bluuebunny/crossref_metadata_2025 huggingface dataset:
STIM1 phosphorylation in Xenopus oocytes during meiosis
Authors: Dib Maya , Machaca Khaled
Published: October 2012

Stromal interaction molecule 1 (STIM1), the ER calcium sensor, couples to Orai1, the calcium channel, and mediates store-operated calcium entry (SOCE). STIM1 localizes to the ER membrane. Following Ca²+ store depletion, STIM1 forms puncta that localize to the cortical ER and binds Orai1 to allow Ca²+ influx. The egg's competency to activate at fertilization is dependent on its ability to generate a fertilization-specific Ca2+ transient. This is achieved through remodeling of its calcium signaling machinery during oocyte maturation. Oocyte maturation is driven by kinase cascade including MOS- mitogen-activated protein kinase (MAPK) - maturation promoting factor (MPF). Coordinately, SOCE inactivates during maturation. This inactivation is due to internalizing of Orai1 and the inability of STIM1 to form puncta. Here we show that MPF phosphorylates STIM1. Through molecular and pharmacological manipulation we are able to differentially activate the kinases along the kinase cascade that drives oocyte maturation. STIM1 phosphorylation in these studies was monitored through a mobility shift on SDS-PAGE. When MPF is activated a mobility shift is observed. However, this is not the case when only Mos or the MAPK cascade were active. Our next step is to determine the role of MPF phosphorylation of STIM1, because previous studies have argued that phosphorylation does not inhibit STIM1 clustering during meiosis. Our data argue that MPF is the primary kinase that phosphorylates STIM1 during meiosis.
Photodynamic therapy for hair removal
Authors: Ali Mohamed , Zaher Amr , Ali Carmen , Al-Saad Khalid A.
Published: October 2012

Background:
Unwanted hair is one of the most common medical problems affecting women of reproductive age inducing a lot of psychological stress and threatening their femininity and self-esteem. Old methods of removing unwanted hair include shaving, waxing, chemical epilation, and electrolysis, all of which have temporary results. However laser-assisted hair removal is the most efficient method of long-term hair removal currently available. It is desirable to develop a reduced-cost photodynamic therapy (PDT) system whose properties should include high efficiency and low side-effects.

Objectives:
The aim is to develop an adequate PDT system including helium-neon (He-Ne) laser and its effect on the photodynamic activity of methylene blue (Figs. 1 and 2) in biological experiments.

Method:
Mice skin tissues were used in this study and divided into the following six groups: controls (Fig.3), free methylene blue (MB) incubation, liposomal MB incubation, laser without MB, free MB for 3 and 4 hrs and laser, liposome MB for 3 hrs and laser. MB was applied to wax epilated areas. The areas were irradiated with CW He-Ne laser system that emits orange-red light with wavelength 632.8 nm and 10 mW at energy density of 5 J/cm2 for 10 minutes. The UV-visible spectrum was collected by Cary spectrophotometer.

Results:
MB is selectively absorbed by actively growing hair follicles due to its cationic property (Fig.4). MB untreated sections showed that hair follicles and sebaceous glands are intact and there is no change due to the laser exposure (Fig.5). Free MB sections incubated for 3 hrs showed that He:Ne laser induced destruction in hair follicles, leaving an intact epidermis (Fig. 6). Treated section with free MB for 4 hrs showed degeneration and necrosis in hair follicles, leaving an intact epidermis (Fig. 7). Liposomal MB sections incubated for 3 hrs showed He:Ne laser induced destruction in hair follicles with intradermal leukocytic infiltration (Fig. 8).

Conclusion:
Low power He:Ne laser and MB offers a successful PDT system in selectively damaging hair follicles, leaving an intact epidermis. The current PDT system provides better outcome than hair destruction through laser heat transfer procedures and laser-mediated hair removal, due to complete destruction of hair follicles.
"Ca2+ funneling": Functional coupling between SOCE, SERCA and IP3 receptors enhances Ca2+ signaling efficiency in activating the Ca2+-activated Cl channels as downstream effectors.
Authors: Courjaret Raphael , MACHACA Khaled
Published: October 2012

