Effects of Aluminum on the Leopard Frog, Rana pipiens: Life Stag Comparisons and Aluminum Uptake

1990 ◽  
Vol 47 (1) ◽  
pp. 210-216 ◽  
Author(s):  
Joseph Freda ◽  
D. Gordon McDonald
Keyword(s):  
Rana Pipiens ◽  
Low Ph ◽  
The Body ◽  
Leopard Frog ◽  
Whole Body ◽  
Toxicity Tests ◽  
Al Content ◽  
Wide Range ◽  
Water Ph ◽  
Percent Mortality

In this study, we conducted a series of toxicity tests investigating the response of embryos, prestage 25 tadpoles and 3-wk old tadpoles of the leopard frog (Rana pipiens) to a wide range pf pH (4.2–4.8) and Al (0–1000 μg∙:L−1}, and to pH 6.5 with no Al present. In embryos and prestage 25 tadpoles, Al ameliorated the toxic effects of very low pH's (4.2–4.4), while becoming toxic at higher pH's (4.6–4.8). Although both embryos and prestage 25 tadpoles were killed by low pH (pH 4.2–4.4 and 4.2, respectively) and elevated Al ([Formula: see text] and [Formula: see text] Al, respectively), embryos were relatively more sensitive (i.e. higher percent mortality) to low pH, whereas prestage 25 tadpoles were relatively more sensitive to Al Three week old tadpoles did not die at any test pH (without Al) and mortality (>20%) caused by Al occurred at only pH 4.8 and 750–1000 μg∙L−1 Al. The body sodium concentrations of 3-wk old tadpoles that survived high Al exposure were depressed indicating sublethal stress. Whole body Al uptake in 3-wk old tadpoles was also elevated in water containing high concentrations of Al, but it was positively related to water pH and exposure time. This result suggests that body Al content is not an accurate indicator of Al exposure in tadpoles living in acidic, Al contaminated ponds.

Hierarchical Engineering Model of the Human Body

2016 ◽  
Author(s):  
Somayajulu D. Karamchetty
Keyword(s):  
Human Body ◽  
Hierarchical Modeling ◽  
Control Volume ◽  
The Body ◽  
Whole Body ◽  
Operational Parameters ◽  
Sufficient Detail ◽  
Wide Range ◽  
Level Model ◽  
Complex Engineering

Engineers and scientists are able to understand and analyze the behavior of complex engineering systems in a wide range of critical technologies through hierarchical modeling followed by simulation of the model operation. This process results in a high fidelity integrated model as each level in the hierarchy is modeled in sufficient detail. The overall objective of this effort is to develop a sophisticated hierarchical model of the human body, followed by simulation of the model operation. In this initial research phase, the feasibility of the concept is explored and a framework for the model is described. A six-level model consisting of the whole body as a system, system of systems, organs, tissues, cells, and molecules is proposed and described. This paper explains that the human body is amenable to such hierarchical modeling and describes the benefits that can be achieved. The systems in the body deal with numerous processes: electrical, chemical, biochemical, energy conversion, transportation, pumping, sensing, communications, and so on. Control volume models for the organs in the body capture the mass and energy balance and chemical reactions. Tissue can be represented similar to structural components made of various biomaterials. Cells can be represented as a manufacturing and maintenance workforce assisted by molecular reactions. Following the representation of a healthy body, simulation runs by inserting faults and/or deficiencies in the operational parameters into the model could reveal the causes for specific diseases and illnesses. Such modeling and simulation will benefit medical, pharmaceutical, nutritional specialists, and engineers in designing, developing, and delivering products and services to enable humans to lead healthy lives.

scholarly journals Sociality and Interaction Envelope Organize Visual Action Representations

2019 ◽  
Author(s):  
Leyla Tarhan ◽  
Talia Konkle
Keyword(s):  
Visual Cortex ◽  
Large Scale ◽  
Functional Neuroimaging ◽  
Action Observation ◽  
The Body ◽  
Whole Body ◽  
Action Perception ◽  
Social Content ◽  
Wide Range ◽  
The Brain

