culture for enhancing the biomass of Stevia rebaudiana calli. The increased biomass accumulation (17.61 g/3 plates) was observed on a medium containing virgin Pe-AgNPs 40th days after incubation, while the maximum increase was found by supplementing virgin Pe-AgNPs and PEGMA capped AgNPs (19.56 g/3 plates), compared with control (12.01 g/3 plates). In this study, PEGMA capped AgNPs supplementation also induced the maximum increase in total phenolics content (2.46 mg GAE/g-FW), total flavonoids content (3.68 mg QE/g-FW), SOD activity (53.78 U/ml protein), GSH content (139.75 μg/g FW), antioxidant activity (54.3 mg AAE/g FW), FRAP (54 mg AAE/g FW), and DPPH (76.3%) in S. rebaudiana calli compared with the control. It was concluded that virgin Pe-AgNPs and PEGMA capped AgNPs (hybrid polymer) are potent growth regulator agents and elicitors that can be exploited in the biotechnology field for growth promotion and induction of essential bioactive compounds and secondary metabolites from various commercially important and medicinally valuable plants such as S. rebaudiana without laborious field cultivation.

Vitamin D levels among children, adolescents, adults, and elders in Pakistani population: a cross-sectional study

Background

Vitamin D is not only an essential part of a healthy diet but it is also known as the sunshine hormone. It helps to absorb calcium and phosphate within the body and is essential for the development of teeth and bones in growing children. Deficiency in vitamin D causes weak bones, osteoporosis in older individuals, and osteomalacia in children. It also causes loss of alveolar bone around the teeth, increased dental cavities, and other problems associated with gum disease. It can cause depression, fatigue, and appetite loss. This study aims to observe vitamin D deficiency, insufficiency, and sufficiency among children, adults, adolescents, and elders in the Pakistani population.

Methods

A cross-sectional survey was conducted with 27,880 individuals referred from the general out-patient-department (OPD) to Dow Diagnostic Research and Reference Laboratory (DDRRL) units at Dow University of Health Sciences (DUHS) Karachi, Pakistan, for a period of three months from January to March 2017. They were examined for laboratory findings of serum 25 hydroxyvitamin D levels to determine vitamin D deficiency, insufficiency, and sufficiency among all age groups of both male and female genders.

Results

A total of 26,750 individuals with a mean age of 38 ± 18 years were statistically examined for laboratory findings of serum vitamin D levels. Vitamin D deficiency was observed in 56% of individuals with a mean log of 1.01 ± 0.18 ng/ml serum vitamin D levels, vitamin D insufficiency in 20% of individuals with a mean log of 1.38 ± 0.05 ng/ml serum vitamin D levels and vitamin D sufficiency in 24% individuals with a mean log of 1.63 ± 0.12 ng/ml serum vitamin D levels. The highest percentage of individuals deficient in vitamin D were children and adolescents of age ranging between 6 to 18 years.

Conclusion

The findings of vitamin D deficiency in children and adolescents direct higher authorities in the public health sector to take immediate steps to screen, intervene and educate high-risk populations incorporating vitamin D supplements to establish preventive and therapeutic measures.

Dynamical behaviours and stability analysis of a generalized fractional model with a real case study

Introduction

Mathematical modelling is a rapidly expanding field that offers new and interesting opportunities for both mathematicians and biologists. Concerning COVID-19, this powerful tool may help humans to prevent the spread of this disease, which has affected the livelihood of all people badly.

Objectives

The main objective of this research is to explore an efficient mathematical model for the investigation of COVID-19 dynamics in a generalized fractional framework.

Methods

The new model in this paper is formulated in the Caputo sense, employs a nonlinear time-varying transmission rate, and consists of ten population classes including susceptible, infected, diagnosed, ailing, recognized, infected real, threatened, diagnosed recovered, healed, and extinct people. The existence of a unique solution is explored for the new model, and the associated dynamical behaviours are discussed in terms of equilibrium points, invariant region, local and global stability, and basic reproduction number. To implement the proposed model numerically, an efficient approximation scheme is employed by the combination of Laplace transform and a successive substitution approach; besides, the corresponding convergence analysis is also investigated.

Results

Numerical simulations are reported for various fractional orders, and simulation results are compared with a real case of COVID-19 pandemic in Italy. By using these comparisons between the simulated and measured data, we find the best value of the fractional order with minimum absolute and relative errors. Also, the impact of different parameters on the spread of viral infection is analyzed and studied.

Conclusion

According to the comparative results with real data, we justify the use of fractional concepts in the mathematical modelling, for the new non-integer formalism simulates the reality more precisely than the classical framework.

222 Robotic Surgery: Public Perceptions and Current Misconceptions

Aim

While surgeons and robotic companies are key stakeholders involved in the adoption of Robotic Surgery (RS), the public's role is often overlooked. However, given that patients hold ultimate power over their healthcare decisions, public acceptance of RS is crucial. This study aims to identify public understanding, opinions and misconceptions on RS and present solutions to facilitate its wider integration.

Method

An online questionnaire distributed via social media platforms between February and May 2021 identified the views of UK adults on RS. The data was evaluated using thematic analysis, descriptive statistics, and statistical analysis. Statistical differences in age, gender, education level, and presence in the medical field were also sought.

