In Vivo Bone Strain and Ontogenetic Growth Patterns in Relation to Life‐History Strategies and Performance in Two Vertebrate Taxa: Goats and Emu

2006 ◽  
Vol 79 (1) ◽  
pp. 57-72 ◽  
Author(s):  
Russell P. Main ◽  
Andrew A. Biewener
Keyword(s):  
Life History ◽  
Growth Patterns ◽  
Life History Strategies ◽  
Bone Strain ◽  
And Performance

Comparing Early Life History Strategies of Pomatomus saltatrix: a Global Approach

1996 ◽  
Vol 47 (2) ◽  
pp. 365 ◽  
Author(s):  
F Juanes ◽  
JA Hare ◽  
AG Miskiewicz
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Early Life History ◽  
Growth Patterns ◽  
Life History Strategies ◽  
Eastern Coast ◽  
The South ◽  
Pomatomus Saltatrix ◽  
South Eastern

Pomatomus saltatrix (Pisces:Pomatomidae) is a highly migratory, continental-shelf species with a worldwide subtropical distribution including the eastern coast of North America, the Gulf of Mexico, Mediterranean Sea, Black Sea, north-western Africa, the eastern coast of South America, the south-eastern coast of South Africa, and the south-eastern and south-westem coasts of Australia. This paper summarizes available life history information from the different regions where P. saltatrix occurs, with a focus on the early life history. The basic physical oceanography of these regions is also reviewed to elucidate patterns in larval transport. Comparison of these populations suggests that there are commonalties: adults migrate to spawning grounds; eggs and larvae are typically advected along-shore to juvenile nursery habitats; juveniles recruit to inshore habitats at a similar size, and there they grow rapidly and are mainly piscivorous, feeding primarily on atherinids and engraulids. There are also a number of life history traits that are quite variable among populations: the number of annual reproductive peaks, the number of juvenile cohorts, adult growth patterns and reproductive parameters. Comparison of these life history patterns leads to several non-exclusive hypotheses as to the adaptive significance of variations in life history traits. The goal is to identify areas where more research is needed to assess the degree to which populations of a global species are adapted to their local environment.

scholarly journals Growth patterns and life-history strategies in Placodontia (Diapsida: Sauropterygia)

2015 ◽  
Vol 2 (7) ◽  
pp. 140440 ◽  
Author(s):  
Nicole Klein ◽  
James M. Neenan ◽  
Torsten M. Scheyer ◽  
Eva Maria Griebeler
Keyword(s):  
Life History ◽  
Bone Tissue ◽  
Developmental Plasticity ◽  
Growth Models ◽  
Age At Onset ◽  
Growth Curves ◽  
Growth Patterns ◽  
Tissue Type ◽  
Life History Strategies ◽  
Long Bone

Placodontia is a clade of durophagous, near shore marine reptiles from Triassic sediments of modern-day Europe, Middle East and China. Although much is known about their primary anatomy and palaeoecology, relatively little has been published regarding their life history, i.e. ageing, maturation and growth. Here, growth records derived from long bone histological data of placodont individuals are described and modelled to assess placodont growth and life-history strategies. Growth modelling methods are used to confirm traits documented in the growth record (age at onset of sexual maturity, age when asymptotic length was achieved, age at death, maximum longevity) and also to estimate undocumented traits. Based on these growth models, generalized estimates of these traits are established for each taxon. Overall differences in bone tissue types and resulting growth curves indicate different growth patterns and life-history strategies between different taxa of Placodontia. Psephoderma and Paraplacodus grew with lamellar-zonal bone tissue type and show growth patterns as seen in modern reptiles. Placodontia indet. aff. Cyamodus and some Placodontia indet. show a unique combination of fibrolamellar bone tissue regularly stratified by growth marks, a pattern absent in modern sauropsids. The bone tissue type of Placodontia indet. aff. Cyamodus and Placodontia indet. indicates a significantly increased basal metabolic rate when compared with modern reptiles. Double lines of arrested growth, non-annual rest lines in annuli, and subcycles that stratify zones suggest high dependence of placodont growth on endogenous and exogenous factors. Histological and modelled differences within taxa point to high individual developmental plasticity but sexual dimorphism in growth patterns and the presence of different taxa in the sample cannot be ruled out.

