The proliferation of distributed energy resources is setting the stage for modern distribution systems to operate as microgrids, which can avoid power disruptions and serve as resources for fast recovery during macrogrid disturbances. Microgrids are, therefore, major assets to improve the grid resilience. However, the offered resilience is seriously undermined if microgrids are not properly protected in the event of faults within their own boundaries. Distribution protective devices cannot reliably protect microgrids due to the variable and often limited short-circuit capacities of microgrids. Moreover, the research on microgrid protection has not led to a commercially available microgrid relay to date and has little prospect of reaching that level in the near future. As a result, the existing options for reliable microgrid protection remain effectively the subtransmission and transmission system protective devices, e.g., directional overcurrent, distance, and differential relays. Although years of operation in macrogrids support these relays, their performance for microgrids is yet to be analyzed. This paper presents such analysis for different relay types by considering various fault and generation conditions in a microgrid. Time-domain simulations are used to identify the scenarios where the relays function correctly as well as the problematic conditions, on which future research should focus. This paper also presents a short review on direct current (dc) microgrids and their protection requirements.
This paper describes a six-year large scale implementation of the Signs of Safety practise framework in a complex statutory child protection context in Western Australia. The case study documents both the practitioner-led and organisational-led implementation journey as part of the State's child protection system reform drawing on Roger's diffusion of innovation theory and Fixsen's five stage implementation model as conceptual frameworks, and highlighting the key facilitators and barriers. The study is a collaboration between researchers investigating the impact and use of Signs of Safety in Western Australia who contributed the theoretical perspectives and analysis; and key personnel from the Department responsible for implementation who contributed documents, manuals, records and personal accounts to form the narrative of the implementation. A naturalist, intrinsic and multiple case study design utilising semi-structured interviews was used to consult with 27 Departmental staff and practitioners. Thematic analysis was utilised to identify key themes and patterns of experiences with the Signs of Safety framework implementation. Much can be learned from the journey of the Department and their long term commitment and systematic implementation strategy of Signs of Safety including the significance of leadership, learning and developing initiatives, effective communication, instituting continuous improvement processes and the provision of feedback for individual practitioners. Signs of Safety appealed to natural champions of systemic social work practise within the Department whose organisational culture adapted to align with the principles of the framework in building partnerships and understanding with families, being solution-focused, maintaining an open stance of inquiry and balancing strengths and safety around children whilst concurrently working to solve dangers and harm. As a learning organisation, the Department also utilised case practise implementation teams to be able to move through more successfully the different stages of implementation. In utilising Fixsen's implementation framework, the challenges and gaps to implementation strategies were also highlighted, including a problematic data system and an internal focus compromising the success of interagency collaboration. This discussion paper has provided an overview of the key concepts of the diffusion and implementation literature, and highlighted the importance of utilising theoretical frameworks in guiding implementation of practise models especially in complex statutory child protection contexts. Findings will be of particular interest to child welfare leaders and supporters of organisational change, providing concrete examples of implementation strategies and demonstrates the systemic benefits of a theoretical framework for guiding implementation efforts. •Importance of utilising theoretical frameworks for guiding implementation and change efforts•Significance of leadership, learning initiatives and provision of feedback for individual practitioners as key facilitators•Alignment of Signs of Safety® framework and Departmental organisational culture in building partnerships with families•Problematic data systems and interagency collaboration were identified as key challenges.
As a kind of medical service around people, community health care is closely related to peoples lives, and thus it has also been placed higher requirements. In the face of growing community medical needs, the construction and development of community medical Internet of things is imminent. Subsequently, massive multi-type of medical data which contain all kinds of user identity data, various types of vital signs data and other sensitive information are generated. Such a large scale of data in the transmission, storage and access process is facing the risk of data leakage. To effectively protect the privacy information of patients, an infrastructure framework for privacy protection of community medical Internet of things is proposed. It includes transmission protection based on multi-path asymmetric encryption fragment transmission mechanism, storage protection using distributed symmetric encryption cloud storage scheme and access control with identity authentication and dynamic access authorization. Through theoretical analysis and simulation experiments, it is proved that the community medical data can be effectively protected.
