3,404 research outputs found
A comparative analysis of machine learning methods for classification type decision problems in healthcare
Advanced analytical techniques are gaining popularity in addressing complex classification type decision problems in many fields including healthcare and medicine. In this exemplary study, using digitized signal data, we developed predictive models employing three machine learning methods to diagnose an asthma patient based solely on the sounds acquired from the chest of the patient in a clinical laboratory. Although, the performances varied slightly, ensemble models (i.e., Random Forest and AdaBoost combined with Random Forest) achieved about 90% accuracy on predicting asthma patients, compared to artificial neural networks models that achieved about 80% predictive accuracy. Our results show that non-invasive, computerized lung sound analysis that rely on low-cost microphones and an embedded real-time microprocessor system would help physicians to make faster and better diagnostic decisions, especially in situations where x-ray and CT-scans are not reachable or not available. This study is a testament to the improving capabilities of analytic techniques in support of better decision making, especially in situations constraint by limited resources
Detection of metastable electronic states by Penning trap mass spectrometry
State-of-the-art optical clocks achieve fractional precisions of
and below using ensembles of atoms in optical lattices or individual ions in
radio-frequency traps. Promising candidates for novel clocks are highly charged
ions (HCIs) and nuclear transitions, which are largely insensitive to external
perturbations and reach wavelengths beyond the optical range, now becoming
accessible to frequency combs. However, insufficiently accurate atomic
structure calculations still hinder the identification of suitable transitions
in HCIs. Here, we report on the discovery of a long-lived metastable electronic
state in a HCI by measuring the mass difference of the ground and the excited
state in Re, the first non-destructive, direct determination of an electronic
excitation energy. This result agrees with our advanced calculations, and we
confirmed them with an Os ion with the same electronic configuration. We used
the high-precision Penning-trap mass spectrometer PENTATRAP, unique in its
synchronous use of five individual traps for simultaneous mass measurements.
The cyclotron frequency ratio of the ion in the ground state to the
metastable state could be determined to a precision of , unprecedented in the heavy atom regime. With a lifetime of about 130
days, the potential soft x-ray frequency reference at has a linewidth of only , and one of the highest electronic quality factor
() ever seen in an experiment. Our low
uncertainty enables searching for more HCI soft x-ray clock transitions, needed
for promising precision studies of fundamental physics in a thus far unexplored
frontier
The Effect of the Pairing Interaction on the Energies of Isobar Analog Resonances in Sb and Isospin Admixture in Sn Isotopes
In the present study, the effect of the pairing interaction and the isovector
correlation between nucleons on the properties of the isobar analog resonances
(IAR) in Sb isotopes and the isospin admixture in Sn
isotopes is investigated within the framework of the quasiparticle random phase
approximation (QRPA). The form of the interaction strength parameter is related
to the shell model potential by restoring the isotopic invariance of the
nuclear part of the total Hamiltonian. In this respect, the isospin admixtures
in the Sn isotopes are calculated, and the dependence of the
differential cross section and the volume integral for the
Sn(He,t)Sb reactions at E(He) MeV occurring by the excitation
of IAR on mass number A is examined. Our results show that the calculated value
for the isospin mixing in the Sn isotope is in good agreement with Colo
et al.'s estimates , and the obtained values for the volume integral
change within the error range of the value reported by Fujiwara et al.
