Optimum coding techniques for MST radars

The optimum coding technique for MST (mesosphere stratosphere troposphere) radars is that which gives the lowest possible sidelobes in practice and can be implemented without too much computing power. Coding techniques are described in Farley (1985). A technique mentioned briefly there but not fully developed and not in general use is discussed here. This is decoding by means of a filter which is not matched to the transmitted waveform, in order to reduce sidelobes below the level obtained with a matched filter. This is the first part of the technique discussed here; the second part consists of measuring the transmitted waveform and using it as the basis for the decoding filter, thus reducing errors due to imperfections in the transmitter. There are two limitations to this technique. The first is a small loss in signal to noise ratio (SNR), which usually is not significant. The second problem is related to incomplete information received at the lowest ranges. An appendix shows a technique for handling this problem. Finally, it is shown that the use of complementary codes on transmission and nonmatched decoding gives the lowest possible sidelobe level and the minimum loss in SNR due to mismatch

Decoding: Codes and hardware implementation

The MST radars vary considerably from one installation to the next in the type of hardware, operating schedule and associated personnel. Most such systems do not have the computing power to decode in software when the decoding must be performed for each received pulse, as is required for certain sets of phase codes. These sets provide the best signal to sidelobe ratio when operating at the minimum band length allowed by the bandwidth of the transmitter. The development of the hardware phase decoder, and the applicability of each to decoding MST radar signals are discussed. A new design for a decoder which is very inexpensive to build, easy to add to an existing system and is capable of decoding on each received pulse using codes with a band length as short as one microsecond is presented

Towards a practical guide for developing knowledge management systems in small organizations.

There is no common method for developing KMS in organizations; practice is dominated by proprietary and ad hoc approaches and is often oriented towards information systems development. Currently KMS development (KMSD) omits the creation of KM cultures in unique organizational contexts, how to ‘operationalize’ knowledge, and how to support KMS with appropriate technologies. The paper provides practical insights via explanatory elements of a guide for a principled and useful KMSD approach, one which is adaptable for the complex situations of constantly and unpredictably changing environments and specific settings and needs of organizations. The guide’s concepts and approach have emerged from and been validated in practice by an inquiry into a number of problems experienced by particular organizations. For practitioners the paper presents insights into how to develop KMS that address organizational needs. For scholars our guide to a KMSD approach addresses calls in the literature for empirical research into the deployment of KMS and the role of IT in supporting KMS

Profile of ipilimumab and its role in the treatment of metastatic melanoma

Melanoma is an immunogenic cancer. However, the ability of the immune system to eradicate melanoma tumors is affected by intrinsic negative regulatory mechanisms. Multiple immune-modulatory therapies are currently being developed to optimize the immune response to melanoma tumors. Two recent Phase III studies using the monoclonal antibody ipilimumab, which targets the cytotoxic T-lymphocyte antigen (CTLA-4), a negative regulator of T-cell activation, have demonstrated improvement in overall survival of metastatic melanoma patients. This review highlights the clinical trial data that supports the efficacy of ipilimumab, the immune-related response criteria used to evaluate clinical response, and side-effect profile associated with ipilimumab treatment

Who comes back with what: a retrospective database study on reasons for emergency readmission to hospital in children and young people in England

