Opto-VLSI-Based reconfigurable free space optical interconnects architecture

This paper presents a short-distance reconfigurable high-speed optical interconnects architecture employing a Vertical Cavity Surface Emitting Laser (VCSEL) array, Opto-very-large-scale-integrated (Opto-VLSI) processors, and a photodetector (PD) array. The core component of the architecture is the Opto-VLSI processor which can be driven by digital phase steering and multicasting holograms that reconfigure the optical interconnects between the input and output ports. The optical interconnects architecture is experimentally demonstrated at 2.5 Gbps using high-speed 1×3 VCSEL array and 1×3 photoreceiver array in conjunction with two 1×4096 pixel Opto-VLSI processors. The minimisation of the crosstalk between the output ports is achieved by appropriately aligning the VCSEL and PD elements with respect to the Opto-VLSI processors and driving the latter with optimal steering phase holograms

Archaeological evidence of Hellenistic impact in the Arabian Peninsula

Previous archaeological work in eastern Arabia has uncovered significant evidence for the cultural role which this region played in the ancient world, especially during the Iron Age. However, it seems that archaeologists overlooked the region. Therefore, one of the objectives of this research was to investigate in greater depth the extent of Greek influence on the eastern region of Arabia and to determine the results of this influence. My research also aims to redirect attention to some important sites that have been subjected to looting since the 1960s due to lack of security. To reach my goals, I first started in Chapter 1 with a brief historical and archaeological survey to get a general picture of what was happening near our study area, especially in Mesopotamia, from the beginning of the first millennium BC until the Hellenistic era. In Chapter 2, I also took a close look at the results of the discoveries at sites in the Arabian Gulf from the 1st millennium BC, especially those of Hellenistic date. This was followed by field work, including an archaeological survey in of the sites of Kanzan, Geriyah, and Ras Geriyah , are the sites where further research was needed in Chapter 3, as well as in Chapter 4 re-visits to some museums in Saudi Arabia. My results both corroborated previous studies and provided new information which confirmed that more attention should be paid to these sites. At Geriyah in particular locations were revealed which that need more extensive study than practical within the framework of my research. Finally, the last two chapter (Ch.5 and Ch.6) I have reviewed the most important results of the cultural relationship between the Arabs and the Greeks after Alexander the Great, especially in the economic field, in which the Gerrhaeans played an important role. Accordingly, I have discussed the location of Gerrha and its relation to Geriyah, the most likely site to be ancient Gerrha. Although it is important to find Gerrha, it is even more important to draw the attention of the authorities and archaeologists to Geriyah, to protect what remains of it, as previously it was left vulnerable to looting

An association between Helicobacter pylori infection and cognitive function in children at early school age: a community-based study

<p>Abstract</p> <p>Background</p> <p><it>H. pylori </it>infection has been linked to iron deficiency anemia, a risk factor of diminished cognitive development. The hypothesis on an association between <it>H. pylori </it>infection and cognitive function was examined in healthy children, independently of socioeconomic and nutritional factors.</p> <p>Methods</p> <p>A community-based study was conducted among 200 children aged 6-9 years, from different socioeconomic background. <it>H. pylori </it>infection was examined by an ELISA kit for detection of <it>H. pylori </it>antigen in stool samples. Cognitive function of the children was blindly assessed using Stanford-Benit test 5^thedition, yielding IQ scores. Data on socioeconomic factors and nutritional covariates were collected through maternal interviews and from medical records. Multivariate linear regression analysis was performed to obtain adjusted beta coefficients.</p> <p>Results</p> <p><it>H. pylori </it>infection was associated with lower IQ scores only in children from a relatively higher socioeconomic community; adjusted beta coefficient -6.1 (95% CI -11.4, -0.8) (P = 0.02) for full-scale IQ score, -6.0 (95% CI -11.1, -0.2) (P = 0.04) for non-verbal IQ score and -5.7 (95% CI -10.8, -0.6) (P = 0.02) for verbal IQ score, after controlling for potential confounders.</p> <p>Conclusions</p> <p><it>H. pylori </it>infection might be negatively involved in cognitive development at early school age. Further studies in other populations with larger samples are needed to confirm this novel finding.</p

