This letter presents the design strategy and the experimental results on the Ku/Ka dual-band feed-horn developed within the Phase A/B1 study of the Copernicus imaging microwave radiometer, which is ...one of the new six expansion missions of the European Copernicus flagship program on Earth observation operating in five frequency channels. The radiometer requirements translate into a dense focal plane composed by compact and lightweight dual-band feed horns. The optimum illumination was derived in terms of Bloch waves and the applicability of piecewise-linear profile feed-horns for its synthesis in the case of two highly separated Ku--/Ka--frequency bands (1:1.95) was investigated. The presented feed-horn design was validated up to a technological readiness level of 6. The reported performances at antenna level for the complete Ku-/Ka-band feed cluster demonstrate the feasibility of dual-band smooth-wall feed-horns focal-planes meeting all the Earth observation requirements in terms of footprints, beam- and wide-beam efficiencies, and cross-polarization.
It is important to directly engage children and adolescents with disabilities (CAWD) in health promotion research to ensure their health needs are met. Arts-based research methods may help CAWD ...better express their ideas; photo-elicitation is one such technique, using self-captured photographs to enhance verbal descriptions of complex concepts. This review 1) summarizes findings from health promotion studies using photo-elicitation with CAWD; 2) explores benefits and challenges of using photo-elicitation; 3) identifies recommended photo-elicitation practices.
A scoping review was conducted using rapid review principles. Four health and social science databases were searched (2009-2019) using terms related to children, adolescents, disability, and photo-elicitation. Articles meeting inclusion criteria were summarized and analyzed thematically.
Eight studies met inclusion criteria and explored a range of health promotion topics. Benefits of photo-elicitation included the ability to mediate communication and direct participants' focus. Challenges included difficulty operating a camera and understanding instructions about photograph subject matter. Four recommended practices were identified: 1) brainstorming photograph ideas; 2) photograph-taking training; 3) having CAWD select photographs for discussion; 4) limiting the number of photographs CAWD could capture.
Integrating practices to support CAWD in using photo-elicitation can help researchers more fully understand their health experiences.
Implications for Rehabilitation
There is a need to directly engage children and adolescents with disabilities to express themselves in health promotion research.
The arts-based method of photo-elicitation may help children and adolescents with disabilities convey how they view and experience health.
Children and adolescents with disabilities may need supports, including camera training, to participate in photo-elicitation.
Aim: To explore the association between maternal dietary fat and fatty acid (FA) intake during lactation, and the risk of asthma in the offspring by the age of 5 years.
Methods: The subjects ...comprised 1798 mother–child pairs from the Type 1 Diabetes Prediction and Prevention (DIPP) Nutrition Study. Dietary intake was assessed by a validated 181‐item food frequency questionnaire, which covered the third month of lactation. The cumulative incidence of asthma was assessed at the age of 5 years with a questionnaire modified from the International Study of Asthma and Allergies in Childhood (ISAAC). Cox proportional hazards regression was used for statistical analysis.
Results: The maternal use of margarines during lactation was associated with a marginally increased risk of asthma hazard ratio (HR) for user vs. nonuser 1.96, 95% confidence interval (CI) 1.01–3.82, p = 0.047 after adjusting for putative confounders. The maternal intakes of n‐3 polyunsaturated FA (PUFA) and fish during lactation were not associated with the risk of asthma.
Conclusion: Maternal use of margarines during lactation was weakly associated with an increased risk of asthma in the offspring at the age of 5 years. Other fats or FAs during lactation were not associated with the risk of asthma. However, the nonadherence to dietary recommendations regarding especially fats of our study population may restrict the generalizability of our results.
Aims
We examined maternal dietary intake of fatty acids and foods which are sources of fatty acids during lactation and whether they are associated with the risk of preclinical and clinical type 1 ...diabetes in the offspring.
Methods
The subjects comprised a cohort of 2,939 mother–child pairs from the prospective Type 1 Diabetes Prediction and Prevention Study. Composition of maternal diet during the third month of lactation was assessed by a validated food frequency questionnaire. Among the children with HLA-conferred susceptibility to type 1 diabetes, 172 developed preclinical and 81 clinical diabetes. Average follow-up for preclinical type 1 diabetes was 7.5 years (range 0.2–14.0 years) and for clinical type 1 diabetes 7.7 years (0.2–14.0 years).
