scholarly journals Two-Generation Analysis of Pollen Flow Across a Landscape. IV. Estimating the Dispersal Parameter

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 355-363
Author(s):  
Frédéric Austerlitz ◽  
Peter E Smouse
Keyword(s):  
Adult Population ◽  
Pollen Dispersal ◽  
Dispersal Distance ◽  
The Novel ◽  
Sample Sizes ◽  
Plant Populations ◽  
Global Estimate ◽  
Independent Estimate ◽  
Pollen Movement ◽  
Better Than

Abstract The distance of pollen movement is an important determinant of the neighborhood area of plant populations. In earlier studies, we designed a method for estimating the distance of pollen dispersal, on the basis of the analysis of the differentiation among the pollen clouds of a sample of females, spaced across the landscape. The method was based solely on an estimate of the global level of differentiation among the pollen clouds of the total array of sampled females. Here, we develop novel estimators, on the basis of the divergence of pollen clouds for all pairs of females, assuming that an independent estimate of adult population density is available. A simulation study shows that the estimators are all slightly biased, but that most have enough precision to be useful, at least with adequate sample sizes. We show that one of the novel pairwise methods provides estimates that are slightly better than the best global estimate, especially when the markers used have low exclusion probability. The new method can also be generalized to the case where there is no prior information on the density of reproductive adults. In that case, we can jointly estimate the density itself and the pollen dispersal distance, given sufficient sample sizes. The bias of this last estimator is larger and the precision is lower than for those estimates based on independent estimates of density, but the estimate is of some interest, because a meaningful independent estimate of the density of reproducing individuals is difficult to obtain in most cases.

scholarly journals Two-generation analysis of pollen flow across a landscape. III. Impact of adult population structure

2001 ◽  
Vol 78 (3) ◽  
pp. 271-280 ◽  
Author(s):  
FRÉDÉRIC AUSTERLITZ ◽  
PETER E. SMOUSE
Keyword(s):  
Genetic Structure ◽  
Adult Population ◽  
Pollen Dispersal ◽  
Simple Relation ◽  
Physical Distance ◽  
Dispersal Distance ◽  
Analytical Theory ◽  
Pollen Flow ◽  
Estimation Errors ◽  
Spatially Distributed

The rate and distance of instantaneous pollen flow in a population are parameters of considerable current interest for plant population geneticists and conservation biologists. We have recently developed an estimator (Φft) of differentiation between the inferred pollen clouds that fertilize several females, sampled within a single population. We have shown that there is a simple relation between Φft and the average pollen dispersal distance (δ) for the case of a population with no geographic structure. Though forest trees usually show considerable pollen flow, assuming an absence of spatially distributed genetic structure is not always wise. Here, we develop analytical theory for the relation between Φft and δ, for the case where the probability of Identity by Descent (IBD) for two individuals decreases with the physical distance between them. This analytical theory allows us to provide an effective method for estimating pollen dispersal distance in a population with adult genetic structure. Using real examples, we show that estimation errors can be large if genetic structure is not taken into account, so it is wise to evaluate adult genetic structure simultaneously with estimation of Φft for the pollen clouds. We show that the results are only moderately affected by changes in the decay function, a result of some importance since no completely established theory is available for this function.

scholarly journals The role of self-incompatibility systems in the prevention of bi-parental inbreeding

2017 ◽  
Author(s):  
Tara N Furstenau ◽  
Reed A Cartwright
Keyword(s):  
Inbreeding Depression ◽  
Pollen Dispersal ◽  
Dispersal Distance ◽  
Inbreeding Avoidance ◽  
Self Incompatibility ◽  
Plant Populations ◽  
Population Sizes ◽  
Self Fertilization ◽  
Individual Based Simulation

