function models
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2022 ◽  
pp. 239-260
Author(s):  
Russell G. Almond

Author(s):  
M. Aurangzeib ◽  
S. Hussain ◽  
A. Rehim ◽  
M. A. Bashir ◽  
H. M. A. Raza

Understanding the dynamics of potassium (K) and its availability is fundamental in its efficient use as an important nutrient. The objectives of present study were to compare standard K extraction methods for extractable K and kinetics of K adsorption on five different textured soils. The soils were analyzed for physico-chemical properties, extractable K contents and kinetics of K adsorption. The soils had variable contents of soluble (8-52mg kg-1), exchangeable (13-215mg kg-1), fixed (488-1836mg kg-1), structural (2936-26362mg kg-1) and total K (3438-28517mg kg-1). Except soluble K, the amount of K in different forms was significantly (P?0.05) correlated with clay contents, electrical conductivity (EC), cation exchange capacity (CEC) and calcium carbonate in soils. Different methods variated the extracted K in different textured soils. Mehlich-III, ammonium acetate, AB-DTPA, and calcium chloride extracted K was maximum in sandy clay loam (298mg kg-1, 267mg kg?1, 226mg kg-1, and 113mg kg-1) and lowest was in loamy sand (33mg kg-1, 24mg  kg-1, 30mg kg-1, and 24mg   kg-1) respectively. Elovich and power function models best explained the K kinetics adsorption, as rate of adsorption constants were negatively correlated with sand contents in the soil type. Pearson correlation showed that the extractability of K by different methods and kinetics of K adsorption were dependent on soil texture EC, CEC and calcium carbonate contents. Hence, soil physico-chemical properties should be considered in recommending rate of K fertilization along with crop K demand and soil extractable K.


Author(s):  
Eugene Matthew P. Almazan ◽  
Joseph F. Ryan ◽  
Labib Rouhana

Detection of chemical stimuli is crucial for living systems and also contributes to quality of life in humans. Since loss of olfaction becomes more prevalent with aging, longer life expectancies have fueled interest in understanding the molecular mechanisms behind the development and maintenance of chemical sensing. Planarian flatworms possess an unsurpassed ability for stem cell-driven regeneration that allows them to restore any damaged or removed part of their bodies. This includes anteriorly-positioned lateral flaps known as auricles, which have long been thought to play a central role in chemotaxis. The contribution of auricles to the detection of positive chemical stimuli was tested in this study using Girardia dorotocephala, a North American planarian species known for its morphologically prominent auricles. Behavioral experiments staged under laboratory conditions revealed that removal of auricles by amputation leads to a significant decrease in the ability of planarians to find food. However, full chemotactic capacity is observed as early as 2 days post-amputation, which is days prior from restoration of auricle morphology, but correlative with accumulation of ciliated cells in the position of auricle regeneration. Planarians subjected to x-ray irradiation prior to auricle amputation were unable to restore auricle morphology, but were still able to restore chemotactic capacity. These results indicate that although regeneration of auricle morphology requires stem cells, some restoration of chemotactic ability can still be achieved in the absence of normal auricle morphology, corroborating with the initial observation that chemotactic success is reestablished 2-days post-amputation in our assays. Transcriptome profiles of excised auricles were obtained to facilitate molecular characterization of these structures, as well as the identification of genes that contribute to chemotaxis and auricle development. A significant overlap was found between genes with preferential expression in auricles of G. dorotocephala and genes with reduced expression upon SoxB1 knockdown in Schmidtea mediterranea, suggesting that SoxB1 has a conserved role in regulating auricle development and function. Models that distinguish between possible contributions to chemotactic behavior obtained from cellular composition, as compared to anatomical morphology of the auricles, are discussed.


Author(s):  
Noel Cressie ◽  
Matthew Sainsbury-Dale ◽  
Andrew Zammit-Mangion

Spatial statistics is concerned with the analysis of data that have spatial locations associated with them, and those locations are used to model statistical dependence between the data. The spatial data are treated as a single realization from a probability model that encodes the dependence through both fixed effects and random effects, where randomness is manifest in the underlying spatial process and in the noisy, incomplete measurement process. The focus of this review article is on the use of basis functions to provide an extremely flexible and computationally efficient way to model spatial processes that are possibly highly nonstationary. Several examples of basis-function models are provided to illustrate how they are used in Gaussian, non-Gaussian, multivariate, and spatio-temporal settings, with applications in geophysics. Our aim is to emphasize the versatility of these spatial-statistical models and to demonstrate that they are now center-stage in a number of application domains. The review concludes with a discussion and illustration of software currently available to fit spatial-basis-function models and implement spatial-statistical prediction. Expected final online publication date for the Annual Review of Statistics and Its Application, Volume 9 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Author(s):  
Francesca Baroni ◽  
Marco Tramontano ◽  
Nicola Barsotti ◽  
Marco Chiera ◽  
Diego Lanaro ◽  
...  

Abstract Objectives The construct of the osteopathic structure-function models is reported as a cornerstone of clinical reasoning and treatment processes. Nevertheless, there are no shared procedures described for their use in clinical practice. The present narrative review aims to analyze a more comprehensive perspective on the phenomenon. Methods A structured narrative review was conducted. A database search was conducted using Pubmed, ScienceDirect, and Google Scholar. Peer-reviewed papers without specifying limits on dates and design were included. Results Twenty-five findings were reported and grouped into two main themes: 1) Debate on models and theoretical frameworks for osteopathic care; 2) Clinical reasoning and decision-making process in the osteopathic field. Conclusions An integrated osteopathic care approach based on the structure/function models represents a starting point to establish a shared osteopathic diagnostic and clinical reasoning and an evidence-informed practice promoting health in an interdisciplinary person-centered care process. The present review highlights the limited amount of literature on using osteopathic conceptual models in decision-making and treatment strategies. A research plan is required to develop a common framework for an evidence-based osteopathic practice that promotes well-being in an interdisciplinary person-centered care process.