Results

263 responses were obtained, with 216 (82.1%) analysed. Demographic differences provided significantly different results. Participants were relatively uninformed about RS, with a median knowledge score of 4.00(2.00–6.00) on a 10-point likert scale. Fears surrounding increased risk, reduced precision and technological failure were identified, alongside misconceptions on what RS entails, including it being autonomous. However, providing factual information in the survey about RS statistically increased participant comfort (p=<0.0001). Most (61.8%) participants believed robot manufacturers were responsible for malfunctions, but doctors were held accountable more by older, less educated, and non-medical participants.

Conclusions

This study highlights the role of negative and inaccurate public perceptions surrounding RS in impeding its widespread adoption. Greater emphasis must be placed on patient education in RS to mitigate misconceptions and ensure greater diffusion of its benefits

219 The Opportunities and Challenges of Robotic Surgery: A Surgeon and Robotic Company Perspective

Introduction

As an increasing number of specialties have begun to adopt robotic surgery (RS), its prevalence within the NHS is continually rising. This study aims to establish stakeholders’ opinions on the opportunities and challenges of the widespread adoption of RS.

Method

Participants were recruited through social media platforms such as LinkedIn or via university affiliations and current RS research. Semi-structured interviews of eight surgeons and five company representatives were conducted online. Transcripts were analysed to formulate themes surrounding the opportunities and challenges of RS.

Results

This study identified six common themes amongst shareholders: Perspective, Ethics, Impact of Robotics, Training, Adoption and Finances. The success rates and quality of results offered by RS make it a recognised future surgical staple amongst interviewees. However, the technology remains a contentious subject amongst surgeons, with many doubting whether the benefits outweigh the costs associated with implementation. Such reservations are further exacerbated by the absence of a formal training pathway. National guidelines are necessary to embed RS within the NHS infrastructure, allowing greater standardisation for patients and surgeons. The importance of patient education to address misconceptions was emphasised. Despite current high costs, robotic technology is forecasted to become cheaper with greater use and increased market competition. Interviewees stressed that responsibility for errors lies with the surgeon, but with the manufacturer for instrument malfunctions.

Conclusions

This study highlights stakeholders’ views on the opportunities and challenges of RS. The identified themes should form the basis of the proposed recommendations to facilitate a more widespread adoption of RS.

Prevalence of intestinal nematodes infection in school children of urban areas of district Lower Dir, Pakistan

Abstract Intestinal parasitism is the main cause of disease all over the world and described as a significant community health problem. The current study intended to find out the occurrence and identification of hazard factors linked with IPIs among 4-12 years aged shool-age children residing in Lower Dir district, Pakistan during 2019 - 2020. A cross-sectional school-based study was conducted using a pre-arranged pre-tested survey. Anthropometric data and stool collection were done to obtain the findings. The direct wet mount preparation in saline/iodine/methods was used for stool examination. Data were investigated using the GraphPad Prism 5. A total of 400 children studied (mean age of 8.6±3.6 years) the total incidence rate for the intestinal parasitic disease was established to be 71.75%. Of the 400 children studied, the overall prevalence rate for intestinal parasitic infections was found to 71.75% Ascaris lumbricoides (33.1%), Trichuris trichiura (1.04%), E. vermicularis (1.39%), Hookworm (19.86%) were identified in children living in the study area. We concluded that there is a mass scale campaigns were required to generate alertness about health and sanitation in children and the need for the development of effective poverty control programs because deworming (killing of worm with drugs) alone is not adequate to control parasitic infections.

Presenting Complaints in Acute Dengue Infection and Differences in Presenting Complaints Between Primary and Secondary Dengue Infections

Aim and objectives

To describe the presenting complaints in acute dengue infection, and identify any differences in presenting complaints between primary and secondary dengue infection patients.

Material and methods

This cross-sectional observational study was conducted at the Department of Infectious Diseases and Medicine, Holy Family Hospital, Rawalpindi, from July 2019 to December 2019 during the Dengue Rawalpindi Epidemic 2019. Presenting complaints of patients who fulfilled the inclusion criteria of the study were recorded on a proforma on their admissions and their informed consent was taken. Of these patients, 70 primary and 70 secondary dengue infection patients were randomly selected for comparison of presenting complaints. The two groups were compared using the chi-square test and a P-value of <0.05 was considered significant.

Results

Intermittent fever (88.6%), headache (85%), myalgia (87.9%), arthralgia/bone pain (75%), and retro-orbital pain (47.9%) were common in most dengue patients. Hemorrhagic manifestations, such as rash (15%), epistaxis (11.4%), gum bleeding (15%), melena (7.9%), hematemesis (6.4%), hemoptysis (5.7%), and hematuria (6.4%), were less common.

Abdominal pain was significantly more common in secondary dengue infections (50% in secondary dengue infections compared to 32.9% in primary dengue infections).

Conclusions

Fever, headache, myalgia, arthralgia/bone pains, retro-orbital pain as well as rash, epistaxis, gum bleeding, melena, hematemesis, hemoptysis, hematuria, and decreased urine output despite fluid intake are presenting complaints of dengue infection.

Patients with abdominal pain in addition to the above presenting complaints are more likely to be cases of the more serious secondary dengue infection. 

