Principal Function Research Articles

The effect of anisotropy on cross section spectra of uniaxial spherical particles small compared to the wavelength

We study the effect of anisotropy on the extinction, absorption and scattering spectra of optically uniaxial spherical particles, which are small compared to the wavelength of the incident light, in the infrared spectral region. To do so we compare simulated Finite-Difference Time-Domain (FDTD) spectra of the uniaxial sphere to spectra of a corresponding isotropic materials calculated with Mie-theory, which are given the principal dielectric functions of the ordinary and extraordinary axes, respectively. Several effects of anisotropy can be observed, caused by the incident plane wave being bent around the sphere and penetrating into the sphere.

Aldosterone Regulates Pendrin and Epithelial Sodium Channel Activity through Intercalated Cell Mineralocorticoid Receptor-Dependent and -Independent Mechanisms over a Wide Range in Serum Potassium.

Aldosterone activates the intercalated cell mineralocorticoid receptor, which is enhanced with hypokalemia. Whether this receptor directly regulates the intercalated cell chloride/bicarbonate exchanger pendrin is unclear, as are potassium's role in this response and the receptor's effect on intercalated and principal cell function in the cortical collecting duct (CCD). We measured CCD chloride absorption, transepithelial voltage, epithelial sodium channel activity, and pendrin abundance and subcellular distribution in wild-type and intercalated cell-specific mineralocorticoid receptor knockout mice. To determine if the receptor directly regulates pendrin, as well as the effect of serum aldosterone and potassium on this response, we measured pendrin label intensity and subcellular distribution in wild-type mice, knockout mice, and receptor-positive and receptor-negative intercalated cells from the same knockout mice. Ablation of the intercalated cell mineralocorticoid receptor in CCDs from aldosterone-treated mice reduced chloride absorption and epithelial sodium channel activity, despite principal cell mineralocorticoid receptor expression in the knockout mice. With high circulating aldosterone, intercalated cell mineralocorticoid receptor gene ablation directly reduced pendrin's relative abundance in the apical membrane region and pendrin abundance per cell whether serum potassium was high or low. Intercalated cell mineralocorticoid receptor ablation blunted, but did not eliminate, aldosterone's effect on pendrin total and apical abundance and subcellular distribution. With high circulating aldosterone, intercalated cell mineralocorticoid receptor ablation reduces chloride absorption in the CCD and indirectly reduces principal cell epithelial sodium channel abundance and function. This receptor directly regulates pendrin's total abundance and its relative abundance in the apical membrane region over a wide range in serum potassium concentration. Aldosterone regulates pendrin through mechanisms both dependent and independent of the IC MR receptor.

Multiple additive models

The models constituting a multiple model will correspond to d treatments of a base design. When we have individual additive models with independent, with independent components, with the th order cumulants, the multiple model will be additive. Using a classic result on cumulant generation function we show how to obtain least square estimators for cumulants and generalized least squares estimators for vectors in the individual models. Next we carry out ANOVA-like analysis for the action of the factors in the base design. This is possible since the estimators of have, approximately, the same covariance matrix. The eigenvectors of that matrix will give the principal estimable functions for the individual models. The ANOVA-like analysis will consider homolog components on principal estimable functions. To apply our results we assume the factors in the base design to have fixed effects. Moreover if and has covariance matrix our treatment generalizes that previously given for multiple regression designs. In them we have a linear regression for each treatment of a base design. We then study the action of the factors on that design on the vectors An example of application of the proposed methodology is given.

Septin architecture and function in budding yeast.

The septins constitute a conserved family of guanosine phosphate-binding and filament-forming proteins widespread across eukaryotic species. Septins appear to have two principal functions. One is to form a cortical diffusion barrier, like the septin collar at the bud neck of Saccharomyces cerevisiae, which prevents movement of membrane-associated proteins between the mother and daughter cells. The second is to serve as a polymeric scaffold for recruiting the proteins required for critical cellular processes to particular subcellular areas. In the last decade, structural information about the different levels of septin organization has appeared, but crucial structural determinants and factors responsible for septin assembly remain largely unknown. This review highlights recent findings on the architecture and function of septins and their remodeling with an emphasis on mitotically dividing budding yeasts.

