Lack Of Linearity Research Articles

Machine Learning Based Fault Classification in Pilot Plant Batch Reactor: Using Support Vector Machine.

Identifying and diagnosing faults is a critical task in process industries to maintain effective monitoring of process and plant safety. Minimizing process downtime is critical for enhancing the quality of the product and minimizing production costs. Real-time categorization of issues across several levels is essential for the monitoring of processes. However, there are still notable obstacles, that must be addressed, such as the existence of robust correlations, the complexity of the data, and the lack of linearity. This study introduces a novel fault identification technique in batch reactor experimental trials that employs multikernel support vector machines (SVMs) to categorize internal and external issues, specifically reactor temperature, coolant temperature, and jacket temperature. The data set was obtained from empirical research. The classification has been conducted using a multikernel SVM. This article identified that the nonlinear classifier using the radial bias function results in an accuracy that is at least 22.08% superior to other methods.

Method PPC for Precise Piecewise Correlation after Histogram Segmentation

Correlation, functioning as a symmetric relation, is very powerful indicator of the mutual association between two attributes. The problem of weak correlation indicates a lack of linearity in the observed range. This paper presents the precise piecewise correlation method, which overcomes the problem by determining the segments where the linear association will be present. The determination was achieved using the histogram segmentation method. The conditions of the application and analysis of the method are presented, as well as the application of the method to the representative datasets. The obtained results confirm the existence of stronger linear associations on the segments. Detected correlations reveal the strength and nature of the symmetric association between two attributes on each of the separated segments.

Presence of macroproteins on the measurement of vitamin B12: studying high vitamin B12 levels using polyethylene glycol and heterophile antibody blocking tubes

Immune methods are measurement systems that can be affected by interference. The interfering substance may be endogenous immunoglobulins, antibodies, analyte-antibody complexes, and heterophile antibodies. In our study, we aimed to investigate the effect of macrovitamin B12 on high vitamin B12 levels measured using immune methods. Among the serum samples studied in our laboratory; serum from 145 individuals was determined as the patient group and serum from 50 individuals was determined as the control group. We investigated the effect of macroprotein on B12 measurement by using polyethylene glycol (PEG) precipitation, heterophile antibody blocking tube (HBT) and serial dilution methods. According to the recovery evaluation and the modified reference range evaluation after precipitation with PEG, the macrovitamin B12 percentage in the patient group was 58 (40%) and 65 (44.8%), respectively. There was no decrease in vitamin B12 values after the study with HBT. A lack of linearity was observed in 23 (18.7%) of 123 sera with serial dilution method. Macrovitamin B12 should be considered as a differential diagnosis of unexpectedly high vitamin B12 levels. According to the results of our study, we think that it would be appropriate to precipitate with PEG first when there is a suspicion of macrovitamin B12. In collaboration with clinical and laboratory, we recommend that the patient’s clinical status and additional laboratory findings be examined, and the patient’s sample should be evaluated and interpreted by a specialist in biochemistry by selecting the appropriate interference detection method.

