Circular polarization switching and bistability in an optically injected 1300 nm spin-vertical cavity surface emitting laser

We report the experimental observation of circular polarization switching (PS) and polarization bistability (PB) in a 1300 nm dilute nitride spin-vertical cavity surface emitting laser (VCSEL). We demonstrate that the circularly polarized optical signal at 1300 nm can gradually or abruptly switch the polarization ellipticity of the spin-VCSEL from right-to-left circular polarization and vice versa. Moreover, different forms of PS and PB between right- and left-circular polarizations are observed by controlling the injection strength and the initial wavelength detuning. These results obtained at the telecom wavelength of 1300 nm open the door for novel uses of spin-VCSELs in polarization sensitive applications in future optical systems

Power Consumption and Energy Estimation in Smartphones

A developer needs to evaluate software performance metrics such as power consumption at an early stage of design phase to make a device or a software efficient especially in real-time embedded systems. Constructing performance models and evaluation techniques of a given system requires a significant effort. This paper presents a framework to bridge between a Functional Modeling Approach such as FSM, UML etc. and an Analytical (Mathematical) Modeling Approach such as Hierarchical Performance Modeling (HPM) as a technique to find the expected average power consumption for different layers of abstractions. A Hierarchical Generic FSM “HGFSM” is developed to be used in order to estimate the expected average power. A case study is presented to illustrate the concepts of how the framework is used to estimate the average power and energy produced

Study Protocol for "MOVEdiabetes":A Trial to Promote Physical Activity for Adults with Type 2 Diabetes in Primary Health Care in Oman

Abstract Background Benefits of physical activity in the management of diabetes are well documented. However, evidence on the effectiveness of interventions integrating physical activity in diabetes care is sparse especially in the countries of the Gulf Cooperation Council. The results from this study will increase our understanding of the use of multi-component interventions aimed at increasing physical activity levels in inactive adults with type 2 diabetes in primary health care in Oman. Methods/design The study is a one year 1:1 cluster randomized controlled trial of the MOVEdiabetes programme (intervention) versus usual care in eight primary health care centres in Oman. The MOVEdiabetes programme utilizes face to face physical activity consultations promoting 150 min of moderate to vigorous physical activity per week (≥600MET-mins/week), pedometers to self-monitor step counts and monthly telephone WhatsApp messages for follow up support. Inactive adults with type 2 diabetes and no contraindication to physical activity will be recruited over a two months period, and followed up for 12 months. To demonstrate a 50% between group difference in physical activity levels (MET-mins/week) over 12 months, (at a power of 80%, and significance level of 5%), 128 participants would be required to complete the study (64 in each arm). Based on a drop-out rate of 20%, 154 participants would require to be recruited (77 in each arm). Assuming a recruitment rate of 70%, 220 potential eligible participants would need to be approached. The primary outcome is change in levels of physical activity measured by the Global Physical Activity Questionnaire. In addition, accelerometers will be used in a sub group to objectively assess physical activity. Secondary outcomes include changes in metabolic and cardiovascular biomarkers, change in self-reported health, social support, self-efficacy for physical activity, and perceived acceptability of the program. All intervention delivery and support costs will be monitored. Discussion This study will contribute to the evidence on the feasibility, cultural acceptability and efficacy of interventional approaches for increasing physical activity in primary care for persons with type 2 diabetes in Oman. Trial registration International Standard Randomised Controlled Trials No: ISRCTN14425284 . Registered 12 April 2016

Differences in the Activity of Endogenous Bone Morphogenetic Protein Signaling Impact on the Ability of Induced Pluripotent Stem Cells to Differentiate to Corneal Epithelial-Like Cells

Cornea is a clear outermost layer of the eye which enables transmission of light onto the retina. The transparent corneal epithelium is regenerated by limbal stem cells (LSCs), whose loss/dysfunction results in LSCs deficiency (LSCD). Ex vivo expansion of autologous LSCs obtained from patient's healthy eye followed by transplantation onto the LSCs damaged/deficient eye, has provided a successful treatment for unilateral LSCD. However, this is not applicable to patient with total bilateral LSCD, where LSCs are lost/damaged from both eyes. We investigated the potential of human induced pluripotent stem cell (hiPSC) to differentiate into corneal epithelial-like cells as a source of autologous stem cell treatment for patients with total bilateral LSCD. Our study showed that combined addition of bone morphogenetic protein 4 (BMP4), all trans-retinoic acid and epidermal growth factor for the first 9 days of differentiation followed by cell-replating on collagen-IV-coated surfaces with a corneal-specific-epithelial cell media for an additional 11 days, resulted in step wise differentiation of human embryonic stem cells (hESC) to corneal epithelial progenitors and mature corneal epithelial-like cells. We observed differences in the ability of hiPSC lines to undergo differentiation to corneal epithelial-like cells which were dependent on the level of endogenous BMP signaling and could be restored via the activation of this signaling pathway by a specific transforming growth factor β inhibitor (SB431542). Together our data reveal a differential ability of hiPSC lines to generate corneal epithelial cells which is underlined by the activity of endogenous BMP signaling pathway