Humans observe a wide range of actions in their surroundings. How is the visual cortex organized to process this diverse input? Using functional neuroimaging, we measured brain responses while participants viewed short videos of everyday actions, then probed the structure in these responses using voxel-wise encoding modeling. Responses were well fit by feature spaces that capture the body parts involved in an action and the action’s targets (i.e. whether the action was directed at an object, another person, the actor, and space). Clustering analyses revealed five large-scale networks that summarized the voxel tuning: one related to social aspects of an action, and four related to the scale of the interaction envelope, ranging from fine-scale manipulations directed at objects, to large-scale whole-body movements directed at distant locations. We propose that these networks reveal the major representational joints in how actions are processed by visual regions of the brain.Significance StatementHow does the brain perceive other people’s actions? Prior work has established that much of the visual cortex is active when observing others’ actions. However, this activity reflects a wide range of processes, from identifying a movement’s direction to recognizing its social content. We investigated how these diverse processes are organized within the visual cortex. We found that five networks respond during action observation: one that is involved in processing actions’ social content, and four that are involved in processing agent-object interactions and the scale of the effect that these actions have on the world (its “interaction envelope”). Based on these findings, we propose that sociality and interaction envelope size are two of the major features that organize action perception in the visual cortex.

A study of field drain ochre deposits. 2. The distribution of micro-organisms

1987 ◽  
Vol 108 (2) ◽  
pp. 347-351 ◽  
Author(s):  
I. Ap Dbwi ◽  
D. B. Johnson ◽  
W. I. Kelso
Keyword(s):  
Thiobacillus Ferrooxidans ◽  
Heterotrophic Bacteria ◽  
Drainage Water ◽  
Low Ph ◽  
Filamentous Bacteria ◽  
England And Wales ◽  
Neutral Ph ◽  
Wide Range ◽  
Water Ph ◽  
Micro Organisms

SummarySheathed filamentous bacteria,Leptothrixspp. andGallionellaspp., were observed in ochre samples from sites in England and Wales.Thiobacillus ferrooxidanswas found in acidic samples (pH < 4·0) and in ochre from drainage water of near neutral pH suggesting that it can contribute to ochre formation over a wide range of drainage water pH, Heterotrophic bacteria capable of growing in artificial media of low pH and complexdegrading heterotrophic bacteria were also isolated. Some ochre deposits could be described as either pyritic or filamentous but the majority of samples fell between these extremes and had various combinations ofT. ferrooxidans, sheathed filamentous bacteria and other heterotrophic bacteria.

Quantitative Whole Body Autoradiography (QWBA) Analysis Reveals That CPX-351 Shifts the Exposure of Cytarabine (Cyt) and Daunorubicin (Daun) Away from Many Tissues While Providing Prolonged Exposure to Cytotoxic Drug Concentrations in the Bone Marrow Compared to Conventional Free Drug Administration

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3740-3740
Author(s):  
Lawrence D Mayer ◽  
Nicole Sadowski ◽  
Paul Tardi ◽  
Xiaowei Xie ◽  
Donna Cabral-Lilly ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Tissue Distribution ◽  
Drug Exposure ◽  
The Body ◽  
Whole Body ◽  
Molar Ratio ◽  
Employment Equity ◽  
Drug Concentrations ◽  
Wide Range ◽  
Equity Ownership

