The applicability of the "surprise question" as a prognostic tool in patients with severe chronic comorbidities in a university teaching outpatient setting

BACKGROUND

Life expectancy in recent decades has increased the prevalence of chronic diseases in the population, requiring an approach to new health topics, such as discussions on quality of life and expectations about death and dying. The concept of advance directives (ADs) gives individuals the opportunity to make known their decisions about the treatments they would like to receive at the end of life. Despite the recognition of relevance in clinical practice, the applicability of the concept presents challenges, including establishing the appropriate prognosis for each patient and the ideal time to approach the patient. Some prognostic tools were developed, such as the surprise question (SQ): "Would you be surprised if your patient died in 12 months?", which is used in some clinical settings to predict patient deaths and to make decisions regarding ADs. The main objective of the present study was to evaluate the behavior of second-year resident physicians (PGY-2) when the SQ was applied.

METHOD

In our observational study, from July 1, 2016, to February 28, 2017, (PGY-2) in the Internal Medicine Residency Program (IMRP) applied SQ to all patients with multiple and varied chronic no communicable comorbidities, who were followed up at the general medicine outpatient clinic (GMOC) of a tertiary university hospital in São Paulo- Brazil. The frequency of the outcome (death or non-death within 12 months) was analyzed by correlating it with the clinical data (impact of the studied variables).

RESULTS

Eight hundred forty patients entered the study. Fitfty-two of them (6.2%) died within one year. PGY-2 predicted that two hundred and fourteen patients (25.5% of total) would die within a year (answer No to SQ), of which, 32 (14.9%) did so. The correct residents' prognosis for the subgroup of 626 patients (answer "Yes" to SQ) was NPV = 96.8% (CI = 95.4%-98.2%) and PPV = 14.9% (CI 10.1%-19, 6%). Answering "Yes" to SQ correlated negatively to addressing AD while the outcomes death and the answer No to SQ were positively correlated, according to the number of comorbidities.

CONCLUSION

The SQ, in addition to care, contributed to health education, communication and care planning shared by the doctor and patient.

Improved Measurement of the Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

Reactor neutrino experiments play a crucial role in advancing our knowledge of neutrinos. In this Letter, the evolution of the flux and spectrum as a function of the reactor isotopic content is reported in terms of the inverse-beta-decay yield at Daya Bay with 1958 days of data and improved systematic uncertainties. These measurements are compared with two signature model predictions: the Huber-Mueller model based on the conversion method and the SM2018 model based on the summation method. The measured average flux and spectrum, as well as the flux evolution with the ^{239}Pu isotopic fraction, are inconsistent with the predictions of the Huber-Mueller model. In contrast, the SM2018 model is shown to agree with the average flux and its evolution but fails to describe the energy spectrum. Altering the predicted inverse-beta-decay spectrum from ^{239}Pu fission does not improve the agreement with the measurement for either model. The models can be brought into better agreement with the measurements if either the predicted spectrum due to ^{235}U fission is changed or the predicted ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu spectra are changed in equal measure.

Precision Measurement of Reactor Antineutrino Oscillation at Kilometer-Scale Baselines by Daya Bay

We present a new determination of the smallest neutrino mixing angle θ_{13} and the mass-squared difference Δm_{32}^{2} using a final sample of 5.55×10^{6} inverse beta-decay (IBD) candidates with the final-state neutron captured on gadolinium. This sample is selected from the complete dataset obtained by the Daya Bay reactor neutrino experiment in 3158 days of operation. Compared to the previous Daya Bay results, selection of IBD candidates has been optimized, energy calibration refined, and treatment of backgrounds further improved. The resulting oscillation parameters are sin^{2}2θ_{13}=0.0851±0.0024, Δm_{32}^{2}=(2.466±0.060)×10^{-3}  eV^{2} for the normal mass ordering or Δm_{32}^{2}=-(2.571±0.060)×10^{-3}  eV^{2} for the inverted mass ordering.

Building a Low-Cost Wireless Biofeedback Solution: Applying Design Science Research Methodology

In recent years, affective computing has emerged as a promising approach to studying user experience, replacing subjective methods that rely on participants' self-evaluation. Affective computing uses biometrics to recognize people's emotional states as they interact with a product. However, the cost of medical-grade biofeedback systems is prohibitive for researchers with limited budgets. An alternative solution is to use consumer-grade devices, which are more affordable. However, these devices require proprietary software to collect data, complicating data processing, synchronization, and integration. Additionally, researchers need multiple computers to control the biofeedback system, increasing equipment costs and complexity. To address these challenges, we developed a low-cost biofeedback platform using inexpensive hardware and open-source libraries. Our software can serve as a system development kit for future studies. We conducted a simple experiment with one participant to validate the platform's effectiveness, using one baseline and two tasks that elicited distinct responses. Our low-cost biofeedback platform provides a reference architecture for researchers with limited budgets who wish to incorporate biometrics into their studies. This platform can be used to develop affective computing models in various domains, including ergonomics, human factors engineering, user experience, human behavioral studies, and human-robot interaction.

Time Pressure Affects the Risk Preference and Outcome Evaluation

It is ubiquitous that food delivery riders do not have unlimited periods of time for deliberation to make decisions. Time pressure plays a significant role in decision-making processes. This study investigated how time pressure affected risk preference and outcome evaluation through behavioral and electrophysiological responses during decision-making. Participants finished a simple gambling task under three different time constraint conditions (high/medium/low). Behavioral and event-related potentials (ERPs) data were recorded during the experiment. The results showed that the decision time of people was shorter under high time pressure than under medium and low time pressures. People tend to make more risky choices when under high time pressure. The feedback-related negativity (FRN) amplitude was smaller in the high time pressure than in medium and low time pressure conditions. These findings provided evidence that time pressure has an impact on the risk decision-making process.