Hermaphroditic plants experience inbreeding through both self-fertilization and bi-parental inbreeding. Therefore, many plant species have evolved either heteromorphic (morphology-based) or homomorphic (molecular-based) self-incompatibility (SI) systems. These SI systems limit extreme inbreeding through self-fertilization and, in the case of homomorphic SI systems, have the potential to limit bi-parental inbreeding, which is common when dispersal is restricted to a local region. Homomorphic SI species are prevalent across the angiosperms, and it is often assumed that the potential to reduce bi-parental inbreeding may be a factor in their success. To test this assumption, we developed a spatially-explicit, individual-based simulation of plant populations with either heteromorphic SI or one of three different types of homomorphic SI. In our simulations, we varied dispersal distance and the presence of inbreeding depression. We found that autozygosity in the homomorphic SI populations was significantly lower than in the heteromorphic SI populations and that this reduction was due to bi-parental inbreeding avoidance. As expected, the differences between the homomorphic and heteromorphic SI populations were more pronounced when seed and pollen dispersal was limited. However, levels of homozygosity and inbreeding depression between these plant populations were not different. At low dispersal, homomorphic SI populations also suffered reduced female fecundity and had smaller census population sizes. Our results suggest that bi-parental inbreeding avoidance was unlikely to be a major driver in the evolution of homomorphic SI systems.

scholarly journals The role of self-incompatibility systems in the prevention of bi-parental inbreeding

2017 ◽  
Author(s):  
Tara N Furstenau ◽  
Reed A Cartwright
Keyword(s):  
Inbreeding Depression ◽  
Pollen Dispersal ◽  
Dispersal Distance ◽  
Inbreeding Avoidance ◽  
Self Incompatibility ◽  
Plant Populations ◽  
Population Sizes ◽  
Self Fertilization ◽  
Individual Based Simulation

Hermaphroditic plants experience inbreeding through both self-fertilization and bi-parental inbreeding. Therefore, many plant species have evolved either heteromorphic (morphology-based) or homomorphic (molecular-based) self-incompatibility (SI) systems. These SI systems limit extreme inbreeding through self-fertilization and, in the case of homomorphic SI systems, have the potential to limit bi-parental inbreeding, which is common when dispersal is restricted to a local region. Homomorphic SI species are prevalent across the angiosperms, and it is often assumed that the potential to reduce bi-parental inbreeding may be a factor in their success. To test this assumption, we developed a spatially-explicit, individual-based simulation of plant populations with either heteromorphic SI or one of three different types of homomorphic SI. In our simulations, we varied dispersal distance and the presence of inbreeding depression. We found that autozygosity in the homomorphic SI populations was significantly lower than in the heteromorphic SI populations and that this reduction was due to bi-parental inbreeding avoidance. As expected, the differences between the homomorphic and heteromorphic SI populations were more pronounced when seed and pollen dispersal was limited. However, levels of homozygosity and inbreeding depression between these plant populations were not different. At low dispersal, homomorphic SI populations also suffered reduced female fecundity and had smaller census population sizes. Our results suggest that bi-parental inbreeding avoidance was unlikely to be a major driver in the evolution of homomorphic SI systems.

A Set-theoretic Approach to Reasoning Services for the Description Logic 𝒟 ℒ D 4,×

2020 ◽  
Vol 176 (3-4) ◽  
pp. 349-384
Author(s):  
Domenico Cantone ◽  
Marianna Nicolosi-Asmundo ◽  
Daniele Francesco Santamaria
Keyword(s):  
Description Logic ◽  
Description Logics ◽  
Theoretic Approach ◽  
The Novel ◽  
Data Types ◽  
Left Hand ◽  
Rule Languages ◽  
Tableau System ◽  
High Scalability ◽  
Better Than

In this paper we consider the most common TBox and ABox reasoning services for the description logic 𝒟ℒ〈4LQSR,x〉(D) ( 𝒟 ℒ D 4,× , for short) and prove their decidability via a reduction to the satisfiability problem for the set-theoretic fragment 4LQSR. 𝒟 ℒ D 4,× is a very expressive description logic. It combines the high scalability and efficiency of rule languages such as the SemanticWeb Rule Language (SWRL) with the expressivity of description logics. In fact, among other features, it supports Boolean operations on concepts and roles, role constructs such as the product of concepts and role chains on the left-hand side of inclusion axioms, role properties such as transitivity, symmetry, reflexivity, and irreflexivity, and data types. We further provide a KE-tableau-based procedure that allows one to reason on the main TBox and ABox reasoning tasks for the description logic 𝒟 ℒ D 4,× . Our algorithm is based on a variant of the KE-tableau system for sets of universally quantified clauses, where the KE-elimination rule is generalized in such a way as to incorporate the γ-rule. The novel system, called KEγ-tableau, turns out to be an improvement of the system introduced in [1] and of standard first-order KE-tableaux [2]. Suitable benchmark test sets executed on C++ implementations of the three mentioned systems show that in several cases the performances of the KEγ-tableau-based reasoner are up to about 400% better than the ones of the other two systems.

