A decision aid model for the selection of appropriate payment and pricing systems for construction projects

Abstract unavailable please refer to PD

Optical biosensors

Continuous glucose monitoring facilitates the stringent control of blood glucose concentration in diabetic and intensive care patients. Low-cost, robust, and reusable continuous glucose monitoring systems that can provide quantitative measurements at point-of-care settings is an unmet medical need. Phenylboronic acids (PBAs) have emerged as synthetic receptors that can reversibly bind to cis-diols such as glucose molecules. The incorporation of phenylboronic acids in hydrogels offer exclusive attributes as the binding process with glucose induces Donnan potential that leads to osmotic pressure, resulting in volumetric changes in the hydrogel matrix. Optical glucose sensors based on PBA-functionalized hydrogels have emerged as strong candidates for commercialization; however, their complex and time-consuming fabrication process, and their bulky and expensive readouts methods made them undesirable for quantitative analyses. In this dissertation, optical hydrogel sensors have been developed and attached to contact lenses for continuous glucose detection in physiological conditions. A simple fabrication method was utilized, and smartphone technology was employed for recording the output signals. A 1D photonic structure was replicated on a PBA-functionalized hydrogel to function as a transducer and to improve the sensor performance. Upon binding glucose with boronate anions immobilized in the hydrogel matrix, a positive volumetric shift occurred modifying the periodic constant of the photonic structure, consequently its diffraction properties altered. A correlation has been established between the sensor’s periodic constant and glucose concentration in the range of 0-50 mM. The hydrogel sensor was attached to a soft commercial contact lens (ACUVUE) and was interrogated for glucose detection in artificial tears. The ambient light sensor of a smartphone captured the intensity of the laser diffracted signals and was correlated with glucose concentrations. The smart contact lens showed very short response time (3 s), and a saturation time of near 4 minutes in continuous monitoring conditions. However, a laser beam was necessary to interrogate the contact lens which is uncomfortable, and the frequent exposure might be harmful to the eye cornea. Alternatively, a novel transducer has been introduced to enable interrogating the smart contact lens by using a white light beam. Light diffusing microstructures (LDMs) have been introduced for the first time for the sensing applications. The LDMs can be considered as densely-packed microparticles of different shapes and dimensions which have the capacity to diffuse the polychromatic and monochromatic light in the forward and backward directions. The LDMs were imprinted on the glucose -responsive hydrogel to monitor the volumetric shift due to glucose complexation. The volumetric modification of the hydrogel upon glucose complexation induced a change in the dimensions and refractive index of the LDMs, resulting in a variation in the diffusion efficiency. The glucose sensor was attached to a commercial contact lens and a smartphone measured the optical output signals. The alternative transducer enabled interrogating the smart contact lens by a white light beam and retained on the simplicity of the fabrication and the readout methodology; however, the response time of the senor increased significantly. The proposed smart contact lenses can be considered as a non-invasive way for continuous glucose monitoring, and can detect many other biomarkers that are beneficial for medical diagnostic applications. For implantable and remote monitoring of glucose concentration, fiber optic probes have been developed. Fiber optics have inherent advantages such as immunity to electromagnetic interference, miniaturization, and small volumes of samples. These merits candidate them for biosensing applications; however, complexity of the manufacturing process, poor mechanical properties, unpracticality of the readout methodology have hindered their practical applications. We have developed fiber optic probes for glucose detection that overcome the limitations mentioned above. Capability of the LDMs to scatter/diffuse the incident light beam in the forward and backward directions was exploited. The glucose responsive hydrogel imprinted with the LDMs was attached to the tip of a multimode silica fiber. Swelling of the attached hydrogel led to a decrease in the refractive index of the LDMs, inducing a decrease in the light scattering angles. Whereas the numerical aperture of the optical fiber indicates the range of the angles of the incident rays those satisfy the total internal reflection condition. Accordingly, swelling the hydrogel attached to the fiber result in more incident rays fall within the accepted range of angles to be guided in the optical fiber. Hence, the optical power guided in the fiber increased with glucose concentration. The fabricated fiber probe was interrogated for glucose detection in transmission configuration and the smartphone was utilized to pick up the fiber’s signals. Also, the probe was tested in reflection configuration which is a more practical mode for implantable biosensing applications. The probe overcame some limitations of the existing probes such as interferometric, SPR, and fluorescent probes in terms of ease of the fabrication and the interrogation processes. Additionally, the probe showed high sensitivity, rapid response, and selectivity for glucose over lactate. The lactate interference was found to be ~ 0.1% in the physiological condition. Furthermore, biocompatible hydrogel fibers were introduced to prevent or reduce the immune reaction in the implantation sites. The probes were tested for glucose detection and showed similar response to that of silica fiber probes; however, they presented lower sensitivity which might be the result of a higher light loss in the hydrogel fiber. In order to emphasize the variety of applications of these novel fiber optic probes that we developed, two more probes were fabricated for alcohol detection and pH measurements. The alcohol probe showed real-time sensing of ethanol, propanol, and dimethyl sulfoxide with a response time in seconds and a saturation time around 60 s. Also, the pH probe showed high sensitivity and rapid response in the acidic region with a sensitivity near 20% pH-1. For medical applications, the pH sensor was attached to a biocompatible fiber optic and was tested for pH sensing in reflection configuration. The probe can be recommended for gastric pH detection. The fabricated optical fiber sensors may also have applications in wearable and implantable point-of-care and intensive-care continuous monitoring systems

