scholarly journals Perturbation analysis of a multi-morphogen Turing reaction-diffusion stripe patterning system reveals key regulatory interactions

Development ◽  
2020 ◽  
Vol 147 (20) ◽  
pp. dev190553
Author(s):  
Andrew D. Economou ◽  
Nicholas A. M. Monk ◽  
Jeremy B. A. Green
Keyword(s):  
Perturbation Analysis ◽  
Reaction Diffusion ◽  
Regulatory Interactions ◽  
The People ◽  
Molecular Events ◽  
Experimental Constraint ◽  
Fgf Signalling ◽  
Analytical Approaches ◽  
Minimal Networks

ABSTRACTPeriodic patterning is widespread in development and can be modelled by reaction-diffusion (RD) processes. However, minimal two-component RD descriptions are vastly simpler than the multi-molecular events that actually occur and are often hard to relate to real interactions measured experimentally. Addressing these issues, we investigated the periodic striped patterning of the rugae (transverse ridges) in the mammalian oral palate, focusing on multiple previously implicated pathways: FGF, Hh, Wnt and BMP. For each, we experimentally identified spatial patterns of activity and distinct responses of the system to inhibition. Through numerical and analytical approaches, we were able to constrain substantially the number of network structures consistent with the data. Determination of the dynamics of pattern appearance further revealed its initiation by ‘activators’ FGF and Wnt, and ‘inhibitor’ Hh, whereas BMP and mesenchyme-specific-FGF signalling were incorporated once stripes were formed. This further limited the number of possible networks. Experimental constraint thus limited the number of possible minimal networks to 154, just 0.004% of the number of possible diffusion-driven instability networks. Together, these studies articulate the principles of multi-morphogen RD patterning and demonstrate the utility of perturbation analysis for constraining RD systems.This article has an associated ‘The people behind the papers’ interview.

scholarly journals The people behind the papers – Andrew Economou and Jeremy Green

Development ◽  
2020 ◽  
Vol 147 (20) ◽  
pp. dev197293
Keyword(s):  
Developmental Biology ◽  
Perturbation Analysis ◽  
Reaction Diffusion ◽  
Biological Complexity ◽  
Periodic Patterns ◽  
Alan Turing ◽  
King's College ◽  
The People

ABSTRACTInteracting morphogens produce periodic patterns in developing tissues. Such patterning can be modelled as reaction-diffusion (RD) processes (as originally formulated by Alan Turing), and although these models have been developed and refined over the years, they often tend to oversimplify biological complexity by restricting the number of interacting morphogens. A new paper in Development reports how perturbation analysis can guide multi-morphogen modelling of the striped patterning the roof of the mouse mouth. To hear more about the story, we caught up with first author Andrew Economou and his former supervisor Jeremy Green, Professor of Developmental Biology at King's College, London.

scholarly journals Perturbation analysis of a multi-morphogen Turing Reaction-Diffusion stripe patterning system reveals key regulatory interactions

2019 ◽  
Author(s):  
Andrew D. Economou ◽  
Nicholas A.M. Monk ◽  
Jeremy B.A. Green
Keyword(s):  
Network Topology ◽  
Perturbation Analysis ◽  
Reaction Diffusion ◽  
Signalling Pathways ◽  
Core Network ◽  
Pathway Network ◽  
Regulatory Interactions ◽  
Two Component ◽  
Network Topologies ◽  
Phase Relationships

AbstractPeriodic patterning is extremely widespread in developmental biology and is broadly modelled by Reaction-Diffusion (RD) processes. However, the minimal two-component RD system is vastly simpler than the multimolecular events that current biology is now able to describe. Moreover, RD models are typically underconstrained such that it is often hard to meaningfully relate the model architecture to real interactions measured experimentally. To address both these issues, we investigated the periodic striped patterning of the rugae (transverse ridges) in the roof of the mammalian palate. We experimentally implicated a small number of major signalling pathways and established theoretical limits on the number of pathway network topologies that can account for the stable spatial phase relationships of their observed signalling outputs. We further conducted perturbation analysis both experimentally and in silico, critically to assess the effects of perturbations on established patterns. We arrived at a relatively highly-constrained number of possible networks and found that these share some common motifs. Finally, we examined the dynamics of pattern appearance and discovered a core network consisting of epithelium-specific FGF and Wnt as mutually antagonistic “activators” and Shh as the “inhibitor”, which initiates the periodicity and whose existence constrains the network topology still further. Together these studies articulate the principles of multi-morphogen RD patterning and demonstrate the utility of perturbation analysis as a tool for constraining networks in this and, in principle, any RD system.