Store-operated calcium entry (SOCE) is a ubiquitous Ca2+ influx pathway leading to a sustained, low amplitude Ca2+ signal that activates multiple physiological process including gene transcription and secretion, and contributes to store refilling. We here describe a novel mechanism, that we call "Ca2+ funneling", which allows efficient activation by SOCE of Calcium-activated chloride channels (CaCl2) in the xenopus oocyte to regulate the cell's membrane potential. When intracellular Ca2+ stores were emptied using ionomycin, a small CaCl2 current is observed. Conversely, when the stores were depleted following injection of IP3 there was a significantly larger CaCl2 activation than with ionomycin (2.5 ± 0.5 nA, n=14 vs 0.08 ± 0.02 nA, n=20). Surprisingly the size of the SOCE current was similar in both conditions, indicating that an equivalent calcium influx was leading to different CaCl2 activation. Ca2+ injection experiments ruled out any change in the CaCl2 sensitivity to Ca2+. The CaCl2 activated by IP3 could be inhibited by La3+, BTP-2, 2-APB and heparin showing its dependence on both store-operated channels as well as IP3 receptor activation. The same mechanism could also be induced when IP3 production was stimulated by lysophosphatidic acid (LPA). Moreover, we could show that the sustained phase of the biphasic depolarization induced by LPA required SOCE activation. Analysis of the cellular localization of the xenopus TMEM16a (CaCl2) and of the ER calcium sensor STIM1 revealed a tendency of the two proteins to exclude each other following store depletion. We therefore propose the existence of a functional coupling between SOCE, SERCA and IP3 receptors to effectively activate CaCl2 in response to an agonist-induced store depletion. We refer to this coupling as "Ca2+ funneling" where calcium entering the cell through SOCE is rapidly taken up into the ER by SERCAs and released through open IP3 receptors close to its target, the Ca2+-activated Cl channels.
A pilot study of diagnosed and undiagnosed type 2 diabetic patients in Qatar
Authors: Mook-Kanamori Dennis O , El-Din Selim Mohammed M , Mook-Kanamori Marjonneke J , Zirie Mahmoud A , Al-Homse Hala , Al-Obaidli Amina , Al-Mahmoud Khouloud A. S. , Rowe Jillian , Gerbi Wafaa , Chidiac Omar , Kader Sara A , Al Muftah Wadha , Takiddin Ahmad H , McKeon Cindy , Suhre Karsten
Published: October 2012

Background and Objectives:
The prevalence of type 2 diabetes (T2D) in Qatar is the highest in the world. It is estimated that about one quarter of the T2D patients in Qatar are still undiagnosed. We set out to examine determinants of pre-diabetes (PD) or undiagnosed T2D (UT2D). Furthermore, we examined risk factors for glucose regulation in patients with known T2D.

Methods:
We examined 178 patients with known T2D and 196 controls. Anthropometrics and HbA1c were measured. Socio-demographic (age, gender, ethnicity and educational level) and health information were assessed through questionnaires.

Results:
Twenty-six (13.3%) and twelve (6.1%) participants in the control group were PD and UT2D, respectively. Control participants from South Asian descent were at a greater risk of being PD or UT2D than Arab controls (Odds Ratio: 5.27 (95% confidence interval: 2.10, 13.22). Being obese was also associated with an increased risk of PD or UT2D (Odds Ratio: 2.94 (95% confidence interval: 1.31, 6.59). Of control participants from South Asian descent, 38% were actually PD or UT2D. In patients with known T2D, insulin use and a longer duration of T2D were both related to higher HbA1c levels (both p<0.0001). No socio-demographic factors were associated with glucose control in T2D.

Conclusions:
In a nation with a large South Asian immigrant population, we found a strong increased risk of being PD or UT2D in these subjects. Focus should be on the prevention and early identification in South Asian individuals. Larger studies are necessary to further examine the determinants of T2D and glucose regulation in Qatar.
Tunneling nanotubes mediate preferential transfer of mitochondria from endothelial to cancer cells and confer chemoresistance
Authors: Pasquier Jennifer , Guerrouahen Bella Samia , Ghiabi Pegah , Maleki Mahtab , Al Sulaiti Haya , Le Foll Frank , Rafii Arash
Published: October 2012

Many tumors are regulated by complex interactions with cellular components of the microenvironment including mesenchymal stem cells (MSC) or endothelial cells (ECs). While the role of receptor-ligand interaction at the cell surface is well documented, direct cell-to-cell contact has not been clearly established. Recently, tunneling nanotubes (TnTs) have been shown to support cell-to-cell transfer of organelles, various plasma membrane components and cytoplasmic molecules in several cell lines. We thus investigated the formation of TnTs between stromal cells and cancer cells supported by them. We demonstrate that TnTs occur between different cancer and stromal cell lines. TnTs formation seemed to be dependent of large membrane adhesion. We show that intercellular transfers of cytoplasmic content can occur by TnTs. However, we demonstrate that the exchange of mitochondria occurs preferentially between endothelial cells and cancer cells and contributes to chemoresistance. Our results point out the role of direct endothelial to cancer cell exchange, which emphasize our hypothesis that this angiogenesis-independent role of the endothelium plays a role in the constitution of the metastatic niche.
Biobank Qatar: Implementation and initial results
Authors: Riboli Elio , Elliott Paul
Published: October 2012

Biobank Qatar aims to establish a large national bioresource that will support the development of cutting edge medical research during the next decades. While the design of Biobank Qatar has similarities with other large-scale population-based prospective cohort studies established in other parts of the world, it is unique in the region and excels for its highly innovative scientific and technological features.

Biobank Qatar will include up to 80,000 healthy volunteers, who will be followed up during the next decades to investigate the major behavioral, genetic and environmental causes of the chronic diseases most prevalent in the Qatari population.

At the initial baseline visit the study participants will provide detailed information on lifestyle and medical history, a number of medical measurements will be made including ECG, spirometry, retinal image, pulse-wave velocity, anthropometric measurements, iDXA etc. Blood, urine and saliva samples will be collected, aliquoted and stored frozen for future investigations. A set of established clinical chemistry analyses (e.g. haematology, lipids, inflammation markers, hormones, nutrients) will be measured at baseline.