Abstract Background: CPX-351 is a liposomal formulation co-encapsulating Cyt and Daun, that delivers the drugs in vivo at a 5:1 molar ratio shown to be synergistic preclinically. Clinically, CPX-351 has provided evidence of promising improvements in patient outcomes, most notably in elderly newly diagnosed high risk (secondary) AML and in unfavorable risk first relapse adult AML where statistically significant increases in overall survival where observed in two randomized, controlled Phase 2 studies. In patients, CPX-351 displays a volume of distribution equal to the plasma volume and first order elimination with a half-life of > 24h for both drugs while maintaining the circulating Cyt:Daun molar ratio near 5:1. This is in contrast to the two drugs as conventionally administered in non-liposomal (NL) aqueous solution form where very rapid drug elimination is observed. Comparison of tissue distribution over time between CPX-351 and NL Cyt:Daun was performed in rats to better understand the pharmacodynamic relationships for CPX-351 in the context of what is known for the non-liposomal (NL) drugs, particularly as it relates to tissues relevant to efficacy and drug toxicity. Methods: Duplicate batches utilizing either [14C]Daun or [14C]Cyt CPX-351 or saline solutions of like labeled Cyt+Daun were prepared. Long-Evans rats received single IV bolus doses of either 15 units/kg (15 mg/kg Cyt + 6.64 mg/kg Daun) CPX-351, or a saline solution of 300 mg/kg Cyt + 10 mg/kg Daun. These doses were selected based on allometric scaling to reflect the respective clinical doses of CPX-351 and non-infusional Cyt:Daun treatment regimens. Animals were sacrificed at the designated time points post-dose and were frozen in a dry-ice/hexane bath in preparation for QWBA procedures. The tissue distribution of test article-derived radioactivity was determined using QWBA. Exposure of Cyt and Daun to a wide range of tissues was estimated based on the tissue density of [14C]Cyt-derived or [14C]Daun-derived radioactivity from QWBA section images. Tissue drug exposure comparisons between CPX-351 and NL Cyt:Daun were performed using Cmax and AUC0-t values. Results: The rapid tissue distribution of Cyt and Daun following injection of the NL form of the combination was reflected by the recovery of <5% of either drug in the plasma 15 minutes after injection and tissue/plasma AUC0-t ratios that were >1 and >10 for [14C]Cyt and [14C]Daun, respectively, for the majority of tissues studied. In contrast, for CPX-351 virtually all of the injected Cyt and Daun was present in the plasma between 0.25-1.0 hours and corresponding tissue/plasma AUC0-t ratios in the majority of tissues were <0.05 and <0.2 for [14C]Cyt and [14C]Daun, respectively. These differences were readily apparent in the QWBA section images. For the NL form of the combination, [14C]Cyt and [14C]Daun were widely distributed throughout the body shortly after injection. Following CPX-351 administration, radioactivity was more limited to discreet tissues and organs. Distribution of Cyt into tissues after CPX-351 administration was reduced as well as much slower than after NL Cyt injection as reflected by markedly lower Cmax values in all non-vascular tissues as well as lower AUC values in a majority of tissues. Comparing [14C]Daun distribution for CPX-351 vs NL Daun revealed a slower removal from the blood/plasma compartment and gradual distribution to tissues for CPX-351 with a similar general tissue profile as for NL drug with the notable increases in exposure to spleen, liver, testis and bone marrow. Bone marrow levels of Cyt and Daun peaked at 24h post CPX-351 injection and persisted for several days at anti-leukemic concentrations; drug levels present in the marrow at 96h were well above the CPX-351 IC50 values previously observed with fresh AML patient blast samples. In contrast, bone marrow Cyt concentrations fell below detectable limits within 24h after administration of NL drug. Conclusions: CPX-351 shifts the exposure of Cyt and Daun away from most non-hematologic tissues compared to NL drug treatment. Importantly, CPX-351 accumulates and persists in the bone marrow for over 4 days at concentrations known to have anti-leukemic activity against AML blasts. Taken together, these results provide additional biologic rationale that support the clinical improvements in both efficacy and safety seen for CPX-351 in randomized trials compared to conventional Cyt + Daun treatment. Disclosures Mayer: Celator: Employment, Equity Ownership, Patents & Royalties. Sadowski:Xenobiotic Laboratories: Employment. Tardi:Celator Pharmaceuticals: Employment, Equity Ownership. Xie:Celator Pharmaceuticals: Employment, Equity Ownership. Cabral-Lilly:Ceator Pharmaceuticals: Employment, Equity Ownership. Heller:Xenobiotic Laboratories: Employment, Research Funding.