Observation of a Strongly Isospin-Mixed Doublet in ^{26}Si via β-Delayed Two-Proton Decay of ^{26}P

β decay of proton-rich nuclei plays an important role in exploring isospin mixing. The β decay of ^{26}P at the proton drip line is studied using double-sided silicon strip detectors operating in conjunction with high-purity germanium detectors. The T=2 isobaric analog state (IAS) at 13 055 keV and two new high-lying states at 13 380 and 11 912 keV in ^{26}Si are unambiguously identified through β-delayed two-proton emission (β2p). Angular correlations of two protons emitted from ^{26}Si excited states populated by ^{26}P β decay are measured, which suggests that the two protons are emitted mainly sequentially. We report the first observation of a strongly isospin-mixed doublet that deexcites mainly via two-proton decay. The isospin mixing matrix element between the ^{26}Si IAS and the nearby 13 380-keV state is determined to be 130(21) keV, and this result represents the strongest mixing, highest excitation energy, and largest level spacing of a doublet ever observed in β-decay experiments.

Effects of virtual target size, position, and parallax on vergence-accommodation conflict as estimated by actual gaze

Due to the increased utilization of stereoscopic displays, the scope of the vergence-accommodation conflict has been studied extensively to reveal how the human visual system operates. The purpose of this work was to study the phenomenon of vergence-accommodation conflict by comparing the theoretical eye vergence angle (vergence response) and gaze-based eye vergence angle (vergence stimulus) based on eye tracker gaze data. The results indicated that the gaze-based eye vergence angle was largest at the greatest parallax. The result also revealed that the eye vergence angle accuracy was significantly highest at the nearest parallax. Generally, accuracy improves when virtual objects are put in the middle and close to participants' positions. Moreover, the signed error decreases significantly when the virtual object is in the middle. Based on the results of this study, we can gain a greater understanding of the vergence-accommodation conflict in the stereoscopic environment.

First Measurement of High-Energy Reactor Antineutrinos at Daya Bay

This Letter reports the first measurement of high-energy reactor antineutrinos at Daya Bay, with nearly 9000 inverse beta decay candidates in the prompt energy region of 8-12 MeV observed over 1958 days of data collection. A multivariate analysis is used to separate 2500 signal events from background statistically. The hypothesis of no reactor antineutrinos with neutrino energy above 10 MeV is rejected with a significance of 6.2 standard deviations. A 29% antineutrino flux deficit in the prompt energy region of 8-11 MeV is observed compared to a recent model prediction. We provide the unfolded antineutrino spectrum above 7 MeV as a data-based reference for other experiments. This result provides the first direct observation of the production of antineutrinos from several high-Q_{β} isotopes in commercial reactors.

Joint Determination of Reactor Antineutrino Spectra from ^{235}U and ^{239}Pu Fission by Daya Bay and PROSPECT

A joint determination of the reactor antineutrino spectra resulting from the fission of ^{235}U and ^{239}Pu has been carried out by the Daya Bay and PROSPECT Collaborations. This Letter reports the level of consistency of ^{235}U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The combined analysis reduces the degeneracy between the dominant ^{235}U and ^{239}Pu isotopes and improves the uncertainty of the ^{235}U spectral shape to about 3%. The ^{235}U and ^{239}Pu antineutrino energy spectra are unfolded from the jointly deconvolved reactor spectra using the Wiener-SVD unfolding method, providing a data-based reference for other reactor antineutrino experiments and other applications. This is the first measurement of the ^{235}U and ^{239}Pu spectra based on the combination of experiments at low- and highly enriched uranium reactors.

Large Isospin Asymmetry in ^{22}Si/^{22}O Mirror Gamow-Teller Transitions Reveals the Halo Structure of ^{22}Al

β-delayed one-proton emissions of ^{22}Si, the lightest nucleus with an isospin projection T_{z}=-3, are studied with a silicon array surrounded by high-purity germanium detectors. Properties of β-decay branches and the reduced transition probabilities for the transitions to the low-lying states of ^{22}Al are determined. Compared to the mirror β decay of ^{22}O, the largest value of mirror asymmetry in low-lying states by far, with δ=209(96), is found in the transition to the first 1^{+} excited state. Shell-model calculation with isospin-nonconserving forces, including the T=1, J=2, 3 interaction related to the s_{1/2} orbit that introduces explicitly the isospin-symmetry breaking force and describes the loosely bound nature of the wave functions of the s_{1/2} orbit, can reproduce the observed data well and consistently explain the observation that a large δ value occurs for the first but not for the second 1^{+} excited state of ^{22}Al. Our results, while supporting the proton-halo structure in ^{22}Al, might provide another means to identify halo nuclei.

The development of a mobile user interface ability evaluation system for the elderly

This research aimed to develop a comprehensive evaluation of the mobile user interface abilities of the elderly so that technology can be designed to meet individualized needs. A total of 135 older adults were evaluated with the developed system, the Elderly Mobile User Interface Ability Evaluation System (EMUIAES). The prediction of age and the use of technology on elderly mobile interface usage were investigated based on the findings of the evaluation. The relationship between performance on Fitts' task and elderly mobile user interface ability (EMUIA) was also examined. The findings showed a strong effect of age on the elderly's use of mobile user interfaces. Previous experience with personal and tablet computers also contributed to the use of mobile user interfaces. In addition, this research demonstrated the application of Fitts' law to describe the elderly mobile user interface behaviors, particularly for tasks involving fast tapping and pointing. The EMUIAES can provide future researchers and designers a comprehensive tool to describe the elderly's diverse behaviors and changes in their ability to use mobile interfaces. Individualized interface designs for elderly users can be developed based on these findings to improve the elderly users' experiences of using technology.

