scholarly journals A Comparison of Variability in Two Cassin’s Auklet (Ptychoramphus aleuticus) Colonies Using Spline-based Nonparametric Models

2013 ◽  
Vol 4 (1) ◽  
pp. 63-85
Author(s):  
Dean Koch
Keyword(s):  
Growth Rate ◽  
Reproductive Performance ◽  
Coefficient Of Variation ◽  
Small Scale ◽  
Regression Spline ◽  
Ecological Variability ◽  
Nonparametric Models ◽  
Cassin's Auklet ◽  
Ptychoramphus Aleuticus ◽  
Over Time

While variability in the reproductive performance of a population over time is a familiar and useful concept to ecologists, it can be difficult to capture mathematically. Commonly used ecological variability statistics, such as the standard deviation of the logarithm and coefficient of variation, discard the time-ordering of observations and consider only the unordered response variable values. We used a relatively new methodology, the cubic regression spline (a flexible curve fitted to a scatterplot of data), both to illustrate trends in reproductive performance over time and to explore the utility of the cubic regression spline roughness penalty (J) as a statistic for measuring variability while retaining time-ordering information. We concluded that although J measures variability in a mathematical sense, it can be inappropriate in a population ecology context because of sensitivity to small-scale fluctuations. To illustrate our methodology, we used the CRS approach in an analysis of historical data from two Cassin’s Auklet colonies located on Frederick and Triangle Islands in coastal BC, developing a model for the annual mean nestling growth rate on each island over seven contiguous years. Model selection indicated a complex (nonlinear) trend in growth rate on both islands. We report higher variability in the resident bird population of Triangle Island than Frederick Island, based on a comparison of the fitted curves, and the values of the coefficient of variation and population variability summary statistics.

scholarly journals Growth Rate and Nutrient Uptake of Basil in Small-scale Hydroponics

HortScience ◽  
2020 ◽  
Vol 55 (4) ◽  
pp. 507-514
Author(s):  
Elisa Solis-Toapanta ◽  
Paul Fisher ◽  
Celina Gómez
Keyword(s):  
Growth Rate ◽  
Nutrient Uptake ◽  
Nutrient Solution ◽  
Indoor Environment ◽  
Nutrient Concentration ◽  
Management Strategies ◽  
Dry Mass ◽  
Small Scale ◽  
Hydroponic Systems ◽  
Over Time

To identify practices that may simplify the use of small-scale hydroponic systems for indoor gardening, we compared two nutrient solution management treatments for basil (Ocimum basilicum) production. Experiments were conducted for 8 weeks to evaluate the effect of biweekly replacement of the nutrient solution (W) vs. biweekly fertilizer addition without nutrient solution replacement (W/O) on growth and nutrient uptake of basil ‘Genovese Compact’ grown in either a greenhouse or an indoor environment. Greenhouse day/night temperature was 29/24 ± 4 °C, relative humidity (RH) was 65 ± 4%, and daily light integral (DLI) was 26.1 mol·m‒2·d‒1. The indoor environment had a constant ambient temperature of 21 °C, RH of 65%, and DLI of 9 mol·m‒2·d‒1 provided by broadband white lamps. Four plants were grown in 7.6-L replicate hydroponic systems, with 178 mg·L‒1 N from a complete nutrient solution in two experimental runs. Shoot fresh and dry mass, leaf number, and leaf area showed an increasing quadratic trend over time when plants were grown in the greenhouse. In contrast, growth over time was linear for plants grown indoors. Within each environment, solution management treatment did not affect growth, indicating that the simpler W/O strategy was adequate under these conditions. Plants grown in the greenhouse required more frequent refill water applications compared with indoors, which resulted in three to four times more refill water applied. Because indoor-grown plants had a decreased growth rate, nutrient uptake rate, and volume of water applied compared with plants grown in the greenhouse, electrical conductivity (EC) for the W/O treatment increased over time. Final nutrient solution concentration was highest for indoor-grown plants under the W/O treatment, and final tissue nutrient concentration was higher for plants grown indoors compared with the greenhouse. Final nutrient uptake (dry mass × nutrient concentration) was higher for plants grown in the greenhouse rather than indoors. Considering that EC increased in the solution of indoor-grown plants under W/O, an appropriate strategy using this treatment would require reducing fertilizer input indoors. To refine simple and robust fertilizer management strategies for indoor gardeners, further research is needed to test variables such as different plant species, cultivars, and water qualities.

