Exponential Pattern Research Articles

System dynamics kinetic model for predicting biogas production in anaerobic condition: Preliminary assessment.

This preliminary assessment of a grey-box model, was predicated on system dynamics principles and developed using Vensim® DSS software. The purpose is to predict biogas production under anaerobic conditions for energy utilization at the design stage. To describe the process of a developed system dynamics model to predict biogas production under anaerobic conditions. This method involves two-stage kinetics of the biogas production process in anaerobic conditions using the first-order and Gompertz functions. The model is depicted in two parts: causal loop diagram and stock-flow diagram. The causal loop diagram describes the anaerobic digestion process a substrate undergoes for the production of biogas, while stock-flow diagram depicts basic building blocks of the dynamic behavior of an anaerobic digestion process. Primary data is from a laboratory-scale experiment of biogas production using vegetal wastes, while the secondary one is from the literature on studies using similar substrates. Primary and secondary data are used to validate and stimulate the developed model. The kinetic model shows the substrate being reduced exponentially with increasing time; consumption of substrate and production of methane and carbon dioxide follows exponential growth and decay pattern, with carbon dioxide production starting early compared to methane, and was produced at a rate faster due to the strong and resilient characteristics of fermentative microorganisms. Comparing data from empirical and model simulation shows some close relationship, though not too perfectly. Both results reflect signs of inhibitions occurring within the substrates in the digester under anaerobic conditions explaining the low methane yield or instability.

Age-related magnetic susceptibility changes in deep grey matter and cerebral cortex of normal young and middle-aged adults depicted by whole brain analysis.

Iron accumulates in brain tissue in healthy subjects during aging. Our goal was to conduct a detailed analysis of iron deposition patterns in the cerebral deep grey matter and cortex using region-based and whole-brain analyses of brain magnetic susceptibility. Brain MRI was performed in 95 healthy individuals aged between 21 and 58 years on a 3T scanner. MRI protocol included T1-weighted (T1W) magnetization-prepared rapid acquisition with gradient echo images and 3D flow-compensated multi-echo gradient-echo images for quantitative susceptibility mapping (QSM). In the region-based analysis, QSM and T1W images entered an automated multi-atlas segmentation pipeline and regional mean bulk susceptibility values were calculated. The whole-brain analysis included a non-linear transformation of QSM images to the standard MNI template. For the whole-brain analysis voxel-wise maps of linear regression slopes β and P values were calculated. Regional masks of cortical voxels with a significant association between susceptibility and age were created and further analyzed. In cortical regions, the highest increase of susceptibility values with age was found in areas involved in motor functions (precentral and postcentral areas, premotor cortex), in cognitive processing (prefrontal cortex, superior temporal gyrus, insula, precuneus), and visual processing (occipital gyri, cuneus, posterior cingulum, fusiform, calcarine and lingual gyrus). Thalamic susceptibility increased until the fourth decade and decreased thereafter with the exception of the pulvinar where susceptibility increase was observed throughout the adult lifespan. Deep grey matter structures with the highest increase of susceptibility values with age included the red nucleus, putamen, substantia nigra, dentate nucleus, external globus pallidus, caudate nucleus, and the subthalamic nucleus in decreasing order. Accumulation of iron in basal ganglia follows a linear pattern whereas in the thalamus, pulvinar, precentral cortex, and precuneus, it follows a quadratic or exponential pattern. Age-related changes of iron content are different in the pulvinar and the rest of the thalamus as well as in internal and external globus pallidus. In the cortex, areas involved in motor and cognitive functions and visual processing show the highest iron increase with aging. We suggest that the departure from normal patterns of regional brain iron trajectories during aging may be helpful in the detection of subtle neurodegenerative and neuroinflammatory processes.

Shortcomings of NPV Calculation: Does One Error Annul the Other?

