Management of Postharvest Decay of Tomato Fruit with Inorganic Salts and Natural Products.

Ph.D. Thesis. University of Hawaiʻi at Mānoa 2018

Generating and Validating DSA Private Keys from Online Face Images for Digital Signatures

Signing digital documents is attracting more attention in recent years, according to the rapidly growing number of digital documents being exchanged online. The digital signature proves the authenticity of the document and the sender’s approval on the contents of the document. However, storing the private keys of users for digital signing imposes threats toward gaining unauthorized access, which can result in producing false signatures. Thus, in this paper, a novel approach is proposed to extract the private component of the key used to produce the digital signature from online face image. Hence, this private component is never stored in any database, so that, false signatures cannot be produced and the sender’s approval cannot be denied. The proposed method uses a convolutional neural network that is trained using a semi-supervised approach, so that, the values used for the training are extracted based on the predictions of the neural network. To avoid the need for training a complex neural network, the proposed neural network makes use of existing pretrained neural networks, that already have the knowledge about the distinctive features in the faces. The use of the MTCNN for face detection and Facenet for face recognition, in addition to the proposed neural network, to achieved the best performance. The performance of the proposed method is evaluated using the Colored FERET Faces Database Version 2 and has achieved robustness rate of 13.48% and uniqueness of 100%

Sponge media drying using a swirling fluidized bed dryer

Surface preparation today has seen the introduction of sponge media as an alternative product against the traditionally used abrasive materials. Being soft and elastic, the sponge media reduces air borne emission significantly during surface preparation with capability to be re-used. However the environmental conditions limit the sponge media usage whereby wet surroundings prohibit the re-use of the sponge without being dried properly. This study proposes the swirling fluidized bed dryer as a novel drying technique for sponge media. Batch experiments were conducted to study the bed’s hydrodynamics followed by drying studies for three bed loadings of 0.5 kg, 0.75 kg and 1.0 kg at three drying temperatures of 80°C, 90°C and 100°C. It was found that, minimum fluidization velocities for the wet sponge particles were found to be 1.342, 1.361 and 1.382 m/s with minimum swirling velocities of 1.400, 1.469 and 1.526 m/s. Drying times were recorded between 6 to 16 minutes depending on bed loading and drying temperature. Smaller bed weights exhibits faster drying with constant-rate drying period while higher drying temperature and larger bed load resulted in falling-rate drying period. Thin layer modelling for the falling-rate region indicates that Verma et. al model provides the best fit for the present experimental data with coefficient of determination, R2 = 0.98773, root mean square error, RMSE = 0.05048, residuals = 0.3442 and reduced chi-square, χ2 = 0.00254. The effective diffusivity, Deff, for 0.5 kg bed load was found to be 3.454 x 10-9 m2/s and 1.751 x 10-9 m2/s for 0.75 kg bed load. In conclusion, SFBD was found to be a viable and efficient method in drying of sponge media for various industrial applications particularly surface preparation

Two-intervention social distancing strategy to control COVID-19 in Mosul city; A Comparative study

Background: Novel coronavirus what known now as COVID-19 pandemic represents worldwide health problem. It presented as an upper respiratory infection, acute respiratory distress syndrome, micro thrombosis, sepsis, septic shock, and multi-organ failure and death. Early recognition of suspected cases allows health staff and local gover-   Nment the sufficient time to initiate the appropriate international and national protocols to control the transmission of infection. Aim:  Evaluate the effectiveness of two- intervention social distancing strategy that was applied to control COVID-19 in Mosul city. Method: Using mathematical simulation model for COVID-19 spread implemented in Santa Clara City in US to estimate the expected burden of the pandemic in Mosul City. This model give a numerical data about the number of the infected cases and time interval of applying the appropriate intervention control strategies by comparing single-strategy (social distancing) to two-intervention strategy (social distancing & light switch approach). Results: The two interventions strategy shows that on average, the baseline epidemic scenario affected 12.3% of the population in comparison to 11.6% with single-strategy at 70% contact rate. While at the rate of 20% of social contact, only 0.11 % of the population will be infected in the two-intervention strategy in comparison to 0.165% when the single strategy applied. This means a significant reduction in the spread of the infection and the peak time incidence in all hypotheses will be significantly delayed. Conclusion: The two- intervention social distancing strategy is an efficient tool to control COVID-19 in Mosul city and this represents a big success for Crisis Cell in controlling the pandemic in Mosul city

The Association of Systemic Microvascular Changes with Lung Function and Lung Density: A Cross-Sectional Study

10.1371/journal.pone.0050224PLoS ONE712

Knowledge, beliefs, attitude, and practices of E-cigarette use among dental students: A multinational survey

