2,554 research outputs found
Cardiac evaluation of candidates for kidney transplantation: value of exercise radionuclide angiocardiography
In view of the high incidence and mortality of coronary artery disease (CAD) in patients with kidney transplantation, a systematic cardiac evaluation was prospectively performed in 103 uraemic patients eligible for transplantation. After clinical examination, 28 patients with symptoms of CAD or diabetes mellitus were referred directly for coronary angiography, whereas the remaining 75 patients had rest and exercise radionuclide angiocardiography for evaluation of possible asymptomatic CAD. Among them, left ventricular ejection fraction was below 40% at rest or fell during exercise by at least 5 EF% in 12 patients; coronary angiography in nine showed CAD in four and hypertensive heart disease in five. In the remaining 63 (of 75) patients without severe resting left ventricular dysfunction or exercise ischaemia, the follow-up of 28 ±7 months revealed no clinical manifestation of CAD. Overall incidence of CAD in symptomatic and asymptomatic patients during a follow-up of 27 months after cardiac evaluation was 20 and 25% in non-diabetic and diabetic candidates for kidney transplantation, respectively (P = n.s.). Thus, clinical examination combined with exercise radionuclide angiocardiography in patients without signs or symptoms of heart disease had a high predictive accuracy for presence or absence of late manifestations of CAD. Exercise radionuclide angiocardiography is therefore a useful method for screening kidney transplantation candidates for asymptomatic CA
A First Look at Rotation in Inactive Late-Type M Dwarfs
We have examined the relationship between rotation and activity in 14
late-type (M6-M7) M dwarfs, using high resolution spectra taken at the W.M.
Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey.
Most were selected to be inactive at a spectral type where strong H-alpha
emission is quite common. We used the cross-correlation technique to quantify
the rotational broadening; six of the stars in our sample have vsini > 3.5
km/s. Our most significant and perplexing result is that three of these stars
do not exhibit H-alpha emission, despite rotating at velocities where previous
work has observed strong levels of magnetic field and stellar activity. Our
results suggest that rotation and activity in late-type M dwarfs may not always
be linked, and open several additional possibilities including a
rotationally-dependent activity threshold, or a possible dependence on stellar
parameters of the Rossby number at which magnetic/activity "saturation" takes
place in fully convective stars.Comment: 8 pages, 4 figures, accepted for publication in Ap
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Cross-Sectional Associations of 24-Hour Sedentary Time, Physical Activity, and Sleep Duration Compositions with Sleep Quality and Habits in Preschoolers
Although some studies indicate physical activity and sleep quality are positively associated in children, most reports examined physical activity independent of other 24-h behaviors and focused on older children. The aim of this cross-sectional study was to examine the predicted changes in sleep efficiency and habits when reallocating time between movement behaviors using compositional isotemporal substitution in preschool-aged children. Accelerometers were worn by 288 participants (51.6 ± 9.5 months) for up to 16 days. Sleep outcomes included sleep efficiency, nap frequency, sleep disturbances, and bedtime resistance. Compositional isotemporal substitution analyses demonstrated that the combined effect of 24-h movement behaviors was associated with sleep efficiency (p \u3c 0.001) and nap frequency (p \u3c 0.003). When sleep increased by 30 min at the expense of stationary time or light physical activity, estimates of sleep efficiency and bedtime resistance decreased while nap frequency increased. When stationary time increased by 30 min from moderate to vigorous physical activity, estimated sleep efficiency increased and sleep disturbances decreased. Although this study presents preliminary evidence that 24-h movement behavior compositions in early childhood are associated with sleep quality and nap frequency, estimated effects from theoretical time reallocations across sleep outcomes were mixed
