Experimental investigation of the impact of optical injection on vital parameters of a gain-switched pulse source

An analysis of optical injection on a gain-switched distributed feedback (DFB) laser and its impact on pulse parameters that influence the performance of the pulse source in high-speed optical communication systems is presented in this paper. A range of 10 GHz in detuning and 5 dB in injected power has been experimentally identified to attain pulses, from an optically injected gain-switched DFB laser, with durations below 10 ps and pedestal suppression higher than 35 dB. These pulse features are associated with a side mode suppression ratio of about 30 dB and a timing jitter of less than 1 ps. This demonstrates the feasibility of using optical injection in conjunction with appropriate pulse compression schemes for developing an optimized and cost-efficient pulse source, based on a gain-switched DFB laser, for high-speed photonic systems

Discrete mode laser diodes with ultra narrow linewidth emission <3kHz

Ex-facet, free-running ultra-low linewidth (<3 kHz), single mode laser emission is demonstrated using low cost, regrowth-free ridge waveguide discrete mode Fabry-Perot laser diode chips

Successes, challenges and needs regarding rural health medical education in continental central America: A literature review and narrative synthesis

Introduction: Central American countries, like many others, face a shortage of rural health physicians. Most medical schools in this region are located in urban areas and focus on tertiary care training rather than on community health or primary care, which are better suited for rural practice. However, many countries require young physicians to do community service in rural communities to address healthcare provider shortages. This study aimed to: (a) synthesize what is known about the current state of medical education preparing physicians for rural practice in this region, and (b) identify common needs, challenges and opportunities for improving medical education in this area. Methods: A comprehensive literature review was conducted between December 2013 and May 2014. The stepwise, reproducible search process included English and Spanish language resources from both data-based web search engines (PubMed, Web of Science/Web of Knowledge, ERIC and Google Scholar) and the grey literature. Search criteria included MeSH terms: ‘medical education’, ‘rural health’, ‘primary care’, ‘community medicine’, ‘social service’, in conjunction with ‘Central America’, ‘Latin America’, ‘Mexico’, ‘Guatemala’, ‘Belize’, ‘El Salvador’, ‘Nicaragua’, ‘Honduras’, ‘Costa Rica’ and ‘Panama’. Articles were included in the review if they (1) were published after 1984; (2) focused on medical education for rural health, primary care, community health; and (3) involved the countries of interest. A narrative synthesis of the content of resources meeting inclusion criteria was done using qualitative research methods to identify common themes pertaining to the study goals. Results: The search revealed 20 resources that met inclusion criteria. Only four of the 20 were research articles; therefore, information about this subject was primarily derived from expert opinion. Thematic analysis revealed the historical existence of several innovative programs that directly address rural medicine training needs, suggesting that expertise is present in this region. However, numerous challenges limit sustainability or expansion of successful programs. Common challenges include: (a) physicians’ exposure to rural medicine primarily takes place during social service commitment time, rather than during formal medical training; (b) innovative educational programs are often not sustainable due to financial and leadership challenges; (c) the majority of physician manpower is in urban areas, resulting in few rural physician role models and teachers; and (d) there is insufficient collaboration to establish clinical and educational systems to meet rural health needs. Recurring suggestions for curricular changes include: (a) making primary care training a core component of medical school education; and (b) expanding medical school curricula in crosscultural communication and social determinants of disease. Suggestions for health system changes include: (a) improving living and working conditions for rural physicians; and (b) establishing partnerships between educational, governmental and non-governmental organizations and rural community leadership, to promote rural health training and systems. Conclusions: Expertise in rural medicine and training exists in continental Central America. However, there are numerous challenges to improving medical education to meet the needs of rural communities. Overcoming these challenges will require creative solutions, new partnerships, and evaluation and dissemination of successful educational programs. There is a great need for further research on this topic

Increased bit rate direct modulation AMO-OFDM transmission by optical injection using monolithically integrated lasers

Experimental and simulation work, presented in this letter, demonstrates for the first time how the monolithic integration of two single-mode lasers in a master-slave configuration, can substantially increase the achievable bit rate of a direct modulation adaptively modulated optical orthogonal frequency-division multiplexing (AMO-OFDM) system. The Levin-Campello algorithm is applied to select the OFDM bit and power loading scheme used for each system configuration. Improvement in terms of data throughput due to injection is measured for several transmission distances with the improvement in performance presented in terms of error vector magnitude per OFDM subcarrier

Discrete mode laser diodes with very narrow linewidth emission

Ex-facet, free-running low linewidth (~100 kHz), single mode laser emission is demonstrated using low cost, regrowth-free ridge waveguide Discrete Mode Fabry Pérot laser diode chips. These narrow linewidths are obtained from sub mW emission powers and above

Reshaping maternal services in Nigeria: any need for spiritual care?

