scholarly journals A Simple Cardiovascular Model for the Study of Hemorrhagic Shock

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Luciano Curcio ◽  
Laura D’Orsi ◽  
Fabio Cibella ◽  
Linn Wagnert-Avraham ◽  
Dean Nachman ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Hemorrhagic Shock ◽  
Time Course ◽  
The Other ◽  
Laboratory Animals ◽  
Cardiovascular Model ◽  
Satisfactory Model ◽  
Civilian Trauma ◽  
Experimental Laboratory ◽  
The One

Hemorrhagic shock is the number one cause of death on the battlefield and in civilian trauma as well. Mathematical modeling has been applied in this context for decades; however, the formulation of a satisfactory model that is both practical and effective has yet to be achieved. This paper introduces an upgraded version of the 2007 Zenker model for hemorrhagic shock termed the ZenCur model that allows for a better description of the time course of relevant observations. Our study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. This model is capable of replicating the changes in mean arterial pressure, heart rate, and cardiac output after the onset of bleeding (as observed in four experimental laboratory animals) and achieves a reasonable compromise between an overly detailed depiction of relevant mechanisms, on the one hand, and model simplicity, on the other. The former would require considerable simulations and entail burdensome interpretations. From a clinical standpoint, the goals of the new model are to predict survival and optimize the timing of therapy, in both civilian and military scenarios.

Recovery from bleaching in photoreceptors promoted by biotin, pyruvate, and glucose

1990 ◽  
Vol 4 (05) ◽  
pp. 489-492 ◽  
Author(s):  
K.N. Leibovic ◽  
J. Bandarchi
Keyword(s):  
Time Course ◽  
Response Duration ◽  
Bufo Marinus ◽  
Response Amplitude ◽  
The Other ◽  
Isolated Cells ◽  
Mediated Effects ◽  
Other Hand ◽  
Elevated Glucose ◽  
The One

AbstractIn the rods ofBufo marinusand other species, bleaching of the rhodopsin in isolated cells leads to a loss of sensitivity and response amplitude and to a shortened response duration. These changes are permanent for cells bathed in Ringer&s solution. They are due to as yet unknown modulations in the transduction biochemistry. In this paper, we report that these changes can be partly or completely reversed by supplying biotin, pyruvate, and elevated glucose to the rod. The time course of this reversal and the substances which promote it imply that these are metabolically mediated effects. Based on the reported action of biotin and pyruvate on the one hand and on the changes of the response waveforms on the other hand, we believe that the phenomena we observe involve the later steps of the transduction cycle.

scholarly journals Prediction of the propagation of SARS-CoV-2 in Amapá State, Amazon Region, Brazil, by mathematical modeling

2020 ◽  
pp. 73-95
Author(s):  
Neylan Leal Dias ◽  
Edcarlos Vasconcelos da Silva ◽  
Marcelo Amanajas Pires ◽  
Daniel Chaves ◽  
Katsumi Letra Sanada ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Temporal Evolution ◽  
Sir Model ◽  
Amazon Region ◽  
The Other ◽  
Short Term ◽  
Exponential Behavior ◽  
Linear Projection ◽  
The Third ◽  
The One

This article presents an analysis of the spread of SARS-CoV-2 in Amapá using three approaches. In the first, the ICL model for the pandemic applied to Brazil was used to implement a comparative linear projection for the Amapá population. The second approach was developed with the short-term solution of the standard SIR model where it was shown that the typical exponential behavior satisfactorily describes the data for the first weeks of the epidemic, but soon after there are early discrepancies due to a sudden slowdown in the temporal evolution number of cases due to isolation measures. This new regime is appropriately described with the third approach which is based on the vSIR model which is a variant of the SIR model. The results presented enable, on the one hand, a better understanding of the scenarios already faced by the population and on the other hand provide short-term projections that will be constantly updated on the link[11].

Immunological realtionships during primary infection with Heligmosomides polygyrus (Nematospiroides dubius): expulsion of adult worms from fast responder syngeneic and hybrid strains of mice

Parasitology ◽  
1989 ◽  
Vol 98 (3) ◽  
pp. 459-469 ◽  
Author(s):  
F. N. Wahid ◽  
M. Robinson ◽  
J. M Behnke
Keyword(s):  
High Intensity ◽  
Primary Infection ◽  
Time Course ◽  
The Other ◽  
Mouse Strains ◽  
Heligmosomoides Polygyrus ◽  
Worm Expulsion ◽  
Nematospiroides Dubius ◽  
The One ◽  
Identical Gene