Carbohydrates, which are ubiquitously distributed throughout the three domains of life, play significant roles in a variety of vital biological processes. Access to unique and homogeneous carbohydrate materials is important to understand their physical properties, biological functions, and disease-related features. It is difficult to isolate carbohydrates in acceptable purity and amounts from natural sources. Therefore, complex saccharides with well-defined structures are often most conviently accessed through chemical syntheses. Two major hurdles, regioselective protection and stereoselective glycosylation, are faced by carbohydrate chemists in synthesizing these highly complicated molecules. Over the past few years, there has been a radical change in tackling these problems and speeding up the synthesis of oligosaccharides. This is largely due to the development of one–pot protection, one–pot glycosylation, and one–pot protection–glycosylation protocols and streamlined approaches to orthogonally protected building blocks, including those from rare sugars, that can be used in glycan coupling. In addition, new automated strategies for oligosaccharide syntheses have been reported not only for program-controlled assembly on solid support but also by the stepwise glycosylation in solution phase. As a result, various sugar molecules with highly complex, large structures could be successfully synthesized. To summarize these recent advances, this review describes the methodologies for one-pot protection and their one-pot glycosylation into the complex glycans and the chronological developments associated with automated syntheses of oligosaccharides.
Highlights • Polyphosphate protects bacteria from oxidative stress by multiple mechanisms. • Polyphosphate is a chaperone that prevents aggregation of oxidized proteins. • Polyphosphate–metal complexes lower levels of ROS and redox-active metals in cells. • Polyphosphate is a key regulator of persister cell formation. • Polyphosphate is involved in regulation of general stress response networks.
Background: Photodamage is partially mitigated by darker skin pigmentation, but immune suppression, photoaging and cataracts occur among individuals with all skin types. Methods: To assess practices and acceptability to Black African mothers of sun protection equipment for their children living in a rural area, participants were recruited at the time of their child's 18-month vaccinations. Mothers completed a baseline questionnaire on usual sun behaviours and sun protection practices. They were then provided with sun protection equipment and advice. A follow-up questionnaire was administered two weeks later. Results: Mothers reported that during the week prior to the baseline questionnaire, children spent on average less than 1 hour of time outdoors (most often spent in the shade). Most mothers (97%) liked the sun protection equipment. However, many (78 of 86) reported that their child did not like any of the sun protection equipment and two-thirds stated that the sun protection equipment was not easy to use. Conclusions: Among Black Africans in rural northern South Africa, we found a mismatch between parental preferences and child acceptance for using sun protection when outdoors. A better understanding of the health risks of incidental excess sun exposure and potential benefits of sun protection is required among Black Africans.
This report provides a review of early and late effects of radiation in normal tissues and organs with respect to radiation protection. It was instigated following a recommendation in Publication 103 (ICRP, 2007), and it provides updated estimates of ‘practical’ threshold doses for tissue injury defined at the level of 1% incidence. Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated, or chronic exposure. The organ systems comprise the haematopoietic, immune, reproductive, circulatory, respiratory, musculoskeletal, endocrine, and nervous systems; the digestive and urinary tracts; the skin; and the eye. Particular attention is paid to circulatory disease and cataracts because of recent evidence of higher incidences of injury than expected after lower doses; hence, threshold doses appear to be lower than previously considered. This is largely because of the increasing incidences with increasing times after exposure. In the context of protection, it is the threshold doses for very long follow-up times that are the most relevant for workers and the public; for example, the atomic bomb survivors with 40–50years of follow-up. Radiotherapy data generally apply for shorter follow-up times because of competing causes of death in cancer patients, and hence the risks of radiation-induced circulatory disease at those earlier times are lower. A variety of biological response modifiers have been used to help reduce late reactions in many tissues. These include antioxidants, radical scavengers, inhibitors of apoptosis, anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, growth factors, and cytokines. In many cases, these give dose modification factors of 1.1–1.2, and in a few cases 1.5–2, indicating the potential for increasing threshold doses in known exposure cases. In contrast, there are agents that enhance radiation responses, notably other cytotoxic agents such as antimetabolites, alkylating agents, anti-angiogenic drugs, and antibiotics, as well as genetic and comorbidity factors. Most tissues show a sparing effect of dose fractionation, so that total doses for a given endpoint are higher if the dose is fractionated rather than when given as a single dose. However, for reactions manifesting very late after low total doses, particularly for cataracts and circulatory disease, it appears that the rate of dose delivery does not modify the low incidence. This implies that the injury in these cases and at these low dose levels is caused by single-hit irreparable-type events. For these two tissues, a threshold dose of 0.5Gy is proposed herein for practical purposes, irrespective of the rate of dose delivery, and future studies may elucidate this judgement further.
