1,462 research outputs found

    A method to correct differential nonlinearities in subranging analog-to-digital converters used for digital gamma-ray spectroscopy

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    The influence on γ\gamma-ray spectra of differential nonlinearities (DNL) in subranging, pipelined analog-to-digital converts (ADCs) used for digital γ\gamma-ray spectroscopy was investigated. The influence of the DNL error on the γ\gamma-ray spectra, depending on the input count-rate and the dynamic range has been investigated systematically. It turned out, that the DNL becomes more significant in γ\gamma-ray spectra with larger dynamic range of the spectroscopy system. An event-by-event offline correction algorithm was developed and tested extensively. This correction algorithm works especially well for high dynamic ranges

    Shrimps of the genus Periclimenes (Crustacea, Decapoda, Palaemonidae) associated with mushroom corals (Scleractinia, Fungiidae): Linking DNA barcodes to morphology

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    Most marine palaemonid shrimp species live in symbiosis with invertebrates of various phyla. These associations range from weak epibiosis to obligatory endosymbiosis and from restricted commensalism to semi-parasitism. On coral reefs, such symbiotic shrimps can contribute to the associated biodiversity of reef corals. Among the host taxa, mushroom corals (Cnidaria: Anthozoa: Fungiidae) are known to harbour various groups of symbionts, including shrimps. Some but not all of these associated species are host-specific. Because data on the host specificity of shrimps on mushroom corals are scarce, shrimp species of the genus Periclimenes were collected from mushroom corals during fieldwork in Lembeh Strait, North Sulawesi, Indonesia. Using molecular (COI barcoding gene) and morphological methods, three species of Periclimenes were identified: P. diversipes, P. watamuae and a species new to science, P. subcorallum sp. nov., described herein. Their host specificity was variable, with eight, three and two fungiid host records, respectively. It is concluded that shrimp species of the genus Periclimenes show much overlap in their host choice and that particular morphological traits in the host species appear to play a more important role than phylogenetic affinities within the host group.publishedVersio

    Age-Related Health Hazards in Old Patients with First-Time Referral to a Rheumatologist: A Descriptive Study

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    Objective. To study the prevalence of generic age-related health hazards in elderly patient referred to a rheumatologist. Methods. Patients aged 75 or older referred to a specialized gerontorheumatological outpatient service over a period of 2 years were studied prospectively to determine the prevalence of comorbidities, a history of falls, inactivity, cognitive dysfunction, loneliness, and depression in this patient group. Results. A group of 154 patients were included in the study. Comorbidities were observed in 88% of the patients. At least one fall was reported in the last year by 44% of the patients; 44% of the patients reported low levels of health-enhancing physical activity. Depressed mood and loneliness were elevated in 30% and 31% of the patients, respectively. Mild or moderate cognitive impairment was observed in 13% of the patients. Conclusion. Patients in this study were characterized by poor physical ability, high levels of pain, and high prevalence of age-related health hazards

    Hip osteoarthritis: patients with complex comorbidities can make exceptional improvements following intensive exercise and education.

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    A 71-year-old man presenting with hip osteoarthritis, with a complex range of comorbidities was referred by his general practitioner to CHAIN (Cycling against Hip PAIN), a 6 week programme developed to aid self-management of hip osteoarthritis through exercise, education and advice, as defined by the National Institute for Health and Care Excellence (NICE) guidelines. Significant improvements were seen in Oxford hip score, the Hip disability and Osteoarthritis Outcome Score (HOOS) - function score, sit-to-stand test, timed up and go test, pain scores and hip flexion. There was also a weight loss of 2.1 kg. The man reported 'an amazing difference' in his affected hip and leg, and improved fitness. Many clinicians would have questioned the man's suitability for the programme due to his coexisting medical conditions. This case study shows that patients may be much more able than we think to achieve significant improvement with exercise

    Identification of mixed-symmetry states in an odd-mass nearly-spherical nucleus

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    The low-spin structure of 93Nb has been studied using the (n,n' gamma) reaction at neutron energies ranging from 1.5 to 3.0 MeV and the 94Zr(p,2n gamma)93Nb reaction at bombarding energies from 11.5 to 19 MeV. States at 1779.7 and 1840.6 keV, respectively, are proposed as mixed-symmetry states associated with the coupling of a proton hole in the p_1/2 orbit to the 2+_1,ms state in 94Mo. These assignments are derived from the observed M1 and E2 transition strengths to the symmetric one-phonon states, energy systematics, spins and parities, and comparison with shell model calculations.Comment: 5 pages, 3 figure

    Effect of feed ingredients on nutrient digestibility, waste production and physical characteristics of rainbow trout (Oncorhynchus mykiss) faeces.

