Low Threshold Research Articles

Analysis for [formula omitted] in nonrelativistic quark model

The discovery of the doubly charmed tetraquark Tcc(ūd̄cc) provides a strong constraint on its binding energy compared to its lowest threshold. Using a fully convergent spatial wave function, we simultaneously fit to both the mesons and baryons. Our results indicate that a Yukawa type hyperfine potential produces to a slightly bound state for Tcc with (I,S)=(0,1), placing it below its lowest threshold, which is consistent with the experimental observations. Additionally, our study suggests that Tcc is very likely to be in a compact configuration. This original work is described in Noh and Park (2023).

Stable random laser of perovskite quantum dots based on SiO2-QDs-SiO2 composite nanostructure

In recent years, metal halide perovskite has gradually become a hotspot in the field of optoelectronics. However, the inherent instability of CsPbX3 quantum dots (QDs) seriously affects the amplified spontaneous emission (ASE) or lasing performance. Herein, the highly stable CsPbBr3 random laser is realized in SiO2-QDs-SiO2 (SQS) composite nanostructure doped with Ag nanoislands. The strong scattering generated by SQS composite nanostructure and the localized surface plasmon resonance (LSPR) of metal silver nanoislands provide optical feedback for the formation of random laser. Then a coherent random laser with low threshold (∼2.2 mJ/cm2) is obtained. SiO2 microspheres anchor QDs to avoid photoinduced regeneration and fluorescence quenching caused by QDs clusters. The inner QDs of SQS are effectively protected from water erosion, thus resulting that the samples have higher water resistance. The luminescence intensity still maintains 70 % of the original intensity after 40 days with the addition of pure water. Our research provides an effective method for improving the water stability of perovskite QDs. The highly stable random laser based on perovskite quantum dot film has a wide application prospect in integrated optoelectronics, display imaging and sensing measurement.

Never stop or never start? Optimal stopping under a mixture of CPT and EUT preferences

We consider the problem of finding the best time to stop a diffusion process for an agent with a preference model that is a mixture of expected utility theory (EUT) and cumulative prospect theory (CPT). In view of time-inconsistency, we consider two types of agents: a naive agent, who is not aware of the time-inconsistency and thus re-plans at every instant, and a sophisticated agent, who is aware of the time-inconsistency and takes a so-called intra-personal equilibrium strategy by correctly anticipating her actions in the future. We show that under a wide range of the CPT preference parameter values, the naive agent will never stop. For a sophisticated agent, we use a different notion of intra-personal equilibrium from the one employed by Ebert and Strack (2018). We show that any two-threshold strategy, which is to stop when the diffusion process reaches either an upper threshold or a lower threshold, cannot be an intra-personal equilibrium if the agent overweights worst, unlikely outcomes disproportionally. We derive a sufficient and necessary condition for the strategy of stopping everywhere to be an intra-personal equilibrium and show that this condition does not hold and thus the sophisticated agent may choose to start the diffusion process for some commonly used probability weighting functions.

The Natural Course of Newborns with Transient Congenital Hypothyroidism.

The incidence of congenital hypothyroidism (CH) has increased worldwide over the last decades mainly due to the lowering of screening thresholds, resulting in an increased identification of newborns with transient CH. Several studies reported the prevalence and the predictive parameters of transient CH but reports on the long-term outcome are rare. This study aimed to assess the long-term course of neonates with transient CH. Neonates diagnosed with transient and permanent CH between the years 1998 to 2018 at the Pediatric Endocrine Institute of Ha'Emek Medical Center were enrolled in the study. Data were retrieved retrospectively from medical files. Included in the study were 76 newborns (45M,59%) with transient CH and 53 (25M,47%) with permanent CH. The major cause of transient CH was prematurity (29%) and subclinical hypothyroidism (30%). During retrospective follow-ups of up to 23 years, reinitiation of LT4 therapy was not required apart from four patients with underlying syndromic etiologies. Neurodevelopmental impairment occurred in 16% of children with transient CH compared with 29.4% in the permanent CH group. Transient CH is frequent among preterm infants but is limited to infancy. SCH frequently presents as overt hypothyroidism at birth but in most cases the requirement for LT4 supplemental therapy is limited to the first years of life, suggesting that long-term follow-up of thyroid function tests may be unnecessary for non-syndromic children. The high rate of neurodevelopmental impairment in newborns with transient CH emphasizes the need for neurodevelopmental monitoring in these patients.

