Effect of Intermittent Water Supply on Water Quality in a Model Pipeloop

Intermittent water supply (IWS) is defined as a piped drinking water distribution system that operates for less than 24 hours per day. Water quality is found to be negatively impacted in IWS, which creates a human health risk. There are still may gaps in our understanding of pathways of contamination in IWS, which has been a limitation in creating appropriate solutions to maintain water quality in IWS systems. To characterize these pathways, we ran a study to investigate the impact of intermittency on water quality, biofilms, and water pressure in IWS, which consisted of constructing two identical model drinking water distribution systems. One was operated as an IWS and the other a continuous water supply(CWS),as a control. Water samples were taken for water quality analysis, biofilms were sampled, and pressure was monitored continuously in these systems. Key finding included a significant decrease in chlorine residual and increases in turbidity, TOC, and microbial concentration as in the water that was first flushed through the IWS pipeloop. However, IWS water quality parameters matched those is the CWS pipeloop or were better over the course of an IWS supply period. This implies the need for management of flush water in IWS systems. In addition, the biofilms in the IWS pipeloop before a supply period were found to have a larger spread than those after a supply period. Lastly, negative pressures were found in the IWS system. These results have implications for future research and IWS operation

A Phenomenological Study of the Relationship Experiences of Partners of Individuals Who Suffer with Premenstrual Dysphoric Disorder (PMDD)

Premenstrual Dysphoric Disorder (PMDD) is a debilitating disorder that adversely affects the lives of individuals and their intimate relationships. The purpose of this transcendental phenomenological study was to describe the lived experience of the partners of individuals who suffer from Premenstrual Dysphoric Disorder. The theories guiding this study were the interpersonal theory of suicide and the adult attachment theory. This study examined the overall relationship experience of partners of individuals suffering from PMDD and their cyclic attachment styles during the luteal and follicular phases of the menstrual cycle. A selection of three PMDD partners and three PMDD sufferers, who have been in an intimate relationship for six months or longer, were interviewed to measure the fluctuation in the overall relationship experience and cyclic attachment styles. Overall, the attachment styles of the PMDD partners may be affected because of the cyclic anguish of the PMDD sufferers during the luteal and follicular phases of menstruation. The fluctuating attachment styles of the PMDD sufferer can impact the PMDD partner’s overall relationship experience

Laparoscopic nephrectomy in Iraqi cat

The aim of this study was to standardize laparoscopic nephrectomy and to study its effects on body status and survival possibility on 8 healthy domestic cats from both sexes. Their age were ranged between 1-2 years. The laparoscopic nephrectomy was easy and feasible by using laparoscopy thermocautery tool. The right kidney was removed in all animals. Time consuming, success of operation and post-operative complications were dependent to support this study. The obtained results of the current study showed short time consuming 30±1.6 min. Procedures were successfully done with mild complications. Laparoscopic thermocautery indicated as an efficient tool for cutting and controlling bleeding at the same time. In conclusion, the use of thermocautery for laparoscopic nephrectomy in cats was feasible and exhibited efficient tools for cutting and securing vessels of the kidney, but the tool had a drawback by producing smoke with in abdominal cavity that partially obscuring the laparoscopic vision

The influence of baseline hardness and chemical composition on enamel demineralization and subsequent remineralization