scholarly journals Design of a Novel Six-Axis Wrist Force Sensor

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3120 ◽  
Author(s):  
Shanshan Hu ◽  
Huaiyang Wang ◽  
Yong Wang ◽  
Zhengshi Liu
Keyword(s):  
Simulation Analysis ◽  
Dynamic Performance ◽  
Force Sensor ◽  
The Novel ◽  
Element Analysis ◽  
Body Design ◽  
Design Idea ◽  
Bridge Circuits ◽  
Design Ideas ◽  
Better Than

A novel elastic body design idea of six-axis wrist force sensor with a floating beam was raised based on the analysis of the robot six-axis wrist force sensor with a floating beam. The design ideas improve the sensor’s dynamic performance significantly, while not reducing its sensitivity. First, the design ideas were described in detail, which were analyzed by mechanical modeling and were verified by finite element analysis. Second, the static simulation analysis of the novel elastomer of sensor was carried out. According to the strain distribution performance, the position of the strain gauges pasted and the connection mode of the full-bridge circuits were decided, which can achieve theoretical decoupling. Finally, the comparison between the static and dynamic performance of the novel sensor and the original sensor with floating beams was done. The results show that the static and dynamic performance of the novel six-axis wrist sensor are all better than the original sensor.

scholarly journals The Upsurge and Impact of COVID 19 in India: Health Issues and Remedial Measures

2021 ◽  
pp. 28-34
Author(s):  
Kanchi Isswani
Keyword(s):  
Sudden Increase ◽  
The Novel ◽  
Health Issues ◽  
Public Places ◽  
Frontline Workers ◽  
Time Period ◽  
Essential Services ◽  
Novel Coronavirus ◽  
Major Decision ◽  
Better Than

The novel Coronavirus was something that nobody was prepared for. It was that part of the syllabus which was always neglected. The contagious disease which started in the Wuhan region of China had started to settle in various parts of the World. The outbreak of this disease has reached such a huge number that all the countries witnessed lockdown in some form or the other. Some people have witnessed destruction of mankind while some have even leisured this time to their fullest but as it has been always said “Prevention is better than cure”. Prevention of covid 19 in all the nations was one of the major steps which was taken in the year 2020. In India it all started in the year of 2019 December when the first ever case of covid 19 was reported in the state of Kerala followed by Rajasthan, Maharashtra and Delhi. Following such a situation and then sudden increase in the no of cases all over the country a major decision was taken that was of Complete lockdown excluding the emergency and essential services. Before taking the step of lockdown, as a gesture of respect to the frontline workers, government of India announced Tali Bajao movement. In the period of lockdown Certain norms were even made mandatory that were wearing a mask, maintenance of hand sanitation and following social distancing of 1.5 meters in public places. All the educational institutes and teachings were even suspended during the time period of lockdown as it could have become a hub for the virus to spread. With time, the restrictions which were laid down in lockdown were started to be reduced in the phase wise manner and finally India noticed its very first Unlock period. In all this scenario mankind has dealt with various situations and have emerged to be a better person. All these steps were crucial to control the spread of Novel Coronavirus and prevention from the already spread cases.

scholarly journals The performance of anthropometric measures to predict diabetes mellitus and hypertension among adults in Jordan

2019 ◽  
Author(s):  
Yousef Khader ◽  
Anwar Batieha ◽  
Hashem Jaddou ◽  
Mohammad El-Khateeb ◽  
Kamel Ajlouni
Keyword(s):  
Adult Population ◽  
Population Based ◽  
Hip Circumference ◽  
Anthropometric Measures ◽  
Study Objective ◽  
Biochemical Measurements ◽  
Diagnosed Diabetes ◽  
Newly Diagnosed Diabetes ◽  
Better Than ◽  
Structured Questionnaire