The research aims at analyzing the aggregate effect of possible errors related to the "textbook" method of present value calculation. Two main errors could stem from end-of-period convention and calculation according to expected lifespan. The magnitude of such errors depends on the cash flow pattern and the probability distribution of asset life, therefore the combination that may be regarded as the most typical in practice has been chosen as the subject of the examination, i.e., the continuous exponential cash flow pattern with exponentially distributed life. Based on the result of previous studies examining the errors separately, it seems possible that the two errors lead to a more accurate approximation – considering the absolute value of the relative error – compared to making only one of the errors. After the examination, I conclude that in the most typical cases of practice, it is not worth to take either the correct cash flow pattern or the life uncertainty into account beyond the "textbook" method.

Temporal trajectory of biofluid markers in Parkinson\u2019s disease

Full dynamics of biofluid biomarkers have been unknown in patients with Parkinson’s disease (PD). Using data from 396 PD patients and 182 controls in the Parkinson's Progression Markers Initiative (PPMI) database, we estimated long-term temporal trajectories of CSF α-synuclein (α-syn), amyloid-β (Aβ), total tau (t-tau), phosphorylated tau (p-tau) and serum neurofilament light chain (NfL) by integrating function between the baseline levels and annual changes. At baseline, PD patients showed lower CSF α-syn, Aβ, t-tau and p-tau levels than those of the controls. In all PD patients, CSF α-syn and Aβ decreased in a negative exponential pattern before the onset of motor symptoms, whereas CSF t-tau and p-tau, and serum NfL increased. Patients with cognitive impairment exhibited faster decline of Aβ and α-syn and faster rise of t-tau, p-tau and NfL, when compared to those without. Similarly, low Aβ group showed earlier decline of α-syn, faster rise of t-tau, p-tau and NfL, and faster decline of cognitive performances, when compared to high Aβ group. Our results suggest that longitudinal changes in biomarkers can be influenced by cognitive impairment and Aβ burden at baseline. PD patients with Aβ pathology may be associated with early appearance of α-synuclein pathology, rapid progression of axonal degeneration and neurodegeneration, and consequently greater cognitive decline.

Floodplain forest structure and the recent decline of Carya illinoinensis (Wangenh.) K. Koch (northern pecan) at its northern latitudinal range margin, Upper Mississippi River System, USA

Floodplain hardwood forests that exist on islands and immediately adjacent to channels along the Upper Mississippi River System (UMRS) are ecologically important due to high floral and faunal biodiversity. The recent decline and regeneration failure of hard mast species—e.g. Quercus spp. and Carya spp.—along the UMRS has been well documented, but causes of these trends have not been widely examined and are thus poorly understood. To investigate the mechanisms of this decline, we installed three 0.20-ha plots within the floodplain forests of the UMRS amongst communities known to contain the northernmost documented individuals of Carya illinoinensis (Wangenh.) K. Koch, a regionally imperiled, yet ecologically, economically, and culturally important hard mast species. Tree density (>5 cm dbh) averaged 355 stems ha−1 (n = 239, 12 representative species across 9 genera) and mean basal area was 77 m2 ha−1 across the three sites. Acer saccharinum L. was the most dominant species (49.0 m2 ha−1). The diameter distribution of trees demonstrated a negative exponential pattern, generally indicative of uneven-aged, regenerating forests. Over the past ca. 120 years, decadal-scale pulses of tree establishment across species show linkages with riparian engineering installments and flood and drought events. C. illinoinensis demonstrated a consistent establishment pattern since at least the 1860s through the 1950s, but experienced regeneration failure over the past ca. 50 years. Widespread ecological growth releases in C. illinoinensis are linked with known large-scale flood events along the UMRS (1965, 1993, 2001, 2011 CE). Correlation analysis revealed relationships between C. illinoinensis growth rings and drought, precipitation, maximum temperature, and river flow to be temporally unstable with an inflection point at the beginning of the lock and dam era (ca. 1930s–1940s). The coincidental decoupling of climate and flow variability with tree growth in the post-lock and dam era suggests that peripheral, disjunct populations of C. illinoinensis are sensitive to impacts from anthropogenic land and hydrologic modifications. Forest structure, disturbance history, and climate analyses demonstrate that without management intervention, C. illinoinensis will no longer have a significant presence within floodplain forests of the UMRS in the near future, contributing to loss in diversity. Direct forest restoration techniques, such as planting and creation of canopy gaps via regeneration-focused harvesting, are needed if C. illinoinensis is to return to historical abundance and distribution.