The association between conditioned pain modulation and manipulation induced analgesia in people with lateral epicondylalgia

Objectives: Conditioned Pain Modulation (CPM) and Manipulation Induced Analgesia (MIA) may activate similar neurophysiological mechanisms to mediate their analgesic effects. This study assessed the association between CPM and MIA responses in people with lateral epicondylalgia (LE). Methods: Seventy participants with LE were assessed for CPM followed by MIA. A single assessor measured pressure pain thresholds (PPT) before, during, and after cold water immersion (10°C) of the asymptomatic hand and contralateral lateral glide (CLG) mobilization of the neck. For analyses, linear mixed models evaluated differences in CPM and MIA responses. Pearson partial correlations and regression analyses evaluated the association between CPM and MIA PPT. Results: There was a significant increase (CPM and MIA p<0.001) in PPT from baseline during the interventions (CPM mean 195.84 kPa elbow and 201.87 kPa wrist. MIA mean 123.01 kPa elbow 126.06 kPa wrist) and post the interventions (CPM mean 126.06 kPa elbow, 114.24 kPa wrist, MIA mean 123.50 kPa elbow, 122.16 kPa wrist). There were also significant moderate and positive partial linear correlations (r: 0.40–0.54, p<0.001) between CPM and MIA measures, controlling for baseline measures. Regression analyses showed that CPM PPT was a significant predictor of MIA PPT (p<0.001) and the models explained between 73% and 85% of the variance in MIA PPT. Discussion: This study showed that CPM and MIA responses were significantly correlated and that the CPM response was a significant predictor of MIA response

The nature and role of trap states in a dendrimer-based organic field-effect transistor explosive sensor

We report the fabrication and charge transport characterization of carbazole dendrimer-based organic field-effect transistors (OFETs) for the sensing of explosive vapors. After exposure to para-nitrotoluene (pNT) vapor, the OFET channel carrier mobility decreases due to trapping induced by the absorbed pNT. The influence of trap states on transport in devices before and after exposure to pNT vapor has been determined using temperature-dependent measurements of the field-effect mobility. These data clearly show that the absorption of pNT vapor into the dendrimer active layer results in the formation of additional trap states. Such states inhibit charge transport by decreasing the density of conducting states. (C) 2013 AIP Publishing LLC

Interleukin (IL)-17A and IL-17F and asthma in Saudi Arabia: mRNA transcript levels and gene polymorphisms

Asthma is a multifactorial disorder and both genetic and environmental factors contribute to its development. The present study explored cytokines interleukin (IL)-17A and IL17F levels as usable parameters for the diagnosis of asthmatics Saudi patients. Blood samples were collected from 100 asthma patients and 100 matched controls. The transcript mRNA levels in whole blood were determined by real-time reverse-transcription polymerase chain reaction. Expression studies showed that levels of IL17A and IL17F were significantly higher in asthma patients compared to controls [IL17A: 1.112 (2.088) vs 0.938 (1.363)]; IL17F: 0.707 (1.33) vs 0.667 (0.590). The mRNA transcripts of IL17A and IL17F were positively and significantly correlated in all subjects examined in this study: controls as well as asthma patients (r = 0.455, P &lt; 0.01 for controls and r = 0.644, P &lt; 0.01 for patients). These findings suggest that asthma is characterized by an elevation of cytokines IL17A and IL17F and the measurement of their expression can be a valuable parameter for the diagnosis of asthma.Keywords: Asthma, interleukin-17F (IL17F), interleukin-17A (IL17A), gene expression, real time-polymerase chain reaction (RT-PCR), Saudi Arabia.African Journal of Biotechnology Vol. 12(23), pp. 3615-362

Stem cell factor and its soluble receptor (c-kit) in serum of asthmatic patients- correlation with disease severity

