scholarly journals On Mautner-Type Probability of Capture of Intergalactic Meteor Particles by Habitable Exoplanets

Sci ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 47 ◽  
Author(s):  
Andjelka Kovacevic
Keyword(s):  
Rare Events ◽  
Particle Capture ◽  
Transient Distribution ◽  
Probability Map ◽  
Habitable Zones ◽  
Source Populations ◽  
Dynamical Description ◽  
The Impact ◽  
Bio Material ◽  
Probability Of Capture

Both macro and microprojectiles (e.g., interplanetary, interstellar and even intergalactic material)are seen as important vehicles for the exchange of potential (bio)material within our solar system as wellas between stellar systems in our Galaxy. Accordingly, this requires estimates of the impact probabilitiesfor different source populations of projectiles, including for intergalactic meteor particles which havereceived relatively little attention since considered as rare events (discrete occurrences that are statisticallyimprobable due to their very infrequent appearance). We employ the simple but yet comprehensivemodel of intergalactic microprojectile capture by the gravity of exoplanets which enables us to estimatethe map of collisional probabilities for an available sample of exoplanets in habitable zones around hoststars. The model includes a dynamical description of the capture adopted from Mautner model ofinterstellar exchange of microparticles and changed for our purposes. We use statistical and informationmetrics to calculate probability map of intergalactic meteorite particle capture. Moreover, by calculatingthe entropy index map we measure the concentration of these rare events. We further adopted a modelfrom immigration theory, to show that the transient distribution of birth/death/immigration of materialfor the simplest case has a high value.

scholarly journals On Mautner-Type Probability of Capture of Intergalactic Meteor Particles by Habitable Exoplanets

Sci ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 40
Author(s):  
Andjelka B. Kovačević
Keyword(s):  
Rare Events ◽  
Transient Distribution ◽  
Habitable Zones ◽  
Source Populations ◽  
Dynamical Description ◽  
The Impact ◽  
Host Stars ◽  
Information Metrics ◽  
Bio Material ◽  
Probability Of Capture

Both macro and microprojectiles (e.g., interplanetary, interstellar and even intergalactic material) are seen as an important vehicle for the exchange of (bio)material within our solar system as well as between stellar systems in our Galaxy. Accordingly, this requires estimates of the impact probabilities for different source populations of projectiles, specifically for intergalactic meteor particles which have received relatively little attention since considered as rare events (discrete occurrences that are statistically improbable due to their very infrequent appearance). We employ the simple but yet comprehensive model of intergalactic microprojectile capture by the gravity of exoplanets which enables us to estimate the map of collisional probabilities for an available sample of exoplanets in habitable zones around host stars. The model includes a dynamical description of the caption adopted from Mautner model of interstellar exchange of microparticles and changed for our purposes. We use statistical and information metrics to calculate probability map of intergalactic meteorite particle capture. Moreover, by calculating the entropy index map we measure the concentration of these rare events. By adopting a model from immigration theory, we show that the transient distribution of birth/death/immigration of material for the simplest case has a high value.

scholarly journals On Mautner-Type Probability of Capture of Intergalactic Meteor Particles by Habitable Exoplanets

Sci ◽  
2019 ◽  
Vol 1 (3) ◽  
pp. 61
Author(s):  
Andjelka B. Kovačević
Keyword(s):  
Single Molecule ◽  
Rare Events ◽  
Birth And Death Processes ◽  
Habitable Zones ◽  
Source Populations ◽  
Dynamical Description ◽  
The Impact ◽  
Near Future ◽  
Host Stars ◽  
Information Metrics

Both macro and microprojectiles (e.g., interplanetary, interstellar and even intergalactic material) are seen as important vehicles for the exchange of potential (bio)material within our solar system as well as between stellar systems in our Galaxy. Accordingly, this requires estimates of the impact probabilities for different source populations of projectiles, including for intergalactic meteor particles which have received relatively little attention since considered as rare events (discrete occurrences that are statistically improbable due to their very infrequent appearance). We employ the simple but comprehensive model of intergalactic microprojectile capture by the gravity of exoplanets which enables us to estimate the map of collisional probabilities for an available sample of exoplanets in habitable zones around host stars. The model includes a dynamical description of the capture adopted from Mautner model of interstellar exchange of microparticles and changed for our purposes. We use statistical and information metrics to calculate probability map of intergalactic meteorite particle capture. Moreover, by calculating the entropy index map we estimate the concentration of these rare events. We further adopted a model from immigration theory, to show that the time dependent distribution of single molecule immigration of material indicates high survivability of the immigrated material taking into account birth and death processes on our planet. At present immigration of material can not be observationally constrained but it seems reasonable to think that it will be possible in the near future, and to use it along other proposed parameters for life sustainability on some planet.