Mapping multiplexing technique (MMT): a novel intensity modulated transmission format for high-speed optical communication systems

There is a huge rapid growth in the deployment of data centers, mainly driven from the increasing demand of internet services as video streaming, e-commerce, Internet Of Things (IOT), social media, and cloud computing. This led data centers to experience an expeditious increase in the amount of network traffic that they have to sustain due to requirement of scaling with the processing speed of Complementary metal–oxide–semiconductor (CMOS) technology. On the other side, as more and more data centers and processing cores are on demand, as the power consumption is becoming a challenging issue. Unless novel power efficient methodologies are innovated, the information technology industry will be more liable to a future power crunch. As such, low complex novel transmission formats featuring both power efficiency and low cost are considered the major characteristics enabling large-scale, high performance data transmission environment for short-haul optical interconnects and metropolitan range data networks. In this thesis, a novel high-speed Intensity-Modulated Direct-Detection (IM/DD) transmission format named “Mapping Multiplexing Technique (MMT)” for high-speed optical fiber networks, is proposed and presented. Conceptually, MMT design challenges the high power consumption issue that exists in high-speed short and medium range networks. The proposed novel scheme provides low complex means for increasing the power efficiency of optical transceivers at an impactful tradeoff between power efficiency, spectral efficiency, and cost. The novel scheme has been registered as a patent (Malaysia PI2012700631) that can be employed for applications related but not limited to, short-haul optical interconnects in data centers and Metropolitan Area networks (MAN). A comprehensive mathematical model for N-channel MMT modulation format has been developed. In addition, a signal space model for the N-channel MMT has been presented to serve as a platform for comparison with other transmission formats under optical channel constraints. Especially, comparison with M-PAM, as meanwhile are of practical interest to expand the capacity for optical interconnects deployment which has been recently standardized for Ethernet IEEE 802.3bs 100Gb/s and in today ongoing investigation activities by IEEE 802.3 400Gb/s Ethernet Task Force. Performance metrics have been considered by the derivation of the average electrical and optical power for N-channel MMT symbols in comparison with Pulse Amplitude Modulation (M-PAM) format with respect to the information capacity. Asymptotic power efficiency evaluation in multi-dimensional signal space has been considered. For information capacity of 2, 3 and 4 bits/symbol, 2-channel, 3-channel and 4-channel MMT modulation formats can reduce the power penalty by 1.76 dB, 2.2 dB and 4 dB compared with 4-PAM, 8-PAM and 16-PAM, respectively. This enhancement is equivalent to 53%, 60% and 71% energy per bit reduction to the transmission of 2, 3 and 4 bits per symbol employing 2-, 3- and 4-channel MMT compared with 4-, 8- and 16-PAM format, respectively. One of the major dependable parameters that affect the immunity of a modulation format to fiber non-linearities, is the system baud rate. The propagation of pulses in fiber with bitrates in the order > 10G, is not only limited by the linear fiber impairments, however, it has strong proportionality with fiber intra-channel non-linearities (Self Phase Modulation (SPM), Intra-channel Cross-Phase Modulation (IXPM) and Intra-channel Four-Wave Mixing (IFWM)). Hence, in addition to the potential application of MMT in short-haul networks, the thesis validates the practicality of implementing N-channel MMT system accompanied by dispersion compensation methodologies to extend the reach of error free transmission (BER ≤ 10-12) for Metro-networks. N-Channel MMT has been validated by real environment simulation results to outperform the performance of M-PAM in tolerating fiber non-linearities. By the employment of pre-post compensation to tolerate both residual chromatic dispersion and non-linearity, performance above the error free transmission limit at 40Gb/s bit rate have been attained for 2-, 3- and 4-channel MMT over spans lengths of up to 1200Km, 320 Km and 320 Km, respectively. While, at an aggregated bit rate of 100 Gb/s, error free transmission can be achieved for 2-, 3- and 4-channel MMT over spans lengths of up to 480 Km, 80 Km and 160 Km, respectively. At the same spectral efficiency, 4-channel MMT has realized a single channel maximum error free transmission over span lengths up to 320 Km and 160 Km at 40Gb/s and 100Gb/s, respectively, in contrast with 4-PAM attaining 240 Km and 80 Km at 40Gb/s and 100Gb/s, respectively