Mode of growth and life-history strategies of a Late Ordovician halysitid coral

1991 ◽  
Vol 65 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Dong-Jin Lee ◽  
Robert J. Elias
Keyword(s):  
Life History ◽  
Substrate Surface ◽  
Colony Growth ◽  
High Energy ◽  
Growth Patterns ◽  
Life History Strategies ◽  
Large Area ◽  
Physical Strength ◽  
Passive Flow ◽  
Vertical Growth Rate

The upper surface of the corallum ofCatenipora rubrawas often at or just above the sediment-water interface during life. The vertical growth rate was barely sufficient to keep pace with background sedimentation and possible subsidence of the corallum. Therefore, the colonies were in constant danger of being covered by influxes of sediment, especially during storms. This was compensated by the ability of polyps to respond to sedimentation events and by certain aspects of colony growth. Rapid regeneration following partial mortality involved budding of uninjured polyps and rejuvenation of damaged individuals, in some cases accompanied by a type of axial increase not previously known in tabulate corals. Rapid lateral expansion was possible because small, “immature” polyps could bud and grow in a reptant manner.Interconnected ranks of the cateniform corallum served to dam shifting sediment at the periphery of the colony. Lacunae within the colony were reservoirs for material that breached peripheral ranks and for sediment that settled on the ranks and was rejected by polyps or removed by passive flow. Polyps comprising the colony were distributed over a large area of the substrate surface, thereby decreasing the probability of complete mortality during sedimentation events and increasing the probability that a sufficient number of individuals would survive to ensure optimum regeneration. The corallum, anchored in the substrate and with sediment filling the lacunae, provided a broad, stable base during high-energy events.It remains to be established how widespread these growth patterns and strategies were among other corals with cateniform colonies, a form that appeared in many unrelated stocks. Most previous workers emphasized physical strength when considering functional morphology, following a tacit assumption that the corallum rose high above the substrate and was therefore susceptible to breakage during high-energy events. An understanding of the origin of cateniform patterns and the phylogeny of these corals requires knowledge of their modes of growth and life-history strategies, which were genetically as well as environmentally controlled.

scholarly journals A tale of two species: climate-competition tradeoffs shape range limits according to tree life-history strategies

2021 ◽  
Author(s):  
Jonathan Schurman ◽  
Pavel Janda ◽  
Milos Rydval ◽  
Martin Mikolas ◽  
Miroslav Svoboda ◽  
...  
Keyword(s):  
Life History ◽  
Interspecific Competition ◽  
Ring Width ◽  
Empirical Support ◽  
Growth Patterns ◽  
Range Limits ◽  
Life History Strategies ◽  
Range Limit ◽  
Lower Range ◽  
Cold Tolerant

Adapting for competitiveness versus climatic stress tolerance constitutes a primary trade-off differentiating tree life-history strategies. This tradeoff likely influences where species’ range-limits occur, but such links are data-demanding to study and key mechanisms lack empirical support. Using an exceptionally rich dendroecological network, we assessed spatial variation in climate and competition effects on Picea abies and Fagus sylvatica throughout the Carpathian Ecoregion. Ring width synchrony aided in diagnosing how the prevalence of resource-limited (competition) and sink-limited (climate) growth changes with altitude and community composition. Contrasting growth patterns towards respective upper and lower range limits of Fagus and Picea reflected tradeoffs between competitive vs. cold-tolerant strategies. Fagus performance declined with altitudinal increases in climate sensitivity, but improved under interspecific competition. Picea growth increased towards the species’ lower range limit, but declined under interspecific competition. Warmer temperatures likely benefit competitively stronger species at mid elevations and thus imply range reductions for alpine conifers.

