Physiology of Larval Feeding

2018 ◽  
Keyword(s):  
Growth And Development ◽  
Marine Invertebrate ◽  
Larval Growth ◽  
Circulatory System ◽  
Future Research ◽  
Larval Feeding ◽  
Digestive Physiology ◽  
Larval Body ◽  
The Individual ◽  
Invertebrate Larvae

The functional properties of marine invertebrate larvae represent the sum of the physiological activities of the individual, the interdependence among cells making up the whole, and the correct positioning of cells within the larval body. This chapter examines physiological aspects of nutrient acquisition, digestion, assimilation, and distribution within invertebrate larvae from an organismic and comparative perspective. Growth and development of larvae obviously require the acquisition of “food.” Yet the mechanisms where particulate or dissolved organic materials are converted into biomass and promote development of larvae differ and are variably known among groups. Differences in the physiology of the digestive system (secreted enzymes, gut transit time, and assimilation) within and among feeding larvae suggest the possibility of an underappreciated plasticity of digestive physiology. How the ingestion of seawater by and the existence of a circulatory system within larvae contribute to larval growth and development represent important topics for future research.

Consequences of natural variation in maternal investment and larval nutrition on larval growth of a marine polychaete

2007 ◽  
Vol 58 (11) ◽  
pp. 1002 ◽  
Author(s):  
Benjamin L. Smith ◽  
Toby F. Bolton
Keyword(s):  
Growth And Development ◽  
Developmental Stages ◽  
Marine Invertebrates ◽  
Marine Invertebrate ◽  
Larval Growth ◽  
Maternal Investment ◽  
Planktonic Food ◽  
Ambient Concentrations ◽  
Marine Polychaete ◽  
Invertebrate Larvae

Growth rates and planktonic development periods of marine invertebrate larvae have important consequences for the ecology of marine invertebrates. The growth and development of the larvae of a common southern Australian polychaete was examined to determine whether it was limited by natural concentrations of planktonic food, and whether naturally occurring variation in maternal investment in offspring influenced larval growth and development. Larvae that were provided concentrated diets of natural planktonic food were larger than larvae that were provided with food at ambient concentrations, but both experimental groups of larvae reached developmental stages immediately preceding settlement at the same time. Thus, larval growth was limited at natural concentrations of planktonic food but larval development rates were unaffected. These trends were also apparent in larvae fed with different concentrations of laboratory cultured food. Maternal investment in offspring (eggs) was higher on average for larger females than for smaller females. Larvae developing from smaller eggs were also smaller before settlement than larvae developing from larger eggs. Both maternal investment in offspring and the extent to which larval growth is food limited may vary spatially and seasonally along the southern coastline of Australia owing to the yearly occurrence of nutrient-rich oceanographic upwellings.

Effects of Environmental Conditions on Larval Growth and Development

2020 ◽  
pp. 195-222 ◽  
Author(s):  
Chaoshu Zeng ◽  
Guiomar Rotllant ◽  
Luis Giménez ◽  
Nicholas Romano
Keyword(s):  
Environmental Factors ◽  
Environmental Conditions ◽  
Growth And Development ◽  
Synergistic Effects ◽  
Larval Growth ◽  
Future Research ◽  
Physical Parameters ◽  
Aquatic Environments ◽  
In The Wild ◽  
Future Research Directions

The vast majority of crustaceans are aquatic, living in either marine or freshwater environments. Marine crustaceans—such as copepods, in particular—are ubiquitous in the oceans and perhaps the most numerous metazoans on Earth. Because crustaceans occur in all marine habitats, their larvae are exposed to highly diverse and sometimes variable environmental conditions, including extreme situations in which various environmental factors exert significant effects on larval growth and development. This chapter first describes the effects of food availability on crustacean larvae. Food paucity is a commonly occurring scenario in the wild, which can directly affect larval growth and development and, in severe cases, results in mortality. In the subsequent sections, we cover the effects of temperature and salinity—the two most prominent physical parameters in the aquatic environments—on growth and development of crustacean larvae. We then discuss the influence of other important physicochemical factors in aquatic environments on larval growth and development, including dissolved oxygen, light, ocean acidification, and pollutants. Finally, the last two sections of this chapter discuss synergistic effects of different environmental factors and suggest future research directions in this field.