[The effects of vestibular rehabilitation training on the symptoms of vertigo and disability in patients with vestibular peripheral vertigo]

Objective: To compare the effects of vestibular rehabilitation training and drug therapy on the symptoms of vertigo and disability in patients with vestibular peripheral vertigo. Methods: This prospective study was enrolled 43 patients with vestibular peripheral vertigo who admitted to the outpatient department of Eye & ENT Hospital of Fudan University from January 2018 to December 2018. They were randomly divided into two groups: control group (drug treatment group) and experimental group (drug treatment combined rehabilitation training group). All patients filled in the first vertigo disability rating scale (DHI), specific activity balance confidence scale (ABC) and anxiety self-rating scale (SAS) on the day of treatment and at two, four and eight weeks after treatment intervention, and the data were statistically analyzed. Results: There was no significant difference in gender, age and body weight between the two groups (P>0.05). After treatment (Control group (4w) : DHI (45.5±30.6) , ABC (86.9±12.4) , SAS (37.9±8.2) Experimental group (8w) : DHI (34.8±28.5) , SAS (35.7±7.9) ) , the three scales of the two groups were better than before treatment (Control group: DHI (59.2±25.9) , ABC (79.7±16.7) ,SAS (41.1±6.8) ; Experimental group: DHI (55.2±20.5) , ABC (80.3±18.3) , SAS (41.9±9.1) ) . The comparison of data before and after treatment in each group according to treatment time indicated that DHI and ABC scores in the experimental group showed that the DHI and ABC scores of the experimental group changed significantly at 2 weeks after treatment, and the SAS scores changed at 4 weeks after treatment. The difference was statistically significant (P<0.05). However, there was a statistically significant difference between the control group DHI score 4 weeks after treatment and SAS score 8 weeks after treatment (P<0.05). ABC score did not show statistical difference (P>0.05). Conclusion: The subjective symptoms and anxiety of vertigo and disability in the two groups improved obviously after treatment. Compared with drug therapy alone, drug therapy combined with vestibular rehabilitation training can significantly improve patients' subjective symptoms of vertigo and disability, as well as their anxiety and depression, so as to improve their overall quality of life.

Improved Constraints on Sterile Neutrino Mixing from Disappearance Searches in the MINOS, MINOS+, Daya Bay, and Bugey-3 Experiments

Searches for electron antineutrino, muon neutrino, and muon antineutrino disappearance driven by sterile neutrino mixing have been carried out by the Daya Bay and MINOS+ collaborations. This Letter presents the combined results of these searches, along with exclusion results from the Bugey-3 reactor experiment, framed in a minimally extended four-neutrino scenario. Significantly improved constraints on the θ_{μe} mixing angle are derived that constitute the most constraining limits to date over five orders of magnitude in the mass-squared splitting Δm_{41}^{2}, excluding the 90% C.L. sterile-neutrino parameter space allowed by the LSND and MiniBooNE observations at 90% CL_{s} for Δm_{41}^{2}<13  eV^{2}. Furthermore, the LSND and MiniBooNE 99% C.L. allowed regions are excluded at 99% CL_{s} for Δm_{41}^{2}<1.6 eV^{2}.

Prediction of the use of mobile device interfaces in the progressive aging process with the model of Fitts' law

PURPOSE

As the population ages, so do the potential users of technology, and older adults' behaviors when using mobile device interfaces are becoming increasingly important. A representative model for detecting older adults' behaviors and performance on the use of mobile device interfaces is needed to provide individualized designs. This research aimed to investigate the applicability of the broadly used model of Fitts' law to detect the progressive changes in the use of mobile device interfaces in older adults. The effect of experience with using technology on performance on a Fitts task was also examined.

METHOD

A sample of 135 older adults was recruited to test the application of Fitts' model to the use of technology by older adult users. Each participant was asked to finish tasks at 9 levels of difficulty, from easy to difficult, in a multidirectional tapping task. Analysis of variance was employed to examine the effect of age on performance on the Fitts task, movement time, and the standard deviation of movement time. Stepwise regression was used to investigate how well age and technology use could predict performance on the Fitts task.

RESULT

Performance on the Fitts task was sensitive to the gradual changes in abilities with aging. Rather than the amount of experience in using technology, age was the stronger predictor of older adults' performance on the Fitts task. Additionally, compared with the younger groups, the users above 80 years old demonstrated significantly higher behavioral variation during the use of mobile device interfaces.

CONCLUSION

This research confirmed that Fitts' law is applicable to the evaluation of the effects of aging on the use of mobile device interfaces. Adults above the age of 80 years should be a major focus for special individualized interface design. This finding can inform future designers and researchers in the development of individualized interface designs for older adult users to enhance their user experiences of mobile device technology.

RELEVANCE TO INDUSTRY

Future designers and researchers can apply the finding on Fitts' law in this research to develop user-friendly interface designs for mobile technology for older adults and thereby improve their user experiences to enhance their independence and quality of life through the use of technology.

The accuracy of the frontal extent in stereoscopic environments: A comparison of direct selection and virtual cursor techniques

This experiment investigated the accuracy of distance judgment and perception of the frontal extent in a stereoscopic environment. Eight virtual targets were projected in a circular arrangement with two center-to-center target distances (18 cm and 36 cm) and three target sizes (0.6 cm, 1.5 cm, and 3.7 cm). Fourteen participants judged the positions of virtual targets presented at a distance of 90 cm from them by employing two different interaction techniques: the direct selection technique and the virtual cursor technique. The results showed overall higher accuracy with the virtual cursor technique than with the direct selection technique. It was also found that the target size significantly affected the frontal extent accuracy. In addition, significant interactions between technique and center-to-center target distance were observed. The direct selection technique was more accurate at the 18 cm center-to-center target distance along the horizontal (x) and vertical (y) axes, while the virtual cursor technique was more accurate for the 36 cm center-to-center target distance along the y axis. During the direct selection, estimations tended to converge to the center of the virtual space; however, this convergence was not observed in the virtual cursor condition. The accuracy of pointing estimations suffered on the left side of participants. These findings could provide direction for virtual reality developers in selecting proper interaction techniques and appropriately positioning virtual targets in stereoscopic environments.