Fire and its impact on avian population dynamics

1997 ◽  
Vol 3 (3) ◽  
pp. 206 ◽  
Author(s):  
G. Barry Baker ◽  
E. Belinda Dettmann ◽  
Stephen J. Wilson
Keyword(s):  
Population Size ◽  
Fire Regimes ◽  
Long Term Study ◽  
Sclerophyll Forest ◽  
In Fire ◽  
Avian Populations ◽  
The Impact ◽  
Term Monitoring ◽  
Probability Of Capture

Survival rate, population size, recruitment and probability of capture, derived from a long-term study of 20 passerine species in wet sclerophyll forest near Canberra, were used to measure the impact of a high intensity wildfire which burnt 70% of the study area. The wildfire significantly affected the population size of 13 species for a period of up to six years following the fire. Survival and recruitment were the least sensitive measures of impact and indicated a significant response to fire for only 2 of 10 species. We detected measurable effects of the fire for 17 of the 20 species studied. Many of these species had returned to prefire levels within three years, but for nine species the effects were still apparent six years later. Mark-recapture methodology provides an effective way of measuring the impact of fire regimes in forest environments. Long-term monitoring programmes should be established in fire-prone forest environments to contribute toward our understanding of fire, and its effect on avian populations. Such programmes have resource implications and researchers are urged to encourage the participation of the amateur bird banding community to contribute to such projects.

Competing Swarms of Autonomous Vehicles: Intruders Versus Guardians

2017 ◽  
Author(s):  
Daigo Shishika ◽  
Katarina Sherman ◽  
Derek A. Paley
Keyword(s):  
Protected Area ◽  
Autonomous Vehicles ◽  
Payoff Function ◽  
Time Interval ◽  
Design Strategies ◽  
Time Intervals ◽  
Aerial Vehicles ◽  
Zero Sum ◽  
The Impact ◽  
Probability Of Capture

We consider a competition between two swarms of aerial vehicles, where multiple intruder vehicles try to approach and then leave an area that multiple guardian vehicles are protecting. Pre-existing swarming strategies for the guardians to maximize the probability of capturing a single intruder are summarized. This work considers the case where multiple intruders approach the protected area sequentially with varied time intervals, to study the impact of intrusion frequency on the probability of capture. In addition, we formulate a payoff function treating the competition as a zero-sum game, and use this function to design strategies for the intruders, i.e., how to optimize the time interval between intrusions. We propose an intrusion strategy and demonstrate its performance with numerical simulations.

scholarly journals Impact strength of surface treated SS316L wires reinforced PMMA**

2021 ◽  
Vol 30 (1) ◽  
pp. 272-278
Author(s):  
Sarmad A. Ibrahim ◽  
Sadeq H. Lafta ◽  
Wafaa A. Hussain
Keyword(s):  
Stainless Steel ◽  
Impact Strength ◽  
Ethylene Glycol ◽  
Low Cost ◽  
Wire Surface ◽  
Stainless Steel 316L ◽  
Cost Surface ◽  
The Impact ◽  
Graphite Rod ◽  
Bio Material

