A Preliminary Theoretical Study of Arterial Pressure Perturbations Under Shock Acceleration

1989 ◽  
Vol 111 (3) ◽  
pp. 233-240 ◽  
Author(s):  
E. Belardinelli ◽  
M. Ursino ◽  
E. Iemmi

The artero-venous system is often stressed by accelerative perturbation, not only during exceptional performances, but also in normal life. For example, when the body is subject to fast pressure changes, accelerative perturbations combined with a change in hydrostatic pressure could have severe effects on the circulation. In such cases a preliminary mathematical inquiry, whose results allow qualitative evaluation of the perturbation produced is useful. Pressure variations are studied in this work when the body is subjected both to rectilinear and rotational movements as well as posture change. The dominant modes of the hemodynamic oscillations are emphasized and the numerical simulation results presented. The artery model used for simulation is obviously simplified with respect to the anatomical structure of an artery. Nevertheless, behavior of the main arteries (like the common carotid and aorta) can be approximately described, choosing suitable model parameters. The frequency of blood oscillations strictly depends on the Young modulus of the arterial wall. This connection could be employed for new clinical tests on the state of the arteries.

2010 ◽  
Vol 4 (supplement) ◽  
pp. 46-63
Author(s):  
Vidar Thorsteinsson

The paper explores the relation of Michael Hardt and Antonio Negri's work to that of Deleuze and Guattari. The main focus is on Hardt and Negri's concept of ‘the common’ as developed in their most recent book Commonwealth. It is argued that the common can complement what Nicholas Thoburn terms the ‘minor’ characteristics of Deleuze's political thinking while also surpassing certain limitations posed by Hardt and Negri's own previous emphasis on ‘autonomy-in-production’. With reference to Marx's notion of real subsumption and early workerism's social-factory thesis, the discussion circles around showing how a distinction between capital and the common can provide a basis for what Alberto Toscano calls ‘antagonistic separation’ from capital in a more effective way than can the classical capital–labour distinction. To this end, it is demonstrated how the common might benefit from being understood in light of Deleuze and Guattari's conceptual apparatus, with reference primarily to the ‘body without organs’ of Anti-Oedipus. It is argued that the common as body without organs, now understood as constituting its own ‘social production’ separate from the BwO of capital, can provide a new basis for antagonistic separation from capital. Of fundamental importance is how the common potentially invents a novel regime of qualitative valorisation, distinct from capital's limitation to quantity and scarcity.


Author(s):  
Anne Phillips

No one wants to be treated like an object, regarded as an item of property, or put up for sale. Yet many people frame personal autonomy in terms of self-ownership, representing themselves as property owners with the right to do as they wish with their bodies. Others do not use the language of property, but are similarly insistent on the rights of free individuals to decide for themselves whether to engage in commercial transactions for sex, reproduction, or organ sales. Drawing on analyses of rape, surrogacy, and markets in human organs, this book challenges notions of freedom based on ownership of our bodies and argues against the normalization of markets in bodily services and parts. The book explores the risks associated with metaphors of property and the reasons why the commodification of the body remains problematic. The book asks what is wrong with thinking of oneself as the owner of one's body? What is wrong with making our bodies available for rent or sale? What, if anything, is the difference between markets in sex, reproduction, or human body parts, and the other markets we commonly applaud? The book contends that body markets occupy the outer edges of a continuum that is, in some way, a feature of all labor markets. But it also emphasizes that we all have bodies, and considers the implications of this otherwise banal fact for equality. Bodies remind us of shared vulnerability, alerting us to the common experience of living as embodied beings in the same world. Examining the complex issue of body exceptionalism, the book demonstrates that treating the body as property makes human equality harder to comprehend.


2020 ◽  
Vol 25 (2) ◽  
pp. 338-357
Author(s):  
Cornelius Berthold

AbstractKoran manuscripts that fit comfortably within the palm of one’s hand are known as early as the 10th century CE.For the sake of convenience, all dates will be given in the common era (CE) without further mention, and not in the Islamic or Hijra calendar. Their minute and sometimes barely legible script is clearly not intended for comfortable reading. Instead, recent scholarship suggests that the manuscripts were designed to be worn on the body like pendants or fastened to military flag poles. This is corroborated by some preserved cases for these books which feature lugs to attach a cord or chain, but also their rare occurrence in contemporary textual sources. While pendant Korans in rectangular codex form exist, the majority were produced as codices in the shape of an octagonal prism, and others as scrolls that could be rolled up into a cylindrical form. Both resemble the shapes of similarly dated and pre-Islamic amulets or amulet cases. Building on recent scholarship, I will argue in this article that miniature or pendant Koran manuscripts were produced in similar forms and sizes because of comparable modes of usage, but not necessarily by a deliberate imitation of their amuletic ‘predecessors’. The manuscripts’ main functions did not require them to be read or even opened; some of their cases were in fact riveted shut. Accordingly, the haptic feedback they gave to their owners when they carried or touched them was not one of regular books but one of solid objects (like amulets) or even jewellery, which then reinforced this practice.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yue Yang ◽  
Tingting Di ◽  
Zixiao Zhang ◽  
Jiaxin Liu ◽  
Congli Fu ◽  
...  