During 2011-2012, activities focused on the establishment of protocols, clinical and IT facilities. A unique feature of Biobank Qatar is the comprehensive, real-time IT integration of all the baseline measurements.

An initial test of the study protocol and clinical measurements was conducted December 2011 to May 2012 when 100 participants attended the biobank facilities at Hamad Medical City. Cooperation of the study participants was excellent. This initial sample provided helpful insights on some lifestyle and medical conditions. For example:
- Sedentary lifestyle is highly prevalent.
- High prevalence of participants having gained weight in a year.
- Diabetics have higher body mass index and larger waist circumference than non-diabetics.
- Short sleeping hours are associated with higher blood pressure.
- Physical activity, even at modest levels, is associated with lower blood pressure and smaller waist circumference.
These initial findings indicate feasibility of high quality data collection, and confirm well-known associations between lifestyle and metabolic features in the Qatari population. The initial test provides strong rationale for the extension of the Biobank to include large numbers of participants as planned.
Evidence for a cell fate refinement mechanism in sensory neurons
Authors: Abdus-Saboor Ishmail , Shykind Benjamin
Published: October 2012

The olfactory receptors (ORs), which are G-protein coupled receptors, number more than 1,000 and comprise the largest gene family in the mammalian genome. ORs are expressed both monogenically and monoallelically in olfactory sensory neurons (OSNs) and the mechanism that controls their regulation is largely unknown. ORs reside in constitutive heterochromatin and selection of one OR and from one allele occurs stochastically. To ensure singular monoallelic OR expression, a negative feedback mechanism is elicited by the first selected OR to suppress non-selected ORs in a given neuron.

Here we describe results for mice with a 'monoclonal' nose that express one OR, M71,in 95% of all mature OSNs. The M71 transgene suppresses expression of endogenous ORs, and remaining endogenous expression is mostly restricted to immature neurons in the olfactory epithelium. We show that the endogenous OR repertoire are expressed prior to suppression by M71 transgene expression, contrary to current models. When we introduced a second transgene into M71 mice that expressed another OR in most mature OSNs, OSNs uncharacteristically expressed both of the ORs. We hypothesize that unresolved OR competition compromised the neuron's ability to express only one receptor.

We further show that suppression of endogenous ORs by M71 is not reversible, and that M71 does not need to be continuously expressed for endogenous ORs to remain suppressed.

In these experiments, we have engineered OSNs to express more than one OR in an OSN at a time, which is normally a low probability event. We believe that these experiments reveal the existence of a backup pathway that ensures only one OR will be expressed per neuron. It is possible that mammals have evolved similar mechanisms in other examples of stochastic, monoallelic gene expression, such as in random X-chromosome inactivation or lymphocyte receptor expression.
Identification of molecular pathways implicated in the metastasis process in a mouse model of lung adenocarcinoma
Authors: Abdelkarim Mouaadh , Gerardine Supria , Marmar Rufayda , Kallas Omar , Massaeli Hamid , Mesaeli Nasrin
Published: October 2012

A global survey of cancer has shown that lung cancer is the most common cause of the new cancer cases and cancer deaths in both men and women worldiwide. In Qatar a recent retrospective study based on a cohort of patient registry of Al Amal Cancer Hospital from 1991-2006, showed that lung cancer and lumph node cancer are the major cancers in men (5.9%, incident rate per 100,000) while in women breast cancer had the highest incidence.

To study the mechanisms of lung cancer development we recently developed a transgenic mouse model overexpressing CRT under the control of Tie2-promotor. The main phenotype of these mice is the development of metastatic lung adenocarcinoma similar to human patients. The objectives of the current study was to identify the molecular pathways involved in the metastatic behavior of lung adenocarcinoma.

To examine our objectives we used anchorage independent and adherent culture of lung adenocarcinoma cells isolated from mouse and human cell lines. Using microarray and bioinformatic analysis we have identified several pathways and genes that are altered in mouse cells. The microarray analysis demonstrates that 90 genes are up-regulated and 66 genes are down regulated under anchorage-independent condition compared to adherent conditions.

The bioinformatic analyses demonstrate that the up-regulated genes are implicated in cellular development, cellular growth and proliferation pathways. These pathways include: VEGF signaling, bladder cancer signaling, VEGF family ligand-receptor interaction and Ephrin-receptor signaling. The bioinformatic analyses also demonstrate that the downregulated genes were implicated in cell cycle regulation and cell-to-cell signaling and interaction. The analysis of these genes by canonical pathawy demonstrate that these genes are involved in the regulation of very relevant pathaway implicated in cancer essentially : Hematopoeisis from multipotent stem cells, TGF-β signaling and tight junction signaling. We are currently examining these pathways in human adenocarcinoma cell line.

In conclusion, our data illustrate that although calreticulin is an endoplasmic reticulum calcium binding chaperone, it is involved in the process of tumor development and metastasis. Further work is needed to decipher the molecular mechanism of involvement of calreticulin in tumor development.