(535 MeV fm). Moreover, it is concluded that although the
differential cross section of the isobar analog resonance for the (He,t)
reactions is not sensitive to pairing correlations between nucleons, a
considerable effect on the isospin admixtures in isotopes can be
seen with the presence of these correlations.Comment: 16 pages, 5 EPS figures and 2 tables, Late
Leaf-applied sodium chloride promotes cadmium accumulation in durum wheat grain
Cadmium (Cd) accumulation in durum wheat grain is a growing concern. Among the factors affecting Cd accumulation in plants, soil chloride (Cl) concentration plays a critical role. The effect of leaf NaCl application on grain Cd was studied in greenhouse-grown durum wheat (Triticum turgidum L. durum, cv. Balcali-2000) by immersing (10 s) intact flag leaves into Cd and/or NaCl-containing solutions for 14 times during heading and dough stages. Immersing flag leaves in solutions containing increasing amount of Cd resulted in substantial increases in grain Cd concentration. Adding NaCl alone or in combination with the Cd-containing immersion solution promoted accumulation of Cd in the grains, by up to 41%. In contrast, Zn concentrations of grains were not affected or even decreased by the NaCl treatments. This is likely due to the effect of Cl complexing Cd and reducing positive charge on the metal ion, an effect that is much smaller for Zn. Charge reduction or removal (CdCl2 0 species) would increase the diffusivity/lipophilicity of Cd and enhance its capability to penetrate the leaf epidermis and across membranes. Of even more significance to human health was the ability of Cl alone to penetrate leaf tissue and mobilize and enhance shoot Cd transfer to grains, yet reducing or not affecting Zn transfer
Testing HMA Density with Electromagnetic Gauges
Electromagnetic gauges offer nondestructive testing of in-place HMA with real-time results for effective QC/QA decision making
Investigation of Electromagnetic Gauges for Determining In-Place HMA Density
Density is an important component of hot-mix asphalt (HMA) pavement quality and long-term performance. Insufficient density of an in-place HMA pavement is the most frequently cited construction-related performance problem.
This study evaluated the use of electromagnetic gauges to nondestructively determine densities. Field and laboratory measurements were taken with two electromagnetic gauges—a PaveTracker and a Pavement Quality Indicator (PQI). Test data were collected in the field during and after paving operations and also in a laboratory on field mixes compacted in the lab.
This study revealed that several mix- and project-specific factors affect electromagnetic gauge readings. Consequently, the implementation of these gauges will likely need to be done utilizing a test strip on a project- and mix-specific basis to appropriately identify an adjustment factor for the specific electromagnetic gauge being used for quality control and quality assurance (QC/QA) testing. The substantial reduction in testing time that results from employing electromagnetic gauges rather than coring makes it possible for more readings to be used in the QC/QA process with real-time information without increasing the testing costs
Cultural Implications of a Study of Police Communication With Minorities
Recent protests and riots around the globe have renewed the call for police reform. While police reforms could benefit the police and the public, police training in cultural awareness, racial biases, and communications may result in better and faster changes in police attitudes and approaches for working with minorities. This study suggests that non-police public safety personnel perceive a greater need for police training than the police. The study examined the police relationship and their communication with minority populations as perceived by Kosovo police (N=20) and other public safety personnel (N=24). Respondents answered a quantitative survey. Although not statistically significant, it appears that most police respondents didn’t recognize that cultural barriers exist between minorities and police, and they didn’t feel a strong need for cultural training. On the other hand, other public safety personnel showed greater support for cultural training, recognizing that cultural barriers do exist between police and minorities. Both groups agreed that trust is more important than speaking the same language when working with minorities
Drug discovery for male subfertility using high-throughput screening:a new approach to an unsolved problem