142 Heart rates at the trot on a mechanical walker are correlated to cardiovascular fitness in Thoroughbred racehorses

The relationship between heart rate (HR) and velocity under saddle or on a treadmill can be used to estimate cardiovascular fitness in horses. Whether HR data gathered during other types of exercise can be used to estimate fitness is unknown. This study hypothesized that HR data collected on a mechanical walker could be used to estimate cardiovascular fitness in Thoroughbred racehorses (TBs), young horses having lower fitness with higher trotting HRs than older horses. Five, 2- and 3-year-old TBs (YOUNG) (2.2 ± 0.5 yr) and 5, 5- to 9-year-old TBs (MATURE) (6.6 ± 1.7 yr) were used. Four of the YOUNG horses had recently been prepped for 2-year-old in-training sales. MATURE horses had been in race training for over a year. During the 4-wk study, horses were exercised on a mechanical walker 3 d/wk. Exercise consisted of a 5-min warm-up walk (1.7 m/s), 15-min slow trot (2.7 m/s), and 5-min cool-down walk (1.7 m/s). HR data were collected from the walker during the final 10 min of the trot (HR trot ). All horses were also exercised on the racetrack 3 d/wk. The HR-velocity relationship during track exercise was determined using a Polar Ⓡ on-board HR monitor and KER ClockIt smartphone fitness app. Fitness was assessed by velocities (V) calculated at different HRs (V 160 , V 180 , and V 200 ) by linear regression. Differences between age groups were determined using unpaired t -tests. One walker session and one track session from each week were used from each horse to evaluate the relationship between HR trot and cardiovascular fitness via simple linear regression. All results are reported as mean ± SD. One YOUNG horse was excluded from analysis due to unsteady pace on the walker resulting in erratic HR trot . One MATURE horse was excluded from analysis due to excitability under saddle resulting in lack of linearity between HR and speed during track exercise. HR trot was lower for MATURE (77.3 ± 3.8 bpm) versus YOUNG (87.6 ± 4.5 bpm) ( P < 0.01). Speed differed between groups on the track at all HR levels (V 160 : MATURE: 7.3 ± 0.7 m/s, YOUNG: 6.3 ± 0.8 m/s ( P < 0.01); V 180 : MATURE: 9.2 ± 0.6 m/s, YOUNG: 8.0 ± 0.7 m/s ( P < 0.01); V 200 : MATURE: 11.1 ± 0.7 m/s, YOUNG: 9.7 ± 0.8 m/s ( P < 0.01)). HR trot and V 160 , V 180 , and V 200 were negatively correlated in both groups (V 160 R 2 = 0.44 ( P < 0.001); V 180 R 2 = 0.62 ( P < 0.001); V 200 R 2 = 0.66 ( P < 0.001)). These results suggest that cardiovascular fitness under saddle may be estimated from HR collected at a trot on a mechanical walker. It is unknown whether differences observed between groups’ cardiovascular fitness were due to age or previous degree of training.

직류 오프셋 제거 회로를 가진 저 전력 프로그램 가능한 이득 증폭기 설계

In this paper, a low-power gain control amplifier with a direct current offset cancellation circuit is proposed in order to amplify analog signals. The proposed PGA (Programmable Gain Amplifier) is less sensitive to external influences due to the inclusion of active load on differential amplifiers. The PGA connects a direct current offset cancellation circuit, based on the Miller effect, to a differential amplifier stage to reduce area and compensate for distortion or lack of linearity. This circuit is also designed to be adjustable in eight steps, from 4 dB to 60 dB, using gain controls. The proposed PGA is designed using the TSMC 0.13 μm CMOS process, and was verified by simulation in ADS (Advanced Design System) tool. Compared to conventional research results, the proposed PGA achieved a gain error of less than 0.1 dB and a lower consumption of 0.16 mW.

I misteriosi anni Venti. Lalla Romano e la Torino post-gobettiana

This essay proposes a reinterpretation of Lalla Romano’s novel, Una giovinezza inventata [An Invented Youth], published by Einaudi in 1979, depicting the author’s university experience in Turin in the second half of the 1920s. Weaving together literary studies along with historical accounts and surveys in art history, the essay reconstructs a unique period in time, one first spawned by Gramsci and to an even greater extent by Gobetti, which witnessed figures born and raised in Turin go on to play a decisive role in the political and cultural future of the country. Drawing from the historiographical debate on Turinese culture between the two World Wars by such scholars as Norberto Bobbio and Angelo d’Orsi, this essay incorporates textual analysis and examines historical and philological findings at work within the novel in order to reconstruct the unique context within which the pages of Una giovinezza inventata unfold - that mysterious antifascist Turinese setting of the 1920s, surprisingly unique owing to its lack of linearity. There emerges a portrait of various women (e.g. the young women of Casorati’s circle) and men (among whom Venturi, Soldati and Antonicelli) whom the narrative voice evokes in her recollections.

