Critical Threshold Research Articles

Travelling waves for a fast reaction limit of a discrete coagulation-fragmentation model with diffusion and proliferation.

We study traveling wave solutions for a reaction-diffusion model, introduced in the article Calvez et al. (Regime switching on the propagation speed of travelling waves of some size-structured myxobacteriapopulation models, 2023), describing the spread of the social bacterium Myxococcus xanthus. This model describes the spatial dynamics of two different cluster sizes: isolated bacteria and paired bacteria. Two isolated bacteria can coagulate to form a cluster of two bacteria and conversely, a pair of bacteria can fragment into two isolated bacteria. Coagulation and fragmentation are assumed to occur at a certain rate denoted by k. In this article we study theoretically the limit of fast coagulation fragmentation corresponding mathematically to the limit when the value of the parameter k tends to . For this regime, we demonstrate the existence and uniqueness of a transition between pulled and pushed fronts for a certain critical ratio between the diffusion coefficient of isolated bacteria and the diffusion coefficient of paired bacteria. When the ratio is below , the critical front speed is constant and corresponds to the linear speed. Conversely, when the ratio is above the critical threshold, the critical spreading speed becomes strictly greater than the linear speed.

Searching for LINCS to Stress: Using Text Mining to Automate Reference Chemical Curation.

Adaptive stress response pathways (SRPs) restore cellular homeostasis following perturbation but may activate terminal outcomes like apoptosis, autophagy, or cellular senescence if disruption exceeds critical thresholds. Because SRPs hold the key to vital cellular tipping points, they are targeted for therapeutic interventions and assessed as biomarkers of toxicity. Hence, we are developing a public database of chemicals that perturb SRPs to enable new data-driven tools to improve public health. Here, we report on the automated text-mining pipeline we used to build and curate the first version of this database. We started with 100 reference SRP chemicals gathered from published biomarker studies to bootstrap the database. Second, we used information retrieval to find co-occurrences of reference chemicals with SRP terms in PubMed abstracts and determined pairwise mutual information thresholds to filter biologically relevant relationships. Third, we applied these thresholds to find 1206 putative SRP perturbagens within thousands of substances in the Library of Integrated Network-Based Cellular Signatures (LINCS). To assign SRP activity to LINCS chemicals, domain experts had to manually review at least three publications for each of 1206 chemicals out of 181,805 total abstracts. To accomplish this efficiently, we implemented a machine learning approach to predict SRP classifications from texts to prioritize abstracts. In 5-fold cross-validation testing with a corpus derived from the 100 reference chemicals, artificial neural networks performed the best (F1-macro = 0.678) and prioritized 2479/181,805 abstracts for expert review, which resulted in 457 chemicals annotated with SRP activities. An independent analysis of enriched mechanisms of action and chemical use class supported the text-mined chemical associations (p < 0.05): heat shock inducers were linked with HSP90 and DNA damage inducers to topoisomerase inhibition. This database will enable novel applications of LINCS data to evaluate SRP activities and to further develop tools for biomedical information extraction from the literature.

Study on Early Identification of Rainfall-Induced Accumulation Landslide Hazards in the Three Gorges Reservoir Area