Mapping multiplexing technique (MMT): a novel intensity modulated transmission format for high-speed optical communication systems

There is a huge rapid growth in the deployment of data centers, mainly driven from the increasing demand of internet services as video streaming, e-commerce, Internet Of Things (IOT), social media, and cloud computing. This led data centers to experience an expeditious increase in the amount of network traffic that they have to sustain due to requirement of scaling with the processing speed of Complementary metal–oxide–semiconductor (CMOS) technology. On the other side, as more and more data centers and processing cores are on demand, as the power consumption is becoming a challenging issue. Unless novel power efficient methodologies are innovated, the information technology industry will be more liable to a future power crunch. As such, low complex novel transmission formats featuring both power efficiency and low cost are considered the major characteristics enabling large-scale, high performance data transmission environment for short-haul optical interconnects and metropolitan range data networks. In this thesis, a novel high-speed Intensity-Modulated Direct-Detection (IM/DD) transmission format named “Mapping Multiplexing Technique (MMT)” for high-speed optical fiber networks, is proposed and presented. Conceptually, MMT design challenges the high power consumption issue that exists in high-speed short and medium range networks. The proposed novel scheme provides low complex means for increasing the power efficiency of optical transceivers at an impactful tradeoff between power efficiency, spectral efficiency, and cost. The novel scheme has been registered as a patent (Malaysia PI2012700631) that can be employed for applications related but not limited to, short-haul optical interconnects in data centers and Metropolitan Area networks (MAN). A comprehensive mathematical model for N-channel MMT modulation format has been developed. In addition, a signal space model for the N-channel MMT has been presented to serve as a platform for comparison with other transmission formats under optical channel constraints. Especially, comparison with M-PAM, as meanwhile are of practical interest to expand the capacity for optical interconnects deployment which has been recently standardized for Ethernet IEEE 802.3bs 100Gb/s and in today ongoing investigation activities by IEEE 802.3 400Gb/s Ethernet Task Force. Performance metrics have been considered by the derivation of the average electrical and optical power for N-channel MMT symbols in comparison with Pulse Amplitude Modulation (M-PAM) format with respect to the information capacity. Asymptotic power efficiency evaluation in multi-dimensional signal space has been considered. For information capacity of 2, 3 and 4 bits/symbol, 2-channel, 3-channel and 4-channel MMT modulation formats can reduce the power penalty by 1.76 dB, 2.2 dB and 4 dB compared with 4-PAM, 8-PAM and 16-PAM, respectively. This enhancement is equivalent to 53%, 60% and 71% energy per bit reduction to the transmission of 2, 3 and 4 bits per symbol employing 2-, 3- and 4-channel MMT compared with 4-, 8- and 16-PAM format, respectively. One of the major dependable parameters that affect the immunity of a modulation format to fiber non-linearities, is the system baud rate. The propagation of pulses in fiber with bitrates in the order > 10G, is not only limited by the linear fiber impairments, however, it has strong proportionality with fiber intra-channel non-linearities (Self Phase Modulation (SPM), Intra-channel Cross-Phase Modulation (IXPM) and Intra-channel Four-Wave Mixing (IFWM)). Hence, in addition to the potential application of MMT in short-haul networks, the thesis validates the practicality of implementing N-channel MMT system accompanied by dispersion compensation methodologies to extend the reach of error free transmission (BER ≤ 10-12) for Metro-networks. N-Channel MMT has been validated by real environment simulation results to outperform the performance of M-PAM in tolerating fiber non-linearities. By the employment of pre-post compensation to tolerate both residual chromatic dispersion and non-linearity, performance above the error free transmission limit at 40Gb/s bit rate have been attained for 2-, 3- and 4-channel MMT over spans lengths of up to 1200Km, 320 Km and 320 Km, respectively. While, at an aggregated bit rate of 100 Gb/s, error free transmission can be achieved for 2-, 3- and 4-channel MMT over spans lengths of up to 480 Km, 80 Km and 160 Km, respectively. At the same spectral efficiency, 4-channel MMT has realized a single channel maximum error free transmission over span lengths up to 320 Km and 160 Km at 40Gb/s and 100Gb/s, respectively, in contrast with 4-PAM attaining 240 Km and 80 Km at 40Gb/s and 100Gb/s, respectively