Bridging the Technology Gap for Cost‐Effective and Sustainable Treatment of Per‐ and Polyfluoroalkyl Substances in Surface Water and Stormwater

ABSTRACTThis article addresses the urgent need for cost‐effective and sustainable methods to mitigate per‐ and polyfluoroalkyl substances (PFAS) contamination in surface water and stormwater. Although the majority of PFAS research and development to date has focused on groundwater and soil treatment technologies, in some cases there may be a greater risk posed by the high mobility and potential for direct contact with PFAS in surface water and stormwater. Based on the evolving regulatory landscape and the elevated PFAS concentrations observed in available stormwater data near some fire training facilities, additional attention to this topic is needed to support the development of effective and practical treatment technologies for PFAS in surface water and stormwater. We propose addressing the need to bridge the current technology gap between (1) expensive mechanical and/or construction‐intensive technologies and (2) the development of cost‐effective and sustainable surface water and stormwater PFAS treatment options. We envision a future where nature‐based approaches could be employed for stand‐alone PFAS treatment. Alternatively, nature‐based approaches could be used for initial PFAS mass removal as a pretreatment step within a treatment train followed by engineered adsorbents or other technologies, if needed to achieve low concentration cleanup thresholds. We provide an example of a potential nature‐based treatment train that would rely on the natural propensity of PFAS to accumulate in surface water foams using foam‐enhancing weirs and flumes (FWFs), combined with the demonstrated treatment potential of constructed floating wetlands (CFWs). Additional research into the validation, optimization, and site‐specific design factors of nature‐based treatment trains, such as the FWF+CFW approach, warrants future research and development.

Development of Piophila megastigmata (Diptera: Piophilida) at seven constant temperatures

In forensic entomology, the time-related growth and development of carrion insects allows for the estimation of the minimum postmortem interval (PMImin). Piophila megastigmata (Diptera: Piophilidae) is of great significance in estimating PMImin in the late stage of corpse decay. In this paper, the development of P. megastigmata was investigated under the seven constant temperatures of 16–34 °C. The total development time at each temperature was 970.38, 824.50, 593.13, 498.25, 392.00, 385.63 and 405.87 h, respectively. The isomorphen diagram shows the trend of development during different developmental stages at different temperatures. By using a revised linear regression model, the estimated lower lethal developmental thresholds (TL) and thermal summation constant (K) were found to be 10.57 °C and 6936.78 degree hours, respectively. According to a nonlinear model, the TL, upper lethal developmental thresholds (TH), and intrinsic optimum temperature (TΦ) were determined to be 7.53, 34.68, and20.43 °C, respectively. Also, logistic function and an isomegalen diagram were constructed according to the continuous changes in larval body length, and illustrates the time required to develop to a certain length at different temperatures. The obtained results offer crucial fundamental developmental information regarding P. megastigmata, which can be applied in PMImin estimation.

Experimental study of flame morphology in slope buildings under the influence of aspect ratio and ambient wind

Slope structures are commonly used in buildings, but such slope structures can exacerbate the rate of fire spread, complicate building fire safety and suppression, and lead to injuries, deaths, and property damage. Particularly, the thermal hazards posed by ambient wind on sloped fires remain unquantified. In this study, a propane burner was used to simulate the flame morphology behavior of a sloped building fire. 480 tests were conducted with varying aspect ratios (1∼8) of the fire source, different ambient winds (0 m/s∼3.5 m/s), and slope inclination angles (0°∼40°). Results demonstrate that the flame length initially increases and then decreases with an increment in ambient wind velocity. Moreover, with an increased aspect ratio of the fire source (length-to-width ratio), the turning point at which the flame length peaks shift to occur at a lower wind velocity threshold. The tilt angle and height of the flame change (respectively increases and decreases) significantly at lower ambient wind speeds and they tend to asymptotically approach respective constant values. As the ambient wind is further promoted. Existing physical models of flame morphology do not consider the combined effects of fire source aspect ratio, slope inclination angle, and ambient wind. A new slope entrainment restriction factor (EF) was proposed based on an analysis of the upward and leeward entrainment volumes. Using this factor, new models for flame morphology (including flame length, flame tilt angle, and flame height) were established. The accuracy and generalizability of the new flame models have been validated using reference data.

