Memorial University of Newfoundland

About: Memorial University of Newfoundland is a education organization based out in St. John's, Newfoundland and Labrador, Canada. It is known for research contribution in the topics: Population & Gadus. The organization has 13818 authors who have published 27785 publications receiving 743594 citations. The organization is also known as: Memorial University & Memorial University of Newfoundland and Labrador.

Survey of automatic modulation classification techniques: classical approaches and new trends

Abstract: The automatic recognition of the modulation format of a detected signal, the intermediate step between signal detection and demodulation, is a major task of an intelligent receiver, with various civilian and military applications. Obviously, with no knowledge of the transmitted data and many unknown parameters at the receiver, such as the signal power, carrier frequency and phase offsets, timing information and so on, blind identification of the modulation is a difficult task. This becomes even more challenging in real-world scenarios with multipath fading, frequency-selective and time-varying channels. With this in mind, the authors provide a comprehensive survey of different modulation recognition techniques in a systematic way. A unified notation is used to bring in together, under the same umbrella, the vast amount of results and classifiers, developed for different modulations. The two general classes of automatic modulation identification algorithms are discussed in detail, which rely on the likelihood function and features of the received signal, respectively. The contributions of numerous articles are summarised in compact forms. This helps the reader to see the main characteristics of each technique. However, in many cases, the results reported in the literature have been obtained under different conditions. So, we have also simulated some major techniques under the same conditions, which allows a fair comparison among different methodologies. Furthermore, new problems that have appeared as a result of emerging wireless technologies are outlined. Finally, open problems and possible directions for future research are briefly discussed.

The 2011 Report on Dietary Reference Intakes for Calcium and Vitamin D From the Institute of Medicine: What Clinicians Need to Know

Abstract: This report summarizes the findings of the 2011 Institute of Medicine Committee on dietary intake requirements for calcium and vitamin D in North America, and provides updated data from the previous Institute of Medicine report of 1997. The Committee extensively reviewed existing published evidence on dietary and supplemental intake requirements for calcium and vitamin D with respect to both skeletal health and extraskeletal chronic disease outcomes. Calcium and vitamin D intake requirements were examined for several risk indictors of bone and skeletal health as well as extraskeletal outcomes (including cancer, cardiovascular disease, diabetes, and autoimmune disorders, infectious diseases, neuropsychological function, and disorders of pregnancy). Recommended Dietary Allowance (RDA) was defined as the level of intake of calcium or serum 25-hydroxyvitamin D that would meet the requirements of at least 97.5% of the population. The available scientific data supported an important role for calcium and vitamin D in bone and skeletal health outcomes that was consistent with a cause-and-effect relationship. However, data from randomized clinical trials for extraskeletal health outcomes were limited and inconclusive regarding a possible relationship with calcium and vitamin D intake requirements, and no evidence was found for dose-response or other established criteria for cause-and-effect. For bone health outcome, RDAs of calcium ranged from 700 to 1300 mg/d for life-stage groups at ≥1 year of age, and RDAs of vitamin D were 600 IU/d for ages 1 to 70 years and 800 IU/d for ages ≥71 (corresponding to a serum 25-hydroxyvitamin D level of at least 20 ng/mL [50 nmol/L]). There was an assumption of minimal or no sun exposure for estimation of RDA levels because of the wide variation in vitamin D synthesis from ultraviolet light and concern over risk of skin cancer. No consistent evidence was found that dietary or supplemental intake of vitamin D levels above the RDA provides additional benefit for bone health or extraskeletal outcomes; several investigators have found an U-shaped curve for several outcomes related to vitamin D intake, with increased risks at both low and high levels. The findings of this report suggest that prevalence of vitamin D deficiency in North America has been overestimated. The data show that almost all individuals in this population meet their RDA for vitamin D.

Genetic Mapping of a Locus Predisposing to Human Colorectal Cancer

Abstract: Genetic linkage analysis was used to determine whether a specific chromosomal locus could be implicated in families with a history of early onset cancer but with no other unique features. Close linkage of disease to anonymous microsatellite markers on chromosome 2 was demonstrated in two large kindreds. The pairwise lod scores for linkage to marker D2S123 in these kindreds were 6.39 and 1.45 at zero recombination, and multipoint linkage with flanking markers resulted in lod scores of 6.47 and 6.01. These results prove the existence of a genetically determined predisposition to colorectal cancer that has important ramifications for understanding and preventing this disease.