This research was funded by QNRF grants UREP09-084-3-016 and NPRP4-043-3-016.
Fuzzy-QFD approach to quality assurance in pediatric services in public and private hospitals in Qatar
Authors: Al-Shouli Hana Yousef , Faisal Mohd Nishat
Published: October 2012

Background and objectives:
This study was conducted to understand the dimensions important for quality assurance in pediatric services of public and private hospitals in Qatar.

Method:
The study employed Fuzzy- Quality Function Development (Fuzzy-QFD) approach to translate the patients expectations into appropriate service specifications and to perform assessments of the existing processes. The importance of this tool lies in its ability to improve customer satisfaction levels since its major role is the alignment of technical requirements on the basis of customer demands. In this study, patients who visited pediatric services were surveyed about their expectations from pediatric hospitals to develop the "WHAT" part of the Fuzzy-QFD model. Then a focus group consisting of three doctors, a nurse and one healthcare researcher was formed to identify appropriate service specifications and the existing processes available in pediatric hospitals in Qatar. The input from this group was used to develop the correlation matrix, which was an important step in the Fuzzy-QFD process. The matrix showing the relationship between the "WHAT's" and the "HOW's" seeks to match patients' expectations with the technical specifications of the services adopted by the hospitals.

Results and conclusions:
The final weight and ranking concluded that management should give prime importance to 1) continual survey of patients to assess their needs, 2) patients and family rights, 3) the quality of policy and procedures documentation, 4) in-service continuous education and training, 5) the management of nursing operations, 6) the Service Quality Program (quality and patient safety), and 7) the waiting and distribution systems.
Targeting microRNAs offers a new therapeutic approach for the treatment of diabetes-related cardiovascular disease
Authors: Omar Hala , Marei Isra , Arunachalam Gnanapragasam , Samuel Samson M. , Triggle Christopher , Ding Hong
Published: October 2012

Background and Objectives:
The World Health Organization states that cardiovascular disease is the leading cause of death worldwide. The increasing prevalence of obesity and diabetes indicate that cardiovascular disease will remain a major health concerns for decades to come. The Gulf States including Qatar, the Middle East and the North African (MENA) region as whole, but also elsewhere in the world, face a pandemic of obesity and diabetes. Hyperglycaemia is the common denominator of both type-1 and type-2 diabetes and results in "glucose toxicity" that is closely linked to the high cardiovascular morbidity and mortality associated with diabetes. A reduction in the generation of NO -an important contributor to the endothelium regulation of blood flow and coagulation- in response to hyperglycaemia, is an early indicator of the onset of vascular disease. NO bioavailability is determined through the balance of its generation by eNOS and its quenching by reactive oxygen species, ROS. In response to hyperglycaemia and a variety of metabolic perturbations, eNOS produces predominately superoxide anions rather than NO and there is therefore an increase in oxidative stress and reduced bioactivity of NO. MicroRNAs (miRs) are small non-coding RNAs that inhibit gene expression and have also been implicated in the regulation of endothelial cell biology. A number of miRs including 221 & 222 have been implicated in endothelial cell function. They are involved in post-transcriptional control of major regulatory pathways.

Methods:
Mouse microvascular endothelial cells (MMECs) were cultured in normal (11mM) or high glucose (HG, 40mM) media and the ratio of coupled (dimeric) to uncoupled (monomeric) eNOS determined by immunoblot. ROS, NO and the expression of miR-221/miR-222 were also measured.

Results:
HG enhanced ROS, reduced the eNOS dimer/monomer ratio and reduced the generation of NO. Our data indicate that HG-induced ROS generation can be reversed in the presence of inhibitors of miR-221/miR-222.

Conclusion:
Hyperglycemia is associated with increased oxidative stress and decreased NO bioavailability. miR-221 and miR-222 play an important role in high glucose-induced increased oxidative stress and endothelial dysfunction.
Point prevalence survey of antibiotic utilization in oncology patients
Authors: Ahmed Sara Hayder , Hammuda Arwa , Black Emily Kathleen , ElAzzazy Shereen
Published: October 2012

Background & Objectives
Point Prevalence Surveys (PPS) are used internationally for identifying antibiotic prescribing practices and evaluating antibiotic stewardship programs. The objectives of this study are to develop a PPS tool to be used in Qatar, to determine prevalence of antibiotic consumption in the National Center for Cancer Care and Research (NCCCR) inpatient population, and to characterize antibiotic prescribing practices. The secondary goal is to identify targets for antibiotic stewardship programs to improve prescribing practices.

Methods
A chart audit tool was designed based on the available literature and piloted for face validity. All adult inpatients receiving active systemic antibiotic prescriptions at 8:00AM on each audit day were surveyed. Data were collected on 3 separate days over a two week period from 26 April through 3 May 2012 at NCCCR. Collected data obtained from electronic and paper-based charts included: diagnosis, type, dose and frequency of antibiotics, route of administration, and duration of therapy. Further information such as compliance to the available local guidelines and microbiology results were also assessed.