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    This study assessed the effect of different dietary ingredients on the quantity and characteristics of faecal waste produced by rainbow trout (Oncorhynchus mykiss). Seven ingredients were tested: fish meal (FM), mussel meal (MM), poultry meal wet rendered (PM-W) or dry rendered (PM-D), insect meal (IM), single cell protein (SCP) and brewers grain protein (BGP). Eight experimental diets were formulated: a control diet (CON) being predominantly plant-based and seven test diets, which contained 70% of the CON diet and 30% of one of the test ingredients. Rainbow trout juveniles (65 g, 30 fish/tank) were fed the experimental diets at satiation for six weeks in triplicate groups. Dry matter (DM) and nutrient digestibility of diets and the test ingredients were measured. To estimate the faecal characteristics, particle size distribution (PSD) and removal efficiency of the faecal waste was determined. Nutrient digestibility of diets and ingredients differed significantly. Growth did not differ between the experimental diets, but DM digestibility was affected by the diet. Diets affected the amount of faecal waste produced, its removal efficiency (%) and the amount of non-removed faeces (g DM/kg DM feed). The highest and lowest removal efficiency was observed at FM and BGP diets, respectively. Accordingly, FM diet resulted in the lowest (37 g DM/kg DM feed), while BGP diet resulted in the highest (125 g DM/kg DM feed) amount of non-removed faeces. Additionally, it was also observed that differences in faecal removal efficiency can compensate for the variation in the quantity of faecal waste produced. Consistent with the faecal removal efficiency data, faeces PSD was also influenced by diets. FM and MM diets resulted in faeces with the lowest proportion of particles of <40 μm size, while BGP diet had the largest proportion of faecal particles of this size range. Furthermore, the effect of dietary ingredient composition was evident in the stability of faeces, with FM producing the most stable, whereas CON, BGP and SCP diets resulting in relatively unstable faecal pellets. In addition, due to differences in inclusion level of nutrients and their corresponding digestibility, the chemical composition of faeces differed between the diets. Overall, the study showed that dietary ingredient composition influences nutrient digestibility and is an important factor determining the amount of faecal waste produced, its removal efficiency, PSD, stability and composition in rainbow trout.publishedVersio

    Single-conformation spectroscopy of hydrogen bonding networks: Solvation, synthetic foldamers, and neurodegenerative diseases

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    The hydrogen bond is one of the most important interactions in natural processes ranging from protein folding to chemical reactions. Two complementary methodologies are applied to understanding this important interaction: top-down and bottom-up. Top-down methods use large molecules, such as proteins, revealing secondary structure information. Bottom-up experiments are performed on small molecules, utilizing high-resolution spectroscopy to reveal underlying quantum mechanical effects. The complexity gap is formed between these two experimental regimes; between large and small molecules; between bulk and individual solvent molecules; between classical mechanics calculations and quantum chemical calculations. This dissertation will focus on the application of gas phase, single-conformation ultraviolet (UV) and infrared (IR) spectroscopies to the study of molecules and clusters in the size and solvation complexity gap, with the goal of bridging the gulf between the two experimental approaches. Single-conformation spectroscopy is perfectly suited to study solvation. Solvent molecules, in many instances water, can be frozen onto the solute in a stepwise manner. Here, we solvate a prototypical flexible bichromophore—1,2-diphenoxyethane (DPOE)—by stepwise addition of water molecules. Single-conformation spectroscopy reveals both the structural perturbations associated with water molecule addition and their effect on DPOE’s pair of closely spaced excited electronic states. These experimental studies provide excellent insight into solvent effects on vibronic and excitonic coupling, and can be used to further develop the models used to describe such processes. Similarly, single-conformation spectroscopy can reveal the effects of conformational flexibility on the innate conformational preferences and hydrogen bonding motifs in peptides. Results obtained from a study of a cyclically constrained γ peptide, γACHC, reveal that increased conformational flexibility can be controlled by synthetic chemists in order to direct folding into pre-programmed secondary structures and that these structures are stabilized with intramolecular rather than intermolecular hydrogen bonds. This theme of conformational flexibility is continued in studies of glutamine containing peptides. Glutamine—with its flexible, hydrogen bond forming sidechain—is intimately involved with neurodegenerative diseases such as Huntington’s disease. Single-conformation studies help reveal the delicate interplay between three different types of hydrogen bonds within the molecule: backbone-backbone, sidechain-backbone, and sidechain-sidechain hydrogen bonds. The importance of these competing hydrogen bonds on the conformational preferences will be discussed both locally and within the larger context of disease pathogenesis
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