112 research outputs found

    NMR Knight shifts and linewidths in the Ni‐Pd‐P and Ni‐Pt‐P metallic glasses: Composition and temperature dependences

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    NMR Knight shift and linewidth measurements are reported for the ^(31)P nuclei in the metallic glasses (Ni_(0.50)Pd_(0.50))100−_xP_x (where x=16 to 26.5) and (Ni_yPd_(1−y))_(80)P_(20) (where y=0.20 to 0.80), and both the ^(31)P and 195Pt nuclei in the metallic glass (Ni_yPt_(1−y))_(75)P_(25) (where y=0.20 to 0.68). The results are discussed in terms of the amorphous structure, electronic structure, and stability of transition metal + metalloid metallic glasses

    Psychological characteristics of developing excellence in elite youth football players in English professional academies

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    This mixed-longitudinal prospective study examined the development of psychological characteristics of developing excellence in relation to the career progression of elite youth football players. In a 20-month period, 111 academy football players aged 11-16 completed the Psychological Characteristics of Developing Excellence Questionnaire (PCDEQ) on 1-5 occasions. This combination of single and repeated assessments resulted in a mixed-longitudinal sample of 226 completed PCDEQs. Players were then prospectively tracked, and their scholarship status assessed at follow-up, at age U17. Multilevel modelling revealed that coping with performance and developmental pressures scores increased with age, and that Category 1-2 academy scholars (4.35 ± 0.61) scored higher than Category 3-4 academy scholars (3.99 ± 0.67) and non-scholars (4.02 ± 0.78) (p<.05). Evaluating performances and working on weaknesses scores increased with age for Category 1-2 academy scholars (U12-U14 vs. U15-U16 = 5.16 ± 0.48 vs. 5.38 ± 0.45), compared to non-scholars (U12-U14 vs. U15-U16 = 5.11 ± 0.59 vs. 5.03 ± 0.71) (p<.05). Imagery use during practice and competition scores decreased with age (U12-U14 vs. U15-U16 = 4.45 ± 0.66 vs. 4.29 ± 0.70) (p<.05). A blend of PCDEs may facilitate optimal career progression. Football academies should develop players’ PCDEs, with a particular focus on developing their coping skills and their ability to realistically evaluate performances and work on weaknesses

    Electronic structure of the Ni-Pd-P and Ni-Pt-P metallic glasses: A pulsed NMR study

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    A pulsed NMR and magnetic susceptibility study of the electronic structure is reported for the rapidly quenched metallic glass systems: (Ni0.50Pd0.50)100-xPx (where 16≦x≦26.5), (NiyPd1-y)80P20 (where 0.20≦y≦0.80), and (NiyPt1-y)75P25 (where 0.20≦y≦0.68). The 31P Knight shift and nuclear spin-lattice relaxation rate in all three systems depend only on the P concentration, x, and not the Ni concentration, y, nor whether the second transition metal is Pd or Pt. Both the shift and relaxation rate for 31P are attributed solely to the direct contact hyperfine interaction. The 195Pt Knight shift and magnetic susceptibility for (NiyPt1-y)75P25 do depend on both the Ni concentration and temperature, enabling a determination of the contributions to the shift arising from the direct contact hyperfine and core polarization interactions. The results are discussed in terms of a rigid two-band picture with estimates being made for the s- and d-band densities of states and hyperfine coupling constants. There is strong evidence for a transfer of charge from the P metalloid atoms (M) to the d states of the transition-metal atoms (T), which is consistent with the dense random packing model for T100-xMx metallic glasses

    Are nematodes costly to fig tree–fig wasp mutualists?

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    Most mutualisms are exploited by parasites, which must strike an evolutionary balance between virulence and long‐term persistence. Fig‐associated nematodes, living inside figs and dispersed by fig wasps, are thought to be exploiters of the fig–fig wasp mutualism. The life history of nematodes is synchronized with the fig development and adapted to particular developmental characteristics of figs. We expect host breeding systems (monoecious vs. gynodioecious figs) and seasonality to be central to this adaptation. However, the details of the adaptation are largely unknown. Here, we conducted the first field surveys on the prevalence of nematodes from monoecious Ficus microcarpa L.f. (Moraceae), gynodioecious Ficus hispida L.f., and their pollinating fig wasps in two seasons and two developmental stages of figs in Xishuangbanna, China. We followed this up by quantifying the effects of nematodes on fitness‐related traits on fig wasps (e.g., egg loads, pollen grains, and longevity) and fig trees (seed production) in gynodioecious F. hispida. The magnitude of nematode infection was compared between pre‐ and post‐dispersal pollinators to quantify the probability of nematodes being transported to new hosts. Our results showed that Ficophagus microcarpus (Nematoda: Aphelenchoididae) was the only nematode in F. microcarpa. In F. hispida, Martininema guangzhouensis (Nematoda: Aphelenchoididae) was the dominant nematode species, whereas Ficophagus centerae was rare. For both species of Ficus, rainy season and inter‐floral figs had higher rates of nematode infection than the dry‐hot season and receptive figs. Nematodes did not affect the number of pollen grains or egg loads of female wasps. We did not detect a correlation between seed production and nematode infection. However, carrying nematodes reduced the lifespan and dispersal ability of pollinator wasps, indicating higher rates of post‐emergence mortality in infected fig wasps. Severely infected fig wasps were likely ‘filtered out’, preventing the overexploitation of figs by wasps and stabilizing the interaction over evolutionary time