Results
The overall prevalence of antibiotic use during the audit was 43% (25/58). A total of 33 antibiotics were prescribed to the 25 patients receiving systemic antibiotic therapy. An indication for antibiotic prescribing was documented in 80% (20/25) of patient charts, however, only 20% (5/25) reported duration of antibiotic therapy. The most frequently used antibiotics were Penicillin/β-lactamase inhibitor combinations 40% (13/33), followed by carbapenems 15% (5/33). In 2 out of 6 febrile neutropenic patients, local febrile neutropenia guideline was accurately implemented. Sixty one percent (20/33) of prescriptions complied with local antibiotic restriction guideline. Pre-therapy cultures were performed for 96% (24/25) of patients and all antibiotic choices matched results of available sensitivity tests performed for these patients.

Conclusions
The findings of this study demonstrate frequent antibiotic consumption in the immunocompromised population highlighting the importance of development, implementation, and expansion of antibiotic stewardship programs at NCCCR.
The effect of graded hypoxia on the development of neuromuscular fatigue during maximal intermittent dynamic leg extensions
Authors: Christian Ryan , Girard Olivier , Billaut Francois , Bishop David
Published: October 2012

Hypoxia has been shown to exacerbate the performance loss during Maximal Intensity Intermittent Exercise (MIIE). However, the effect of hypoxia on the development of central and peripheral mechanisms of fatigue during MIIE is unknown. The aim of the study is to explore the development of both central and peripheral fatigue during multiple bouts of MIIE under varying severity levels of hypoxia. On separate days, 14 healthy men performed four bouts of 6 x 5 maximal intensity, isokinetic leg extensions at 300°/s (15 s passive rest separating reps, 100 s separating sets) under normoxia (simulated altitude/fraction of inspired 02: 0m/0.21%), moderate (3000m/14.4%), and severe hypoxia (5400m/10.1%). Neuromuscular assessments which included electromyography and measurements of voluntary and evoked contractions of the knee extensors were conducted immediately pre and post each bout of exercise. Performance loss was dependent on the severity of hypoxia with a main effect of condition on the mean peak power during each bout of exercise (p<.005) and the percent decrement in mean peak power across each bout (normoxia; 2.9 ± 1.3 %, moderate hypoxia; 5.2 ± 1.5 %, severe hypoxia; 10.3 ± 2.0 %, p=<.01). Despite a main effect of time, the reduction in RMS activity was not different between conditions (-10.4% all conditions compounded). Maximal voluntary contraction force, % voluntary activation and potential twitch force (Q,tw,pot) all decreased across time (p=<.05), with the end exercise percent reduction in Q,tw,pot being greater in severe hypoxia compared to normoxia (41.3 ± 3.0 % v 28.0 ± 3.2 % p=<.05). In conclusion, performance decrements during maximal intermittent dynamic leg extensions are exacerbated by hypoxia and result from both central and peripheral adjustments. However, central adjustments do not appear to limit excessive development of peripheral fatigue below a critical threshold.
Screening for the Arab allele mutation in LDLR using molecular techniques among Bahrainis with hypercholesterolemia
Authors: Ali Ameena , Ali Ameena Muhammed , Shawar Said , Latiff Aishah , Alsayrafi Muhammad
Published: October 2012

Background:
Familial hypercholesterolemia (FH) is an autosomal dominant disorder caused by defects in LDLR and leads to the elevation of blood cholesterol levels. The worldwide prevalence of the disease is 1:500 and 1 in a million for heterozygous and homozygous respectively. Recently, the Arab allele has emerged as a potential founder mutation.

Objectives:
The aims of this study are to develop a rapid diagnostic assay to screen for the Arab allele.

Methods:
Using RFLP, ARMS-PCR, and High Resolution Melt (HRM) 150 hypercholesterolemic (HC) patients from Salmaniya Medical Complex (Bahrain) were screened for the presence of the Arab allele mutation in their genomic DNA. Positive and negative controls were always run along with the samples.

Results:
No mutations were found among the screened volunteers and the Arab allele was not detected in the samples screened using any of the techniques described.

Conclusion:
Feasibility of screening using RFLP, ARMS-PCR, and HRM as a rapid diagnostic assay for the Arab allele detection was demonstrated. These assays are cost-effective in comparison to sequencing of whole LDLR gene (18 exons and 17 introns) and should be considered as a priority for any screening protocol. Ultimately, screening for FH requires the construction of all known Arab-specific mutations in a chip.
The association of adiponectin gene polymorphism with gestational diabetes mellitus: The role of rs1501299 and rs2241766 variants
Authors: Rizk Nasser , Sharif Elham Abdul Latif M , Baloochi Sherin Mousa , Rahman Pour Atefah
Published: October 2012

Background:
Previous studies indicated changes of adiponectin levels during gestation. The adiponectin gene ADIPOQ is located on chromosome 3q27. The association of two single nucleotide polymorphisms (SNPs) (rs1501299 and rs2241766) in ADIPOQ gene with risk of gestational diabetes mellitus (GDM) was investigated among Arab pregnant women residing in Qatar.

Methods:
A case-control association study was performed on 115 pregnant women with GDM and 130 controls from Qatar. Genotypes were determined using TaqMan real time PCR assay. Fasting serum c-peptide, leptin and adiponectin levels were determined using Multiplex ELISA technique.