Frequency Truncated Discrete-Time System Norm

Computation of the frequency truncated norm of a discrete-time linear time-invariant system is required in multi-rate digital signal processing and model reduction applications. For a system represented using state-space equations, the frequency truncated norm itself is a particular case of an integral of the transfer function of a discrete-time linear time-invariant descriptor system over a limited frequency band. This letter provides closed-form expressions for this integral and the frequency truncated norm for direct computation in terms of the principal logarithm and matrix exponential function.

A stepwise approach to resolving small ionic currents in vascular tissue.

Arterial membrane potential (Vm) is set by an active interplay among ion channels whose principal function is to set contractility through the gating of voltage-operated Ca2+ channels. To garner an understanding of this electrical parameter, the activity of each channel must be established under near-physiological conditions, a significant challenge given their small magnitude. The inward rectifying K+ (KIR) channel is illustrative of the problem, as its outward "physiological" component is almost undetectable. This study describes a stepwise approach to dissect small ionic currents at physiological Vm using endothelial and smooth muscle cells freshly isolated from rat cerebral arteries. We highlight three critical steps, beginning with the voltage clamping of vascular cells bathed in physiological solutions while maintaining a giga-ohm seal. KIR channels are then inhibited (micromolar Ba2+) so that a difference current can be created, once Ba2+ traces are corrected for the changing seal resistance and subtle instrument drift, pulling the reversal potential rightward. The latter is a new procedure and entails the alignment of whole cell current traces at a voltage where KIR is silent and other channels exhibit limited activity. We subsequently introduced corrected and uncorrected currents into computer models of the arterial wall to show how these subtle adjustments markedly impact the importance of KIR in Vm and arterial tone regulation. We argue that this refined approach can be used on an array of vascular ion channels to build a complete picture of how they dynamically interact to set arterial tone in key organs like the brain.NEW & NOTEWORTHY This work describes a stepwise approach to resolve small ionic currents involved in controlling Vm in resistance arteries. Using this new methodology, we particularly resolved the outward component of the KIR current in native vascular cells, voltage clamped in near-physiological conditions. This novel approach can be applied to any other vascular currents and used to better interpret how vascular ion channels cooperate to control arterial tone.

Functional domains of the FgfrL1 receptor

FgfrL1 is a novel growth factor receptor that is primarily expressed in musculoskeletal tissues and the kidney. FgfrL1-deficient mice have a malformed diaphragm and no kidneys. Such animals die immediately after birth because they are not able to inflate their lungs.The FgfrL1 molecule is composed of three extracellular Ig domains, a transmembrane helix and a short intracellular domain. To investigate the contribution of each of these domains to the function of the novel receptor, we generated mice with deletions of the individual domains. Mice lacking the intracellular domain are viable and phenotypically normal. Mice lacking the first (N-terminal) Ig domain are also viable and normal, but have a reduced life span. Mice lacking the Ig2 or the Ig3 domain are born alive, but die within 24 ​h after birth. Ig2-deficient animals exhibit substantially smaller kidneys than wild-type littermates and contain a lower number of glomeruli. Ig3-deficient mice completely lack metanephric kidneys. Interestingly, both the Ig2 and the Ig3-deficient animals show only minor alterations in the diaphragm, which still enables them to inflate their lungs after birth.Our results demonstrate that the principal function of the FgfrL1 receptor is to control the growth of the metanephric kidneys by regulating nephrogenesis. It appears that this function is primarily accomplished by the Ig3 domain with some contribution of the Ig2 domain. It is conceivable that the two domains interact with an Fgf ligand and another molecule from the surface of neighboring cells to induce condensation of the metanephric mesenchyme to renal epithelia and glomeruli.

Evaluation of a coated blade spray-tandem mass spectrometry assay as a new tool for the determination of immunosuppressive drugs in whole blood.