scholarly journals Phenotypic and metabolic plasticity shapes life-history strategies under combinations of abiotic stresses

2018 ◽  
Author(s):  
Lidor Shaar-Moshe ◽  
Ruchama Hayouka ◽  
Ute Roessner ◽  
Zvi Peleg
Keyword(s):  
Life History ◽  
Abiotic Stresses ◽  
Germination Rate ◽  
Brachypodium Distachyon ◽  
Life History Strategies ◽  
Plant Fitness ◽  
Metabolic Plasticity ◽  
Trade Offs ◽  
And Performance ◽  
Stress Combinations

AbstractPlants developed various reversible and non-reversible acclimation mechanisms to cope with the multifaceted nature of abiotic stress combinations. We hypothesized that in order to endure these stress combinations, plants elicit distinctive acclimation strategies through specific trade-offs between reproduction and defense. To investigateBrachypodium distachyonacclimation strategies to combinations of salinity, drought and heat, we applied a system biology approach, integrating physiological, metabolic and transcriptional analyses. We analyzed the trade-offs among functional and performance traits, and their effects on plant fitness. A combination of drought and heat resulted in escape strategy, while under a combination of salinity and heat, plants exhibited avoidance strategy. On the other hand, under combinations of salinity and drought, with or without heat stress, plant fitness (i.e. germination rate of subsequent generation) was severely impaired. These results indicate that under combined stresses, plants’ life-history strategies were shaped by the limits of phenotypic and metabolic plasticity and the trade-offs between traits, thereby giving raise to distinct acclimations. Our findings provide a mechanistic understanding of plant acclimations to combinations of abiotic stresses and shed light on the different life-history strategies that can contribute to grass fitness and possibly to their dispersion under changing environments.

scholarly journals Lifelong divergence of growth patterns in Arctic charr life history strategies: implications for sustainable fisheries in a changing climate

2021 ◽  
Author(s):  
Gabrielle Grenier ◽  
Ross F. Tallman
Keyword(s):  
Life History ◽  
Life Histories ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Growth Increment ◽  
Linear Increase ◽  
Growth Patterns ◽  
Life History Strategies ◽  
Changing Climate ◽  
Summer Growth

Arctic charr (Salvelinus alpinus Linneaus, 1758) are phenotypically variable with multiple life history strategies including anadromous and freshwater resident individuals. The mechanism determining life history is believed to be set early in life. Anadromous individuals show greater seasonality in growth and feeding after the first seaward migration relative to resident conspecifics. We used otolith growth increment measurements to estimate lifelong growth patterns for 355 individuals with anadromous or resident life history from four populations within Cumberland Sound, Nunavut. Using a general and a generalized linear model, we discovered a linear increase (estimate = 0.006) in growth for both Arctic charr life histories between 1990 and 2016. Resident Arctic charr have lower annual growth (estimate = -0.176) and show a decrease in the annual proportion of summer growth as they age (estimate = -0.042) while their anadromous counterparts maintain a higher seasonality in their growth patterns with age. This suggests that growth is indeed important in life history trajectory for Arctic charr and that seasonal growth patterns differ among life histories. The results highlight the importance of improving our understanding of mechanisms influencing life history trajectory in Arctic charr to ensure sustainability of harvested Arctic charr populations in a changing climate.

scholarly journals The Implications of Regulatory Framework for Topical Semisolid Drug Products: From Critical Quality and Performance Attributes towards Establishing Bioequivalence

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 710
Author(s):  
Tanja Ilić ◽  
Ivana Pantelić ◽  
Snežana Savić
Keyword(s):  
Statistical Power ◽  
Failure Modes ◽  
In Vitro Release ◽  
Optimal Number ◽  
Drug Products ◽  
Pharmaceutical Equivalence ◽  
And Performance ◽  
Low Sensitivity