Abstract Objectives This study aimed to evaluate and compare the abilities of waist circumference (WC), body mass index (BMI), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) to predict recently and previously diagnosed diabetes and hypertension and assess their appropriate cut-off values among Jordanian adults.Methods Data from the 2017 cardiovascular risk factors survey were analyzed to achieve the study objective. The survey collected extensive data from a national population-based sample of Jordanian residents. A structured questionnaire was used to collect sociodemographic variables and clinical data. Blood samples were taken for biochemical measurements. Anthropometric characteristics were measured by the same team of trained field researchers.Results This study included a total of 1193 men and 2863 women. Their age ranged from 18 to 90 year with a mean (SD) of 43.8 (14.2) year. WHtR performed better than other anthropometric measures and had a good accuracy (AUC>0.80) among women and fair accuracy among men to predict newly diagnosed diabetes and previously diagnosed diabetes and hypertension. The appropriate cut-off points for anthropometric measures among women were 92 cm form WC, 104 cm for HC, 30 Kg/m 2 for BMI, 0.85 for WHR, and 0.60 for WHtR. For men, the appropriate cut-off points were 100 cm for WC, 104 cm for HC, 27 Kg/m 2 for BMI, 0.93 for WHR, and 0.57 for WHtR.Conclusion WHtR performed better than other anthropometric measures in predicting diabetes and hypertension among adult population in Jordan. We recommend WHtR as a measure of choice with a cut-off value of 0.6 for women and 0.57 for men to predict diabetes and hypertension among Jordanians.

scholarly journals “Concepts of Konstantine Gamsakhurdia`s “Moon`s Abduction”

2021 ◽  
Author(s):  
Nana Kutsia ◽  
Miranda Todua ◽  
Marine Turava
Keyword(s):  
State Building ◽  
The Novel ◽  
Soviet System ◽  
Security Officer ◽  
World Outlook ◽  
The World ◽  
Literary Heritage ◽  
Educated Person ◽  
Better Than ◽  
Positive Character

“Moon`s Abduction” by Konstantine Gamsakhurdia is a very important text written in the Soviet Georgia. The writer created monumental literary landscape in the period of so called “socialist realism” literary style. The novel makes a great demand on the reader`s erudition, on his capacity to understand the complex allusions, literary, philosophical and mythological, that characterize Gamsakhurdia`s prose. The present article deals with the world-outlook of Soviet and Post-Soviet literary critique – on the background of the publicistic letters of the outstanding critics Beso Zhghenti and Soso Sigua. The novel clears up the writer`s attitude to the revolution, socialism, collectivization of agriculture, person`s role as a member of society. The Soviet and Post-Soviet critics world-outlooks are absolutely different. By the Soviet critic (Beso Zhghenti) the novel is an excessive apologia of Soviet system, of Soviet state-building, a positive character (hero) is Arzakan Zvambaia, the security officer, the ossicial of Cheka, Bolshevism is better than traditional life of Georgia, civilization is better than culture. By the Post-Soviet world-outlook (Soso Sigua) the novel is a reflection of tragedy of the Georgian nation (because of negation of Georgian traditions, unique Georgian culture), a positive character is a prince Tarash Emkhvari, cultural and well-educated person; Bolshevizm is tragedy. Literary, philosophical and mythological allusions characterize Gamsakhurdias literary heritage (verses, short-stories, novels). The article deals with the world-outlook of the author. The official of Cheka Arzakan is a patricide, another official Arlan cut the centuries-old sacral tree - Bolhevizm hates roots and traditions. There are a lot of mythological characters reflected in the novel (Aramkhutu-Amirani, Sacral-tree, Mezir – Sacral serpant…). A reader feels the influence of Nitcze and Bergson world-outlook, passages from Hesiod`s “Theogony” and Appolonios from Rodoss “Argonautica.”The novel of Konstantine Gamsakhurdia is one of the best reflections and the best samples of Georgian novel of the 30s of the 20th century epoch.

scholarly journals Sesquiterpenes and Cyclodepsipeptides from Marine-Derived Fungus Trichoderma longibrachiatum and Their Antagonistic Activities against Soil-Borne Pathogens

