239 research outputs found
Oxygen Uptake, Ventilation, and Symptoms During Low-Frequency Versus High-Frequency NMES in COPD: A Pilot Study.
Problematic Activities of Daily Life are Weakly Associated With Clinical Characteristics in COPD
BACKGROUND: Problematic activities of daily life (ADLs) can be the main reason to refer patients with chronic obstructive pulmonary disease (COPD) for pulmonary rehabilitation. To date, information on problematic ADLs and their clinical correlates in COPD remain scarce. This retrospective chart review aimed to identify the most prevalent self-reported problematic ADLs in COPD patients, determine performance and satisfaction scores of these problematic ADLs, and explore the association between 13 clinical determinants and 4 problematic ADL domains. METHODS: A total of 820 COPD patients entering pulmonary rehabilitation assessment were included in this retrospective study. Self-reported problematic ADLs were assessed using the Canadian Occupational Performance Measure, administered by occupational therapists in the form of a semistructured interview. RESULTS: COPD patients (59% male, age 63.6 +/- 9.3 years, FEV1 (%pred): 46.4 +/- 18.4) reported 2999 problematic ADLs. The most prevalent problematic ADLs were walking (68%), stair climbing (35%), and cycling (30%). Moreover, 30% of the patients reported "not able to do any of the scored problematic ADL" and 44% were "not satisfied at all with the performance of any of the scored problematic ADL." Significant but weak associations were found between clinical determinants (eg, physical and psychosocial) and problematic ADLs. CONCLUSIONS: The lack of a strong association between problematic ADLs and clinical determinants emphasizes the need for individualized assessment of these ADLs to allow tailored intervention
Mobile Phone-Delivered Cognitive Behavioral Therapy for Insomnia:A Randomized Waitlist Controlled Trial
Background: This study is one of the first randomized controlled trials investigating cognitive behavioral therapy for insomnia (CBT-I) delivered by a fully automated mobile phone app. Such an app can potentially increase the accessibility of insomnia treatment for the 10% of people who have insomnia. Objective: The objective of our study was to investigate the efficacy of CBT-I delivered via the Sleepcare mobile phone app, compared with a waitlist control group, in a randomized controlled trial. Methods: We recruited participants in the Netherlands with relatively mild insomnia disorder. After answering an online pretest questionnaire, they were randomly assigned to the app (n=74) or the waitlist condition (n=77). The app packaged a sleep diary, a relaxation exercise, sleep restriction exercise, and sleep hygiene and education. The app was fully automated and adjusted itself to a participant’s progress. Program duration was 6 to 7 weeks, after which participants received posttest measurements and a 3-month follow-up. The participants in the waitlist condition received the app after they completed the posttest questionnaire. The measurements consisted of questionnaires and 7-day online diaries. The questionnaires measured insomnia severity, dysfunctional beliefs about sleep, and anxiety and depression symptoms. The diary measured sleep variables such as sleep efficiency. We performed multilevel analyses to study the interaction effects between time and condition. Results: The results showed significant interaction effects (P<.01) favoring the app condition on the primary outcome measures of insomnia severity (d=–0.66) and sleep efficiency (d=0.71). Overall, these improvements were also retained in a 3-month follow-up. Conclusions: This study demonstrated the efficacy of a fully automated mobile phone app in the treatment of relatively mild insomnia. The effects were in the range of what is found for Web-based treatment in general. This supports the applicability of such technical tools in the treatment of insomnia. Future work should examine the generalizability to a more diverse population. Furthermore, the separate components of such an app should be investigated. It remains to be seen how this app can best be integrated into the current health regimens. Trial Registration: Netherlands Trial Register: NTR5560; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5560 (Archived by WebCite at http://www.webcitation.org/6noLaUdJ4
Characteristics and determinants of endurance cycle ergometry and six-minute walk distance in patients with COPD
BACKGROUND: Exercise tolerance can be assessed by the cycle endurance test (CET) and six-minute walk test (6MWT) in patients with Chronic Obstructive Pulmonary Disease (COPD). We sought to investigate the characteristics of functional exercise performance and determinants of the CET and 6MWT in a large clinical cohort of COPD patients. METHODS: A dataset of 2053 COPD patients (43% female, age: 66.9 ± 9.5 years, FEV(1)% predicted: 48.2 ± 23.2) was analyzed retrospectively. Patients underwent, amongst others, respiratory function evaluation; medical tests and questionnaires, one maximal incremental cycle test where peak work rate was determined and two functional exercise tests: a CET at 75% of peak work rate and 6MWT. A stepwise multiple linear regression was used to assess determinants. RESULTS: On average, patients had impaired exercise tolerance (peak work rate: 56 ± 27% predicted, 6MWT: 69 ± 17% predicted). A total of 2002 patients had CET time of duration (CET-T(end)) less than 20 min while only 51 (2.5%) of the patients achieved 20 min of CET-T(end) . In former patients, the percent of predicted peak work rate achieved differed significantly between men (48 ± 21% predicted) and women (67 ± 31% predicted). In contrast, CET-T(end) was longer in men (286 ± 174 s vs 250 ± 153 s, p < 0.001). Also, six minute walking distance (6MWD) was higher in men compared to women, both in absolute terms as in percent of predicted (443 m, 67%predicted vs 431 m, 72%predicted, p < 0.05). Gender was associated with the CET-T(end) but BMI, FEV(1) and FRC were related to the 6MWD highlighting the different determinants of exercise performance between CET and 6MWT. CONCLUSIONS: CET-T(end) is a valuable outcome of CET as it is related to multiple clinical aspects of disease severity in COPD. Gender difference should temper the interpretation of CET
What we do and do not know about the s-process
AGB stars are the source for the main component of the -process. Here we
discuss both the properties which are reasonably well known and those which
still suffer from substantial uncertainties. In the former case, we are fairly
sure that the -process contribution from AGB stars comes from masses between
about 1 and 3 \msun, and the dominant neutron source is the
C,n)O reaction. In the latter category remains the
formation mechanism for the C-pocket. Attempts at including rotation
seem to inhibit neutron capture reactions. Explaining the observations seems to
require a spread in the size of the C-pocket so some stochastic process,
such as rotation, must be involved.Comment: To be published in Nuclear Physics A; Invited Review for "Nuclei in
the Cosmos VIII", Vancouver, July 200
Gravitational waves from rapidly rotating neutron stars
Rapidly rotating neutron stars in Low Mass X-ray Binaries have been proposed
as an interesting source of gravitational waves. In this chapter we present
estimates of the gravitational wave emission for various scenarios, given the
(electromagnetically) observed characteristics of these systems. First of all
we focus on the r-mode instability and show that a 'minimal' neutron star model
(which does not incorporate exotica in the core, dynamically important magnetic
fields or superfluid degrees of freedom), is not consistent with observations.