Effect of Four Hemoglobin Transfusion Threshold Strategies in Patients With Acute Myocardial Infarction and Anemia : A Target Trial Emulation Using MINT Trial Data.

The optimal hemoglobin threshold to guide red blood cell (RBC) transfusion for patients with acute myocardial infarction (MI) and anemia is uncertain. To estimate the efficacy of 4 individual hemoglobin thresholds (<10 g/dL [<100 g/L], <9 g/dL [<90 g/L], <8 g/dL [<80 g/L], and <7 g/dL [<70 g/L]) to guide transfusion in patients with acute MI and anemia. Prespecified secondary analysis of the MINT (Myocardial Ischemia and Transfusion) trial using target trial emulation methods. (ClinicalTrials.gov: NCT02981407). 144 clinical sites in 6 countries. 3492 MINT trial participants with acute MI and a hemoglobin level below 10 g/dL. Four transfusion strategies to maintain patients' hemoglobin concentrations at or above thresholds of 10, 9, 8, or 7 g/dL. Protocol exceptions were permitted for specified adverse clinical events. Data from the MINT trial were leveraged to emulate 4 transfusion strategies and estimate per protocol effects on the composite outcome of 30-day death or recurrent MI (death/MI) and 30-day death using inverse probability weighting. The 30-day risk for death/MI was 14.8% (95% CI, 11.8% to 18.4%) for a <10-g/dL strategy, 15.1% (CI, 11.7% to 18.2%) for a <9-g/dL strategy, 15.9% (CI, 12.4% to 19.0%) for a <8-g/dL strategy, and 18.3% (CI, 14.6% to 22.0%) for a <7-g/dL strategy. Absolute risk differences and risk ratios relative to the <10-g/dL strategy for 30-day death/MI increased as thresholds decreased, although 95% CIs were wide. Findings were similar and imprecise for 30-day death. Unmeasured confounding may have persisted despite adjustment. The 30-day risks for death/MI and death among patients with acute MI and anemia seem to increase progressively with lower hemoglobin concentration thresholds for transfusion. However, the imprecision around estimates from this target trial analysis precludes definitive conclusions about individual hemoglobin thresholds. National Heart, Lung, and Blood Institute.

Realizing near-full density monophasic tetragonal 1.5-mol% yttria-stabilized zirconia ceramics via current-ramp flash sintering

This study demonstrates the successful fabrication of near-full density monophasic tetragonal 1.5-mol% yttria-stabilized zirconia (1.5YSZ) ceramics using current-ramp flash (CRF) sintering technique. The process involved regulating Joule heating in the samples by fine-tuning the input power through an alternating current field (nominal current density: 50 mA·mm−2) within a 3-minute timeframe at a furnace temperature of 1100°C. This approach effectively enhanced grain size uniformity, which is crucial for preventing sample cracking associated with spontaneous tetragonal-to-monoclinic (T→M) phase transformation, thereby promoting densification with average relative densities exceeding 99%. The highest average fracture toughness of the 1.5YSZ samples was measured at 9.2 MPa·m0.5 using the standardized single-edge pre-cracked beam method. This toughness is approximately double that of commonly used 3YSZ samples produced by CRF sintering, all of which exhibited comparable average grain sizes and relative densities. Additionally, the 1.5YSZ samples demonstrated nearly identical resistance to low-temperature degradation (LTD) compared to the 3YSZ samples after accelerated hydrothermal aging at 140°C for 15 hours, roughly equivalent to 60 years at 37°C. The reduced yttria concentration in 1.5YSZ facilitates T→M phase transformation at lower stress thresholds, enhancing toughness through increased crack shielding from a larger volume fraction of transformed grains. Furthermore, the uniform yttria distribution in 1.5YSZ, revealed by scanning transmission electron microscopy, compensates for the reduced tetragonal phase stability and contributes to improved LTD resistance. Notably, these exceptional properties were achieved at a furnace temperature 300°C lower and with a sintering duration several hours shorter than those of conventionally-sintered counterparts.