How Common Is the Exponential Decay Pattern of Motor Skill Acquisition? A Brief Investigation.

Motor performance is classically described as improving nonlinearly with practice, demonstrating rapid improvements early in practice with stabilization later, which is commonly modeled by exponential decay functions. However, retrospective analyses of our previously collected data challenge this theoretical model of motor skill acquisition, suggesting that a majority of individual learners actually demonstrate patterns of motor improvement different from this classical model. A convenience sample of young adults, older adults, and people with Parkinson disease trained on the same functional upper-extremity task. When fitting three-parameter exponential decay functions to individual participant data, the authors found that only 13.3% of young adults, 40.9% of older adults, and 66.7% of adults with Parkinson disease demonstrated this "classical" skill acquisition pattern. Thus, the three-parameter exponential decay pattern may not well-represent individuals' skill acquisition of complex motor tasks; instead, more individualized analysis methods may be warranted for advancing a theoretical understanding of motor skill acquisition.

Modeling Treatment Response to Transcranial Magnetic Stimulation Using an Exponential Decay Function

Pharmacological depression treatments demonstrate a nonlinear pattern of symptom response, where the largest reduction in symptoms is observed within the first weeks followed by smaller improvements. This study investigated whether this exponential pattern could also model the antidepressant response to therapeutic transcranial magnetic stimulation (TMS).

Age-related expression of prominent regulatory elements in mouse brain: catastrophic decline of FOXO3a.

Aging is associated with changes in regulation, particularly among diverse regulators in the brain. We assayed prominent regulatory elements in mouse brain to explore their relationship to one another, stress, and aging. Notably, unphosphorylated (activated) forkhead transcription factor 3a (uFOXO3a) expressed exponential decline congruent with increasing age-related mortality. Decline in uFOXO3a would impact homeostasis, aging rate, stress resistance, and mortality. We also examined other regulators associated with aging and FOXO3a: protein kinase B (PKB), the mechanistic target of rapamycin (mTOR), 70kDa ribosomal S6 kinase (P70S6K), and 5' AMP-activated protein kinase (AMPK). It would require powerful regulatory distortion, conflicting tradeoffs and/or significant damage to inflict exponential decline of a transcription factor as crucial as FOXO3a. No other regulator examined expressed an exponential pattern congruent with aging. PKB was strongly associated with decreases in uFOXO3a, but the aging pattern of PKB did not support a causal linkage. Although mTOR expressed a trend for age-related increase, this was not significant. We considered that the mTOR downstream element, P70S6K, might suppress FOXO3a, but remarkably, it expressed a strong positive association. The age-related pattern of AMPK was also incompatible. Literature suggested the immunological regulator NFĸB (nuclear factor kappa-light-chain-enhancer of activated B cells) increases with age and suppresses FOXO3a. This would inhibit apoptosis, autophagy, mitophagy, proteostasis, detoxification, antioxidants, chaperones, and DNA repair, thus exacerbating aging. We conclude that a key aspect of aging involves distortion of key regulators in the brain.

