1,418 research outputs found
Increased collagen synthesis rate during wound healing in muscle
Wound healing in muscle involves the deposition of collagen, but it is not known whether this is achieved by changes in the synthesis or the degradation of collagen. We have used a reliable flooding dose method to measure collagen synthesis rate in vivo in rat abdominal muscle following a surgical incision. Collagen synthesis rate was increased by 480% and 860% on days 2 and 7 respectively after surgery in the wounded muscle compared with an undamaged area of the same muscle. Collagen content was increased by approximately 100% at both day 2 and day 7. These results demonstrate that collagen deposition during wound healing in muscle is achieved entirely by an increase in the rate of collagen synthesis
Functional and Linearity test system for the LHC Beam Loss Monitoring data acquisition card
In the frame of the design and development of the beam loss monitoring (BLM) system for the Large Hadron Collider (LHC) a flexible test system has been developed to qualify and verify during design and production the BLM LHC data acquisition card. It permits to test completely the functionalities of the board as well as realizing analog input signal generation to the acquisition card. The system utilize two optical receivers, a Field Programmable Gate Array (FPGA), eights flexible current sources and a Universal Serial Bus (USB) to link it to a PC where a software written in LabWindows/CVI© (National Instruments) runs. It includes an important part of the measurement processing developed for the BLM in the future LHC accelerator. It is called Beam Loss Electronic Current to Frequency Tester (BLECFT)
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No Evidence of Short-Term Exchange of Meat for Sex among Chimpanzees
The meat-for-sex hypothesis posits that male chimpanzees (Pan troglodytes) trade meat with estrous females in exchange for short-term mating access. This notion is widely cited in the anthropological literature and has been used to construct scenarios about human evolution. Here we review the theoretical and empirical basis for the meat-for-sex hypothesis. We argue that chimpanzee behavioral ecology does not favor the evolution of such exchanges because 1) female chimpanzees show low mate selectivity and require little or no material incentive to mate, violating existing models of meat-for-sex exchange; and 2) meat-for-sex exchanges are unlikely to provide reproductive benefits to either partner. We also present new analyses of 28 years of data from two East African chimpanzee study sites (Gombe National Park, Tanzania; Kanyawara, Kibale National Park, Uganda) and discuss the results of previously published studies. In at least three chimpanzee communities, 1) the presence of sexually receptive females did not increase hunting probability; 2) males did not share preferentially with sexually receptive females and 3) sharing with females did not increase a male’s short-term mating success. We acknowledge that systematic meat-sharing by male chimpanzees in expectation of or as reward for immediate copulations might be discovered in future studies of chimpanzees. However current data indicate that such exchanges are so rare in studied populations, and are so different in nature from exchanges among humans, that with respect to chimpanzees, sexual bartering in humans should be regarded as a derived trait with no known antecedents in the behavior of wild chimpanzees.Human Evolutionary Biolog
Propofol and sevoflurane induce distinct burst suppression patterns in rats
Burst suppression is an EEG pattern characterized by alternating periods of high-amplitude activity (bursts) and relatively low amplitude activity (suppressions). Burst suppression can arise from several different pathological conditions, as well as from general anesthesia. Here we review current algorithms that are used to quantify burst suppression, its various etiologies, and possible underlying mechanisms. We then review clinical applications of anesthetic-induced burst suppression. Finally, we report the results of our new study showing clear electrophysiological differences in burst suppression patterns induced by two common general anesthetics, sevoflurane and propofol. Our data suggest that the circuit mechanisms that generate burst suppression activity may differ among general anesthetics
Depression as Sickness Behavior? A Test of the Host Defense Hypothesis in a High Pathogen Population
Sadness is an emotion universally recognized across cultures, suggesting it plays an important functional role in regulating human behavior. Numerous adaptive explanations of persistent sadness interfering with daily functioning (hereafter “depression”) have been proposed, but most do not explain frequent bidirectional associations between depression and greater immune activation. Here we test several predictions of the host defense hypothesis, which posits that depression is part of a broader coordinated evolved response to infection or tissue injury (i.e. “sickness behavior”) that promotes energy conservation and reallocation to facilitate immune activation. In a high pathogen population of lean and relatively egalitarian Bolivian foragerhorticulturalists, we test whether depression and its symptoms are associated with greater baseline concentration of immune biomarkers reliably associated with depression in Western populations (i.e. tumor necrosis factor alpha [TNF-α], interleukin-1 beta [IL-1β], interleukin-6 [IL-6], and C-reactive protein [CRP]). We also test whether greater pro-inflammatory cytokine responses to ex vivo antigen stimulation are associated with depression and its symptoms, which is expected if depression facilitates immune activation. These predictions are largely supported in a sample of older adult Tsimane (mean±SD age=53.2±11.0, range=34-85, n=649) after adjusting for potential confounders. Emotional, cognitive and somatic symptoms of depression are each associated with greater immune activation, both at baseline and in response to ex vivo stimulation. The association between depression and greater immune activation is therefore not unique to Western populations. While our findings are not predicted by other adaptive hypotheses of depression, they are not incompatible with those hypotheses and future research is necessary to isolate and test competing predictions
Wire scanners and vibrations: models and measurements
The new fast wire scanner foreseen to measure small
emittance beams throughout the LHC injector chain will
have a wire travelling at a speed of up to 20 m.s-1, with a
requested wire position measurement accuracy in the
order of a few microns. The vibration of the thin carbon
wires used has been identified as one of the major error
sources on the wire position accuracy. One of the most
challenging and innovative developments in this project
has been the work to quantify the effect of wire vibrations
and fork deformation. The measurement strategy for the
former is based on the piezo resistive effect of the wire
itself, while the deflection of the fork supporting the wire
has been measured by semiconductor strain gauges.
