Particle retention during respiration and particulate feeding in the suspension-feeding blackfish, Orthodon microlepidotus

1995 ◽  
Vol 52 (12) ◽  
pp. 2534-2542 ◽  
Author(s):  
S. Laurie Sanderson ◽  
Joseph J. Cech Jr.
Keyword(s):  
Interindividual Variability ◽  
Ventilation Rate ◽  
Retention Rates ◽  
Interindividual Variation ◽  
Suspension Feeding ◽  
Volume Ventilation ◽  
Particle Retention ◽  
Particulate Feeding ◽  
Plankton Communities ◽  
Number Of Particles

Juvenile blackfish (Orthodon microlepidotus) retained styrene microspheres (30–90 μm) during respiration in the absence of food. The fish retained significantly more microspheres when particulate feeding on Artemia adults, suspension feeding on Artemia nauplii, or in the presence of Artemia extract than when respiring in the absence of food. The frequency distribution of microsphere sizes retained during respiration did not differ significantly from that retained during feeding, a result that is consistent with the hypothesis that the site and method of particle retention during respiration and particulate feeding do not differ from those operating during suspension feeding. There was significant interindividual variability in the number of particles retained. Some individuals retained consistently fewer microspheres than other individuals of similar size and age, suggesting that further study is needed to quantify interindividual variation in other factors (e.g., stroke volume, ventilation rate, or mucus secretion) that have the potential to affect particle retention rates. Our results have implications for the energetics of suspension-feeding fishes, the impacts of suspension-feeding fishes on plankton communities, and the exposure of these fishes to toxic phytoplankton strains and particle-bound organic chemicals.

scholarly journals Hypothalamus volume and fatherhood: similarity across men and interindividual differences among dads

2020 ◽  
Author(s):  
Madison Long ◽  
Lara Puhlmann ◽  
Pascal Vrticka
Keyword(s):  
Attachment Style ◽  
Interindividual Variability ◽  
Brain Area ◽  
Self Report ◽  
Interindividual Variation ◽  
Interindividual Differences ◽  
Child Relationship ◽  
Male Caregivers ◽  
Mother Child Relationship ◽  
Do So

Most studies on mammalian caregiving and attachment have focused on the mother-child relationship, particularly in humans. Yet, recent re-considerations of attachment theory and changing societal roles of male caregivers have highlighted the necessity for research with fathers. In this pre-registered study (https://aspredicted.org/5uj5y.pdf), we examined the structure of the hypothalamus – an important subcortical brain area for caregiving and attachment behavior – in a sample of N=95 fathering (child age 5-6 years) and non-fathering men. To do so, we used a recently developed technique to accurately and efficiently identify the human hypothalamus in 3T MRI and calculate hypothalamus volume. Furthermore, we employed several self-report measures to assess interindividual differences in attachment style across all men, and caregiving specifically in fathers. While we found no difference in hypothalamus volume between fathers and non-fathers, fathers' interindividual variation in caregiving style was related to hypothalamus volume. Specifically, we observed that fathers who held greater belief in the importance of their role as a father and reported more enjoyment of interacting with their child had greater total hypothalamus volume. This finding suggests that there is interindividual variability in the association between brain structure and caregiving style in fathers, warranting further research.

Particle retention by non-suspension-feeding cyprinid fishes

1998 ◽  
Vol 55 (4) ◽  
pp. 861-868 ◽  
Author(s):  
S Laurie Sanderson ◽  
Mark E Mort ◽  
Joseph J Cech, Jr.
Keyword(s):  
Fish Species ◽  
Brine Shrimp ◽  
Morphological Features ◽  
Body Volume ◽  
Suspension Feeding ◽  
Gill Rakers ◽  
Particle Retention ◽  
Ptychocheilus Grandis ◽  
Cyprinid Fishes ◽  
Brine Shrimp Cysts

Insectivorous Sacramento squawfish (Ptychocheilus grandis) and omnivorous benthic-feeding California roach (Hesperoleucus symmetricus) were exposed to suspended styrene microspheres (31-90 µm) or brine shrimp cysts (210-300 µm) in the presence of finely crushed Tetramin flakes or adult Artemia. These fish species retained small numbers of microspheres, and significantly more brine shrimp cysts than microspheres. During a 10-min period, they swallowed all of the brine shrimp cysts from a volume of water equivalent to 1-15 times their body volume. Squawfish and roach do not possess the morphological features of the branchial apparatus and palate that are associated with suspension feeding in confamilial Sacramento blackfish (Orthodon microlepidotus). The brine shrimp cysts could have been trapped between squawfish and roach gill rakers, while the microspheres as well as the brine shrimp cysts could have been retained on mucus-covered buccopharyngeal surfaces. These results suggest that non-suspension-feeding fish species may ingest small suspended particles routinely, with energetic and ecotoxicological implications that deserve further study.