Mathematical pattern of Kessler psychological distress distribution in the general population of the U.S. and Japan

BackgroundAlthough the 6-item Kessler psychological scale (K6) is a useful depression screening scale in clinical settings and epidemiological surveys, little is known about the distribution model of the K6 score in the general population. Using four major national survey datasets from the United States and Japan, we explored the mathematical pattern of the K6 distributions in the general population.MethodsWe analyzed four datasets from the National Health Interview Survey, the National Survey on Drug Use and Health, and the Behavioral Risk Factor Surveillance System in the United States, and the Comprehensive Survey of Living Conditions in Japan. We compared the goodness of fit between three models: exponential, power law, and quadratic function models. Graphical and regression analyses were employed to investigate the mathematical patterns of the K6 distributions.ResultsThe exponential function had the best fit among the three models. The K6 distributions exhibited an exponential pattern, except for the lower end of the distribution across the four surveys. The rate parameter of the K6 distributions was similar across all surveys.ConclusionsOur results suggest that, regardless of different sample populations and methodologies, the K6 scores exhibit a common mathematical distribution in the general population. Our findings will contribute to the development of the distribution model for such a depression screening scale.

Endothelial Stromal PD-L1 Modulates CD8+ T Cell Infiltration after Heart Transplantation

Purpose Heart transplantation is the only definitive treatment for end-stage heart failure. The role of checkpoint axes in transplantation has been partially addressed in animal models, but not in humans. Occurrence of fulminant myocarditis with allorejection-like immunologic features in patients under anti-PD1 treatment suggests a key role of the PD-1/PD-L1 axis in cardiac immune homeostasis. Methods We cross-sectionally studied 23 heart transplant patients undergoing surveillance endomyocardial biopsy (EMB). EMB tissue and peripheral blood mononuclear cells (PBMC) were analyzed by flow cytometry. Multivariate logistic regression analyses including demographic, clinical and hemodynamic parameters were performed. Murine models were used to evaluate the impact of PD-L1 endothelial graft expression in allorejection. Results We found that myeloid cells dominate the composition of the graft leukocyte compartment in most patients, however with variable T cells frequencies that in few patients were the main infiltrating population. The CD4:CD8 T cells ratios were between 0 and 1.5. The proportion of PD-L1 expressing cells in graft endothelial cells, fibroblasts and myeloid leukocytes ranged from negligible up to 60%. We found a significant inverse correlation following an exponential decay pattern between a proportion of PD-L1+HLA-DR+ endothelial cells and proportion of CD8+ T cells. PD-L1 expression and leukocyte patterns were independent of demographic, clinical and hemodynamic parameters. We confirmed the importance of PD-L1 expression by endothelial cells in a murine model of fully allogeneic heart transplant. We found that Tie2Crepdl1fl/fl grafts lacking PD-L1 in endothelial cells were rejected significantly faster than Tie2Cre controls. Conclusion Loss of graft endothelial PD-L1 expression may play a permissive role toward CD8+ T cell infiltration in human heart transplantation. Murine model results suggest that indeed loss of graft endothelial PD-L1 may facilitates alloresponses, and thus potentially play a role in heart transplant rejection.

The impact of 10-valent pneumococcal conjugate vaccine upon hospitalization rate of children with pneumonia in different Brazilian administrative regions