A resistência, de Julián Fuks: uma narrativa de filiação

Resumo Neste artigo explorarei o conceito de “narrativa de filiação”, de Dominique Viart, para analisar como Julián Fuks constrói sua relação com seus pais e irmãos e como as migrações dos ancestrais forjaram a família que veio parar em São Paulo durante a última ditadura militar na Argentina. Esse romance da era da pós-ficção aparece como testemunha do nosso tempo, testemunha dos horrores vivenciados por tantos humanos que perderam sua humanidade nos porões dos centros de tortura ou nos campos de extermínio durante a Segunda Guerra. Essa literatura de resistência se caracteriza pela ausência de linearidade, pela tensão entre o real e o ficcional, pela investigação, pelo recurso a hipóteses, plausíveis ou implausíveis, e pela preocupação com a questão social. Essa “escrita da restituição”, nas palavras de Viart, coloca em dúvida suas próprias investigações e desconfia de discursos e conceitos, recusa as ideias prontas e as verdades bem estabelecidas. A postura enunciativa é explicitada e o leitor sabe quem fala e de que lugar fala o narrador.

Pre-calculated duty cycle optimization method based on genetic algorithm implemented in DSP for a non-inverting buck-boost converter

This study presents a pre-calculated duty cycle optimization method based on the genetic algorithm for a non-inverting buck-boost converter (NIBBC). In this method, the duty cycles are calculated via a discrete model estimation of NIBBC. Despite its high computational time requirements, this method can find solutions to problems that other methods cannot overcome due to their lack of linearity, continuity, or other features. This algorithm is developed using the TMS320F28335 digital signal processor, which is a 32-bit floating point processor operating at 150 MHz. The robustness and stability of this method at varying input voltages, loads, and parameters are then analyzed following the IEEE and IEC standards. The experimental results verify the simulation results and highlight the efficiency, power quality, wide output voltage range, and stability of the proposed method.

Sources of Nonlinear van't Hoff Temperature Dependence in High-Performance Liquid Chromatography.

In HPLC, the nonlinear behavior of the retention factor k′ with temperature (dependence of ln k′ on 1/T) can be attributed to the multiple interactions of a unique analyte in the separation process and/or to the existence in solution of multiple forms of the analyte (also leading to different free enthalpies of interaction). In this study, several examples of nonlinear retention–temperature dependence are evaluated for both reversed-phase (RP) and hydrophilic interaction chromatography (HILIC) separations. The potential explanation for nonlinear retention–temperature behavior is evaluated for each example, some caused by multiple interactions in the separation system of a unique analyte and others by multiple forms of the analyte. In cases where the analyte does not have more forms and the separation is based predominantly on one type of interaction (e.g., hydrophobic interaction in RP-HPLC), the dependence is linear, as expected. By studying the changes in the chemical structure of a compound as a function of pH it is possible to decide, in many cases, if a unique form or multiple forms of a compound are present in the solution. The use of this information allows us to determine when the lack of linearity (when present) is caused by multiple interactions in the separation system (for one form of the compound) and when more forms are causing the lack of linearity. The approximation with a quadratic form for the nonlinear dependence has been verified in most cases to be good, and only minor improvements were obtained when using higher polynomial dependencies.

An investigation of the component of response spectrum uncorrelated with input

Abstract For a linear system, by definition, the response spectrum is related to the input spectrum through a linear transformation. An investigation of the component of the response spectrum disobeying such a correlation gives way to a non-parametric algorithm which can help detect nonlinearities in the system being tested. The uncorrelated component thus obtained contains information pertinent to both structural nonlinearities and any lack of linearity resulting from the digital signal processing (DSP) techniques employed. The current paper discusses an approach that combines cyclic averaging with the aforementioned detection scheme to help segregate the uncorrelated response components based on leakage from those due to the dynamic characteristics of the system. This scheme is then shown to be successful on numerical and experimental data sets with representative examples for both linear and nonlinear systems.