Percolation Statistics in the MillenniumTNG Simulations

The statistical analysis of cosmic large-scale structure is most often based on simple two-point summary statistics, like the power spectrum or the two-point correlation function of a sample of galaxies or other types of tracers. In contrast, topological measures of clustering are also sensitive to higher-order correlations and thus offer the prospect to access additional information that may harbor important constraining power. We here revisit one such geometric measure of the cosmic web in the form of the so-called percolation analysis, using the recent MillenniumTNG simulation suite of the ΛCDM paradigm. We analyze continuum percolation statistics both for high-resolution dark matter particle distributions and for galaxy mock catalogs from a semianalytic galaxy formation model within a periodic simulation volume of 3000 Mpc on a side. For comparison, we also investigate the percolation statistics of random particle sets and neutrino distributions with two different summed particle masses. We find that the percolation statistics of the dark matter distribution evolves strongly with redshift and thus clustering strength, yielding a progressively lower percolation threshold toward later times. However, there is a sizable residual dependence on numerical resolution, which we interpret as a residual influence of different levels of shot noise. This is corroborated by our analysis of galaxy mock catalogs, whose results depend on sampling density more strongly than on galaxy selection criteria. While this limits the discriminative power of percolation statistics, our results suggest that it still remains useful as a complementary cosmological test when controlled for sampling density.

Altered Sensory Processing in People Attending Specialist Orthopaedic Consultation for Management of Persistent Shoulder Pain: An Observational Cross-Sectional Study.

OBJECTIVES: The primary objective was to compare sensory processing measures in people attending specialist orthopaedic consultation for management of persistent shoulder pain with control participants. The secondary objective was to compare the groups' sociodemographic, clinical, general health and lifestyle, and psychological characteristics. DESIGN: Observational cross-sectional. METHODS: Participants with shoulder pain for ≥3 months, who attended a public hospital orthopaedic department (n = 119), and community participants without shoulder pain (n = 44) underwent a standardized quantitative sensory testing protocol, measuring pressure pain threshold, temporal summation, and conditioned pain modulation. Sociodemographic, clinical, general health and lifestyle, and psychological characteristics were also collected. RESULTS: Participants with shoulder pain had significantly lower pressure pain thresholds at all sites (ie, local and widespread mechanical hyperalgesia) and significantly decreased conditioned pain modulation effect (ie, descending inhibition of nociception) than control participants. There was no significant difference between groups for temporal summation. Participants with shoulder pain had decreased general health and function, less healthy lifestyles, and poorer psychological health compared with controls. CONCLUSION: People referred to specialist orthopaedic care for management of persistent shoulder pain had clinical signs of altered sensory processing and poor health outcomes. J Orthop Sports Phys Ther 2024;54(10):1-10. Epub 25 July 2024. doi:10.2519/jospt.2024.12512.

Prognostic Value of Pulmonary Artery Systolic Pressure in Severe Rheumatic Mitral Stenosis.

