Observable Research Articles

Taming non-analyticities of QFT observables

Many observables in quantum field theories are involved non-analytic functions of the parameters of the theory. However, it is expected that they are not arbitrarily wild, but rather have only a finite amount of geometric complexity. This expectation has been recently formalized by a tameness principle: physical observables should be definable in o-minimal structures and their sharp refinements. In this work, we show that a broad class of non-analytic partition and correlation functions are tame functions in the o-minimal structure known as ℝG — the structure defining Gevrey functions. Using a perturbative approach, we expand the observables in asymptotic series in powers of a small coupling constant. Although these series are often divergent, they can be Borel-resummed in the absence of Stokes phenomena to yield the full partition and correlation functions. We show that this makes them definable in ℝG and provide a number of motivating examples. These include certain 0-dimensional quantum field theories and a set of higher-dimensional quantum field theories that can be analyzed using constructive field theory. Finally, we discuss how the eigenvalues of certain Hamiltonians in quantum mechanics are also definable in ℝG.

Predicting nonequilibrium Green’s function dynamics and photoemission spectra via nonlinear integral operator learning

Abstract Understanding the dynamics of nonequilibrium quantum many-body systems is an important research topic in a wide range of fields across condensed matter physics, quantum optics, and high-energy physics. However, numerical studies of large-scale nonequilibrium phenomena in realistic materials face serious challenges due to intrinsic high-dimensionality of quantum many-body problems and the absence of time-invariance. The nonequilibrium properties of many-body systems can be described by the dynamics of the correlator, or the Green’s function of the system, whose time evolution is given by a high-dimensional system of integro-differential equations, known as the Kadanoff–Baym equations (KBEs). The time-convolution term in KBEs, which needs to be recalculated at each time step, makes it difficult to perform long-time numerical simulation. In this paper, we develop an operator-learning framework based on recurrent neural networks (RNNs) to address this challenge. We utilize RNNs to learn the nonlinear mapping between Green’s functions and convolution integrals in KBEs. By using the learned operators as a surrogate model in the KBE solver, we obtain a general machine-learning scheme for predicting the dynamics of nonequilibrium Green’s functions. Besides significant savings per each time step, the new methodology reduces the temporal computational complexity from O ( N t 3 ) to O ( N t ) where Nt is the number of steps taken in a simulation, thereby making it possible to study large many-body problems which are currently infeasible with conventional KBE solvers. Through various numerical examples, we demonstrate the effectiveness of the operator-learning based approach in providing accurate predictions of physical observables such as the reduced density matrix and time-resolved photoemission spectra. Moreover, our framework exhibits clear numerical convergence and can be easily parallelized, thereby facilitating many possible further developments and applications.

Demise of Kreutz Sungrazing Comet C/2024 S1 (ATLAS)

Abstract Most Kreutz family sungrazing comets are discovered only days before perihelion, severely limiting observational opportunities to study their physical nature and decay. Kreutz sungrazer C/2024 S1 (ATLAS) was discovered a month before reaching its perihelion distance of 0.008 au, allowing physical observations from both ground- and space-based telescopes. We present observations from 0.9 to 0.4 au using the Nordic Optical Telescope showing that (1) nucleus disintegration was ongoing already at 0.7 au pre-perihelion, (2) the activity varied unpredictably with distance, and (3) the nucleus radius was <600 m (red geometric albedo 0.04 assumed). We also use coronagraphic observations from the STEREO-A spacecraft to study C/2024 S1 at heliocentric distances ≲ 0.1 au. We find that the coma scattering cross section peaked near 0.075 au and faded progressively, by a factor ∼20, toward the last observation at 0.02 au. We interpret the near-perihelion fading as a result of the sublimation of refractory coma grains, beginning at blackbody temperatures ∼1000 K, consistent with olivine composition. The comet was not detected after perihelion. We consider processes operating to destroy the nucleus when near perihelion, concluding that rotational instability and sublimation losses work together toward this end, even before entry of the comet into the Roche lobe of the Sun.