Implementation of Transmigration Settlement Unit Transformation to Village Policy for Increasing Society Welfare in Indonesia

This research relies on the concept of process theory and policy implementation determinants from Hamdi (2014), where the theoretical concepts of policy implementation processes include dimensions of productivity, linearity, and efficiency, while the theoretical determinants of policy implementation include substance policy factors, behavior of implementing tasks, network interactions employment, target group participation, and resource factors. The research method used in this study is a qualitative research method with the characteristics of construction built on natural conditions, more descriptive, more emphasis on processes, inductive analysis, and more emphasis on the value or meaning contained in a data or event. In an effort to obtain accurate analysis results related to the process and the determinants of the implementation of the transmigration settlement unit transformation into Madapuhi Trans Village, the informants selected were all stakeholders at the local level, both local government and the community. This study found that the process of implementing the UPT transformation policy into Madapuhi Trans Village has not gone well, as indicated by low productivity, lack of linearity and lack of efficiency in policy implementation, as well as several factors that hinder successful implementation of policies such as Policy Substance, Implementing Task Behavior, Target Group Participation, and Resources. The supporting factors in implementing this policy are factors of network interaction. The results also showed that from the 5 determinants of policy implementation, the Target Group Participation factor was the most influential factor in the context of the implementation of the transformation of the transmigration settlement unit to the Madapuhi Trans Village. This study found that understanding harmony is also a determinant of policy implementation. The model produced by this research is the model of the Effectiveness of the Process of Implementing the Policy of Transforming the UPT into a village. Based on the results and findings of the study, it is suggested that a theory of the implementation of the transformation of the transmigration settlement unit into a village be developed, which includes the theory of the process of policy implementation and the determinant theory of policy implementation by Hamdi.

Self-Calibration Algorithm for a Pressure Sensor with a Real-Time Approach Based on an Artificial Neural Network.

This paper presents a novel approach to predicting self-calibration in a pressure sensor using a proposed Levenberg Marquardt Back Propagation Artificial Neural Network (LMBP-ANN) model. The self-calibration algorithm should be able to fix major problems in the pressure sensor such as hysteresis, variation in gain and lack of linearity with high accuracy. The traditional calibration process for this kind of sensor is a time-consuming task because it is usually done through manual and repetitive identification. Furthermore, a traditional computational method is inadequate for solving the problem since it is extremely difficult to resolve the mathematical formula among multiple confounding pressure variables. Accordingly, this paper describes a new self-calibration methodology for nonlinear pressure sensors based on an LMBP-ANN model. The proposed method was achieved using a collected dataset from pressure sensors in real time. The load cell will be used as a reference for measuring the applied force. The proposed method was validated by comparing the output pressure of the trained network with the experimental target pressure (reference). This paper also shows that the proposed model exhibited a remarkable performance than traditional methods with a max mean square error of 0.17325 and an R-value over 0.99 for the total response of training, testing and validation. To verify the proposed model’s capability to build a self-calibration algorithm, the model was tested using an untrained input data set. As a result, the proposed LMBP-ANN model for self-calibration purposes is able to successfully predict the desired pressure over time, even the uncertain behaviour of the pressure sensors due to its material creep. This means that the proposed model overcomes the problems of hysteresis, variation in gain and lack of linearity over time. In return, this can be used to enhance the durability of the grasping mechanism, leading to a more robust and secure grasp for paralyzed hands. Furthermore, the exposed analysis approach in this paper can be a useful methodology for the user to evaluate the performance of any measurement system in a real-time environment.

Ocular Signs Related to Overweight and Arterial Hypertension in Children: A Systematic Review.

Background:The ocular effects of obesity and hypertension need to be established and can be used as prognostic markers.Objective:To estimate the prevalence of ophthalmological alterations in children and adolescents who are overweight and/or have SAH.Methods:The database for this study included all observational studies (CS, cohort, case-control and “baseline” description of randomized clinical trials) with children and/or adolescents who were overweight, obese or had SAH and that measured ophthalmological alterations.Results:Comparative studies with healthy children demonstrated positive association between body adiposity with retinal venular dilation, and SAH with retinal arteriolar narrowing. Different retinal fundus cameras and computer-assisted programs to evaluate the retinal vessels, variations in the methods of analysis, adjustments, populations, were the main arguments against formal meta-analysis. The heterogeneity was too high (I2 >90%, in fixed or randomized effects), and the lack of linearity, normal distribution and homoscedasticity did not recommend meta-regression.Conclusion:Obesity and SAH show associations with ophthalmological alterations, especially with retinal vessel diameter. Lack of standardization does not allow a quantitative evaluation.