Current guidelines recommend intervention for asymptomatic rheumatic mitral stenosis (MS) with mitral valve area ≤1.5 cm2 based on indicators including pulmonary arterial systolic pressure (PASP) >50 mm Hg and new-onset atrial fibrillation; however, evidence supporting this is lacking. This single-center retrospective study included patients with rheumatic MS between 2006 and 2022. Pulmonary hypertension was evaluated by using echocardiography to estimate PASP. Primary outcomes were major adverse cardiovascular events (MACE), including all-cause mortality, hospitalization for heart failure, and arterial thromboembolic events for up to 5 years. Overall, 287 patients with severe rheumatic MS were enrolled (mean age, 62.5±11.3 years; 74.6% women). During a median follow-up of 2.52 years, MACE occurred in 99 patients. There were no differences in echocardiographic parameters, such as the mean mitral valve pressure gradient, mitral valve area, and proportion of mitral valve area <1.0 cm2, between patients who developed primary outcomes and those who did not. Survival analysis showed a worse prognosis in patients with estimated PASP (ePASP) >50 mm Hg than in those with ePASP ≤50 mm Hg (log-rank P<0.001); however, atrial fibrillation was not a significant prognostic indicator. As a continuous variable, ePASP (mm Hg) was a significant predictor of MACE (adjusted hazard ratio, 1.027 [95% CI, 1.011-1.042]; P<0.001). Receiver operating characteristic analysis revealed an optimal ePASP threshold of >45 mm Hg, which was an independent predictor of MACE in patients with severe rheumatic MS (adjusted hazard ratio, 2.127 [95% CI, 1.424-3.177]; P<0.001). Competing risk analysis considering mitral valve intervention as a competing risk showed similar results. Our study demonstrated the prognostic significance of ePASP, rather than atrial fibrillation, in relation to MACE among patients with severe rheumatic MS. Additionally, we proposed a lower ePASP threshold (>45 mm Hg) as a predictor of an unfavorable prognosis.

Back to the future: Merger control outside the Merger Regulation

In 1989, the Council gave the European Commission a clear and limited legislative mandate for the control of concentrations, stipulating, among other things, that (i) the Commission’s competence must be limited to large transactions based on clearly defined turnover thresholds; (ii) the EU Merger Regulation alone should apply to concentrations; and (iii) concentrations must be reviewed within tight statutory deadlines. Since its first proposal in 1973, the Commission has been seeking lower turnover thresholds and broader powers, which the Council has consistently refused.Yet the Commission has reinterpreted Article 22 of the EU Merger Regulation to effectively give it the power to “call in” concentrations below the thresholds, advocated for Member States’ ability to apply the EU antitrust rules to concentrations, and developed procedural tools and practices (including the concept of “up-front buyer” commitments) that allow it to ignore the strict statutory time limits in practice. It is time for a reset to align the Commission’s practice with its legislative mandate.

Impact of implementing stricter criteria for blood transfusion in patients with head and neck cancer undergoing free tissue transfer.

Recent literature studying the impact of blood transfusion on outcomes in patients with head and neck cancer (HNC) have shown that blood transfusions are associated with increased risk of death and higher wound infection rates. The purpose of this study was to implement a lower transfusion threshold while comparing outcomes of free flap patients following initiation of a new transfusion guideline. A retrospective study of all patients at a tertiary care academic center who underwent free tissue transfer after HNC resection between July 17, 2007 and June 7, 2021. Transfusion criteria were adjusted in 2014; the hematocrit threshold to transfuse was incrementally reduced from 30% in 2007 to 21% in 2017. The main outcomes of interest were overall survival (OS) and recurrence free survival (RFS). A total of 346 patients met the criteria for inclusion in the study. Groups 1 (less strict protocol - 30%) and 2 (stricter protocol - 21%) consisted of 171 and 175 patients, respectively. Fewer units of packed red cells were transfused per patient in group 2 (0.26 vs. 2.87 in group 1, p < .001). Group 1 was associated with worse OS (p = .01; hazard ratio [HR] = 1.7) and RFS (p < .001; HR = 2.5). Comparing only patients with SCC between the two groups also demonstrated poorer OS (p = .01; HR = 1.8) and RFS (p = .006; HR = 2.1) in group 1. In HNC patients undergoing free tissue transfer, stricter transfusion criteria with threshold hematocrit of 21% was associated with improved OS, RFS, and complication rates with no negative impact on free flap survival. Level IV.

