Neurogenic disturbances of cardiac rhythm

Arrhythmias are disturbances of electrical activation of the heart and are commonly encountered clinical conditions. Although typically associated with cardiac pathology, they have also been described in stroke and epilepsy. Two closely related structures, the insula and the temporal lobe, particularly the mesial region, have been implicated. Derangement of central autonomic control appears to be a key driver in neurogenic arrhythmogenesis and both these structures appear to play some role in influencing autonomic activity. Our understanding of this phenomenon is only in its infancy, and more research will be necessary to further it.peer-reviewe

Teaching first-generation newcomers in charter high schools: teachers’ perceptions of students’ barriers, teaching practices and strategies, and teaching supports

Teachers in the United States are experiencing challenges linked to the increasing number of immigrant students entering schools. Los Angeles County Charter schools are among the country\u27s most diverse, with many immigrant students. Although first-generation and immigrant students’ education barriers and teacher challenges are documented, little is known about teachers\u27 experiences with newcomer students, a particularly vulnerable group. This phenomenological study explored charter high school teachers’ lived experiences concerning their teaching challenges and perspectives on the barriers for first-generation/newcomer immigrant students, their descriptions of the strategies and practices used, and their perceptions of the support they receive. Twelve teachers from 3 high schools participated in one-on-one interviews with 10 questions. Virtual interviews were recorded, transcribed, and analyzed using coding and thematic analysis, emphasizing a phenomenological multiple perspectives approach. Bandura’s self-efficacy theory was used to interpret the findings for three research questions and the related literature. Three themes were developed: (a) meeting the learners where they are to understand their challenges and barriers to learning; (b) purposefully, responsibly, resiliently, and collaboratively building learning strategies and reflecting a multicultural school climate; (c) recognizing the benefits and needs to improve professional development: the champions and the discontented. Three conclusions were found: (a) teachers need more training on overcoming barriers and challenges to teaching first-generation students, (b) teachers need support in using teaching strategies and engaging first-generation students, and (c) teachers need more time for collaboration. Recommendations for teachers included (a) finding ways to build their resiliency and self-efficacy, (b) taking responsibility for their classrooms and creating a positive environment, (c) showing empathy toward newcomers, (d) embracing multicultural learning, (e) collaborating, and (f) using multiple and multimodal learning strategies. Among the several recommendations for administrators and site leaders were (a) communicating with the families, (b) creating teacher professional development, (c) dedicating time for collaboration, and (d) sharing a clear vision for a multicultural climate and educational environment. The recommendations for policy and practice were (a) to have teachers discuss concerns for first- generation immigrant students, (b) to provide dedicated time to address newcomers\u27 needs, and (c) to provide strategies and support for teaching newcomer students

Time-Restricted Feeding Improves Circadian Dysfunction as well as Motor Symptoms in the Q175 Mouse Model of Huntington's Disease.

Huntington's disease (HD) patients suffer from a progressive neurodegeneration that results in cognitive, psychiatric, cardiovascular, and motor dysfunction. Disturbances in sleep/wake cycles are common among HD patients with reports of delayed sleep onset, frequent bedtime awakenings, and fatigue during the day. The heterozygous Q175 mouse model of HD has been shown to phenocopy many HD core symptoms including circadian dysfunctions. Because circadian dysfunction manifests early in the disease in both patients and mouse models, we sought to determine if early intervention that improve circadian rhythmicity can benefit HD and delay disease progression. We determined the effects of time-restricted feeding (TRF) on the Q175 mouse model. At six months of age, the animals were divided into two groups: ad libitum (ad lib) and TRF. The TRF-treated Q175 mice were exposed to a 6-h feeding/18-h fasting regimen that was designed to be aligned with the middle of the time when mice are normally active. After three months of treatment (when mice reached the early disease stage), the TRF-treated Q175 mice showed improvements in their locomotor activity rhythm and sleep awakening time. Furthermore, we found improved heart rate variability (HRV), suggesting that their autonomic nervous system dysfunction was improved. Importantly, treated Q175 mice exhibited improved motor performance compared to untreated Q175 controls, and the motor improvements were correlated with improved circadian output. Finally, we found that the expression of several HD-relevant markers was restored to WT levels in the striatum of the treated mice using NanoString gene expression assays

A microrod-resonator Brillouin laser with 240 Hz absolute linewidth

We demonstrate an ultralow-noise microrod-resonator based laser that oscillates on the gain supplied by the stimulated Brillouin scattering optical nonlinearity. Microresonator Brillouin lasers are known to offer an outstanding frequency noise floor, which is limited by fundamental thermal fluctuations. Here, we show experimental evidence that thermal effects also dominate the close-to-carrier frequency fluctuations. The 6-mm diameter microrod resonator used in our experiments has a large optical mode area of ~100 {\mu}m$^2$, and hence its 10 ms thermal time constant filters the close-to-carrier optical frequency noise. The result is an absolute laser linewidth of 240 Hz with a corresponding white-frequency noise floor of 0.1 Hz$^2$/Hz. We explain the steady-state performance of this laser by measurements of its operation state and of its mode detuning and lineshape. Our results highlight a mechanism for noise that is common to many microresonator devices due to the inherent coupling between intracavity power and mode frequency. We demonstrate the ability to reduce this noise through a feedback loop that stabilizes the intracavity power.Comment: 11 pages, 5 figure

