scholarly journals Family variation in surface feeding behavior of steelhead fry predicts growth rate under hatchery conditions

2020 ◽  
Author(s):  
Madeleine C. Wrey ◽  
James C. Skaar ◽  
Stanley B. Cates ◽  
Stephanie R. Bollmann ◽  
Claudio Fuentes ◽  
...  
Keyword(s):  
Growth Rate ◽  
Initial Growth ◽  
The Novel ◽  
Steelhead Trout ◽  
Rapid Adaptation ◽  
Substantial Variation ◽  
Natural Origin ◽  
Full Sibling ◽  
In The Wild ◽  
Adaptation To Captivity

AbstractHatchery reared salmonid fish often have lower fitness than their natural-origin counterparts when spawning in the wild. Although this difference appears to result from rapid adaptation to captivity, it is not known what traits are under selection. We hypothesize that variation in traits that confer a growth rate advantage to some individuals in the novel hatchery environment are under strong selection because survival at sea is correlated with size at release. Here we show that full sibling families of steelhead trout (Oncorhynchus mykiss) show substantial variation in propensity to feed at the surface as fry, and that the more surface-oriented families grew faster under hatchery conditions. We hypothesize that surface-oriented fry gain an initial growth advantage that persists through size at release. Because surface orientation is a correlate of generalized boldness, hatcheries may inadvertently select for that phenotype, which could explain the fitness differences observed between hatchery and natural-origin fish in the wild.

Abstract 180: The Growth Rate of Early DWI Lesions is Highly Variable and Associated with Penumbral Salvage and Clinical Outcomes Following Endovascular Reperfusion

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Hayley M Wheeler ◽  
Michael Mlynash ◽  
Manabu Inoue ◽  
Aaryani Tipirneni ◽  
John Liggins ◽  
...  
Keyword(s):  
Growth Rate ◽  
Acute Stroke ◽  
Clinical Outcomes ◽  
Endovascular Therapy ◽  
Symptom Onset ◽  
Growth Rates ◽  
Initial Growth ◽  
Stroke Patients ◽  
Final Volume ◽  
Favorable Clinical Response

Background: The degree of variability in the rate of early DWI expansion has not been well characterized. We hypothesized that Target Mismatch patients with slowly expanding DWI lesions have more penumbral salvage and better clinical outcomes following endovascular reperfusion than Target Mismatch patients with rapidly expanding DWI lesions. Methods: This substudy of DEFUSE 2 included all patients with a clearly established time of symptom onset. The initial DWI growth rate was determined from the baseline scan by assuming a volume 0 ml just prior to symptom onset. Target Mismatch patients who achieved reperfusion (>50% reduction in PWI after endovascular therapy), were categorized into tertiles according to their initial DWI growth rates. For each tertile, penumbral salvage (comparison of final volume to the volume of PWI (Tmax > 6 sec)/ DWI mismatch prior to endovascular therapy), favorable clinical response, and good functional outcome (see figure for definitions) were calculated. We also compared the growth rate in patients with the Target mismatch vs. Malignant Profile. Results: 64 patients were eligible for this study. Target mismatch patients (n=44) had initial growth rates (range 0 to 43 ml/hr, median of 3 ml/hr) that were significantly less than the growth rates in Malignant profile (n=7) patients (12 to 92 ml/hr, median 39 ml/hr; p < 0.001). In Target mismatch patients who achieved reperfusion (n=30), slower early DWI growth rates were associated with better clinical outcomes (p<0.05) and a trend toward more penumbral salvage (n=27, p=0.137). Conclusions: The growth rate of early DWI lesions in acute stroke patients is highly variable; Malignant profile patients have higher growth rates than other MRI profiles. Among Target Mismatch patients, a slower rate of DWI growth is associated with a greater degree of penumbral salvage and improved clinical outcomes following endovascular reperfusion.

scholarly journals A Spatio-Temporal Investigation of the Growth Rate of COVID-19 Incidents in Ohio, USA, Early in the Pandemic

2021 ◽  
Vol 121 (2) ◽  
pp. 33-47
Author(s):  
Alessandro M. Selvitella ◽  
Liam Carolan ◽  
Justin Smethers ◽  
Christopher Hernandez ◽  
Kathleen L. Foster
Keyword(s):  
Growth Rate ◽  
Transmission Rate ◽  
Time Lag ◽  
Early Period ◽  
Mitigation Strategies ◽  
Initial Growth ◽  
School Closures ◽  
Policy Makers ◽  
Susceptible Population ◽  
Spatio Temporal