Processes in the Kitikmeot Sea estuary constraining marine life

The Kitikmeot Sea, in the south-central Canadian Arctic Archipelago, is an estuarine system comprised of Coronation Gulf, Bathurst Inlet, Dease Strait, and Queen Maud Gulf. It is unique in the pan-Arctic system due to three defining features: (1) shallow bounding straits to the west (Dolphin and Union Strait) and northeast (Victoria Strait) that are less than 30 m deep; (2) Arctic Ocean inflow carrying nutrient and salt supplies over the bounding sills that are primarily delivered from the Canada Basin; and (3) massive freshwater input from the mainland watershed that drains an area almost 5 times larger than the Kitikmeot Sea. Here we present physical and geochemical observations obtained from 1999–2020 to show that these conditions maintain an estuarine circulation year-round, wherein the excess low-salinity water, formed from inflowing rivers and seasonal ice melt, exits over both bounding sills and is replenished by inflowing oceanic waters from Amundsen Gulf and Larsen Sound. The shallow sills both restrict the depth of inflow, dictating the salinity and nutrient concentrations of inflowing waters, and increase tidal speeds over the sills, which leads to mixing between the outflowing and inflowing water that further lowers inflowing salinity and nutrient concentrations. Together, all these processes establish a strongly stratified and overall low-productivity ecosystem within the Kitikmeot Sea. We propose a conceptual model of marine ecosystem function that favors an abundance of Arctic char and seals as top predators instead of the larger polar bears and whales as found adjacent to the Kitikmeot Sea in the Canadian Arctic Archipelago.

Kdotpy: k·p theory on a lattice for simulating semiconductor band structures

The software project kdotpy provides a Python application for simulating electronic band structures of semiconductor devices with k·p theory on a lattice. The application implements the widely used Kane model, capable of reliable predictions of transport and optical properties for a large variety of topological and non-topological materials with a zincblende crystal structure. The application automates the tedious steps of simulating band structures. The user inputs the relevant physical parameters on the command line, for example materials and dimensions of the device, magnetic field, and temperature. The program constructs the appropriate matrix Hamiltonian on a discretized lattice of spatial coordinates and diagonalizes it. The physical observables are extracted from the eigenvalues and eigenvectors and saved as output. The program is highly customizable with a large set of configuration options and material parameters.

Codebase release 1.0 for kdotpy

The software project kdotpy provides a Python application for simulating electronic band structures of semiconductor devices with k·p theory on a lattice. The application implements the widely used Kane model, capable of reliable predictions of transport and optical properties for a large variety of topological and non-topological materials with a zincblende crystal structure. The application automates the tedious steps of simulating band structures. The user inputs the relevant physical parameters on the command line, for example materials and dimensions of the device, magnetic field, and temperature. The program constructs the appropriate matrix Hamiltonian on a discretized lattice of spatial coordinates and diagonalizes it. The physical observables are extracted from the eigenvalues and eigenvectors and saved as output. The program is highly customizable with a large set of configuration options and material parameters.

Machine-Learning-Based Activity Tracking for Individual Pig Monitoring in Experimental Facilities for Improved Animal Welfare in Research

In experimental research, animal welfare should always be of the highest priority. Currently, physical in-person observations are the standard. This is time-consuming, and results are subjective. Video-based machine learning models for monitoring experimental pigs provide a continuous and objective observation method for animal misthriving detection. The aim of this study was to develop and validate a pig tracking technology, using video-based data in a machine learning model to analyze the posture and activity level of experimental pigs living in single-pig pens. A research prototype was created using a microcomputer and a ceiling-mounted camera for live recording based on the obtained images from the experimental facility, and a combined model was created based on the Ultralytics YOLOv8n for object detection trained on the obtained images. As a second step, the Lucas–Kanade sparse optical flow technique for movement detection was applied. The resulting model successfully classified whether individual pigs were lying, standing, or walking. The validation test showed an accuracy of 90.66%, precision of 90.91%, recall of 90.66%, and correlation coefficient of 84.53% compared with observed ground truth. In conclusion, the model demonstrates how machine learning can be used to monitor experimental animals to potentially improve animal welfare.

Development of Run-Balance-Swim-Balance (RBS) exercise model in physical education learning to improve physical literacy: a special study on the biak tribe