Abstract Stainless steel 316L (SS316L) as a significant bio-material, their wires were used to support the PMMA matrix. Two simple and low-cost surface pretreatments for SS316L wires were performed to enhance denture impact strength: mechanical scratching (treating SS316L wires with SiC powder inside a rotating container) and electrochemical anodizing. Three mechanical scratching samples for different periods of 60, 90 and 120min were prepared. Anodizing technique conditions were: Ethylene glycol with perchloric acid as an anodizing solution, 15V supplying and graphite rod as an anode. Anodizing process involved three pretreating periods of 15, 20, and 30min. All the prepared samples had dimensions of 65 × 10 × 3 mm. SEM technique showed different morphology nature involved holes, scratches and pores with a density of 104/μm2 and a crack length of 60μm. The PMMA reinforced with scratched stainless steel 316L wire surface for 120 min presented the highest impact strength value (42 kJ/m2) with (450.91%) increment. Anodizing samples showed a fluctuating behavior of samples with enhancing in the impact strength of anodizing wire for 20min of about 26.99 kJ/m2, which is still lower than that for scratched samples in average.

Genetic viability of a reintroduced population of south-western common brushtail possum (Trichosurus vulpecula hypoleucus), Western Australia

2020 ◽  
Vol 26 (3) ◽  
pp. 282
Author(s):  
Lara Semple ◽  
Kym Ottewell ◽  
Colleen Sims ◽  
Henner Simianer ◽  
Margaret Byrne
Keyword(s):  
Genetic Diversity ◽  
Western Australia ◽  
Sign Test ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Tissue Samples ◽  
Reintroduced Population ◽  
Common Brushtail Possum ◽  
Source Populations ◽  
The Impact

This study focused on a reintroduced population of south-western common brushtail possum (Trichosurus vulpecula hypoleucus) to assess genetic variability and inform future management strategies. Individuals were translocated to Matuwa Kurarra-Kurarra Indigenous Protected Area, Western Australia, from four source populations, but subsequent monitoring has indicated a 50% reduction in population size from original founder numbers in the eight years since establishment. Tissue samples from three of the four source populations and an additional four comparative sites (n=140 animals total) were analysed using 13 microsatellite loci. Inbreeding was lower and heterozygosity was higher in the translocated Matuwa population than in two of the source populations studied, highlighting the benefits of promoting outbreeding through the use of multiple source populations in translocations. However, allelic richness at Matuwa is low relative to two of the source populations, suggesting the impact of population bottlenecks on genetic diversity, which was supported by significant allele frequency mode shift and Wilcoxon rank sign test for heterozygosity excess tests for genetic bottlenecks. Despite the genetic health of the population being stronger than predicted, this population is still at risk due to environmental factors, small size and fragmentation. This is the first study to document patterns of genetic diversity and to highlight issues with translocation for this subspecies and adds to the limited literature illustrating how outbreeding can be used for conservation purposes.

scholarly journals Genetic Consequences of Multiple Translocations of the Banded Hare-Wallaby in Western Australia

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 448
Author(s):  
Daniel J. White ◽  
Kym Ottewell ◽  
Peter B. S. Spencer ◽  
Michael Smith ◽  
Jeff Short ◽  
...  
Keyword(s):  
Western Australia ◽  
Allelic Diversity ◽  
Population Viability Analysis ◽  
High Survival ◽  
Mammal Species ◽  
Viability Analysis ◽  
Invasive Predators ◽  
Source Populations ◽  
Environmental Events ◽  
The Impact

Many Australian mammal species now only occur on islands and fenced mainland havens free from invasive predators. The range of one species, the banded hare-wallaby (Lagostrophus fasciatus), had contracted to two offshore islands in Western Australia. To improve survival, four conservation translocations have been attempted with mixed success, and all occurred in the absence of genetic information. Here, we genotyped seven polymorphic microsatellite markers in two source (Bernier Island and Dorre Island), two historic captive, and two translocated L. fasciatus populations to determine the impact of multiple translocations on genetic diversity. Subsequently, we used population viability analysis (PVA) and gene retention modelling to determine scenarios that will maximise demographic resilience and genetic richness of two new populations that are currently being established. One translocated population (Wadderin) has undergone a genetic bottleneck and lost 8.1% of its source population’s allelic diversity, while the other (Faure Island) may be inbred. We show that founder number is a key parameter when establishing new L. fasciatus populations and 100 founders should lead to high survival probabilities. Our modelling predicts that during periodic droughts, the recovery of source populations will be slower post-harvest, while 75% more animals—about 60 individuals—are required to retain adequate allelic diversity in the translocated population. Our approach demonstrates how genetic data coupled with simulations of stochastic environmental events can address central questions in translocation programmes.