Control of emitted light polarization in a 1310 nm dilute nitride spin-vertical cavity surface emitting laser subject to circularly polarized optical injection

We experimentally demonstrate the control of the light polarization emitted by a 1310 nm dilute nitride spin-Vertical Cavity Surface Emitting Laser (VCSEL) at room temperature. This is achieved by means of a combination of polarized optical pumping and polarized optical injection. Without external injection, the polarization of the optical pump controls that of the spin-VCSEL. However, the addition of the externally injected signal polarized with either left- (LCP) or rightcircular polarization (RCP) is able to control the polarization of the spin-VCSEL switching it at will to left- or right-circular polarization. A numerical model has been developed showing a very high degree of agreement with the experimental findings

Standards of Islamic Rooting for the Concepts of Education

The study aimed to identify a set of Islamic standards for the educational concepts that should be taken into account when addressing the process of Islamic rooting. The researcher used the analytical descriptive method, and the results of the study showed the absence of Interdisciplinary studies, which may contribute more to correcting the methodology of Islamic rooting for educational sciences, among specialists in the origins of education and other disciplines in the educational fields or otherwise. Thus, the study presented a set of Islamic Rooting standards for the educational concepts which are: reliance on sources of Islamic education, adherence to the rules of derivation and reasoning in Islamic methodology, ability to critique and deal with the heritage tales and understanding and knowledge of Arabic language methods and their multiple uses. The distinction between the sources of knowledge in Islam and other nations, starting from the Islamic perception of the universe, man and life, extensive knowledge in the field of education and work within the field. Results also indicate the presentation of educational concepts clearly after rooting them, verification of rooting objectives of educational concepts, emergence of features of the methodology of Islamic roots when dealing with educational concepts, averageness in dealing with educational concepts coming from other educational cultures, taking into consideration the aspects of the legal dispute and its reflection on educational applications. The study concluded with a set of recommendations in the light of its finding

An Analysis of the Binding Characteristics of a Panel of Recently Selected ICAM-1 Binding Plasmodium falciparum Patient Isolates.

The basis of severe malaria pathogenesis in part includes sequestration of Plasmodium falciparum-infected erythrocytes (IE) from the peripheral circulation. This phenomenon is mediated by the interaction between several endothelial receptors and one of the main parasite-derived variant antigens (PfEMP1) expressed on the surface of the infected erythrocyte membrane. One of the commonly used host receptors is ICAM-1, and it has been suggested that ICAM-1 has a role in cerebral malaria pathology, although the evidence to support this is not conclusive. The current study examined the cytoadherence patterns of lab-adapted patient isolates after selecting on ICAM-1. We investigated the binding phenotypes using variant ICAM-1 proteins including ICAM-1Ref, ICAM-1Kilifi, ICAM-1S22/A, ICAM-1L42/A and ICAM-1L44/A using static assays. The study also examined ICAM-1 blocking by four anti-ICAM-1 monoclonal antibodies (mAb) under static conditions. We also characterised the binding phenotypes using Human Dermal Microvascular Endothelial Cells (HDMEC) under flow conditions. The results show that different isolates have variant-specific binding phenotypes under both static and flow conditions, extending our previous observations that this variation might be due to variable contact residues on ICAM-1 being used by different parasite PfEMP1 variants

Health professionals’ perceptions about physical activity promotion in diabetes care within primary health care settings in Oman

Background: As part of formative work to inform an interventional design to increase physical activity (PA) in patients with type 2 diabetes in Oman, this qualitative study aimed to determine health professionals’ perception of barriers and opportunities, personnel responsibilities and plausible PA promotional approaches. Methods: Four focus group discussions were carried out with groups of health care professionals (family physicians, dieticians and health educators, managers and general practitioners). All discussions were audio recorded and transcribed. Responses were analysed using a thematic analysis. Results: Barriers to PA reported by participants (n = 29) were identified at three levels: health care system (e.g. deficient PA guidelines); individual (e.g. obstructive social norms) and community (e.g. lack of facilities). Participants felt that a multilevel approach is needed to address perceived barriers and to widen current opportunities. In the presence of various diabetes primary care providers, the potential for dieticians to include individualised PA consultations as part of their role was highlighted. Participants felt that consultations should be augmented by approaches within the community (volunteer support and/or appropriate facilities). However, despite lack of experience with technology supported approaches and motivational tools, the telephone application “WhatsApp” and use of pedometers were considered potentially suitable. The need for training in behaviour change techniques and clearly communicated intervention guidelines was emphasised. Conclusions: A multi-component approach including PA consultations, possibly led by trained dieticians, technological routes for providing support along with community mapping for resources appear to offer promising approaches for further PA intervention studies within diabetes primary health care