Extraction of the ^{235}U and ^{239}Pu Antineutrino Spectra at Daya Bay

This Letter reports the first extraction of individual antineutrino spectra from ^{235}U and ^{239}Pu fission and an improved measurement of the prompt energy spectrum of reactor antineutrinos at Daya Bay. The analysis uses 3.5×10^{6} inverse beta-decay candidates in four near antineutrino detectors in 1958 days. The individual antineutrino spectra of the two dominant isotopes, ^{235}U and ^{239}Pu, are extracted using the evolution of the prompt spectrum as a function of the isotope fission fractions. In the energy window of 4-6 MeV, a 7% (9%) excess of events is observed for the ^{235}U (^{239}Pu) spectrum compared with the normalized Huber-Mueller model prediction. The significance of discrepancy is 4.0σ for ^{235}U spectral shape compared with the Huber-Mueller model prediction. The shape of the measured inverse beta-decay prompt energy spectrum disagrees with the prediction of the Huber-Mueller model at 5.3σ. In the energy range of 4-6 MeV, a maximal local discrepancy of 6.3σ is observed.

Impact of parallax and interpupillary distance on size judgment performances of virtual objects in stereoscopic displays

Effective interactions in both real and stereoscopic environments require accurate perceptions of size and position. This study investigated the effects of parallax and interpupillary distance (IPD) on size perception of virtual objects in widescreen stereoscopic environments. Twelve participants viewed virtual spherical targets displayed at seven different depth positions, based on seven parallax levels. A perceptual matching task using five circular plates of different sizes was used to report the size judgment. The results indicated that the virtual objects were perceived as larger and smaller than the corresponding theoretical sizes, respectively, in negative and positive parallaxes. Similarly, the estimates from participants with small IPDs were greater than the predicted estimates. The findings of this study are used to explain human factor issues such as the phenomenon of inaccurate depth judgments in virtual environments, where compression is widely reported, especially at farther egocentric distances. Furthermore, a multiple regression model was developed to describe how the size was affected by parallax and IPD. Practitioner Summary: The study investigates the effects of parallax and interpupillary distance on size perception of virtual targets in a stereoscopic environment. Virtual objects were perceived as larger in negative and smaller in positive parallax. Also, size estimates were greater than the theoretical sizes for participants with smaller IPD. A multiple-regression model explains the impact of parallax and measured IPD. Abbreviations IPD interpupillary distance VR virtual eality HMD head mounted-displays 2AFC two-alternative forced choice IOD interocular distance PD pupillary distance ANOVA analysis of variance.

Measurement of the Electron Antineutrino Oscillation with 1958 Days of Operation at Daya Bay

We report a measurement of electron antineutrino oscillation from the Daya Bay Reactor Neutrino Experiment with nearly 4 million reactor ν[over ¯]_{e} inverse β decay candidates observed over 1958 days of data collection. The installation of a flash analog-to-digital converter readout system and a special calibration campaign using different source enclosures reduce uncertainties in the absolute energy calibration to less than 0.5% for visible energies larger than 2 MeV. The uncertainty in the cosmogenic ^{9}Li and ^{8}He background is reduced from 45% to 30% in the near detectors. A detailed investigation of the spent nuclear fuel history improves its uncertainty from 100% to 30%. Analysis of the relative ν[over ¯]_{e} rates and energy spectra among detectors yields sin^{2}2θ_{13}=0.0856±0.0029 and Δm_{32}^{2}=(2.471_{-0.070}^{+0.068})×10^{-3}  eV^{2} assuming the normal hierarchy, and Δm_{32}^{2}=-(2.575_{-0.070}^{+0.068})×10^{-3}  eV^{2} assuming the inverted hierarchy.

Eye Movement Parameters for Performance Evaluation in Projection-based Stereoscopic Display

The current study applied Structural Equation Modeling (SEM) to analyze the rela-tionship among index of difficulty (ID) and parallax on eye gaze movement time (EMT), fixation duration (FD), time to first fixation (TFF), number of fixation (NF), and eye gaze accuracy (AC) simultaneously. EMT, FD, TFF, NF, and AC were measured in the projec-tion-based stereoscopic display by utilizing Tobii eye tracker system. Ten participants were recruited to perform multi-directional tapping task using within-subject design with three different levels of parallax and six different levels of ID. SEM proved that ID had significant direct effects on EMT, NF, and FD also a significant indirect effect on NF. However, ID was found not a strong predictor for AC. SEM also proved that parallax had significant direct effects on EMT, NF, FD, TFF, and AC. Apart from the direct effect, parallax also had significant indirect effects on NF and AC. Regarding the interrelation-ship among dependent variables, there were significant indirect effects of FD and TFF on AC. Our results concluded that higher AC was achieved by lowering parallax (at the screen), longer EMT, higher NF, longer FD, and longer TFF. Practitioner Summary: The SEM could provide valuable theoretical foundations of the interrelationship among eye movement parameters for VR researchers and human-virtual-reality interface developers especially for predicting eye gaze accuracy.

The effect of parallax on eye fixation parameter in projection-based stereoscopic displays

The promising technology of stereoscopic displays is interesting to explore because 3D virtual applications are widely known. Thus, this study investigated the effect of parallax on eye fixation in stereoscopic displays. The experiment was conducted in three different levels of parallax, in which virtual balls were projected at the screen, at 20 cm and 50 cm in front the screen. The two important findings of this study are that parallax has significant effects on fixation duration, time to first fixation, number of fixations, and accuracy. The participant had more accurate fixations, fewer fixations, shorter fixation durations, and shorter times to first fixation when the virtual ball was projected at the screen than when it was projected at the other two levels of parallax.