Abstract Background Establishment of a mouse model is important for investigating the mechanism of chronic obstructive pulmonary disease (COPD). In this study, we observed and compared the evolution of the pathology in two mouse models of COPD induced by cigarette smoke (CS) exposure alone or in combination with lipopolysaccharide (LPS). Methods One hundred eight wild-type C57BL/6 mice were equally divided into three groups: the (1) control group, (2) CS-exposed group (CS group), and (3) CS + LPS-exposed group (CS + LPS group). The body weight of the mice was recorded, and noninvasive lung function tests were performed monthly. Inflammation was evaluated by counting the number of inflammatory cells in bronchoalveolar lavage fluid and measuring the expression of the IL-6 mRNA in mouse lung tissue. Changes in pathology were assessed by performing hematoxylin and eosin and Masson staining of lung tissue sections. Results The two treatments induced emphysema and airway remodeling and decreased lung function. Emphysema was induced after 1 month of exposure to CS or CS + LPS, while airway remodeling was induced after 2 months of exposure to CS + LPS and 3 months of exposure to CS. Moreover, the mice in the CS + LPS group exhibited more severe inflammation and airway remodeling than the mice in the CS group, but the two treatments induced similar levels of emphysema. Conclusion Compared with the single CS exposure method, the CS + LPS exposure method is a more suitable model of COPD in airway remodeling research. Conversely, the CS exposure method is a more suitable model of COPD for emphysema research due to its simple operation.


Author(s):  
Shatishraj Jothee ◽  
Mohamed Swarhib Shafie ◽  
Faridah Mohd Nor

Abstract Background Previous reported cases on excited delirium syndrome studied on the common clinical manifestations of the syndrome. The usual forensics implication for the syndrome is that death commonly is associated with restraint procedures by law enforcement agencies; however, not many cases reported highlights the difficulties in attributing a violent scene of death to the syndrome. Case presentation We present a case of a partially naked body found in an apartment unit under suspicious circumstances with multiple injuries. The scene of death was violent, and the body was found with blood wiped all over the floor and walls. Investigators believed a violent crime had occurred, and a suspect was reprimanded. However, upon autopsy, it was found that all injuries were superficially inflicted and were unlikely to have been part of an act of commission or caused his death. Internal examination found no remarkable pathology. Toxicology revealed a presence of psychostimulants, that is, methamphetamine, MDMA, and ethyl alcohol. Reconstruction of events by the witness, who was initially suspected of the ‘murder’, revealed that the injuries and his death could likely be explained by an episode of excited delirium. Conclusion The case highlights the challenges faced when attributing excited delirium syndrome as a cause of death. The syndrome can present with injuries from aggressive or bizarre behaviour, coupled with the destruction of property, which may confuse investigators on the possible manner of death.


1989 ◽  
Vol 35 (120) ◽  
pp. 209-213 ◽  
Author(s):  
S.C. Colbeck

Abstract Strong winds can disrupt the thermal regime in seasonal snow because of the variation in surface pressure associated with surface features like dunes and ripples. Topographical features of shorter wavelengths produce stronger surface flows, but the flow decays rapidly with depth. Longer-wavelength features produce weaker surface flows but the flow decays more slowly with depth. The flow may only be strong enough to disrupt the temperature field for features of wavelengths on the scale of meters or tens of meters at wind speeds of 10 m/s or more. Other possible causes of windpumping have been examined but they do not appear to be as significant. Rapid pressure perturbations due to turbulence produce very little displacement of the air because of the high frequency and low amplitude. Barometric pressure changes cause compression and expansion of the air in the pore space, but the rate is too low to have much effect.


