228,234 research outputs found
DouweHorsthuis/N-back-task-experiment: N-Back Experiment 3 versions
No full textThis repository has N-back experiments that run in Presentation® by NeuroBehavioral Systems. There are 3 versions:
Auditory Verbal (stimuli are letters that are spoken)
Visual Verbal (stimuli are letters that are written)
Visual Non-Verbal (stimuli are cubes shown at different locations)
The paradigm contains eyetracking code and presentation code. The whole experiment is explained in the readme file and the same counts for the timing setup of the paradigm
UK back pain exercise and manipulation (UK BEAM) trial - national randomised trial of physical treatments for back pain in primary care: objectives, design and interventions
No full textLow back pain has major health and social implications. Although there have been
many randomised controlled trials of manipulation and exercise for the management of low back
pain, the role of these two treatments in its routine management remains unclear. A previous trial
comparing private chiropractic treatment with National Health Service (NHS) outpatient
treatment, which found a benefit from chiropractic treatment, has been criticised because it did not
take treatment location into account. There are data to suggest that general exercise programmes
may have beneficial effects on low back pain. The UK Medical Research Council (MRC) has funded
this major trial of physical treatments for back pain, based in primary care. It aims to establish if,
when added to best care in general practice, a defined package of spinal manipulation and a defined
programme of exercise classes (Back to Fitness) improve participant-assessed outcomes.
Additionally the trial compares outcomes between participants receiving the spinal manipulation in
NHS premises and in private premises
Iceberg from Sir George Back's scrapbook, Eliza Pilleum [picture] /
No full textIn portfolio: Original watercolours Lt. F.W. Beechey (Capt. Parry's Expedition, 1819).; Rex Nan Kivell Collection NK3701/N.; Title from inscription below image.; T962
The Generalizability of Dual N-Back Training in Younger Adults
No full textIntroduction: The popularity of cognitive training has increased in recent years. Accumulating evidence shows that training can sometimes improve trained and non-trained cognitive functions, and these improvements may be related to individual differences in initial capacity and performance on the training task. The current study assessed the effectiveness of a custom-designed n-back task (the N-IGMA) versus an active control task (Blockmaster) at improving various forms of working memory capacity, attention, and fluid intelligence. Three measures of working memory capacity were considered: verbal, visuospatial and observed action. Methods: Outcome measures were assessed pre- and post-training. Nineteen healthy young adults (19-30 years of age) trained at-home for 30 minutes per day, five days a week for three weeks with either the N-IGMA (n=9) or Blockmaster n=10) at-home games. Results: Pre-post changes were observed for some outcome measures and these were equal for the N-IGMA and active control group. Outcome improvements could be due to simple test/re-test benefits or alternatively the N-IGMA and Blockmaster tasks may produce equivalent training effects. Improvements in the training tasks did not correlate with the changes in the outcome measures, suggesting improvements in the outcome measures might not be attributable to transfer of learning. For verbal working memory only, participants with higher (versus lower) initial fluid intelligence demonstrated larger improvements on the outcome measures suggesting that in future research training tasks might need to be tailored to the individual participant. Pre-assessment but not change scores were related for observed action and visuospatial working memory, consistent with some overlap between content domains. Conclusion: Despite specifically targeting working memory, the N-IGMA was not better than a visuospatial control game at improving a variety of cognitive outcome measures in this small sample. Results suggest that the individual’s initial cognitive capacity might need to be considered in future training studies. Caution should be used in extrapolating the results of this study to other populations of interest (e.g., older adults or individuals with cognitive deficits) since the present investigation included relatively high functioning individuals