SUMMARYThe time-course of low and high intensity primary infections with Heligmosomoides polygyrus was monitored in SJL and SWR mice, both of which usually expel worms within 7 weeks of larval administration. Worm expulsion in these strains was not dependent on the intensity of infection, with low and high intensity worm burdens being lost within the same period of time. The ability to expel worms rapidly was inherited in a dominant manner in F1 offspring of SJL or SWR mice mated with C57Bl10 mice; the latter being a strain in which no loss of worms was evident within 10 weeks of infection. However, neither (SJL × C57Bl10)F1 nor (SWR × C57Bl10)F1 mice expelled worms as rapidly as the parental SJL and SWR strains. (SWR × B10G)F1 [H-2q] mice eliminated worms faster than (SWR × C57Bl10)F1 [H-2bq], suggesting that the b haplotype had a moderating influence on the expulsion process. In fact (SWR × B10G)F1 mice showed a significant reduction in worm burdens by week 4 but by weeks 6–8 the rate of worm loss had slowed considerably. In contrast, SJL and SWR mice, whilst initiating rejection slightly later, (after week 4) expelled all worms within the following 2 weeks. Thus two distinct patterns of response were observed among the fast responder strains as exemplified by SWR and SJL mice on the one hand and (SWR × B10G)F1 on the other. Our results support the hypothesis that the course of a primary infection with H. polygyrus is influenced by multiple host gene loci, some of which are encoded within the MHC. SJL and SWR mice probably have similar if not identical gene combinations at loci which determine a fast responder phenotype, distinguishing them from the other mouse strains which have been studied.

Changes in milk yield and composition at oestrus in dairy cows

1985 ◽  
Vol 52 (1) ◽  
pp. 9-16 ◽  
Author(s):  
R. Ian Horrell ◽  
Keith L. Macmillan ◽  
Ron Kilgour ◽  
Kaye Bremner
Keyword(s):  
Individual Differences ◽  
New Zealand ◽  
Dairy Cows ◽  
Milk Production ◽  
Time Course ◽  
Dairy Herd ◽  
The Other ◽  
Cow Milk ◽  
Cell Content ◽  
The One

SUMMARYA New Zealand dairy herd of 73 cows was observed at pasture during the breeding season. Individual cow milk yields and composition analyses were obtained before, during and after oestrus. There was an overall reduction in yield at the first, and a rebound enhancement at the second milking after onset of oestrus. Changes in fat content followed the same time course and there was a slight increase in lactose content. Protein and somatic cell content were unaffected. There were considerable individual differences in both the duration and intensity of oestrous behaviour on the one hand, and the extent and timing of the effects on milk production on the other. However no relationship was found between the degree of behavioural excitement shown by a cow in oestrus and its change in milk production.

MODELING CROWD DYNAMICS FROM A COMPLEX SYSTEM VIEWPOINT

2012 ◽  
Vol 22 (supp02) ◽  
pp. 1230004 ◽  
Author(s):  
NICOLA BELLOMO ◽  
BENEDETTO PICCOLI ◽  
ANDREA TOSIN
Keyword(s):  
Mathematical Modeling ◽  
Complex System ◽  
The Other ◽  
Living Systems ◽  
Self Organization ◽  
Mathematical Structures ◽  
Crowd Dynamics ◽  
Research Perspectives ◽  
The One ◽  
Critical Overview

This paper aims at indicating research perspectives on the mathematical modeling of crowd dynamics, pointing on the one hand to insights into the complexity features of pedestrian flows and on the other hand to a critical overview of the most popular modeling approaches currently adopted in the specialized literature. Particularly, the focus is on scaling problems, namely representation and modeling at microscopic, macroscopic, and mesoscopic scales, which, entangled with the complexity issues of living systems, generate multiscale dynamical effects, such as e.g. self-organization. Mathematical structures suitable to approach such multiscale aspects are proposed, along with a forward look at research developments.

scholarly journals On the question of the practical value of the Stamm antigen according to Kalinin and Ginsburg

2021 ◽  
Vol 32 (4) ◽  
pp. 307-312
Author(s):  
S. M. Yunusova
Keyword(s):  
The Other ◽  
Laboratory Animals ◽  
Laboratory Conditions ◽  
Other Hand ◽  
The One ◽  
Wassermann Reaction ◽  
Serodiagnosis Of Syphilis

Soon after the Wassermann reaction was introduced for the diagnosis of syphilis, aspirations appeared that had the goal, on the one hand, to improve the method of serodiagnosis of syphilis in the sense of obtaining more accurate results, since the Wassermann reaction, even with the most careful formulation, is still sometimes gave unsatisfactory results, on the other hand, a simplification of this technique, in order thereby to be able to apply serodiagnostic methods in primitive laboratory conditions, without laboratory animals.

scholarly journals A Mathematical Model of the Cognitive Semantics of the English Preposition ON

2020 ◽  
Vol 5 (1) ◽  
pp. 133-153
Author(s):  
Ruswan Dallyono ◽  
Didi Sukyadi ◽  
Lukman Hakim
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Linguistic Analysis ◽  
Integral Function ◽  
The Other ◽  
Cognitive Semantics ◽  
Geometric Representation ◽  
Academic Texts ◽  
The One

This study aims to present a mathematical linguistic analysis in establishing the relations between TRs, LMs, potential senses, and actual senses by using the case of the preposition on found in academic texts under the framework of Trajector (TR) and Landmark (LM) configurations. Data were corpora taken from 10 bachelor’s theses written by Indonesian students. To sort the data, Ant Conc 3.4.1.0 was used to parse clauses or sentences based on the TR-LM configurations. Based on the TR-LM configurations, a mathematical model was developed to discover how these variables are quantitatively related to the number of potential senses produced by using a geometric representation of TR and LM. This study indicates that the relation between TRs and LMs, on the one hand, and the sum of potential senses, on the other, follows the integral function of , which means that the total number of potential senses of Ps equals the integral of TR with respect to LM. Meanwhile, the total number of actual senses, ∑As can be obtained by the integral function of , which equals TR.LM + C where C is -Ls representing the constant of the number of lost senses. This mathematical modeling confirms that TR-LM configurations may be used to generate senses which prove the polysemous nature of prepositions.

