11 resultados para Will to Power
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
The intestinal ecosystem is formed by a complex, yet highly characteristic microbial community. The parameters defining whether this community permits invasion of a new bacterial species are unclear. In particular, inhibition of enteropathogen infection by the gut microbiota ( = colonization resistance) is poorly understood. To analyze the mechanisms of microbiota-mediated protection from Salmonella enterica induced enterocolitis, we used a mouse infection model and large scale high-throughput pyrosequencing. In contrast to conventional mice (CON), mice with a gut microbiota of low complexity (LCM) were highly susceptible to S. enterica induced colonization and enterocolitis. Colonization resistance was partially restored in LCM-animals by co-housing with conventional mice for 21 days (LCM(con21)). 16S rRNA sequence analysis comparing LCM, LCM(con21) and CON gut microbiota revealed that gut microbiota complexity increased upon conventionalization and correlated with increased resistance to S. enterica infection. Comparative microbiota analysis of mice with varying degrees of colonization resistance allowed us to identify intestinal ecosystem characteristics associated with susceptibility to S. enterica infection. Moreover, this system enabled us to gain further insights into the general principles of gut ecosystem invasion by non-pathogenic, commensal bacteria. Mice harboring high commensal E. coli densities were more susceptible to S. enterica induced gut inflammation. Similarly, mice with high titers of Lactobacilli were more efficiently colonized by a commensal Lactobacillus reuteri(RR) strain after oral inoculation. Upon examination of 16S rRNA sequence data from 9 CON mice we found that closely related phylotypes generally display significantly correlated abundances (co-occurrence), more so than distantly related phylotypes. Thus, in essence, the presence of closely related species can increase the chance of invasion of newly incoming species into the gut ecosystem. We provide evidence that this principle might be of general validity for invasion of bacteria in preformed gut ecosystems. This might be of relevance for human enteropathogen infections as well as therapeutic use of probiotic commensal bacteria.
Resumo:
Palestinian refugees registered with UNRWA and their housing conditions are officially characterized by a “ temporary status” , a situation which has lasted the past sixty years. This article explores this time-paradox by focusing on the host governments’ and UNRWA’s policies affecting the refugees’ housing conditions. After having reviewed available literature, this contribution analyses the current housing situation. Drawing on data from a recent survey, the authors provide insights on areas where intervention is needed. In all UNRWA’s fields of operation, overcrowding, lack of public spaces, humidity and structural defects are the main sources of housing discomfort that camp refugees endure. Host countries’ restrictions as well as the incapacity or unwillingness of larger urban municipalities to incorporate refugee camps in their master plans are among the main obstacles to the refugees’ housing development. Rehabilitation and self-help re-housing programs may offer substantial incentives for housing improvement. The success of such programs depends, among several factors, on the host governments’ good will to provide UNRWA with authorizations, financial support, and land, as well as on the capacity of involving the refugee communities in projects’ planning and implementation.
Resumo:
In humans, theta band (5-7 Hz) power typically increases when performing cognitively demanding working memory (WM) tasks, and simultaneous EEG-fMRI recordings have revealed an inverse relationship between theta power and the BOLD (blood oxygen level dependent) signal in the default mode network during WM. However, synchronization also plays a fundamental role in cognitive processing, and the level of theta and higher frequency band synchronization is modulated during WM. Yet, little is known about the link between BOLD, EEG power, and EEG synchronization during WM, and how these measures develop with human brain maturation or relate to behavioral changes. We examined EEG-BOLD signal correlations from 18 young adults and 15 school-aged children for age-dependent effects during a load-modulated Sternberg WM task. Frontal load (in-)dependent EEG theta power was significantly enhanced in children compared to adults, while adults showed stronger fMRI load effects. Children demonstrated a stronger negative correlation between global theta power and the BOLD signal in the default mode network relative to adults. Therefore, we conclude that theta power mediates the suppression of a task-irrelevant network. We further conclude that children suppress this network even more than adults, probably from an increased level of task-preparedness to compensate for not fully mature cognitive functions, reflected in lower response accuracy and increased reaction time. In contrast to power, correlations between instantaneous theta global field synchronization and the BOLD signal were exclusively positive in both age groups but only significant in adults in the frontal-parietal and posterior cingulate cortices. Furthermore, theta synchronization was weaker in children and was--in contrast to EEG power--positively correlated with response accuracy in both age groups. In summary we conclude that theta EEG-BOLD signal correlations differ between spectral power and synchronization and that these opposite correlations with different distributions undergo similar and significant neuronal developments with brain maturation.