Kinematic analysis of direct pointing in projection-based stereoscopic environments

This work investigated the effects of visual information, parallax, and target positions on movement performances in projection-based stereoscopic displays (PSDs). Fifteen (26.5 ± 3.83 years) self-declared right-handed individuals, with normal or corrected to normal visual acuity, completed pointing tasks in stereoscopic and real environments (RE). Three-dimensional spatial data, recorded by a motion system composed of six infrared cameras, was used to compute kinematics of reaching a real/virtual object at a combination of three parallax and nine frontal planar positions. The results indicated that movement in the PSD was slower and needed longer confirmation time than that in the RE. This might be because of the difficulty and misperception of distance associated with PSD. The motions were initiated faster but took longer to complete in vision-based conditions. The overall kinematic parameters were better as targets were presented closer to participants and around the center of displays. However, during pointing at a target that was continuously visible or presented briefly and disappeared, participants applied similar movement strategies to approach the visual objects. The comparable kinematics and movement behaviors in stereoscopic displays encourage the use of direct pointing that would enhance reaching and grasping tasks - which are important in applications such as rehabilitation, surgical training, and other programs that employ upper limbs. In addition, the more natural interaction by direct pointing minimizes the effort of learning new skills to use other devices.

Single Crystal Growth and Spin Polarization Measurements of Diluted Magnetic Semiconductor (BaK)(ZnMn)2As2

Recently a new diluted magnetic semiconductor, (Ba,K)(Zn,Mn)2As2 (BZA), with high Curie temperature was discovered, showing an independent spin and charge-doping mechanism. This makes BZA a promising material for spintronics devices. We report the successful growth of a BZA single crystal for the first time in this study. An Andreev reflection junction, which can be used to evaluate spin polarization, was fabricated based on the BZA single crystal. A 66% spin polarization of the BZA single crystal was obtained by Andreev reflection spectroscopy analysis.

Is the Dispersion Relation Applicable for Exotic Nuclear Systems? The Abnormal Threshold Anomaly in the ^{6}He+^{209}Bi System

The threshold anomaly of the phenomenological potential has been known for a long time in nuclear reactions at energies around the Coulomb barrier, where the connection between the real and imaginary potentials is well described by the dispersion relation. However, this connection is not clear yet for some weakly bound nuclear systems, especially for reactions induced by exotic radioactive nuclei. In this study, precise optical potentials of the halo nuclear system ^{6}He+^{209}Bi were extracted via ^{208}Pb(^{7}Li,^{6}He) transfer reactions with energies measured downward to the extremely sub-barrier region. The real potential presents a bell-like shape around the barrier as a normal threshold anomaly in tightly bound nuclear systems. However, the imaginary potential shows an abnormal behavior: it increases first with energy decreasing below the barrier and then falls quickly down to 0. It is the first time the threshold of the imaginary potential has been determined in an exotic nuclear system. Moreover, experimental results show the dispersion relation is not applicable for this system, which may be a common phenomenon for exotic nuclear systems. We discuss possible explanations for such a peculiar behavior, but further study is still desired for the underlying physics.

Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay

The Daya Bay experiment has observed correlations between reactor core fuel evolution and changes in the reactor antineutrino flux and energy spectrum. Four antineutrino detectors in two experimental halls were used to identify 2.2 million inverse beta decays (IBDs) over 1230 days spanning multiple fuel cycles for each of six 2.9 GW_{th} reactor cores at the Daya Bay and Ling Ao nuclear power plants. Using detector data spanning effective ^{239}Pu fission fractions F_{239} from 0.25 to 0.35, Daya Bay measures an average IBD yield σ[over ¯]_{f} of (5.90±0.13)×10^{-43}  cm^{2}/fission and a fuel-dependent variation in the IBD yield, dσ_{f}/dF_{239}, of (-1.86±0.18)×10^{-43}  cm^{2}/fission. This observation rejects the hypothesis of a constant antineutrino flux as a function of the ^{239}Pu fission fraction at 10 standard deviations. The variation in IBD yield is found to be energy dependent, rejecting the hypothesis of a constant antineutrino energy spectrum at 5.1 standard deviations. While measurements of the evolution in the IBD spectrum show general agreement with predictions from recent reactor models, the measured evolution in total IBD yield disagrees with recent predictions at 3.1σ. This discrepancy indicates that an overall deficit in the measured flux with respect to predictions does not result from equal fractional deficits from the primary fission isotopes ^{235}U, ^{239}Pu, ^{238}U, and ^{241}Pu. Based on measured IBD yield variations, yields of (6.17±0.17) and (4.27±0.26)×10^{-43}  cm^{2}/fission have been determined for the two dominant fission parent isotopes ^{235}U and ^{239}Pu. A 7.8% discrepancy between the observed and predicted ^{235}U yields suggests that this isotope may be the primary contributor to the reactor antineutrino anomaly.

Training Performance of Laparoscopic Surgery in Two- and Three-Dimensional Displays

INTRODUCTION

This research investigated differences in the effects of a state-of-art stereoscopic 3-dimensional (3D) display and a traditional 2-dimensional (2D) display in simulated laparoscopic surgery over a longer duration than in previous publications and studied the learning effects of the 2 display systems on novices.

METHODS

A randomized experiment with 2 factors, image dimensions and image sequence, was conducted to investigate differences in the mean movement time, the mean error frequency, NASA-TLX cognitive workload, and visual fatigue in pegboard and circle-tracing tasks.