Three dimensional estimation of vegetation moisture content using dual-wavelength terrestrial laser scanning

PhD ThesisLeaf Equivalent Water Thickness (EWT) is a water status metric widely used in vegetation health monitoring. Optical Remote Sensing (RS) data, spaceborne and airborne, can be used to estimate canopy EWT at landscape level, but cannot provide information about EWT vertical heterogeneity, or estimate EWT predawn. Dual-wavelength Terrestrial Laser Scanning (TLS) can overcome these limitations, as TLS intensity data, following radiometric corrections, can be used to estimate EWT in three dimensions (3D). In this study, a Normalized Difference Index (NDI) of 808 nm wavelength, utilized in the Leica P20 TLS instrument, and 1550 nm wavelength, employed in the Leica P40 and P50 TLS systems, was used to produce 3D EWT estimates at canopy level. Intensity correction models were developed, and NDI was found to be able to minimize the incidence angle and leaf internal structure effects. Multiple data collection campaigns were carried out. An indoors dry-down experiment revealed a strong correlation between NDI and EWT at leaf level. At canopy level, 3D EWT estimates were generated with a relative error of 3 %. The method was transferred to a mixed-species broadleaf forest plot and 3D EWT estimates were generated with relative errors < 7 % across four different species. Next, EWT was estimated in six short-rotation willow plots during leaf senescence with relative errors < 8 %. Furthermore, a broadleaf mixed-species urban tree plot was scanned during and two months after a heatwave, and EWT temporal changes were successfully detected. Relative error in EWT estimates was 6 % across four tree species. The last step in this research was to study the effects of EWT vertical heterogeneity on forest plot reflectance. Two virtual forest plots were reconstructed in the Discrete Anisotropic Radiative Transfer (DART) model. 3D EWT estimates from TLS were utilized in the model and Sentinel-2A bands were simulated. The simulations revealed that the top four to five metres of canopy dominated the plot reflectance. The satellite sensor was not able to detect severe water stress that started in the lower canopy layers. This study showed the potential of using dual-wavelength TLS to provide important insights into the EWT distribution within the canopy, by mapping the EWT at canopy level in 3D. EWT was found to vary vertically within the canopy, with EWT and Leaf Mass per Area (LMA) being highly correlated, suggesting that sun leaves were able to hold more moisture than shade leaves. The EWT vertical profiles varied between species, and trees reacted in different ways during drought conditions, losing moisture from different canopy layers. The proposed method can provide time series of the change in EWT at very high spatial and temporal resolutions, as TLS instruments are active sensors, independent of the solar illumination. It also has the potential to provide EWT estimates at the landscape level, if coupled with automatic tree ii segmentation and leaf-wood separation techniques, and thus filling the gaps in the time series produced from satellite data. In addition, the technique can potentially allow the characterisation of whole-tree leaf water status and total water content, by combining the EWT estimates with Leaf Area Index (LAI) measurements, providing new insights into forest health and tree physiology.Egyptian Ministry of Higher Educatio