In vivo n.m.r. imaging in medicine: the Aberdeen approach, both physical and biological

1980 ◽  
Vol 289 (1037) ◽  
pp. 519-533 ◽  
Keyword(s):  
Pulse Sequence ◽  
The Body ◽  
Spin Lattice Relaxation ◽  
Surrounding Tissue ◽  
Whole Body ◽  
Spin Concentration ◽  
Stage Of Development ◽  
Wide Range

A novel magnetic field and radio frequency (1.7 MHz) pulse sequence is described for a whole body n.m.r. imaging machine under construction. Selective excitation is used to obtain signals from successive lines of proton spins (water) across the body to build up an image of a transverse section. The images display spin concentration and spin-lattice relaxation time, T 1 , separately. For a 50 % change in T 1 to be discerned in the human trunk, a spatial resolution of 2 cm 3 is expected for a 2 min scan and 0.5 cm 3 for a 30 min scan. Very preliminary images at the present incomplete stage of development show the geometrical accuracy and T 1 discrimination: an in vivo image demonstrates some of the difficulties to be overcome. In vitro measurements of normal rabbit tissue samples have been made at 24 MHz to map the T 1 distributions that can be expected from normal subjects. The transposition of this information from rabbit to man, and from 24 MHz to 2.5 MHz have been checked and the comparison shown to be meaningful. Of pathological samples, human breast tumour and human liver metastases offer a good contrast to their surrounding tissue, and an experimental investigation has shown that tissue immediately surrounding a tumour also has an elevated T 1 value. A wide range of abnormalities that are associated with abnormal fluid formation in the body may be amenable to imaging by the n.m.r. technique. Potential hazards are believed to be small in the present generation of equipment.

Head Movements Produced During Whole Body Rotations and Their Sensitivity to Changes in Head Inertia in Squirrel Monkeys

2008 ◽  
Vol 99 (5) ◽  
pp. 2369-2382 ◽  
Author(s):  
J. S. Reynolds ◽  
G. T. Gdowski
Keyword(s):  
Head Movement ◽  
Muscle Activation ◽  
Human Subjects ◽  
Squirrel Monkeys ◽  
The Body ◽  
Head Movements ◽  
Whole Body ◽  
Movement Kinematics ◽  
Behavioral Studies ◽  
Wide Range

The head's inertia produces forces on the neck when the body moves. One collective function of the vestibulocollic and cervicocollic reflexes (VCR and CCR) is thought to be to stabilize the head with respect to the trunk during whole body movements. Little is known as to whether their head-movement kinematics produced by squirrel monkeys during whole body rotations are similar to those of cats and humans. Prior experiments with cats and human subjects have shown that yaw head-movement kinematics are unaffected by changes in the head's inertia when the whole body is rotated. These observations have led to the hypothesis that the combined actions of the VCR and CCR accommodate for changes in the head's inertia. To test this hypothesis in squirrel monkeys, it was imperative to first characterize the behavior of head movements produced during whole body rotation and then investigate their sensitivity to changes in the head's inertia. Our behavioral studies show that squirrel monkeys produce only small head movements with respect to the trunk during whole body rotations over a wide range of stimulus frequencies and velocities (0.5–4.0 Hz; 0–100°/s). Similar head movements were produced when only small additional changes in the head's inertia occurred. Electromyographic recordings from the splenius muscle revealed that an active process was utilized such that increases in muscle activation occurred when the inertia of the head was increased. These results are consistent with prior cat and human studies, suggesting that squirrel monkeys have a similar horizontal VCR and CCR.

scholarly journals A study of whole-body isotope dilution of [14C]ascorbic acid in guinea-pigs with graded ascorbate intakes

