1,028 research outputs found
NMR-based assignment of isoleucine vs allo-isoleucine stereochemistry
A simple 1H and 13C NMR spectrometric analysis is demonstrated that permits differentiation of isoleucine and allo-isoleucine residues by inspection of the chemical shift and coupling constants of the signals associated with the proton and carbon at the α-stereocentre. This is applied to the estimation of epimerisation during metal-free N-arylation and peptide coupling reactions
Infant lung function tests as endpoints in the ISIS multicenter clinical trial in cystic fibrosis
BACKGROUND:
The Infant Study of Inhaled Saline (ISIS) in CF was the first multicenter clinical trial to utilize infant pulmonary function tests (iPFTs) as an endpoint.
METHODS:
Secondary analysis of ISIS data was conducted in order to assess feasibility of iPFT measures and their associations with respiratory symptoms. Standard deviations were calculated to aid in power calculations for future clinical trials.
RESULTS:
Seventy-three participants enrolled, 70 returned for the final visit; 62 (89%) and 45 (64%) had acceptable paired functional residual capacity (FRC) and raised volume measurements, respectively. Mean baseline FEV0.5, FEF75 and FRC z-scores were 0.3 (SD: 1.2), -0.2 (SD: 2.0), and 1.8 (SD: 2.0).
CONCLUSIONS:
iPFTs are not appropriate primary endpoints for multicenter clinical trials due to challenges of obtaining acceptable data and near-normal average raised volume measurements. Raised volume measures have potential to serve as secondary endpoints in future clinical CF trials
Testing the Blazar Sequence with Spectra of Recently Discovered Dim Blazars from the Fermi Unassociated Catalog
Recent works have developed samples of blazars from among the Fermi-LAT
unassociated sources via machine learning comparisons with known blazar
samples. Continued analysis of these new blazars tests the predictions of the
blazar sequence and enables more flux-complete samples of blazars as a
population. Using Fermi, Swift, WISE, and archival radio data, we construct
broadband spectral energy distributions for 106 recently identified blazars.
Drawn from the unassociated 4FGL source sample, this new sample has a lower
median flux than the overall sample of gamma-ray blazars. By measuring the
synchrotron peak frequency, we compare our sample of new blazars with known
blazars from the 4LAC catalog. We find that the bulk of the new blazars are
similar to High-Synchrotron Peak (HSP) BL Lac objects, with a higher median
synchrotron peak; the sample has a median via
BLaST peak estimation, compared to for the
4LAC BL Lacs. Finally, we conduct synchrotron self-Compton (SSC) leptonic
modeling, comparing fitted physical and phenomenological properties to brighter
blazars. We find that the new blazars have smaller characteristic Lorentz
factors and fitted magnetic fields , in agreement with
blazar sequence predictions. The new blazars have slightly higher Compton
dominance ratios than expected, which may point to alternative emission models
for these dim blazars. Our results extend the predictions of the blazar
sequence to a sample of dimmer blazars, confirming the broad predictions of
that theory.Comment: 13 pages main body with 10 figures. 8 pages of data table
Understanding the Investment Behavior of Millennial Certified Public Accountants (CPA) in General Santos City
It examines the investment behavior of millennial Certified Public Accountants (CPAs) in General Santos City, Philippines, focusing on how financial financial capability in terms of financial knowledge, financial attitude, and financial stability influence their investment decisions. The research uses a quantitative, descriptive-correlational design, with survey questionnaires distributed to 83 millennial CPAs. By analyzing the demographic and investment profiles of the respondents, the study aims to understand how these factors impact investment frequency, risk management, portfolio diversification, and overall investment decision-making. The findings highlight the challenges young professionals face in making informed and disciplined investment choices, despite their strong financial knowledge. The study also provides recommendations for enhancing financial education and encouraging responsible investment practices, contributing to the development of strategies that promote long-term wealth-building among millennials
The sound and the fury: Nudgee College showcase evening
This documentary captures the preparation towards the showcase evening of a school/university partnership between St Joseph's Nudgee College and the University of Southern Queensland based on a Queensland Anzac Centenary Grant and an Australian Government Arts and Culture Public Fund Grant. The outputs included an evening sound and light show, exhibitions, and a children's picture book which were shared with the school and wider community on October 24, 2015 as part of the Anzac Centenary Commemorations in Australia
Anaerobic Carbon Monoxide Dehydrogenase Diversity in the Homoacetogenic Hindgut Microbial Communities of Lower Termites and the Wood Roach