The early identification of potential hazards is crucial for landslide early warning and prevention and is a key focus and challenging issue in landslide disaster research. The challenges of traditional investigation and identification methods include identifying potential hazards of landslides triggered by heavy rainfall and mapping areas susceptible to landslides based on rainfall conditions. This article focuses on the problem of early identification of rainfall-induced accumulation landslide hazards and an early identification method is proposed, which is “first identifying the accumulation that is prone to landslides and then determining the associated rainfall conditions”. This method is based on identifying the distribution and thickness of accumulation, analyzing the rainfall conditions that trigger landslides with varying characteristics, and establishing rainfall thresholds for landslides with different accumulation characteristics, ultimately aiming to achieve early identification of accumulation landslide hazards. In this study, we focus on the Zigui section of the Three Gorges Reservoir as study the area, and eight main factors that influence the distribution and thickness of accumulation are extracted from multi-source data, then the relative thickness information extraction model of accumulation is established by using the BP neural network method. The accumulation distribution and relative thickness map of the study area are generated, and the study area is divided into rocky area (less than 1 m), thin (1 to 5 m), medium (5 to 10 m), and thick area (thicker than 10 m) according to accumulation thickness. Rainfall is a significant trigger for landslide hazards. It increases the weight of the sliding mass and decreases the shear strength of soil and rock layers, thus contributing to landslide events. Data on 101 rainfall-induced accumulation landslides in the Three Gorges Reservoir area and rainfall data for the 10 days prior to each landslide event were collected. The critical rainfall thresholds corresponding to a 90% probability of landslide occurrence with different characteristics were determined using the I-D threshold curve method. Prediction maps of accumulation landslide hazards under various rainfall conditions were generated by analyzing the rainfall threshold for landslides in the Three Gorges Reservoir area, serving as a basis for early identification of rainfall-induced accumulation landslides in the region. The research provides a method for the early identification of landslides caused by heavy rainfall, delineating landslide hazards under different rainfall conditions, and providing a basis for scientific responses, work arrangements, and disaster prevention and mitigation of landslides caused by heavy rainfall.

Commissioning of a novel PET-Linac for biology-guided radiotherapy (BgRT).

Biology-guided radiotherapy (BgRT) is a novel radiotherapy delivery technique that utilizes the tumor itself to guide dynamic delivery of treatment dose to the tumor. The RefleXion X1 system is the first radiotherapy system developed to deliver SCINTIX® BgRT. The X1 is characterized by its split arc design, employing two 90-degree positron emission tomography (PET) arcs to guide therapeutic radiation beams in real time, currently cleared by FDA to treat bone and lung tumors. This study aims to comprehensively evaluate the capabilities of the SCINTIX radiotherapy delivery system by evaluating its sensitivity to changes in PET contrast, its adaptability in the context of patient motion, and its performance across a spectrum of prescription doses. A series of experimental scenarios, both static and dynamic, were designed to assess the SCINTIX BgRT system's performance, including an end-to-end test. These experiments involved a range of factors, including changes in PET contrast, motion, and prescription doses. Measurements were performed using a custom-made ArcCHECK insert which included a 2.2cm spherical target and a c-shape structure that can be filled with a PET tracer with varying concentrations. Sinusoidal and cosine4 motion patterns, simulating patient breathing, was used to test the SCINTIX system's ability to deliver BgRT during motion-induced challenges. Each experiment was evaluated against specific metrics, including Activity Concentration (AC), Normalized Target Signal (NTS), and Biology Tracking Zone (BTZ) bounded dose-volume histogram (bDVH) pass rates. The accuracy of the delivered BgRT doses on ArcCHECK and EBT-XD film were evaluated using gamma 3%/2mm and 3%/3mm analysis. In static scenarios, the X1 system consistently demonstrated precision and robustness in SCINTIX dose delivery. The end-to-end delivery to the spherical target yielded good results, with AC and NTS values surpassing the critical thresholds of 5 kBq/mL and 2, respectively. Furthermore, bDVH analysis consistently confirmed 100% pass rates. These results were reaffirmed in scenarios involving changes in PET contrast, emphasizing the system's ability to adapt to varying PET avidities. Gamma analysis with 3%/2mm (10% dose threshold) criteria consistently achieved pass rates>91.5% for the static tests. In dynamic SCINTIX delivery scenarios, the X1 system exhibited adaptability under conditions of motion. Sinusoidal and cosine4 motion patterns resulted in 3%/3mm gamma pass rates>87%. Moreover, the comparison with gated stereotactic body radiotherapy (SBRT) delivery on a conventional c-arm Linac resulted in 93.9% gamma pass rates and used as comparison to evaluate the interplay effect. The 1cm step shift tests showed low overall gamma pass rates of 60.3% in ArcCHECK measurements, while the doses in the PTV agreed with the plan with 99.9% for 3%/3mm measured with film. The comprehensive evaluation of the X1 radiotherapy delivery system for SCINTIX BgRT demonstrated good agreement for the static tests. The system consistently achieved critical metrics and delivered the BgRT doses per plan. The motion tests demonstrated its ability to co-localize the dose where the PET signal is and deliver acceptable BgRT dose distributions.

