535 research outputs found
Large and Small Polaron Excitations in La2/3(Sr/Ca)1/3MnO3 Films
We present detailed optical measurements of the mid-infrared (MIR)
excitations in thin films of La2/3Sr1/3MnO3 (LSMO) and La2/3Ca1/3MnO3 (LCMO)
across the magnetic transition. The shape of the excitation at about 0.2 eV in
both samples is analyzed in terms of polaron models. We propose to identify the
MIR resonance in LSMO as the excitation of large polarons and that in LCMO as a
small polaron excitation. A scaling behavior for the low-energy side of the
polaronic MIR resonance in LSMO is established
Socio-cultural factors for breastfeeding cessation and their relationship with child diarrhoea in the rural high-altitude Peruvian Andes - a qualitative study
BACKGROUND: In some areas of the world, breast milk is seen as a potential source of child diarrhoea. While this belief has been explored in African and Southeast Asian countries, it remains vastly understudied in Latin American contexts. We investigate socio-cultural factors contributing to breastfeeding cessation in rural high-altitude populations of the Peruvian Andes. The role of socio- cultural factors in the local explanatory model of child diarrhoea, and whether these perceptions were integrated in the local healthcare system were assessed. METHODS: Within the framework of a randomised controlled trial, we conducted semi-structured interviews with 40 mothers and 15 health personnel from local healthcare centres involved in the trial. RESULTS: Cultural beliefs on breastfeeding cessation included the perception that breast milk turned into "blood" after six months and that breastfeeding caused child diarrhoea. We identified eight local types of child diarrhoea, and women linked six of them with breastfeeding practices. "Infection" was the only diarrhoea mothers linked to hygiene and the germ disease concept and perceived as treatable through drug therapy. Women believed that other types of diarrhoea could not be treated within the formal healthcare sector. Interviews with health personnel revealed no protocol for, or consensus about, the integration of the local explanatory model of child diarrhoea in local healthcare and service provision. CONCLUSIONS: The local explanatory model in rural Andean Peru connected breastfeeding with child diarrhoeas. Cultural beliefs regarding diarrhoea management may increase home treatments, even in cases of severe diarrhoeal episodes. Future national breastfeeding support programmes should promote peer-counselling approaches to reduce negative attitudes towards breastfeeding and health practitioners. Local explanatory models should be incorporated into provincial and regional strategies for child diarrhoea management to promote equity in health and improve provider-patient relationships
Survey of the ULF wave Poynting vector near the Earth's magnetic equatorial plane
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101878/1/pdfexplain.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101878/2/jgra50591.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101878/3/pdfexplain.tx
The development of RAPTA compounds for the treatment of tumors
© 2015 Elsevier B.V. Ruthenium(II)-arene RAPTA-type compounds have been extensively explored for their medicinal properties. Herein a comprehensive review of this class of compounds is provided. A discussion of the basic RAPTA structure is given together with the ways it has been modified to elucidate the key role of each part and to afford targeted derivatives. The various mechanistic studies conducted on RAPTA compounds are described and these are linked to the observed macroscopic biological properties. Ultimately, the review shows that certain RAPTA compounds display quite unique properties that point towards a clinical investigation
Effectiveness of a home-environmental intervention package and an early child development intervention on child health and development in high-altitude rural communities in the Peruvian Andes: a cluster-randomised controlled trial
Unsafe drinking water, poor sanitation and hygiene, exposure to household air pollution and low cognitive and socio-emotional stimulation are risk factors affecting children in low- and middle-income countries. We implemented an integrated home-environmental intervention package (IHIP), comprising a kitchen sink, hygiene education and a certified improved biomass cookstove, and an early child development (ECD) programme to improve childrenÂŽs health and developmental outcomes in the rural high-altitude Andes of Peru
How a realistic magnetosphere alters the polarizations of surface, fast magnetosonic, and Alfvén waves