Lutein and zeaxanthin (L/Z) are the predominant carotenoids which accumulate in the retina of the eye. The impact of L/Z intake on the risk and progression of age-related macular degeneration (AMD), a leading cause of blindness in the developed world, has been investigated in cohort studies and clinical trials. The aims of this review were to critically examine the literature and evaluate the current evidence relating to L/Z intake and AMD, and describe important food sources and factors that increase the bioavailability of L/Z, to inform dietary models. Cohort studies generally assessed L/Z from dietary sources, while clinical trials focused on providing L/Z as a supplement. Important considerations to take into account in relation to dietary L/Z include: nutrient-rich sources of L/Z, cooking methods, diet variety and the use of healthy fats. Dietary models include examples of how suggested effective levels of L/Z can be achieved through diet alone, with values of 5 mg and 10 mg per day described. These diet models depict a variety of food sources, not only from dark green leafy vegetables, but also include pistachio nuts and other highly bioavailable sources of L/Z such as eggs. This review and the diet models outlined provide information about the importance of diet variety among people at high risk of AMD or with early signs and symptoms of AMD.
The current study sought to expand upon research on motivated empathic (in)accuracy by testing assumptions underlying the empathic accuracy model, namely if a perceiver's level of empathic accuracy is variable and might be associated with different outcomes depending the situation. More specifically, the model assumes that (a) the perception of threat in the thoughts/feelings of an interaction partner can result in a lower level of empathic accuracy, and (b) empathic accuracy can both improve and harm situational well-being on the personal and relationship level. These assumptions were tested in a laboratory-based study in which couples participated in a conflict interaction task and reported on their thought processes during a video-review task. All participants also completed a similar standard-stimulus task. A shift in participants' motivation to be accurate to a motivation to be inaccurate in response to perceived threat could not be detected. Men's higher levels of empathic accuracy for non-threatening feelings of their female partner were predictive of an increased feeling of closeness in men. Women's higher levels of empathic accuracy for non-threatening feelings of the male partner were predictive for a better mood in women. A harmful effect of empathic accuracy for threatening thoughts/feelings on situational well-being was not found.
In plants, small RNA (sRNA)-mediated RNA interference (RNAi) is critical for regulating host immunity against bacteria, fungi, oomycetes, viruses, and pests. Similarly, sRNAs from pathogens and pests also play an important role in modulating their virulence. Strikingly, recent evidence supports that some sRNAs can travel between interacting organisms and induce gene silencing in the counter party, a mechanism termed cross-kingdom RNAi. Exploiting this new knowledge, host-induced gene silencing (HIGS) by transgenic expression of pathogen gene-targeting double-stranded (ds)RNA has the potential to become an important disease-control method. To circumvent transgenic approaches, direct application of dsRNAs or sRNAs (environmental RNAi) onto host plants or post-harvest products leads to silencing of the target microbe/pest gene (referred to spray-induced gene silencing, SIGS) and confers efficient disease control. This review summarizes the current understanding of cross-kingdom RNA trafficking and environmental RNAi and how these findings can be developed into novel effective strategies to fight diseases caused by microbial pathogens and pests.