A Tale of Ambivalence: Salman Rushdie’s “Two Years, Eight Months and Twenty-Eight Nights”

Salman Rushdie’s memoirs, essays and novels contribute to the appreciation of the contradictions in his outlook on life. His experiences in his family enable Rushdie to make efforts for objective and tolerant judgement of British lifestyle and culture. However, his isolation from the society in Britain despite his struggle for adaptation to British cultural values cause contradictions in his cultural identity. While Rushdie expresses his allegiance to India and its culture in The Ground Beneath Her Feet (1999), he reflects his alienation from his homeland in this novel as well. Similarly, in his Imaginary Homelands (1981-1991) whereas Rushdie questions the injustice and inequality caused by imperialism in The New Empire within Britain (1982), he justifies the colonialist discourse in Kipling (1990). He elaborates on the contradictions in his outlook on life in terms of his cultural ambivalence in his fictions such as Midnight’s Children (1981) and Shame (1983). However, in his latest novel, Two Years, Eight Months and Twenty-Eight Nights (2015), Rushdie reflects his cultural identity conflict in terms of rationalism-mysticism dichotomy. With the use of allegory as well as the lack of linearity in time and space, Rushdie justifies his cultural ambivalence in relation to the dynamism of contemporary world. Thus, Rushdie’s latest novel invites reading for its representation of the oppositions in his approach to life.

Comparison of ABL1 and Gusb Reference Genes in the qRT-PCR Analysis of Halving Time and Early Molecular Response to TKI Therapy in Patients with Chronic Myeloid Leukemia

Objectives and background: Early molecular response (EMR) to tyrosine kinase inhibitors (TKI) therapy defined as BCR-ABL1 transcript level ≤ 10% at 3 months is a well-established predictive factor in CML patients. Recently, several study groups presented the concept of BCR-ABL1 decline velocity or "halving time" as a new predictive factor for optimal TKI treatment response. Different reference genes were used in the quantitative RT-PCR (qRT-PCR) analysis to calculate halving time and EMR rate, potentially influencing results of these analyses. The aim of the study was to compare ABL1 and beta-glucuronidase (GUSB) as reference genes used for calculation of halving time and EMR rate in chronic phase CML patients (pts) treated with imatinib 400 mg/d in the clinical settings.Methods: A total of 52 chronic phase CML pts with blood samples collected at baseline and at 3 months of imatinib therapy were investigated. Transcript levels of BCR-ABL1 were determined by qRT-PCR with the use of ABL1 and GUSB as control genes for each patient. Halving time for BCR-ABL1 transcripts was calculated using baseline transcript levels, transcript levels at 3 months of treatment, and number of days between these two points according to methodology reported elswhere1. Using receiver operating characteristic (ROC) analysis, the optimal halving time thresholds for achievement of EMR for each control gene were determined. Optimal thresholds along the ROC curves were calculated using the Youden index.Results: 40 of 52 (76.9%) and 44 of 52 (84.6%) pts achieved EMR with BCR-ABL1 transcripts levels calculated with GUSB and ABL1 as control genes, respectively (p=0.55). In 4 pts there was no BCR-ABL1 transcript reduction from baseline at 3 month using GUSB as a control gene resulting with negative halving times. The GUSB based halving times of these 4 patients were imputed to the longest positive halving time (8530 days) calculated for the patient with the smallest BCR-ABL1 decline. Transcript reduction occurred in all pts when ABL1 was used as a control gene. ROC curve analysis resulted in the optimal halving time thresholds for achievement of EMR of 39 days (area under the curve [AUC ] 0.96, ;95% CI 0.9-1.0, ) and 31 days (AUC 0.95; 95% CI 0.87-1.0, ) for GUSB and ABL1 control gene, respectively.Discussion and Conclusions: Lack of linearity in qRT-PCR analysis observed in blood samples collected in CML patients at diagnosis, with high amount of BCR-ABL1 and wild type ABL1 transcripts could affect the accuracy of early kinetics decline of BCR-ABL1 transcript calculations when ABL1 is used as a reference gene. The analysis with the use of GUSB as a control gene is not biased by this phenomenon. In this study, a non - statistically significant differences in the rate of EMR achieved at 3 months of imatinib therapy and halving time were observed. Analyses performed in our study with ABL1 and GUSB as reference genes suggest that both GUSB and ABL1 are able to identify relevant cut-offs for EMR achievement and could be used for halving time calculation.Reference:Branford S, Yeung DT, Parker WT, et al. Prognosis for patients with CML and >10% BCR-ABL1 after 3 months of imatinib depends on the rate of BCR-ABL1 decline. Blood 2014 Jul 24;124(4):511-8 DisclosuresZawada:Novartis: Speakers Bureau. Czekalska:Novartis: Speakers Bureau. Sacha:Pfizer: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Adamed: Consultancy, Honoraria.