1992 ◽  
Vol 68 (3) ◽  
pp. 717-728 ◽  
Author(s):  
C. J. Bates ◽  
Harumi Tsuchiya ◽  
P. H. Evans
Keyword(s):  
Dietary Intake ◽  
Guinea Pigs ◽  
Specific Activity ◽  
The Body ◽  
Whole Body ◽  
Dietary Intakes ◽  
Radioactive Label ◽  
Wide Range ◽  
Specific Activities ◽  
The Individual

The purpose of the present study was first to assess the extent to which unlabelled ascorbate in the diet of guinea-pigs can exchange with labelled ascorbate within their organs when the dietary intake is varied over a wide range, and second to determine whether the retention of label might be used to assess either the amount of ascorbate intake or its biological availability where these are not known. The retention of [14C]ascorbate in the body and in various organs of guinea-pigs were, therefore, measured following a 13 d period of graded dietary intakes of ascorbate. It was found first, that the amount of label retained in each of the organs, 13 d after the initial dose of labelled ascorbate, was much more closely related to the amount of ascorbate intake after labelling than to the intake (and tissue ascorbate levels) before and at the time of labelling. Second, most of the individual internal organs exhibited a constant relationship between the specific activity at 13 d and the dietary intake, except for brain which was flushed to a smaller extent. Third, in agreement with several previous studies a high proportion of the radioactive label in the tissues was found to be still present in ascorbate. The specific activity of column-purified ascorbate was very similar to the estimated specific activity in the crude extract, which implies that it may be possible to estimate specific activities (or stable isotope enrichments) at certain sites without rigorous isolation procedures. Fourth, the amount of radioactivity appearing in the urine 2 d before killing the animals was correlated with the amount of ascorbate intake and with tissue specific activities, suggesting that intakes (or bioavailability) might be predicted from the patterns of label-appearance in the urine

Whole Body Ions of Brook Trout (Salvelinus fontinalis) Alevins: Responses of Yolk-Sac and Swim-Up Stages to Water Acidity, Calcium, and Aluminum, and Recovery Effects

1990 ◽  
Vol 47 (8) ◽  
pp. 1604-1615 ◽  
Author(s):  
C. M. Wood ◽  
D. G. McDonald ◽  
C. G. Ingersoll ◽  
D. R. Mount ◽  
O. E. Johannsson ◽  
...  
Keyword(s):  
Brook Trout ◽  
Low Ph ◽  
Yolk Sac ◽  
Whole Body ◽  
Critical Stage ◽  
Adverse Conditions ◽  
Developmental Effects ◽  
Water Ph ◽  
Water Acidity ◽  
Dominant Influence

Water pH, rather than Ca or Al, was the most important factor affecting whole body ions in yolk-sac or swim-up fry exposed to a matrix of pH (6.5–4.0), Ca (0.5–8 mg/L), and Al (0–1000 μg/L). Fry were raised from fertilization (day 0) in flowing soft water (pH = 6.5, Ca = 2 mg/L, Al = 0 μg/L), exposed to pH/Ca/Al on day 49 (yolk-sac, 2 d post-hatch) or day 70 (swim-up) for 21 d, and then allowed to recover a further 20 d. Yolk-sac fry were extremely resistant at [Formula: see text]; developmental effects, as indicated by body weight and Mg, were negligible. However whole body Na, Cl, K, and Ca were depressed by low pH, while water Ca was protective. Aluminum (37–111 μg/L) raised most ions above control values, while higher Al lowered them. Swim-up fry were more sensitive, showing pronounced developmental inhibition (lower weight, higher Mg) under adverse conditions; mortality continued during recovery. Low pH was again the dominant influence on body ions, water Ca was protective, while Al (12–111 μg/L) was only protective and not stimulatory. These effects persisted significantly; indeed responses in body Ca were larger after recovery than after the exposure itself, in the field, emergence from the redd into ambient acidic water is probably the critical stage. Water pH will be the principal determinant of whole body ions in alevins surviving this emergence, in contrast to fry exposed continuously from fertilization.

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