BackgroundStreptococcus pneumoniae is the most frequent bacterial causative agent of pneumonia. Due to its significant contribution to the morbidity and mortality profile and the country’s economy, the 10-valent pneumococcal vaccine (PCV10) was introduced in Brazil in 2010. Brazil is divided into five administrative regions which differ in social-economic indices among each other. Estimates of PCV10 impact on hospitalization rates due to pneumonia stratified by distinct Brazilian regions are limited. We assessed this issue. MethodsThis is a population-based ecological investigation. Data about hospitalizations due to pneumonia, asthma or urinary tract infection (UTI) among patients aged under 20 years in the pre-exposure (2003–2009) and in the post-exposure (2011–2017) periods were retrieved from the National Health System – Hospital Information System (SIH-SUS) database. The total resident population by age group in each year was retrieved from the Brazilian Institute for Geography and Statistics database. Hospitalization rates were estimated for each Brazilian region and the rates obtained in the pre-exposure and in the post-exposure periods were compared by Prais-Winsten regression. The Human Development Index (HDI) evolved differently in the distinct regions during the study period. ResultsOverall, hospitalization rates due to pneumonia declined by 34.5%. Similar trends were observed for hospitalization rates due to asthma and UTI. The same pattern was observed in each Brazilian region. However, the North region was the only one that presented an exponential incidence decline pattern, which could be explained by PCV10 implementation (declined by 10.8% in the quadratic regression, p < 0.01). Only in the North region, significant decline was observed among patients aged 0–4 years (-12.5%; p = 0.01), 5–9 years (-38.5%; p < 0.01) or 10–14 years (-10.7%; p = 0.03). ConclusionSignificant variation in the downward trend of hospitalization rate was only found in the North region, which evolved from very low HDI in 2003; medium HDI in 2010 to high HDI in 2017.

An Optimal Compensation Agency Model for Sustainability under the Risk Aversion Utility Perspective

This paper explores how to construct a fair and optimal compensation system between the principal and the agent in the face of financial compensation agency problems during a limited period in relation to the concept of sustainability. In the construction of the principal’s compensation system, the agent’s degree of operational financial effort will affect the overall revenue function for reaching sustainability. Both the principal and the agent have a maximum expected utility in the negative exponential pattern of the general hyperbolic absolute risk aversion (HARA) utility function that satisfies their respective objective functions. The proposed model and numerical example analysis results prove that the compensation system for sustainability can provide a fair and optimal financial system, from a sustainability perspective. The main contribution of this study is the construction and development of an optimal compensation agency model for risk management, which is derived by considering the effect of risk aversion utility on revenue. The proposed model can provide a fair and feasible approach within the issue of compensation, from the viewpoint of sustainability, for an optimal compensation agency problem.

Abstract P472: Characterization of Infarct Growth Rate Patterns in Patients With Large-Vessel Occlusion Stroke Undergoing Mechanical Thrombectomy

Introduction: Infarct growth is affected by the collateral blood supply and ischemic tolerance and thus unlikely linear. This study aimed to better characterize infarct growth rates (IGR) after large-vessel occlusion (LVO) stroke. Methods: We retrospectively identified patients with anterior LVO stroke who underwent mechanical thrombectomy (MT) at two comprehensive stroke centers. Core infarct volumes at presentation (CBF&lt;30%) were estimated using RAPID software. Final infarct volume (FIV) was measured on post-MT MRI. We estimated IGR during two intervals: IGR 1 defined as CBF&lt;30% (ml) / Time from onset to CTP (hours); and IGR 2 as [FIV - CBF&lt;30% (ml)] / Time from CTP to reperfusion (hours). To calculate IGR 2, we only analyzed patients with successful MT (mTICI ≥ 2b) assuming no significant infarct growth after reperfusion. Functional outcome was assessed using the modified Rankin scale (mRS) at 90 days. We performed the Receiver-operating characteristic (ROC) analysis for each interval to best classify patients into slow and fast progressors. Results: Of the 361 patients (age 68 ± 15, 55% female, NIHSS 14 ± 6) included in the analysis, 282 (78.1%) had successful reperfusion, and 150 (41.6%) achieved a good outcome (mRS ≤2). IGR showed an exponential growth pattern (Figure 1). There was no significant difference in the median IGR 1 between the poor and good outcome groups (2.3 vs. 1 ml, p=0.061). The median IGR 2 in patients with poor outcome was significantly higher when compared to those in the good outcome group (IGR 14.1ml/h vs. 4.62ml/h, p&lt;0.0001). IGR 2 ≥ 12.2ml/h had a sensitivity of 0.56 and a specificity of 0.77 (AUC 0.67) for predicting poor outcome. Conclusions: We identified an exponential infarct growth pattern after LVO stroke that differs in relation to outcome. High IGR in the interval from CTP to reperfusion is associated with worse outcomes, emphasizing the importance of future research into therapeutic approaches to slow down infarct progression.