Myocardial perfusion cardiovascular magnetic resonance: optimized dual sequence and reconstruction for quantification

BackgroundQuantification of myocardial blood flow requires knowledge of the amount of contrast agent in the myocardial tissue and the arterial input function (AIF) driving the delivery of this contrast agent. Accurate quantification is challenged by the lack of linearity between the measured signal and contrast agent concentration. This work characterizes sources of non-linearity and presents a systematic approach to accurate measurements of contrast agent concentration in both blood and myocardium.MethodsA dual sequence approach with separate pulse sequences for AIF and myocardial tissue allowed separate optimization of parameters for blood and myocardium. A systems approach to the overall design was taken to achieve linearity between signal and contrast agent concentration. Conversion of signal intensity values to contrast agent concentration was achieved through a combination of surface coil sensitivity correction, Bloch simulation based look-up table correction, and in the case of the AIF measurement, correction of T2* losses. Validation of signal correction was performed in phantoms, and values for peak AIF concentration and myocardial flow are provided for 29 normal subjects for rest and adenosine stress.ResultsFor phantoms, the measured fits were within 5% for both AIF and myocardium. In healthy volunteers the peak [Gd] was 3.5 ± 1.2 for stress and 4.4 ± 1.2 mmol/L for rest. The T2* in the left ventricle blood pool at peak AIF was approximately 10 ms. The peak-to-valley ratio was 5.6 for the raw signal intensities without correction, and was 8.3 for the look-up-table (LUT) corrected AIF which represents approximately 48% correction. Without T2* correction the myocardial blood flow estimates are overestimated by approximately 10%. The signal-to-noise ratio of the myocardial signal at peak enhancement (1.5 T) was 17.7 ± 6.6 at stress and the peak [Gd] was 0.49 ± 0.15 mmol/L. The estimated perfusion flow was 3.9 ± 0.38 and 1.03 ± 0.19 ml/min/g using the BTEX model and 3.4 ± 0.39 and 0.95 ± 0.16 using a Fermi model, for stress and rest, respectively.ConclusionsA dual sequence for myocardial perfusion cardiovascular magnetic resonance and AIF measurement has been optimized for quantification of myocardial blood flow. A validation in phantoms was performed to confirm that the signal conversion to gadolinium concentration was linear. The proposed sequence was integrated with a fully automatic in-line solution for pixel-wise mapping of myocardial blood flow and evaluated in adenosine stress and rest studies on N = 29 normal healthy subjects. Reliable perfusion mapping was demonstrated and produced estimates with low variability.

Vietnam's forest transition in retrospect: demonstrating weaknesses in business-as-usual scenarios for REDD.

One of the prerequisites of the REDD+ mechanism is to effectively predict business-as-usual (BAU) scenarios for change in forest cover. This would enable estimation of how much carbon emission a project could potentially prevent and thus how much carbon credit should be rewarded. However, different factors like forest degradation and the lack of linearity in forest cover transitions challenge the accuracy of such scenarios. Here we predict and validate such BAU scenarios retrospectively based on forest cover changes at village and district level in North Central Vietnam. With the government's efforts to increase the forest cover, land use policies led to gradual abandonment of shifting cultivation since the 1990s. We analyzed Landsat images from 1973, 1989, 1998, 2000, and 2011 and found that the policies in the areas studied did lead to increased forest cover after a long period of decline, but that this increase could mainly be attributed to an increase in open forest and shrub areas. We compared Landsat classifications with participatory maps of land cover/use in 1998 and 2012 that indicated more forest degradation than was captured by the Landsat analysis. The BAU scenarios were heavily dependent on which years were chosen for the reference period. This suggests that hypothetical REDD+ activities in the past, when based on the remote sensing data available at that time, would have been unable to correctly estimate changes in carbon stocks and thus produce relevant BAU scenarios.