Towards a Notion of Distributed Time for Petri Nets
We set the ground for research on a timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. The novelty is that, rather than a single global clock, we use a set of unrelated clocks --- possibly one per place --- allowing a local timing as well as distributed time synchronisation. We give a formal definition of the model and investigate properties of local versus global timing, including decidability issues and notions of processes of the respective models
A convergent interaction engine: vocal communication among marmoset monkeys
To understand the primate origins of the human interaction engine, it is worthwhile to focus not only on great apes but also on callitrichid monkeys (marmosets and tamarins). Like humans, but unlike great apes, callitrichids are cooperative breeders, and thus habitually engage in coordinated joint actions, for instance when an infant is handed over from one group member to another. We first explore the hypothesis that these habitual cooperative interactions, the marmoset interactional ethology, are supported by the same key elements as found in the human interaction engine: mutual gaze (during joint action), turn-taking, volubility, as well as group-wide prosociality and trust. Marmosets show clear evidence of these features. We next examine the prediction that, if such an interaction engine can indeed give rise to more flexible communication, callitrichids may also possess elaborate communicative skills. A review of marmoset vocal communication confirms unusual abilities in these small primates: high volubility and large vocal repertoires, vocal learning and babbling in immatures, and voluntary usage and control. We end by discussing how the adoption of cooperative breeding during human evolution may have catalysed language evolution by adding these convergent consequences to the great ape-like cognitive system of our hominin ancestors.
This article is part of the theme issue ‘Revisiting the human ‘interaction engine’: comparative approaches to social action coordination’
The impact of a randomized controlled trial of a lifestyle intervention on postpartum physical activity among at-risk hispanic women: Estudio PARTO
AIMS: To assess the impact of a culturally modified, motivationally targeted, individually-tailored intervention on postpartum physical activity (PA) and PA self-efficacy among Hispanic women.
METHODS: Estudio PARTO was a randomized controlled trial conducted in Western Massachusetts from 2013-17. Hispanic women who screened positive for gestational diabetes mellitus were randomized to a Lifestyle Intervention (LI, n = 100) or to a comparison Health and Wellness (HW, n = 104) group during late pregnancy. Exercise goals in LI were to meet American College of Obstetrician and Gynecologists guidelines for postpartum PA. The Pregnancy Physical Activity Questionnaire (PPAQ) and the Self-Efficacy for Physical Activity Questionnaire were administered at 6 weeks, 6 months, and 1 year postpartum.
RESULTS: Compared to baseline levels, both groups had significant increases in moderate-to-vigorous PA at 6 months and one year postpartum (i.e., LI: mean change = 30.9 MET-hrs/wk, p = 0.05; HW: 27.6 MET-hrs/wk, p = 0.01), with only LI group experiencing significant increases in vigorous PA (mean change = 1.3 MET-hrs/wk, p = 0.03). Based on an intent-to-treat analysis using mixed effects models, we observed no differences in pattern of change in PA intensity and type over time between intervention groups (all p \u3e 0.10). However, there was the suggestion of a greater decrease in sedentary activity in the LI group compared to the HW group (beta = -3.56, p = 0.09).