Dynamic models of the wire and fork have been created
to predict the behaviour of the fork-wire assembly and
will be used for its optimisation. This contribution will
discuss the measurement setup and the model
development as well as their comparison. In addition it
will show that this technology can easily be implemented
in current operating devices without major modifications.Postprint (published version
Video; Health Law & Ethics 2020
This program will focus on the current climate of health law and the necessary steps used through federal practice to adjust to the ever-changing atmosphere of new legislation. Attendees will learn about the various paths within the practice, about emerging new laws, outreach and training, and how to become involved in the federal practice of health law. The presenters will explain what you need to get started, what different types of experiences and exposure might be helpful in entering the field and instruct you on maintaining ethics by knowing and following the Federal Rules of Civil Procedure and Model Rules of Professional Responsibility.
By utilizing key tips and strategies, you will learn how to position yourself for a strong career in federal practice by learning about the different avenues of health law and how to effectively represent clients in this field of law. Discussions will include a general overview of health law, the impact of COVID-19 in conjunction with health law, and the enactment of new laws and statutes created. This program is for students, new and seasoned attorneys alike
Associations Between Male Testosterone and Immune Function in a Pathogenically Stressed Forager-Horticultural Population
Objectives—Despite well-known fitness advantages to males who produce and maintain high endogenous testosterone levels, such phenotypes may be costly if testosterone-mediated investment in reproductive effort trade-off against investment in somatic maintenance. Previous studies of androgen-mediated trade-offs in human immune function find mixed results, in part because most studies either focus on a few indicators of immunity, are confounded by phenotypic correlation, or are observational. Here the association between male endogenous testosterone and 13 circulating cytokines are examined before and after ex vivo antigen stimulation with phytohaemagglutinin (PHA) and lipopolysaccharides (LPS) in a high pathogen population of Bolivian forager-horticulturalists.
Materials and Methods—A Milliplex 13-plex cytokine panel measured cytokine concentration in whole blood samples from 109 Tsimane men aged 40–89 (median=50 years) before and after antigen stimulation with PHA and LPS. Urinary testosterone was measured via enzyme immunoassay; demographic and anthropometric data were collected as part of the Tsimane Health and Life History Project.
Results—Higher endogenous testosterone was associated with down-regulated responses in all cytokines after PHA stimulation (but significantly in only 2/13 cytokines), controlling for age and body mass index. In contrast, testosterone was not significantly associated with down-regulation of cytokines after LPS stimulation. MANOVAs indicate that men with higher testosterone showed reduced cytokine responses to PHA compared to LPS (p=0.0098).
Discussion—Endogenous testosterone appears to be immunomodulatory rather than immunosuppressive. Potentially costlier forms of immune activation like those induced by PHA (largely T-cell biased immune activation) are down-regulated in men with higher testosterone, but testosterone has less impact on potentially less costly immune activation following LPS stimulation (largely B-cell mediated immunity)
Caught on camera:a video assessment of suspected concussion and other injury events in women's rugby union
Objectives: The objective of this study was to identify and report the incidence and mechanisms of suspected injury and concussion in women's rugby union. Design: A cross-sectional video analysis study. Methods: Using video analysis of non-professional, single-angle footage, cases of suspected injury and concussion were identified and reported, based on content validation and consensus by eight rugby-specific researchers, therapists, and sport medicine physicians. Results: There were 225 suspected injuries recorded in 48 games [Suspected injury rate (IR) = 117.5/1000 h (95 % CI;102.6–133.9) or 4.7 suspected injuries per match]. The on-field medical attention IR was 95.0/1000 h (95 % CI;81.7–109.9: 3.8 per game). Suspected concussions accounted for 26 % of injuries (30.8/1000 h: 95 % CI;23.5–39.7: 1.2 per game). The attacking team sustained 64 % of suspected injuries. Permanent removal from play was observed for 29 % of suspected injuries. The most common suspected injury locations were head/neck (28.4 %) and lower extremity (27.6 %). The tackle accounted for 67.1 % of all suspected injuries, with a propensity of 11.2/1000 tackle events (95 % CI;9.5–13.2) or 3.1 tackle-related injuries/game. Of tackle-related injuries, 63.6 % were to the ball carrier while 52.2 % of tackle-related concussions were to the ball carrier. Conclusion: This study adds to the growing body of literature examining women's rugby. The rate of suspected injury is high compared with other studies. It is acknowledged that these are suspected injuries not supported by prospective injury surveillance. The high proportion of suspected injuries that are tackle-related warrants specific attention to identify tackle characteristics associated with injury and concussion.</p
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