2017 ◽  
Vol 52 (14) ◽  
pp. 1947-1958 ◽  
Author(s):  
Sergio González ◽  
Gianluca Laera ◽  
Sotiris Koussios ◽  
Jaime Domínguez ◽  
Fernando A Lasagni

The simulation of long life behavior and environmental aging effects on composite materials are subjects of investigation for future aerospace applications (i.e. supersonic commercial aircrafts). Temperature variation in addition to matrix oxidation involves material degradation and loss of mechanical properties. Crack initiation and growth is the main damage mechanism. In this paper, an extended finite element analysis is proposed to simulate damage on carbon fiber reinforced polymer as a consequence of thermal fatigue between −50℃ and 150℃ under atmospheres with different oxygen content. The interphase effect on the degradation process is analyzed at a microscale level. Finally, results are correlated with the experimental data in terms of material stiffness and, hence, the most suitable model parameters are selected.


2017 ◽  
Vol 284 (1852) ◽  
pp. 20170359 ◽  
Author(s):  
Arjun Nair ◽  
Christy Nguyen ◽  
Matthew J. McHenry

An escape response is a rapid manoeuvre used by prey to evade predators. Performing this manoeuvre at greater speed, in a favourable direction, or from a longer distance have been hypothesized to enhance the survival of prey, but these ideas are difficult to test experimentally. We examined how prey survival depends on escape kinematics through a novel combination of experimentation and mathematical modelling. This approach focused on zebrafish ( Danio rerio ) larvae under predation by adults and juveniles of the same species. High-speed three-dimensional kinematics were used to track the body position of prey and predator and to determine the probability of behavioural actions by both fish. These measurements provided the basis for an agent-based probabilistic model that simulated the trajectories of the animals. Predictions of survivorship by this model were found by Monte Carlo simulations to agree with our observations and we examined how these predictions varied by changing individual model parameters. Contrary to expectation, we found that survival may not be improved by increasing the speed or altering the direction of the escape. Rather, zebrafish larvae operate with sufficiently high locomotor performance due to the relatively slow approach and limited range of suction feeding by fish predators. We did find that survival was enhanced when prey responded from a greater distance. This is an ability that depends on the capacity of the visual and lateral line systems to detect a looming threat. Therefore, performance in sensing, and not locomotion, is decisive for improving the survival of larval fish prey. These results offer a framework for understanding the evolution of predator–prey strategy that may inform prey survival in a broad diversity of animals.


1967 ◽  
Vol 46 (2) ◽  
pp. 307-315 ◽  
Author(s):  
E. DON STEVENS ◽  
D. J. RANDALL

1. Changes in blood pressure in the dorsal aorta, ventral aorta and subintestinal vein, as well as changes in heart rate and breathing rate during moderate swimming activity in the rainbow trout are reported. 2. Blood pressures both afferent and efferent to the gills increased during swimming and then returned to normal levels within 30 min. after exercise. 3. Venous blood pressure was characterized by periodic increases during swimming. The pressure changes were not in phase with the body movements. 4. Although total venous return to the heart increased during swimming, a decreased blood flow was recorded in the subintestinal vein. 5. Heart rate and breathing rate increased during swimming and then decreased when swimming ceased. 6. Some possible mechanisms regulating heart and breathing rates are discussed.


2016 ◽  
Vol 12 (5) ◽  
pp. 24
Author(s):  
Majed F. Mujalli ◽  
Maen Z. Zakarneh ◽  
Ala’a Kh. Abu Aloyoun

<p>The aim of the study was to investigate the common sports injuries among physical activities practitioners at the physical fitness centers in Jordan. Study sample consisted of (272) volunteered male (n=221) and female (n=51) (age 30±3). Researchers used a special form used to evaluate athletic injuries. After collecting and analyzing the data. Results showed that the most common sports injuries among sample of the study was muscular tears 27.7%, muscle spasm 20.7%, and tears ligament 20.2%. And the most exposed parts of the body to injury is the lumbar area 26.8%, elbows 16.9%, followed by shoulders 8.9%. Also the study results revealed that the most cusses of injuries was over training 24.14%. Poor warm-up 22.1% and bad technic 11.3%. Bodies-building was the most type of activities subjects to injury with 18.8%. Physical Fitness 6.6% and weight loss 27.7. Results also showed that physical therapy was the most means of treating injuries 54.14%, drugs therapy 33.3% and surgical intervention 4.2%. Also the study shows that males are more exposed to injuries than females.</p><p>Conclusions: These finding indicate that sports injures is part of physical</p><p>Activities participations, preventive measures should be taken by participant's the researchers recommended the need for physical and medical checkup before participation in physical activity at the physical fitness centers.</p>


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