scholarly journals Sum rules for leptons

2016 ◽  
Vol 31 (17) ◽  
pp. 1630021 ◽  
Author(s):  
Martin Spinrath
Keyword(s):  
Renormalization Group ◽  
Symmetry Breaking ◽  
Wide Class ◽  
Sum Rules ◽  
The Other ◽  
Neutrino Masses ◽  
Mixing Angles ◽  
The One ◽  
Dynamical Description ◽  
The Impact

There is a wide class of models which give a dynamical description of the origin of flavor in terms of spontaneous symmetry breaking of an underlying symmetry. Many of these models exhibit sum rules which relate on the one hand mixing angles and the Dirac CP phase with each other and/or on the other hand neutrino masses and Majorana phases with each other. We will briefly sketch how this happens and discuss briefly the impact of renormalization group corrections to the mass sum rules.

Particle capture into the lung made simple?

2011 ◽  
Vol 110 (6) ◽  
pp. 1664-1673 ◽  
Author(s):  
Talita Felipe de Vasconcelos ◽  
Bernard Sapoval ◽  
José S. Andrade ◽  
James B. Grotberg ◽  
Yingying Hu ◽  
...  
Keyword(s):  
Particle Deposition ◽  
Atmospheric Pollutants ◽  
Aerosol Therapy ◽  
Particle Capture ◽  
Complex Interplay ◽  
Quiet Breathing ◽  
Lung Structure ◽  
Entire Lung ◽  
Escape Process ◽  
The Impact

Understanding the impact distribution of particles entering the human respiratory system is of primary importance as it concerns not only atmospheric pollutants or dusts of various kinds but also the efficiency of aerosol therapy and drug delivery. To model this process, current approaches consist of increasingly complex computations of the aerodynamics and particle capture phenomena, performed in geometries trying to mimic lungs in a more and more realistic manner for as many airway generations as possible. Their capture results from the complex interplay between the details of the aerodynamic streamlines and the particle drag mechanics in the resulting flow. In contrast, the present work proposes a major simplification valid for most airway generations at quiet breathing. Within this context, focusing on particle escape rather than capture reveals a simpler structure in the entire process. When gravity can be neglected, we show by computing the escape rates in various model geometries that, although still complicated, the escape process can be depicted as a multiplicative escape cascade in which each elementary step is associated with a single bifurcation. As a net result, understanding of the particle capture may not require computing particle deposition in the entire lung structure but can be abbreviated in some regions using our simpler approach of successive computations in single realistic bifurcations. Introducing gravity back into our model, we show that this multiplicative model can still be successfully applied on up to nine generations, depending on particle type and breathing conditions.

scholarly journals How to Change the Weight of Rare Events in Decisions From Experience

2019 ◽  
Vol 30 (12) ◽  
pp. 1767-1779
Author(s):  
Jared M. Hotaling ◽  
Andreas Jarvstad ◽  
Chris Donkin ◽  
Ben R. Newell
Keyword(s):  
Decision Making ◽  
Rare Events ◽  
Standard Condition ◽  
Cumulative Prospect Theory ◽  
Parameter Estimates ◽  
Cognitive Architectures ◽  
Value Integration ◽  
Bayesian Implementation ◽  
Probability Information ◽  
The Impact

When people make risky choices, two kinds of information are crucial: outcome values and outcome probabilities. Here, we demonstrate that the juncture at which value and probability information is provided has a fundamental effect on choice. Across four experiments involving 489 participants, we compared two decision-making scenarios: one in which value information was revealed during sampling ( standard) and one in which value information was revealed after sampling ( value ignorance). On average, participants made riskier choices when value information was provided after sampling. Moreover, parameter estimates from a hierarchical Bayesian implementation of cumulative-prospect theory suggested that participants overweighted rare events when value information was absent during sampling but did not overweight such events in the standard condition. This suggests that the impact of rare events on choice relies crucially on the timing of probability and value integration. We provide paths toward mechanistic explanations of our results based on frameworks that assume different underlying cognitive architectures.

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