scholarly journals Particle retention in suspension-feeding fish after removal of filtration structures

Zoology ◽  
2013 ◽  
Vol 116 (6) ◽  
pp. 348-355 ◽  
Author(s):  
Jennifer C. Smith ◽  
S. Laurie Sanderson
Keyword(s):  
Suspension Feeding ◽  
Particle Retention

scholarly journals Cerebral Glucose Transport Implies Individualized Glial Cell Function

2001 ◽  
Vol 21 (10) ◽  
pp. 1160-1170 ◽  
Author(s):  
Ludwig E. Feinendegen ◽  
Hans Herzog ◽  
Keith H. Thompson
Keyword(s):  
Glial Cell ◽  
Glucose Transport ◽  
Grey Matter ◽  
Cell Function ◽  
Interindividual Variability ◽  
Interindividual Variation ◽  
Glucose Levels ◽  
Positron Emission ◽  
Fitting Procedures ◽  
Two Parameters

Previous positron emission tomography (PET) measurements of cerebral glucose transport using [11C]-3-O-methylglucose (CMG) suggested an interindividual variation in the values of the rate constant of tracer outflow (k2) larger than that for the clearance rate of inflow (K1). These two parameters were examined in healthy cerebral cortex by dynamic PET in 4 men and 2 women (aged 24 to 73 years) without neurologic disease, and in 1 man (42 years) with a recent left hemispheric cerebral infarction under normoglycemia (average blood plasma d-glucose concentration, 5.44 ± 1.94 μmol/mL) and again under hyperglycemia (average, 10.24 ± 1.44 μmol/mL). Time-radioactivity curves were obtained from healthy cortex (grey matter) and plasma and analyzed for the values of K1 and k2 by two graphical approaches and two fitting procedures. Both K1 and k2 significantly declined with increasing plasma glucose levels. A highly significant interindividual but not intraindividual variability for k2 was found at normoglycemia and hyperglycemia. The interindividual variability of K1, although borderline significant, was less than that of k2. Accordingly variable were the distribution volumes K1 /k2. These data suggest individualized glial cell function and may be relevant to pathogenesis of neuropsychiatric disease.

Efficiency of particle retention in 13 species of suspension feeding bivalves

Ophelia ◽  
1978 ◽  
Vol 17 (2) ◽  
pp. 239-246 ◽  
Author(s):  
Flemming Møhlenberg ◽  
Hans Ulrik Riisgård
Keyword(s):  
Suspension Feeding ◽  
Particle Retention

Horizontal and vertical distribution patterns, retention rates, and population dynamics of zooplankton on Western Bank, Scotian Shelf

2003 ◽  
Vol 60 (10) ◽  
pp. 1229-1244 ◽  
Author(s):  
Christian S Reiss ◽  
Ian A McLaren ◽  
Patricia Avendaño
Keyword(s):  
Population Dynamics ◽  
Vertical Distribution ◽  
Spatial Scales ◽  
Distribution Patterns ◽  
Zooplankton Biomass ◽  
Retention Rates ◽  
Local Production ◽  
Scotian Shelf ◽  
Particle Retention ◽  
Horizontal And Vertical Distribution

We assess the importance of retention rates and local production to the concentration of zooplankton on Western Bank, Scotian Shelf, during September and October 1998. We do so using (i) particle retention rates derived from an array of 25 current meters and inferences from hydrographic structure; (ii) observations on the horizontal and vertical distribution of zooplankton and ichthyoplankton; and (iii) a simple projection-matrix model of the population dynamics of two copepod species, Centropages typicus and Pseudocalanus spp. Zooplankton biomass and adult stages of copepods were more abundant in surface waters on the bank (p < 0.05) at broad (25 km) spatial scales. Zooplankton was correlated with ichthyoplankton abundance at this scale (r > 0.5, p < 0.001), a result of local production of both zooplankton and fish on the bank. The time-dependent anticyclonic circulation around Western Bank was variable, and particle retention rates were 18 and 33% for 20 days at 12.5 and 28.5 m, respectively. The population model showed that both C. typicus and Pseudocalanus spp. are capable of increasing their population size despite advective loss and mortality rates approaching 10%·day-1. We conclude that local production exceeding advective loss rates can explain the high concentrations of zooplankton on Western Bank.

scholarly journals Sequence features of retrotransposons allow for epigenetic variability

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kevin R Costello ◽  
Amy Leung ◽  
Candi Trac ◽  
Michael Lee ◽  
Mudaser Basam ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Interindividual Variability ◽  
Large Fraction ◽  
Cpg Islands ◽  
Interindividual Variation ◽  
Potential Mechanism ◽  
Epigenetic Variability ◽  
Genomic Context ◽  
Mammalian Genomes ◽  
Intracisternal A Particle