Due to complex interdependent relationships affecting their microstructure, topical semisolid drug formulations face unique obstacles to the development of generics compared to other drug products. Traditionally, establishing bioequivalence is based on comparative clinical trials, which are expensive and often associated with high degrees of variability and low sensitivity in detecting formulation differences. To address this issue, leading regulatory agencies have aimed to advance guidelines relevant to topical generics, ultimately accepting different non-clinical, in vitro/in vivo surrogate methods for topical bioequivalence assessment. Unfortunately, according to both industry and academia stakeholders, these efforts are far from flawless, and often upsurge the potential for result variability and a number of other failure modes. This paper offers a comprehensive review of the literature focused on amending regulatory positions concerning the demonstration of (i) extended pharmaceutical equivalence and (ii) equivalence with respect to the efficacy of topical semisolids. The proposed corrective measures are disclosed and critically discussed, as they span from mere demands to widen the acceptance range (e.g., from ±10% to ±20%/±25% for rheology and in vitro release parameters highly prone to batch-to-batch variability) or reassess the optimal number of samples required to reach the desired statistical power, but also rely on specific data modeling or novel statistical approaches.

scholarly journals The Topical Nanodelivery of Vismodegib Enhances Its Skin Penetration and Performance In Vitro While Reducing Its Toxicity In Vivo

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 186
Author(s):  
Maria Natalia Calienni ◽  
Daniela Maza Vega ◽  
C. Facundo Temprana ◽  
María Cecilia Izquierdo ◽  
David E. Ybarra ◽  
...  
Keyword(s):  
Side Effects ◽  
Water Solubility ◽  
Polymeric Micelles ◽  
Skin Penetration ◽  
Distribution Volume ◽  
And Performance ◽  
Oral Doses ◽  
Advanced Basal Cell Carcinoma

Vismodegib is a first-in-class inhibitor for advanced basal cell carcinoma treatment. Its daily oral doses present a high distribution volume and several side effects. We evaluated its skin penetration loaded in diverse nanosystems as potential strategies to reduce side effects and drug quantities. Ultradeformable liposomes, ethosomes, colloidal liquid crystals, and dendrimers were able to transport Vismodegib to deep skin layers, while polymeric micelles failed at this. As lipidic systems were the most effective, we assessed the in vitro and in vivo toxicity of Vismodegib-loaded ultradeformable liposomes, apoptosis, and cellular uptake. Vismodegib emerges as a versatile drug that can be loaded in several delivery systems for topical application. These findings may be also useful for the consideration of topical delivery of other drugs with a low water solubility.

scholarly journals Natural variation in plant telomere length is associated with flowering time

2021 ◽  
Author(s):  
Jae Young Choi ◽  
Liliia R Abdulkina ◽  
Jun Yin ◽  
Inna B Chastukhina ◽  
John T Lovell ◽  
...  
Keyword(s):  
Life History ◽  
Telomere Length ◽  
Flowering Time ◽  
Dna Sequences ◽  
Genome Wide Association Study ◽  
Genomic Analysis ◽  
Life History Strategies ◽  
Length Variation ◽  
Chromosomal Structure ◽  
Chromosome Integrity

Abstract Telomeres are highly repetitive DNA sequences found at the ends of chromosomes that protect the chromosomes from deterioration during cell division. Here, using whole genome re-sequencing and terminal restriction fragment assays, we found substantial natural intraspecific variation in telomere length in Arabidopsis thaliana, rice (Oryza sativa), and maize (Zea mays). Genome-wide association study (GWAS) mapping in A. thaliana identified 13 regions with GWAS-significant associations underlying telomere length variation, including a region that harbors the telomerase reverse transcriptase (TERT) gene. Population genomic analysis provided evidence for a selective sweep at the TERT region associated with longer telomeres. We found that telomere length is negatively correlated with flowering time variation not only in A. thaliana, but also in maize and rice, indicating a link between life history traits and chromosome integrity. Our results point to several possible reasons for this correlation, including the possibility that longer telomeres may be more adaptive in plants that have faster developmental rates (and therefore flower earlier). Our work suggests that chromosomal structure itself might be an adaptive trait associated with plant life history strategies.

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