Immunosuppressive drugs (ISDs) are primarily administered following solid organ transplant or for treatment of a variety of autoimmune conditions. Their principal function is to suppress the activity of the immune system; however, the levels must be carefully monitored due to adverse effects of over- or underadministration. A technology for rapid quantitative screening, named coated blade spray (CBS), was directly coupled to a triple quadrupole mass spectrometer (MS/MS) to measure the concentration of ISDs (i.e., cyclosporine A, tacrolimus, everolimus, sirolimus) in whole blood samples. We evaluated the stability of replicate measurements over a 10-day period (precision), assessed linearity and limit of quantification, and performed a method comparison against a validated clinical immunoassay (Abbott ARCHITECT). Total interday variation of less than 5% for all target compounds at three different concentrations was achieved. The sensitivity of the method was determined as 0.25, 1, 1, and 2.5ng/mL for everolimus, sirolimus, tacrolimus, and cyclosporine A, respectively. The concentrations of three immunosuppressive drugs in 284 patient samples (i.e., ~ 95 samples of cyclosporine A, tacrolimus, or sirolimus) obtained using the CBS-MS/MS methodology were compared with concentrations previously quantified on an Abbott ARCHITECT immunoassay system. Our analysis demonstrated significant statistical similarities between both methods. The results demonstrate that CBS-MS/MS is a suitable alternative to conventional methodologies for monitoring of ISDs from whole blood in a clinical setting. Graphical abstract.

A novel [formula omitted] bus pair method of biomass DGs placement in distribution networks to maintain the voltage of remotely located buses

This paper proposes a new DG placement and sizing technique by introducing a novel Q−PQV bus pair in distribution networks (DNRs) with seasonal variation of load demand. The principle aim of this paper is to boost and maintain the voltage of remotely located buses to predefined optimal level for seasonal load demand by integrating biomass DGs in DNRs. The selection of locations and sizes of DGs is determined by novel bus pair, which is different from conventional buses present in power system studies. For PQV bus along with active and reactive power, the voltage magnitude also is known, whereas, for Q bus, only reactive power is known. The power injection of Q bus with the load connected determines DG sizes. The inclusion of this new bus pair modifies the load flow technique, which is also given in the paper. The proposed methodology is applied on 33 bus DNR, while active power loss is taken as principal objective function. Both upf and lpf DGs are considered in this paper, and the results are compared with existing methods available in literature. The cost-benefit analysis shows the profit gained from it.

Application of mathematical models and microfluidics in the analysis of saliva mixing with antiseptic solutions

Background/Aim: Human saliva offers many advantages over blood-based biochemical assays, therefore, becomes the biological fluid of interest. Once antiseptic solutions react with saliva, both fluids undergo significant changes of their biophysical properties, consequently, those changes have an impact on their principal function. Material and Methods: In this study, saliva was collected and mixed with 0,1% chlorhexidine digluconate solution, fluoride mouthwash, zinc-hydroxyapatite solution and CPP-ACP paste. Microfluidic PVC/Green tape chips within the experimental setup were used to simulate solution mixing. The chip had 2 inlets and 1 outlet, and channel was designed in Y shape without any obstacles. The inlet channels were set at a 60° angle. The channel width was 600 µm and the diameter of inlets and outlet was 2 mm. For better visualization, blue food coloring was added to the saliva. The procedure was recorded with digital USB microscope camera and afterwards the percentage of mixing was obtained by MATLAB programming language. Results: Obtained results show incomplete mixing of all the solutions with saliva. The value of mixed liquid, when mixing 0,1% chlorhexidine digluconate solution with saliva was 51,11%. In case of medium concentration fluoride mouthwash, result was 84,37%. Zinc hydroxyapatite solution obtained result of 85,24%, and the fourth tested solution, CPP-ACP paste, 83,89%. Conclusions: Analyzed mouthwashes exhibit specific, non uniform behavior during mixing with saliva. Microfluidic setups could be efficiently used in simulating real clinical conditions in laboratory settings. Image processing mathematical models are applicable, accurate and useful in determination of the interaction of saliva with commonly used antiseptic solutions.

Reactualization of the Function and Role of Principals in Senior High Schools (SMA) in Luwu Regency, Indonesia

Reactualization of the Function and Role of Principals in Senior High Schools (SMA) in Luwu Regency, Indonesia

Point Cloud Reduction and Denoising Based on Optimized Downsampling and Bilateral Filtering