Studies on the Toxicity Of insecticide Films

1949 ◽  
Vol 40 (1) ◽  
pp. 1-25 ◽  
Author(s):  
S. Pradhan
Keyword(s):  
The Other ◽  
Water Lily ◽  
Continuous Contact ◽  
Concentration Time ◽  
Average Survival ◽  
Experimental Laboratory ◽  
High Concentrations ◽  
The One ◽  
Glass Surfaces ◽  
Film Form

Experiments are described in which the concentration-time-mortality relationships with certain insects were investigated for the insecticides DDT and γ-BHC, the insecticides being used in film form. Adults of Tribolium castaneum, the larvae of Plutella maculipennis and adults of the Aphid, Macrosiphoniella sanborni, were used as test insects. T. castaneum proved the most suitable insect for experimental laboratory work on films, since it can be kept in continuous contact with them without difficulty.A description is given of the techniques employed for T. castaneum and also for the other insects which are able to progress on perpendicular glass surfaces. Techniques are described for experiments in which attempts were made to eliminate as far as possible the fumigation effect of γ-BHC and to differentiate it from that of direct contact. The fumigation effect of this compound is considerable and it appears impossible to eliminate it entirely.With T. castaneum the characteristic curves connecting log. concentration with percentage mortality varies with time of exposure, from horizontal lines showing on the one hand zero toxicity and, on the other, complete mortality at all concentrations. Sigmoid curves are represented between these limits. The average survival period of T. castaneum adults gradually decreases with the strength of poison in the film.The surface upon which toxic films are deposited was shown in preliminary experiments to have a definite bearing upon their effectiveness. Waxed surfaces showed least toxicity, and amongst a few leaves used Geum gave the highest and water lily, at lower critical concentrations, the least effect. High concentrations on water lily were little different from others in toxic action.

scholarly journals Mathematical modeling as a bridge between pure and applied mathematics

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Nelson Hein
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Applied Mathematics ◽  
The Other ◽  
Real Situation ◽  
Mathematical Concepts ◽  
Precise Identification ◽  
The One ◽  
Teaching Situations

It is very common to find systems that include mathematical concepts that can be interpreted in real ones. When it is possible to establish some precise identification of the elements of a system on the one hand, and the phenomena or objects of a real situation, on the other, there is a mathematical model of a real situation. The objective of this paper is to present how this can be built to teaching situations, highlighting the possibilities and limits of technical modeling

scholarly journals Nudging the N170 forward with prior stimulation – Bridging the gap between N170 and recognition potential

2020 ◽  
Author(s):  
Canhuang Luo ◽  
Wei Chen ◽  
Rufin VanRullen ◽  
Carl Michael Gaspar ◽  
Ye Zhang
Keyword(s):  
Time Course ◽  
Neural Response ◽  
Stimulus Onset ◽  
The Other ◽  
Neural Responses ◽  
Single Trial ◽  
Measured Effect ◽  
The One ◽  
Gradual Transformation ◽  
Unique Signature

AbstractSome neural responses are classified by the stimulus conditions leading up to that response while other neural responses are also classified by the morphology of the responses themselves. However, morphology-based classification may not be appropriate if one can nudge a neural response into looking like another neural response. Morphology-based classification occurs with the N170 and RP (Recognition Potential), ERP components that are studied in separate literatures and yet share much in common in terms of functionality. In this study, we demonstrate a gradual transformation in the morphology of the N170 to the RP using a simple parametric manipulation of forward masks that is unlikely to cause a change in the underlying processing. Both the N170 and RP are N1 components, meaning that they are the first negative deflection of the evoked response. However, the RP is often measured with a forward mask that ends at stimulus onset whereas the N170 is often measured with no masking at all. This study investigates how ISI may delay and distort the N170 into an RP by manipulating the temporal gap (ISI) between forward mask and target. The results revealed reverse relationships between the ISI on the one hand, and the N170 latency, single-trial N1 jitter (an approximation of N1 width) and reaction time on the other hand. Importantly, we find that scalp topographies have a unique signature at the N1 peak across all conditions, from the longest gap (N170) to the shortest (RP). These findings prove that the mask-delayed N1 is still the same N170, even under conditions that are normally associated with a different component like the RP. In general, our results suggest that greater caution should be taken to interpret the time course of a measured effect when forward masks are employed.

Sign in / Sign up

Export Citation Format

Share Document