Death caused by covid-19 in top ten countries in Asia affected by covid-19 pandemic with special reference to Pakistan

The COVID-19 is a contagious viral disease, was first emerged in Wuhan, China in December 2019 and became the whole world on alert. The mortality rate in top most countries in Asia with special reference to Pakistan has been focused. Since February 26 to September 2020 the total confirmed cases and mortality rate was measured through Wikipedia and the notable journals. Iran is the only country having highest number of deaths (5.73%) followed by Indonesia (3.77%) while Saudi Arabia shows the lowest number of deaths as 1.39%. In Pakistan the first case was confirmed in 26th February, 2020. The nCov-19 has closely related to severe acute respiratory syndrome (SARS) hence SARS COV-2 was named. This virus is responsible for more than 33.9 million deaths in over all the world as of 20th September, 2020. The number of new cases is increasing time to time. Sindh province of Pakistan has reported the highest number of cases till September, 20, 2020 as compared to other parts of the country and has the highest number of death followed by Khyber Pakhtunkhwa. Because of the person to person contact the disease is spreading rapidly. The individuals who has already infected with other diseases like cancer or diabetic etc. are vulnerable. The nCOV-19 is the most contagious due to its mode of transmission. There is still no vaccine is available for the treatment of disease caused by nCoV-2019. It is therefore the only option to control this pandemic is to adopt effective preventive measures.

1289 Gender Representation in The Authorship of Surgical Journals

Introduction

Despite the increase in female doctors graduating from medical schools internationally, gender disparity in surgery remains. This disparity is also evident in academic surgery. This study aims to quantify the extent of gender disparity in the authorship of articles in major surgical journals.

Method

The Top 10 Surgical Journals were identified using SCImago Journal Rank indicator. Authorship details for papers published in 2019 were collected. Authors were assigned as female, male or unknown using Gender API software (Gender API, Germany). For each journal, the percentage of first author, last author, corresponding author and all authors split by gender was interrogated. Gender differences by publication type were also identified.

Results

9 of the 10 journals had full names publicly available. Overall, 2414 manuscripts were interrogated which included 16,277 number of authors. Respectively, females and males accounted for 29.8% [22.9-34.9%] (N = 655) and 62.4% [56.3-70.2%] (N = 1419) of first authors, 20.6% [11.8-27.1%] (N = 453) and 74.2% [65.6-84.1%] (N = 1706) of last authors, 23.9% [14.9-29.6%] (N = 510) and 69.9% [60.5-79.3%] (N = 2341) of corresponding authors and in total 27% [19.4-31.6%] (N = 4298) and 65.5% [58.6-73.4%] (N = 9982) of all authors. The wide range in these results could be a result of various factors.

Conclusions

This study has identified a gender imbalance in authorship positions, with the greatest difference observed in the most senior author position. Whether this is reflective of the current disparity observed in senior academic surgery positions or due to gender discrimination is unclear.

1075 Paediatric Injuries Pre And During COVID-19 Requiring an Operative Intervention: The District General Hospital Experience

Aim

To assess the effect of lockdown and the following summer period on paediatric trauma patients who required an operative intervention in a district general hospital.

Method

A single centre retrospective audit was performed on all paediatric patients &lt;16 years requiring an operative intervention. Two study periods were assessed – pre-COVID (22/03/2019- 30/09/2019) and during the COVID-19 pandemic and subsequent summer period (26/03/2020 – 26/09/2020). Data were collected on patient demographics, type of injury sustained, and intervention performed.

Results

During the COVID-19 pandemic 119 operations were performed, compared to 238 operations performed before the pandemic. Distal radius fractures were the most common injury both during and before the pandemic. However, during the pandemic there was a higher incidence of both hand injuries and lower limb lacerations. The most common type of operation both before and during the pandemic was manipulation under anaesthetic, but there was an increased incidence of washouts performed during the pandemic.

Conclusions

Despite extensive restructuring of services due to COVID-19, 119 operations were performed during the pandemic. However, this is 119 fewer operations than the same period of the previous year. The reduced rate of operations could be a consequence of increased parental supervision, and less outdoor activity during the pandemic period, but further research is necessary.

Comparative efficacy of BioMin-F, Colgate Sensitive Pro-relief and Sensodyne Rapid Action in relieving dentin hypersensitivity: a randomized controlled trial

Background

Dentin hypersensitivity (DH) is a sharp toothache that influences a patients' oral health-related quality of life. Oral dentifrices have been marketed for pain relief within a minute for DH. The permanent management of DH is being investigated with the remineralisation potential of bioactive agents in dentinal tubules. This study investigated the relief from pain in DH in one minute after applying over the counter (OTC) dentifrices with Pro-Argin™ and strontium acetate and directly compared them with fluoro-calcium phospho-silicate (FCPS)-based dentifrices for immediate and sustained inhibition of painful stimulus provoking DH.

Methods

A randomised, controlled, triple-blinded clinical trial was conducted with 140 participants clinically diagnosed with DH and equally randomized into four groups with parallel treatment assignment of FCPS, Pro-Argin™, 8% strontium acetate, and sodium fluoride-based OTC dentifrices, and tested for DH with air blast, mechanical, and water jet stimuli on SCHIFF cold air sensitivity scale (SCASS) and visual analogue scale (VAS) at interim efficacy intervals of one minute, three days, two, four, and six weeks, subsequently.

Results

A total of 128 participants completed the trial. All the treatment groups showed statistically significant improvement in DH with p < 0.001 relative to baseline at all time points. Pro-Argin™ showed a greater reduction in DH with mean scores of (1.34 ± 0.68) (4.20 ± 1.70) (3.05 ± 2.17) followed by strontium acetate (1.57 ± 0.81) (4.65 ± 1.87) (3.75 ± 1.97) on SCASS and VAS for mechanical and water jet stimuli, one minute after application. There was no statistically significant treatment difference between the two (p = 0.499). FCPS showed the highest reduction in DH on SCASS and VAS for waterjet stimuli with mean scores of (0.97 ± 0.68) (1.80 ± 1.73) and Pro-Argin™ on VAS for mechanical stimuli with mean scores of (2.15 ± 1.92) in six weeks.