N-Heterocyclic Carbene−Transition Metal Complexes: Spectroscopic and Crystallographic Analyses of π-Back-bonding Interactions
No full textThe ability of N-heterocyclic carbenes (NHCs) to participate in π-back-bonding interactions was
evaluated in a range of transition metal complexes. Rh chloride complexes containing a systematic series
of various 1,3-dimethyl-4,5-disubstituted-imidazol-2-ylidenes and either 1,5-cyclooctadiene (cod) or two
carbon monoxide ligands were synthesized (i.e., (NHC)RhCl(cod) and (NHC)RhCl(CO)2, respectively)
and studied using 1H NMR and IR spectroscopies. In the former series, the 1H NMR chemical shifts of
the signals attributable to the olefin trans to the NHC ligand were found to shift downfield by up to 0.17
ppm as the π-acidity of the substituents on the 4,5-positions increased (i.e., H → Cl → CN). Similarly,
in the latter series, the IR stretching frequencies of the carbonyl groups trans to the NHC ligands were
found to increase by 11 ± 0.5 cm-1 as π-acidity increased over the same series. Using the nitrile group
as a diagnostic handle, the CN stretching frequency of (1,3-dimethyl-4,5-dicyanoimidazol-2-ylidene)(cod)RhCl was found to be 4 ± 0.5 cm-1 higher than 1,3-dimethyl-4,5-dicyanoimidazol-2-ylidene)(CO)2RhCl, a more π-acidic analogue. X-ray analysis of the aforementioned series of (NHC)(cod)RhCl
complexes indicated changes in N−Ccarbene bond lengths that were consistent with greater π-donation
from complexes containing 4,5-dihydroimidazol-2-ylidene relative to the their 4,5-dicyano analogues.
Collectively, these results suggest not only that imidazol-2-ylidenes are capable of π-back-bonding but
that this interaction may be tuned by changing the π-acidity of the substituents on the imidazole ring
N-Heterocyclic Carbene−Transition Metal Complexes: Spectroscopic and Crystallographic Analyses of π-Back-bonding Interactions
No full textThe ability of N-heterocyclic carbenes (NHCs) to participate in π-back-bonding interactions was
evaluated in a range of transition metal complexes. Rh chloride complexes containing a systematic series
of various 1,3-dimethyl-4,5-disubstituted-imidazol-2-ylidenes and either 1,5-cyclooctadiene (cod) or two
carbon monoxide ligands were synthesized (i.e., (NHC)RhCl(cod) and (NHC)RhCl(CO)2, respectively)
and studied using 1H NMR and IR spectroscopies. In the former series, the 1H NMR chemical shifts of
the signals attributable to the olefin trans to the NHC ligand were found to shift downfield by up to 0.17
ppm as the π-acidity of the substituents on the 4,5-positions increased (i.e., H → Cl → CN). Similarly,
in the latter series, the IR stretching frequencies of the carbonyl groups trans to the NHC ligands were
found to increase by 11 ± 0.5 cm-1 as π-acidity increased over the same series. Using the nitrile group
as a diagnostic handle, the CN stretching frequency of (1,3-dimethyl-4,5-dicyanoimidazol-2-ylidene)(cod)RhCl was found to be 4 ± 0.5 cm-1 higher than 1,3-dimethyl-4,5-dicyanoimidazol-2-ylidene)(CO)2RhCl, a more π-acidic analogue. X-ray analysis of the aforementioned series of (NHC)(cod)RhCl
complexes indicated changes in N−Ccarbene bond lengths that were consistent with greater π-donation
from complexes containing 4,5-dihydroimidazol-2-ylidene relative to the their 4,5-dicyano analogues.
Collectively, these results suggest not only that imidazol-2-ylidenes are capable of π-back-bonding but
that this interaction may be tuned by changing the π-acidity of the substituents on the imidazole ring
Low back pain and risk factors for low back pain in car drivers
No full textThe cause of low back pain in populations of professional drivers is uncertain. A literature review
revealed factors that seem to be associated with low back pain (e.g. physical factors: exposure to
whole body-vibration, prolonged sitting posture, frequent lifting, pushing and pulling, lack of physical
fitness; psychosocial factors: job satisfaction or stress; individual factors: age, gender,
anthropometrics, tobacco, alcohol consumption, etc.).