We cannot afford another lost year for food and climate action

ABSTRACT In recent years, recognition has grown of the significant role that food systems play in driving climate change, constituting about one-third of global greenhouse gas emissions, while also playing a key role in sequestering carbon and adapting to climate changes. The COP28 climate conference signaled a pivotal shift, spotlighting food and agriculture in discourse. However, despite pledges and declarations, concrete plans and targets to address emissions from food chains remain elusive. Urgent action is imperative to transform food systems and avert surpassing critical warming thresholds.

Nonlinear Effects of Land-Use Conflicts in Xinjiang: Critical Thresholds and Implications for Optimal Zoning

Land-use conflicts (LUCs) are pivotal in assessing human–land interaction, reflecting the intricate interplay between natural and anthropogenic drivers. However, existing studies often overlook nuanced non-linear responses and critical threshold recognition, focusing solely on linear correlations between isolated factors and LUCs. This study, situated in Xinjiang, China’s arid and semiarid region, introduces a novel analytical framework and threshold application model for LUCs. Integrating land-use and socioeconomic data, we quantified LUCs using Fragstats, correlation analysis, and restricted cubic spline (RCS) regression. Exploring non-linear dynamics between LUCs and 14 potential drivers, including natural and anthropogenic factors, we identified critical thresholds. LUC zones were delineated using a four-quadrant method, allowing tailored mitigation strategies. Our findings reveal Xinjiang’s distinct LUC spatial pattern, with intense conflicts surrounding mountainous areas and milder conflicts in basin regions, showing marked diminishment from 2000 to 2020. RCS effectively identifies LUC thresholds, indicating persisting severity pre- or post-specific thresholds. Xinjiang’s LUCs are categorized into key control areas, urgent regulation zones, elastic development territories, and moderate optimization regions, each with significant regional disparities. Tailored optimization suggestions mitigate linear analysis limitations, providing a fresh perspective on land zoning optimization. This research supports comprehensive land management and planning in Xinjiang, China.

A comprehensive analysis of key factors’ impact on environmental performance: Evidence from Globe by novel super learner algorithm

This study aims to analyze comprehensively the impact of different economic and demographic factors, which affect economic development, on environmental performance. In this context, the study considers the Environmental Performance Index as the response variable, uses GDP per capita, tariff rate, tax burden, government expenditure, inflation, unemployment, population, income tax rate, public debt, FDI inflow, and corporate tax rate as the explanatory variables, examines 181 countries, performs a novel Super Learner (SL) algorithm, which includes a total of six machine learning (ML) algorithms, and uses data for the years 2018, 2020, and 2022. The results demonstrate that (i) the SL algorithm has a superior capacity with regard to other ML algorithms; (ii) gross domestic product per capita is the most crucial factor in the environmental performance followed by tariff rates, tax burden, government expenditure, and inflation, in order; (iii) among all, the corporate tax rate has the lowest importance on the environmental performance followed by also foreign direct investment, public debt, income tax rate, population, and unemployment; (iv) there are some critical thresholds, which imply that the impact of the factors on the environmental performance change according to these barriers. Overall, the study reveals the nonlinear impact of the variables on environmental performance as well as their relative importance and critical threshold. Thus, the study provides policymakers valuable insights in re-formulating their environmental policies to increase environmental performance. Accordingly, various policy options are discussed.

OR10-2 | Identifying a Critical Threshold of Lactate Elevation in Cardiogenic Shock Using a Novel Measurement: The Lactate Time Integral

OR10-2 | Identifying a Critical Threshold of Lactate Elevation in Cardiogenic Shock Using a Novel Measurement: The Lactate Time Integral

Modelling lower-limb peripheral arterial disease using clinically available datasets: impact of inflow boundary conditions on hemodynamic indices for restenosis prediction

Modelling lower-limb peripheral arterial disease using clinically available datasets: impact of inflow boundary conditions on hemodynamic indices for restenosis prediction