Advances in the Chromatographic Separation and Determination of Bioactive Compounds for Assessing the Nutrient Profile of Nuts

2020 ◽  
Vol 16 ◽  
Author(s):  
Natasa P. Kalogiouri ◽  
Natalia Manousi ◽  
Erwin Rosenberg ◽  
George A. Zachariadis ◽  
Victoria F. Samanidou
Keyword(s):  
Fatty Acids ◽  
Phenolic Compounds ◽  
Bioactive Compounds ◽  
High Performance ◽  
Unsaturated Fatty Acids ◽  
Nutritional Deficiencies ◽  
Analytical Technique ◽  
High Volatility ◽  
Analytical Approaches

Background:: Nuts have been incorporated into guidelines for healthy eating since they contain considerable amounts of antioxidants and their effects are related to health benefits since they contribute to the prevention of nutritional deficiencies. The micronutrient characterization is based mainly on the determination of phenolics which is the most abundant class of bioactive compounds in nuts. Terpenes constitute another class of bioactive compounds that are present in nuts and show high volatility. The analysis of phenolic compounds and terpenes are very demanding tasks that require optimization of the chromatographic conditions to improve the separation of the components. Moreover, nuts are rich in unsaturated fatty acids and they are therefore considered as cardioprotective. Gas chromatography is the predominant instrumental analytical technique for the determination of derivatized fatty acids and terpenes in food matrices, while high performance liquid chromatography is currently the most popular technique for the determination of phenolic compounds Objective:: This review summarizes all the recent advances in the optimization of the chromatographic conditions for the determination of phenolic compounds, fatty acids and terpenes in nuts Conclusion:: The state-of-the art in the technology available is critically discussed, exploring new analytical approaches to reduce the time of analysis and improve the performance of the chromatographic systems in terms of precision, reproducibility, limits of detection and quantification and overall quality of the results

scholarly journals Characterization and Quantification of Selenoprotein P: Challenges to Mass Spectrometry

2021 ◽  
Vol 22 (12) ◽  
pp. 6283
Author(s):  
Jérémy Lamarche ◽  
Luisa Ronga ◽  
Joanna Szpunar ◽  
Ryszard Lobinski
Keyword(s):  
Mass Spectrometry ◽  
State Of The Art ◽  
Animal Health ◽  
Primary Standard ◽  
Selenoprotein P ◽  
Primary Standards ◽  
Analytical Approaches ◽  
Careful Investigation ◽  
Accurate Quantification

Selenoprotein P (SELENOP) is an emerging marker of the nutritional status of selenium and of various diseases, however, its chemical characteristics still need to be investigated and methods for its accurate quantitation improved. SELENOP is unique among selenoproteins, as it contains multiple genetically encoded SeCys residues, whereas all the other characterized selenoproteins contain just one. SELENOP occurs in the form of multiple isoforms, truncated species and post-translationally modified variants which are relatively poorly characterized. The accurate quantification of SELENOP is contingent on the availability of specific primary standards and reference methods. Before recombinant SELENOP becomes available to be used as a primary standard, careful investigation of the characteristics of the SELENOP measured by electrospray MS and strict control of the recoveries at the various steps of the analytical procedures are strongly recommended. This review critically discusses the state-of-the-art of analytical approaches to the characterization and quantification of SELENOP. While immunoassays remain the standard for the determination of human and animal health status, because of their speed and simplicity, mass spectrometry techniques offer many attractive and complementary features that are highlighted and critically evaluated.