Phenotypic Plasticity of Feeding Structures in Marine Invertebrate Larvae

2018 ◽  
Keyword(s):  
Phenotypic Plasticity ◽  
Molecular Mechanisms ◽  
Sea Urchins ◽  
Marine Invertebrate ◽  
Future Research ◽  
Trade Offs ◽  
Feeding Structure ◽  
Research Findings ◽  
Planktotrophic Larvae ◽  
Invertebrate Larvae

Nearly three decades ago, biologists discovered that planktotrophic larvae of sea urchins can alter the size of their ciliated feeding structures in response to the concentration of food (i.e., unicellular algae). In the years since, this response has become one of the best-studied examples of phenotypic plasticity in marine organisms. Researchers have found that this form of plasticity occurs widely among different types of feeding larvae in several phyla, and involves energetic trade-offs with a suite of correlated life history characters. Furthermore, investigators have recently started to unravel the genetic and molecular mechanisms underlying this plasticity. We review the literature on feeding-structure plasticity in marine invertebrate larvae. We highlight the diversity of species and variety of experimental designs and statistical methodologies, summarize research findings to draw more general conclusions, and target promising directions for future research.

Development of a German-Language Questionnaire to Measure Collective Orientation as an Individual Attitude

2017 ◽  
Vol 76 (3) ◽  
pp. 91-105 ◽  
Author(s):  
Vera Hagemann
Keyword(s):  
Team Performance ◽  
Reliability And Validity ◽  
Future Research ◽  
German Language ◽  
Team Members ◽  
Collective Orientation ◽  
Team Research ◽  
German Speaking ◽  
Individual Variables ◽  
The Individual

Abstract. The individual attitudes of every single team member are important for team performance. Studies show that each team member’s collective orientation – that is, propensity to work in a collective manner in team settings – enhances the team’s interdependent teamwork. In the German-speaking countries, there was previously no instrument to measure collective orientation. So, I developed and validated a German-language instrument to measure collective orientation. In three studies (N = 1028), I tested the validity of the instrument in terms of its internal structure and relationships with other variables. The results confirm the reliability and validity of the instrument. The instrument also predicts team performance in terms of interdependent teamwork. I discuss differences in established individual variables in team research and the role of collective orientation in teams. In future research, the instrument can be applied to diagnose teamwork deficiencies and evaluate interventions for developing team members’ collective orientation.

Academic Events: An Empirically Grounded Typology and Their Academic Impact

2020 ◽  
Vol 24 (4) ◽  
pp. 481-497 ◽  
Author(s):  
Thomas Trøst Hansen ◽  
David Budtz Pedersen ◽  
Carmel Foley
Keyword(s):  
Analytical Framework ◽  
Future Research ◽  
Academic Impact ◽  
Future Research Agenda ◽  
Tourism Studies ◽  
Academic Events ◽  
Business Events ◽  
The Individual ◽  
Analytical Frameworks ◽  
Academic Sector

The meetings industry, government bodies, and scholars within tourism studies have identified the need to understand the broader impact of business events. To succeed in this endeavor, we consider it necessary to develop analytical frameworks that are sensitive to the particularities of the analyzed event, sector, and stakeholder group. In this article we focus on the academic sector and offer two connected analyses. First is an empirically grounded typology of academic events. We identify four differentiating dimensions of academic events: size, academic focus, participants, and tradition, and based on these dimensions we develop a typology of academic events that includes: congress, specialty conference, symposium, and practitioners' meeting. Secondly, we outline the academic impact of attending these four types of events. For this purpose, the concept of credibility cycles is used as an analytical framework for examining academic impact. We suggest that academic events should be conceptualized and evaluated as open marketplaces that facilitate conversion of credibility. Data were obtained from interviews with 22 researchers at three Danish universities. The study concludes that there are significant differences between the events in terms of their academic impact. Moreover, the outcome for the individual scholar depends on the investment being made. Finally, the study calls for a future research agenda on beyond tourism benefits based on interdisciplinary collaborations.

