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Nevin Manimala Statistics

Discrete breathers in Klein-Gordon lattices: A deflation-based approach

Chaos. 2023 Nov 1;33(11):113126. doi: 10.1063/5.0161889.

ABSTRACT

Deflation is an efficient numerical technique for identifying new branches of steady state solutions to nonlinear partial differential equations. Here, we demonstrate how to extend deflation to discover new periodic orbits in nonlinear dynamical lattices. We employ our extension to identify discrete breathers, which are generic exponentially localized, time-periodic solutions of such lattices. We compare different approaches to using deflation for periodic orbits, including ones based on Fourier decomposition of the solution, as well as ones based on the solution’s energy density profile. We demonstrate the ability of the method to obtain a wide variety of multibreather solutions without prior knowledge about their spatial profile.

PMID:37988609 | DOI:10.1063/5.0161889

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Nevin Manimala Statistics

Prehospital lactate-glucose interaction in acute life-threatening illnesses: metabolic response and short-term mortality

Eur J Emerg Med. 2023 Nov 8. doi: 10.1097/MEJ.0000000000001102. Online ahead of print.

ABSTRACT

BACKGROUND AND IMPORTANCE: Lactate is an already recognized biomarker for short-term mortality. However, how glycemia and diabetes affect the predictive ability of lactate needs to be revealed.

OBJECTIVE: To determine how hypoglycemia, normoglycemia, and hyperglycemia modify the predictive ability of lactate for short-term mortality (3 days). The secondary objective was to evaluate the predictive ability of lactate in diabetic patients.

DESIGN, SETTINGS AND PARTICIPANTS: Prospective, observational study performed between 26 October 2018 and 31 December 2022. Multicenter, EMS-delivery, ambulance-based study, considering 38 basic life support units and 5 advanced life support units referring to four tertiary care hospitals (Spain). Eligible patients were adults recruited from among all phone requests for emergency assistance who were later evacuated to emergency departments.

OUTCOMES MEASURE AND ANALYSIS: The primary outcome was in-hospital mortality from any cause within the third day following EMS attendance. The main predictors considered were lactate, blood glucose levels and previous diabetes.

MAIN RESULTS: A total of 6341 participants fulfilled the inclusion criteria. 68 years (IQR: 51-80); 41.4% were female. The 3-day in-hospital mortality rate was 3.5%. The predictive capacity of lactate for 3-day mortality was only significantly different between normo-glycemia and hyperglycemia. The best predictive result was for normo-glycemia – AUC = 0.897 (95% CI: 0.881-0.913) – then hyperglycemia – AUC = 0.819 (95% CI: 0.770-0.868) and finally, hypoglycemia – AUC = 0.703 (95% CI: 0.422-0.983). The stratification according to diabetes presented no statistically significant difference, and the predictive results were AUC = 0.924 (95% CI: 0.892-0.956), AUC = 0.906 (95% CI: 0.884-0.928), and AUC = 0.872 (95% CI: 0.817-0.927) for nondiabetes, uncomplicated cases, and end-organ damage diabetes, respectively.

CONCLUSION: Our results demonstrated that glycemia, but not diabetes, alters the predictive ability of lactate. Therefore, hyperglycemia should be considered when interpreting lactate, since this could improve screening to detect cryptic shock conditions.

PMID:37988474 | DOI:10.1097/MEJ.0000000000001102

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Nevin Manimala Statistics

Influence of fabrication settings on the in-vitro performance of subtractively manufactured resin-based molar crowns

Int J Prosthodont. 2023 Nov 21;0(0):1-13. doi: 10.11607/ijp.8779. Online ahead of print.

ABSTRACT

PURPOSE: To investigate the influence of milling parameters on the durability during in-vitro aging-simulation, and fracture force of resin-based composite crowns.

MATERIALS AND METHODS: Identical molar crowns (n=8 per group) were milled from resin-based composite crowns (Grandio, VOCO, Germany) with different processing speed (soft, normal, fast) or level of details (very high, high, low) form 98mm discs. To investigate the influence of cooling, one group was milled wet. The influence of polishing was tested in two groups. All crowns were adhesively bonded on standardized resin-based composite molars. Aging was performed with thermal cycling and mechanical loading (2x3000x5°C/55°C, 2min, H20 dist., 1.2×106 force 50N). Fracture forces were determined (v=1mm/min, Z010, Zwick, Germany).