Results:
All SNPs were within the Hardy-Weinberg Equilibrium (HWE). The frequency distribution of the genotype 276 G-T (rs1501299) revealed that (40.9%), (45.6%), had GG and (53.0%), (44.0%) had GT, and (6.1%), (10.4%) had TT between GDM and control, respectively with P value= 0.261. The frequency distribution of the genotype 45T-G (rs2241766) revealed that (20.8%), (16.1%), had TT and (69.6%), (65.4%) had TG, and (9.6%), (18.5%) had GG between GDM and control, respectively with P value= 0.117. T and G alleles were the minor alleles for 276 G-T and 45T-G with a frequency of (0.11) and (0.22), respectively. Using recessive genetic model, the logistic regression analysis reveled that the Odds ratio and 95% CI was 2.14 (1.01-4.95), p=0.04 for 45T-G and was 1.79 (0.69-4.65), p=0.22 for 276 G-T. Serum c-peptide (ng/ml), and leptin (ng/ml) was significantly lower in subjects having GG versus TT+TG alleles of 45T-G with mean and SEM (7.6±1.8 Vs. 17.3 ±1.2, p= 0.002), and (21.5± 2.5 Vs. 42.1± 2.8, p=0.035). Similar significant findings were observed for TT versus TG+GG genotypes for SNP 276G-T. Adiponectin levels (µg/ml) were not significantly different in subjects having GG versus TG+TT genotypes for 45T-G and for TT versus TG+GG genotypes for 276G-T with mean and SEM (17.1± 1.8 vs. 17.2±2.3, p=0.892 and 16.5±3.24 Vs. 19.8 ±1.8, p= 0.478), respectively.

Conclusion:
GG carriers of 45T-G may increase the odds of getting GDM among Arab residents in Qatar. Decreased pancreatic secretory function (C-peptide) with increased adiposity (leptin) among GG carriers of 45T-G and TT carriers of 276GT may explain its roles in the development of GDM.
Non-invasive multiple camera calibration in highly crowded environments
Authors: Aldea Emanuel , Kiyani Khurom , Petrou Maria
Published: October 2012

Background:
Very dense crowds that exceed three people per square metre present many challenges in computer vision for efficiently measuring quantities such as density and pedestrian trajectories. An accurate characterisation of such dense crowds can improve existing models and help to develop better strategies for mitigating crowd disasters.

Pedestrian models used for tracking are often based on assumptions which are no longer valid in highly dense crowds, e.g. absence of occlusions. Recently, multiple camera systems with partially overlapping fields of view have been shown to offer critical advantages over other non-overlapping schemes.

Objectives:
We focus on overcoming the non-invasive aspect of the camera calibration, imposed by real crowded environments needed in order to accurately segment individuals. We will also underline the interdisciplinary challenges related to computer vision and real-time processing.

Methods:
Although there is an important amount of work devoted to multiple camera calibration, the automation of the process in specific environments remains challenging. In dense crowds, such as in Mecca, access to the site for calibration purposes or for adding support visual features is impossible. Moreover, the supervising role of the user for calibration scenarios is very important, and cumbersome for large camera networks. We investigate a light solution based on a coarse-to-fine estimation of the camera positions using both static and dynamic features. This highlights the necessary tradeoff between the crowd coverage, the purpose of the experiment, and the static feature distribution which is required to register the camera system properly. A more practical aspect that we underline is related to the importance of accurate time synchronization within the system in the presence of a dynamic scene.

Results:
We present a pilot study of the above scheme conducted at Regents Park Mosque in London on Friday when the mosque is particularly crowded. We have set up a distributed system of accurately synchronized Firewire cameras, acquiring high-resolution data at 8Hz. We will also aim to present some preliminary single camera studies of crowd flow using real-world data from the Muslim Hajj pilgrimage from 2011.
Track me to track us: Leveraging short range wireless technologies for enabling energy efficient Wi-Fi-based localization
Authors: Abdellatif Mohamed , Mtibaa Abderrahmen , Harras Khaled
Published: October 2012

Given the success of outdoor tracking via GPS and the rise of real-time context-aware services, users will soon rely on applications that require higher granularity indoor localization. This need is further manifested in countries like Qatar, where various social and business activities occur indoors. Wi-Fi-based indoor localization is one of the most researched techniques due to its ubiquitous deployment and acceptable accuracy for a wide range of applications. However, we do not witness such techniques widely deployed mainly due to their high demand on energy, which is a precious commodity in mobile devices.

We propose an energy-efficient indoor localization system that leverages peoples' typical group mobility patterns and short-range wireless technologies available on their devices. Our system architecture, shown in the figure, is designed to be easily integrated with existing Wi-Fi localization engines. We first utilize low-energy wireless technologies, such as Bluetooth, to detect and cluster individuals moving together. Our system then assigns a group representative to act as a designated cluster head that would be constantly tracked. The location of other group members can be inferred so long as they remain within proximity of the cluster heads. Afterwards, cluster heads continue to send the periodic received signal strength indicator (RSSI) updates, while the remaining members turn off their Wi-Fi interface relying on the cluster head to be localized. Our system is responsible for dynamically handling the merger or splitting of clusters as a result of mobility.