2021 ◽  
Author(s):  
Yann Guillouet ◽  
Oliver Keszocze ◽  
Frank Sill Torres

2021 ◽  
Vol 6 (10) ◽  
pp. 137
Author(s):  
Francesco Cavalieri ◽  
António A. Correia ◽  
Rui Pinho

Soil-structure interaction (SSI) effects are typically neglected for relatively lightweight buildings that are less than two-three storeys high with a limited footprint area and resting on shallow foundations (i.e., not featuring a basement). However, when the above conditions are not satisfied, and in particular when large basements are present, important kinematic SSI may develop, causing the foundation-level motion to deviate from the free-field one due to embedment effects. In the literature, transfer function models that estimate the filtering effect induced by rigid massless embedded foundations are available to “transform” foundation-level recordings into free-field ones, and vice-versa. This work describes therefore a numerical study aimed at assessing potential limits of the applicability of such transfer functions through the employment of a 3D nonlinear soil-block model representing a layered soil, recently developed and validated by the authors, and featuring on top a large heavy building with basement. A number of finite element site response analyses were carried out for different seismic input signals, soil profiles and embedment depths of the building’s basement. The numerically obtained transfer functions were compared with the curves derived using two analytical models. It was observed that the latter are able to reliably predict the embedment effects in “idealised” soil/input conditions under which they have been developed. However, in real conditions, namely when a non-homogeneous profile with nonlinear behaviour under a given seismic excitation is considered, especially in presence of a basement that is more than one storey high, they may fail in capturing some features, such as the frequency-dependent amplification of the motion at the basement level of a building with respect to the free-field one.


2021 ◽  
Vol 22 (18) ◽  
pp. 10001
Author(s):  
Curtis R. French

Axenfeld–Rieger syndrome (ARS) encompasses a group of developmental disorders that affect the anterior segment of the eye, as well as systemic developmental defects in some patients. Malformation of the ocular anterior segment often leads to secondary glaucoma, while some patients also present with cardiovascular malformations, craniofacial and dental abnormalities and additional periumbilical skin. Genes that encode two transcription factors, FOXC1 and PITX2, account for almost half of known cases, while the genetic lesions in the remaining cases remain unresolved. Given the genetic similarity between zebrafish and humans, as well as robust antisense inhibition and gene editing technologies available for use in these animals, loss of function zebrafish models for ARS have been created and shed light on the mechanism(s) whereby mutations in these two transcription factors cause such a wide array of developmental phenotypes. This review summarizes the published phenotypes in zebrafish foxc1 and pitx2 loss of function models and discusses possible mechanisms that may be used to target pharmaceutical development and therapeutic interventions.


2021 ◽  
Author(s):  
Zihao Deng ◽  
Tariq Butt ◽  
Benedicta D. Arhatari ◽  
Charbel Darido ◽  
Alana Auden ◽  
...  

Abstract The gene encoding the transcription factor, Grainyhead-like 3 (Grhl3), plays critical roles in mammalian development and homeostasis, and these have been uncovered through analysis of loss-of-function models. Grhl3-null embryos exhibit a range of gross phenotypes including a shortened longitudinal axis, thoraco-lumbo-sacral spina bifida and soft-tissue syndactyly. Additional studies reveal that these embryos also exhibit a proliferation/differentiation imbalance in the epidermis. This manifests as a failure in skin barrier formation resulting in peri-natal lethality, and defective wound repair. Conditional inactivation of Grhl3 in the squamous epithelium of adult skin, head and neck tissues, and oesophagus reproduces this proliferation/differentiation imbalance and leads to squamous cell carcinomas. These observations establish GRHL3 as a critical tumour suppressor. Despite these extensive analyses of Grhl3 loss-of-function models, the consequences of gain-of-function of this gene have been difficult to achieve. We have redressed this issue through the generation of a novel mouse model that expresses Grhl3 from a transgene integrated in the Rosa26 locus on an endogenous Grhl3-null background. Expression of the transgene rescues both the neurulation and skin barrier defects of the knockout mice, allowing survival into adulthood. Despite this, the mice are not normal, exhibiting a range of phenotypes attributable to dysregulated Grhl3 expression. In mice homozygous for the transgene, we observe a severe Shaker-Waltzer phenotype associated with hearing impairment. Micro-CT scanning of the cochleae and the vestibular apparatus revealed profound structural alterations underlying these phenotypes. In addition, these mice exhibit other developmental anomalies including hair loss, digit defects and epidermal dysmorphogenesis. These findings indicate that diverse developmental processes display low tolerance to dysregulation of Grhl3.


2021 ◽  
Author(s):  
Amaninder Singh Gil ◽  
Chiradeep Sen

Abstract This paper presents the development of logic rules for evaluating the fitness of function models synthesized by an evolutionary algorithm. A set of 65 rules for twelve different function verbs are developed. The rules are abstractions of the definitions of the verbs in their original vocabularies and are stated as constraints on the quantity, type, and topology of flows connected to the functions. The rules serve as an objective and unambiguous basis of evaluating the fitness of function models developed by a genetic algorithm. The said algorithm and the rules are implemented in software code, which is used to both demonstrate and validate the efficacy of the rule-based approach of converging function model synthesis using GAs.


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