Results
Maternal intake of fatty acids during lactation was not associated with the risk of type 1 diabetes in the offspring. After adjusting for putative confounders, maternal total consumption of red meat and meat products during lactation was associated both with increased risk for preclinical hazard ratio (HR) 1.19, 95 % CI 1.02–1.40,
p
= 0.038 and clinical type 1 diabetes (HR 1.27, 95 % CI 1.06–1.52,
p
= 0.025). In particular, consumption of processed meat products showed an association with increased risk for type 1 diabetes (HR 1.23, 95 % CI 1.02–1.48,
p
= 0.045). Maternal use of vegetable oils was associated with increased risk for preclinical type 1 diabetes (HR 1.21, 95 % CI 1.03–1.41,
p
= 0.023).
Conclusions
Maternal consumption of red meat, especially processed meat, during lactation may increase the risk of type 1 diabetes.
Additive manufacturing technologies have been increasingly applied to the development of radio frequency components in the past few years. Indeed, the free-form capability of these processes allows ...for the design of novel components, whose actual implementation through conventional machining is rather complex or even not possible. This paper describes a monolithic WR51 component integrating three radio frequency functionalities, namely, bending, twisting, and filtering. Three aluminum prototypes with different bending/twisting radii have been manufactured through the selective laser melting process. They exhibit a measured rejection higher than 60 dB in 17.5 and 21.2 GHz, and a measured return loss better than 20 dB in 12.5 and 15 GHz. Significant mass and envelope reductions (higher than 60% depending on the bending/twisting radius) with respect to the reference subsystem with distinct waveguide components are achieved. These results assess the effectiveness of 3-D metal printing in the miniaturization and integration of waveguide systems.
In this paper, a Ka/K-band antenna-feeding network in dual-circular polarization is reported. The design of the system was carried out in view of its monolithic manufacturing through selective laser ...melting in AlSi10Mg alloy. As a proof-of-concept for satellite telecommunication multi-beam applications, the feeding network operates in the K band (19.25, 20.75) GHz and in the Ka band (27.0, 29.0) GHz. The system provides four rectangular-waveguide ports and a common dual-polarized circular-waveguide port to be connected to the feed horn. The prototype exhibits measured values of in-band return loss better than 28 dB and a port-to-port isolation better than 19 dB (in polarization) and 50 dB (in frequency). The cross-polar discrimination is higher than 20 dB. In this regard, an elliptical-waveguide line was specifically designed and manufactured to recover a value higher than 30 dB in both frequency bands. The line can be easily integrated in the feed horn to be connected to the feeding-network thanks the ease of customization provided by 3D printing. The insertion losses are lower than 0.5 and 0.2 dB in the K and Ka bands, respectively. The weight of the prototype is approximately 130 g.
Additive manufacturing technologies have been increasingly applied to the development of radio frequency components in the past few years. Indeed, the free-form capability of these processes allows ...for the design of novel components, whose actual implementation through conventional machining is rather complex or even not possible. This paper describes a monolithic WR51 component integrating three radio frequency functionalities, namely, bending, twisting, and filtering. Three aluminum prototypes with different bending/twisting radii have been manufactured through the selective laser melting process. They exhibit a measured rejection higher than 60 dB in 17.5 and 21.2 GHz, and a measured return loss better than 20 dB in 12.5 and 15 GHz. Significant mass and envelope reductions (higher than 60% depending on the bending/twisting radius) with respect to the reference subsystem with distinct waveguide components are achieved. These results assess the effectiveness of 3-D metal printing in the miniaturization and integration of waveguide systems.
Lumia et al discuss Murthy and colleagues' commentary highlighting the need to improve Canada's current research infrastructure to support national clinical research studies. Murthy and colleagues ...note Canada's limited ability to rapidly conduct high-priority research, hindered by the need for separate data-sharing agreements and ethics review at each participating hospital site. They experienced long delays (6 mo to more than 1 yr) in receiving ethics and institutional approvals to conduct our low-risk, multisite observational study evaluating the long-term effects of COVID-19. The main factors that contributed to approval delays included the establishment and approval of data-sharing agreements at each of our 11 study sites (across 6 provinces) and separate, full-board ethics review at 5 study sites. Differences in local requirements for information technology and online security, collection of personal health data, recruitment processes, and data storage and retention also contributed to approval delays.
The majority of commercial heavy-lift Unmanned Aerial Vehicles (UAVs) is equipped with carbon fiber propellers. This paper analyzes the impact of such conductive rotating parts on UAV-based antenna ...measurements in the VHF band. The simulated results show a significant increase of both measurement noise and systematics.