STUDY QUESTIONCan pharma drug discovery approaches be utilized to transform investigation into novel therapeutics for male infertility?SUMMARY ANSWERHigh-throughput screening (HTS) is a viable approach to much-needed drug discovery for male factor infertility.WHAT IS KNOWN ALREADYThere is both huge demand and a genuine clinical need for new treatment options for infertile men. However, the time, effort and resources required for drug discovery are currently exorbitant, due to the unique challenges of the cellular, physical and functional properties of human spermatozoa and a lack of appropriate assay platform.STUDY DESIGN, SIZE, DURATIONSpermatozoa were obtained from healthy volunteer research donors and subfertile patients undergoing IVF/ICSI at a hospital-assisted reproductive techniques clinic between January 2012 and November 2016.PARTICIPANTS/MATERIALS, SETTING, METHODSA HTS assay was developed and validated using intracellular calcium ([Ca2+]i) as a surrogate for motility in human spermatozoa. Calcium fluorescence was detected using a Flexstation microplate reader (384-well platform) and compared with responses evoked by progesterone, a compound known to modify a number of biologically relevant behaviours in human spermatozoa. Hit compounds identified following single point drug screen (10 μM) of an ion channel-focussed library assembled by the University of Dundee Drug Discovery Unit were rescreened to ensure potency using standard 10 point half-logarithm concentration curves, and tested for purity and integrity using liquid chromatography and mass spectrometry. Hit compounds were grouped by structure activity relationships and five representative compounds then further investigated for direct effects on spermatozoa, using computer-assisted sperm assessment, sperm penetration assay and whole-cell patch clamping.MAIN RESULTS AND THE ROLE OF CHANCEOf the 3242 ion channel library ligands screened, 384 compounds (11.8%) elicited a statistically significant increase in calcium fluorescence, with greater than 3× median absolute deviation above the baseline. Seventy-four compounds eliciting ≥50% increase in fluorescence in the primary screen were rescreened and evaluated further, resulting in 48 hit compounds that produced a concentration-dependent increase in [Ca2+]i. Sperm penetration studies confirmed in vitro exposure to two hit compounds (A and B) resulted in significant improvement in functional motility in spermatozoa from healthy volunteer donors (A: 1 cm penetration index 2.54, 2 cm penetration index 2.49; P < 0.005 and B: 1 cm penetration index 2.1, 2 cm penetration index 2.6; P < 0.005), but crucially, also in patient samples from those undergoing fertility treatment (A: 1 cm penetration index 2.4; P = 0.009, 2 cm penetration index 3.6; P = 0.02 and B: 1 cm penetration index 2.2; P = 0.0004, 2 cm penetration index 3.6; P = 0.002). This was primarily as a result of direct or indirect CatSper channel action, supported by evidence from electrophysiology studies of individual sperm.LIMITATIONS, REASONS FOR CAUTIONIncrease and fluxes in [Ca2+]i are fundamental to the regulation of sperm motility and function, including acrosome reaction. The use of calcium signalling as a surrogate for sperm motility is acknowledged as a potential limitation in this study.WIDER IMPLICATIONS OF THE FINDINGSWe conclude that HTS can robustly, efficiently, identify novel compounds that increase [Ca2+]i in human spermatozoa and functionally modify motility, and propose its use as a cornerstone to build and transform much-needed drug discovery for male infertility.</p
Impact of Early-Age Behaviors on Pavement Smoothness
Knowledge of how pavement temperature variations affect pavement curvature is essential for understanding the effects on joint shifting, vertical slab movement, and overall pavement smoothness
Energy Response and Longitudinal Shower Profiles Measured in CMS HCAL and Comparison With Geant4
The response of the CMS combined electromagnetic and hadron calorimeter to beams of pions with momenta in the range 5-300 GeV/c has been measured in the H2 test beam at CERN. The raw response with the electromagnetic compartment calibrated to electrons and the hadron compartment calibrated to 300 GeV pions may be represented by sigma = (1.2) sqrt{E} oplus (0.095) E. The fraction of energy visible in the calorimeter ranges from 0.72 at 5 GeV to 0.95 at 300 GeV, indicating a substantial nonlinearity. The intrinsic electron to hadron ratios are fit as a function of energy and found to be in the range 1.3-2.7 for the electromagnetic compartment and 1.4-1.8 for the hadronic compartment. The fits are used to correct the non-linearity of the e pi response to 5% over the entire measured range resulting in a substantially improved resolution at low energy. Longitudinal shower profile have been measured in detail and compared to Geant4 models, LHEP-3.7 and QGSP-2.8. At energies below 30 GeV, the data, LHEP and QGSP are in agreement. Above 30 GeV, LHEP gives a more accurate simulation of the longitudinal shower profile
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