Resumo:
Energy-harvesting devices attract wide interest as power supplies of today's medical implants. Their long lifetime will spare patients from repeated surgical interventions. They also offer the opportunity to further miniaturize existing implants such as pacemakers, defibrillators or recorders of bio signals. A mass imbalance oscillation generator, which consists of a clockwork from a commercially available automatic wrist watch, was used as energy harvesting device to convert the kinetic energy from the cardiac wall motion to electrical energy. An MRI-based motion analysis of the left ventricle revealed basal regions to be energetically most favorable for the rotating unbalance of our harvester. A mathematical model was developed as a tool for optimizing the device's configuration. The model was validated by an in vitro experiment where an arm robot accelerated the harvesting device by reproducing the cardiac motion. Furthermore, in an in vivo experiment, the device was affixed onto a sheep heart for 1 h. The generated power in both experiments-in vitro (30 μW) and in vivo (16.7 μW)-is sufficient to power modern pacemakers.
Resumo:
Background: Today’s medical devices are powered by batteries with a limited energy storage capacity. Depleted batteries have to be replaced, exposing the patients to the risk of adverse events. Thus, a method for harvesting energy inside the body is desirable since it would allow building devices without batteries. Methods: A miniaturized intravascular Tesla turbine was implanted as an arteriovenous shunt between the common carotid artery and external jugular vein of a pig. The harvested energy was used to power a custom-built temporary cardiac pacemaker. Results: At a flow rate of ~150 ml/min, an output power of 0.4 mW was measured. Successful ventricular pacing was performed. Conclusion: Harvesting energy from the circulation using an intravascular turbine is technically feasible and provides enough energy to power a cardiac pacemaker.
Resumo:
To nie przypadek, że wyrażenie „wieczna kobiecość" ukute przez Goethego zbiega się w czasie z pierwszymi zachodnimi próbami emancypacji kobiet. W chwili, kiedy model kobiety istniejącej tylko w zależności od mężczyzny zaczyna być kwestionowany, kategoria wiecznej kobiecości pozwala ponownie potwierdzić ten model, wypełniając go pozytywnymi wartościami. Naturą kobiety jest być uległą i oddaną, a te cechy sprawiają, że kobieta jest depozytariuszem wszelkiej potencjalnej zbawczej łaski. Tak w Fauście Goethego, przypada Małgorzacie, dziewczynie naiwniej, niewinnej, niewykształconej i bez własnej woli, wykupić Fausta siłą swojej miłości. Wszystko dzieje się tak, jakby pozytywna kodyfikacja właściwości kobiet dzięki kategorii wiecznej kobiecości służyła tylko lepszemu ukryciu rzeczywistości ich ucisku; feministki jednak nie dają się zwieść: ideały popierane przez kategorię wiecznej kobiecości są a priori niezgodne z emancypacją kobiet. Karolina Světlá, jedna z najważniejszych postaci w walce o zrównanie praw między mężczyznami i kobietami w Czechach w XIX wieku, wykorzystywała przecież intensywnie w swojej literackiej twórczości ten model kobiety, która poświęca się dla kochanego mężczyzny i tym samym udaje się jej go "podciągnąć do góry" ("hinan zu ziehen", Goethe) oraz dać mu dostęp do "nieskończoności", "nieśmiertelności" i "wieczności". Czy jej teoretyczne pisma i jej działalność na rzecz emancypacji kobiet zaprzeczałyby jej tekstom literackim, na pierwszy rzut oka tak konwencjonalnym? W tym wykładzie podejmuję próbę odpowiedzi na to pytanie uważną lekturą jednego z jej najbardziej faustowskich opowiadań, mianowice "Czarna dziewanna".
Resumo:
Time-based indoor localization has been investigated for several years but the accuracy of existing solutions is limited by several factors, e.g., imperfect synchronization, signal bandwidth and indoor environment. In this paper, we compare two time-based localization algorithms for narrow-band signals, i.e., multilateration and fingerprinting. First, we develop a new Linear Least Square (LLS) algorithm for Differential Time Difference Of Arrival (DTDOA). Second, fingerprinting is among the most successful approaches used for indoor localization and typically relies on the collection of measurements on signal strength over the area of interest. We propose an alternative by constructing fingerprints of fine-grained time information of the radio signal. We offer comprehensive analytical discussions on the feasibility of the approaches, which are backed up by evaluations in a software defined radio based IEEE 802.15.4 testbed. Our work contributes to research on localization with narrow-band signals. The results show that our proposed DTDOA-based LLS algorithm obviously improves the localization accuracy compared to traditional TDOA-based LLS algorithm but the accuracy is still limited because of the complex indoor environment. Furthermore, we show that time-based fingerprinting is a promising alternative to power-based fingerprinting.
Resumo:
On 9 February 2014, the Swiss people accepted the popular initiative “against mass immigration” launched by the national-conservative Swiss People’s Party (SVP). This voting outcome has triggered wide-ranging debates about both the policy on immigrants as well as the future of Switzerland within the European context. Against this background, we evaluate attitudes toward immigration in Switzerland. Using hitherto unexplored survey data of MOSAiCH, our empirical analyses show that already in the year 2013, before the debate about the initiative on mass immigration was in full swing, roughly 53 percent of the 1011 interviewed Swiss citizens stated that immigration should be reduced. Moreover, our estimations indicate that the threats and fears induced by immigration and the will to maintain sovereignty and autonomy are particularly relevant for attitudes toward immigration. By contrast, education and national or personal economic conditions are only weakly related to the immigration issue.