    The effect of stress and anxiety associated with maternal prenatal diagnosis on feto-maternal attachment

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    <p>Abstract</p> <p>Background</p> <p>A couple's decision to undergo an invasive test based on a screening test result is a process associated with anxiety. The aim of this study was to determine whether anxiety and prenatal attachment were affected by undergoing an invasive test compared to women in early pregnancy and after a reassuring anomaly scan.</p> <p>Methods</p> <p>200 women were recruited at booking, 14 women and 20 partners after an invasive test and 81 women following an anomaly scan. A questionnaire was completed using the Beck Anxiety Inventory and Maternal or Paternal Antenatal Attachment Scales.</p> <p>Results</p> <p>Women who have had an invasive test have higher levels of anxiety compared to women at booking (P < 0.01) and after an anomaly scan (P = 0.002). Anxiety declines from booking to the time of an anomaly scan (P = 0.025), whilst attachment increases (P < 0.001). There is a positive correlation between anxiety and attachment in women who have had an invasive test (r = 0.479). Partners of women undergoing an invasive test experience lower levels of anxiety (P < 0.05).</p> <p>Conclusions</p> <p>Women undergoing prenatal diagnostic procedures experience more psychological distress, which may be currently underestimated. Establishment of interdisciplinary treatment settings where access to psychological support is facilitated may be beneficial.</p

    Is the beck anxiety inventory a good tool to assess the severity of anxiety? A primary care study in The Netherlands study of depression and anxiety (NESDA)

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    <p>Abstract</p> <p>Background</p> <p>Appropriate management of anxiety disorders in primary care requires clinical assessment and monitoring of the severity of the anxiety. This study focuses on the Beck Anxiety Inventory (BAI) as a severity indicator for anxiety in primary care patients with different anxiety disorders (social phobia, panic disorder with or without agoraphobia, agoraphobia or generalized anxiety disorder), depressive disorders or no disorder (controls).</p> <p>Methods</p> <p>Participants were 1601 primary care patients participating in the Netherlands Study of Depression and Anxiety (NESDA). Regression analyses were used to compare the mean BAI scores of the different diagnostic groups and to correct for age and gender.</p> <p>Results</p> <p>Patients with any anxiety disorder had a significantly higher mean score than the controls. A significantly higher score was found for patients with panic disorder and agoraphobia compared to patients with agoraphobia only or social phobia only. BAI scores in patients with an anxiety disorder with a co-morbid anxiety disorder and in patients with an anxiety disorder with a co-morbid depressive disorder were significantly higher than BAI scores in patients with an anxiety disorder alone or patients with a depressive disorder alone. Depressed and anxious patients did not differ significantly in their mean scores.</p> <p>Conclusions</p> <p>The results suggest that the BAI may be used as a severity indicator of anxiety in primary care patients with different anxiety disorders. However, because the instrument seems to reflect the severity of depression as well, it is not a suitable instrument to discriminate between anxiety and depression in a primary care population.</p

    Associations of familial risk factors with social fears and social phobia: evidence for the continuum hypothesis in social anxiety disorder?

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    We examined parental psychopathology and family environment in subthreshold and DSM-IV threshold conditions of social anxiety disorder (SAD) in a representative cohort sample of 1,395 adolescents. Offspring and parental psychopathology was assessed using the DIA-X/M-CIDI; recalled parental rearing and family functioning via questionnaire. Diagnostic interviews in parents were supplemented by family history reports from offspring. The cumulative lifetime incidence was 23.07% for symptomatic SAD, and 18.38 and 7.41% for subthreshold and threshold SAD, respectively. The specific parent-to-offspring association for SAD occurred for threshold SAD only. For subthreshold and threshold SAD similar associations were found with other parental anxiety disorders, depression and substance use disorders. Parental rearing behaviour, but not family functioning, was associated with offspring threshold SAD, and although less strong and less consistent, also with subthreshold SAD. Results suggest a continued graded relationship between familial risk factors and offspring SAD. Parental psychopathology and negative parental styles may be used defining high-risk groups to assign individuals with already subthreshold conditions of SAD to early intervention programs

    Microbial carcinogenic toxins and dietary anti-cancer protectants

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