Funding: MOA holds a UKRI (STFC / EPSRC) Stephen Hawking Fellowship EP/T01735X/1. DJS was supported by STFC grant ST/S000364/1. MDH was supported by NASA grant 80NSSC19K0127. A.N.W. was partially funded by STFC grant ST/N000609/1.System-scale magnetohydrodynamic (MHD) waves within Earth?s magnetosphere are often understood theoretically using box models. While these have been highly instructive in understanding many fundamental features of the various wave modes present, they neglect the complexities of geospace such as the inhomogeneities and curvilinear geometries present. Here we show global MHD simulations of resonant waves impulsively-excited by a solar wind pressure pulse. Although many aspects of the surface, fast magnetosonic (cavity/waveguide), and Alfvén modes present agree with the box and axially symmetric dipole models, we find some predictions for large-scale waves are significantly altered in a realistic magnetosphere. The radial ordering of fast mode turning points and Alfvén resonant locations may be reversed even with monotonic wave speeds. Additional nodes along field lines that are not present in the displacement/velocity occur in both the perpendicular and compressional components of the magnetic field. Close to the magnetopause the perpendicular oscillations of the magnetic field have the opposite handedness to the velocity. Finally, widely-used detection techniques for standing waves, both across and along the field, can fail to identify their presence. We explain how all these features arise from the MHD equations when accounting for a non-uniform background field and propose modified methods which might be applied to spacecraft observations.Publisher PDFPeer reviewe
Improving household air, drinking water and hygiene in rural Peru : a community-randomized-controlled trial of an integrated environmental home-based intervention package to improve child health
Diarrhoea and acute lower respiratory infections are leading causes of childhood morbidity and mortality, which can be prevented by simple low-cost interventions. Integrated strategies can provide additional benefits by addressing multiple health burdens simultaneously.; We conducted a community-randomized-controlled trial in 51 rural communities in Peru to evaluate whether an environmental home-based intervention package, consisting of improved solid-fuel stoves, kitchen sinks, solar disinfection of drinking water and hygiene promotion, reduces lower respiratory infections, diarrhoeal disease and improves growth in children younger than 36 months. The attention control group received an early child stimulation programme.; We recorded 24Â 647 child-days of observation from 250 households in the intervention and 253 in the attention control group during 12-month follow-up. Mean diarrhoea incidence was 2.8 episodes per child-year in the intervention compared with 3.1 episodes in the control arm. This corresponds to a relative rate of 0.78 [95% confidence interval (CI): 0.58-1.05] for diarrhoea incidence and an odds ratio of 0.71 (95% CI: 0.47-1.06) for diarrhoea prevalence. No effects on acute lower respiratory infections or children's growth rates were observed.; Combined home-based environmental interventions slightly reduced childhood diarrhoea, but the confidence interval included unity. Effects on growth and respiratory outcomes were not observed, despite high user compliance of the interventions. The absent effect on respiratory health might be due to insufficient household air quality improvements of the improved stoves and additional time needed to achieve attitudinal and behaviour change when providing composite interventions
Polaronic excitations in CMR manganite films
In the colossal magnetoresistance manganites polarons have been proposed as
the charge carrier state which localizes across the metal-insulator transition.
The character of the polarons is still under debate. We present an assessment
of measurements which identify polarons in the metallic state of
La{2/3}Sr{1/3}MnO{3} (LSMO) and La{2/3}Ca{1/3}MnO{3} (LCMO) thin films. We
focus on optical spectroscopy in these films which displays a pronounced
resonance in the mid-infrared. The temperature dependent resonance has been
previously assigned to polaron excitations. These polaronic resonances are
qualitatively distinct in LSMO and LCMO and we discuss large and small polaron
scenarios which have been proposed so far. There is evidence for a large
polaron excitation in LSMO and small polarons in LCMO. These scenarios are
examined with respect to further experimental probes, specifically charge
carrier mobility (Hall-effect measurements) and high-temperature
dc-resistivity.Comment: 16 pages, 10 figure
Effects of loudness and complex speech on spataial and temporal precision in Parkinson's Disease
The paper presents preliminary results of a speech
motor control study of hypokinetic dysarthria in
Parkinson's disease (PD). By means of EPG, the
tongue contacts of two speakers with PD and two
control speakers during the production of target
words containing initial /t/ stops were analysed in
normal and loud condition as well as in complex
sentences. The preliminary results showed no
effects of increasing loudness on duration and on
the number of tongue contacts in speakers with
PD. Furthermore, frication of the stop /p/ to [f] was
found for one speaker in the acoustic analysis.casl[1] Alm, P. 2004. Stuttering and the basal ganglia circuits: A
critical review of possible relations. JCD 37, 325-369.