<p>Abstract</p> <p>Background</p> <p>SCF (stem cell factor) is a pleiotropic cytokine exerting its role at different stages of bone marrow development and affecting eosinophil activation, mast cells and basophil chemotaxis and survival. The aim of the study was to assess concentration of SCF and its soluble receptor c-kit (sc-kit) in peripheral blood of patients with asthma referring it to asthma severity and phenotype.</p> <p>Methods</p> <p>The study involved 107 patients with bronchial asthma, well characterized with respect to severity and 21 healthy controls. Concentration of SCF and sc-kit in the patients serum were measured by ELISA method.</p> <p>Results</p> <p>Mean serum SCF level in the group of asthmatics (n = 88) was significantly higher as compared to healthy controls (1010 pg/ml ± 37 vs 799 ± 33; p < 0,001). The level of SCF was higher in patients with severe asthma as compared to patients with non-severe asthma (1054 +/- 41 pg/ml vs 819 +/- 50; p < 0,01) and correlated with dose of inhaled glucocorticosteroids taken by the patients to achieve asthma control (R = 0,28; p < 0,01). The mean sc-kit serum level did not differ between asthmatic patients and healthy controls, however the level of sc-kit in non-severe asthmatics was significantly higher as compared to patients with severe asthma and healthy controls. In asthmatic patients (n = 63) the level of sc-kit correlated positively with FEV1% predicted value (R = 0,45; p < 0,001) and MEF25% predicted value (R = 0,33; p < 0,01). The level of sc-kit inversely correlated with the dose of inhaled glucocorticosteroids taken by the patients (R = -0,26; p < 0,01).</p> <p>Conclusion</p> <p>Serum levels of SCF and its soluble receptor c-kit seem to be reflect asthma severity suggesting a role for these molecules in asthmatic inflammation.</p

Effect of early and current Helicobacter pylori infection on the risk of anaemia in 6.5-year-old Ethiopian children

Background: Epidemiological and clinical studies in high income countries have suggested that Helicobacter pylori (H. pylori) may cause anaemia, but evidence is lacking from low income countries.We examined associations between H. pylori infection in early childhood and anaemia at the age of 6.5 years in an Ethiopian birth cohort. Methods: In 2011/12, 856 children (85.1 % of the 1006 original singletons in a population-based birth cohort) were followed up at age six and half. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Haemoglobin level and red cell indices were examined using an automated haematological analyzer (Cell Dyn 1800, Abbott, USA), and stool samples analyzed for H. pylori antigen. The independent effects of H. pylori infection (measured at age 3.5 and 6.5 years) on anaemia, haemoglobin level, and red cell indices (measured at age 6.5 years) were determined using multiple logistic and linear regression. Results: The prevalence of anemia was 34.8 % (257/739), and the mean (SD) haemoglobin concentration was 11.8 (1.1) gm/dl. Current H. pylori infection at age 6.5 years was positively, though not significantly related to prevalence of anaemia (adjusted OR, 95 % CI, 1.15; 0.69, 1.93, p = 0.59). Any H. pylori infection up to age 6.5 years was significantly associated with an increased risk of anaemia at age 6.5 (adjusted OR, 95 % CI, 1.68; 1.22, 2.32, p = 0.01). A significant reduction in haemoglobin concentration and red cell indices was also observed among children who had any H. pylori infection up to age 6.5 (Hb adjusted β = −0.19, 95 % CI, −0.35 to −0.03, p = 0.01; MCV adjusted β = −2.22, 95 % CI, −3.43 to −1.01, p = 0.01; MCH adjusted β = −0.63, 95 % CI, −1.15 to - 0.12, p = 0.01; and MCHC adjusted β = −0.67, 95 % CI, −1.21 to −0.14, p = 0.01), respectively. Conclusion: This study provides further evidence from a low income country that any H. pylori infection up to age 6.5 is associated with higher prevalence of anaemia, and reduction of haemoglobin level and red cell indices at age 6.5