Conclusion

OTC dentifrices with Pro-argin™ and strontium acetate are effective for immediate pain relief from DH, and FCPS could be the best possible treatment option for long term management of DH.

Trial registration

ID: NCT04249336 (https://clinicaltrials.gov/ct2/show/NCT04249336), Date of Registration: January 30, 2020 (Retrospectively registered).

Food handlers: an important reservoir of protozoans and helminth parasites of public health importance

Food handlers plays a primary role in the transmission of pathogenically important protozoans and helminth parasites. This study was aimed to evaluate the prevalence of intestinal pathogenic protozoans and helminth parasites among food handlers in and around University of Malakand, Lower Dir, Pakistan. Stool samples were collected from 642 food handlers (all of male) in a cross-sectional study from January to November, 2017. Wet Mount Techniques and concentration methods by using salt and formol-ether solutions. Three hundred and eighty four cases (59.8%) were found infected with one more parasites. Most of the individuals were found infected with helminth (47.6%) as compared to intestinal protozoans (0.93%). Seventy two cases (11.2%) of the cases presented mixed infection with both intestinal protozoan and helminth parasites. The order of prevalence for intestinal helminth was Ancylostoma duodenale (n = 258, 40.1%), followed by Taeniasa ginata (n=96, 14.9%) Ascaris lumbricoides (n = 54, 8.40%) and Trichuris trichura (n=30, 4.60%). For intestinal protozoa, Entamoeba histolytica/dispar (n = 36, 5.64%) was the only protozoan detected. Mono-parasitism was higher than poly-parasitism. Family size income and education level were the factors significantly (P<0.05) associated in the parasites prevalence. Current research showed that IPIs are primarily the foodborne pathogens still an important public health problem in Pakistan. Effective control programs on parasitic diseases transfer and their associated factors are recommended.

Gender representation in editorial boards of international general surgery journals

Background

Despite women constituting over half of new doctors, gender disparity remains an issue. Surgery has shown particularly slow progress towards gender parity. This study aimed to quantify gender representation within editorial boards of the highest ranking international general surgery journals.

Methods

Surgical journals were collated using two indices: SCImago Journal Rank (SJR) and Journal Impact Factor (JIF). Non-general surgery journals were excluded. Journals were contacted, requesting gender editorial team demographics. Editorial board data were collected via journal websites on 28 November 2019.

Results

The top 25 general surgery journals according to SJR and JIF ranking methods were determined, identifying 28 unique journals. Editorial board data were publicly available for 27 of these 28 surgical journals, and were examined. Women accounted for 20.2 per cent (568 of 2816) of total editorial board positions. Women constituted 11 per cent (4 of 36) of editor-in-chief positions, 32 per cent (29 of 92) of deputy editors, and 19.1 per cent (369 of 1935) of general editorial board positions.

Conclusion

The findings demonstrate gender disparity within editorial boards of the most prominent general surgery journals.

Comparison of Knowledge and Attitude among Medical and Dental Students Towards COVID-19

Aim: To assess and compare the knowledge and attitude of medical and dental undergraduates towards COVID-19 in current setup Study Design: Cross-sectional Place and Duration of Study: Study was done at Ziauddin university Karachi during the period of October 2020 to December 2020 Methodology: Medical and dental students from 1st year to final year were enrolled in the study. Cronbach’s alpha was 0.71. The questionnaire was consisting of demographic variables, questions regarding the knowledge towards COVID-19 and the attitude of medical and dental students. Analysis was done by using SPSS version-20. Frequency and percentages was used to present the categorical data. Comparison between demographic variables and knowledge score was done by using the independent t-test and one-way ANOVA test as appropriate. p-value less than 0.05 was considered as significant. Results: About 56% of participants were female and from 3rd year (25.2%). Comparing with socioeconomic status, the upper class of medical students were having higher score. As the year of study upgraded the students reported higher knowledge score with significant p-values among both medical and dental students. Medical students were having higher knowledge about COVID-19 than the dental students but dental students were having more knowledge about the safety measures. Looking over the attitude, majority of medical students were interested in gaining information about COVID-19. Conclusion: It can be concluded that medical students are having more knowledge about the COVID-19 but the dental students were more aware of the protective measure which should be taken. Both groups of medical and dental students having positive attitude towards limiting the spread of COVID-19.

Evaluation of vegetables grown in dry mountainous regions for soil transmitted helminths contamination