Analytical approaches to the determination of pressure distribution under a plantar prominence

1997 ◽  
Vol 12 (3) ◽  
pp. S14-S15 ◽  
Author(s):  
J. Dingwell ◽  
T. Ovaert ◽  
D. Lemmon ◽  
P.R. Cavanagh
Keyword(s):  
Pressure Distribution ◽  
Analytical Approaches

scholarly journals Approximations for the Concentration and Effectiveness Factor in Porous Catalysts of Arbitrary Shape: Taylor Series and Akbari-Ganji’s Methods

2021 ◽  
Vol 8 (4) ◽  
pp. 527-537
Author(s):  
Ramu UshaRani ◽  
Lakshmanan Rajendran ◽  
Marwan Abukhaled
Keyword(s):  
Taylor Series ◽  
Arbitrary Shape ◽  
Reaction Diffusion ◽  
Diffusion Problem ◽  
Effectiveness Factor ◽  
Michaelis Constant ◽  
Thiele Modulus ◽  
Porous Catalysts ◽  
Analytical Approaches ◽  
Analytical Expressions

A mathematical model of reaction-diffusion problem with Michaelis-Menten kinetics in catalyst particles of arbitrary shape is investigated. Analytical expressions of the concentration of substrates are derived as functions of the Thiele modulus, the modified Sherwood number, and the Michaelis constant. A Taylor series approach and the Akbari-Ganji's method are utilized to determine the substrate concentration and the effectiveness factor. The effects of the shape factor on the concentration profiles and the effectiveness factor are discussed. In addition to their simple implementations, the proposed analytical approaches are reliable and highly accurate, as it will be shown when compared with numerical simulations.

scholarly journals PENYELESAIAN KONFLIK PERTANAHAN PADA KAWASAN PARIWISATA LOMBOK (STUDI KASUS TANAH TERLANTAR DI GILI TRAWANGAN LOMBOK)

2014 ◽  
Vol 14 (2) ◽  
Author(s):  
Zainal Asikin
Keyword(s):  
Land Use ◽  
Law Enforcement ◽  
Law Enforcement Officers ◽  
Land Dispute ◽  
The People ◽  
Agrarian Law ◽  
The Government ◽  
The Right ◽  
Lombok Island

This research is aimed at exploring an appropriate solution for various conflicts in land use, particularly in optimizing the utilization of the neglected land in Gili Terawangan, Lombok Island.  This solution is required to avoid potential horizontal conflicts among people, companies and government since 1993. Conflict over land in Lombok Island in general and Gili Terawangan particularly shows several factors; first, the wrong policy in the area of land (especially in tourist areas); second, the infirm attitude of the Party and the Government Land Office in the enforcement of laws; third, the jealousy of Gili Terawangan natives as cultivators; fourth, less responsibility employers (who acquire cultivating right); fifth, the absence of law protection for Gili Terawangan natives; sixth, the arrogant attitude of law enforcement officers. The comprehensive and final resolution to the conflicts of land use could only be achieved if: (i) the people, who already control and use or manage the land from time to time, are provided certainty on managing and optimizing the land based on the principles of welfare, justice, equity, efficiency and sustainability; (ii) the selection and determination of the companies that will be granted the right to cultivate (HGU) and the right to build (HGB) should be conducted based on the transparent principle. In this respect, the government could establish an independent team that involves all components of society and higher education.Key words: land dispute, tourism area, agrarian law.

scholarly journals Determination of factor Xa inhibition doses of low-molecular heparin, nadroparin and reviparin in urological patients

2007 ◽  
Vol 64 (8) ◽  
pp. 538-542
Author(s):  
Svetlana Pavlovic ◽  
Sladjana Zivkovic ◽  
Goran Koracevic
Keyword(s):  
Factor Xa ◽  
Surgical Operation ◽  
Moderate Risk ◽  
Statistical Parameters ◽  
Nadroparin Calcium ◽  
The People ◽  
Factor Xa Inhibition ◽  
Significant Difference ◽  
Higher Doses