RESULTS

The stereoscopic 3D display had advantages in mean movement time ( P < .001 and P = .002) and mean error frequency ( P = .010 and P = .008) in both the tasks. There were no significant differences in the objective visual fatigue ( P = .729 and P = .422) and in the NASA-TLX ( P = .605 and P = .937) cognitive workload between the 3D and the 2D displays on both the tasks. For the learning effect, participants who used the stereoscopic 3D display first had shorter mean movement time in the 2D display environment on both the pegboard ( P = .011) and the circle-tracing ( P = .017) tasks.

CONCLUSIONS

The results of this research suggest that a stereoscopic system would not result in higher objective visual fatigue and cognitive workload than a 2D system, and it might reduce the performance time and increase the precision of surgical operations. In addition, learning efficiency of the stereoscopic system on the novices in this study demonstrated its value for training and education in laparoscopic surgery.

Eye Pointing in Stereoscopic Displays

This study investigated eye pointing in stereoscopic displays. Ten participants performed 18 tapping tasks in stereoscopic displays with three different levels of parallax (at the screen, 20 cm and 50 cm in front of the screen). The results showed that parallax had significant effects on hand movement time, eye movement time, index of performance in hand click and eye gaze. The movement time was shorter and the performance was better when the target was at the screen, compared to the conditions when the targets were seen at 20 cm and 50 cm in front of the screen. Furthermore, the findings of this study supports that the eye movement in stereoscopic displays follows the Fitts’ law. The proposed algorithm was effective on the eye gaze selection to improve the good fit of eye movement in stereoscopic displays.

Verbal and Cognitive Distractors in Driving Performance While Using Hands-Free Phones

This study investigated the effect of different types of distractions related to use of a hands-free phone on driving performance. The study used three types of verbal distractors: casual conversation, simple arithmetic number guessing, and number adding, in the phone conversation. 12 adults were instructed to follow a lead vehicle on a closed-course highway in a fixed-based driving simulator. The results showed that use of a hands-free cellular phone involving verbal and cognitive distractions impaired driving performance and skill. Types of distraction produced significantly different effects on several dependent variables: the driving speed, headway (distance between the lead car and the manipulated car), brake reaction time, and number of collisions with the lead car. In general, the higher the cognitive load involved in the dialogue, the worse the driving performance.

Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments

Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^{2}2θ_{μe} are set over 6 orders of magnitude in the sterile mass-squared splitting Δm_{41}^{2}. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm_{41}^{2}<0.8  eV^{2} at 95%  CL_{s}.

Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment

This Letter reports an improved search for light sterile neutrino mixing in the electron antineutrino disappearance channel with the full configuration of the Daya Bay Reactor Neutrino Experiment. With an additional 404 days of data collected in eight antineutrino detectors, this search benefits from 3.6 times the statistics available to the previous publication, as well as from improvements in energy calibration and background reduction. A relative comparison of the rate and energy spectrum of reactor antineutrinos in the three experimental halls yields no evidence of sterile neutrino mixing in the 2×10^{-4}≲|Δm_{41}^{2}|≲0.3  eV^{2} mass range. The resulting limits on sin^{2}2θ_{14} are improved by approx imately a factor of 2 over previous results and constitute the most stringent constraints to date in the |Δm_{41}^{2}|≲0.2  eV^{2} region.

Effects of elevation change on mental stress in high-voltage transmission tower construction workers

High-voltage transmission tower construction is a high-risk operation due to the construction site locations, extreme climatic factors, elevated working surfaces, and narrow working space. To comprehensively enhance our understanding of the psychophysiological phenomena of workers in extremely high tower constructions, we carried out a series of field experiments to test and compare three working surface heights in terms of frequency-domain heart rate variability (HRV) measurements. Twelve experienced male workers participated in this experiment. The dependent variables, namely, heart rate (HR), normalized low-frequency power (nLF), normalized high-frequency power (nHF), and LF-to-HF power ratio (LF/HF), were measured with the Polar RS800CX heart rate monitor. The experimental results indicated that the task workload was similar between working surface heights. Tower construction workers perceived an increased level of mental stress as working surface height increased.

Effect of Vibration on Visual Display Terminal Work Performance

Today electronic visual displays have dramatic use in daily life. Reading these visual displays is subject to their vibration. Using a software-simulation of a vibrated environment, the study investigated the effect of vibration on visual performance and fatigue for several numerical display design characteristics including the font size and the number of digits displayed. Both the frequency and magnitude of vibration had significant effects on the reaction time, accuracy, and visual fatigue. 10 graduate students (23–30 years old; M = 25.6), randomly tested in this experiment, were offered about 25 U.S. dollars for their participation. Numbers in vertical presentation were affected more in vertical vibration than those in horizontal presentation. Analysis showed whenever the display is used in vibration environment, an increased font size may be an effective way to compensate the adverse effect of vibration. The software design of displayed materials must be designed to take the motion effect into consideration to increase the quality of the screen display.

The effects of gardening on quality of life in people with stroke

BACKGROUND

Compared with traditional rehabilitation, gardening has been viewed as a more occupation-based intervention to help patients improve functional performance. However, there is still a need for evidence-based research into what factors interact to create the beneficial effects of gardening for people who have sustained a cerebral vascular accident (CVA).

OBJECTIVE

To explore how plant, gender, and the time after stroke onset influenced improvements in the quality of life of patients in a gardening program.

METHODS

One treatment of tending short-term plants, and another treatment of tending long-term plants were compared. Quality of life improvement was evaluated according to three factors: plant, gender, and the time after stroke onset. The data were analyzed with 2k replicated factorial designs.

RESULTS

The 2k factorial design with replication indicated significant effects on both the social role and the family role. For the social role, the interaction of plant and gender difference was significant. For the family role, the significant effects were found on interaction of plant with both gender and the time after stroke onset.

CONCLUSIONS

Tending plants with different life cycles has varied effects on the quality of life of people who have sustained a CVA. Factors related to gender and the time after stroke onset influenced role competency in this sample.

Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay

This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18)  cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43)  cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) relative to the flux predicted with the Huber-Mueller (ILL-Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.