Implications of the COVID-19 Lockdown on Dengue Transmission in Malaysia.

We aim to investigate the effect of large-scale human movement restrictions during the COVID-19 lockdown on both the dengue transmission and vector occurrences. This study compared the weekly dengue incidences during the period of lockdown to the previous years (2015 to 2019) and a Seasonal Autoregressive Integrated Moving Average (SARIMA) model that expected no movement restrictions. We found that the trend of dengue incidence during the first two weeks (stage 1) of lockdown decreased significantly with the incidences lower than the lower confidence level (LCL) of SARIMA. By comparing the magnitude of the gradient of decrease, the trend is 319% steeper than the trend observed in previous years and 650% steeper than the simulated model, indicating that the control of population movement did reduce dengue transmission. However, starting from stage 2 of lockdown, the dengue incidences demonstrated an elevation and earlier rebound by four weeks and grew with an exponential pattern. We revealed that Aedes albopictus is the predominant species and demonstrated a strong correlation with the locally reported dengue incidences, and therefore we proposed the possible diffusive effect of the vector that led to a higher acceleration of incidence rate.

Seed longevity and seedling emergence behavior of wild oat (Avena fatua) and sterile oat (Avena sterilis ssp. ludoviciana) in response to burial depth in eastern Australia

AbstractWeed emergence time and the longevity of weed seeds within the soil play an important role in implementing a timely and effective weed control program. In this study, the seed longevity and emergence pattern of wild oat (Avena fatua L.) and sterile oat [Avena sterilis ssp. ludoviciana (Durieu) Gillet &amp; Magne] were monitored in field conditions. Fresh seeds of A. fatua and A. ludoviciana were placed into nylon bags (50 seeds per bag in three replications for three locations in eastern Australia: Gatton, Narrabri, and St George) and buried at depths of 0, 2, and 10 cm in November 2017. Bags were exhumed at 6-mo intervals over 30 mo to evaluate seed germination, viability, and decay components. The seed decay component of A. fatua and A. ludoviciana followed an exponential pattern. On both the surface and at the 10-cm burial depth, 50% of the seeds of A. fatua and A. ludoviciana had decayed by 6 mo. The seeds of A. fatua persisted longer at 2-cm depth than at other depths, particularly at St George, where 90% of the seeds decayed after the 30-mo study. However, at Gatton and Narrabri, 90% of the seeds of A. fatua at this depth had decayed after 18 mo of burial in the soil. In the emergence pattern experiment (2017 to 2019), the emergence of A. fatua and A. ludoviciana from different burial depths was also studied. The emergence of A. fatua and A. ludoviciana was greater from 2-cm (29% to 36%) and 5-cm (18% to 43%) soil depths compared with the surface (5% to 10%) and 10-cm (3-9%) soil depth. Avena ludoviciana emerged earlier (2,253 growing degree days [GDD]; March 14, 2018) than A. fatua (3,364 GDD; May 23, 2018). Both species exhibited high emergence between May to June 2018, and the last cohort of each species was observed in October 2018. The highest seedling emergence occurred at the start of the winter season (May), which emphasizes the need for early PRE weed control such as tillage, herbicide application, and cover crops to ensure crops are planted in a clean seedbed. The continued emergence of these weeds into the spring season (October) emphasizes the need for extended periods of A. fatua and A. ludoviciana management. The results also suggest that management strategies that can control all emerged seedlings over 2 yr and restrict seed rain in the field could lead to complete control of Avena spp. in the field.