STATISTICS: Pearson-correlation, one-way ANOVA, Bonferroni post-hoc-tests (α=0.05).

RESULTS: All crowns survived TCML without any failures. The fracture values varied between 1237.3 ± 326.7N and 3308.6 ± 655.8N. Significant (p<0.001) differences between the individual manufacturing approaches were detected. Failure was categorized as a fracture of the crown and partial loosening of the crown. No different failure pattern was observed between the tested systems.

CONCLUSION: A medium level of detail seems to be ideal to achieve highest fracture forces. No relationship existed between machining speed and fracture force. Fracture force was not affected by wet grinding. In individual cases, polishing reduced crown fracture values, due to reduced wall thickness.

PMID:37988433 | DOI:10.11607/ijp.8779

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Nevin Manimala Statistics

Evaluation of the labial protrusion and lip esthetic changes after complete denture treatment through stereophotogrammetry

Int J Prosthodont. 2023 Nov 21;0(0):1-25. doi: 10.11607/ijp.8623. Online ahead of print.

ABSTRACT

PURPOSE: Evaluating the facial esthetics of complete denture (CD) treatment using a 3D analysis of the lower third of the face before (T1) and after (T2) treatment by comparing and correlating measurements.

MATERIAL AND METHODS: Thirty-one edentulous patients were enrolled, and three-dimensional (3D) images were captured before (T1) and after (T2) CD delivery. Twelve landmarks were established in the face. Linear, angular, surface, and perimeter measurements were evaluated and compared with the paired t test. The delta (Δ) values (T2-T1) were assessed by the Spearman correlation to verify the associations between all measurements according to the facial parameters (α=.05).

RESULTS: Statistical differences were identified in the lower third of the face in the linear measurement Sn-Gn (P = 0.006), the angular measure Tright-Pg-Tleft (P = 0.004), and at the surface of the lower third of the face (P = 0.001). All measurements were statistically different in the labial protrusion area: the nasolabial angle (Prn-Sn-Ls), the surface, and the perimeter (P = 0.001). In the lip evaluation, statistical differences were observed in the linear (Ls-Li), surface, and perimeter measurements (P = 0.001).

CONCLUSION: The facial esthetic proportions of the linear and perimeter measurements increased, and the angles of sealed lips and nasolabial and lower facial convexity decreased after CD delivery. The present study showed a clinical important correlation between linear and angular measurements that should help restore facial esthetics, providing metrics that can aid the clinician in facial composition.

PMID:37988431 | DOI:10.11607/ijp.8623

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Nevin Manimala Statistics

Survival analysis and prevalence of biological and technical complications in fully edentulous patients rehabilitated with different modalities of complete dentures: A retrospective study in Zurich (part I)

Int J Prosthodont. 2023 Nov 21;0(0):1-33. doi: 10.11607/ijp.8691. Online ahead of print.

ABSTRACT

PURPOSE: This study aimed to evaluate the prevalence of biological and technical/mechanical complications in edentate elders rehabilitated with complete removable dental prostheses (CDs) and overdentures [tooth-retained (ODs), implant-retained (IODs)].

MATERIALS AND METHODS: Patient records of adults (>60y) rehabilitated with CDs, ODs, and IODs were included. Demographic information (age, sex), information on the prostheses type, number/type of biological/prosthetic complications, along with the number/time of the complications, were extracted.Kaplan-Meier model was used for the statistical analyses.

RESULTS: 162 patients (mean age: 74.5±9.45y; prostheses: n=224, CD=172; OD=21; IOD=31) were included. The average period of function in situ was 19.70±27.66, 32.72±27.84, and 31.73±32.67 months, for the CDs, ODs, and IODs, respectively. 5 prostheses failed. Survival analysis revealed an overall survival rate (SR) of 97.8%, with individual five-year cumulative survival probability of 96.1% for CDs, 94.1% for ODs, and 100.0% for IODs. There were no significant survival differences between maxillary and mandibular prostheses within each type of rehabilitation. In the maxilla, no significant differences were found in maintenance visit times due to prosthodontic complications among the different types of prostheses. Patients with mandibular CDs required maintenance visits earlier compared to mandibular ODs (p<0.001) and IODs (p<0.001). Patients with mandibular ODs also required maintenance visits earlier than those with mandibular IODs (p=0.005).

