scholarly journals Efficient mate finding in planktonic copepods swimming in turbulence

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
François-Gaël Michalec ◽  
Itzhak Fouxon ◽  
Sami Souissi ◽  
Markus Holzner
Keyword(s):  
Time Frame ◽  
Collision Kernel ◽  
Coupling Mechanism ◽  
Calanoid Copepods ◽  
Directed Motion ◽  
Mate Finding ◽  
Ambient Flow ◽  
Turbulent Environments ◽  
Preferential Concentration ◽  
Short Time

Zooplankton live in dynamic environments where turbulence may challenge their limited swimming abilities. How this interferes with fundamental behavioral processes remains elusive. We reconstruct simultaneously the trajectories of flow tracers and calanoid copepods and we quantify their ability to find mates when ambient flow imposes physical constrains on their motion and impairs their olfactory orientation. We show that copepods achieve high encounter rates in turbulence due to the contribution of advection and vigorous swimming. Males further convert encounters within the perception radius to contacts and then to mating via directed motion toward nearby organisms within the short time frame of the encounter. Inertial effects do not result in preferential concentration, reducing the geometric collision kernel to the clearance rate, which we model accurately by superposing turbulent velocity and organism motion. This behavioral and physical coupling mechanism may account for the ability of copepods to reproduce in turbulent environments.

scholarly journals Polyethylene Migration from Food Packaging on Cheese Detected by Raman and Infrared (ATR/FT-IR) Spectroscopy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3872
Author(s):  
Klytaimnistra Katsara ◽  
George Kenanakis ◽  
Zacharias Viskadourakis ◽  
Vassilis M. Papadakis
Keyword(s):  
Vibrational Spectroscopy ◽  
Food Packaging ◽  
Time Frame ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Ft Ir ◽  
Comparative Results ◽  
Short Time ◽  
And Storage ◽  
Ft Ir Spectroscopy

For multiple years, food packaging migration has been a major concern in food and health sciences. Plastics, such as polyethylene, are continuously utilized in food packaging for preservation and easy handling purposes during transportation and storage. In this work, three types of cheese, Edam, Kefalotyri and Parmesan, of different hardness were studied under two complementary vibrational spectroscopy methods, ATR-FTIR and Raman spectroscopy, to determine the migration of low-density polyethylene from plastic packaging to the surface of cheese samples. The experimental duration of this study was set to 28 days due to the degradation time of the selected cheese samples, which is clearly visible after 1 month in refrigerated conditions at 4 °C. Raman and ATR-FTIR measurements were performed at a 4–3–4–3 day pattern to obtain comparative results. Initially, consistency/repeatability measurement tests were performed on Day0 for each sample of all cheese specimens to understand if there is any overlap between the characteristic Raman and ATR-FTIR peaks of the cheese with the ones from the low-density polyethylene package. We provide evidence that on Day14, peaks of low-density polyethylene appeared due to polymeric migration in all three cheese types we tested. In all cheese samples, microbial outgrowth started to develop after Day21, as observed visually and under the bright-field microscope, causing peak reverse. Food packaging migration was validated using two different approaches of vibrational spectroscopy (Raman and FT-IR), revealing that cheese needs to be consumed within a short time frame in refrigerated conditions at 4 °C.

scholarly journals Breeding Strategies to Improve Miscanthus as a Sustainable Source of Biomass for Bioenergy and Biorenewable Products

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 673 ◽  
Author(s):  
John Clifton-Brown ◽  
Kai-Uwe Schwarz ◽  
Danny Awty-Carroll ◽  
Antonella Iurato ◽  
Heike Meyer ◽  
...  
Keyword(s):  
Significant Contribution ◽  
Perennial Grass ◽  
Time Frame ◽  
Eastern Asia ◽  
Germplasm Collections ◽  
Naturally Occurring ◽  
Wide Range ◽  
Yield Quality ◽  
Short Time ◽  
Commercial Expansion