New measurement of antineutrino oscillation with the full detector configuration at Daya Bay

We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9×10^{5} GW_{th}  ton days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six ^{241}Am-^{13}C radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of sin^{2}2θ_{13} and |Δm_{ee}^{2}| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin^{2}2θ_{13}=0.084±0.005 and |Δm_{ee}^{2}|=(2.42±0.11)×10^{-3}  eV^{2} in the three-neutrino framework.

The postural and control-display gain effects of distal pointing on upper extremity fatigue

Pointing at displays from a distance is becoming common in both work and domestic environments. Ray-casting interaction is easy for novices to learn and understand, but this technique can cause physiological fatigue. To address this issue, the present study aims to investigate the issue of fatigue caused by joint-based pointing methods and Control-Display gains (CD gains) via Fitts' task. Ten healthy subjects participated in the experiment and performed multi-directional tapping tests with three joint-based pointing methods and three CD gains. The experimental results indicated that the joint-based pointing methods indeed affected the physiological and subjective fatigue of the upper limb muscles and measured body parts during distal pointing tasks. The wrist-based pointing method, which can induce substantially lower physiological and subjective fatigue, appears to be superior to the other two methods. There were no significant main effects of CD gains on either physiological fatigue or subjective Borg's CR-10 rating.

PRACTITIONER SUMMARY

The present study investigates the issue of fatigue caused by joint-based pointing methods and CD gains via Fitts’ task. The pointing methods affected the physiological and subjective fatigue of the upper-limb muscles. There were no significant main effects of CD gains on either physiological fatigue or subjective Borg’s CR-10 rating.

B-type natriuretic peptide and cirrhosis progression

Brain natriuretic peptide (BNP) is used as a marker of cardiac dysfunction to predict heart failure mortality. The significance of the prognostic ability of BNP for liver cirrhosis remains unknown, although the levels of BNP seen in cirrhosis are high. We aimed to determine whether the BNP level is related to the stage of cirrhosis and could serve as a prognostic marker of cirrhosis (predict the 1-year all-cause mortality). We recruited 92 patients at different stages of cirrhosis and 81 controls matched by age and gender for this study. At admission, cardiac physical examination and BNP measurements were performed. Upon discharge, the 89 patients were followed up for 12 months. The median BNP levels of patients with cirrhosis were 167.0 pg/mL, which were significantly higher than those of the control group (167.0 vs 34.8 pg/mL, P = 0.001). Serum BNP levels were positively correlated with the Child score, the grade of esophageal varices, a history of spontaneous bacterial peritonitis, and the presence of ascites and collateral circulation. BNP levels above the median were associated with an increased occurrence of death within 12 months of discharge (log rank P = 0.025), as determined by univariate and multivariate Cox regression analyses. Esophageal varices, large/medium volume ascites, and BNP levels were related to the clinical outcome (P = 0.034, 0.030, and 0.025, respectively). Together, these results suggested that serum BNP levels are significantly correlated with the stage of cirrhosis, suggesting that BNP levels might serve as a significant predictor for 1-year all-cause mortality.

An investigation of pointing postures in a 3D stereoscopic environment

Many object pointing and selecting techniques for large screens have been proposed in the literature. There is a lack of quantitative evidence suggesting proper pointing postures for interacting with stereoscopic targets in immersive virtual environments. The objective of this study was to explore users' performances and experiences of using different postures while interacting with 3D targets remotely in an immersive stereoscopic environment. Two postures, hand-directed and gaze-directed pointing methods, were compared in order to investigate the postural influences. Two stereo parallaxes, negative and positive parallaxes, were compared for exploring how target depth variances would impact users' performances and experiences. Fifteen participants were recruited to perform two interactive tasks, tapping and tracking tasks, to simulate interaction behaviors in the stereoscopic environment. Hand-directed pointing is suggested for both tapping and tracking tasks due to its significantly better overall performance, less muscle fatigue, and better usability. However, a gaze-directed posture is probably a better alternative than hand-directed pointing for tasks with high accuracy requirements in home-in phases. Additionally, it is easier for users to interact with targets with negative parallax than with targets with positive parallax. Based on the findings of this research, future applications involving different pointing techniques should consider both pointing performances and postural effects as a result of pointing task precision requirements and potential postural fatigue.

Search for a light sterile neutrino at Daya Bay

A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.

Establishment of a novel, eco-friendly transgenic pig model using porcine pancreatic amylase promoter-driven fungal cellulase transgenes

Competition between humans and livestock for cereal and legume grains makes it challenging to provide economical feeds to livestock animals. Recent increases in corn and soybean prices have had a significant impact on the cost of feed for pig producers. The utilization of byproducts and alternative ingredients in pig diets has the potential to reduce feed costs. Moreover, unlike ruminants, pigs have limited ability to utilize diets with high fiber content because they lack endogenous enzymes capable of breaking down nonstarch polysaccharides into simple sugars. Here, we investigated the feasibility of a transgenic strategy in which expression of the fungal cellulase transgene was driven by the porcine pancreatic amylase promoter in pigs. A 2,488 bp 5'-flanking region of the porcine pancreatic amylase gene was cloned by the genomic walking technique, and its structural features were characterized. Using GFP as a reporter, we found that this region contained promoter activity and had the potential to control heterologous gene expression. Transgenic pigs were generated by pronuclear microinjection. Founders and offspring were identified by PCR and Southern blot analyses. Cellulase mRNA and protein showed tissue-specific expression in the pancreas of F1 generation pigs. Cellulolytic enzyme activity was also identified in the pancreas of transgenic pigs. These results demonstrated the establishment of a tissue-specific promoter of the porcine pancreatic amylase gene. Transgenic pigs expressing exogenous cellulase may represent a way to increase the intake of low-cost, fiber-rich feeds.