AGE, WEIGHT, BACKFAT AND TIME OF MATING EFFECTS ON PERFORMANCE OF GILTS

1990 ◽  
Vol 70 (2) ◽  
pp. 469-481 ◽  
Author(s):  
L. G. YOUNG ◽  
G. J. KING ◽  
J. S. WALTON ◽  
I. McMILLAN ◽  
M. KLEVORICK
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Reproductive Performance ◽  
Coefficient Of Variation ◽  
Sexual Maturity

An experiment was conducted involving 429 gilts that were managed to stimulate estrus after 140 d of age, bred at first, second or third observed estrus and to study factors relating to estrus and reproductive performance to weaning of the first litter. The average at first estrus followed by the coefficient of variation (%) in parentheses were: age 167.2 d (11.8); weight 106.8 kg (15.5); backfat 19.1 mm (17.8); backfat/weight 0.18 (16.2) and weight/age 0.64 (11.5). Sixty-two and one-half percent of the gilts exhibiting estrus did so between 140 and 170 d of age. Fifty-eight percent of the gilts exhibited estrus prior to 180 d of age and were less than 110 kg liveweight. There were relatively low correlations between indices of growth rate and fatness with age at first estrus. Reproductive performance was not enhanced by delaying breeding to second or third estrus after puberty. Key words: Pigs, reproduction, sexual maturity, age, weight, backfat

Cassin's Auklet (Ptychoramphus aleuticus)

2020 ◽  
Author(s):  
David G. Ainley ◽  
D. A. Manuwal ◽  
Josh Adams ◽  
A. C. Thoresen
Keyword(s):  
Cassin's Auklet ◽  
Ptychoramphus Aleuticus

scholarly journals Assessment of the Growth and Reproductive Performance of Cloned Pietrain Boars

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2053
Author(s):  
Junsong Shi ◽  
Baohua Tan ◽  
Lvhua Luo ◽  
Zicong Li ◽  
Linjun Hong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Performance ◽  
Reproductive Performance ◽  
Semen Quality ◽  
Small Body ◽  
Economic Benefits ◽  
Large Animal ◽  
Significant Difference ◽  
F1 Progeny

How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.

scholarly journals Theology at Thresholds: Learning from a Practice ‘In Transition’

2017 ◽  
Vol 4 (1) ◽  
pp. 45-62 ◽  
Author(s):  
Rachel Muers ◽  
Rhiannon Grant
Keyword(s):  
Decision Making ◽  
The Other ◽  
Small Scale ◽  
Theological Ethics ◽  
Reciprocal Influence ◽  
Core Practices ◽  
Recent Developments ◽  
Collective Process ◽  
The One ◽  
Over Time

Recent developments in contemporary theology and theological ethics have directed academic attention to the interrelationships of theological claims, on the one hand, and core community-forming practices, on the other. This article considers the value for theology of attending to practice at the boundaries, the margins, or, as we prefer to express it, the threshold of a community’s institutional or liturgical life. We argue that marginal or threshold practices can offer insights into processes of theological change – and into the mediation between, and reciprocal influence of, ‘church’ and ‘world’. Our discussion focuses on an example from contemporary British Quakerism. ‘Threshing meetings’ are occasions at which an issue can be ‘threshed out’ as part of a collective process of decision-making. Drawing on a 2015 small-scale study (using a survey and focus group) of British Quaker attitudes to and experiences of threshing meetings, set in the wider context of Quaker tradition, we interpret these meetings as a space for working through – in context and over time – tensions within Quaker theology, practice and self-understandings, particularly those that emerge within, and in relation to, core practices of Quaker decision-making.

Decomposition of Growth Curves into Growth Rate and Acceleration: a Novel Procedure to Monitor Bacterial Growth and the Time-Dependent Effect of Antimicrobials

2021 ◽  
Author(s):  
M. Luisa Navarro-Pérez ◽  
M. Coronada Fernández-Calderón ◽  
Virginia Vadillo-Rodríguez
Keyword(s):  
Growth Rate ◽  
Mathematical Models ◽  
Bacterial Growth ◽  
Time Course ◽  
Antimicrobial Agents ◽  
Numerical Procedure ◽  
Growth Curves ◽  
Predictive Microbiology ◽  
Insight Into ◽  
Over Time

In this paper, a simple numerical procedure is presented to monitor the growth of Streptococcus sanguinis over time in the absence and presence of propolis, a natural antimicrobial. In particular, it is shown that the real-time decomposition of growth curves obtained through optical density measurements into growth rate and acceleration can be a powerful tool to precisely assess a large range of key parameters [ i.e. lag time ( t 0 ), starting growth rate ( γ 0 ), initial acceleration of the growth ( a 0 ), maximum growth rate ( γ max ), maximum acceleration ( a max ) and deceleration ( a min ) of the growth and the total number of cells at the beginning of the saturation phase ( N s )] that can be readily used to fully describe growth over time. Consequently, the procedure presented provides precise data of the time course of the different growth phases and features, which is expected to be relevant, for instance, to thoroughly evaluate the effect of new antimicrobial agents. It further provides insight into predictive microbiology, likely having important implications to assumptions adopted in mathematical models to predict the progress of bacterial growth. Importance: The new and simple numerical procedure presented in this paper to analyze bacterial growth will possibly allow identifying true differences in efficacy among antimicrobial drugs for their applications in human health, food security, and environment, among others. It further provides insight into predictive microbiology, likely helping in the development of proper mathematical models to predict the course of bacterial growth under diverse circumstances.

scholarly journals Analysis of Challenges Facing Rice Processing in Nigeria

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
A. S. Ajala ◽  
A. Gana
Keyword(s):  
Decision Making ◽  
Growth Rate ◽  
Developing Countries ◽  
Population Growth Rate ◽  
Developed Countries ◽  
Small Scale ◽  
Basic Information ◽  
Food Crop ◽  
Important Food ◽  
Rice Processing

Rice is the most economically important food crop in many developing countries and has also become a major crop in many developed countries where its consumption has increased considerably. It has become necessary to meet the demand of the world’s current population growth rate, and the least costly means for achieving this aim is to increase rice productivity, wherever possible. The main challenges encountered by rice processors in Nigeria are to find appropriate solutions for quality rice processing. Therefore this work provides basic information about the challenges of rice processing and focuses on the challenges faced by the small scale rice processors and reasons for continuous rice importation with a view to guiding decision-making to be self-sufficient in rice production, thereby making some improvement in Nigerian economy.

The abundance and effects of ticks (Ixodes uriae) on nestling Cassin's Auklets (Ptychoramphus aleuticus) at Triangle Island, British Columbia

1996 ◽  
Vol 74 (8) ◽  
pp. 1585-1589 ◽  
Author(s):  
Y. E. Morbey
Keyword(s):  
Tick Infestation ◽  
Host Record ◽  
New Host ◽  
Ixodes Uriae ◽  
New Host Record ◽  
Cassin's Auklet ◽  
Peak Mass ◽  
The Common ◽  
Ptychoramphus Aleuticus ◽  
Wing Growth

Cassin's Auklet (Ptychoramphus aleuticus) nestlings hosted the common seabird tick Ixodes uriae. This is a new host record for this species of tick. Ixodes uriae were distributed nonrandomly on nestlings within and among sites. Soil substrate was thought to be an important factor influencing tick distribution. Nestlings with severe tick infestation had slower rates of wing growth, reached peak mass at older ages, and fledged with shorter wings at older ages than nestlings with fewer ticks. By remaining in the nest for longer periods, nestlings with severe tick infestation may have been compensating for the delay in wing development.

Sign in / Sign up

Export Citation Format

Share Document