BACKGROUND:High maternal and perinatal mortalities occur from deliveries conducted in prayer houses in Nigeria. Although some regulatory efforts have been deployed to tackle this problem, less attention has been placed on the possible motivation for seeking prayer house intervention which could be hinged on the spiritual belief of patients about pregnancy and childbirth. This study therefore seeks to determine the perception of booked antenatal patients on spiritual care during pregnancy and their desire for such within hospital setting.METHOD:A total of 397 antenatal attendees from two tertiary health institutions in southwest Nigeria were sampled. A pretested questionnaire was used to obtain information on socio-demographic features of respondents, perception of spiritual care during pregnancy and childbirth; and how they desire that their spiritual needs are addressed. Responses were subsequently collated and analyzed.RESULTS:Most of the women, 301 (75.8%), believe there is a need for spiritual help during pregnancy and childbirth. About half (48.5%) were currently seeking for help in prayer/mission houses while another 8.6% still intended to. Overwhelmingly, 281 (70.8%) felt it was needful for health professionals to consider their spiritual needs. Most respondents, 257 (64.7%), desired that their clergy is allowed to pray with them while in labour and sees such collaboration as incentive that will improve hospital patronage. There was association between high family income and desire for collaboration of healthcare providers with one's clergy (OR 1.82; CI 1.03-3.21; p?=?0.04).CONCLUSION:Our women desire spiritual care during pregnancy and childbirth. Its incorporation into maternal health services will improve hospital delivery rates

Mapping synergies and trade-offs between energy and the Sustainable Development Goals

The 2030 Agenda for Sustainable Development—including 17 interconnected Sustainable Development Goals (SDGs) and 169 targets—is a global plan of action for people, planet and prosperity. SDG7 calls for action to ensure access to affordable, reliable, sustainable and modern energy for all. Here we characterize synergies and trade-offs between efforts to achieve SDG7 and delivery of the 2030 Agenda as a whole. We identify 113 targets requiring actions to change energy systems, and published evidence of relationships between 143 targets (143 synergies, 65 trade-offs) and efforts to achieve SDG7. Synergies and trade-offs exist in three key domains, where decisions about SDG7 affect humanity’s ability to: realize aspirations of greater welfare and well-being; build physical and social infrastructures for sustainable development; and achieve sustainable management of the natural environment. There is an urgent need to better organize, connect and extend this evidence, to help all actors work together to achieve sustainable development. On 5 September 2015, the 193 members states of the United Nations (UN) adopted a new 2030 Agenda for Sustainable Development. The 2030 Agenda succeeds the UN’s Millennium Development Goals (MDGs), and features 17 Sustainable Development Goals (SDGs) with 169 targets, which UN member states have committed to implement by 2030. Energy was not explicitly referred to in the MDGs, and came to be referred to as the ‘missing’ MDG. During the operational period of the MDGs and negotiation of the 2030 Agenda, it was increasingly recognized that energy underpins economic and social development, without which it would not be possible to eliminate poverty. This change in status made sustainable energy provision and access one of the central themes of the 2030 Agenda, whose preamble calls for “universal access to affordable, reliable and sustainable energy” and recognizes that “social and economic development depends of the sustainable management of our planet’s natural resources”. SDG7 is accompanied by five targets to be achieved by 2030: ensure universal access to affordable, reliable and modern energy services (7.1); increase the share of renewable energy in the global energy mix (7.2); double the global rate of improvement in energy efficiency (7.3); enhance international cooperation to facilitate access to clean energy research and technology (7.a), and promote investment in energy infrastructure and clean energy technology (7.b). By understanding the complex links between the SDGs and their constituent targets, researchers can better support policymakers to think systematically about interactions between the different SDGs, including how actions to achieve each goal affect each other within and between sectors. Studies to date have lacked a target-level approach or have focussed on only a few of the SDGs. Here we present a formative attempt by an interdisciplinary group of researchers to identify the full range of goals and targets in the 2030 Agenda that call for changes in energy systems, and characterize evidence of synergies or trade-offs between delivery of each of the 169 targets and efforts focussed on pursuit of SDG7 and each of its constituent targets. The purpose of this Perspective is not to provide definitive answers. Instead we aim to lay a foundation for systematic (and context-specific) exploration of the interlinkages between each of the SDG targets, in the context of decision-making about development and the transformation of energy systems