Transposable elements (TEs) are mobile genetic elements that make up a large fraction of mammalian genomes. While select TEs have been co-opted in host genomes to have function, the majority of these elements are epigenetically silenced by DNA methylation in somatic cells. However, some TEs in mice, including the Intracisternal A-particle (IAP) subfamily of retrotransposons, have been shown to display interindividual variation in DNA methylation. Recent work has revealed that IAP sequence differences and strain-specific KRAB zinc finger proteins (KZFPs) may influence the methylation state of these IAPs. However, the mechanisms underlying the establishment and maintenance of interindividual variability in DNA methylation still remain unclear. Here we report that sequence content and genomic context influence the likelihood that IAPs become variably methylated. IAPs that differ from consensus IAP sequences have altered KZFP recruitment that can lead to decreased KAP1 recruitment when in proximity of constitutively expressed genes. These variably methylated loci have a high CpG density, similar to CpG islands, and can be bound by ZF-CxxC proteins, providing a potential mechanism to maintain this permissive chromatin environment and protect from DNA methylation. These observations indicate that variably methylated IAPs escape silencing through both attenuation of KZFP binding and recognition by ZF-CxxC proteins to maintain a hypomethylated state.

scholarly journals Preliminary investigation into the ventilatory effects of midazolam in isoflurane-anaesthetised goats

2012 ◽  
Vol 83 (1) ◽  
Author(s):  
George F. Stegmann ◽  
Lynette Bester
Keyword(s):  
Tidal Volume ◽  
Repeated Measures ◽  
Preliminary Investigation ◽  
Face Mask ◽  
Ventilation Rate ◽  
Carbon Dioxide Partial Pressure ◽  
Volume Ventilation ◽  
Ventilatory Effects ◽  
End Tidal ◽  
Cuffed Tracheal Tube

The ventilatory effects of intravenous midazolam (MDZ) were evaluated in isoflurane- anaesthetised goats. Eight female goats aged 2–3 years were fasted from food and water for 12 h. Anaesthesia was then induced using a face mask with isoflurane in oxygen, whilst the trachea was intubated with a cuffed tracheal tube and anaesthesia maintained with isoflurane at 1.5% end-tidal concentration. Ventilation was spontaneous. The goats were treated with either a saline placebo (PLC) or MDZ intravenously at 0.2 mg/kg. Analysis of variance for repeated measures was used for the analysis of data. Significance was taken at the 0.05 level. Differences between treatments were not statistically significant (p > 0.05) for tidal volume, ventilation rate, tidal volume/kg (VT/kg) and end-tidal carbon dioxide partial pressure. Within treatments, VT and VT/kg differed 5 min after MDZ administration; this was statistically significant (p < 0.05). The occurrence of apnoea in the MDZ-treated goats was statistically significant (p = 0.04) compared with the PLC treated goats. Intravenous MDZ at 0.2 mg/kg administered to isoflurane-anaesthetised goats may result in transient apnoea and a mild decrease in VT and VT/kg.

scholarly journals Foods Contributing to Macronutrient Intake of Women Living in Puerto Rico Reflect Both Traditional Puerto Rican and Western-Type Diets

Nutrients ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1242 ◽  
Author(s):  
Emily Truesdell ◽  
Michelle Schelske-Santos ◽  
Cruz Nazario ◽  
Rosa Rosario-Rosado ◽  
Susan McCann ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Chronic Disease ◽  
Dietary Intake ◽  
Puerto Rican ◽  
Interindividual Variability ◽  
Interindividual Variation ◽  
Food Sources ◽  
White Bread ◽  
Macronutrient Intake ◽  
Puerto Rican Women

Lack of variability in dietary intake within a population makes identification of relationships between diet and disease difficult. Studies in populations with greater interindividual variation can provide important insights. The Puerto Rican diet is in transition from a traditional to a more Western-type diet, resulting in greater interindividual variability. We identified foods contributing to absolute intake and variability in the intake of macronutrients among Puerto Rican women. One hundred women, aged 30–79, residents of San Juan, Puerto Rico, completed three, interviewer-administered, 24-h dietary recalls from which foods contributing to absolute intake and intake variability in intake of energy, fat, protein, carbohydrate and dietary fiber were determined. The overall prevalence of intake of foods was also calculated. Traditional Puerto Rican foods such as legumes, rice, and plantains were important contributors to the intake of calories and macronutrients as were foods more typical of Western diets including white bread and sweetened carbonated beverages. Identification of food sources of nutrients for this population with a diet in transition can contribute to the development of instruments to measure dietary intake and to understand the contribution of diet to the etiology of chronic disease among Puerto Rican women.

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