Background/Aim. The inhibition of factor Xa (FX) by the use of low-molecular heparin (LMH) is important clinical procedure in patients with moderate and high risk for the developament of venous thromboembolism (VTE) and pulmonary embolism (PE). The aim of this study was to determine the level of inhibition of FXa by the use of prophylactic doses of LMH nadroparin-calcium and reviparine-sodium which were applied in urological patients with moderate risk for VTE and PE. Methods. The examination included 80 urological patients divided into 4 groups after urological, uroradiological and anesthesiological preoperative preparation and categorization of anesthesiological risk according to the ASA III classification. The first two groups, of 20 patients each, received the recommended doses of LMH in accordance with the preoperative risk, and an inhibition of FXa 48 hours after the surgical operation and four hours after the administration of LMH was determined. Heptest and homogenous anti-Xa test were used for monitoring of FXa inhibition. Since the obtained anti-Xa values were not satisfactory, two more groups were formed and given double the recommended doses. In these new groups, inhibition of FXa was in recommended range. Standard descriptive statistical parameters were used for describing the charateristics of the people from the formed groups. Results. All the patients examined were clinically estimated as patients of moderate risk, for VTE and PE. There were no statistically singificant difference in body weight of the patients who received nadroparin-calcium 0.3 ml and reviparine-sodium 0.25 ml and those who received their double doses, respectively. The level of FXa inhibition in the group in which the dose of nadroparin-calcium of 0.6 ml was applied was statistically significantly higher than in the group which received the dose of 0.3 ml (Mann-Whitney U test: Z = 5.416; p < 0.0001). The level of FXa in the group given reviparine-sodium 0.5 ml was significantly higher than in the group which received the half of this dose (Mann-Whitney U test: Z = 5.416; p < 0.0001). This research did not confirm a statistically significant difference in the levels of FXa inhibition in patients who received nadroparincalcium as VTE and PE prophilaxis in the dose of 0.6 ml and those who received reviparin-sodium 0.5 ml (in two doses of 0.25 ml) (Mann-Whitney U test: Z = 0.163; p > 0.05). Conclusion. According to biochemical monitoring, the recommended doses of LMH are insufficient for the prophylactic inhibition of FXa in urological pateints with moderate risk for VTE and PE, so the higher doses which inhibit FXa are recommended. .

scholarly journals ARAH BARU KAJIAN TAFSIR: KAJIAN METODOLOGI PENELITIAN AKSIN WIJAYA DALAM KARYANYA SEJARAH KENABIAN PERSPEKTIF TAFSIR NUZULI MUHAMMAD IZZAT DARWAZAH

QOF ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 161-174
Author(s):  
Cholid Ma'arif
Keyword(s):  
Research Methods ◽  
Family Life ◽  
Research Methodology ◽  
Comparative Research ◽  
The People ◽  
Four Books ◽  
Interpretation Method ◽  
The Ideal