Infection caused by geo-helminth parasites are called geohelminthiasis are one of the global health problems. Vegetables eaten raw is the principal source of transmission of geo-helminth parasites. Pakistani people believe that eating raw vegetables are a significant source to get important vitamins and minerals. Based on the high incidence of pathogenic parasites and cultivating different vegetable types in the study areas, we conducted this study to evaluate the geo-helminth contamination of raw vegetables in northwest Khyber Pakhtunkhwa, Pakistan. This is a descriptive study comprised, 1942 samples of 25 various types of vegetables. The samples were examined in physiological saline solution using sedimentation and centrifugation methods. The findings were analyzed by Graph-Pad version 5. P value less than 0.05 (95% CI) was considered significant. Results showed that 16.5% (n=322) of all vegetables were contaminated with one or more type of geo-helminth parasites. Garlic was the highest (35%) and cauliflower the lowest (4%) contaminated samples respectively. Ascaris lumbricoides was the most common geo-helminth found followed by hook worm species while Trichuris trichura was the least in all the vegetable samples. Leafy vegetables were highly contaminated 25.3% than vegetables with root parts 21.2% and fruity 9.09%. More than half of the contaminated vegetables were contaminated with single species of geo-helminth (P<0.05) while less than half with multiple types of geo-helminth contamination. Ninety two vegetables samples were contaminated with 2 species of parasites (P<0.05) and 45 with 3 (P>0.05) species of geo-helminth parasites. Education level of vendors and means of display were not significantly associated while types of vegetable used were significantly associated with the prevalence of parasites. The findings of this study provide evidence that consumption of raw vegetable has a high risk of acquiring geo-helminth infections. The authors believe that preventing the human to enter to the vegetable farmland for defecation, avoiding the irrigation of agricultural fields via night soil, and educating the people on proper washing and cooking of vegetables may be useful in reducing parasitic infections.

Role of Deep Learning in Loop Closure Detection for Visual and Lidar SLAM: A Survey

Loop closure detection is of vital importance in the process of simultaneous localization and mapping (SLAM), as it helps to reduce the cumulative error of the robot's estimated pose and generate a consistent global map. Many variations of this problem have been considered in the past and the existing methods differ in the acquisition approach of query and reference views, the choice of scene representation, and associated matching strategy. Contributions of this survey are many-fold. It provides a thorough study of existing literature on loop closure detection algorithms for visual and Lidar SLAM and discusses their insight along with their limitations. It presents a taxonomy of state-of-the-art deep learning-based loop detection algorithms with detailed comparison metrics. Also, the major challenges of conventional approaches are identified. Based on those challenges, deep learning-based methods were reviewed where the identified challenges are tackled focusing on the methods providing long-term autonomy in various conditions such as changing weather, light, seasons, viewpoint, and occlusion due to the presence of mobile objects. Furthermore, open challenges and future directions were also discussed.

A Cross-sectional Analysis of Prevalence, Coping Strategies and Potential Causes of Depression among Doctors of Karachi

Aims: The aim of current study is to find out the prevalence of depression in doctors in different hospitals of Karachi and its association with lifestyle, the field of specialty and coping mechanisms. Place and Duration of Study: The sample was collected from 10 different hospitals of Karachi, in a period of one Year i.e., March 2019 to February 2020. Methodology: A descriptive cross-sectional study design using non-probability consecutive type of sampling technique was used. Sample size was calculated at 95% confidence interval and was found to be 368. The sample was classified in two broader categories Surgery & Allied and Medicine & Allied. For identification of depression level, Public Health Questionnaire (PHQ-9) was used. A 28-item questionnaire Brief COPE was used to asses coping mechanisms. Results: In total 400 forms were used for data analysis. The mean age of doctors was 35 ± 4 years, 65% were males while 35% were females, there was a statistically significant association of female gender with depression. Chi-Square was applied to determine the association of depression and departments and it was found to be highly significant with a P < .001. Highest level of depression was found in Orthopedics and Psychiatry departments followed by Surgery and Gynecology. While Otolaryngology was the least depressed department. Chi-square was applied and a statistically significant association of low monthly income and depression with a p-value of 0.02. In Surgery and allied there was a statistically significant association of depression with extensive working hours and lack of facilities with a p-value of 0.01 and 0.04. While in Medicine and allied there was a statistically significant association of depression with a harsh attitude of seniors and an uncomfortable working environment with a p-value of 0.02 and 0.03. A linear regression model comparing depression and its associations with coping strategies was applied. Conclusion: Our study shows that depression is present in a vast majority of doctors from multiple specialties. Various risk factors for depression have also been identified so appropriate coping strategies should be formulated to deal with it.

Biochemical studies on protein, phenolic contents and antioxidant activities of Sida cordifolia extracts

The study aimed to characterize the antioxidant properties regarding the Sida cordifolia with special reference to its detailed biochemical analysis. The study revealed that chlorophyll A (0.9 ± 0.3 mg/g), total chlorophyll content (3.0 ± 0.7 mg/g), total carotenoid content (0.3 ± 0.1 mg/g), total soluble proteins (7.5 ± 0.1 mg/g), and total phenolic contents (5.6 ± 1.3 mg/g) were found highest in flower tissue of S. cordifolia. However, peroxidase (POD) contents (118 ± 31 units/g), superoxide dismutase (SOD)  activity (64 ± 1.5 units/g) were maximum in the leaf tissues, while catalase (CAT)  contents (133 ± 25 units/g), ascorbate peroxidase (APX)  contents (145 ± 44 units/g) were also found more in the flowers of S. cordifolia rather than other parts. Our results conclude that leaves, stem, flower of S. cordifolia could be exploited in pharmacology due to presence of different antioxidants reflected in flower and leaf extract make them potent and profound therapeutic agents.                     KEY WORDS: Alkaloids, Flavonoids, Phenolics, Antioxidant, Sida cordifolia   Bull. Chem. Soc. Ethiop. 2020, 34(2), 427-434 DOI: https://dx.doi.org/10.4314/bcse.v34i2.18

Clothoid: An Integrated Hierarchical Framework for Autonomous Driving in a Dynamic Urban Environment