Advanced Integration of Microwave Kiln Technology in Enhancing the Lost-Wax Glass Casting Process: A Study on Methodological Innovations and Practical Implications

Lost-wax glass casting, an esteemed yet technically demanding art form, traditionally relies on specialized, costly kiln equipment, presenting significant barriers to artists regarding equipment affordability, energy efficiency, and the technical mastery required for temperature control. Therefore, this study introduces an innovative approach by integrating a microwave kiln with standard household microwave ovens, thus facilitating the lost-wax glass casting process. This methodological adaptation allows artists to employ readily available home appliances for glass creation, significantly reducing the process’s cost and complexity. Our experimental investigations reveal that, by using a 500W household microwave oven for heating, the silicon carbide (SiC) in microwave kilns can efficiently absorb microwave energy, allowing the kilns to reach temperatures exceeding 700 °C, a critical threshold for casting glass softening. We further demonstrate that by adjusting the number of heating cycles, producing high-quality, three-dimensional(3D) glass artworks is feasible, even for large-scale projects. In addition, the microwave kiln can be used as an effective cooling tool to uniformly cool the formed casting glass. This study presents a possible alternative to conventional kiln technology and marks a paradigm shift in glassmaking, offering a more accessible and sustainable avenue for artists and practitioners.

Investigation on Dynamic Stability of Cement-Stabilized Expansive Soil Subgrades Subjected to Repeated Heavy-Haul Train Loads

The dynamic characteristics of the filler are intricately linked to the stability of the subgrade. In this investigation, relying on Haoji (Haolebaoji-Ji’an, China) heavy-haul railway engineering, cyclic triaxial tests were executed to scrutinize the dynamic attributes exhibited by the 3%–5% cement-stabilized expansive soil (CSES) across a series of diverse cyclic stress, confining pressures, and frequencies. Concurrently, in situ vibration trials were undertaken to dissect the dynamic characteristics inherent to the CSES subgrade. The outcomes of cyclic triaxial tests indicate that the augmentation in both the dynamic shear strength and modulus of CSES by a factor of 2–3, coupled with an escalation of the critical dynamic stress threshold by five tosix times, is attributed to the heightened internal structural density within the CSES compared to virgin expansive soil. In identical settings, it is noteworthy that the mean critical dynamic stress threshold observed for CSES surpasses that of Group A filling by a factor of 1.5–1.7. Furthermore, the maximum critical dynamic stress exhibited by CSES achieves a 1.2-fold superiority over its lime-stabilized expansive soil (LSES). The outcomes gleaned from the in situ vibration tests elucidate that, when subjected to the passage of a high-velocity train traveling at 120 km/hr, bearing the load of 25–30 tons per axle, the subgrade surface exhibits dynamic stress ranging from 98.57 to 116.07 kPa. Meanwhile, the dynamic stress undergoes a notable escalation due to rainfall infiltration, intensifying by a factor of 1.02–1.28 times its original magnitude. The influence depth of dynamic stress extends 1.4–1.6 times beyond the designed subgrade bed thickness of 2.5 m. Notably, the critical dynamic stress of the filler surpasses the dynamic stress at the same position, underscoreing the capacity of 3%–5% CSES filling for heavy-haul railways to ensure long-term dynamic stability.

Local correlations for predicting the transition process in separated flows tuned with a large experimental database

This work provides new correlations based on local variables for characterizing the transition process developing in the case of separated flows. The goal is to improve the capability of correlation-based transition models through the use of local variables. This may indeed simplify the implementation of the correlations into modern numerical codes, especially dealing with parallel computation and unstructured meshes. A large experimental database considering about 90 different flow conditions has been used to tune the present correlations. The database accounts for the variation of the flow Reynolds number, the free-stream turbulence intensity and the adverse pressure gradient affecting the boundary layer developing over a flat plate. The parameter variation induces the formation of both short and long laminar separation bubbles. The vorticity Reynolds number, based on the second invariant of the vorticity tensor, has been used as the main local variable for the activation of the transition process. Since it is proportional to the momentum thickness Reynolds number at the separation position, the vorticity Reynolds number (local) can be used in place of its counterpart based on the momentum thickness (integral), which is the variable usually adopted for activation of transition. Then, correlations providing a critical threshold for the vorticity Reynolds number promoting transition are tuned, for both short and long bubbles. These may be used into transition models to directly provide the location where the turbulence production needs to be activated. The proposed correlations have been validated using a second database not adopted for tuning and finally tested with data concerning a separated flow case in a low-pressure turbine cascade.

