247 research outputs found
Aging and Infectious Diseases in the Developing World
Although demographic aging does not remain restricted to industrialized countries, the medical challenge arising from the aging population will be distinct in the developing world. This is particularly true with respect to infectious diseases, which have a distinct spectrum in the elderly population, as well as a greater overall relevance in the developing world. Tropical diseases have a specific presentation and epidemiology in elderly patients. Infectious diseases with a worldwide distribution impact elderly patients in the developing world in a specific manner, which is most obvious with respect to human immunodeficiency virus and tuberculosis but is also true with respect to "trivial” manifestations of infection, such as diarrhea and pneumonia. Malnutrition contributes in a major way to the immunodeficiency of elderly patients in the developing world. Poorly controlled use of antimicrobial drugs leads to multidrug-resistant microorganisms, which, together with the limited resources available for drug treatment, makes appropriate treatment of infections in elderly patients in developing countries very difficult. Infections in elderly patients will have an increasing impact on the public health and economy of developing countrie
Effect of music-based multitask training on cognition and mood in older adults
Background: in a secondary analysis of a randomised controlled trial, we investigated whether 6 months of music-based multitask training had beneficial effects on cognitive functioning and mood in older adults. Methods: 134 community-dwellers aged ≥65 years at increased risk for falling were randomly assigned to either an intervention group (n = 66) who attended once weekly 1-h supervised group classes of multitask exercises, executed to the rhythm of piano music, or a control group with delayed intervention (n = 68) who maintained usual lifestyle habits, for 6 months. A short neuropsychological test battery was administered by an intervention-blinded neuropsychologist at baseline and Month 6, including the mini-mental state examination (MMSE), the clock-drawing test, the frontal assessment battery (FAB) and the hospital anxiety (HADS-A) and depression scale. Results: intention-to-treat analysis showed an improvement in the sensitivity to interference subtest of the FAB (adjusted between-group mean difference (AMD), 0.12; 95% CI, 0.00 to 0.25; P = 0.047) and a reduction in anxiety level (HADS-A; AMD, −0.88; 95% CI, −1.73 to −0.05; P = 0.039) in intervention participants, as compared with the controls. Within-group analysis revealed an increase in MMSE score (P = 0.004) and a reduction in the number of participants with impaired global cognitive performance (i.e., MMSE score ≤23; P = 0.003) with intervention. Conclusion: six months of once weekly music-based multitask training was associated with improved cognitive function and decreased anxiety in community-dwelling older adults, compared with non-exercising controls. Studies designed to further delineate whether training-induced changes in cognitive function could contribute to dual-task gait improvements and falls reduction, remain to be conducte
DNA- and RNA- Derived Fungal Communities in Subsurface Aquifers Only Partly Overlap but React Similarly to Environmental Factors
Recent advances in high-throughput sequencing (HTS) technologies have revolutionized
our understanding of microbial diversity and composition in relation to their environment. HTS-based
characterization of metabolically active (RNA-derived) and total (DNA-derived) fungal communities
in different terrestrial habitats has revealed profound differences in both richness and community
compositions. However, such DNA- and RNA-based HTS comparisons are widely missing for
fungal communities of groundwater aquifers in the terrestrial biogeosphere. Therefore, in this
study, we extracted DNA and RNA from groundwater samples of two pristine aquifers in the
Hainich CZE and employed paired-end Illumina sequencing of the fungal nuclear ribosomal internal
transcribed spacer 2 (ITS2) region to comprehensively test difference/similarities in the “total” and
“active” fungal communities. We found no significant differences in the species richness between
the DNA- and RNA-derived fungal communities, but the relative abundances of various fungal
operational taxonomic units (OTUs) appeared to differ. We also found the same set of environmental
parameters to shape the “total” and “active” fungal communities in the targeted aquifers. Furthermore,
our comparison also underlined that about 30%–40% of the fungal OTUs were only detected in
RNA-derived communities. This implies that the active fungal communities analyzed by HTS
methods in the subsurface aquifers are actually not a subset of supposedly total fungal communities.