Resumo:
In Plato’s dialogues, the Phaedo, Laches, and Republic, Socrates warns his interlocutors about the dangers of misology. Misology is explained by analogy with misanthropy, not as the hatred of other human beings, but as the hatred of the logos or reasonable discourse. According to Socrates, misology arises when a person alternates between believing an argument to be correct, and then refuting it as false. If Socrates is right, then misanthropy is sometimes instilled when a person goes from trusting people to learning that others sometimes betray our reliance and expectations, and finally not to placing any confidence whatsoever in other people, or, in the case of misology, in the correctness or trustworthiness of arguments. A cynical indifference to the soundness of arguments generally is sometimes associated with Socrates’ polemical targets, the Sophists, at least as Plato represents Socrates’ reaction to these itinerant teachers of rhetoric, public speaking and the fashioning of arguments suitable to any occasion. Socrates’ injunctions against misology are largely moral, pronouncing it ‘shameful’ and ‘very wicked’, and something that without further justification we must ‘guard against’, maintaining that we will be less excellent persons if we come to despise argument as lacking the potential of leading to the truth. I examine Socrates’ moral objections to misology which I show to be inconclusive. I consider instead the problem of logical coherence in the motivations supposedly underlying misology, and conclude that misology as Socrates intends the concept is an emotional reaction to argumentation on the part of persons who have not acquired the logical dialectical skills or will to sort out good from bad arguments. We cannot dismiss argument as directed toward the truth unless we have a strong reason for doing so, and any such argument must itself presuppose that at least some reasoning can be justified in discovering and justifying belief in interesting truths. The relevant passages from Socrates’ discussion of the soul’s immortality in the Phaedo are discussed in detail, and set in scholarly background against Socrates’ philosophy more generally, as represented by Plato’s dialogues. I conclude by offering a suggestive list of practical remedies to avoid the alienation from argument in dialectic with which Socrates is concerned.
Resumo:
Cardiac pacemakers are routinely used for the treatment of bradyarrhythmias. Contemporary pacemakers are reliable and allow for a patient specific programming. However, pacemaker replacements due to battery depletion are common (~25 % of all implantation procedures) and bear the risk of complications. Batteryless pacemakers may allow overcoming this limitation. To power a batteryless pacemaker, a mechanism for intracorporeal energy harvesting is required. Such a generator may consist out of subcutaneously implanted solar cells, transforming the small amount of transcutaneously available light into electrical energy. Alternatively, intravascular turbines may harvest energy from the blood flow. Energy may also be harvested from the ventricular wall motion by a dedicated mechanical clockwork converting motion into electrical energy. All these approaches have successfully been tested in vivo. Pacemaker leads constitute another Achilles heel of contemporary pacemakers. Thus, leadless devices are desired. Miniaturized pacemaker circuits and suitable energy harvesting mechanisms (incorporated in a single device) may allow catheter-based implantation of the pacemaker in the heart. Such miniaturized battery- and leadless pacemakers would combine the advantages of both approaches and overcome major limitations of today’s systems.
Resumo:
Maternal thromboembolism and a spectrum of placenta-mediated complications including the pre-eclampsia syndromes, fetal growth restriction, fetal loss, and abruption manifest a shared etiopathogenesis and predisposing risk factors. Furthermore, these maternal and fetal complications are often linked to subsequent maternal health consequences that comprise the metabolic syndrome, namely, thromboembolism, chronic hypertension, and type II diabetes. Traditionally, several lines of evidence have linked vasoconstriction, excessive thrombosis and inflammation, and impaired trophoblast invasion at the uteroplacental interface as hallmark features of the placental complications. "Omic" technologies and biomarker development have been largely based upon advances in vascular biology, improved understanding of the molecular basis and biochemical pathways responsible for the clinically relevant diseases, and increasingly robust large cohort and/or registry based studies. Advances in understanding of innate and adaptive immunity appear to play an important role in several pregnancy complications. Strategies aimed at improving prediction of these pregnancy complications are often incorporating hemodynamic blood flow data using non-invasive imaging technologies of the utero-placental and maternal circulations early in pregnancy. Some evidence suggests that a multiple marker approach will yield the best performing prediction tools, which may then in turn offer the possibility of early intervention to prevent or ameliorate these pregnancy complications. Prediction of maternal cardiovascular and non-cardiovascular consequences following pregnancy represents an important area of future research, which may have significant public health consequences not only for cardiovascular disease, but also for a variety of other disorders, such as autoimmune and neurodegenerative diseases.