Hydro-sedimentological drivers of fine sediment ingress in a gravel-bed river

Most studies investigating fine sediment ingress in gravel-bed rivers have been conducted at the laboratory scale, and even fewer have explored the ingress processes of flocculated particles. Here, an extensive in-situ sampling programme was undertaken to investigate hydro-sedimentological drivers of interstitial fine sediment accumulation and to evaluate fine sediment ingress directional mechanisms in a gravel-bed river located on the eastern slopes of the Rocky Mountains in southern Alberta. Three sediment trap designs were installed across seven deployment cycles at four sites along the river. Instantaneous discharge, suspended solids concentration, and particle size distributions (of suspended and ingressed particles) were measured, while relevant hydraulic parameters were modelled with a flow model (MOBED). Distinct patterns of ingress dynamics between non-cohesive and cohesive fractions of fine sediment were observed. While the assessed hydro-sedimentological parameters did not statistically explain the ingress rates of non-cohesive 0.5 – 2 mm particles, the opposite was observed for < 0.5 mm particles, which were mostly transported in flocculated form. For flocculated sediment, horizontal ingress accounted for ∼ 60 % of interstitial accumulation. Directional ingress mechanisms, however, were dependent on flow conditions for both particle size fractions, with vertical and horizontal accumulations becoming more important during higher and lower energy flows, respectively. Our observations demonstrate the importance of ingress for the interstitial accumulation of fine sediment, even during events with flow above the critical threshold conditions for fine sediment gravitational deposition. Despite the comparable ingress rates to other studies, no interstitial clogging was observed in this study, demonstrating the channel potential storage capacity, which has implications for legacy impacts from landscape disturbances in the Crowsnest River catchment.

In-vivo characterization of scleral rigidity in myopic eyes using fundus-pulsation optical coherence elastography

The sclera plays an important role in the structural integrity of the eye. However, as myopia progresses, the elongation of the eyeball exerts stretching forces on the posterior sclera, which typically happens in conjunction with scleral remodeling that causes rigidity loss. These biomechanical alterations can cause localized eyeball deformation and vision impairment. Therefore, monitoring scleral rigidity is clinically important for the management and risk assessment of myopia. In this study, we propose fundus pulsation optical coherence elastography (FP-OCE) to characterize posterior scleral rigidity in living humans. This methodology is based on a choroidal pulsation model, where the scleral rigidity is inversely associated with the choroidal max strain obtained through phase-sensitive optical coherence tomography (PhS-OCT) measurement of choroidal deformation and thickness. Using FP-OCE, we conducted a pilot clinical study to explore the relationship between choroidal strain and myopia severity. The results revealed a significant increase in choroidal max strain in pathologic myopia, indicating a critical threshold beyond which scleral rigidity decreases significantly. Our findings offer a potential new method for monitoring myopia progression and evaluating therapies that alter scleral mechanical properties.

Hydrological responses of pine needle litter to rainfall erosional processes on Chinese karst hillslopes

Native vegetation restoration, such as pines, is an effective measure for mitigating soil erosion. However, the impact of pine needle litter on runoff, soil erosion, and hydrological responses on karst hillslopes remains unclear. This study investigated these factors during the rainy season from June to August 2021 under six distinct treatments (flat, gentle, and steep slopes with and without pine needle coverings). The results showed that pine needle litter significantly increased the soil water content, particularly on steeper slopes, by improving the water-holding capacity. It also substantially reduced runoff (by 23.8%) and soil erosion (by 92.5%). The critical rainfall threshold for generating runoff did not occur in the pine needle covering treatment, whereas it was 19.3 ± 8.8 mm in the bare soil treatment under wet conditions. These findings highlight the efficacy of pine needle cover in mitigating runoff and soil erosion in karst areas, suggesting it as a sustainable alternative against erosion, and underscoring the importance of pine plantations in degraded soil restoration efforts.