Best Sourcing - Towards Lean ICT Shared Services In A Singapore Government Organisation

Many government organisations in Singapore have been embarking on a strategic decision to drive lean public service by pushing down costs for operating expenditures, improving service performance and concentrating all or most of the resources available on core business. In such circumstances, outsourcing becomes almost inevitable. Outsourcing allows the organisation to focus on its core business by transferring operational functions to external specialists. Public Provident Service (PPS), a public social security organisation, faces the same dilemma of escalating IT costs and reduction in service performance due to increasingly being required to coordinate the delivery of duplicated services across business units. The evolution began one year ago when PPS made the bold, sweeping decision to have an external, market-tested Information and Communication Technology (ICT) organisation to execute standardised operating ICT operations. Some may call this outsourcing, but PPS's new approach to sourcing strategy was to build a partnership between best sourcing and shared services. This dissertation was to study the impact of ICT outsourcing in PPS. This research starts with a detailed literature review that highlights the pros and cons for different sourcing strategies and outlines the key findings of other authors. In the analysis chapter, different aspects of business, economic, shared-services and technical on sourcing strategies are examined that helped PPS to devise the best sourcing on shared ICT services strategy plan. The subsequent analysis would address the key business areas in which the organisation needs to achieve significant improvement if it has to meet its strategic objectives. Furthermore, it addressed the consequences on the business operations and changes, risks and challenges to overcome finally the implementation of the best sourcing on ICT shared services. At the end, the main conclusions from this study is that the best sourcing on shared ICT services strategy plan drives PPS towards lean and efficient public services. With a standard ICT operating environment implemented in PPS to derive significant cost savings while enhancing operating efficiency and providing higher quality service performance

Virtual sensing directional hub MAC (VSDH-MAC) protocol with power control

Medium access control (MAC) protocols play a vital role in making effective use of a multiple access channel as it governs the achievable performance such as channel utilization and corresponding quality of service of wireless sensor networks (WSNs). In this paper, a virtual carrier sensing directional hub (VSDH) MAC protocol incorporating realistic directional antenna patterns is proposed for directional single hub centralized WSNs. While in most instances, MAC protocols assume idealized directional antenna patterns, the proposed VSDH-MAC protocol incorporates realistic directional antenna patterns to deliver enhanced link performance. We demonstrate that the use of directional antennas with a suitable MAC protocol can provide enhanced communication range and increased throughput with reduced energy consumption at each node, compared to the case when only omnidirectional antennas are used. For the scenarios considered in this study, results show that the average transmit power of the sensor nodes can be reduced by a factor of two, and at the same time offer significantly extended lifetime

Best Sourcing - Towards Lean ICT Shared Services In A Singapore Government Organisation

Many government organisations in Singapore have been embarking on a strategic decision to drive lean public service by pushing down costs for operating expenditures, improving service performance and concentrating all or most of the resources available on core business. In such circumstances, outsourcing becomes almost inevitable. Outsourcing allows the organisation to focus on its core business by transferring operational functions to external specialists. Public Provident Service (PPS), a public social security organisation, faces the same dilemma of escalating IT costs and reduction in service performance due to increasingly being required to coordinate the delivery of duplicated services across business units. The evolution began one year ago when PPS made the bold, sweeping decision to have an external, market-tested Information and Communication Technology (ICT) organisation to execute standardised operating ICT operations. Some may call this outsourcing, but PPS's new approach to sourcing strategy was to build a partnership between best sourcing and shared services. This dissertation was to study the impact of ICT outsourcing in PPS. This research starts with a detailed literature review that highlights the pros and cons for different sourcing strategies and outlines the key findings of other authors. In the analysis chapter, different aspects of business, economic, shared-services and technical on sourcing strategies are examined that helped PPS to devise the best sourcing on shared ICT services strategy plan. The subsequent analysis would address the key business areas in which the organisation needs to achieve significant improvement if it has to meet its strategic objectives. Furthermore, it addressed the consequences on the business operations and changes, risks and challenges to overcome finally the implementation of the best sourcing on ICT shared services. At the end, the main conclusions from this study is that the best sourcing on shared ICT services strategy plan drives PPS towards lean and efficient public services. With a standard ICT operating environment implemented in PPS to derive significant cost savings while enhancing operating efficiency and providing higher quality service performance