Marine Drugs ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 165 ◽  
Author(s):  
Feng-Yu Du ◽  
Guang-Lin Ju ◽  
Lin Xiao ◽  
Yuan-Ming Zhou ◽  
Xia Wu
Keyword(s):  
Phytopathogenic Fungi ◽  
Economic Losses ◽  
The Novel ◽  
Root Knot Nematode ◽  
Trichoderma Longibrachiatum ◽  
Soil Borne Pathogens ◽  
Antifungal Potential ◽  
Antagonistic Potential ◽  
Southern Root Knot Nematode ◽  
Better Than

Soil-borne pathogens, including phytopathogenic fungi and root-knot nematodes, could synergistically invade vegetable roots and result in serious economic losses. The genus of Trichoderma has been proven to be a promising reservoir of biocontrol agents in agriculture. In this study, the search for antagonistic metabolites from a marine-derived fungus, Trichoderma longibrachiatum, obtained two structural series of sesquiterpenes 1–6 and cyclodepsipeptides 7–9. Notably, the novel 1 was a rare norsesquiterpene characterized by an unprecedented tricyclic-6/5/5-[4.3.1.01,6]-decane skeleton. Their structures were elucidated by extensive spectroscopic analyses, while the absolute configuration of novel 1 was determined by the comparison of experimental and calculated ECD spectra. The novel 1 and known 2 and 3 showed significant antifungal activities against Colletotrichum lagrnarium with MIC values of 8, 16, and 16 μg/mL respectively, even better than those of the commonly used synthetic fungicide carbendazim with 32 μg/mL. They also exhibited antifungal potential against carbendazim-resistant Botrytis cinerea. Cyclodepsipeptides 7–9 showed moderate nematicidal activities against the southern root-knot nematode (Meloidogyne incognita). This study constitutes the first report on the antagonistic effects of metabolites from T. Longibrachiatum against soil-borne pathogens, also highlighting the integrated antagonistic potential of marine-derived T. Longibrachiatum as a biocontrol agent.

Staying close: short local dispersal distances on a managed forest of two Patagonian Nothofagus species

2020 ◽  
Vol 93 (5) ◽  
pp. 652-661 ◽  
Author(s):  
Georgina Sola ◽  
Verónica El Mujtar ◽  
Leonardo Gallo ◽  
Giovanni G Vendramin ◽  
Paula Marchelli
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Pollen Dispersal ◽  
Dispersal Distance ◽  
Restricted Gene Flow ◽  
Fine Scale ◽  
Gene Dispersal ◽  
Mature Trees ◽  
The Impact

Abstract Understanding the impact of management on the dispersal potential of forest tree species is pivotal in the context of global change, given the implications of gene flow on species evolution. We aimed to determine the effect of logging on gene flow distances in two Nothofagus species from temperate Patagonian forests having high ecological relevance and wood quality. Therefore, a total of 778 individuals (mature trees and saplings) of Nothofagus alpina and N. obliqua, from a single plot managed 20 years ago (2.85 hectares), were mapped and genotyped at polymorphic nuclear microsatellite loci. Historical estimates of gene dispersal distance (based on fine-scale spatial genetic structure) and contemporary estimates of seed and pollen dispersal (based on spatially explicit mating models) were obtained. The results indicated restricted gene flow (gene distance ≤ 45 m, both pollen and seed), no selfing and significant seed and pollen immigration from trees located outside the studied plot but in the close surrounding area. The size of trees (diameter at breast height and height) was significantly associated with female and/or male fertility. The significant fine-scale spatial genetic structure was consistent with the restricted seed and pollen dispersal. Moreover, both estimates of gene dispersal (historical and contemporary) gave congruent results. This suggests that the recent history of logging within the study area has not significantly influenced on patterns of gene flow, which can be explained by the silviculture applied to the stand. The residual tree density maintained species composition, and the homogeneous spatial distribution of trees allowed the maintenance of gene dispersal. The short dispersal distance estimated for these two species has several implications both for understanding the evolution of the species and for defining management, conservation and restoration actions. Future replication of this study in other Nothofagus Patagonian forests would be helpful to validate our conclusions.

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