Characteristics and Dosimetric Properties of Tissue-Equivalent Thermoluminescent Glass Detector Based on Al-Li-Zn, Borate Oxide Dope Dy3+

Functionality and dosimetric properties of a tissue-equivalent thermoluminescent glass detector doped with Dy3+. This work investigated an Aluminium-Lithium-Zinc borate oxide matrix using the melting-quench method. X-ray diffraction confirms the glass sample is amorphous. Dysprosium ions doping raises the glass’s tissue equivalent effective atomic number (Zeff.), improving its ability to absorb radiation and its sensitivity, with reproducibility almost at the tolerable limit. The glass detector also reduces the fading rate and signal loss over time. The minimum detectable dose values were 53.04 mGy and 45.1 mGy for the un-doped and 1.5 mol Dy3+ doped Al-Li-Zn borate glasses, respectively. A bright peak was seen in photoluminescence spectra at 348 nm (yellow), 529 nm (green), and 625 nm (orange hue). These correspond to the Dy3+ transitions at 4H15/2 → 6P7/2, 4F9/2 → 6H15/2, 4F9/2 → 6H15/2, and 4F9/2 → 6H13/2 , respectively. There was a noticeable drop in Tg from 257°C in the undoped sample to 101°C in the doped sample, Tm from 862°C to 815°C, and Tc from 756°C to 444°C in the doped sample. These results may indicate a lower temperature at which the material transitions from a solid to a liquid state and a lower crystallisation threshold. The frequency component and energy of activation of the 1.5 mol Dy3+ doped Aluminium-Lithium-Zinc borate are 2.1×10 27 s-1 and 1.03 eV, respectively. The 1.5 Dy3+ doped Aluminium-Lithium-Zinc borate glasses exhibit promising dosimetric properties of the tissue-equivalent thermoluminescent glass detector, indicating its potential for accurate and consistent radiation dosimetry in various applications.

Conductivity of PLA/PBAT blends with carbon black as a conductive filler

Conductive composites of PLA/PBAT/CB were prepared by melt blending. CB selectively distributes in the PBAT matrix, and at a PLA to PBAT ratio of 1:1, the composite achieves a conductivity of 1.01 × 10−6 S/m with a percolation threshold of 0.42 wt%. Compared to PLA/CB and PBAT/CB, the PLA/PBAT/CB composite has a lower percolation threshold. The E2 processing sequence most effectively enhanced conductivity by optimizing carbon black distribution in the PBAT phase, promoting a co-continuous structure and improving conductive pathways and electrical properties. Key methods used include contact angle measurements, polarized light microscopy, scanning electron microscopy, and a high-resistance meter.

Acute adnexa with preserved flow to the ovary: Could isolated tubal torsion be the cause?

Isolated tubal torsion (ITT) is a surgical emergency that is less well characterized than ovarian torsion and presents with its own diagnostic challenges. We retrospectively examined patients with ITT and compared them to patients with ovarian torsion to better understand the unique features of this pathophysiologic process. The medical records of patients who were identified as having ITT or ovarian torsion intraoperatively between January 2019 and November 2022 were reviewed. Patient demographics, clinical documentation, diagnostic imaging reports, operative reports, and pathology results were collected. A total of 82 patients met inclusion criteria of which 62 (75.6%) had ovarian torsion and 20 (24.4%) had ITT. Most patients (63.4%) underwent 2 or more imaging studies prior to the operating room. A diagnosis of torsion occurred more often on preoperative imaging for the ovarian torsion group (67.7% ovarian torsion vs 35.0% ITT, p=0.01). Doppler flow to the ovary was expectedly absent in 65.9% of ovarian torsion patients but interestingly also absent in 25% of ITT patients (p=0.01). Patients with ovarian torsion were more likely to have ovarian cysts (56.5% vs 10.0%, p<0.001), while patients with ITT were significantly more likely to have a paratubal cyst (90.0% vs 38.7%, p<0.001). ITT is a surgical emergency that poses a risk to future fertility. Ultrasound studies, including doppler, may not be as definitive in patients with ITT and early cross-sectional imaging should be considered. When there is a high clinical suspicion for ovarian torsion or ITT, there should be a low threshold for diagnostic laparoscopy.