Understanding the initial growth rate of an epidemic is important for epidemiologists and policy makers as it can impact their mitigation strategies such as school closures, quarantines, or social distancing. Because the transmission rate depends on the contact rate of the susceptible population with infected individuals, similar growth rates might be experienced in nearby geographical areas. This research determined the growth rate of cases and deaths associated with COVID-19 in the early period of the 2020 pandemic in Ohio, United States. The evolution of cases and deaths was modeled through a Besag-York-Molliè model with linear- and power-type deterministic time dependence. The analysis showed that the growth rate of the time component of the model was subexponential in both cases and deaths once the time-lag across counties of the appearance of the first COVID-19 case was considered. Moreover, deaths in the northeast counties in Ohio were strongly related to the deaths in nearby counties.

The Richtmyer–Meshkov instability of a ‘V’ shaped air/ interface

2016 ◽  
Vol 802 ◽  
pp. 186-202 ◽  
Author(s):  
Xisheng Luo ◽  
Ping Dong ◽  
Ting Si ◽  
Zhigang Zhai
Keyword(s):  
Growth Rate ◽  
High Speed ◽  
Initial Conditions ◽  
Monotone Function ◽  
Flow Characteristics ◽  
Soap Film ◽  
Vertex Angle ◽  
Initial Growth ◽  
General Behaviour ◽  
Interface Width

The Richtmyer–Meshkov instability on a ‘V’ shaped air/SF$_{6}$ gaseous interface is experimentally studied in a shock tube. By the soap film technique, a discontinuous interface without supporting mesh is formed so that the initial conditions of the interface can be accurately controlled. Five ‘V’ shaped air/$\text{SF}_{6}$ interfaces with different vertex angles ($60^{\circ }$, $90^{\circ }$, $120^{\circ }$, $140^{\circ }$ and $160^{\circ }$) are created where the ratio of the initial interface amplitude to the wavelength varies to highlight the effects of initial condition on the flow characteristics. The wave patterns and interface morphologies are clearly identified in the high-speed schlieren sequences, which show that the interface deforms in a less pronounced manner with less vortices generated as the vertex angle increases. A regime change is observed in the interface width growth rate near a vertex angle of $160^{\circ }$, which provides an experimental evidence for the numerical results obtained by McFarland et al. (Phys. Scr. vol. T155, 2013, 014014). The growth rate of interface width in the linear phase is compared with the theoretical predictions from the classical impulsive model and a modified linear model, and the latter is proven to be effective for a moderate to large initial amplitude. It is found that the initial growth rate of the interface width is a non-monotone function of the initial vertex angle (amplitude–wavelength ratio), i.e. the interface width growth rate in the linear stage experiences an increase and then a decrease as the vertex angle increases. A similar conclusion was also reached by Dell et al. (Phys. Plasmas, vol. 22, 2015, 092711) numerically for a sinusoidal interface. Finally, the general behaviour of the interface width growth in the nonlinear stage can be well captured by the nonlinear model proposed by Dimonte & Ramaprabhu (Phys. Fluids, vol. 22, 2010, 014104).

scholarly journals An Endophytic Trichoderma Strain Promotes Growth of Its Hosts and Defends Against Pathogen Attack

2020 ◽  
Vol 11 ◽  
Author(s):  
Yu-Heng Tseng ◽  
Hamid Rouina ◽  
Karin Groten ◽  
Pijakala Rajani ◽  
Alexandra C. U. Furch ◽  
...  
Keyword(s):  
Pathogenic Fungus ◽  
Alternaria Brassicicola ◽  
Plant Performance ◽  
Nicotiana Attenuata ◽  
Initial Growth ◽  
The Novel ◽  
Leucas Aspera ◽  
Deciduous Wood ◽  
Agricultural Applications ◽  
Multilocus Phylogeny

Plants host numerous endophytic microbes which promote plant performance, in particular under stress. A new endophytic fungus was isolated from the leaves of a deciduous wood tree Leucas aspera. Morphological inspection and multilocus phylogeny identified the fungus as a new Trichoderma strain. If applied to Arabidopsis thaliana and Nicotiana attenuata, it mainly colonizes their roots and strongly promotes initial growth of the plants on soil. The fungus grows on high NaCl or mannitol concentrations, and shows predatory capability on the pathogenic fungus Alternaria brassicicola. Colonized Arabidopsis plants tolerate higher salt stress and show lower A. brassicicola spread in roots and shoots, while arbuscular mycorrhiza formation in N. attenuata is not affected by the Trichoderma strain. These beneficial features of the novel Trichoderma strain are important prerequisites for agricultural applications.