Dumping Syndrome: case series of uncommon incidence following Laparoscopic Sleeve Gastrectomy (LSG)

Introduction: Dumping syndrome (DS) is a clinical impediment characterized by postprandial discomfort following bariatric-surgery. Data on incidence of DS following LSG is scarce. The purpose of this case series is to demonstrate the observation of DS in Qatari patients following Laparoscopic Sleeve Gastrectomy (LSG). Methods: Cases from the outpatients’ clinic at the department of bariatric and metabolic surgery- Hamad General Hospital, who had undergone LSG during the year 2016 were followed up for progress and data were analyzed and treatment options were discussed. Results: Five women under the age of 45 were diagnosed with DS. The first patient experienced fatigue, weakness and syncope. The second patient had a chief complaint of mild dizziness and diarrhea associated with low blood sugar. The third patient had complaints of recurrent hypoglycemia characterized by sweating, tremors, palpitations and dizziness. The fourth patient experienced significant dizziness associated with eating sweat, fatigue and low blood sugar within the first 40 minutes after meal with symptoms being relieved temporarily by sugary food. The fifth patient was presented to the emergency department with severe hypoglycemia, severe hypokalemia, fatigue, nausea, food intolerance and abdominal cramps. The majority of patients had mild-moderate symptoms with only one case presenting with severe symptoms that required hospitalization (5th patient) as blood sugar was very low (36-45 mg%) with very low potassium (2-2.5 mmol). None of the 5 patients had any comorbidity. Of the five patients, the first 4 responded to the diet modification with 2 required adding Acarbose oral tablets to control their symptoms. The fifth patient with severe symptoms had to undergo more intense therapy to control the symptoms, including administration of intravenous fluids, electrolytes correction, Acarbose, Octreotide and symptomatic treatment for abdominal pain and nausea as well as the usual diet modification and nutritional supplement. Conclusion: DS in post-LSG patients is an uncommon condition that may lead to serious deficiency complications such as hypoglycemic attacks. This is yet another example that highlights the importance of patient education prior to discharge. Patients education should focus on raising the awareness of such potential complications and healthcare providers must have the knowledge and expertise to predict and deal with such ailment. While it is strongly recommended that alternative diets are adopted to help with the recovery of afflicted patients, severe cases of DS may require medication to treat critical cases.Hamad Medical Corporatio

The effect of protein supplementation on body muscle mass and fat mass in post-bariatric surgery: a randomized controlled trial (RCT) study protocol.

Severe weight loss through means of bariatric surgery has been associated with loss of muscle mass due to lack of absorption of protein. The aim of this RCT is to investigate the effectiveness of protein supplementation in reducing the risk of developing protein malnutrition and muscle wasting in post-bariatric surgery patients in Qatar. The study was based at the Department of bariatric and metabolic surgery, Doha metropolitan and regional areas. It is envisaged that approximately 160 post-bariatric surgery patients will be randomized and followed up for 6 months. These will be males and females obese (BMI >35) Qatari patients between the aged 18-60 years. Subjects with renal or liver disease and those with past history of bariatric surgery will be excluded. By the completion of the trial, patients who took less than 80% of the supplement will be further excluded from the final analysis. Protein supplement (Cubitan,Protein, Nutricia, Netherlands) that contain daily intake of 20 g of protein to be taken orally 3 times a day throughout the study period. The placebo group will receive identical ampule containing zero-protein with exact instructions as per the intervention group. Body weight, muscle and fat mass, total protein, albumin, vit B12, Magnesium and Zinc will be measured at baseline and every follow up/study visit. Study variables will be compared between the 2 groups at different stages of the trial, including baseline, using Sample T-test (paired and unpaired) and the significance level will be confirmed with the 95% confidence interval with alpha error set to 0.05. Protein supplementation for post-bariatric patients is not yet a standard procedure at Hamad Medical Corporation in Qatar and requires an RCT to establish evidence-based clinical practice guidelines. This study was approved by the Hamad Medical Corporation IRB and MRC committees (approval no. 16433/16). ClinicalTrials.gov NCT03147456 (registration date: 18 April 2017). One major strength of our study is that our population is a distinctive population (Qatari Obese patients) where results from international studies may not apply to the local and unique context. A local study like ours will provide healthcare providers in Qatar an opportunity to ensure good clinical practice and healthy and sustainable weight loss following bariatric surgery.The well-designed double-blinded RCT will almost certainly provide us with the evidence-based clinical practice guideline that we seek as health professionals.One limitation of our study is the slight discrepancy in caloric content of the intervention and the placebo (250 cal and 100 cal, respectively). However, it is the intervention that has the higher caloric content, in which case it may not influence the results in the direction of our hypothesis that protein supplementation leads to lower fat mass and higher muscle mass.Another limitation is that the use of the intervention and the placebo are not objectively measured. However, all efforts will be made to ensure compliance and reporting of consumption of products.A third limitation could be loss to follow up. Participants may cease to participate, particularly, once they have lost "sufficient' weight and gained the fitness to consume any type of foods they desire. This is common in late stages of post-bariatric surgery (beyond 3 months). We feel that this may be a challenge, particularly in reference to our specific population. However, such findings albeit negative, should serve in improving the clinical practice delivered by healthcare providers

