scholarly journals Bioenergetic Model Sensitivity to Diet Diversity Across Space, Time and Ontogeny

2021 ◽  
Vol 8 ◽  
Author(s):  
Christopher L. Lawson ◽  
Matthew D. Taylor ◽  
James A. Smith ◽  
Nicholas L. Payne ◽  
Jayson M. Semmens ◽  
...  
Keyword(s):  
Growth Rate ◽  
Consumption Rate ◽  
Accurate Estimation ◽  
Ontogenetic Changes ◽  
Bioenergetic Model ◽  
Diet Diversity ◽  
Diet Variability ◽  
Primary Model ◽  
Model Scenarios

Consumption is the primary trophic interaction in ecosystems and its accurate estimation is required for reliable ecosystem modeling. When estimating consumption, species’ diets are commonly assumed to be the average of those that occur among habitats, seasons, and life stages which introduces uncertainty and error into consumption rate estimates. We present a case study of a teleost (Yellowfin Bream Acanthopagrus australis) that quantifies the potential error in consumption (in mass) and growth rate estimates when using diet data from different regions and times and ignoring ontogenetic variability. Ontogenetic diet trends were examined through gut content analysis (n = 1,130 fish) and incorporated into a bioenergetic model (the “primary” model) that included diet variability (n = 144 prey sources) and ontogenetic changes in metabolism (1–7 year) to estimate lifetime consumption. We quantified error by building nine model scenarios that each incorporated different spatiotemporal diet data of four published studies. The model scenarios produced individual lifetime consumption estimates that were between 25% lower and 15% higher than the primary model (maximum difference was 53%, range 11.7–17.8 kg). When consumption (in mass) was held constant, differences in diet quality among models caused a several-fold range in growth rate (0.04–1.07 g day–1). Our findings showcase the large uncertainty in consumption rate estimates due to diet diversity, and illustrate that caution is required when considering bioenergetic results among locations, times, and ontogeny.

Ontogeny in the steinmanellines (Bivalvia: Trigoniida): an intra- and interspecific appraisal using the Early Cretaceous faunas from the Neuquén Basin as a case study

Paleobiology ◽  
2021 ◽  
pp. 1-23
Author(s):  
Pablo S. Milla Carmona ◽  
Dario G. Lazo ◽  
Ignacio M. Soto
Keyword(s):  
Trajectory Analysis ◽  
Sedentary Lifestyle ◽  
Shape Change ◽  
Shell Shape ◽  
Shape Variation ◽  
Ontogenetic Changes ◽  
Ontogenetic Trajectories ◽  
Higher Genus ◽  
Gradual Decay

Abstract Despite the paleontological relevance and paleobiological interest of trigoniid bivalves, our knowledge of their ontogeny—an aspect of crucial evolutionary importance—remains limited. Here, we assess the intra- and interspecific ontogenetic variations exhibited by the genus Steinmanella Crickmay (Myophorellidae: Steinmanellinae) during the early Valanginian–late Hauterivian of Argentina and explore some of their implications. The (ontogenetic) allometric trajectories of seven species recognized for this interval were estimated from longitudinal data using 3D geometric morphometrics, segmented regressions, and model selection tools, and then compared using trajectory analysis and allometric spaces. Our results show that within-species shell shape variation describes biphasic ontogenetic trajectories, decoupled from ontogenetic changes shown by sculpture, with a gradual decay in magnitude as ontogeny progresses. The modes of change characterizing each phase (crescentic growth and anteroposterior elongation, respectively) are conserved across species, thus representing a feature of Steinmanella ontogeny; its evolutionary origin is inferred to be a consequence of the rate modification and allometric repatterning of the ancestral ontogeny. Among species, trajectories are more variable during early ontogenetic stages, becoming increasingly conservative at later stages. Trajectories’ general orientation allows recognition of two stratigraphically consecutive groups of species, hinting at a potentially higher genus-level diversity in the studied interval. In terms of functional morphology, juveniles had a morphology more suited for active burrowing than adults, whose features are associated with a sedentary lifestyle. The characteristic disparity of trigoniids could be related to the existence of an ontogenetic period of greater shell malleability betrayed by the presence of crescentic shape change.