Use of air-coupled ultrasound for the non-invasive characterization of the textural properties of pork burger patties

This study tests the feasibility of air-coupled ultrasound for the characterization of the textural properties of pork burger patties. The samples were prepared by mixing lard at different percentages (0, 20, 40, 60 and 80%) with a commercial burger meat mixture. Through-transmission airborne ultrasound measurements (250 kHz) were carried out at 5 and 20 °C. Ultrasonic velocity at 5 °C increased exponentially with fat content (r = 0.99), varying from 1587 to 1668 m/s, whereas it remained fairly constant at 20 °C (1644 to 1624 m/s). Ultrasonic attenuation decreased with fat content following an exponential pattern (r = −0.83 at 5 °C; r = −0.93 at 20 °C) and ranged from 62.6 to 44.8 Np/m at 5 °C, and from 76.7 to 42.2 Np/m at 20 °C. Noticeable correlations were found between hardness and ultrasonic velocity (r = 0.89 at 5 °C), and between Total Relaxation Capacity and ultrasonic attenuation (r = 0.89 at 5 °C; r = 0.99 at 20 °C). Additionally, airborne ultrasound allowed an accurate (mean relative difference 2.3%) prediction of burger thickness. • Air-coupled ultrasound was used for textural characterization of pork burger patties. • Ultrasonic velocity increases exponentially with fat content at 5 °C. • Ultrasonic attenuation decreases exponentially with fat content at 5° and 20 °C. • Textural parameters are correlated with ultrasonic velocity and attenuation at 5 °C. • Air-coupled ultrasound allows a contactless determination of burger patty thickness.

Exploring and quantifying the relationship between instantaneous wind speed and turbidity in a large shallow lake: case study of Lake Taihu in China.

Sediment resuspension is critical to the internal nutrient loading in aquatic systems. Turbidity is commonly used as an indicator for sediment resuspension and is proved to be highly correlated to wind speed in large shallow lakes. A field observation of wind speed and turbidity was conducted using a portable weather station and a YSI 6600V2-2, and an observation lasting for 39days was evaluated in this study (the data points with wind speed > 4m/s account for 75%). The daily average values (DA dataset) as well as daily maximum (MX dataset) and minimum values (MI dataset) were calculated from the instantaneous observations (IN dataset). Correlations in IN dataset were deduced based on machine learning methods and were compared to those obtained from DA, MI, and MX datasets. Furthermore, the correlation in IN dataset was analyzed by using two statistical methods, and from the view of statistical the turbidity is regarded as a variable. Results indicate that the correlations in IN datasets follow the exponential function or power function pattern with a critical wind speed of 6m/s, Regression on IN dataset revealed that linear regression model had the best performance on predicting the turbidity in test dataset and no significant differences are observed between exponential function and power function pattern. Correlations in DA and MX datasets exhibit higher maximal information coefficient (MIC) than IN dataset and error of turbidity prediction introduced by using these correlations in IN dataset is within the tolerance level. Statistical analysis on the IN dataset shows that a strong relationship exists among the wind speed and expectation of turbidity with a MIC over 0.99, and follows the exponential function or the power function as well with a different critical wind speed of 4m/s. Over 95% data points fall in the predicted intervals of turbidity for both methods, suggesting a high predicting accuracy.

Forecasting the Number of Coronavirus (COVID-19) Cases in Ethiopia Using Exponential Smoothing Times Series Model

Coronavirus, also known as COVID-19 was first originated in Wuhan, Hubei province in China around December 2019 andspread out all over the world within few weeks. Following the outbreak, the World Health Organization (WHO) declares the outbreak as pandemic on 11 March 2019. The coronavirus (COVID-19) have a fast transmission nature and grow exponentially across the globe. Subsequently, to model the exponential growing nature of the virus, different researchers conducted their study using a linear based time series (such as ARMA family) models. However, such linear time series models cannot handle data having an exponential growing pattern. Since linear based time series models cannot handle a data having an exponential growing pattern, we applied the common exponential family models such as an Exponential Growth Model, Simple Exponential Smoothing (SES), and Double Exponential Smoothing (DES) methods in Ethiopia from March 14, 2020 to June 05, 2020. The results of the study showed that double exponential smoothing methods was appropriate in forecasting the future number of COVID-19 cases in Ethiopia as dictated by lowest value of root mean sum of square error. The forecasting model shows that the number of coronavirus cases in Ethiopia grows exponentially. In general, the forecast helps the Ethiopian government, policy makers, and the society at all to take preventive measures before the transmission become out of control especially rural areas since until now, most of the cases were observed in urban areas.