Indiana University-Purdue University Indianapolis (IUPUI)BACKGROUND Several studies have reported that harder enamel with higher contents of calcium (Ca), phosphorus (P) and fluorine (F) coupled with lower contents of carbonate (C), magnesium (Mg) and nitrate (N) was found to be more resistant to demineralization. Additionally, the hardness of dental enamel was found to have a strong correlation with its chemical content. However, yet to be established is the relation between the physical and chemical structure of enamel and its response to de- and remineralizing conditions. OBJECTIVES The aims of this laboratory study were: 1) To investigate the hardness and chemical content of sound enamel and their influence on demineralization; 2) To investigate these properties in demineralized enamel and their influence on remineralization; and 3) To investigate these properties in sound enamel and their influence on remineralization. MATERIALS AND METHODS Incipient subsurface caries lesions were created in 94 bovine enamel specimens using Carbopol C907 using three demineralization times. The specimens were then pH-cycled and treated using either 367 ppm F sodium fluoride or a placebo. Knoop surface microhardness (SMH), Energy dispersive X-ray spectroscopy (EDS) and Transverse microradiography (TMR) were performed on the specimens at all stages and compared between them. TMR variables included integrated mineral loss (ΔZ), Lesion depth (L) and maximum mineral density of the surface zone (SZmax). Data were analyzed using three- and four-way ANOVA and Pearson correlation coefficients were calculated. RESULTS SMH, ΔZ, L and SZmax were significantly different among stages, demineralization times and treatment. The weight% of F at the surface was significantly affected by treatment, irrespective of demineralization time. A statistically significant moderate correlation was found between SZmax and ΔZ and SZmax and L after pH cycling. SMH also correlated weakly to moderately with TMR data. CONCLUSIONS SMH and SZmax decreased while ΔZ and L increased with increased demineralization time. Both fluoride and non-fluoride specimens were able to remineralize, which emphasizes the role of saliva in mineralization. The Ca:P ratio remained stable at various stages, indicating the stoichiometric dissolution and redeposition of minerals. The greatest deposition of F was at the surface and its increase led to an increase in SMH and SZmax. SMH values showed that harder specimens at baseline and after demineralization remained hard after demineralization and pH-cycling, respectively, although this correlation was weak. Additionally, harder lesions showed less L and ΔZ and greater SZmax. RELEVANCE This in-vitro study will help better understand the caries process and the impact of physical and chemical characteristics of enamel on de- and remineralization challenges

Functionalisable cyclopolymers by ring-closing metathesis

Post‐polymerisation modification of polymers is extremely beneficial in terms of designing brand new synthetic pathways toward functional complex polymers. While many chemical groups could provide a platform for chemical functionalisation, arguably one of the most versatile groups is the olefin functionality. This could be significant as the olefins do not readily interfere with common polymerisation techniques such as ring-opening polymerisation (ROP) but can be transformed into a broad range of functional groups. Ring-Closing Metathesis (RCM) is a powerful method for the preparation of cyclic compounds by the formation of new carbon-carbon double bonds. The aim of this project is utilising RCM as a post-polymerisation modification tool for preparing novel functionalisable cyclopolymers. This work includes monomer synthesis, ring-opening polymerisation and post-polymerisation modification. Whereas aliphatic polyethers are highly established polymers and used for an immense variety of applications, stereoregular cyclic architectures of polyethers mimic natural polymers remain rare in synthetic polymer chemistry. Herein we disclosed the formation of a stereocontrolled 1,4-linked six-membered functionalisable cyclopolyether (FCPE) prepared by RCM. Further post-polymerisation modification by diastereoselective dihydroxylation (DH) afforded a novel polymer family encompassing a poly(ethylene glycol) backbone and sugar-like functionalities “PEGose”. The high stereoregularity of FCPE and PEGose produced helical conformation structures. In particular, (R,R) cis PEGose structure has an extended pseudohelical structure similar to amylose. Different ring sizes of cyclopolyethers were sought from two other different starting polymers; poly(epoxy-hexene) (PEH) and poly(divinyl-oxirane) (PDVO). While divinyl oxirane (DVO) and epoxy hexene (EH) were successfully polymerised by ROP, the RCM of PEH gave mainly a cross-linked polymer. The project also attempted to expand the principle to polyesters to afford 1,4-linked six-membered functionalisable cyclopolyesters. To have the desired structure, a novel polymer of poly(vinyl glycolic acid) (PVGA) was made by ROP of a new monomer, 5-vinyl-1,3-dioxolan-4-ones (vinyl-Dox), using an aluminium salen catalyst system. However, the RCM of the last polymer was not completed even after two days of the reaction and gave mainly a cross-linked polymer. Finally, in a collaborative project, ROP of L-thionolactide was reported for the first time using aluminium salen catalysts. The polymerisation was controlled, regioselective and completed within a few hours