Abstrak This paper will explore aspects of research methodology of exegesis written by Aksin Wijaya related to methods nuzuli ala Muhammad Izzat Darwazah. For that, the focus of this discussion is the methodology of his research in his own book of under title Sejarah Kenabian Dalam Perspektif Tafsir Nuzuli Muhammad Izzat Darwazah, finding out how people review mufassir. Specifically, the methodical determination of the previous his experienced has moved soon of orientation from the critical to the descriptive while facing of four books, namely: Tafsir al Hadith, 'Ashr al Nabiy wa Biatuhu Qabla al Bi'tsah, Sirah al Rasul; Suwar Muqtabasah min al Qur'an, and ad Dustur al Qur'an fi Su'uni al Hayat works of thinkers and historians. From his reading, he at least analyzes his views into two important parts, namely; 1) the interpretation method of nuzuli and the ideal concept it contains, 2) it then draws it into the realm of pre-Islamic, personal and family life of the prophet Muhammad, to the condition of the people of prophetic era through the perspective of nuzuli Izzat Darwazah exegesis. According to the reviewer, there are other research elements in writing the work of the exegesis, namely some models of research methods of interpretation at once, such as: comparative research, character research, and thematic-nuzuli research. Whereas although placed more as an overview of nuzuli interpretation, at least he invites readers, especially in Indonesia to re-read the tafsir nuzuli treasury and see which is as worthy to be developed in the turats of Islam Nusantara. Abstrak Tulisan ini hendak menelusuri aspek metodologi penelitian tafsir yang dilakukan oleh Dr. Aksin Wijaya terkait metode nuzuli ala Muhammad Izzat Darwazah. Untuk itu, fokus dari pembahasan ini adalah tentang metodologi penelitiannya dalam buku berjudul Sejarah Kenabian Dalam Perspektif Tafsir Nuzuli Muhammad Izzat Darwazah untuk mengetahui bagaimana orang mengkaji mufassir. Dimana secara khusus mulai penentuan metodis dari sebelumnya ia mengalami pergeseran orientasi dari kritis ke deskriptif dalam menghadapi empat kitab hasil perburuannya, yaitu: Tafsir al Hadits, ‘Ashr al Nabiy wa Biatuhu Qabla al Bi’tsah, Sirah al Rasul; Suwar Muqtabasah min al Qur’an, dan ad Dustur al Qur’an fi Su’uni al Hayat karya tokoh pemikir dan sejarawan. Dari pembacaannya tersebut, ia setidaknya menganalisa pandangannya menjadi dua bagian penting, yaitu; 1) metode tafsir nuzuli dan konsep ideal yang dikandungnya, 2) kemudian ia menariknya ke ranah kehidupan masyarakat pra-islam, pribadi dan keluarga nabi Muhammad saw, hingga kondisi masyarakat era kenabian melalui perspektif tafsir nuzuli Izzat Darwazah. Pun demikian, menurut penulis ada unsur penelitian lain dalam penulisan karya Aksin tersebut, yaitu beberapa model metode penelitian tafsir sekaligus, seperti: penelitian perbandingan, penelitian tokoh, dan penelitian tematik-nuzuli. Dimana walaupun diletakkan lebih sebagai gambaran umum tafsir nuzuli, setidaknya ia mengajak pembaca khususnya di Indonesia untuk meneelaah kembali khazanah tafsir nuzuli dan memandang mana yang sekira layak untuk dikembangkan dalam turats Islam ke-Indonesia-an.

scholarly journals Strengthening the Marine Defense Strategy of Lanal Banten Area through Empowerment of the Traffic Separation Scheme in the Sunda Strait

2021 ◽  
Author(s):  
Mohamad Rachmad ◽  
Suhirwan ◽  
Ansori Zaini ◽  
Ernalem Bangun ◽  
Lukman Yudho Prakos ◽  
...  
Keyword(s):  
Policy Implementation ◽  
Geographical Location ◽  
Separation Scheme ◽  
Special Operations ◽  
Defense Strategy ◽  
Indonesian Archipelago ◽  
Archipelago Sea ◽  
The People ◽  
Malacca Strait

Indonesia as an archipelagic country is gifted by God with a geographical location between two continents and also two oceans, making Indonesia's position very strategic. In accordance with UNCLOS 1982, as an archipelagic country, Indonesia has an obligation to provide a shipping route called ALKI (Indonesian Archipelago Sea Channel). ALKI 1 stretches from the Malacca Strait to the Sunda Strait. The Sunda Strait as one of the busy shipping lanes is vulnerable to various forms of threats. To ensure the safety of shipping in the Sunda Strait, the TSS of the Sunda Strait is designated as a shipping lane separating channel. With the determination of the TSS of the Sunda Strait, shipping using the Sunda Strait will be increasingly crowded, this will pose an even greater threat. The purpose of this study was to analyze the strengthening of the marine defense strategy in the Sunda Strait carried out by Lanal Banten by utilizing the TSS of the Sunda Strait. The method used in this research is descriptive qualitative research using the theory of policy implementation from Van Meter Van Horn and strategy theory from Lykke. The results of the study indicate that the lack of facilities and infrastructure and the absence of a special operation carried out by the Indonesian Navy to secure the Sunda Strait, so that the implementation of strengthening the marine defense strategy in the Sunda Strait has not been optimal. There needs to be support for facilities and infrastructure as well as support for special operations in the Sunda Strait to strengthen the maritime defense strategy in the Sunda Strait and the participation of the people around the Sunda Strait.

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