Introduction: The low level of physical literacy in Papua province needs to be addressed through physical education in schools. Therefore, this study developed an ethnography-based Run-Balance-Swim (RBS) exercise model for the Biak tribe. Objective: Improving physical literacy of students in Papua through the Run-Balance-Swim (RBS) exercise model. Methodology: A research and development method were used to produce an ethnographically appropriate training model for the Biak tribe. This study involved 100 elementary school students from the Biak tribe, which were divided into small-scale trial groups (n=30 students) and large-scale trials (n=70 students). Data were collected using expert validation instruments (content validation) and physical literacy observation questionnaire and physical literacy knowledge questionnaire (PLKQ) which were filled in by respondents during pretest and posttest. Data were analyzed using the N-Gain Score test to determine the effectiveness of the Run-Balance-Swim (RBS) training model. Results: The results of the small-scale trial were 79.09% (good), after revision in the large-scale trial obtained 88.37% (good) with a validity of 0.781. These findings indicate that the application of the exercise model with an ethnographic approach has a high effectiveness in improving the physical literacy of Biak tribe students with an N-Gain Score value of 0.807 (high) and an N-Gain Percent value = 80.73% (effective). Discussion: The results of this study are similar to previous studies which stated that running, balance training and swimming are effective in improving physical literacy. Conclusions: It is suggested that the Run-Balance-Swim (RBS) training model can be implemented by Physical education teachers in Papua, as an effort to improve physical literacy.

Impact of artificial aging on the physical and mechanical properties of polycaprolactone under the combined effect of UV-radiation and elevated temperatures

ABSTRACT Annotation In this work the effect of long-term UV-radiation and temperature degradation on physical and mechanical properties of PCL was experimentally studied. Artificial aging of PCL at 30, 35 and 40°C and UV irradiation for 166, 360 and 554 h was carried out on a specially designed bench. Microstructure evaluation, spectroscopic studies and tensile tests were performed on aged specimens. On the surface of aged PCL there appear zones of irregular degradation with pronounced detachment of separate polymer fragments. Fragmentation occurs as a result of more intensive photodegradation and oxidative processes. According to the results of FTIR analysis, a strong effect on crystallinity is shown with two-factor exposure to PCL over time. At 30°C, with increasing UV degradation time, the crystallinity of PCL decreases by 7% in 504 hours. It was found that increasing the temperature during aging to 40°C leads to a more intense degradation of the crystalline phase of PCL and a decrease in crystallinity by 10% over the same period. Curves of changes in the mechanical properties of PCL versus aging time were obtained. The Young’s modulus is reduced by 20% from 326 to 252 MPa, the tensile strength is 2 times (from 16.1 to 8.5 MPa), and the relative elongation at break is 5 times compared to the initial PCL, from 528 to 103%. Based on physical observations of the properties of environmentally friendly biodegradable polymers, it is possible to provide controlled representations of their use for packaging and biomedical applications to replace petroleum-based plastics as a structural material.

Optimal Dynamical Gauge in the Quantum Rabi Model

Abstract We investigate the gauge dependence of physical observables in the quantum Rabi model (QRM) under di erent potential fields, arising from the Hilbert-space truncation of the atomic degrees of freedom. In both square-well and harmonic potentials, we find that the optimal gauge for the groundstate energy depends on the cavity frequency: the dipole gauge is optimal in the low-frequency limit, while the Coulomb gauge is optimal in the high-frequency limit. For a dynamical quantity such as the out-of-time-order correlator (OTOC), we demonstrate the necessity of introducing an optimal dynamical gauge. This study provides deeper insights into the intricate relationship between gauge choice and the dynamics of quantum electrodynamics (QED) systems, paving the way for more accurate theoretical frameworks.

Digital inventory audits: an alternative approach to physical observation in audit evidence gathering

PurposeThis study examines whether digital streaming and observation technologies can serve as an alternative approach for collecting inventory audit evidence, the challenges faced in their adoption and the factors contributing to their non-adoption.Design/methodology/approachThis study adopts a two-stage, mixed-method approach, beginning with pilot study interviews that informed the comprehensive survey with qualitative and quantitative data. Quantitative data were analyzed using descriptive statistics, t-tests and Pearson’s correlation coefficient, while qualitative data were analyzed using qualitative content analysis.FindingsOur findings revealed a positive perspective concerning the effectiveness and reliability of these technologies for inventory audits and the efficiency of internal controls within them, despite challenges such as obtaining a holistic view of the warehouse, observing obsolescence, ensuring inventory completeness and general reliability concerns. Additionally, preferences for physical inventory audits and skepticism about these technologies’ potential to enhance audit quality were identified as factors contributing to their non-adoption.Research limitations/implicationsThese findings have important implications for cost-conscious firms because they reveal that carefully adopting intermediate technologies can enhance the audit process. Our findings are relevant to audit regulators and firms interested in determining whether such technologies enhance audit efficiency and quality. This study highlights the need for updated auditing standards and directives and technologies that meet auditing requirements.Originality/valueThis study contributes to the literature by uncovering whether less advanced technologies can be used as an alternative approach to collect audit evidence. Consequently, the finding adds to the growing body of literature underscoring the potential of technologies, even less sophisticated ones, to enhance the efficiency and effectiveness of audits, despite their challenges. Additionally, it underscores the need for clear regulatory standards, suggests that auditors embrace emerging technologies and acquire relevant skills and offers insights for technology developers on audit firms’ concerns regarding digital technologies.