CONCLUSIONS: Rehabilitation of the edentate jaws, whether with CDs, ODs, or IODs, is a predictable treatment modality with high survival rates. Differences in maintenance visit times were observed, with CDs and ODs in the mandible requiring earlier visits compared to IODs.

PMID:37988428 | DOI:10.11607/ijp.8691

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Nevin Manimala Statistics

A Framework for Improving the Generalizability of Drug-Target Affinity Prediction Models

J Comput Biol. 2023 Nov;30(11):1226-1239. doi: 10.1089/cmb.2023.0208.

ABSTRACT

Statistical models that accurately predict the binding affinity of an input ligand-protein pair can greatly accelerate drug discovery. Such models are trained on available ligand-protein interaction data sets, which may contain biases that lead the predictor models to learn data set-specific, spurious patterns instead of generalizable relationships. This leads the prediction performances of these models to drop dramatically for previously unseen biomolecules. Various approaches that aim to improve model generalizability either have limited applicability or introduce the risk of degrading overall prediction performance. In this article, we present DebiasedDTA, a novel training framework for drug-target affinity (DTA) prediction models that addresses data set biases to improve the generalizability of such models. DebiasedDTA relies on reweighting the training samples to achieve robust generalization, and is thus applicable to most DTA prediction models. Extensive experiments with different biomolecule representations, model architectures, and data sets demonstrate that DebiasedDTA achieves improved generalizability in predicting drug-target affinities.

PMID:37988395 | DOI:10.1089/cmb.2023.0208

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Nevin Manimala Statistics

Heavy-tailed distributions of confirmed COVID-19 cases and deaths in spatiotemporal space

PLoS One. 2023 Nov 21;18(11):e0294445. doi: 10.1371/journal.pone.0294445. eCollection 2023.

ABSTRACT

This paper conducts a systematic statistical analysis of the characteristics of the geographical empirical distributions for the numbers of both cumulative and daily confirmed COVID-19 cases and deaths at county, city, and state levels over a time span from January 2020 to June 2022. The mathematical heavy-tailed distributions can be used for fitting the empirical distributions observed in different temporal stages and geographical scales. The estimations of the shape parameter of the tail distributions using the Generalized Pareto Distribution also support the observations of the heavy-tailed distributions. According to the characteristics of the heavy-tailed distributions, the evolution course of the geographical empirical distributions can be divided into three distinct phases, namely the power-law phase, the lognormal phase I, and the lognormal phase II. These three phases could serve as an indicator of the severity degree of the COVID-19 pandemic within an area. The empirical results suggest important intrinsic dynamics of a human infectious virus spread in the human interconnected physical complex network. The findings extend previous empirical studies and could provide more strict constraints for current mathematical and physical modeling studies, such as the SIR model and its variants based on the theory of complex networks.

PMID:37988387 | DOI:10.1371/journal.pone.0294445

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Nevin Manimala Statistics

World Health Organization Danger Signs to predict bacterial sepsis in young infants: A pragmatic cohort study

PLOS Glob Public Health. 2023 Nov 21;3(11):e0001990. doi: 10.1371/journal.pgph.0001990. eCollection 2023.

ABSTRACT

Bacterial sepsis is generally a major concern in ill infants. To help triaging decisions by front-line health workers in these situations, the World Health Organization (WHO) has developed danger signs (DS). The objective of this study was to evaluate the extent to which nine DS predict bacterial sepsis in young infants presenting with suspected sepsis in a low-income country setting. The study pragmatically evaluated nine DS in infants younger than 3 months with suspected sepsis in a regional hospital in Lilongwe, Malawi, between June 2018 and April 2020. Main outcomes were positive blood or cerebrospinal fluid (CSF) cultures for neonatal pathogens, and mortality. Among 401 infants (gestational age [mean ± SD]: 37.1±3.3 weeks, birth weight 2865±785 grams), 41 had positive blood or CSF cultures for a neonatal pathogen. In-hospital mortality occurred in 9.7% of infants overall (N = 39/401), of which 61.5% (24/39) occurred within 48 hours of admission. Mortality was higher in infants with bacterial sepsis compared to other infants (22.0% [9/41] versus 8.3% [30/360]; p = 0.005). All DS were associated with mortality except for temperature instability and tachypnea, whereas none of the DS were significantly associated with bacterial sepsis, except for “unable to feed” (OR 2.25; 95%CI: 1.17-4.44; p = 0.017). The number of DS predicted mortality (OR: 1.75; 95%CI: 1.43-2.17; p<0.001; AUC: 0.756), but was marginally associated with positive cultures with a neonatal pathogen (OR 1.22; 95%CI: 1.00-1.49; p = 0.046; AUC: 0.743). The association between number of DS and mortality remained significant after adjusting for admission weight, the only statistically significant co-variable (OR 1.75 [95% CI: 1.39-2.23]; p<0.001). Considering all positive cultures including potential bacterial contaminants resulted a non-significant association between number of DS and sepsis (OR 1.09 [95% CI: 0.93-1.28]; p = 0.273). In conclusion, this study shows that DS were strongly associated with death, but were marginally associated with culture-positive pathogen sepsis in a regional hospital setting. These data imply that the incidence of bacterial sepsis and attributable mortality in infants in LMIC settings may be inaccurately estimated based on clinical signs alone.