Miscanthus, a C4 perennial grass native to Eastern Asia, is being bred to provide biomass for bioenergy and biorenewable products. Commercial expansion with the clonal hybrid M. × giganteus is limited by low multiplication rates, high establishment costs and drought sensitivity. These limitations can be overcome by breeding more resilient Miscanthus hybrids propagated by seed. Naturally occurring fast growing indigenous Miscanthus species are found in diverse environments across Eastern Asia. The natural diversity provides for plant breeders, the genetic resources to improve yield, quality, and resilience for a wide range of climates and adverse abiotic stresses. The challenge for Miscanthus breeding is to harness the diversity through selections of outstanding wild types, parents, and progenies over a short time frame to deploy hybrids that make a significant contribution to a world less dependent on fossil resources. Here are described the strategies taken by the Miscanthus breeding programme at Aberystwyth, UK and its partners. The programme built up one of the largest Miscanthus germplasm collections outside Asia. We describe the initial strategies to exploit the available genetic diversity to develop varieties. We illustrate the success of combining diverse Miscanthus germplasm and the selection criteria applied across different environments to identify promising hybrids and to develop these into commercial varieties. We discuss the potential for molecular selections to streamline the breeding process.

Ranking the explanatory power of factors associated with worldwide new Covid-19 cases

2021 ◽  
Author(s):  
Aristides Moustakas
Keyword(s):  
Explanatory Power ◽  
Interdisciplinary Approach ◽  
Time Frame ◽  
Variance Partitioning ◽  
Total Variance ◽  
Disease Spread ◽  
Spatial Spread ◽  
Global Pandemic ◽  
Governmental Intervention ◽  
Short Time

Abstract Disease spread is a complex phenomenon requiring an interdisciplinary approach. Covid-19 exhibited a global spatial spread in a very short time frame resulting in a global pandemic. Data of new Covid-19 cases per million were analysed worldwide at the spatial scale of a country and time replicated from the end of December 2019 to late May 2020. Data driven analysis of epidemiological, economic, public health, and governmental intervention variables was performed in order to select the optimal variables in explaining new Covid-19 cases across all countries in time. Sequentially, hierarchical variance partitioning of the optimal variables was performed in order to quantify the independent contribution of each variable in the total variance of new Covid-19 cases per million. Results indicated that from the variables available new tests per thousand explained the vast majority of the total variance in new cases (51.6%) followed by the governmental stringency index (15.2%). Availability of hospital beds per 100k inhabitants explained 9% extreme poverty explained 8.8%, hand washing facilities 5.3%, the fraction of the population aged 65 or older explained 3.9%, and other disease prevalence (cardiovascular diseases plus diabetes) explained 2.9%. The percentage of smokers within the population explained 2.6% of the total variance, while population density explained 0.6%.

Crossword Puzzles: Active Learning in Undergraduate Pathology and Medical Education

2009 ◽  
Vol 133 (9) ◽  
pp. 1457-1462
Author(s):  
Anurag Saxena ◽  
Raenelle Nesbitt ◽  
Punam Pahwa ◽  
Sheryl Mills
Keyword(s):  
Student Perceptions ◽  
Small Groups ◽  
Time Frame ◽  
Teaching Tool ◽  
Internet Resource ◽  
Cooperative Groups ◽  
Key Concepts ◽  
Second Year ◽  
Peer Teachers ◽  
Short Time

Abstract Context.—Second-year medical students are introduced to many new terms and concepts in a short time frame in the hematology system and the neoplasia section of the undergraduate pathology course. It is a challenge to provide adequate practice and necessary repetition to reinforce key concepts. Objective.—To determine student perceptions of the usefulness of crosswords as a quick and effective way to reinforce essential concepts and vocabulary. Design.—Crosswords with ensured content validity built on a free Internet resource were completed by the students in collaborative and cooperative groups of 6 to 7 with a reward for the first group to successfully complete the puzzle. Student perceptions of the value of crosswords for their learning were examined in 2003 (39 students) with a survey of yes or no responses and in 2004 (41 students) with a survey using questions with a 5-point Likert scale. Results.—Many students (37 of 39 in 2003 and 24 of 41 in 2004) indicated that crosswords were useful and contributed to their learning. Specifically, crosswords were found to be useful for identifying key concepts and vocabulary and for their collaborative and competitive aspects. Written and informal comments indicated student enthusiasm for and a desire to participate in more of these exercises. Students have transferred this review strategy to other classes and the peer teachers have expressed an interest in it as an adjunct teaching tool. Conclusions.—The judicious use of crosswords was useful for near transfer content and provided an opportunity to discuss and recall essential concepts, think critically, and collaborate in small groups.