Predicting nonequilibrium Green's function dynamics and photoemission spectra via nonlinear integral operator learning

Abstract Understanding the dynamics of nonequilibrium quantum many-body systems is an important research topic in a wide range of fields across condensed matter physics, quantum optics, and high-energy physics. However, numerical studies of large-scale nonequilibrium phenomena in realistic materials face serious challenges due to intrinsic high-dimensionality of quantum many-body problems and the absence of time-invariance. The nonequilibrium properties of many-body systems can be described by the dynamics of the correlator, or the Green's function of the system, whose time evolution is given by a high-dimensional system of integro-differential equations, known as the Kadanoff-Baym equations (KBEs). The time-convolution term in KBEs, which needs to be recalculated at each time step, makes it difficult to perform long-time numerical simulation. In this paper, we develop an operator-learning framework based on Recurrent Neural Networks (RNNs) to address this challenge.
We utilize RNNs to learn the nonlinear mapping between Green's functions and convolution integrals in KBEs.
By using the learned operators as a surrogate model in the KBE solver, we obtain a general machine-learning scheme for predicting the dynamics of nonequilibrium Green's functions. Besides significant savings per each time step, the new methodology reduces the temporal computational complexity from $O(N_t^3)$ to $O(N_t)$ 
where $N_t$ is the number of steps taken in a simulation, thereby
making it possible to study large many-body problems which are currently infeasible with conventional KBE solvers. 
Through various numerical examples, we demonstrate the effectiveness of the operator-learning based approach in providing accurate predictions of physical observables such as the reduced density matrix and time-resolved photoemission spectra. 
Moreover, our framework exhibits clear numerical convergence and can be easily parallelized, thereby facilitating many possible further developments and applications.

Introductory learning of quantum probability and quantum spin with physical models and observations

Quantum probability and quantum spin are foundational concepts in quantum physics, not normally taught in pre-university education. In line with recent efforts to modernize quantum science education in schools, this paper presents learning sequences designed to provide an introductory conceptual understanding of these core physical concepts. This is achieved by choosing physical models that provide tangible classical representations that can be contrasted with quantum observations relevant to modern science and technology. This approach allows activity-based learning without the use of algebra. The concept of quantum probability is taught through activities with phasor wheels in which quantum probability is obtained graphically and interpreted using single-photon interference data. Quantum spin and spin vectors are taught by contrasting quantum spin with classical spin, explored through activities with gyroscopes and spinning tops. Quantum concepts are evoked by emphasizing how spin is different and how it manifests in real-world technologies such as magnets and MRI imaging. We describe learning sequences developed following the Model of Educational Reconstruction in which historical discoveries are combined with activities based on classical models and relevant quantum applications. We summarize test results from programs conducted with students aged 11–15. Most students connect the models and activities to quantum concepts and retain knowledge of quantum spin six months after the program. The successful learning outcomes indicate that teachers can effectively introduce quantum probability and quantum spin concepts to middle school using learning sequences such as those presented here.

Nurses' Recognition and Care of Thirst in Perioperative Patients in Japan.