A non-linear relationship between blood pressure and mild cognitive impairment in elderly individuals: A cohort study based on the Chinese longitudinal healthy longevity survey (CLHLS).

Hypertension is an established risk factor for mild cognitive impairment (MCI) in elderly individuals. Nevertheless, the impact of different levels of blood pressure on the progression of MCI remains uncertain. This study aims to investigate the non-linear relationship between blood pressure and MCI in the elderly and detect the critical blood pressure threshold, thus, improving blood pressure management for individuals at high risk of MCI. Data was obtained from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) cohort. We chose normal cognitive elderly individuals who entered the cohort in 2014 for a 5-year follow-up to observe the progression of MCI. Subsequently, we utilized the Cox regression model to identify risk factors for MCI and conducted a Cox-based restricted cubic spline regression (RCS) model to examine the non-linear relationship between systolic blood pressure (SBP) and diastolic blood pressure (DBP) with MCI, determining the critical blood pressure threshold for MCI progression. In the elderly population, female (HR = 1.489, 95% CI: 1.017-2.180), lacking of exercise in the past (HR = 1.714, 95% CI: 1.108-2.653), preferring animal fats (HR = 2.340, 95% CI: 1.348-4.061), increased age (HR = 1.061, 95% CI: 1.038-1.084), increased SBP (HR = 1.036, 95% CI: 1.024-1.048), and increased DBP (HR = 1.056, 95% CI: 1.031-1.081) were associated with MCI progression. After adjusting factors such as gender, exercise, preferred types of fats, and age, both SBP (P non-linear < 0.001) and DBP (P non-linear < 0.001) in elderly individuals exhibited a non-linear association with MCI. The risk of MCI rose when SBP exceeded 135mmHg and DBP was in the range of 80-88mmHg. However, when DBP exceeded 88mmHg, there was a declining trend in MCI progression, although the HR remained above 1. The identified critical blood pressure management threshold for MCI was 135/80mmHg. In this study, we discovered that risk factors affecting the progression of MCI in elderly individuals comprise gender (female), preferring to use animal fat, lack of exercise in the past, increased age, increased SBP, and increased DBP. Additionally, a non-linear relationship between blood pressure levels and MCI progression was confirmed, with the critical blood pressure management threshold for MCI onset falling within the prehypertensive range.

Solar Influences on Winter Atmospheric Circulation Over the Ural, North Atlantic and North Pacific Regions: Pitchfork‐Like Relationships

AbstractLi's previous study found a one‐to‐two correspondence relationship between the total solar irradiance (TSI) and monthly anomalies of the Ural atmospheric circulation during winter months. This relationship roughly meets the so‐called supercritical pitchfork bifurcation model, hence termed a pitchfork‐like (PL) relationship. Here, we extend this study and provide more evidence to support previous findings. By analyzing data from 192 winter months and estimating the joint probability density function, we find that over the Ural, North Atlantic, and North Pacific regions, there are all PL relationships between the TSI and geopotential height anomalies at pressure levels no higher than 700 hPa. When the TSI gradually decreases and passes a critical threshold of 1360.9 W m−2, the preferred circulation patterns undergo a regime transition from one regime to two others. When TSI &lt; 1360.9 W m−2, positive and negative geopotential height anomalies occur at nearly equal frequencies within the same TSI range. This quantitative relation is met in almost the whole troposphere in each region. We suggest that the occurrence of PL relationships may be associated with the interaction between the westerly flow and topographic barriers; The decrease in TSI can regulate this interaction by reducing the stability of background westerly flow over all three regions, via increasing the land‐ocean thermal contrast and altering the planetary wavenumber‐2 wave at the mid‐high latitudes. Our work highlights the same quantitative relation between the TSI and the monthly mean geopotential height anomalies of three regions in winter, which has important implications for seasonal climate prediction.