scholarly journals Growth of Listeria monocytogenes in Thawed Frozen Foods

2017 ◽  
Vol 80 (3) ◽  
pp. 447-453 ◽  
Author(s):  
Ai Kataoka ◽  
Hua Wang ◽  
Philip H. Elliott ◽  
Richard C. Whiting ◽  
Melinda M. Hayman
Keyword(s):  
Growth Rate ◽  
Listeria Monocytogenes ◽  
Growth Rates ◽  
Storage Temperature ◽  
Growth Parameters ◽  
Quadratic Model ◽  
Lag Phase ◽  
Frozen Foods ◽  
Phase Duration ◽  
Primary Model

ABSTRACT The growth characteristics of Listeria monocytogenes inoculated onto frozen foods (corn, green peas, crabmeat, and shrimp) and thawed by being stored at 4, 8, 12, and 20°C were investigated. The growth parameters, lag-phase duration (LPD) and exponential growth rate (EGR), were determined by using a two-phase linear growth model as a primary model and a square root model for EGR and a quadratic model for LPD as secondary models, based on the growth data. The EGR model predictions were compared with growth rates obtained from the USDA Pathogen Modeling Program, calculated with similar pH, salt percentage, and NaNO2 parameters, at all storage temperatures. The results showed that L. monocytogenes grew well in all food types, with the growth rate increasing with storage temperature. Predicted EGRs for all food types demonstrated the significance of storage temperature and similar growth rates among four food types. The predicted EGRs showed slightly slower rate compared with the values from the U.S. Department of Agriculture Pathogen Modeling Program. LPD could not be accurately predicted, possibly because there were not enough sampling points. These data established by using real food samples demonstrated that L. monocytogenes can initiate growth without a prolonged lag phase even at refrigeration temperature (4°C), and the predictive models derived from this study can be useful for developing proper handling guidelines for thawed frozen foods during production and storage.

The Future of the Nigerian Agricultural Industries: A Case Study of Oil Palm Production in Edo State

2013 ◽  
Vol 824 ◽  
pp. 561-567 ◽  
Author(s):  
U.J. Udosen ◽  
A.P. Ugboya
Keyword(s):  
Growth Rate ◽  
Oil Palm ◽  
Frequency Distributions ◽  
Factors Influencing ◽  
The Future ◽  
Edo State ◽  
Agricultural Industries ◽  
Fresh Fruit Bunches ◽  
Planting Materials

This study analyzes oil palm production from 2001 - 2008 in Edo State, with a view of establishing the future of Nigerian Agricultural oil palm industries. The specific objectives were to identify and quantify the factors influencing the production of oil palm, reveal the constraints to the production of oil palm; analyze the viability of oil palm production as an investment and predict the future of oil palm enterprise in Edo State. Three Local Government Areas of high oil palm concentration in Edo State were covered. Ninety selected oil palm producers from nine villages in the study area were selected. Frequency distributions and multiple regression analysis were used to analyze the results. The results showed that for the period under review (2001 - 2008) on a per hectare basis, seedlings cost, and labour cost were significant inputs, positively influencing the production of oil palm in the Edo State. A growth rate of 6.2% and 23.5% were projected for oil palm with reference to palm oil and fresh fruit bunches (FFB), respectively, up to the year 2020, an indication that oil palm production in the State is viable and the future is bright. The study revealed that inadequate storage facilities, poor planting materials and lack of government assistance, among others, are major bottlenecks in oil palm production in Edo State. However, since oil palm production in Edo State is viable, it is an indication that the future of Nigerian Agricultural Industries is bright.

scholarly journals Sectoral Volatility, Development, and Governance: A Case Study of Pakistan

2006 ◽  
Vol 45 (4II) ◽  
pp. 797-817
Author(s):  
Toseef Azid ◽  
Naeem Khaliq ◽  
Muhammad Jamil
Keyword(s):  
Growth Rate ◽  
Structural Change ◽  
Service Sector ◽  
Structural Changes ◽  
Agricultural Sector ◽  
Green Revolution ◽  
Rate Of Growth ◽  
Agriculture Industry ◽  
The Future

Development of overall economy of any country largely depends upon the characteristics of different prominent sectors such as agriculture, industry, services, etc. Sharp structural change in prominent sectors are experienced by the Pakistan’s economy during the last four decades, in which industrial and service sector have exhibited an extra ordinary rate of growth, while the agricultural sector did not shown that rate of growth which was experienced during the time of green revolution. Due to these structural changes in the prominent sectors volatility of growth rate has been experienced by the economy. To the extent that most of the recent volatility in growth rate of GDP can be attributed to the increasing share of the some volatility of the some prominent sectors, the analysis of their volatility can be useful in providing some enlightenment on the factors behind this phenomenon and its implications for the formulation of the policy in the future.