E-cigarette use is a trend worldwide nowadays with mounting evidence on associated morbidities and mortality. Dentists can modify the smoking behaviors of their patients. This study aimed to explore the knowledge, beliefs, attitude, and practice of E-cigarette use among dental students. This multinational, cross-sectional, questionnaire-based study recruited undergraduate dental students from 20 dental schools in 11 countries. The outcome variable was current smoking status (non-smoker, E-cigarette user only, tobacco cigarette smoker only, dual user). The explanatory variables were country of residence, sex, age, marital status, and educational level. Multiple linear regression analysis was performed to explore the explanatory variables associated with E-cigarette smoking. Of the 5697 study participants, 5156 (90.8%) had heard about E-cigarette, and social media was the most reported source of information for 33.2% of the participants. For the 5676 current users of E-cigarette and/or tobacco smoking, 4.5% use E-cigarette, and 4.6% were dual users. There were significant associations between knowledge and country (P< 0.05), educational level (B = 0.12; 95% CI: 0.02, 0.21; P = 0.016) and smoking status (P< 0.05). The country of residence (P< 0.05) and smoking status (P< 0.05) were the only statistically significant factors associated with current smoking status. Similarly, there were statistically significant associations between attitude and country (P< 0.05 for one country only compared to the reference) and history of previous E-cigarette exposure (B = -0.52; 95% CI: -0.91, -0.13; P = 0.009). Also, the practice of E-cigarettes was significantly associated with country (P< 0.05 for two countries only compared to the reference) and gender (B = -0.33; 95% CI: -0.52, -0.13; P = 0.001). The knowledge of dental students about E-cigarette was unsatisfactory, yet their beliefs and attitudes were acceptable. Topics about E-cigarette should be implemented in the dental curriculum.Deanship of Scientific Research, King Saud University, for funding through the Vice Deanship of Scientific Research for Research Chairs. Qatar National Library for the open access funding

Oral health practices and self-reported adverse effects of E-cigarette use among dental students in 11 countries: an online survey

Objectives: E-cigarette use has become popular, particularly among the youth. Its use is associated with harmful general and oral health consequences. This survey aimed to assess self-reported oral hygiene practices, oral and general health events, and changes in physiological functions (including physical status, smell, taste, breathing, appetite, etc.) due to E-cigarette use among dental students. Methods: This online, multicounty survey involved undergraduate dental students from 20 dental schools across 11 different countries. The questionnaire included demographic characteristics, E-cigarette practices, self-reported complaints, and associated physiological changes due to E-cigarette smoking. Data were descriptively presented as frequencies and percentages. A Chi-square test was used to assess the potential associations between the study group and sub-groups with the different factors. Statistical analysis was performed using SPSS at P < 0.05. Results: Most respondents reported regular brushing of their teeth, whereas only 70% used additional oral hygiene aids. Reported frequencies of complaints ranged from as low as 3.3% for tongue inflammation to as high as 53.3% for headache, with significant differences between E-cigarette users and non-users. Compared to non-smokers, E-cigarette users reported significantly higher prevalence of dry mouth (33.1% vs. 23.4%; P < 0.001), black tongue (5.9% vs. 2.8%; P = 0.002), and heart palpitation (26.3%% vs. 22.8%; P = 0.001). Although two-thirds of the sample reported no change in their physiological functions, E-cigarette users reported significant improvement in their physiological functions compared to never smokers or tobacco users. Conclusion: Dental students showed good oral hygiene practices, but E-cigarette users showed a higher prevalence of health complications.Dental Biomaterials Research Chair, Deanship of Scientific Research, King Saud University. The funder has no role in the design of the study as well as in the methodology, analysis, and interpretation of the data

Emphysema Predicts Hospitalisation and Incident Airflow Obstruction among Older Smokers: A Prospective Cohort Study

Emphysema on CT is common in older smokers. We hypothesised that emphysema on CT predicts acute episodes of care for chronic lower respiratory disease among older smokers.Participants in a lung cancer screening study age ≥ 60 years were recruited into a prospective cohort study in 2001-02. Two radiologists independently visually assessed the severity of emphysema as absent, mild, moderate or severe. Percent emphysema was defined as the proportion of voxels ≤ -910 Hounsfield Units. Participants completed a median of 5 visits over a median of 6 years of follow-up. The primary outcome was hospitalization, emergency room or urgent office visit for chronic lower respiratory disease. Spirometry was performed following ATS/ERS guidelines. Airflow obstruction was defined as FEV1/FVC ratio <0.70 and FEV1<80% predicted.Of 521 participants, 4% had moderate or severe emphysema, which was associated with acute episodes of care (rate ratio 1.89; 95% CI: 1.01-3.52) adjusting for age, sex and race/ethnicity, as was percent emphysema, with similar associations for hospitalisation. Emphysema on visual assessment also predicted incident airflow obstruction (HR 5.14; 95% CI 2.19-21.1).Visually assessed emphysema and percent emphysema on CT predicted acute episodes of care for chronic lower respiratory disease, with the former predicting incident airflow obstruction among older smokers

APOM and high-density lipoprotein cholesterol are associated with lung function and per cent emphysema

Chronic obstructive pulmonary disease (COPD) is linked to cardiovascular disease; however, there are few studies on the associations of cardiovascular genes with COPD

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio