Use of spectral analysis to estimate short-term periodicities in growth rates of brook trout Salvelinus frontinalis

1997 ◽  
Vol 54 (7) ◽  
pp. 1532-1541 ◽  
Author(s):  
W Aboul Hosn ◽  
P Dutilleul ◽  
D Boisclair
Keyword(s):  
Growth Rate ◽  
Spectral Analysis ◽  
Growth Rates ◽  
Repeated Measures ◽  
Brook Trout ◽  
Short Term ◽  
Experimental Conditions ◽  
Relative Growth Rates ◽  
Repeated Measures Design ◽  
Periodic Components

We used spectral analysis to investigate the periodic components of relative growth rates (on a mass and length basis) in two groups of six\b young-of-the-year brook trout (Salvelinus fontinalis). Fish were measured every 2 days for 25 days according to a repeated measures design in time. The predominant frequency components were estimated at the end of a stepwise procedure involving the analysis of the multifrequential periodogram. We found mainly two superimposed periodic components that resulted in short rhythms; these had a period of about 5 and 10 days for the growth rate in mass and of about 4 and 6 days for the growth rate in length (R2 = 91% for mass and 90% for length, both including an autocorrelation term). Repeatability of rhythms was assessed by ANOVA of the finite Fourier transform, which showed that the two groups of fish reared under the same experimental conditions exhibited growth rhythms that were not significantly different from each other. On that basis, we present a harmonic model which predicts short-term variation in growth rate of brook trout in mass (R2pred = 0.73, with an autocorrelation term) and in length (R2pred = 0.72).

The Relative Growth of Parts in Palaemon Carcinus

1930 ◽  
Vol 7 (2) ◽  
pp. 165-174
Author(s):  
M. A. TAZELAAR
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Linear Measurements ◽  
Relative Growth ◽  
Male And Female ◽  
Relative Growth Rates ◽  
Rate Of Growth ◽  
The Difference ◽  
Rates Of Growth

Linear measurements of certain appendages and the carapace of P. carcinus were made and plotted in various ways. The following conclusions were drawn: 1. The cheliped shows heterogonic growth in both male and female, but more markedly in the male, the values of k being: male 1.8 and female 1.48 2. The pereiopods in both male and female are slightly heterogonic. The relative growth rates are graded from p3 to p5, that of p3 being slightly greater than that of p5 3. Of the ordinary pereiopods the rate of growth of p1 is the smallest in the male, but the largest in the female. 4. The difference between the rates of growth of p1 and p3 in male and female is greatest where the rate of growth in the heterogonic organ, the cheliped, is most excessive in the male. 5. The growth of the 3rd maxilliped is slightly negatively heterogonic, the value of k in the male being 0.93 and in the female 0.95. Hence there seems to be a correlation between the marked heterogony in the cheliped on the growth rate of neighbouring appendages. In those immediately posterior to the cheliped the growth rate is increased and in those anterior decreased.

Kinetics And Morphology Of Homoepitaxial Cvd Growth On Diamond (100) And (111)

1995 ◽  
Vol 416 ◽  
Author(s):  
R. E. Rawles ◽  
W. G. Morris ◽  
M. P. D’Evelyn
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Chemical Vapor ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Arrhenius Behavior ◽  
Oriented Growth ◽  
Relative Growth Rates ◽  
Cvd Growth ◽  
Hot Filament

ABSTRACTGrowth rates for homoepitaxy of diamond (100) and (111) by hot-filament chemical vapor deposition were measured via in situ Fizeau interferometry and the surface morphologies were subsequently characterized by atomic force microscopy (AFM). (100)-oriented growth from 0.5% CH4 in H2 exhibited pure Arrhenius behavior, with an activation energy of 17±1 kcal/mol, up to a substrate temperature of 1100°C. Addition of oxygen to the feed gas resulted in an increased growth rate below 900°C, a maximum growth rate between 900 and 1000°C, and etching (of diamond) above 1050 - 1100°C. However, the presence of oxygen apparently had less effect on the surface morphology than did the (100)-to-(111) growth rate parameter α, determined directly from the relative growth rates of (100) and (111) substrates mounted side by side. During homoepitaxial growth from 0.5% CH4 in H2 at 875°C of ca. 1-micron-thick films,α = was 2.2 without oxygen and 1.3 for growth with 0.14% O2. The (100) film grown with α = 2.2 was quite smooth, while that with α = 1.3 was covered by numerous hillocks and penetration twins. AFM analysis revealed surprisingly little difference between the (111) films despite the considerable difference in α. Implications of these results for the growth mechanism are discussed.

Analyzing growth in cell cultures. I. Calculating growth rates

1986 ◽  
Vol 64 (1) ◽  
pp. 233-237 ◽  
Author(s):  
Susan R. Singer
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Rate Equations ◽  
Constant Growth Rate ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Growing Cell ◽  
Absolute Growth ◽  
Plant Tissue Cultures

Growth is the major parameter used to assess novel phenotypes derived from plant tissue cultures. Any quantitative analysis of growth must have an explicit rational basis. Frequently this criterion is not met. For example, the calculation (W2 − W1)/W1(W1 = initial weight; W2 = final weight) approximates neither linear nor exponential growth. Yet, it is a common method of analysis, as is the related calculation W2/W1. When absolute growth values provide insufficient information, meaningful relative growth rate equations can be utilized. Relative growth rates should be evaluated as ln (W2/W1)/(t2 − t1) for t = time, thereby yielding a constant growth rate for exponentially growing cell lines. Linear growth (root growth, for example) can be approximated by 2(W2 − W1)/((W1 + W2)(t2 − t1)). All methods of analysis we have encountered assume that relative growth at a given instant depends on total mass. The possibility exists that growth may actually be proportional to mass raised to some power less than one. For example, growth could be limited to a thin outer shell of a spherical callus. Then the relative growth rate would equal 3(W21/3 − W11/3)/(t2 − t1). Data can be seriously distorted when inappropriate calculations are used. Such distortions are exacerbated when comparisons are made. In all cases an adequate assessment of growth kinetics for each cell line and each treatment is essential.

Relationship between growth rate and undercooling in Pt-added Y1Ba2Cu3O7−x

1996 ◽  
Vol 11 (5) ◽  
pp. 1114-1119 ◽  
Author(s):  
A. Endo ◽  
H. S. Chauhan ◽  
Y. Nakamura ◽  
Y. Shiohara
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Parabolic Equation ◽  
Growth Rates ◽  
Crystal Size ◽  
Experimental Conditions ◽  
Seed Crystals ◽  
Cooling Method ◽  
Increasing Trend ◽  
Good Agreement

Y1Ba2Cu307−x (Y123) crystals were grown by two different methods, the constant undercooling solidification and the continual cooling method, with top seeding by Sm123 seed crystals in order to investigate a relationship between undercooling (ΔT) and a growth rate (R). The crystals of Y123 with a sharp faceted interface, which consisted of {100} and {001} faces, grew epitaxially from the seed. It was found that the growth rates of {100} face (Ra) and that of {001} face (Rc) showed an increasing trend with increasing ΔT, and Rc was faster than Ra within these experimental conditions, ΔT < 20 K. The relation between R and ΔT follows the parabolic equation, viz. Ra ∝ ΔT1.9 and Rc ∝ ΔT1.3 for {100} and {001} faces, respectively. The simulated crystal size using the R and ΔT relations obtained from the constant undercooling method showed good agreement with experimental data by the continual cooling.

Response of a Brook Trout (Salvelinus fontinalis) Population to a Reduction in Stream Benthos Following an Insecticide Treatment

1990 ◽  
Vol 47 (7) ◽  
pp. 1387-1401 ◽  
Author(s):  
D. P. Kreutzweiser
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Brook Trout ◽  
Food Resource ◽  
Fish Growth ◽  
Invertebrate Drift ◽  
Age Classes ◽  
Insecticide Treatment ◽  
Forest Stream ◽  
Aquatic Food

A forest stream was treated with permethrin to determine the response of brook trout to a reduction in the aquatic food resource following an insecticide treatment. The treatment resulted in massive invertebrate drift and significant reductions of benthos, but did not produce trout mortality or evidence of unusual behaviour. The density, population age structure, movement patterns, and condition of brook trout were not measurably affected by the permethrin treatment. The growth rates of 0 + and 1 + age-classes were significantly lower following the insecticide application than those of trout from the same age-classes of pretreatment years. This reduction in growth rate resulted in significantly smaller trout after treatment. A significant reduction in the growth of trout collected during the same period from a nearby untreated control stream indicated that unusually high summer temperatures were at least partially, if not entirely, responsible for the reduced growth rate of treated fish. Growth rates returned to or exceeded pretreatment levels by the overwinter period of the treatment year.

Growth responses of six bryophyte species to different light intensities

1993 ◽  
Vol 71 (5) ◽  
pp. 661-665 ◽  
Author(s):  
Emmanuel Rincón
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Growth Rates ◽  
Growth Analysis ◽  
Total Chlorophyll ◽  
Light Conditions ◽  
Growth Responses ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Plastic Responses

The growth responses of Brachythecium rutabulum, Eurhynchium praelongum, Lophocolea bidentata, Plagiomnium undulatum, Pseudoscleropodium purum, and Thuidiurn tamariscinum, growing under seven different light conditions, were determined in a 36-day laboratory experiment. Biomass production, relative growth rate, chlorophyll content, and morphological plastic responses (bending of the shoots) were determined following initial and final harvests. All species achieved greater biomass as irradiance increased. This trend was also observed in the relative growth rates, which were higher as irradiance increased, for all the bryophytes investigated. All species except L. bidentata showed an increased elevation of the shoot as irradiance decreased. Total chlorophyll was higher in all species at the lowest irradiance level, but no clear differences were observed in the ratios of chlorophyll a to b for all the species. Key words: grassland bryophytes, light intensity, growth analysis, plasticity.

Subalpine plants show short-term positive growth responses to experimental warming and fire

2009 ◽  
Vol 57 (6) ◽  
pp. 465 ◽  
Author(s):  
Frith C. Jarrad ◽  
Carl-Henrik Wahren ◽  
Richard J. Williams ◽  
Mark A. Burgman
Keyword(s):  
Plant Growth ◽  
Climate Warming ◽  
Growth Rates ◽  
Growth Forms ◽  
Growth Responses ◽  
Short Term ◽  
Widespread Species ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Positive Growth

Climate warming has the potential to directly affect plant growth rates by accelerating plant processes, and through intermediate affects associated with increased length of the growing season and changes to soil processes. Alpine and subalpine ecosystems may be particularly vulnerable to climate warming because species are adapted to a cold environment and have limited upslope refugia in Australia. In the present study, the vegetative growth of seven subalpine open-heath species was examined in response to 3 years of warming and a wildfire. The warming experiment was established in late 2003 on the Bogong High Plains, Australia, using the protocols of the International Tundra Experiment (ITEX). During the growing seasons (snow-free periods) in 2004/2005 and 2005/2006 leaves and stems were monitored on common or widespread species from each of the major vascular plant growth forms. Plants were monitored inside and outside passively warmed open-topped chambers, at sites that were burnt in early 2003 and sites that escaped fire. In the short-term, warming had significant positive relationships with relative growth rates of three species, including Celmisia pugioniformis (forb; P = 0.09), Carex breviculmis (graminoid; P = 0.004) and Asterolasia trymalioides (shrub; P = 0.02). Burning had significant positive effects (P < 0.05) on the relative growth rates of two of these species, C. pugioniformis and C. breviculmis, as well as for Plantago euryphylla, Poa hiemata and Pimelea alpina. For P. euryphylla and P. alpina, the interaction of warming and burning showed significant relationships with relative growth rates, a negative relationship in P. euryphylla (P = 0.03) and a positive relationship in P. alpina (P = 0.07). Year and season were also found to affect the relative growth rates of most species (P < 0.05). These findings agree with previous northern hemisphere ITEX and other warming experiment results; that is, warming has a positive effect on species’ growth responses. In the present study, it is likely that continued climate warming may result in positive growth responses in other subalpine species across growth forms. Our findings emphasise the value of examining multiple species in climate-change studies.

Effectiveness of a Workshop Intervention on Responsible Reporting on Suicide Among Swiss Media Professionals

Crisis ◽  
2019 ◽  
Vol 40 (6) ◽  
pp. 446-450 ◽  
Author(s):  
Sebastian Scherr ◽  
Antonia Markiewitz ◽  
Florian Arendt
Keyword(s):  
Repeated Measures ◽  
Attitudes And Beliefs ◽  
Unintended Effects ◽  
Short Term ◽  
Perceived Knowledge ◽  
Limited Knowledge ◽  
Positive Effects ◽  
Repeated Measures Design ◽  
Media Professionals ◽  
Workshop Intervention

Abstract. Objective: There is limited knowledge about the effects of a workshop intervention on responsible reporting on suicide (RRS) by media professionals. The study aimed to test how a workshop can shape reporting-relevant attitudes and beliefs among media professionals. Method: A pre–postintervention survey of Swiss media professionals ( N = 26, 55.7% male, Mage = 38.1, SDage = 12.8, all Swiss nationals) was conducted. All participants received the same intervention and survey questions. The analytical focus was on within-person changes caused by the workshop intervention. Results: Among media professionals, the workshop intervention increased perceived knowledge sufficiency about RRS, raised awareness that RRS can save lives, decreased insecurities related to RRS, and reduced the misperception that there are no clear recommendations about RRS. Limitations: Despite the missing randomization of workshop participants, the repeated measures design allows to speak to the short-term changes in RRS. Conclusion: An RRS workshop intervention has multifaceted positive effects on media professionals. The study found no evidence for unintended effects of the intervention.

scholarly journals Short-Term Research Experience (SRE) in the Traditional Lab: Qualitative and Quantitative Data on Outcomes

2018 ◽  
Vol 17 (4) ◽  
pp. ar64 ◽  
Author(s):  
David I. Hanauer ◽  
Justin Nicholes ◽  
Fang-Yu Liao ◽  
Aaron Beasley ◽  
Heather Henter
Keyword(s):  
Student Perceptions ◽  
Undergraduate Students ◽  
Repeated Measures ◽  
Research Experience ◽  
Short Term ◽  
Repeated Measures Design ◽  
Personal Investment ◽  
Matching Technique ◽  
Before And After ◽  
Survey Results

The San Diego Biodiversity Project introduces undergraduate students at four different 2- and 4-year schools to a short-term research experience (SRE) that was implemented as a module in the last third of a traditional laboratory course. The study assesses the qualities of this SRE for students using three different methods. Twenty-one participants were interviewed about their experiences in the traditional and research components of their course. In a repeated-measures design, 124 participants took the Persistence in the Sciences (PITS) survey immediately before and after their participation in the SRE. Finally, using a propensity score matching technique, PITS survey results for SRE students were compared with those for students in a course-based research experience (CRE). Student perceptions of the traditional lab and the SRE are different—students appreciate learning basic processes and procedures in the traditional lab, but they express having personal investment in and a sense of participating in science in the SRE. Significant increases were found for the variable of Project Ownership in the SRE condition over the traditional lab, but SRE outcomes were lower than CRE outcomes. Although the SRE may not provide the benefits of a CRE, it is a serious option for expanding access to authentic research.

On the prediction of crystal morphology. III. Equilibrium and growth behaviour of crystal faces containing multiple connected nets

1999 ◽  
Vol 55 (1) ◽  
pp. 84-94 ◽  
Author(s):  
R. F. P. Grimbergen ◽  
P. Bennema ◽  
H. Meekes
Keyword(s):  
Growth Rate ◽  
Monte Carlo ◽  
Growth Rates ◽  
Crystal Morphology ◽  
Crystal Habit ◽  
Growth Behaviour ◽  
Equilibrium Conditions ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Surface Phases

In this paper, the equilibrium and growth behaviour of faces (hkl) with more than one connected net is studied. It is shown that for these types of orientation different surface phases exist under equilibrium conditions as a function of temperature. Depending on the exact bonding topology at the surface, flat, rough or disordered flat phases are found. Moreover, the growth rate R_{hkl} of such faces can differ significantly from the usually calculated relative growth rates based on the attachment energy. Monte Carlo simulations confirm the results from the Hartman–Perdok analyses and offer a tool for the prediction of the crystal habit as a function of supersaturation.

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