Reducing dislocations for room-temperature continuous-wave InGaAs/AlGaAs multiple quantum well lasers monolithically grown on Si

As dislocation-sensitive light-emitting devices, quantum well lasers monolithically grown on Si substrates operate poorly compared to their counterparts on native ones. In this work, a GaAs/Si virtual substrate with a low threading dislocation density of 8.9×106/cm2 was achieved by using a combined dislocation-reducing method. Meanwhile, by using two In-containing strained layer separately inserted into upper and lower AlGaAs cladding layers, the active region was virtually free of gliding dislocations. With the reduced dislocations in the active region, the fabricated Si-based broad-stripe ridged lasers exhibited continuous-wave lasing at room temperature, and a low threshold current density of 1015 A/cm2, high operation temperature of 90°C as well as a device lifetime of over 87.25 h were achieved. These results demonstrate an experimentally feasible way to optimize a Si-based InGaAs/AlGaAs quantum well laser and further promote the research on monolithic integration.

A Regional-Scale Assessment-Based SARS-CoV-2 Variants Control Modeling with Implications for Infection Risk Characterization.

The emergence and progression of highly divergent SARS-CoV-2 variants have posed increased risks to global public health, triggering the significant impacts on countermeasures since 2020. However, in addition to vaccination, the effectiveness of non-pharmaceutical interventions, such as social distancing, masking, or hand washing, on different variants of concern (VOC) remains largely unknown. This study provides a mechanistic approach by implementing a control measure model and a risk assessment framework to quantify the impacts of control measure combinations on the transmissions of five VOC (Alpha, Beta, Delta, Gamma, and Omicron), along with a different perspective of risk assessment application. We applied uncontrollable ratios as an indicator by adopting basic reproduction number (R 0) data collected from a regional-scale survey. A risk assessment strategy was established by constructing VOC-specific dose-response profiles to implicate practical uses in risk characterization when exposure data are available. We found that social distancing alone was ineffective without vaccination in almost all countries and VOC when the median R 0 was greater than two. Our results indicated that Omicron could not be contained, even when all control measure combinations were applied, due to its low threshold of infectivity (~3×10-4 plague-forming unit (PFU) mL-1). To facilitate better decision-making in future interventions, we provide a comprehensive evaluation of how combined control measures impact on different countries and various VOC. Our findings indicate the potential application of threshold estimates of infectivity in the context of risk communication and policymaking for controlling future emerging SARS-CoV-2 variant infections.

Patient-Determined Important Change for the Neck Disability Index With Application of Credibility Analysis: An Exploratory Study

ObjectiveThe purposes of this study were to preliminarily report patient-identified change for the neck disability index (NDI) as either important or not important with time between follow-up of approximately 7 to 10 days and assess the credibility of the preliminary results with the use of a recently established credibility instrument. MethodsThis study was a secondary analysis from a primary randomized clinical trial assessing short-term physical therapist care for individuals with mechanical neck pain. Neck disability index scores and participant-reported importance of global rating of change scores from 42 participants were analyzed from a randomized clinical trial assessing short-term responses to thoracic manipulation and dry needling for neck pain. Patient-important change was computed using receiver operating characteristic curves, and statistical error of the measurement was calculated using (SD × [1 − r]1/2) × 1.96 to assess measurement error at the 95% CI. ResultsThirty-six participants rated global rating of change as important, and 6 rated it as not important. Patient-important change was calculated at 3.5 NDI points on a 0 to 50 NDI scoring scale. This value exceeded the statistical error, which was calculated at 2.16 NDI points. The credibility analysis revealed that 4 of 5 criteria showed strong credibility for the patient-important change estimate. ConclusionUsing patient-determined importance to dichotomize improvement may yield a lower threshold than current researcher-defined methods. Clinically, these results may be more responsive to patient-centric change than using previously reported minimal clinically important difference data.