Memories from the communist world

In this essay the renowned critic Nicolae Manolescu presents a memoir of his literary experiences since his schooldays until the post-socialist period in Romania. Noteworthy is the lack of linearity in the narrative, which questions several literary stereotypes.

Challenges in selectivity, specificity and quantitation range of ligand-binding assays: case studies using a microfluidics platform.

Method developers of plate-based ligand-binding assays (LBAs) often face challenges establishing selectivity, specificity and range of quantitation to meet the needs of a particular study. Case studies are presented to compare different ligand-binding immunoassay platforms (plate-based vs microfluidic system) in method development to support pharmacokinetic and pharmacodynamic studies. Studies highlight the challenges of plate-based LBAs to establish selectivity, specificity and range of quantitation as a result of nonspecific background signal, matrix interference, lack of linearity and drug interference. The fast assay kinetics of a microfluidic immunoassay system was shown to generally reduce nonspecific background and matrix effects, while increasing assay linear range and drug tolerance. The short incubation times with microfluidics can be beneficial for LBAs burdened by matrix effects and in these cases had superior assay performance compared with widely used immunoassay platforms in bioanalysis, for example, Meso Scale Discovery(®) and enzyme-linked immunosorbent assay.

Estudo morfométrico dos esporos fósseis e atuais da família anemiaceae do cretáceo inferior ao quaternário

O presente estudo foi baseado na morfometria de 112 morfoespécies de esporos fósseis relacionadas à Anemiaceae (Classe Polypodiopsida, Ordem Schizaeales) oriundas de diversos estratos de bacias brasileiras, abrangendo desde o Cretáceo Inferior até o Quaternário, e de esporos de 129 espécies viventes da família no mundo. O objetivo é averiguar a relação existente entre caracteres morfométricos, cronoestratigrafia e clima/paleoclima. Foram levantados os seguintes parâmetros: D1 (diâmetro maior), D2 (diâmetro menor), EM (espessura do muro) e DM (distância entre os muros). As medidas obtidas em micrômetro foram arquivadas na planilha Excel, visando à confecção de gráficos de regressão linear, os quais forneceram os seguintes resultados: (1) D1 e D2 se correlacionam com linearidade perfeita, independente da idade geológica e do clima, o que é esperado, já que os esporos de Anemiaceae se caracterizam pelo âmbito equidimensional; (2) na relação entre D1 e EM, os valores de D1 aumentam, grosso modo, com o aumento da espessura do muro, sem, contudo, apresentar uma linearidade perfeita. A falta da linearidade é notável nas espécies do Cretáceo Inferior, onde predominam muros finos. No Cretáceo Inferior, os muros mais espessos não passam de 4 µm, enquanto no Cretáceo Superior, foram observados muros de até 8 µm. Entre as espécies atuais, desprovidas de muros muito finos, é observada certa linearidade, independentemente do tipo de clima; (3) a relação EM x DM não apresenta nenhuma correlação nas espécies do Cretáceo ao Terciário, registrando uma ampla gama de valores de DM para cada valor de EM. Isto era esperado, já que a espessura do muro e a distância entre os muros são, a priori, parâmetros independentes. No Cretáceo, os valores de DM são geralmente pequenos, predominando valores menores que 2 µm. Já no Terciário, os valores de DM variam de 0,5 µm a 6 µm. As espécies viventes apresentam relação inversa entre EM e DM, principalmente entre as espécies do clima semiárido a semiúmido. Essa relação não existe entre as espécies fósseis, em função da existência de espécies com muros finos e densos (e.g., Cicatricosisporites microstriatus, C. minutaestriatus e C. avnimelechi) e de espécies com muros de espessura mediana com grande distância entre eles (e.g., Cicatricosisporites hughesii e C. purbeckensis).