[2] Dromey, C. Ramig, L.O. 1998. Intentional changes in
sound pressure level and rate: Their impacts on measures
of respiration, phonation, and articulation. JSLHR 41,
1003-1018.
[3] Dromey, C. 2000. Articulatory kinematic in patients with
Parkinson disease using different speech treatment
approaches. Journal of Medical Speech-Language
Pathology 8, 155-161.
[4] Kent, R. D., Weismer, G., Kent, J. F., Rosenbek, J. C.
1989. Toward phonetic intelligibility testing in
dysarthria. JSHD 54, 482-99.
[5] Kleinow, J., Smith, A., Ramig, L.O. 2001. Speech motor
stability in idiopathic Parkinson's disease: effects of rate
and loudness manipulations. JSLHR 44, 1041-1051.
[6] McAuliffe, M. J., Ward, E.C., Murdoch, B.E. 2006.
Speech production in Parkinson's disease: I. An
electropalatographic investigation of tongue-palate
contact patterns. Clinical Linguistics and Phonetics 20, 1-
18.
[7] McAuliffe, M. J., Ward, E.C., Murdoch, B.E. 2006.
Speech production in Parkinson's disease: II. Acoustic
and electropalatographic investigation of sentence, word
and segment durations. Clinical Linguistics and
Phonetics 20, 19-33.
[8] Mooshammer, C., Hoole, P., Geumann, A. (in press). Jaw
and order. Language and Speech.
[9] Schulman, R. 1989. Articulatory dynamics of loud and
normal speech. J. Acoust. Soc. Am. 85, 295-312.
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Journal of Phonetics 17, 3-45.pub53pu
Simultaneous traveling convection vortex events and Pc1 wave bursts at cusp latitudes observed in Arctic Canada and Svalbard
Traveling convection vortices (TCVs), which appear in ground magnetometer records at nearâcusp latitudes as solitary ~5 mHz pulses, are a signature of dynamical processes in the ion foreshock upstream of the Earth's bow shock that can stimulate transient compressions of the dayside magnetosphere. These compressions can also increase the growth rate of electromagnetic ion cyclotron (EMIC) waves, which appear in ground records at these same latitudes as bursts of Pc1 pulsations. In this study we have identified TCVs and simultaneous Pc1 burst events in two regions, Eastern Arctic Canada and Svalbard, using a combination of fluxgate magnetometers and search coil magnetometers in each region. By looking for the presence of TCVs and Pc1 bursts in two different sequences, we have found that the distribution of Pc1 bursts was more tightly clustered near local noon than that of TCV events, that neither TCVs nor Pc1 bursts were always associated with the other, and even when they occurred simultaneously their amplitudes showed little correlation. Magnetometer data from GOESâ12 were also used to characterize the strength of the magnetic compressions at geosynchronous orbit near the magnetic equator. Compressions >â2 nT at GOESâ12 occurred during 57% of the Canadian TCV events, but during ~85% of the simultaneous TCV/Pc1 burst events. There was again little evident correlation between TCV and GOESâ12 compression amplitudes. We have also documented unusually low EMIC wave activity during this deep solar minimum interval, and we attribute the low occurrence percentage of combined events in this study to this minimum. Key Points TCVs and Pc1 bursts often occur together in highâlatitude magnetometer data Pc1 events were more tightly clustered near local noon than TCV events Pc1 activity was unusually low during the solar activity minimum in 2008â2010.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101826/1/jgra50604.pd
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