This thesis investigates the occurrence of back pain in professional car drivers – a group found to
be not focussed upon in previous epidemiological studies. The thesis seeks to advance
understanding of response relationships between risk factors and low back pain in populations of
car drivers (209 taxi drivers and 365 police drivers) and 485 non-drivers. A longitudinal study with
cross-sectional baseline combined with field measurement of driving in selected vehicles was
performed to investigate the occurrence of musculoskeletal problems (mainly low back pain) and
the relationship between risk factors and low back pain experienced for at least one day during the
past 12 months in the two populations of professional drivers (taxi drivers and police drivers) and
professional non-drivers.
The cross-sectional baseline of the longitudinal study revealed that 45% (38.3-51.7%) of taxi
drivers, 53% (48-58.6%)of police drivers and 46% (41-50.1%) of police non-drivers reported low
back pain for at least one day during the past 12-months (p = 0.09). The prevalence of low back
pain in the non-driving population of police employees fell within prevalence range reported by
professional car drivers in this study and in previous epidemiological studies. The cross-sectional
study revealed risk factors associated with the prevalence of low back pain (i.e., stature, previous
physical demands, increased psychosomatic distress, daily and cumulative driving in taxi drivers;
age, lifting, bending, increase psychosomatic distress in police drivers; stature, bending, increased
psychosomatic distress in police non-drivers).
Measurements of whole-body vibration in selected taxi and police vehicles revealed frequencyweighted
accelerations in the dominant vibration direction (i.e., z-axis) to be 0.47 ms-2 r.m.s. in taxi
vehicles and 0.58 ms-2 r.m.s. in police vehicles.
A study of cumulative exposure to whole-body vibration in a group of taxi drivers pointed to a
possible overestimation of their self-estimated duration of vibration exposure by 31% on average.
The longitudinal study revealed a lower incidence of low back pain in taxi drivers than in both
police drivers and police non-drivers (p = 0.02). The difference might be attributed to a different
approach to low back pain in taxi drivers who lose income if unable to work. An alternative
explanation for increased low back pain among police employees could be that taxi drivers with low
back pain leave their profession and were excluded from the follow-up study – a healthy worker
effect.
The longitudinal study revealed that increased psychosomatic distress was a risk factor
associated with the development of new episodes of low back pain in all three of the studied
populations (i.e. taxi drivers and police drivers and non-drivers).
In police drivers, increased daily duration of driving was a risk factor for the development of low
back pain. Although the results point to increased incidence of low back pain with increasing
duration of daily driving, non-drivers were at a similar risk of developing of low back pain. Plausible
explanations for this finding include ergonomic factors that were present for both the drivers and the
non-drivers (e.g., the duration of sitting or duration in a constrained posture) and the presence of
other risk factors not investigated in the study but associated with increased incidence of low back
pain in non-drivers
Is training with the N-back task more effective than with other tasks? N-back vs. dichotic listening vs. simple listening
No full textCognitive training most commonly uses computerized tasks that stimulate simultaneous cognitive processing in two modalities, such as a dual n-back task with visual and auditive stimuli, or on two receptive channels, such as a listening task with dichotically presented stimuli. The present study was designed to compare a dual n-back task and a dichotic listening (DL) task with an active control condition (a simple listening task) and a no-training control condition for their impact on cognitive performance, daily life memory, and mindfulness. One hundred thirty healthy adults aged 18–55 years were randomly assigned to one of the four conditions. The training consisted of twenty 15-min sessions spread across 4 weeks. The results indicated some improvement on episodic memory tasks and a trend for enhanced performance in an untrained working memory (WM) span task following cognitive training relative to the no-training control group. However, the only differential training effects were found for the DL training in increasing choice reaction performance and a trend for self-reported mindfulness. Transfer to measures of fluid intelligence and memory in daily life did not emerge. Additionally, we found links between self-efficacy and n-back training performance and between emotion regulation and training motivation. Our results contribute to the field of WM training by demonstrating that our listening tasks are comparable in effect to a dual n-back task in slightly improving memory. The possibility of improving attentional control and mindfulness through dichotic listening training is promising and deserves further consideration
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