Anaerobic carbon monoxide dehydrogenase (CODH) is a key enzyme in the Wood-Ljungdahl (acetyl-CoA) pathway for acetogenesis performed by homoacetogenic bacteria. Acetate generated by gut bacteria via the acetyl-CoA pathway provides considerable nutrition to wood-feeding dictyopteran insects making CODH important to the obligate mutualism occurring between termites and their hindgut microbiota. To investigate CODH diversity in insect gut communities, we developed the first degenerate primers designed to amplify cooS genes, which encode the catalytic (β) subunit of anaerobic CODH enzyme complexes. These primers target over 68 million combinations of potential forward and reverse cooS primer-binding sequences. We used the primers to identify cooS genes in bacterial isolates from the hindgut of a phylogenetically lower termite and to sample cooS diversity present in a variety of insect hindgut microbial communities including those of three phylogenetically-lower termites, Zootermopsis nevadensis, Reticulitermes hesperus, and Incisitermes minor, a wood-feeding cockroach, Cryptocercus punctulatus, and an omnivorous cockroach, Periplaneta americana. In total, we sequenced and analyzed 151 different cooS genes. These genes encode proteins that group within one of three highly divergent CODH phylogenetic clades. Each insect gut community contained CODH variants from all three of these clades. The patterns of CODH diversity in these communities likely reflect differences in enzyme or physiological function, and suggest that a diversity of microbial species participate in homoacetogenesis in these communities
Using ordinal logistic regression to evaluate the performance of laser-Doppler predictions of burn-healing time
Background
Laser-Doppler imaging (LDI) of cutaneous blood flow is beginning to be used by burn surgeons to predict the healing time of burn wounds; predicted healing time is used to determine wound treatment as either dressings or surgery. In this paper, we do a statistical analysis of the performance of the technique.
Methods
We used data from a study carried out by five burn centers: LDI was done once between days 2 to 5 post burn, and healing was assessed at both 14 days and 21 days post burn. Random-effects ordinal logistic regression and other models such as the continuation ratio model were used to model healing-time as a function of the LDI data, and of demographic and wound history variables. Statistical methods were also used to study the false-color palette, which enables the laser-Doppler imager to be used by clinicians as a decision-support tool.
Results
Overall performance is that diagnoses are over 90% correct. Related questions addressed were what was the best blood flow summary statistic and whether, given the blood flow measurements, demographic and observational variables had any additional predictive power (age, sex, race, % total body surface area burned (%TBSA), site and cause of burn, day of LDI scan, burn center). It was found that mean laser-Doppler flux over a wound area was the best statistic, and that, given the same mean flux, women recover slightly more slowly than men. Further, the likely degradation in predictive performance on moving to a patient group with larger %TBSA than those in the data sample was studied, and shown to be small.
Conclusion
Modeling healing time is a complex statistical problem, with random effects due to multiple burn areas per individual, and censoring caused by patients missing hospital visits and undergoing surgery. This analysis applies state-of-the art statistical methods such as the bootstrap and permutation tests to a medical problem of topical interest. New medical findings are that age and %TBSA are not important predictors of healing time when the LDI results are known, whereas gender does influence recovery time, even when blood flow is controlled for.
The conclusion regarding the palette is that an optimum three-color palette can be chosen 'automatically', but the optimum choice of a 5-color palette cannot be made solely by optimizing the percentage of correct diagnoses
Using Neural Networks to Differentiate Newly Discovered BL Lacs and FSRQs among the 4FGL Unassociated Sources Employing Gamma-ray, X-ray, UV/Optical and IR Data
Among the ~2157 unassociated sources in the third data release (DR3) of the
fourth Fermi catalog, ~1200 were observed with the Neil Gehrels Swift
Observatory pointed instruments. These observations yielded 238 high S/N X-ray
sources within the 95% Fermi uncertainty regions. Recently, Kerby et al.
employed neural networks to find blazar candidates among these 238 X-ray
counterparts to the 4FGL unassociated sources and found 112 likely blazar
counterpart sources. A complete sample of blazars, along with their
sub-classification, is a necessary step to help understand the puzzle of the
blazar sequence and for the overall completeness of the gamma-ray emitting
blazar class in the Fermi catalog. We employed a multi-perceptron neural
network classifier to identify FSRQs and BL Lacs among these 112 blazar
candidates using the gamma-ray, X-ray, UV/optical, and IR properties. This
classifier provided probability estimates for each source to be associated with
one or the other category, such that P_fsrq represents the probability for a
source to be associated with the FSRQ subclass. Using this approach, 4 FSRQs
and 50 BL Lacs are classified as such with >99% confidence, while the remaining
58 blazars could not be unambiguously classified as either BL Lac or FSRQ.Comment: Accepted for publication in A
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