We then present estimates of both thermally induced and magnetically sustained
mountains in the crust. In general magnetic mountains are likely to be
detectable only if the buried magnetic field of the star is of the order of
G. In the thermal mountain case we find that gravitational
wave emission from persistent systems may be detected by ground based
interferometers. Finally we re-asses the idea that gravitational wave emission
may be balancing the accretion torque in these systems, and show that in most
cases the disc/magnetosphere interaction can account for the observed spin
periods.Comment: To appear in 'Gravitational Waves Astrophysics: 3rd Session of the
Sant Cugat Forum on Astrophysics, 2014', Editor: Carlos F. Sopuert
Are the magnetic fields of millisecond pulsars ~ 10^8 G?
It is generally assumed that the magnetic fields of millisecond pulsars
(MSPs) are G. We argue that this may not be true and the fields
may be appreciably greater. We present six evidences for this: (1) The G field estimate is based on magnetic dipole emission losses which is
shown to be questionable; (2) The MSPs in low mass X-ray binaries (LMXBs) are
claimed to have G on the basis of a Rayleygh-Taylor instability
accretion argument. We show that the accretion argument is questionable and the
upper limit G may be much higher; (3) Low magnetic field neutron
stars have difficulty being produced in LMXBs; (4) MSPs may still be accreting
indicating a much higher magnetic field; (5) The data that predict G for MSPs also predict ages on the order of, and greater than, ten
billion years, which is much greater than normal pulsars. If the predicted ages
are wrong, most likely the predicted G fields of MSPs are wrong;
(6) When magnetic fields are measured directly with cyclotron lines in X-ray
binaries, fields G are indicated. Other scenarios should be
investigated. One such scenario is the following. Over 85% of MSPs are
confirmed members of a binary. It is possible that all MSPs are in large
separation binaries having magnetic fields G with their magnetic
dipole emission being balanced by low level accretion from their companions.Comment: 16 pages, accept for publication in Astrophysics and Space Scienc
Low-Luminosity Accretion in Black Hole X-ray Binaries and Active Galactic Nuclei
At luminosities below a few percent of Eddington, accreting black holes
switch to a hard spectral state which is very different from the soft
blackbody-like spectral state that is found at higher luminosities. The hard
state is well-described by a two-temperature, optically thin, geometrically
thick, advection-dominated accretion flow (ADAF) in which the ions are
extremely hot (up to K near the black hole), the electrons are also
hot ( K), and thermal Comptonization dominates the X-ray
emission. The radiative efficiency of an ADAF decreases rapidly with decreasing
mass accretion rate, becoming extremely low when a source reaches quiescence.
ADAFs are expected to have strong outflows, which may explain why relativistic
jets are often inferred from the radio emission of these sources. It has been
suggested that most of the X-ray emission also comes from a jet, but this is
less well established.Comment: To appear in "From X-ray Binaries to Quasars: Black Hole Accretion on
All Mass Scales" edited by T. Maccarone, R. Fender, L. Ho, to be published as
a special edition of "Astrophysics and Space Science" by Kluwe
Prescribing and adjusting exercise training in chronic respiratory diseases – Expert-based practical recommendations
Background
International guidelines recommend endurance (ET) and strength training (ST) in patients with chronic respiratory diseases (CRDs), but only provide rough guidance on how to set the initial training load. This may unintentionally lead to practice variation and inadequate training load adjustments. This study aimed to develop practical recommendations on tailoring ET and ST based on practices from international experts from the field of exercise training in CRDs.
Methods
35 experts were invited to address a 64-item online survey about how they prescribe and adjust exercise training.
Results
Cycling (97%) and walking (86%) were the most commonly implemented ET modalities. Continuous endurance training (CET, 83%) and interval endurance training (IET, 86%) were the frequently applied ET types. Criteria to prescribe IET instead of CET were: patients do not tolerate CET due to dyspnoea at the initial training session (79%), intense breathlessness during initial exercise assessment (76%), and/or profound exercise-induced oxygen desaturation (59%). For ST, most experts (68%) recommend 3 sets per exercise; 62% of experts set the intensity at a specific load that patients can tolerate for a range of 8 to 15 repetitions per set. Also, 56% of experts advise patients to approach local muscular exhaustion at the end of a single ST set.
Conclusions
The experts´ practices were summarized to develop practical recommendations in the form of flowcharts on how experts apply and adjust CET, IET, and ST in patients with CRDs. These recommendations may guide health care professionals to optimize exercise training programs in patients with CRDs
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