Offline Signature Biometric Verification with Length Normalization using Convolution Neural Network

تواقيع اليدوية الصورية هي نوع من انواع البايومتري التصرفي الذي يعتمد على الصور. المشكلة هي في دقة تمييز التواقيع وتأكيديها وسبب انه عندما يوقع الشخص نادرا ما يوقع نفس التوقيع مرة ثانية بالضبط. وهذه المشكلة تسمى التقلب داخل المستخدم.هذا البحث يهدف لتحسين دقة التمييز التواقيع الورقية. في هذه الورقة العلمية, الطريقة المقترحة تتم بواسطة عملية مساواة اطوال التواقيع و الرسم البياني للمشتقات الموجه لكي يتم تحسين دقة التمييز. بالنسبة لعمليات التاكيد, تقنية التعلم العميق باستخدام شبكات العصبية الألتفافية تم استغلالها لعمليات التعليم والفحص. حيث تم اجراء تجارب باستخدام 4000 توقيع حقيقي و 2000 توقيع مزور بصورة احترافية حيث تم تجميع هذه التواقيع من 200 شخص ماليزي ووضعها في قاعدة بيانات اسمها "سكما" والتي هي متوفرة على المنصات الالكترونية للاستخدام العام. تم استخراج نتائج التجارب من خلال الخطئين وهما نسبة القبول الخاطئ وكان 4.15% والخطئ المسمى نسبة الرفض الخاطئ ونسبته مختبريا 1.65%.  والنسبة الدقة النهائية لقاعدة البيانات سكما هي 97.1%. وايضا في هذه الورقة العلمية تم مقارنة الطريقة المقترحة مع الطرق المتوفرة موخرا و التي تم اعتماد نفس قاعدة البيانات سكما لغرض المقارنة وتبين أن نسبة تميز التواقيع بالطريقة المقترحة تتفوق على الذي متوفر حاليا باستخدام نفس قاعدة البيانات سكما.Offline handwritten signature is a type of behavioral biometric-based on an image. Its problem is the accuracy of the verification because once an individual signs, he/she seldom signs the same signature. This is referred to as intra-user variability. This research aims to improve the recognition accuracy of the offline signature. The proposed method is presented by using both signature length normalization and histogram orientation gradient (HOG) for the reason of accuracy improving. In terms of verification, a deep-learning technique using a convolution neural network (CNN) is exploited for building the reference model for a future prediction. Experiments are conducted by utilizing 4,000 genuine as well as 2,000 skilled forged signature samples collected from 200 individuals. This database is publicly distributed under the name of SIGMA for Malaysian individuals. The experimental results are reported as both error forms, namely False Accept Rate (FAR) and False Reject Rate (FRR), which achieved up to 4.15% and 1.65% respectively. The overall successful accuracy is up to 97.1%. A comparison is also made that the proposed methodology outperforms the state-of-the-art works that are using the same SIGMA database

The influence of hardness and chemical composition on enamel demineralization and subsequent remineralization

Objectives The objectives were to investigate the hardness and chemical composition of sound, demineralized and pH-cycled bovine enamel and determine their influence on demineralization and remineralization behavior. Methods Ninety-four, 5 × 5 × 2-mm bovine enamel specimens were demineralized using three different times [(24 h (n = 33), 48 h (n = 30), 96 h (n = 31)]. The specimens were then pH-cycled using either 367 ppm F sodium fluoride or deionized water. Knoop hardness (HK) and energy-dispersive X-ray spectroscopy (measured elements: Ca, P, F, C, Mg, N) were performed at three stages (sound, after demineralization, after pH-cycling) and transverse microradiography was performed after demineralization and pH-cycling. Comparisons were determined by ANOVA. Results Results showed that HK, integrated mineral loss and lesion depth were significantly different between stages, demineralization times and treatments. The weight% of F at the surface was significantly affected by treatment, irrespective of demineralization time, while the Ca:P ratio of the enamel remained stable even after de- and remineralization protocols. The F in fluoride groups and the artificial saliva in non-fluoride groups were both able to induce enamel remineralization, indicating the protective effect of salivary pellicle against demineralization even in the absence of fluoride. Conclusions Harder specimens and those with greater surface F weight% were less susceptible to demineralization and were more likely to remineralize. However, the amount of surface Ca and P did not influence de- or remineralization behavior