Promoting geotourism a case study from Northeast Iceland

2010 ◽  
Author(s):  
John S. Hull
Keyword(s):  
Growth Rate ◽  
Foreign Currency ◽  
Leisure Activity ◽  
Natural Image ◽  
Annual Growth Rate ◽  
Horseback Riding ◽  
Outdoor Activities ◽  
The Third ◽  
First Time

Iceland is becoming a popular venue for nature-based tourism enthusiasts interested in exploring Arctic environments for scenic and recreational purposes (ITB 2009; Gossling and Alkimou 2006). Visitation to Iceland is expanding exponentially, generating significant revenue and income, making tourism the third largest foreign currency earner for the Icelandic economy. In 2006, total tourism receipts were measured at 47 billion Icelandic kroner (ISK), contributing 4.1 per cent to the nation’s GDP, and providing 12.7 per cent of the country’s income from foreign sources (Rannsoknir and Radgjof Ferdapjonustunnar 2008). In 2007, over 530,000 international tourists visited Iceland with over 80 per cent first-time visitors mainly from Europe and North America (Rannsoknir and Radgjof Ferdapjonustunnar 2008). The Icelandic Tourism Board (ITB 2007) identifies that the vast natural resources - glaciers, volcanos, geysers, and untamed wilderness - are some of the most important reasons contributing to the present 7 percent annual growth rate in visitation (Gossling and Hultman 2006). The most popular leisure activity of visitors is nature observation (ITB 2007). Outdoor activities such as camping, hiking, boat tours, jeep and glacier tours, snowmobile excursions, and horseback riding are also popular throughout the island. Overall, visitor motivation to Iceland is based on romanticized notions of the unique wilderness and the grandness of the landscape and tourist experiences that recreate a ‘natural’ image of the island (Gossling and Alkimou 2006; Gossling and Hultman 2006).

scholarly journals Gastronomy Tourism Growth in Malaysia: A Case Study of Malay Restaurants Performance in Klang Valley

2020 ◽  
Vol 10 ◽  
pp. 8-21
Author(s):  
Raja Puteri Saadiah Raja Abdullah ◽  
Siti Suriawati Isa
Keyword(s):  
Growth Rate ◽  
Growth Performance ◽  
Soft Power ◽  
Rate Performance ◽  
Business Growth ◽  
Internal Factors ◽  
Factors Affecting ◽  
Klang Valley ◽  
Survey Questionnaires

Today one of the most popular niche tourism markets is gastronomy tourism. The popularity of gastronomy tourism is also called as soft power approaches by some tourism scholars. This niche market is part of cultural and ecotourism market. Malaysia is recognized as a multi-ethnic and multi cultural country that includes countless ethnics such as Malay, Chinese, Indian and others. Although Malay leads the major ethnics in Malaysia, Malay restaurant less likely can stay longer in the industry. There are several factors from previous cases involve in Malay restaurants that result to this ethnic’s restaurant fail to survive. Since Malaysia is a multi-ethnic country the food in Malaysia have combination from all ethnics and unique in its own way. Each state in Malaysia has their own dishes and some dishes may diff er from another state. Since Malay or Bumi putra ethnic comprises the biggest ethnic in Malaysia with more than half of the country’s population, the objective of this study was to analyze the internal factors affecting business growth performance in Malay ethnic restaurant. Survey questionnaires were distributed to selected Malay restaurants to find out about their growth rate performance.

A laboratory investigation of Paulinia acuminata (DeGeer) (Orthoptera: Acrididae) as a biological control agent for Salvinia molesta

1979 ◽  
Vol 69 (1) ◽  
pp. 111-114 ◽  
Author(s):  
I. F. Chisholm
Keyword(s):  
Biological Control ◽  
Growth Rate ◽  
Plant Tissue ◽  
Feeding Rate ◽  
Consumption Rate ◽  
Biological Control Agent ◽  
Control Agent ◽  
Salvinia Molesta ◽  
Population Densities ◽  
Lake Kariba

AbstractThe feeding rate of nymphs of Paulinia acuminata (Deg.) on Salvinia molesta was studied in the laboratory using single nymphs on different numbers of Salvinia leaves. Each successive instar ate more plant tissue, but at population densities likely to occur in nature it was unlikely that consumption rate could match the natural Salvinia growth rate. The controlling effect of Paulinia on Salvinia in Lake Kariba, Rhodesia, may therefore be negligible.

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