scholarly journals Case study: use of Rapid Ethnographic research for participatory urban design

2020 ◽  
Keyword(s):  
Urban Design ◽  
Time Frame ◽  
Assessment Process ◽  
Ethnographic Research ◽  
City Center ◽  
Design Practices ◽  
Short Time ◽  
Historic City ◽  
Ways Of Life

This article analyzed the use of rapid ethnographic methodologies to assess community concerns for urban design practices. Rapid Ethnographic Assessment Process (REAP) is a compilation of methodologies that produce ethnographic knowledge in a short time frame and is constantly used for public health and sustainability. The article is about a participatory case-study conducted in the historic city center of Santiago de Los Caballeros, in the Dominican Republic. REAP was used to understand its application for urbanism. The case-study revealed a spectrum of cultures from different groups within the study area, and how the project would impact their ways of life. It also depicted a gap between the pre-existing proposals and the aims and challenges of the community groups. If appropriately applied, REAP can produce valuable results, and help inform urban design practices while assuring that they are respectful to the populations they will influence.

scholarly journals TOWARDS A MORE EFFICIENT DETECTION OF EARTHQUAKE INDUCED FAÇADE DAMAGES USING OBLIQUE UAV IMAGERY

2017 ◽  
Vol XLII-2/W6 ◽  
pp. 93-100 ◽  
Author(s):  
D. Duarte ◽  
F. Nex ◽  
N. Kerle ◽  
G. Vosselman
Keyword(s):  
Damage Detection ◽  
Time Frame ◽  
Image Features ◽  
Search And Rescue ◽  
Urban Search And Rescue ◽  
Damage Classification ◽  
Efficient Detection ◽  
Oblique Images ◽  
Short Time ◽  
The City

Urban search and rescue (USaR) teams require a fast and thorough building damage assessment, to focus their rescue efforts accordingly. Unmanned aerial vehicles (UAV) are able to capture relevant data in a short time frame and survey otherwise inaccessible areas after a disaster, and have thus been identified as useful when coupled with RGB cameras for façade damage detection. Existing literature focuses on the extraction of 3D and/or image features as cues for damage. However, little attention has been given to the efficiency of the proposed methods which hinders its use in an urban search and rescue context. The framework proposed in this paper aims at a more efficient façade damage detection using UAV multi-view imagery. This was achieved directing all damage classification computations only to the image regions containing the façades, hence discarding the irrelevant areas of the acquired images and consequently reducing the time needed for such task. To accomplish this, a three-step approach is proposed: i) building extraction from the sparse point cloud computed from the nadir images collected in an initial flight; ii) use of the latter as proxy for façade location in the oblique images captured in subsequent flights, and iii) selection of the façade image regions to be fed to a damage classification routine. The results show that the proposed framework successfully reduces the extracted façade image regions to be assessed for damage 6 fold, hence increasing the efficiency of subsequent damage detection routines. The framework was tested on a set of UAV multi-view images over a neighborhood of the city of L’Aquila, Italy, affected in 2009 by an earthquake.

scholarly journals LIMITATIONS OF THE PANEL REGRESSION MODEL APPLICATION: THE EXAMPLE OF THE WESTERN BALKAN COUNTRIES

2021 ◽  
Vol 18 (32) ◽  
Author(s):  
Stanko Stanić ◽  
Bojan Baškot
Keyword(s):  
Time Series ◽  
Regression Model ◽  
Time Frame ◽  
Panel Regression ◽  
Time Dimension ◽  
Data Set ◽  
Short Time Series ◽  
Western Balkan Region ◽  
Balkan Region ◽  
Short Time