For the issue of using the center of gravity during down-sampling, some points of their feature will be lost. We propose a new method, FWD(Farthest point Weighted mean Down-sampling), this method uses down-sampling to find the center of gravity, it is added to the furthest point sampling and performed ten iterations. The obtained 11-point distance is weighted average to find the feature point. Influences of environmental noise and self-noises on the subsequent processing of point cloud are considered. A PWB (Principal component analysis Wavelet function Bilateral Filtering) method is proposed. The normal vector of points is calculated by PCA. The distance between two points in the optimal neighborhood is obtained by the particle swarm optimization(PSO) method. This method performs wavelet smoothing and utilizes the Gaussian function to retain the edge eigenvalues. FWD simplified 90840 points in 48 seconds in the case of retaining the complete feature points. Compared with other latest methods, better results have been obtained. PWB reached de-noising precision of 0.9696 within 72.31s. Accuracy of de-noising is superior to the latest method. The loss of feature points is completed by FWD, the removal of noise is by PWB. Images of de-noising precision prove the priority of the method. The verification shows that the feature points are retained and the noise is eliminated.

Discrete‐time dynamic principal–agent models: Contraction mapping theorem and computational treatment

We consider discrete‐time dynamic principal–agent problems with continuous choice sets and potentially multiple agents. We prove the existence of a unique solution for the principal's value function only assuming continuity of the functions and compactness of the choice sets. We do this by a contraction mapping theorem and so also obtain a convergence result for the value function iteration. To numerically compute a solution for the problem, we have to solve a collection of static principal–agent problems at each iteration. As a result, in the discrete‐time setting solving the static problem is the difficult step. If the agent's expected utility is a rational function of his action, then we can transform the bi‐level optimization problem into a standard nonlinear program. The final results of our solution method are numerical approximations of the policy and value functions for the dynamic principal–agent model. We illustrate our solution method by solving variations of two prominent social planning models from the economics literature.

Approximate Triple Modular Redundancy: A Survey

In recent years, approximate computing (AC) has attracted attention owing to its tradeoff between the exactness of computations and performance gains. AC has also been probed for the technique of Triple modular redundancy (TMR). TMR is a well-known fault masking methodology, with associated overheads, widely used in systems of different nature and at different levels. E.g.: layout-level, gate-level, HW-module level, software. At hardware level, through exploitation of AC the 200% area overhead problem due to triplication of the original modules in TMR can be reduced. By approximating the modules of TMR while ensuring that at least two of the approximate modules do not differ from the original module for every input vector, the facilitation of fault masking can lead to overhead reduction. Hence, approximate TMR (ATMR) aims to achieve cost-effective reliability. Nevertheless, due to the extensive search space, computational complexity, and principal fault masking function of ATMR, designing an ATMR is a challenging task. An ATMR technique must be scalable so that it can be easily adopted by circuits having large number of inputs and the extraction of ATMR modules remains computationally inexpensive. Compared with TMR, due to the inclusion of approximations, ATMR is more vulnerable to errors, and hence, the design technique must ensure awareness of input-criticality. To the best of the authors' knowledge, none of the existing survey articles on AC has reported on ATMR. Therefore, in this work, ATMR design techniques are thoroughly surveyed and qualitatively compared. Moreover, design considerations and challenges for designing ATMR are discussed.

Measurement of mitochondrial respiration in permeabilized fish gills.

ABSTRACTPhysiological investigations of fish gills have traditionally centred on the two principal functions of the gills: gas exchange and ion regulation. Mitochondrion-rich cells (MRCs) are primarily found within the gill filaments of fish, and are thought to proliferate in order to increase the ionoregulatory capacity of the gill in response to environmentally induced osmotic challenges. However, surprisingly little attention has been paid to the metabolic function of mitochondria within fish gills. Here, we describe and validate a simple protocol for the permeabilization of fish gills and subsequent measurement of mitochondrial respiration rates in vitro. Our protocol requires only small tissue samples (8 mg), exploits the natural structure of fish gills, does not require mechanical separation of the gill tissue (so is relatively quick to perform), and yields accurate and highly reproducible measurements of respiration rates. It offers great potential for the study of mitochondrial function in gills over a wide range of fish sizes and species.

Von Willebrand Disease: The diagnosis and management of this bleeding disorder

von Willebrand disease (vWD) is one of the most common bleeding disorders, first described by Erik von Willebrand in the Aland Islands. It occurs as a result of decreased or abnormal von Willebrand factor (vWF), a factor that is needed in the process of blood coagulation; acting like a “glue” helping platelets to stick together and form the blood clot. The principal function of vWF is binding with other clotting factors (especially Factor VIII) that are also necessary in the clotting process. There are two main forms of this disease: the inherited and the acquired forms; each one's pathophysiology depends on the qualitative or the quantitative defects in vWF. The diagnosis of vWD depends on several factors: measurement of vWD antigen, vWF activity assay, the activity of Factor VIII, and some other additional tests. The management of this disease includes replacement therapy, nonreplacement therapy, and some other kinds of managements that include the use of fibrinolytics and topical agents.