OBJECTIVE: To determine the proportion of children and young people (CYP) in England who are readmitted for the same condition. DESIGN: Retrospective cohort study. SETTING: National administrative hospital data (Hospital Episode Statistics). PARTICIPANTS: CYP (0-year-olds to 24-year-olds) discharged after an emergency admission to the National Health Service in England in 2009/2010. MAIN OUTCOME MEASURES: Coded primary diagnosis classified in six broad groups indicating reason for admission (infection, chronic condition, injury, perinatal related or pregnancy related, sign or symptom or other). We grouped readmissions as ≤30 days or between 31 days and 2 years after the index discharge. We used multivariable logistic regression to determine factors at the index admission that were predictive of readmission within 30 days. RESULTS: 9% of CYP were readmitted within 30 days. Half of the 30-day readmissions and 40% of the recurrent admissions between 30 days and 2 years had the same primary diagnosis group as the original admission. These proportions were consistent across age, sex and diagnostic groups, except for infants and young women with pregnancy-related problems (15-24 years) who were more likely to be readmitted for the same primary diagnostic group. CYP with underlying chronic conditions were readmitted within 30 days twice as often (OR: 1.93, 95% CI 1.89 to 1.99) compared with CYP without chronic conditions. CONCLUSIONS: Financial penalties for readmission are expected to incentivise more effective care of the original problem, thereby avoiding readmission. Our findings, that half of children come back with different problems, do not support this presumption

Health outcomes, healthcare use and development in children born into or growing up in single-parent households: a systematic review study protocol

INTRODUCTION: Up to a quarter of all children globally live in single-parent households. Studies have concluded that children who grow up with continuously married parents have better health outcomes than children who grow up with single or separated parents. This is consistent for key health and development outcomes including physical health, psychological well-being and educational attainment. Possible explanations include higher poverty and time limitations of parental engagement within single-parent families, but these only represent a narrow range of mechanisms. We aim to identify and synthesise the evidence on how being born into and/or living in a single-parent household compared with living in a two-parent household as a child impacts health and development outcomes, healthcare use and factors that may be driving differences. METHODS AND ANALYSIS: We will search PubMed, Scopus and ERIC and adapt our search terms for search engines and grey literature sites to include relevant conference abstracts and grey literature. We will restrict results to English language publications from 2000 to 2020 and screen against inclusion criteria. We will categorise main outcomes into five groups of outcomes: birth outcomes, mortality, physical health, mental health and development, and healthcare use. We will use the Newcastle-Ottawa Scale to assess the methodological quality of studies. Narrative synthesis will form the primary analysis in the review. Synthesis of effect estimates without meta-analysis will follow the Synthesis Without Meta-analysis guidelines. ETHICS AND DISSEMINATION: All documents used are publicly accessible. We will submit results to a peer-reviewed journal and international social science conferences. We will communicate results with single-parent groups and relevant charitable organisations. This review will also be included in IL's PhD thesis. PROSPERO REGISTRATION NUMBER: CRD42020197890

A typology of longitudinal integrated clerkships

Context Longitudinal integrated clerkships (LICs) represent a model of the structural redesign of clinical education that is growing in the USA, Canada, Australia and South Africa. By contrast with time‐limited traditional block rotations, medical students in LICs provide comprehensive care of patients and populations in continuing learning relationships over time and across disciplines and venues. The evidence base for LICs reveals transformational professional and workforce outcomes derived from a number of small institution‐specific studies. Objectives This study is the first from an international collaborative formed to study the processes and outcomes of LICs across multiple institutions in different countries. It aims to establish a baseline reference typology to inform further research in this field. Methods Data on all LIC and LIC‐like programmes known to the members of the international Consortium of Longitudinal Integrated Clerkships were collected using a survey tool developed through a Delphi process and subsequently analysed. Data were collected from 54 programmes, 44 medical schools, seven countries and over 15 000 student‐years of LIC‐like curricula. Results Wide variation in programme length, student numbers, health care settings and principal supervision was found. Three distinct typological programme clusters were identified and named according to programme length and discipline coverage: Comprehensive LICs; Blended LICs, and LIC‐like Amalgamative Clerkships. Two major approaches emerged in terms of the sizes of communities and types of clinical supervision. These referred to programmes based in smaller communities with mainly family physicians or general practitioners as clinical supervisors, and those in more urban settings in which subspecialists were more prevalent. Conclusions Three distinct LIC clusters are classified. These provide a foundational reference point for future studies on the processes and outcomes of LICs. The study also exemplifies a collaborative approach to medical education research that focuses on typology rather than on individual programme or context