The Role of Normative Information in Judgments of Others

2019 ◽  
Author(s):  
Katherine H. Rogers
Keyword(s):  
Social Desirability ◽  
Interpersonal Perception ◽  
Future Research ◽  
Average Person ◽  
The Individual ◽  
The Relationship ◽  
Source Of Information

When forming impressions of an other’s personality, people often rely on information not directly related to the individual at hand. One source of information that can influence people’s impressions of others is the personality of the average person (i.e., normative profile). This relationship between the normative profile and an impression is called normative accuracy or normativity. In this chapter, you will learn about the average personality, why it is important, the relationship to social desirability and what it means to have a normative impression, as well as correlates and moderators of normativity. More broadly, you will learn about current research and views regarding the normative profile and normative impressions as well as concrete steps for incorporating this approach into your future research on interpersonal perception.

scholarly journals Opportunities and Challenges of Green-Lean: An Integrated System for Sustainable Construction

2020 ◽  
Vol 12 (11) ◽  
pp. 4460 ◽  
Author(s):  
Mohammadsoroush Tafazzoli ◽  
Ehsan Mousavi ◽  
Sharareh Kermanshachi
Keyword(s):  
Cost Savings ◽  
Integrated Approach ◽  
Integrated System ◽  
Waste Minimization ◽  
Sustainable Construction ◽  
Future Research ◽  
Safety Improvement ◽  
The Individual ◽  
High Level ◽  
Industry Professionals

Although the two concepts of lean and sustainable construction have been developed due to different incentives, and they do not pursue the same exact goals, there exists considerable commonality between them. This paper discusses the potentials for integrating the two approaches and their practices and how the resulting synergy from combining the two methods can potentially lead to higher levels of fulfilling the individual goals of each of them. Some limitations and challenges to implementing the integrated approach are also discussed. Based on a comprehensive review of existing papers related to sustainable and lean construction topics, the commonality between the two approaches is discussed and grouped in five categories of (1) cost savings, (2) waste minimization, (3) Jobsite safety improvement, (4) reduced energy consumption, and (5) customers’ satisfaction improvement. The challenges of this integration are similarly identified and discussed in the four main categories of (1) additional initial costs to the project, (2) difficulty of providing specialized expertise, (3) contractors’ unwillingness to adopt the additional requirements, and (4) challenges to establish a high level of teamwork. Industry professionals were then interviewed to rank the elements in each of the two categories of opportunities and challenges. The results of the study highlight how future research can pursue the development of a new Green-Lean approach by investing in the communalities and meeting the challenges of this integration.

scholarly journals Validity of the Gender Dysphoria diagnosis and incidence trends in Sweden: a nationwide register study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malin Indremo ◽  
Richard White ◽  
Thomas Frisell ◽  
Sven Cnattingius ◽  
Alkistis Skalkidou ◽  
...  
Keyword(s):  
Gender Dysphoria ◽  
Age Groups ◽  
Medical Intervention ◽  
Future Research ◽  
Advantages And Disadvantages ◽  
Incidence Trends ◽  
Interaction Terms ◽  
Definition Of ◽  
The Individual ◽  
Nationwide Register Study

AbstractThe aim of this study was to examine the validity of the Gender Dysphoria (GD) diagnoses in the Swedish National Patient Register (NPR), to discuss different register-based definitions of GD and to investigate incidence trends. We collected data on all individuals with registered GD diagnoses between 2001 and 2016 as well as data on the coverage in the NPR. We regarded gender confirming medical intervention (GCMI) as one proxy for a clinically valid diagnosis and calculated the positive predictive value (PPV) for receiving GCMI for increasing number of registered GD diagnoses. We assessed crude and coverage-adjusted time trends of GD during 2004–2015 with a Poisson regression, using assigned sex and age as interaction terms. The PPV for receiving GCMI was 68% for ≥ 1 and 79% for ≥ 4 GD-diagnoses. The incidence of GD was on average 35% higher with the definition of ≥ 1 compared to the definition of ≥ 4 diagnoses. The incidence of GD, defined as ≥ 4 diagnoses increased significantly during the study period and mostly in the age categories 10–17 and 18–30 years, even after adjusting for register coverage. We concluded that the validity of a single ICD code denoting clinical GD in the Swedish NPR can be questioned. For future research, we propose to carefully weight the advantages and disadvantages of different register-based definitions according to the individual study’s needs, the time periods involved and the age-groups under study.