We implement a prototype of the system, and evaluate it at scale using the QualNet simulator. Our results show that we can achieve up to 55% energy reduction with a relatively small degradation in localization accuracy averaging 2 meters. This accuracy reduction is non-impactful given the typical applications expected to leverage our system.
Computational and statistical challenges with high dimensionality: A new method and efficient algorithm for feature selection in knowledge discovery
Authors: El Anbari Mohammed , Bensmail Halima
Published: October 2012

Qatar is currently building one of the largest research infrastructures in the Middle East. In this orientation, Qatar foundation has constructed a number of universities and institutes composed of highly qualified researchers. In particular, QCRI institute is forming a scientific computing multidisciplinary group with a special interest in machine learning, data mining and bioinformatics. We are now able to address the computational and statistical needs of a variety of researchers with a vital set of services contributing to the development of Qatar.

The availability of massive amounts of data and challenges from frontiers of research and development have reshaped statistical thinking, data analysis and theoretical studies. There is little doubt that high-dimensional data analysis will be the most important research topic in statistics in the 21st century. Indeed, the challenges of high-dimensionality arise in diverse ﬁelds of sciences, engineering, and humanities, ranging from genomics and health sciences to economics, ﬁnance, and machine learning and data mining. For example, in biomedical studies, huge numbers of magnetic resonance images (MRI) and functional MRI data are collected for each subject with hundreds of subjects involved. Satellite imagery has been used in natural resource discovery and agriculture, collecting thousands of high resolution images. Other examples of these kinds are plentiful in computational biology, climatology, geology and neurology among others. In all of these fields, variable selection and feature extraction are crucial for knowledge discovery.

In this paper, we propose a computationally intensive method for regularization and variable selection in linear models. The method is based on penalized least squares with a penalty function that is a combination of the minimum concave penalty (MCP) and an L2 penalty on successive differences between coefficients. We call it the SF-MCP method. Extensive simulation studies and applications to large biomedical datasets (leukemia and glioblastoma cancers, diabetes, proteomics and metabolomics data sets) show that our approach outperforms its competitors in terms of prediction of errors and identification of relevant genes that are responsible of some lethal diseases.
Hybrid pronunciation modeling for Arabic large vocabulary speech recognition
Authors: Elmahdy Mohamed , Hasegawa-Johnson Mark , Mustafawi Eiman
Published: October 2012

Arabic is a morphologically rich language. This morphological complexity results in a high out-of-vocabulary rate. That is why a lookup table for pronunciation modeling is not efficient for large vocabulary tasks. In previous research, graphemic modeling was proposed by approximating pronunciation modeling to be graphemes rather than actual phonemes. In this research, we have proposed a hybrid acoustic and pronunciation modeling approach for Arabic large vocabulary speech recognition tasks. The proposed approach benefits from both phonemic and graphemic modeling techniques, where two acoustic models are fused together. The hybrid approach also benefits from both vocalized and non-vocalized Arabic resources, which is useful because the amount of non-vocalized resources is always higher than vocalized ones. Two speech recognition baseline systems were built: phonemic and graphemic. The two baseline acoustic models were combined after two independent trainings to create a hybrid model. Pronunciation modeling was also hybrid by generating graphemic variants in addition to phonemic variants. Three techniques are proposed for pronunciation modeling: Hybrid-Or, Hybrid-And, and Hybrid-Top(n). In Hybrid-Or, either graphemic or phonemic modeling is applied for any given word. In Hybrid-And, a graphemic pronunciation is always generated in addition to existing phonemic pronunciations. Hybrid-Top(n) is a mixture of Hybrid-Or and Hybrid-And by applying Hybrid-Or on the top n high frequency words. Experiments were conducted in the large vocabulary news broadcast speech domain with a vocabulary size of 250K. The proposed hybrid approach has shown a relative reduction in WER of 8.8% to 12.6% depending on pronunciation modeling settings and the supervision in the baseline systems. In large vocabulary speech domains, acoustic and pronunciation modeling is a common problem among all Arabic colloquial varieties. Thus, for future work, the proposed approach is currently being extended and evaluated with different Arabic colloquial varieties (e.g. Qatari, Egyptian, Levantine, etc.). Moreover, the proposed technique can be applied with other morphologically rich languages like Turkish, Finnish, Korean, etc. This work was funded by a grant from the Qatar National Research Fund under its National Priorities Research Program (NPRP) award number NPRP 09-410-1-069. Reported experimental work was performed at Qatar University in collaboration with University of Illinois.
Aircraft scheduling on multiple runways
Authors: Rabadi Ghaith , Ghoniem Ahmed , Al-Salem Ameer , Kharbeche Mohamed , Hancerliogullari Gulsah , Shahrestanaki Farbod
Published: October 2012

Background:
Scheduling aircrafts on single or multiple runways is an important and difficult problem. This problem involves how aircrafts are sequenced on a runway and how they are assigned to runways has a significant impact on the utilization of the runways as well as on meeting the landing and departure target times. Most of the literature focuses on landing operations on a single runway as it is an easier problem to solve.