In recent years, research and development of autonomous driving technology have gained much interest. Many autonomous driving frameworks have been developed in the past. However, building a safely operating fully functional autonomous driving framework is still a challenge. Several accidents have been occurred with autonomous vehicles, including Tesla and Volvo XC90, resulting in serious personal injuries and death. One of the major reasons is the increase in urbanization and mobility demands. The autonomous vehicle is expected to increase road safety while reducing road accidents that occur due to human errors. The accurate sensing of the environment and safe driving under various scenarios must be ensured to achieve the highest level of autonomy. This research presents Clothoid, a unified framework for fully autonomous vehicles, that integrates the modules of HD mapping, localization, environmental perception, path planning, and control while considering the safety, comfort, and scalability in the real traffic environment. The proposed framework enables obstacle avoidance, pedestrian safety, object detection, road blockage avoidance, path planning for single-lane and multi-lane routes, and safe driving of vehicles throughout the journey. The performance of each module has been validated in K-City under multiple scenarios where Clothoid has been driven safely from the starting point to the goal point. The vehicle was one of the top five to successfully finish the autonomous vehicle challenge (AVC) in the Hyundai AVC.

A pilot study of the pan-class I PI3K inhibitor buparlisib in combination with cetuximab in patients with recurrent or metastatic head and neck cancer

BACKGROUND

This study assessed the maximum tolerated dose (MTD) of the PI3K inhibitor buparlisib given concurrently with cetuximab in recurrent and metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).

METHODS

Twelve patients with R/M HNSCC were enrolled. Patients were given oral buparlisib starting day 7 and daily thereafter. The dose of buparlisib was escalated in a 3 + 3 design followed by a dose expansion cohort of 6 patients. The MTD of buparlisib per protocol was 100 mg daily with cetuximab given intravenously every 14 days starting day 0.

RESULTS

Ten patients had ≥2 previous treatment regimens (11 with prior cetuximab). There were no dose limiting toxicities observed during dose escalation. One patient achieved a partial response and 4 achieved stable disease.

CONCLUSION

Based on this pilot study, buparlisib at 100 mg daily plus cetuximab proved to be well-tolerated. Patients previously treated with cetuximab monotherapy showed benefit from this combination.

Optima: A phase II dose and volume de-escalation trial for high- and low-risk HPV+ oropharynx cancers

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Background: In this prospective phase II de-escalation study, we used induction chemotherapy to identify favorable HPV+ oropharyngeal cancer (OPC) pts, including those with high-risk tumors, and applied significantly lower radiation or chemoradiation doses than previously reported. Methods: Pts with HPV+ OPC were classified as low-risk (≤T3, ≤N2B, ≤10 PYH) or high-risk (T4 or ≥N2C or > 10 PYH). Pts received 3 cycles of carboplatin (AUC 6, D1) and nab-paclitaxel (100 mg/m2, D1/8/15). 1) Low-risk pts with ≥50% response received low-dose radiotherapy alone to 50Gy (RT50). 2) Low-risk pts with 30-50% response OR high-risk pts with ≥50% response received low-dose chemoradiotherapy to 45Gy (CRT45). 3) All other ( = poor response) pts received regular-dose CRT (CRT75). All pts also received de-escalated RT volumes limited to the first echelon of uninvolved nodes. CRT consisted of paclitaxel, 5-FU, hydroxyurea, and 1.5Gy twice daily RT every other week. Primary site biopsy and neck dissection were performed only after de-escalated treatment (RT50, CRT45) for pathologic confirmation. The primary endpoint was 2-year PFS. Secondary endpoints included pathologic complete response (pCR) rate and toxicity. Results: 62 pts were enrolled. 28 pts (45.2%) were low-risk and 34 pts (54.8%) were high-risk. 71.4% of low-risk pts received RT50 and 21.4% received CRT45. 70.6% of high-risk pts received CRT45. The pCR rate was 94.4% after RT50 and 92.3% after CRT45. Median follow-up is 1 year. The 2-year PFS and OS were both 100% for low-risk pts, and 91.6% and 97.0% for high-risk pts. Significant decrease in the rates of grade ≥3 mucositis (15.8% RT50, 46.4% CRT45, 60.0% CRT75, p = .033) and grade ≥3 dermatitis (0% RT50, 21.4% CRT45, 30.0% CRT75, p = .056) were observed. PEG-tube dependency was improved at 3 months (0% RT50, 14.8% CRT45, 70.0% CRT75, p < .001) and 6 months (0% RT50, 3.7% CRT45, 20.0% CRT75, p = .066) post-treatment. Conclusions: Favorable response to induction chemotherapy appears to be a powerful biomarker for dose and volume de-escalation with 50Gy RT or 45Gy CRT. Outstanding survival and high pCR rates suggest that completion neck dissection may not be necessary. Toxicity and functional outcomes are significantly improved. Clinical trial information: NCT02258659.