The Effect of Protein Supplementation on Body Muscle Mass and Fat Mass in Qataris PostBariatric Surgery: A Randomized Controlled Trial RCT

Background and objectives: Obesity is a chronic medical condition characterized by an accumulation of excess fat in the body that may lead to negative health consequences. Bariatric surgery has been shown to be the most effective type of interventions to achieve and sustain significant weight loss in morbidly obese people. The objective of this study was to examine the effectiveness of protein supplementation in reducing the risk of developing protein malnutrition and low muscle mass, in post-bariatric patients in Qatar. Methodology: This study is a double-blinded randomized control trial. Recruitment of participants began in early 2017 following the ethical approval of the trial (HMC IRB approval no. 16433/16). The intervention group received protein supplement that contain 20 g of protein while the placebo group received zero protein supplement. All participants were followed up for 1 month post-surgery. Randomization was done on a weekly basis within blocks of 8 or 10 patients. Independent Sample-T Test and Paired Sample-T Test were performed to assess the effect of the intervention. Results: The mean weight loss in the control group was 9.6 kg, while the intervention group mean weight loss was 10.7 kg (p = 0.03). Change in muscle mass percentage was +0.50% in the placebo group, and +2.3% in the intervention group (P = 0.149). Fat percentage change in the placebo group was − 1.6% and − 2.6% in the intervention group (P = 0.153). The percentage change in Albumin in the placebo group was 2.76% and 9.71% in the intervention group (P = 0.031). Conclusion: Our study has confirmed findings from multiple studies that protein supplementation in post-bariatric surgery patients is a successful intervention for healthy and balanced weight loss. This is yet another endorsement that surgery alone cannot put an end to obesity and must be combined with well-structured nutritional education so patients do not go back to their old habits and put the weight back on.qscienc

Deep learning enhances acute lymphoblastic leukemia diagnosis and classification using bone marrow images

Acute lymphoblastic leukemia (ALL) poses a significant health challenge, particularly in pediatric cases, requiring precise and rapid diagnostic approaches. This comprehensive review explores the transformative capacity of deep learning (DL) in enhancing ALL diagnosis and classification, focusing on bone marrow image analysis. Examining ten studies conducted between 2013 and 2023 across various countries, including India, China, KSA, and Mexico, the synthesis underscores the adaptability and proficiency of DL methodologies in detecting leukemia. Innovative DL models, notably Convolutional Neural Networks (CNNs) with Cat-Boosting, XG-Boosting, and Transfer Learning techniques, demonstrate notable approaches. Some models achieve outstanding accuracy, with one CNN reaching 100% in cancer cell classification. The incorporation of novel algorithms like Cat-Swarm Optimization and specialized CNN architectures contributes to superior classification accuracy. Performance metrics highlight these achievements, with models consistently outperforming traditional diagnostic methods. For instance, a CNN with Cat-Boosting attains 100% accuracy, while others hover around 99%, showcasing DL models’ robustness in ALL diagnosis. Despite acknowledged challenges, such as the need for larger and more diverse datasets, these findings underscore DL’s transformative potential in reshaping leukemia diagnostics. The high numerical accuracies accentuate a promising trajectory toward more efficient and accurate ALL diagnosis in clinical settings, prompting ongoing research to address challenges and refine DL models for optimal clinical integration