Postoperative thirst is common and distressing to patients, as is pain and nausea. The causes of postoperative thirst are complex and include factors like preoperative fasting, perioperative fluid loss, and certain anesthesia medications. Effective care for postoperative thirst has been shown in post-anesthesia care units (PACUs), but many Japanese hospitals lack PACUs or do not address thirst in their PACUs. Therefore, cooperation between the operating room and ward nurses is crucial for providing proper care for postoperative thirst. The purpose of this study was to clarify the actual situation of ward nurses' and operating room nurses' recognition and care of thirst in postoperative patients. The study was a cross-sectional survey conducted using a self-administered questionnaire based on previous research. Study participants were nurses working in surgical wards and operating rooms of two university-affiliated hospitals. The survey items included (1) participants' characteristics, (2) recognition of thirst in perioperative patients, and (3) actual care provided to perioperative patients for thirst. Data were collected between September and October 2022 and subjected to descriptive and bivariate analysis. A total of 298 ward nurses and 43 operating room nurses were included in the study. Among the observation items, thirst was observed least frequently. Both ward nurses and operating room nurses recognized patient thirst based on complaints rather than physical observations. Sharing of information about patient thirst differed between ward nurses and operating room nurses. None of the participants used scales or scores to evaluate thirst. The most common postoperative care in the ward was "They were asked to do a mouthwash with water," while in the operating room, it was "Placed a moistened gauze against the mouth." The reasons for selecting a particular type of care were primarily based on "Because of the patient's wishes" and "I think it is effective," while the reasons for not providing care included "Because there is an instruction not to drink water," "Due to the possibility of aspiration," "I don't have the knowledge and don't know how," and "I'm busy with other work." Regarding the recognition of thirst, both ward nurses and operating room nurses recognized patient thirst most often when the patient directly reported feeling thirsty. They relied more on patients' verbal complaints than physical observations to recognize thirst. Both surgical ward nurses and operating room nurses provided care based on their experience.

Spatiotemporal variation in population size and relative abundance of Kalij pheasant (Lophura leucomelanos) in scrub forest.

Most species of pheasants (Galliformes: Phasianidae) occur in Asia. In Pakistan, pheasants occur from 245-3050 m in altitude, and one of these, the Kalij pheasant (Lophura leucomelanos) is a large-bodied, brightly-colored habitat quality indicator species. The present study was designed to determine spatiotemporal variation, population size, and the relative abundance of Kalij pheasants in Haripur, Pakistan. The line transects and point count methods were used to collect direct (physical observations) and indirect signs (feathers and calls) to avoid double counting. Twenty field surveys were conducted along 16 transects with an area of 0.811 km2 in 4 study sites to quantify habitat utilization of Kalij pheasant. Kalij pheasant activities were observed at the start of dawn (0600 hours to 0730 hours) and ended by 1630 hours to 1800 hours dusk period with only a few sightings during the middle of the day. Study sites were selected based on confirmation of presence signs. Twenty-seven individuals with direct (16) and indirect (feather = 5, calls = 6) signs were encountered while walking along line transects. Twelve signs were counted (sightings = 3, Calls = 9) within the radius of 11-50 m in the point count method. Results showed that the Kalij pheasant occupied scrub forest with dense vegetation between 500-1100m away. The mean encounter rate of the Kalij pheasant was 0.82/km, which was higher from July to September. The sex ratio (1.17) is biased toward males in the overall population of Kalij pheasants. The estimated mean density of the Kalij pheasant in Haripur was 6.97 animals/km2, and the total abundance was 142 individuals. New potential sites may be identified and declared as protected areas, and awareness and support of the local community are recommended for the protection and management of the Kalij pheasant.

Pengaruh Penambahan Bubuk Cengkeh (Syzygium aromaticum) Sebagai Pengawet Alami Terhadap Daya Simpan Selai Cempedak (Artocarpus campeden)

This study aims to determine the effect of clove powder on the shelf life of day 1 and day 5, pH levels, water content, and sensory testing of cempedak jam. This study used (CRD) with 4 formulations with different concentrations of clove powder. The formulations were P0 (0% clove powder), P1 (0.2% clove powder), P2 (0.4% clove powder), and P3 (0.6% clove powder). This study used four kinds of analysis consisting of a five-day shelf-life physical observation test, pH, moisture content, and sensory test. Sensory test analysis was carried out on samples of cempedak jam on day 0, but for physical observation analysis, pH, and water content were carried out on cempedak jam with storage on day 1 and day 5. Data analysis on pH and moisture content using One-Way ANOVA statistics was followed by the Tukey test and the sensory test using the Kruskal-Wallis statistic followed by a hypothesis test with a summary test. The use of clove powder can affect the shelf life, more the concentration of clove powder in cempedak jam, the longer shelf life of the jam. The more concentration of clove powder, the acidity (pH) and water content will increase. The sensory test results showed that the concentration of clove powder affected the parameters of color, taste and aroma of cempedak jam.