Correlation of constitutive PD-1 resistance in HNC with GM-CSF expression and presence of myeloid derived suppressor cells (MDSCs)

6049

Background: PD-1 checkpoint blockade is active in head and neck squamous cell carcinomas (HNC) with a response rate of ~18% and significant impact on survival. However, only a subset of patients benefits (Seiwert, Lancet Oncol). Biomarkers such as PD-L1 IHC and the Interferon-Gamma gene expression profile (INF-G GEP) identify inflamed tumors with a higher chance of response (~35-40%). However, it remains unclear why the majority of INF-G inflamed tumors still do not respond, or how to overcome constitutive resistance. Methods: 50 anti-PD-1 treated recurrent/metastatic HNC patients were included. Tumor RNA was analyzed using a 638-gene immune panel on the Nanostring nCounter. HPV status was assessed by HPV E6/E7 mRNA. T-cell inflamed phenotype was calculated using the 6-gene INF-G GEP (geometric mean) using both a low (6) and a high cutpoint. Differential gene expression was determined between inflamed-benefitting (IB) patients (defined as OS ≥ 250days), and inflamed-non-benefitting (INB) patients. Candidate biomarkers were evaluated in the entire cohort. Results: CD8 correlated highly with INF-G GEP (R = 0.80), suggesting T cell-driven inflammation. Comparing inflamed benefitting with inflamed non-benefitting tumors, the most differentially expressed gene was CSF-2, encoding GM-CSF, with 4-fold higher expression in inflamed non-benefitting (INB) tumors (with both cutpoints). In the overall anti-PD-1 treated cohort of 50 patients, CSF-2/GM-CSF correlated strongly with poor overall survival (P = 0.02), outperforming both HPV status, or PD-L1 expression in cox PH multivariate analysis. GM-CSF expression has been linked to myeloid derived suppressor cells (MDSC); MDSC marker CD34, as well as JAK2/IL10 were significantly elevated in inflamed non-benefitting (INB) tumors. There was no difference in M2 macrophage marker CD163 between the two groups. Conclusions: Constitutive resistance to PD-1 checkpoint blockade in inflamed HNC associates with expression of GM-CSF and Myeloid Derived Suppressor Cell (MDSC) markers. Strategies to deplete MDSCs, such as chemotherapy, should be considered in combination or sequentially with anti-PD-1.

Presence of small sessile serrated polyps increases rate of advanced neoplasia upon surveillance compared with isolated low-risk tubular adenomas

BACKGROUND AND AIMS

The U.S. Multi-Society Task Force (USMSTF) stratifies patients with sessile serrated polyps (SSPs) without cytologic dysplasia of <10 mm in size as at low risk for metachronous advanced neoplasia and recommends management similar to low-risk conventional tubular adenomas. Evidence supporting the recommended surveillance interval for these low-risk SSPs is limited. We aimed to assess rates of metachronous advanced neoplasia based on the presence of an initial low-risk SSP compared with isolated low-risk tubular adenomas.

METHODS

Colonoscopy data were retrieved for 2260 patients found to have an adenoma or SSP on pathology records between 2005 and 2011 at an academic medical center. The 788 patients who met study design criteria were stratified into 4 groups based on the presence of a high- or low-risk adenoma (HRA or LRA) and of a synchronous SSP on initial colonoscopy. The rates of advanced neoplasia at surveillance colonoscopy were then compared between groups.

RESULTS

The rate of advanced neoplasia at surveillance in the LRA inclusive of SSP group (12/66, 18.2%) was greater than in the LRA without any SSP group (29/370, 7.8%; P = .019). The rate of advanced neoplasia at surveillance in patients with isolated low-risk SSP (10/56, 17.9%) remained significantly greater than those with isolated low-risk tubular adenomas (29/370, 7.8%; P = .024). The rate of advanced neoplasia upon surveillance in the LRA inclusive of SSP group (18.2%) was comparable with the rate observed in the index HRA without any SSP group (15.9%) (40/252, P = .709).

CONCLUSIONS

The rate of advanced neoplasia upon surveillance in patients with initial low-risk SSPs is higher than in patients with initial isolated low-risk tubular adenomas and more similar to patients with initial high-risk tubular adenomas. These findings suggest that the rate of metachronous advanced neoplasia in patients with what are considered by USMSTF as "low-risk" SSPs is higher than in those without SSPs. Therefore, a surveillance interval that accounts for the presence of SSPs even in small lesions without cytologic dysplasia should be considered.

Simplified risk stratification criteria for identification of patients with MRSA bacteremia at low risk of infective endocarditis: implications for avoiding routine transesophageal echocardiography in MRSA bacteremia

The aim of this study was to identify patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia with low risk of infective endocarditis (IE) who might not require routine trans-esophageal echocardiography (TEE). We retrospectively evaluated 398 patients presenting with MRSA bacteremia for the presence of the following clinical criteria: intravenous drug abuse (IVDA), long-term catheter, prolonged bacteremia, intra-cardiac device, prosthetic valve, hemodialysis dependency, vertebral/nonvertebral osteomyelitis, cardio-structural abnormality. IE was diagnosed using the modified Duke criteria. Of 398 patients with MRSA bacteremia, 26.4 % of cases were community-acquired, 56.3 % were health-care-associated, and 17.3 % were hospital-acquired. Of the group, 44 patients had definite IE, 119 had possible IE, and 235 had a rejected diagnosis. Out of 398 patients, 231 were evaluated with transthoracic echocardiography (TTE) or TEE. All 44 patients with definite IE fulfilled at least one criterion (sensitivity 100 %). Finally, a receiver operator characteristic (ROC) curve was obtained to evaluate the total risk score of our proposed criteria as a predictor of the presence of IE, and this was compared to the ROC curve of a previously proposed criteria. The area under the ROC curve for our criteria was 0.710, while the area under the ROC curve for the criteria previously proposed was 0.537 (p < 0.001). The p-value for comparing those 2 areas was less than 0.001, indicating statistical significance. Patients with MRSA bacteremia without any of our proposed clinical criteria have very low risk of developing IE and may not require routine TEE.