scholarly journals Testing the Role of Emotion Dysregulation as a Predictor of Juvenile Recidivism

2021 ◽  
Vol 11 (1) ◽  
pp. 83-95
Author(s):  
Kalin Z. Salinas ◽  
Amanda Venta
Keyword(s):  
Emotion Regulation ◽  
Juvenile Offenders ◽  
Emotion Dysregulation ◽  
Longitudinal Research ◽  
Future Research ◽  
Individual Factor ◽  
Treatment And Prevention ◽  
One Year ◽  
The Individual

The current study proposed to determine whether adolescent emotion regulation is predictive of the amount and type of crime committed by adolescent juvenile offenders. Despite evidence in the literature linking emotion regulation to behaviour problems and aggression across the lifespan, there is no prior longitudinal research examining the predictive role of emotion regulation on adolescent recidivism, nor data regarding how emotion regulation relates to the occurrence of specific types of crimes. Our primary hypothesis was that poor emotion regulation would positively and significantly predict re-offending among adolescents. We tested our hypothesis within a binary logistic framework utilizing the Pathways to Desistance longitudinal data. Exploratory bivariate analyses were conducted regarding emotion regulation and type of crime in the service of future hypothesis generation. Though the findings did not indicate a statistically significant relation between emotion regulation and reoffending, exploratory findings suggest that some types of crime may be more linked to emotion regulation than others. In sum, the present study aimed to examine a hypothesized relation between emotion regulation and juvenile delinquency by identifying how the individual factor of dysregulated emotion regulation may have played a role. This study’s findings did not provide evidence that emotion regulation was a significant predictor of recidivism over time but did suggest that emotion regulation is related to participation in certain types of crime one year later. Directions for future research that build upon the current study were described. Indeed, identifying emotion regulation as a predictor of adolescent crime has the potential to enhance current crime prevention efforts and clinical treatments for juvenile offenders; this is based on the large amount of treatment literature, which documents that emotion regulation is malleable through treatment and prevention programming.

Acquiring variable commands at home and abroad: Examining optatives and imperatives in L1 and L2 Spanish

2020 ◽  
Vol 13 (1) ◽  
pp. 79-113
Author(s):  
Farrah Neumann ◽  
Matthew Kanwit
Keyword(s):  
Second Language ◽  
Second Language Acquisition ◽  
Study Abroad ◽  
Language Teaching ◽  
Applied Linguistics ◽  
Future Research ◽  
Control Group ◽  
Before And After ◽  
The Individual ◽  
At Home

AbstractSince many linguistic structures are variable (i. e. conveyed by multiple forms), building a second-language grammar critically involves developing sociolinguistic competence (Canale and Swain. 1980. Theoretical bases of communicative approaches to second language teaching and testing. Applied Linguistics 1(1). 1–47), including knowledge of contexts in which to use one form over another (Bayley and Langman. 2004. Variation in the group and the individual: Evidence from second language acquisition. International Review of Applied Linguistics in Language Teaching 42(4). 303–318). Consequently, researchers interested in such competence have increasingly analyzed the study-abroad context to gauge learners’ ability to approximate local norms following a stay abroad, due to the quality and quantity of input to which learners may gain access (Lafford. 2006. The effects of study abroad vs. classroom contexts on Spanish SLA: Old assumptions, new insights and future research directions. In Carol Klee & Timothy Face (eds.), Selected proceedings of the 7th conference on the acquisition of Spanish and Portuguese as first and second languages, 1–25. Somerville, MA: Cascadilla Proceedings Project). Nevertheless, the present study is the first to examine native or learner variation between imperative (e. g. ven ‘come’) and optative Spanish commands (e. g. que vengas ‘come’). We first performed a corpus analysis to determine the linguistic factors to manipulate in a contextualized task, which elicited commands from learners before and after four weeks abroad in Alcalá de Henares, Spain. Their overall rates of selection and predictive factors were compared to local native speakers (NSs) and a control group of at-home learners.Results revealed that the abroad learners more closely approached NS rates of selection following the stay abroad. Nonetheless, for both learner groups conditioning by independent variables only partially approximated the NS system, which was more complex than previously suggested.

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