CONCLUSIONS: In this randomized trial among high-risk Hispanic women, both groups benefitted from participation in a postpartum intervention
Effectiveness, safety and tolerability of a complex homeopathic medicinal product in the prevention of recurrent acute upper respiratory tract infections in children: a multicenter, open, comparative, randomized, controlled clinical trial
Background: The present study was initiated to investigate the effectiveness, safety and tolerability of complex homeopathic CalSuli-4-02 tablets on prevention of recurrent acute upper respiratory tract infections (URTIs) in children, in comparison to another complex homeopathic product. Methods: The study was designed as a prospective, multicenter, randomized, open, clinical trial with two parallel treatment groups at four outpatient pediatric clinics in Russia. Children aged <= 6 years with susceptibility to acute URTIs (>= three occasions during the last 6 months) were randomized to receive either CalSuli-4-02 or a comparator homeopathic product (control group) for 3 weeks. Primary outcome was the frequency of acute URTIs after 3 and 6 months post-treatment follow-up. Secondary endpoints were changes in complaints and symptoms (total and individual scores), treatment satisfaction, antibiotic use, safety and tolerability. Results: The intention-to-treat analysis involved 200 children (CalSuli-4-02: N = 99, Control: N = 101). In both treatment groups, the median number of acute URTIs was one for 3 months and two, respectively, for the full 6 months post-treatment (Relative Risk: 0.86 (95 %-CI: 0.72-1.03), p = 0.1099). Seasons had no influence on the outcome. At the end of study, CalSuli-4-02 had overall higher odds of getting lower complaints severity total score (Odds ratio: 1.99 (95 %-CI: 1.31-3.02), p = 0.0012) and showing symptom improvement (Odds ratio: 1.93 (95 %-CI: 1.25-3.00), p = 0.0033). Specifically, the complaint "appetite disorder" and the symptom "child's activities" significantly improved more in the CalSuli-4-02 group (p = 0.0135 and p = 0.0063, respectively). Antibiotic use was decreased in both treatment groups at the study end. Overall assessment for satisfaction with and tolerability of treatment was higher with CalSuli-4-02. A low number of non-serious adverse drug reactions was reported (CalSuli-4-02: N = 4, Control: N = 1). Conclusions: Both complex homeopathic products led to a comparable reduction of URTIs. In the CalSuli-4-02 group, significantly less URTI-related complaints and symptoms and higher treatment satisfaction and tolerability were detected. The observation that the use of antibiotics was reduced upon treatment with the complex homeopathic medications, without the occurrence of complications, is interesting and warrants further investigations on the potential of CalSuli-4-02 as an antibiotic sparing option
The Longitudinal Polarimeter at HERA
The design, construction and operation of a Compton back-scattering laser
polarimeter at the HERA storage ring at DESY are described. The device measures
the longitudinal polarization of the electron beam between the spin rotators at
the HERMES experiment with a fractional systematic uncertainty of 1.6%. A
measurement of the beam polarization to an absolute statistical precision of
0.01 requires typically one minute when the device is operated in the
multi-photon mode. The polarimeter also measures the polarization of each
individual electron bunch to an absolute statistical precision of 0.06 in
approximately five minutes. It was found that colliding and non-colliding
bunches can have substantially different polarizations. This information is
important to the collider experiments H1 and ZEUS for their future
longitudinally polarized electron program because those experiments use the
colliding bunches only.Comment: 21 pages (Latex), 14 figures (EPS
High affinity binding of hydrophobic and autoantigenic regions of proinsulin to the 70 kDa chaperone DnaK
BACKGROUND: Chaperones facilitate proper folding of peptides and bind to misfolded proteins as occurring during periods of cell stress. Complexes of peptides with chaperones induce peptide-directed immunity. Here we analyzed the interaction of (pre)proinsulin with the best characterized chaperone of the hsp70 family, bacterial DnaK.
RESULTS: Of a set of overlapping 13-mer peptides of human preproinsulin high affinity binding to DnaK was found for the signal peptide and one further region in each proinsulin domain (A- and B-chain, C-peptide). Among the latter, peptides covering most of the B-chain region B11-23 exhibited strongest binding, which was in the range of known high-affinity DnaK ligands, dissociation equilibrium constant (K'd) of 2.2 ± 0.4 μM. The B-chain region B11-23 is located at the interface between two insulin molecules and not accessible in insulin oligomers. Indeed, native insulin oligomers showed very low DnaK affinity (K'd 67.8 ± 20.8 μM) whereas a proinsulin molecule modified to prevent oligomerization showed good binding affinity (K'd 11.3 ± 7.8 μM).
CONCLUSIONS: Intact insulin only weakly interacts with the hsp70 chaperone DnaK whereas monomeric proinsulin and peptides from 3 distinct proinsulin regions show substantial chaperone binding. Strongest binding was seen for the B-chain peptide B 11-23. Interestingly, peptide B11-23 represents a dominant autoantigen in type 1 diabetes
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