Clostridium difficile infection in liver transplant recipients: a retrospective study of rates, risk factors and outcomes

Clostridium difficile infection (CDI) occurs in 3-7% of liver transplant recipients (LTR). However, few data exist on the recent epidemiology, predictors and outcomes of CDI in LTR. A cohort study was performed including LTR from 2000 to 2010 at a tertiary care hospital in Detroit. CDI was defined as diarrhea with a stool C. difficile positive test. Data analyzed included demographics, comorbidities, length of stay (LOS), severity of CDI, rates of recurrence (<12 weeks), relapse (<4 weeks) and overall mortality. Predictors of CDI were calculated using Cox proportional hazard model; 970 LTR were followed for years. Overall prevalence of CDI was 18.9%. Incidence of CDI within 1 year of transplant was 12.4%. Severe CDI occurred in 29.1%. CDI recurrence and relapse rates were 16.9% and 9.7%, respectively. Independent predictors of CDI were year of transplant (hazard ratio [HR] 1.137, 95% confidence interval [CI] 1.06-1.22; p < 0.001), white race (105/162 whites, HR 1.47, 95% CI 1.03-2.1; p = 0.035), Model for End-Stage Liver Disease score (HR 1.03, 95% CI 1.01-1.045, p = 0.003) and LOS (HR 1.01, 95% CI 1.005-1.02, p < 0.001). Significant mortality was observed among LTR with CDI compared to those without CDI (p = 0.003). We concluded that CDI is common among LTR and is associated with higher mortality.

Development of the ITER magnetic diagnostic set and specification

ITER magnetic diagnostics are now in their detailed design and R&D phase. They have passed their conceptual design reviews and a working diagnostic specification has been prepared aimed at the ITER project requirements. This paper highlights specific design progress, in particular, for the in-vessel coils, steady state sensors, saddle loops and divertor sensors. Key changes in the measurement specifications, and a working concept of software and electronics are also outlined.

Active screening at entry for tuberculosis among new immigrants: a systematic review and meta-analysis

Although there is no evidence that imported tuberculosis increases the incidence of the disease in host countries, the rise in migration worldwide raises concerns regarding the adequacy of surveillance and control of immigrant-associated tuberculosis in low incidence countries. Assessing the performance of screening of immigrants for tuberculosis is key to rationalizing control policies for the detection and management of immigrant-associated tuberculosis. We performed a systematic review and meta-analysis to determine the yield of active screening for tuberculosis among new immigrants at the point of entry. The yield for pulmonary tuberculosis was 3.5 cases per 1,000 screened (95% CI 2.9-4.1; I(2) = 94%); for refugees, asylum seekers and regular immigrants the estimates were 11.9 (95% CI 6.7-17.2; I(2) = 92%), 2.8 (95% CI 2.0-3.7; I(2) = 96%) and 2.7 (95% CI 2.0-3.4; I(2) = 81%), respectively. The yield estimates for immigrants from Europe, Africa and Asia were 2.4 (95% CI 1.3-3.4; I(2) = 51.5%), 6.5 (95% CI 3.2-10.0; I(2) = 62%) and 11.2 (95% CI 6.2-16.1; I(2) = 95%), respectively. These results provide useful data to inform the development of coherent policies and rational screening services for the detection of immigrant-associated tuberculosis.

A new acylated flavone glycoside from the fruits of Stocksia brauhica

Phytochemical investigations of the fruits of Stocksia brauhica (Sapindaceae) resulted in the isolation of a new acylated flavone glycoside. Its structure of the new compound brauhenefloroside D (1) was established as 3-O-[(alpha-L-rhamnopyranosyl)oxy]-7-O-[(acetyl)-beta-D-glucopyranosyl (1 --> 4)]-[6-O-(4-hydroxy-E-cinnamoyl)-beta-D-glucopyranosyl-(1 --> 2)-alpha-L-rhamnopyranosyl)-oxy]-kaempferol. The structure elucidation of the new compound was based primarily on 1D and 2D NMR analysis, including COSY, HMBC and HMQC correlations.

SPECTRUM OF HEPATITIS C VIRUS (HCV) GENOTYPES AMONG DIAGNOSED CASES OF HCV IN RAWALPINDI AND ISLAMABAD REGION OVER THE PERIOD OF SIX YEARS

Background: Determination of an individual's HCV genotypes prior to antiviral therapy has become increasingly important for the deciding clinical management and predicting prognosis of HCV infection. Relative genotype proportions are needed to inform to healthcare models, which should be geographically tailored. To our knowledge, there are no studies reporting genotype pattern in Rawalpindi/Islamabad region. We aimed to determine the frequency of different genotypes in HCV positive cases in the population of Rawalpindi/ Islamabad over the period of five years. Methods: Data of total of three thousand eight hundred and eighteen (n=3818) HCV positive adult of both genders were screened for genotype testing over the period of six years were analyzed. Results: Most frequent genotype identified in our study was genotype 3, accounting for 95.8% (n=3657) of HCV positive cases. The second most common genotype was Type 1 accounting for 2.9% (n=109) of HCV positive cases. Other genotypes were Type 2 (0.3%, n=12) and Type 4 (0.1%, n=5). Mixed genotype (Type 1 and 3) were detected in almost 1 % (n=35) of cases. We did not find genotype 5 and 6 in our study sample. No significant difference was observed among males and females in genotype distribution (P>0.05). Conclusion: The most common genotype among HCV patients were found to be genotype 3 followed by genotype 1 as the second most common in Rawalpindi/Islamabad region during the study period.