НОВАЯ МОДЕЛЬ ОБРАЗОВАТЕЛЬНОЙ ДЕЯТЕЛЬНОСТИ МУЗЕЯ В УСЛОВИЯХ XXI ВЕКА

The article outlines the need to create a new didactic model of museum education activities, which will form the basis for its interaction with school. This need arises from visitors’ personality alternations, which cause education system changes as well as changes in the principal functions of the museum. The new model of school-museum interaction is based on a sociocultural approach, which is considered to be a methodological basis for education activities. . The new form of interaction involves the introduction of new didactic tools into museum education activities.

Principal single-index varying-coefficient models for dimension reduction in quantile regression

ABSTRACTWe propose a principal single-index varying-coefficient model focusing on conditional quantiles. In this general and flexible class of models, dimension reduction is achieved in three aspects: first, standard varying-coefficient models can partially avoid curse of dimensionality of large dimensional nonparametric regression; second, a one-dimensional adaptive index is constructed from multiple index variables; finally, the number of independent functions is further reduced by using principal functions. We derive the convergence rate of the estimates and asymptotic normality of the index parameter and the coefficient functions. Penalization can be added straightforwardly to obtain joint variable selection and dimension reduction. Simulations are used to demonstrate the performances and an empirical application is presented.

Seasonal Wind Energy Characterization in the Gulf of Mexico

In line with Mexico’s interest in determining its wind resources, in this paper, 141 locations along the states of the Gulf of Mexico have been analyzed by calculating the main wind characteristics, such as the Weibull shape (c) and scale (k) parameters, and wind power density (WPD), by using re-analysis MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications version 2) data with hourly records from 1980–2017 at a 50-m height. The analysis has been carried out using the R free software, whose its principal function is for statistical computing and graphics, to characterize the wind speed and determine its annual and seasonal (spring, summer, autumn, and winter) behavior for each state. As a result, the analysis determined two different wind seasons along the Gulf of Mexico;, it was found that in the states of Tamaulipas, Veracruz, and Tabasco wind season took place during autumn, winter, and spring, while for the states of Campeche and Yucatan, the only two states that shared its coast with the Caribbean Sea and the Gulf of Mexico, the wind season occurred only in winter and spring. In addition, it was found that by considering a seasonal analysis, more accurate information on wind characteristics could be generated; thus, by applying the Weibull distribution function, optimal zones for determining wind as a resource of energy can be established. Furthermore, a k-means algorithm was applied to the wind data, obtaining three clusters that can be seen by month; these results and using the Weibull parameter c allow for selecting the optimum wind turbine based on its power coefficient or efficiency.

ITRAQ-Based Quantitative Proteomic Analysis of Digestive Juice across the First 48 Hours of the Fifth Instar in Silkworm Larvae.

The silkworm is an oligophagous insect for which mulberry leaves are the sole diet. The nutrients needed for vital activities of the egg, pupal, and adult stages, and the proteins formed in the cocoon, are all derived from the larval stages. The silkworm feeds and grows quickly during the larval stages. In particular, the amount of leaf ingested and digested quickly increases from the ecdysis to the gluttonous stage in the fifth instar period. In this study, we used the iTRAQ proteomic technique to identify and analyze silkworm larval digestive juice proteins during this period. A total of 227 proteins were successfully identified. These were primarily serine protease activity, esterase activity, binding, and serine protease inhibitors, which were mainly involved in the digestion and overcoming the detrimental effects of mulberry leaves. Moreover, 30 genes of the identified proteins were expressed specifically in the midgut. Temporal proteomic analysis of digestive juice revealed developmental dynamic features related to molecular mechanisms of the principal functions of digesting, resisting pathogens, and overruling the inhibitory effects of mulberry leaves protease inhibitors (PIs) with a dynamic strategy, although overruling the inhibitory effects has not yet been confirmed by previous study. These findings will help address the potential functions of digestive juice in silkworm larvae.