PMID:37988384 | DOI:10.1371/journal.pgph.0001990

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Nevin Manimala Statistics

Target strength measurements of individual sub-Arctic krill have frequency-dependent differences from scattering model predictions

J Acoust Soc Am. 2023 Nov 1;154(5):3374-3387. doi: 10.1121/10.0022459.

ABSTRACT

Target strength (TS) is commonly used to convert acoustic backscatter from marine organisms to numerical abundance estimates. Shipboard, tank-based TS measurements were made on four sub-Arctic krill species (Euphausia pacifica, Thysanoessa spinifera, Thysanoessa inermis, and Thysanoessa raschii) from the eastern Bering Sea and Gulf of Alaska at discrete frequencies between 42 and 455 kHz. These measurements were compared to scattering model predictions parameterized with data from the same (when possible) individual krill. Statistically significant differences between modeled and experimental estimates at 42, 45, 120, and 131 kHz exceeded 2 dB on average. Variability in the signal-to-noise ratio, animal length, and measurements from two separate narrowband and broadband transducer pairs (at those frequencies) did not account for these differences. Scattering predictions at 120 and 131 kHz were consistent with the expected transition from Rayleigh-to-geometric scattering where models become increasingly sensitive to orientation and body shape variability. Disagreement between modeled and measured TS may be due to using scattering models developed for, and validated on, larger krill (i.e., Euphausia superba) rather than smaller species of krill. Acoustic surveys of smaller (15-30 mm) krill may require further validation of both the generalizability and parameterization of applied scattering models.

PMID:37988372 | DOI:10.1121/10.0022459

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Nevin Manimala Statistics

Alexithymia as a risk factor for poor emotional outcomes in adults with acquired brain injury

Neuropsychol Rehabil. 2023 Dec;33(10):1650-1671. doi: 10.1080/09602011.2022.2140680. Epub 2022 Nov 3.

ABSTRACT

Emotional disorders are pervasive in the acquired brain injury (ABI) population, adversely affecting quality of life and rehabilitation. This study aimed to explore the unique associative effects of alexithymia as measured by the Perth Alexithymia Questionnaire (PAQ; i.e., difficulty identifying positive/negative feelings, difficulty describing positive/negative feelings, and externally orientated thinking), on emotional outcomes as measured by the Depression Anxiety Stress Scale-21 (DASS-21) and Mayo-Portland Adaptability Inventory (MPAI-4) Adjustment index, in 83 adults with ABI. The addition of alexithymia to hierarchical multiple regression models (controlling for demographic, injury-related, and functional outcome variables) yielded statistically significant changes in R2 for all emotional outcome measures (i.e., Depression, Anxiety, Stress, and Adjustment). Difficulty identifying negative feelings was found to be a significant unique predictor of Depression (β = .43 p = <.001), Anxiety (β = .40, p <.001), Stress (β = .49, p <.001), and Adjustment (β = .26, p = .001). Externally oriented thinking was found to be a significant unique predictor of Adjustment (β = -.15, p = .033). These findings strengthen the argument that alexithymia, especially difficulties identifying negative feelings, may be an important risk factor for psychological distress in ABI and should be considered during early rehabilitation.

PMID:37988367 | DOI:10.1080/09602011.2022.2140680