Numerical Investigation of Heat Transfer and Development in Spherical Condensation Droplets

This study establishes thermodynamic assumptions regarding the growth of condensation droplets and a mathematical formulation of droplet energy functionals. A model of the gas–liquid interface condensation rate based on kinetic theory is derived to clarify the relationship between condensation conditions and intermediate variables. The energy functional of a droplet, derived using the principle of least action, partially elucidates the inherent self-organizing growth laws of condensed droplets, enabling predictive modeling of the droplet’s growth. Considering the effects of the condensation environment and droplet heat transfer mechanisms on droplet growth dynamics, we divide the process into three distinct stages, marked by critical thresholds of 105 nm3 and 1010 nm3. Our model effectively explains why the observed contact angle fails to reach the expected Wenzel contact angle. This research presents a detailed analysis of the factors affecting surface condensation and heat transfer. The predictions of our model have an error rate of less than 3% error compared to baseline experiments. Consequently, these insights can significantly contribute to and improve the design of condensation heat transfer surfaces for the phase-change heat sinks in microprocessor chips.

Predictive Value of Microfilariae-Based Stop-MDA Thresholds After Triple Drug Therapy With IDA Against Lymphatic Filariasis in Treatment-Naive Indian Settings.

Mass drug administration (MDA) of antifilarial drugs is the main strategy for the elimination of lymphatic filariasis (LF). Recent clinical trials indicated that the triple-drug therapy with ivermectin, diethylcarbamazine, and albendazole (IDA) is much more effective against LF than the widely used two-drug combinations (albendazole plus either ivermectin or diethylcarbamazine). For IDA-based MDA, the stop-MDA decision is made based on microfilariae (mf) prevalence in adults. In this study, we assess how the probability of eventually reaching elimination of transmission depends on the critical threshold used in transmission assessment surveys (TAS-es) to define whether transmission was successfully suppressed and triple-drug MDA can be stopped. This analysis focuses on treatment-naive Indian settings. We do this for a range of epidemiological and programmatic contexts, using the established LYMFASIM model for transmission and control of LF. Based on our simulations, a single TAS, one year after the last MDA round, provides limited predictive value of having achieved suppressed transmission, while a higher MDA coverage increases elimination probability, thus leading to a higher predictive value. Every additional TAS, conditional on previous TAS-es being passed with the same threshold, further improves the predictive value for low values of stop-MDA thresholds. An mf prevalence threshold of 0.5% corresponding to TAS-3 results in ≥95% predictive value even when the MDA coverage is relatively low.

Thermal Effects of 445 nm Laser Irradiation on the Bovine Tongue Tissues Ex Vivo

The purpose of this study was to employ the use of thermographic techniques to compare temperature changes and thermal heat transfer patterns in soft tissues when using the 445nm-diode laser with initiated and non-initiated tips. Methods: Bovine tongue slices measuring 5 mm in thickness were placed in between two microscopy glass slides at a distance of 11 cm from a thermographic camera. Fifteen 2 cm long incisions were made along the surface of the soft tissue parallel to the glass slides and the camera capture field. Incisions were performed using a 445nm diode laser (continuous wave at 2 watts) with 320μm-thick glass initiated and non-initiated fiber tips for a total 30-second irradiation period. The maximum temperature changes in oC (ΔT) in the soft tissues, as well as the vertical and lateral heat transfer (in mm), were recorded at 10-second intervals for a duration of 30 seconds, using the thermographic images captured using the infrared camera and a special image analysis software. Descriptive statistical analysis occurred to evaluate the temperature changes over the critical temperature threshold. Results: The maximum ΔT in oC for the initiated lasers was 17.48 ± 9.05 and for non-initiated lasers was 10.72 ± 2.29. The heat transfer in the two groups for vertical/lateral was 7.50 ± 1.4/18.30 ± 4.01 for the initiated lasers and 7.10 ± 1.82/19.24 ± 3.86 for the non-initiated lasers. Conclusion: Initiated tips and non-initiated tips of 445nm laser present deep penetration depths and high temperatures in bovine homogenous soft tissues. The irradiation period and clinical indication must be strictly followed to avoid complications from overheating in soft tissues.