1,723 research outputs found
Multi-band optical variability of three TeV Blazars on Diverse Timescales
We present our optical photometric observations of three TeV blazars, PKS
1510-089, PG 1553+113 and Mrk 501 taken using two telescopes in India, one in
Bulgaria, one in Greece and one in Serbia during 2012 - 2014. These
observations covered a total of 95 nights with a total of 202 B filter frames,
247 images in V band, 817 in R band while 229 images were taken in the I
filter. This work is focused on multi-band flux and colour variability studies
of these blazars on diverse timescales which are useful in understanding the
emission mechanisms. We studied the variability characteristics of above three
blazars and found all to be active over our entire observational campaigns. We
also searched for any correlation between the brightness of the sources and
their colour indices. During the times of variability, no significant evidence
for the sources to display spectral changes correlated with magnitude was found
on timescales of a few months. We briefly discuss the possible physical
mechanisms most likely responsible for the observed flux variability.Comment: 11 pages, 7 figures, 9 tables. Accepted for publication in MNRA
Pengaruh Partisipasi Penyusunan Anggaran terhadap Kinerja Manajerial dengan Gaya Kepemimpinan, Motivasi dan Job Relevant Information sebagai Variabel Intervening
This study aimed to determine (1) the effect of budgetaryparticipation on managerial performance in the preparation of thebudget, (2) the effect of leadership style on the relationship betweenbudgetary participation and managerial performance, (3) the effect ofmotivation on the relationship between budgetary participation andmanagerial performance, and (4) the effect of job relevantinformation on the relationshipbetween budgetary participation andmanagerial performance. The subjects of this study are all managersin bank Riau Kepri. The data was collected by distributingquestionnaires to 138 respondents, but only 85 respondents who fillout the questionnaires. The analysis tool is using Partial Least Square(PLS) program version 2.0. The result show that budgetaryparticipation has positive and significant effect on managerialperformance. Furthermore, job relevant information has positive andsignificant effect with budgetary participation and the managerialperformance. The data of this study failed to support the mediatingrate of leadership style and motivation on the relationship betweenbudgetary participation and the managerial performance
Spitzer Warm Mission Transition and Operations
Following the successful dynamic planning and implementation of IRAC Warm Instrument Characterization activities, transition to Spitzer Warm Mission operations has gone smoothly. Operation teams procedures and processes required minimal adaptation and the overall composition of the Mission Operation System retained the same functionality it had during the Cryogenic Mission. While the warm mission scheduling has been simplified because all observations are now being made with a single instrument, several other differences have increased the complexity. The bulk of the observations executed to date have been from ten large Exploration Science programs that, combined, have more complex constraints, more observing requests, and more exo-planet observations with durations of up to 145 hours. Communication with the observatory is also becoming more challenging as the Spitzer DSN antenna allocations have been reduced from two tracking passes per day to a single pass impacting both uplink and downlink activities. While IRAC is now operating with only two channels, the data collection rate is roughly 60% of the four-channel rate leaving a somewhat higher average volume collected between the less frequent passes. Also, the maximum downlink data rate is decreasing as the distance to Spitzer increases requiring longer passes. Nevertheless, with well over 90% of the time spent on science observations, efficiency has equaled or exceeded that achieved during the cryogenic mission
Age-Related Changes in Processing Speed: Unique Contributions of Cerebellar and Prefrontal Cortex
Age-related declines in processing speed are hypothesized to underlie the widespread changes in cognition experienced by older adults. We used a structural covariance approach to identify putative neural networks that underlie age-related structural changes associated with processing speed for 42 adults ranging in age from 19 to 79 years. To characterize a potential mechanism by which age-related gray matter changes lead to slower processing speed, we examined the extent to which cerebral small vessel disease influenced the association between age-related gray matter changes and processing speed. A frontal pattern of gray matter and white matter variation that was related to cerebral small vessel disease, as well as a cerebellar pattern of gray matter and white matter variation were uniquely related to age-related declines in processing speed. These results demonstrate that at least two distinct factors affect age-related changes in processing speed, which might be slowed by mitigating cerebral small vessel disease and factors affecting declines in cerebellar morphology
Coagulation Profiles in Humans Exposed to Exertional Hypobaric Decompression Stress Determined by Calibrated Automated Thrombogram
Citation: Madden, L.A.; Vince, R.V.; Edwards, V.C.; Lee, V.M.; Connolly, D.M. Coagulation Profiles in Humans Abstract: The blood coagulation response to decompression stress in humans has yet to be fully investigated. Here we utilised calibrated automated thrombogram (CAT) on samples from healthy volunteers exposed to decompression stress to investigate real-time thrombin generation. To induce decompression stress, fifteen apparently healthy males (age 20-50 yr) were exposed to two consecutive ascents to 25,000 ft for 60 min (1st ascent) and then 90 min (2nd ascent) while breathing 100% oxygen. Citrated blood samples were taken prior to exposure (T0), following the 2nd ascent (T8) and at 24 h (T24). Thrombin generation curves were obtained using Thrombinoscope TM. Parameters determined were lag time (LAG), time to peak (TTP), peak thrombin (PEAK), endogenous thrombin potential (ETP) and velocity index (VEL). Of the 15 subjects, 12 had validated coagulation profiles. TTP and ETP showed no significant differences. However, there was a significant increase in VEL from T0 to T8 (p = 0.025) and from T8 to T24 (p = 0.043). A non-significant trend of an overall increase in PEAK was also observed from T0 to T8 (p = 0.069) and from T8 to T24 (p = 0.098). PEAK and VEL were found to be correlated. Taken together, these two parameters suggest an overall shift towards a more procoagulant profile following hypobaric stress
Organizational learning and emotion: constructing collective meaning in support of strategic themes
Missing in the organizational learning literature is an integrative framework that reflects the emotional as well as the cognitive dynamics involved. Here, we take a step in this direction by focusing in depth over time (five years) on a selected organization which manufactures electronic equipment for the office industry. Drawing on personal construct theory, we define organizational learning as the collective re-construal of meaning in the direction of strategically significant themes. We suggest that emotions arise as members reflect on progress or lack of progress in achieving organizational learning. Our evidence suggests that invalidation – where organizational learning fails to correspond with expectations – gives rise to anxiety and frustration, while validation – where organizational learning is aligned with or exceeds expectations – evokes comfort or excitement. Our work aims to capture the key emotions involved as organizational learning proceeds
Sources and sinks separating domains of left- and right-traveling waves: Experiment versus amplitude equations
In many pattern forming systems that exhibit traveling waves, sources and
sinks occur which separate patches of oppositely traveling waves. We show that
simple qualitative features of their dynamics can be compared to predictions
from coupled amplitude equations. In heated wire convection experiments, we
find a discrepancy between the observed multiplicity of sources and theoretical
predictions. The expression for the observed motion of sinks is incompatible
with any amplitude equation description.Comment: 4 pages, RevTeX, 3 figur
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