Overdiagnosis of thyroid cancer

Overdiagnosis is the main «driver» of the growing epidemic of thyroid cancer in the world. More than half of cases of thyroid cancer in women are the result of overdiagnosis, i.e. diagnosis of a tumor, the probability of progression and metastasis of which is extremely low. Our analysis showed that the incidence of thyroid cancer in Russia and most of its administrative regions is growing. At the same time, we observe pronounced interregional variability in the incidence rate. A very highage adjusted incidence rate, especially among women, is registered in the Bryansk region and other high-risk regions. The main cause of the increase in the incidence of thyroid cancer in the regions adjacent to the Chernobyl nuclear power plant is exposure to radioactive iodine (131I ) in childhood and adolescence. However, an increase in the incidence of thyroid cancer in this region at least partly is a consequence of ultrasonography (US) screening and the identification of clinically insignificant lesions. Only 40% of cases of thyroid cancer detected as a result, of screening could be the attributed to radiation. Accordingly, 60% are latent tumors that would never have clinically shown themselves if they had not been identified as a result, of screening.Altai region is also considered a high-risk region because it borders with the Semipalatinsk region of Kazakhstan the region where the former Soviet nuclear test site was located. Inthe Altai region, the introduction of US screening led to an increase in the detection of thyroid cancer from 8,7% in 1992 to 20,3% in 1999. A marked increase in incidence in Russia, the increase in incidence in middle age and as a result the change in expected exponential pattern of age-specific curve into inverted «U», a very high incidence to mortality ratio, a very high cancer survival rate, which statistically significantly correlates with incidence, a statistically significant correlation between the proportion of tumors detected at the first stage and the incidence of thyroid cancer, a statistically significant correlation between prevalence of thyroid cancer and the incidence is a clear evidence of overdiagnosis. We estimate that the number of overdiagnosed thyroid cancer in Russia over 27 years ranges from 99000 to 138000 cases. We do not have sufficient retrospective data to estimate more accurately the size of thyroid cancer overdiagnosis in Russia. Thyroid cancer incidence data for Russia overall is available only from 1989.

Indirect assessment of internal irradiation from tritium decay on Lemna Minor duckweed

The response changes of the specific growth rate of Lemna minor duckweed was modeled using the logarithms of frond numbers on tritium activity concentration and gamma radiation dose from cobalt 60. The concept of average specific growth rate depends on the general exponential growth pattern, where toxicity is estimated based on the effect on the growth rate. One of the main questions of the effect of the radiation dose on duckweed is how to correlate the effect of beta radiation with the effect of any other radiation for modeling radiation on Lemna minor. Experimental data were extrapolated by utilizing the OECD guidelines.A linear relationship of absorbed dose and activity concentration was obtained for the average dependency growth rate of Lemna minor as D = (0.1257) · A0.585. The dose rate of gamma irradiation from 60Co increases with tritium activity dependence, on the specific growth rate of the Lemna minor duckweed. An increase in the tritium activity causes a decrease in the specific growth rate of the Lemna minor duckweed. It indicates that as the quantity of the beta radiation dose increase in Lemna minor duckweed, a higher quantity of gamma radiation will be required to cause the same effect in the specific growth rate of Lemna minor duckweed. The relation between the inhibition of the Lemna minor seedling growth and gamma and beta radiation dosage agrees roughly with that between the decrease of survival rate or fertility and dosage.