Within-river straying: sex and size influence recovery location of hatchery Chinook salmon (Oncorhynchus tshawytscha)

2020 ◽  
Vol 77 (2) ◽  
pp. 226-235 ◽  
Author(s):  
Amanda M.M. Pollock ◽  
Maryam Kamran ◽  
Andrew H. Dittman ◽  
Marc A. Johnson ◽  
David L.G. Noakes
Keyword(s):  
River Basin ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Classification Tree ◽  
River System ◽  
Classification Tree Analysis ◽  
Spawning Grounds ◽  
Natural Origin ◽  
Elk River ◽  
In The Wild

Salmon straying is often defined as the failure of adults to return to their natal river system. However, straying within a river basin can be problematic if hatchery salmon do not return to their hatchery of origin and subsequently spawn in the wild with natural-origin salmon. We examined within-river straying patterns from 34 years of coded-wire tag data, representing 29 941 hatchery fall Chinook salmon (Oncorhynchus tshawytscha) in the Elk River, Oregon, USA. Using classification tree analysis, we found that females and larger salmon were more likely to be recovered on the spawning grounds than males and smaller fish. Females larger than 980 mm had a 51.6% likelihood of recovery on the spawning grounds rather than at the Elk River Hatchery. Our findings raise questions about the behavior of straying adults and implications for management of these stocks, with a focus on methods to reduce within-river straying. We recommend further studies to determine whether carcass recoveries are fully representative of hatchery salmon that stray within the Elk River basin.

scholarly journals Plasmid DNA Production in Proteome-Reduced Escherichia coli

2020 ◽  
Vol 8 (9) ◽  
pp. 1444
Author(s):  
Mitzi de la Cruz ◽  
Elisa A. Ramírez ◽  
Juan-Carlos Sigala ◽  
José Utrilla ◽  
Alvaro R. Lara
Keyword(s):  
Escherichia Coli ◽  
Plasmid Dna ◽  
Type Strain ◽  
Wild Type Strain ◽  
The Novel ◽  
Wild Type ◽  
Batch Mode ◽  
Cell Factories ◽  
Starting Point ◽  
In The Wild

The design of optimal cell factories requires engineering resource allocation for maximizing product synthesis. A recently developed method to maximize the saving in cell resources released 0.5% of the proteome of Escherichia coli by deleting only three transcription factors. We assessed the capacity for plasmid DNA (pDNA) production in the proteome-reduced strain in a mineral medium, lysogeny, and terrific broths. In all three cases, the pDNA yield from biomass was between 33 and 53% higher in the proteome-reduced than in its wild type strain. When cultured in fed-batch mode in shake-flask, the proteome-reduced strain produced 74.8 mg L−1 pDNA, which was four times greater than its wild-type strain. Nevertheless, the pDNA supercoiled fraction was less than 60% in all cases. Deletion of recA increased the pDNA yields in the wild type, but not in the proteome-reduced strain. Furthermore, recA mutants produced a higher fraction of supercoiled pDNA, compared to their parents. These results show that the novel proteome reduction approach is a promising starting point for the design of improved pDNA production hosts.