Objective:
This project was funded by Qatar Foundation to address the scheduling problem of both landing and departing aircrafts on multiple runways as they attempt to meet aircraft target times. The problem is further complicated when considering sequence-dependent separation times on each runway to avoid wake-vortex effects.

Methods:
This research project is based on a two-pronged approach. First, mathematical optimization models were developed to find optimal runway assignments and aircraft sequences on each runway. Due to the significant computational complexity of the problem, a second approach was developed to find near-optimal solution through the development of local search algorithms and metaheuristics, especially for larger problems.

Results:
Several optimization models were developed and the most effective one was selected to find solutions to the problem. The solution effectiveness was enhanced by developing valid inequalities to the mathematical program, which significantly reduced the computational time necessary to solve the problem. Optimal solutions were obtained for problem instances much more difficult than any accounted for in data of available literature. A scheduling index, local search algorithms and metaheuristics (Simulated Annealing and Metaheuristic for Randomized Priority Search-MetaRaPS) were also developed to solve the problem. The results show that optimal or near optimal solutions were obtained for all instances, and the value of the proposed approximate algorithms becomes more evident as the problem size increases.

Conclusions:
The research done in this project demonstrates that there is added value in assigning aircrafts to runways and sequencing them using more optimized methods than the most commonly used approach of first-come-first-served. This research has the potential to change how airports schedule aircrafts in order to increase the runway utilization and better meet the landing and departing target times.
OPERETTA: An optimal deployable energy efficient bandwidth aggregation system
Authors: Habak Karim , Harras Khaled , Youssef Moustafa
Published: October 2012

The widespread deployment of varying networking technologies, coupled with the exponential increase in end-user data demand has led to the proliferation of multi-interface enabled devices. To date, these interfaces are mainly utilized independently based on network availability, cost, and user choice. While researchers have focused on simultaneously leveraging these interfaces by aggregating their bandwidths, these solutions however, have faced a steep deployment barrier and only focused on maximizing throughput while overlooking the energy awareness which is critical for mobile devices.

We therefore developed OPERETTA, shown in Figure1, an optimal deployable energy efficient bandwidth aggregation system for mobile users. Our system does not require modifications to applications, legacy servers, network infrastructure, or client kernel. If legacy servers choose to adopt our system, however, OPERETTA dynamically leverages this to achieve higher performance gains. OPERETTA is built as a middle-ware that is responsible for scheduling various connections and/or packets to different interfaces. This middleware estimates application and network interface characteristics and utilizes these estimates to take the most appropriate scheduling decisions. We formulate our scheduling problem as a mixed integer programming problem that has a special structure allowing it to be efficiently solved. This formulation allows users to achieve a desired throughput with minimal energy consumed.

We evaluate OPERETTA via prototype implementation on the Windows OS, as well as via simulation, and compare the results to the optimal achievable throughput and energy consumption. Our results show that, with no changes to the current legacy servers, OPERETTA can achieve up to 150% enhancement in throughput as compared to the current operating systems, with no increase in energy consumption. In addition, with only 25% of the servers being OPERETTA-enabled, the system performance reaches the throughput upper-bound. We ultimately demonstrate that OPERETTA achieves the goals of being optimal, energy-efficient, as well as easily and incrementally deployable.
Extending the reach of social-based context-aware ubiquitous systems
Authors: Abed Rabbou Dania , Mtibaa Abderrahmen , Harras Khaled
Published: October 2012

The proliferation of mobile devices equipped with communication technologies such as WiFi, 3G, and 4G, coupled with the exponential growth of online social networking, have increased the demand for social-context-aware systems. These systems leverage social information provided by users with contextual awareness, particularly location, to provide real-time personalized services. With Euromonitor International indicating a 37.7 % growth in mobile phone penetration in the past five years--ICTQatar recently reporting that each household owns 3.9 devices on average--Qatar is positioned as a strong candidate not only for the consumption of such services, but also for researching, building, and testing solutions related to context-aware system challenges.

We address some of these challenges and propose pragmatic solutions. Our contributions fall into the following two categories:

(i) We design and implement SCOUT, a context-aware, ubiquitous system that enables real-time mobile services by providing contextually relevant information. This information can either be generated reactively based on user request, or proactively created and disseminated to potentially interested users. Our SCOUT prototype consists of an android-based mobile client interfacing with facebook's API and a load-balancing profile-matching server that interacts with a localization engine.

(ii) Since mobile users may not all experience reliable mobile-to-core connectivity due to contention, cost, or lack of connectivity, we therefore extend the reach of context-aware services to disconnected mobile users by proposing a novel communication paradigm that leverages opportunistic communication. We first send the intended information to the smallest subset of connected users deemed sufficient to reach the disconnected destinations. This subset then selectively forwards, based on social profiles, this information to nodes that are more likely to meet the destinations. Our evaluation, via simulation, shows that our algorithm achieves an improvement of 25% to 80% compared to current communication paradigms, while reducing overhead by as much as 50%.

With SCOUT currently operational, and based on the simulation results, our ongoing work includes integrating our communication paradigm into the real system. We are also working on integrating real-time group recommender systems that identify groups based on user location coupled with social information to provide real-time contextual group recommendations.