Beyond Energy: Teleporting Current, Charge, and More

Abstract As an homage to Quantum Energy Teleportation, we generalize the idea to arbitrary physical observables, not limited to energy, and prove a rigorous upper bound on the activated (“teleported”) quantity. The essence of this protocol is a quantum feedback control applied to an entangled ground state of a quantum many-body system. To illustrate the concept, we investigate a (1+1)-dimensional Dirac system and apply feedback control based on fermion chirality to activate electric current and charge. One of the most significant results is the creation of long-range correlations across the system after applying control operations only to one local site. Consequently but surprisingly, the induced charge susceptibility fully reconstructs the phase diagram, despite the model initially having no charge. Moreover, we find an activation of novel chiral dynamics induced by feedback control operations, which can be experimentally confirmed using trapped ions and neutral atoms.

Improving Students' Physical Literacy Through an Active Learning Approach in Elementary Schools

Improving physical literacy among elementary school students is a key focus in shaping an active and healthy generation. Physical literacy encompasses the understanding, skills, and motivation to participate in physical activity throughout life. In the context of elementary education, active learning approaches are considered effective for enhancing physical literacy, as this method encourages more dynamic student engagement in the learning process. This study focuses on elementary school students and how active learning approaches are implemented to improve their physical literacy. The aim of this research is to evaluate the effectiveness of active learning approaches in enhancing physical literacy among elementary school students. This study employs a quantitative method with a quasi-experimental approach. The sample consists of 120 students divided into experimental and control groups. Data were collected through physical literacy tests and observations of student activities during the learning process. The findings indicate that students participating in active learning showed significant improvement in physical literacy compared to the control group. This improvement was evident in motor skills, understanding of physical activity concepts, and student motivation to engage in physical activities. The active learning approach proves effective in enhancing physical literacy among elementary school students. Recommendations are provided for educators to integrate this approach into physical education curricula to improve learning quality and encourage active student participation.

Quantum Reference Frames, Measurement Schemes and the Type of Local Algebras in Quantum Field Theory

We develop an operational framework, combining relativistic quantum measurement theory with quantum reference frames (QRFs), in which local measurements of a quantum field on a background with symmetries are performed relative to a QRF. This yields a joint algebra of quantum-field and reference-frame observables that is invariant under the natural action of the group of spacetime isometries. For the appropriate class of quantum reference frames, this algebra is parameterised in terms of crossed products. Provided that the quantum field has good thermal properties (expressed by the existence of a KMS state at some nonzero temperature), one can use modular theory to show that the invariant algebra admits a semifinite trace. If furthermore the quantum reference frame has good thermal behaviour (expressed in terms of the properties of a KMS weight) at the same temperature, this trace is finite. We give precise conditions for the invariant algebra of physical observables to be a type II1 factor. Our results build upon recent work of Chandrasekaran et al. (J High Energy Phys 2023(2): 1–56, 2023. arXiv:2206.10780), providing both a significant mathematical generalisation of these findings and a refined operational understanding of their model.

The limited clinical utility of a routine creatine kinase (CK) on admission to a psychiatric inpatient unit

BackgroundCreatine kinase (CK) is an intracellular enzyme expressed most commonly in tissues such as skeletal muscle. CK can be used as an investigation to support the diagnosis of conditions such as neuroleptic malignant syndrome (NMS), a rare idiosyncratic drug reaction – classically to antipsychotic medications – which can be fatal. Routine screening of CK in psychiatric inpatients is a known practice, but its value is uncertain. We aimed to ascertain whether such screening resulted in new diagnoses of NMS or other conditions, and changes in clinical management.MethodsUsing an electronic case register, we conducted a descriptive retrospective cohort study, identifying all psychiatric inpatient admissions in a South London mental health trust over a four-year period where a CK test was conducted within 48 h of admission. We extracted the demographic and clinical characteristics (e.g., diagnosis) of those who met inclusion criteria. Free-text review was performed on all those with a CK potentially suggestive of NMS (CK ≥ 4x upper limit of normal reference range (ULN)) to determine the impact of this abnormal result on subsequent management and diagnosis (including NMS if identified).ResultsOf 14,236 inpatient episodes in the specified window, 2358 (16.6%) had a CK test within 48 h of admission. This was ≥ 4x ULN in 327 (13.8%) cases (free-text successfully reviewed in 318). There were no cases of NMS identified. An abnormal CK result led to a new alternative diagnosis, such as dehydration or catatonia, in only 14 patients (4.4% raised CK sample, 0.6% total CK sample). Impact on subsequent management appeared limited, with the most common adjustment being an increase in frequency of physical observations in 47 instances (14.8%).ConclusionsThe clinical utility of untargeted screening using a serum CK for psychiatric inpatients appears limited, with poor specificity in detection of NMS and a minimal impact on subsequent clinical management.