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 & Context (language use). 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.

Antioxidant and antiradical activities in extracts of hazelnut kernel (Corylus avellana L.) and hazelnut green leafy cover.

Abstract: Phenolic compounds in the aqueous systems were extracted, from hazelnut kernel (HK) and hazelnut green leafy cover (HGLC), with 80% (v/v) ethanol (HKe and HGLCe) or 80% (v/v) acetone (HKa and HGLCa). The extracts were examined for their phenolic and condensed tannin contents and phenolic acid profiles (free and esterified fractions) as well as antioxidant and antiradical activities by total antioxidant activity (TAA), antioxidant activity in a beta-carotene-linoleate model system, scavenging of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, and reducing power. Significant differences (p HGLCe > HKa > HKe. These results suggest that both 80% ethanol and acetone are capable of extracting phenolics, but 80% acetone was a more effective solvent for the extraction process. HGLC exhibited stronger antioxidant and antiradical activities than HK itself in both extracts and could potentially be considered as an inexpensive source of natural antioxidants.

Effect of feeding whey hydrolysate soy and conventional cow milk formulas on incidence of atopic disease in high risk infants.

Abstract: The effect of feeding different infant formulas on incidence of atopic disease was assessed in a prospective double-blind randomized controlled trial among "high risk" infants with family history of atopy among first-degree relatives The incidence of atopic eczema, wheezing, rhinitis, gastrointestinal symptoms, and colic was noted and serum IgE antibodies to milk were estimated Seventy-two infants were recruited into each of the following groups: cow milk whey hydrolysate formula (NAN/HA), conventional cow milk formula (Similac), soy-based formula (Isomil), and exclusive breast feeding for greater than or equal to 4 months The number of infants who exited for reasons other than atopy and were excluded from analysis were 4, 5, 4, and 12 in the four groups, respectively The incidence of one or more symptoms of possible allergic etiology was five of 68 infants fed NAN/HA, 24 of 67 infants fed Similac, 25 of 68 infants fed Isomil, and 12 of 60 breast-fed infants Among symptomatic infants, skin prick test to milk proteins was positive in four out of five infants fed NAN/HA, 16 of 24 fed Similac, 2 of 25 fed Isomil, and 7 of 12 breast-fed IgE antibodies to milk were found in 2 of 68, 9 of 67, 0 of 68, and 6 of 60 infants in the four groups, respectively It is concluded that exclusive breast feeding for more than 4 months is partially protective against the development of atopic disease among high risk infants(ABSTRACT TRUNCATED AT 250 WORDS)

Resonant scattering of outer zone relativistic electrons by multiband EMIC waves and resultant electron loss time scales

Abstract: To improve our understanding of the role of electromagnetic ion cyclotron (EMIC) waves in radiation belt electron dynamics, we perform a comprehensive analysis of EMIC wave-induced resonant scattering of outer zone relativistic (>0.5 MeV) electrons and resultant electron loss time scales with respect to EMIC wave band, L shell, and wave normal angle model. The results demonstrate that while H+-band EMIC waves dominate the scattering losses of ~1–4 MeV outer zone relativistic electrons, it is He+-band and O+-band waves that prevail over the pitch angle diffusion of ultrarelativistic electrons at higher energies. Given the wave amplitude, EMIC waves at higher L shells tend to resonantly interact with a larger population of outer zone relativistic electrons and drive their pitch angle scattering more efficiently. Obliquity of EMIC waves can reduce the efficiency of wave-induced relativistic electron pitch angle scattering. Compared to the frequently adopted parallel or quasi-parallel model, use of the latitudinally varying wave normal angle model produces the largest decrease in H+-band EMIC wave scattering rates at pitch angles ~5 MeV. At a representative nominal amplitude of 1 nT, EMIC wave scattering produces the equilibrium state (i.e., the lowest normal mode under which electrons at the same energy but different pitch angles decay exponentially on the same time scale) of outer belt relativistic electrons within several to tens of minutes and the following exponential decay extending to higher pitch angles on time scales from <1 min to ~1 h. The electron loss cone can be either empty as a result of the weak diffusion or heavily/fully filled due to approaching the strong diffusion limit, while the trapped electron population at high pitch angles close to 90° remains intact because of no resonant scattering. In this manner, EMIC wave scattering has the potential to deepen the anisotropic distribution of outer zone relativistic electrons by reshaping their pitch angle profiles to “top-hat.” Overall, H+-band and He+-band EMIC waves are most efficient in producing the pitch angle scattering loss of relativistic electrons at ~1–2 MeV. In contrast, the presence of O+-band EMIC waves, while at a smaller occurrence rate, can dominate the scattering loss of 5–10 MeV electrons in the entire region of the outer zone, which should be considered in future modeling of the outer zone relativistic electron dynamics.

A method to increase contaminant tolerance in protein matrix‐assisted laser desorption/ionization by the fabrication of thin protein‐doped polycrystalline films

Abstract: This paper describes the fabrication and use of thin polycrystalline films in matrix-assisted laser desorption experiments. These films consist of microcrystals of protein-doped matrix (crystal dimensions ⩽ 1 μm). The films produce intense protein-ion currents and can be grown in the presence of high concentrations of involatile solvents (e.g., glycerol, 6 M urea) without any purification. They strongly adhere to the substrate, allowing easier washing of the film, compared to dried-droplet deposits. The films are also more uniform than dried-droplet deposits, with respect to ion production. It is suggested that matrix-assisted laser desorption/ionization samples are composed of nonlinear optical devices that function as polymer ion-current sources. These devices (protein-doped matrix crystals) can be designed and fabricated in many forms to serve the special functions required by the analytical scientist.

Signal identification for emerging intelligent radios: classical problems and new challenges

Abstract: Signal identification, which initially found applications in electronic warfare and spectrum monitoring and surveillance, has been recently considered for commercial communications in the context of software defined and cognitive radios. In this article, I present a snapshot of the status of signal identification algorithms, starting from a general description of maximum likelihood (ML) and feature based (FB) approaches to a more detailed discussion of a practical methodology using cyclostationarity-based features. I discuss the cyclostationarity-based features of various signals and the criteria of decision for their identification, while considering classical problems of identifying single carrier linearly digitally (SCLD) modulated signals, as well as new challenges posed by the identification of orthogonal frequency division multiplexing (OFDM), SC frequency domain equalization (SC-FDE), and multiple-transmit antenna signals. I conclude the article with remarks on practical solutions to signal identification and open research issues.