Panel regression model may seem like an appealing solution in conditions of limited time series. This is often used as a shortcut to achieve deeper data set by setting several individual cases on the same time dimension, where cross units visually but not really multiply a time frame. Macroeconometrics of the Western Balkan region assumes short time series issue. Additionally, the structural brakes are numerous. Panel regression may seem like a solution, but there are some limitations that should be considered.

scholarly journals Continuous Viral Escape and Selection by Autologous Neutralizing Antibodies in Drug-Naïve Human Immunodeficiency Virus Controllers

2008 ◽  
Vol 83 (2) ◽  
pp. 662-672 ◽  
Author(s):  
Madhumita Mahalanabis ◽  
Pushpa Jayaraman ◽  
Toshiyuki Miura ◽  
Florencia Pereyra ◽  
E. Michael Chester ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Neutralizing Antibodies ◽  
Time Frame ◽  
Continuous Selection ◽  
Viral Escape ◽  
Elite Controllers ◽  
Hiv Replication ◽  
Immunodeficiency Virus ◽  
Short Time

ABSTRACT We assessed differences in the character and specificity of autologous neutralizing antibodies (ANAbs) against individual viral variants of the quasispecies in a cohort of drug-naïve subjects with long-term controlled human immunodeficiency virus type 1 (HIV-1) infection and moderate levels of broad heterologous neutralizing antibodies (HNAb). Functional plasma virus showed continuous env evolution despite a short time frame and low levels of viral replication. Neutralization-sensitive variants dominated in subjects with intermittent viral blips, while neutralization-resistant variants predominated in elite controllers. By sequence analysis of this panel of autologous variants with various sensitivities to neutralization, we identified more than 30 residues in envelope proteins (Env) associated with resistance or sensitivity to ANAbs. The appearance of new sensitive variants is consistent with a model of continuous selection and turnover. Strong ANAb responses directed against autologous Env variants are present in long-term chronically infected individuals, suggesting a role for these responses in contributing to the durable control of HIV replication.

Transitioning Courses During COVID-19

2021 ◽  
pp. 99-125
Author(s):  
Kanita K. DuCloux ◽  
Michelle S. Jones ◽  
Jeffrey D. Herron
Keyword(s):  
College Students ◽  
Predominantly White ◽  
Time Frame ◽  
Colleges And Universities ◽  
Predominantly White Institutions ◽  
Black Faculty ◽  
Face To Face ◽  
White Institutions ◽  
Face To Face Instruction ◽  
Short Time

In this chapter, three Black faculty from two different predominantly white institutions (PWIs) reflect on how they were able to successfully transition their traditional face-to-face courses to online or remote courses in a short time frame. They briefly describe the two institutions followed by a discussion of the struggles with technological issues, the benefits and disadvantages of working from home, as well as the stress of coping with COVID-19-related issues. Next, the faculty describe the strategies implemented with college students to help the students navigate the transition and be successful in their courses when all schools, colleges, and universities were forced to make the switch from traditional face-to-face instruction to online or remote teaching due to the pandemic.

scholarly journals Massive computational acceleration by using neural networks to emulate mechanism-based biological models

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Shangying Wang ◽  
Kai Fan ◽  
Nan Luo ◽  
Yangxiaolu Cao ◽  
Feilun Wu ◽  
...  
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Mechanistic Model ◽  
Time Frame ◽  
Biological Applications ◽  
Biological Models ◽  
Parametric Space ◽  
Trained Neural Network ◽  
Short Time

Abstract For many biological applications, exploration of the massive parametric space of a mechanism-based model can impose a prohibitive computational demand. To overcome this limitation, we present a framework to improve computational efficiency by orders of magnitude. The key concept is to train a neural network using a limited number of simulations generated by a mechanistic model. This number is small enough such that the simulations can be completed in a short time frame but large enough to enable reliable training. The trained neural network can then be used to explore a much larger parametric space. We demonstrate this notion by training neural networks to predict pattern formation and stochastic gene expression. We further demonstrate that using an ensemble of neural networks enables the self-contained evaluation of the quality of each prediction. Our work can be a platform for fast parametric space screening of biological models with user defined objectives.

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