In general, our study highlights the importance of differentiating the potential (DNA-derived) and
expressed (RNA-derived) members of the fungal communities in aquatic ecosystems
Dual-task related gait changes after CSF tapping: a new way to identify idiopathic normal pressure hydrocephalus
BACKGROUND: Gait disturbances found in patients with idiopathic normal pressure hydrocephalus (iNPH) are unspecific to the diagnosis and commonly occur in neurodegenerative or vascular conditions (iNPH-like conditions). This current retrospective pre-post intervention study aims to determine whether changes in quantitative gait parameters during dual task condition differed between iNPH and iNPH-like conditions before and after cerebrospinal fluid (CSF) tapping. METHODS: 49 patients assessed before and after CSF tapping were included in this study (27 with iNPH and 22 with iNPH-like conditions). Gait analysis during single and dual task conditions (walking and backward counting) was performed before and after a CSF spinal tap of 40 ml. Gait parameters were compared between iNPH and iNPH-like conditions patients. Logistic regressions were used to examine the association between iNPH and gait parameters. RESULTS: Improvements of step width (−9.03 (20.75)% for iNPH group; +0.28 (21.76)% for iNPH-like conditions group), stride length (+7.82 (20.71)% for iNPH group; -0.62 (19.22)% for iNPH-like conditions group), walking speed (+12.20 (29.79)% for iNPH group; +2.38 (32.50)% for iNPH-like conditions group) and stance duration (−1.23 (4.03)% for iNPH group; +0.49 (5.12)% for iNPH-like conditions group) during dual task, after CSF spinal tapping, were significant in patients with iNPH compared to patients with iNPH-like conditions. No between group difference was observed for the single walking task evaluation. The multiple logistic regression revealed that among these four gait parameters, only the improvement in step width was associated with the diagnosis of iNPH. CONCLUSION: Dual-task related changes in spatio-temporal gait parameters before and after CSF tapping might be a novel and discriminative method of identifying iNPH patients from other similar conditions
Test-retest reliability of stride time variability while dual tasking in healthy and demented adults with frontotemporal degeneration
Although test-retest reliability of mean values of spatio-temporal gait parameters has been assessed for reliability while walking alone (i.e., single tasking), little is known about the test-retest reliability of stride time variability (STV) while performing an attention demanding-task (i.e., dual tasking). The objective of this study was to examine immediate test-retest reliability of STV while single and dual tasking in cognitively healthy older individuals (CHI) and in demented patients with frontotemporal degeneration (FTD)
Calibration of Drive Non-Linearity for Arbitrary-Angle Single-Qubit Gates Using Error Amplification
The ability to execute high-fidelity operations is crucial to scaling up
quantum devices to large numbers of qubits. However, signal distortions
originating from non-linear components in the control lines can limit the
performance of single-qubit gates. In this work, we use a measurement based on
error amplification to characterize and correct the small single-qubit rotation
errors originating from the non-linear scaling of the qubit drive rate with the
amplitude of the programmed pulse. With our hardware, and for a 15-ns pulse,
the rotation angles deviate by up to several degrees from a linear model. Using
purity benchmarking, we find that control errors reach , which
accounts for half of the total gate error. Using cross-entropy benchmarking, we
demonstrate arbitrary-angle single-qubit gates with coherence-limited errors of
and leakage below . While the exact
magnitude of these errors is specific to our setup, the presented method is
applicable to any source of non-linearity. Our work shows that the
non-linearity of qubit drive line components imposes a limit on the fidelity of
single-qubit gates, independent of improvements in coherence times, circuit
design, or leakage mitigation when not corrected for
Current vortices in aromatic carbon molecules
The local current flow through three small aromatic carbon molecules, namely
benzene, naphthalene and anthracene, is studied. Applying density functional
theory and the non-equilibrium Green's function method for transport, we
demonstrate that pronounced current vortices exist at certain electron energies
for these molecules. The intensity of these circular currents, which appear not
only at the anti-resonances of the transmission but also in vicinity of its
maxima, can exceed the total current flowing through the molecular junction and
generate considerable magnetic fields. The electron system of the
molecular junctions is emulated experimentally by a network of macroscopic
microwave resonators. The local current flows in these experiments confirm the
existence of current vortices as a robust property of ring structures. The
circular currents can be understood in terms of a simple nearest-neighbor
tight-binding H\"uckel model. Current vortices are caused by the interplay of
the complex eigenstates of the open system which have energies close-by the
considered electron energy. Degeneracies, as observed in benzene and
anthracene, can thus generate strong circular currents, but also non-degenerate
systems like naphthalene exhibit current vortices. Small imperfections and
perturbations can couple otherwise uncoupled states and induce circular
currents
Structural Correlates of Personality Dimensions in Healthy Aging and MCI
The revised NEO Personality Inventory (NEOPI-R), popularly known as the five-factor model, defines five personality factors: Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness. The structural correlates of these personality factors are still a matter of debate. In this work, we examine the impact of subtle cognitive deficits on structural substrates of personality in the elderly using DTI derived white matter (WM) integrity measure, Fractional Anisotropy (FA). We employed canonical correlation analysis (CCA) to study the relationship between personality factors of the NEOPI-R and FA measures in two population groups: healthy controls and MCI. Agreeableness was the only personality factor to be associated with FA patterns in both groups. Openness was significantly related to FA data in the MCI group and the inverse was true for Conscientiousness. Furthermore, we generated saliency maps using bootstrapping strategy which revealed a larger number of positive correlations in healthy aging in contrast to the MCI status. The MCI group was found to be associated with a predominance of negative correlations indicating that higher Agreeableness and Openness scores were mostly related to lower FA values in interhemispheric and cortico-spinal tracts and a limited number of higher FA values in cortico-cortical and cortico-subcortical connection. Altogether these findings support the idea that WM microstructure may represent a valid correlate of personality dimensions and also indicate that the presence of early cognitive deficits led to substantial changes in the associations between WM integrity and personality factors
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