An Investigation Into Nonlinear Growth Rate of Two-Dimensional and Three-Dimensional Single-Mode Richtmyer–Meshkov Instability Using an Arbitrary-Lagrangian–Eulerian Algorithm

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Mike Probyn ◽  
Ben Thornber ◽  
Dimitris Drikakis ◽  
David Youngs ◽  
Robin Williams
Keyword(s):  
Growth Rate ◽  
Numerical Scheme ◽  
Initial Conditions ◽  
Numerical Study ◽  
Three Dimensional ◽  
Single Mode ◽  
Computational Time ◽  
Initial Growth ◽  
Arbitrary Lagrangian Eulerian ◽  
Layer Width

This paper presents an investigation into the use of a moving mesh algorithm for solving unsteady turbulent mixing problems. The growth of a shock induced mixing zone following reshock, using an initial setup comparable to that of existing experimental work, is used to evaluate the behavior of the numerical scheme for single-mode Richtmyer–Meshkov instability (SM-RMI). Subsequently the code is used to evaluate the growth rate for a range of different initial conditions. The initial growth rate for three-dimensional (3D) SM Richtmyer–Meshkov is also presented for a number of different initial conditions. This numerical study details the development of the mixing layer width both prior to and after reshock. The numerical scheme used includes an arbitrary Lagrangian–Eulerian grid motion which is successfully used to reduce the mesh size and computational time while retaining the accuracy of the simulation results. Varying initial conditions shows that the growth rate after reshock is independent of the initial conditions for a SM provided that the initial growth remains in the linear regime.

scholarly journals Competition between related strains of nodule bacteria and its influence on infection of the legume host

1941 ◽  
Vol 130 (858) ◽  
pp. 32-59 ◽  
Keyword(s):  
Growth Rate ◽  
Nitrogen Fixation ◽  
Root System ◽  
Short Duration ◽  
Pure Culture ◽  
The Other ◽  
Initial Growth ◽  
Nodule Bacteria ◽  
Long Period ◽  
Different Strains

The work deals with the behaviour of mixed strains of nodule bacteria towards each other and towards their legume host. It introduces the concept of dominance in competition between strains. This dominance is independent of degree of effectiveness as regards nitrogen fixation. Where tow strains of nodule bacteria are both present in the surroundings of their host's root system, active competition between them may cause the strain having the higher initial growth rate almost completely to check multiplication of the other strain outside the plant. This dominant strain will then be responsible for nearly all the nodules. In peas and soy beans, where growth of the root sysytem is rapid and of comparatively short duration, the nodule-producing capacity of the plant may be partially or wholly satisfied by the nodules produced within the first few weeks, so that further infection, whether by the same or by a different strain, is checked or inhibited. In clover, whose root system continues to grow over a long period, the first-formed nodules do not stop further nodules from being formed either by the same or by a different strain. There are large differences in the rates of appearance and final numbers of nodules produced by different strains supplied in pure culture, particularly with clover. The relative numbers of nodules produced by the two strains simultaneously applied to the roots is conditioned by the specific infectivity peculiar to each strain, unless some other factor, such as competition outside the plant, masks this effect.

The growth of apricot fruit. II. The effects of temperature and gibberellic acid

1967 ◽  
Vol 18 (1) ◽  
pp. 95 ◽  
Author(s):  
DI Jackson ◽  
BG Coombe
Keyword(s):  
Growth Rate ◽  
Cell Division ◽  
Gibberellic Acid ◽  
Fruit Size ◽  
Fruit Growth ◽  
Cell Diameter ◽  
Initial Growth ◽  
Endogenous Gibberellin ◽  
Flower Buds ◽  
Size And Shape

The effect of temperature and gibberellic acid (GA3) applications on apricot fruit have been determined by measurements of fruit size and shape, mesocarp cell number, size, and shape, and endogenous gibberellin. Application of heat during the first 10 nights after anthesis increased the initial growth rate of fruit and of cells in the mesocarp and produced more rapid cell division in this tissue. It did not affect final fruit size or the number and diameter of cells in the mesocarp. Higher temperatures did, however, hasten maturity of fruit. GA3 perfused into branches before anthesis produced an increased drop of flower buds and fruit, raised the ratio of flower buds to leaf buds initiated that season, and resulted in elongated pedicels. Initially, fruit growth rate was increased by GA3, but subsequently it was depressed and final size was below normal. These effects on fruit size were mainly due to effects on the rate of cell division. Some differences were noted in the dimensions of cells but final radial cell diameter did not differ from untreated fruit. GA3-treated fruit ripened sooner than controls. Neither heating nor GA3 treatments affected the level of endogenous gibberellin-like substances in the fruit or their RF on paper chromatograms. There were no significant interactions between temperature and gibberellin in any parameter of apricot fruit growth.

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