Correlation between Micronutrient plasma concentration and disease severity in COVID-19 patients

Objectives: Coronavirus Disease 2019 (COVID-19) is caused by a new strain of betacoronavirus called SARS-CoV-2, which leads to mild to severe symptoms. Micronutrients in blood serum, namely, zinc, iron, copper, and selenium, play essential roles in the human body’s various organs. This study investigates the association between micronutrient levels and the severity of symptoms in SARS-CoV-2 infected patients.Methods: A cross-section study was conducted during June–August 2020 in Riyadh city among 80 patients with confirmed SARS-CoV-2 infection. Within 24 hours of hospital admission, patients have been divided into non-severe and severe cases, and blood samples were drawn from each patient to measure the serum levels of copper, iron “in the form of ferritin,” selenium, and zinc.Results: In both study groups, the mean copper and selenium serum levels were within the normal range, while the mean zinc and iron serum levels were elevated. A statistically significant difference was recorded between non-severe and severe cases regarding serum levels of iron and selenium (331.24 vs. 1174.95 ng/ml and 134 vs. 162 mcg/L, respectively, P < 0.0001). On the other hand, no significant difference was detected between both studied groups regarding serum level of zinc and copper (124.57 vs. 116.37 mcq/L and 18.35 vs. 18.2 mcmol/ L, respectively, P > 0.05).Conclusions: There was a significant elevation of selenium and iron serum levels among severe cases compared to non-severe cases of COVID-19. High levels of iron and selenium could be correlated with the disease severity during infection with SARS-CoV-2

Microhardness and friction coefficient of multi-walled carbon nanotube-yttria-stabilized ZrO2 composites prepared by spark plasma sintering

Multi-walled carbon nanotubes (eight walls) are mixed with an yttria-stabilized ZrO2 powder. The specimens are densified by spark plasma sintering. Compared to ZrO2, there is a 3.8-fold decrease of the friction coefficient against alumina upon the increase in carbon content. Examinations of the friction tracks show that wear is very low when the carbon content is sufficient. Exfoliation of the nanotubes due to shearing stresses and incorporation of the debris into a lubricating film over the contact area is probable

Evaluation the effect of high and low viscosity Nano-hydroxylapatite gel in repairing of an induced critical-size tibial bone defect in dogs: Radiolographical study

Many types of bioactive materials are categorized as bone tissue substitutes for reconstruction and regeneration of bone defects, such as nano-hydroxyapatite. The objective of the present study was to radiologically evaluate the bone healing process in experimentally induced tibial defects in dogs treated with two different viscosity concentrations of nano-hydroxyapatite gel. Twelve adult, healthy Mongrel dogs were included. A critical size bone defect of 3–0.7 cm was induced surgically in the lateral border of the tibial bone of the right limb of all dogs enrolled in this study. The dogs were then categorized into two treatment groups: Group 1 (6 dogs): The defect was filled with prepared hydroxyapatite nanogel at a concentration of 33%, and Group 2 (6 dogs) hydroxyapatite nanogel at a concentration of 24% was used as a filling material. The healing process of the tibial defect and associated clinical and radiolographical findings were recorded in all studied groups at 30 and 60 days postoperatively. The results of the current study showed complete healing of the induced defect in the absence of any signs of pain or discomfort. Radiographically, there was an increase in radiographic density in the first group at 60 days. There is continuing healing in the late stage of the bone segment with the surrounding area and a crossing callus with cortical irregularities, denoting a chronic periosteal reaction and a good healing process. In the second group, the defect was completely filled with cortical thickening, which appears denser, denoting a periosteal reaction. In conclusion, using hydroxyapatite nanogel with high viscosity as a bone substitute contributed to progressing bone tissue regeneration with good callus formation and giving perfect mechanical support to defective bone