Radiation doses of cerebral blood volume measurements using C-arm CT: A phantom study

BACKGROUND AND PURPOSE

Parenchymal blood volume measurement by C-arm CT facilitates in-room peritherapeutic perfusion evaluation. However, the radiation dose remains a major concern. This study aimed to compare the radiation dose of parenchymal blood volume measurement using C-arm CT with that of conventional CTP using multidetector CT.

MATERIALS AND METHODS

A biplane DSA equipped with C-arm CT and a Rando-Alderson phantom were used. Slab parenchymal blood volume (8-cm scanning range in a craniocaudal direction) and whole-brain parenchymal blood volume with identical scanning parameters, except for scanning ranges, were undertaken on DSA. Eighty thermoluminescent dosimeters were embedded into 22 organ sites of the phantom. We followed the guidelines of the International Commission on Radiation Protection number 103 to calculate the effective doses. For comparison, 8-cm CTP with the same phantom and thermoluminescent dosimeter distribution was performed on a multidetector CT. Two repeat dose experiments with the same scanning parameters and phantom and thermoluminescent dosimeter settings were conducted.

RESULTS

Brain-equivalent dose in slab parenchymal blood volume, whole-brain parenchymal blood volume, and CTP were 52.29 ± 35.31, 107.51 ± 31.20, and 163.55 ± 89.45 mSv, respectively. Variations in the measurement of an equivalent dose for the lens were highest in slab parenchymal blood volume (64.5%), followed by CTP (54.6%) and whole-brain parenchymal blood volume (29.0%). The effective doses of slab parenchymal blood volume, whole-brain parenchymal blood volume, and CTP were 0.87 ± 0.55, 3.91 ± 0.78, and 2.77 ± 1.59 mSv, respectively.

CONCLUSIONS

The dose measurement conducted in the current study was reliable and reproducible. The effective dose of slab parenchymal blood volume is about one-third that of CTP. With the advantages of on-site and immediate imaging availability and saving procedural time and patient transportation, slab parenchymal blood volume measurement using C-arm CT can be recommended for clinical application.

Evaluating camouflage design using eye movement data

This study investigates the characteristics of eye movements during a camouflaged target search task. Camouflaged targets were randomly presented on two natural landscapes. The performance of each camouflage design was assessed by target detection hit rate, detection time, number of fixations on display, first saccade amplitude to target, number of fixations on target, fixation duration on target, and subjective ratings of search task difficulty. The results showed that the camouflage patterns could significantly affect the eye-movement behavior, especially first saccade amplitude and fixation duration, and the findings could be used to increase the sensitivity of the camouflage assessment. We hypothesized that the assessment could be made with regard to the differences in detectability and discriminability of the camouflage patterns. These could explain less efficient search behavior in eye movements. Overall, data obtained from eye movements can be used to significantly enhance the interpretation of the effects of different camouflage design.

Modeling movements of a long hand-held tool with effects of moments of inertia

The current experiment aimed to investigate the effects of weight position on movement time in target acquisition tasks. Subsequently, a simple mathematical model was developed to describe the movement time with the moments of inertia. Ten right-handed participants conducted continuous Fitts pointing tasks using a laparoscopic instrument as a long hand-held tool. The results showed significant effects of weight position on movement time. Furthermore, an extended Fitts' law model is proposed for the moments of inertia produced by the hand, instrument, and a constant mass in different positions. This predictive model accounted for 63% of the variance in movement time. The predictive model proposed in the present study can be applied not only to estimate movement time given a particular target width, instrument movement amplitude, and weight position of a long hand-held tool but also to standardize movement time and establish training standards.

Effects of load position and force direction on back muscle loading in one-wheeled wheelbarrow tasks

BACKGROUND

Various parameters related to pushing/pulling tasks have been examined yet the effects of changing the load position in one-wheeled wheelbarrow task has not been examined.

OBJECTIVE

To explore the effects of load position and force direction on muscle activity during wheelbarrow tasks.

PARTICIPANTS

Nine participants were recruited to take part in the experiment.

METHODS

Each participant performed 18 trials consisting of 2 force directions (push and pull) and 9 load positions. The dependent variables were EMG of erector spinae and gripping force. ANOVA was used to identify significant differences between force direction and load position in EMG and gripping force data.

RESULTS

Results showed that peak EMG was lowest for the left and right erector spinae when the load was positioned farther from the participant. Peak EMG of the bilateral erector spinae increased when the weight was near the participant and on the ipsilateral hand.

CONCLUSIONS

Based on the EMG results, we suggest that loads be arranged in the anterior part of the bin in order to reduce muscle activity on the spine during the wheelbarrow task. This finding also provides some directions in the improvement and ergonomic redesign of the one-wheeled wheelbarrow.

Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay

A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9  GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3)  eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.

Developing and evaluating a target-background similarity metric for camouflage detection

BACKGROUND

Measurement of camouflage performance is of fundamental importance for military stealth applications. The goal of camouflage assessment algorithms is to automatically assess the effect of camouflage in agreement with human detection responses. In a previous study, we found that the Universal Image Quality Index (UIQI) correlated well with the psychophysical measures, and it could be a potentially camouflage assessment tool.

METHODOLOGY

In this study, we want to quantify the camouflage similarity index and psychophysical results. We compare several image quality indexes for computational evaluation of camouflage effectiveness, and present the results of an extensive human visual experiment conducted to evaluate the performance of several camouflage assessment algorithms and analyze the strengths and weaknesses of these algorithms.

SIGNIFICANCE

The experimental data demonstrates the effectiveness of the approach, and the correlation coefficient result of the UIQI was higher than those of other methods. This approach was highly correlated with the human target-searching results. It also showed that this method is an objective and effective camouflage performance evaluation method because it considers the human visual system and image structure, which makes it consistent with the subjective evaluation results.