828 research outputs found

    Systemic and local responses to repeated HL stress-induced retrograde signaling in Arabidopsis

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    Chloroplasts of leaves under high light stress initiate signals to the nuclei of both exposed and distal leaves in order to acclimate against the potential threat of oxidative damage: a process known as high light systemic acquired acclimation (HL SAA). This study explores the nature of HL SAA, synergistic interactions with other environmental stresses, and the impact of repeated HL stress on the acclimation response of exposed and distal leaves. This necessitated the development of novel experimental systems to investigate the initiation, perception, and response to HL SAA. These systems were used to investigate the HL SAA response by monitoring the induction of mRNA in distal leaves not exposed to the HL stress. Acclimation to HL is induced within minutes and the response is proportionally dependent on the quality and quantity of light. HL SAA treatments in conjunction with variations in temperature and humidity reveal HL SAA is influenced by fluctuations in humidity. These treatments also result in changes in auxin accumulation and auxin-responsive genes. A key question in retrograde signaling is the extent to which transient changes in light intensity result in a "memory" of the event leading to acclimation responses. Repeated exposure to short term HL resulted in acclimation of the exposed tissue and that of emerging and young leaves (but not older leaves) to HL and oxidative stress

    Störung der CO2-Reaktivität bei schwerer Sepsis und im septischen Schock

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    In dieser Studie wurde an 17 Patienten in schwerer Sepsis oder septischem Schock die CO2-Reaktivität der zerebralen Wiederstandsgefäße untersucht. Dabei wurden die Patienten einem multimodalen Monitoring unterzogen, welcher einen Kapnographen, einen Dopplersonographen, ein Nahinfrarotspektrometer und ein nichtinvasives Blutdruckmessgerät einbezog. In schwerer Sepsis und septischem Schock zeigten die Patienten eine signifikante Beeinträchtigung der CO2-Reaktivität im Vergleich zu den Ergebnissen von Messungen an den Patienten außerhalb der Sepsis und auch zu einer Vergleichpopulation von 29 Probanden. Es liegt somit während schwerer Sepsis oder septischem Schock eine reversible signifikante Beeinträchtigung der CO2-Reaktivität vor, was auch ein pathogenetischer Faktor bei der Entwicklung der septischen Enzephalopathie darstellen könnte. Die relativ neue Methode der Nahinfrarotspektroskopie erwies sich als ebenbürtige Methode zur Messung der CO2-Reaktivität im Vergleich zur etablierten Dopplersonographie. (Ob ein Monitoring nach der vorgestellten Methode zur Früherkennung oder Verlaufsbeobachtung einer Sepsis geeignet ist, bedarf noch weitere Studien.

    Atrial Natriuretic Peptide, a Regulator of Nuclear Factor-ÎşB Activation in Vivo

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    Natriuretic peptides (NPs) comprise a family of vasoactive hormones that play important roles in the regulation of cardiovascular and renal homeostasis. Along this line, atrial NP (ANP) (international non-proprietary name: carperitide, HANP) is an approved drug for the treatment of acute heart failure. In recent years, evidence has been given that the NP system possesses a far broader biological spectrum than the regulation of blood pressure and volume homeostasis. In fact, a substantial amount of in vitro work indicates that ANP affects important inflammatory processes and signaling pathways. Quite surprisingly, however, no information exists on the in vivo antiinflammatory potential and signaling of ANP. We show here that pretreatment of lipopolysaccharide (Salmonella abortus equi, 2.5 mg/kg)-challenged mice with ANP (5μg/kg iv, 15 min) rapidly inhibits nuclear factor-κB activation via inhibition of phosphorylation and degradation of the IκB-α protein. ANP also reduces Akt activation upon lipopolysaccharide injection. In ANP-pretreated mice, the increase of TNF-α serum concentration is markedly prevented; most importantly, the survival of these animals improved. These findings demonstrate both in vitro and in vivo an antiinflammatory profile of ANP that deserves to be further investigated in a therapeutic perspective

    Feedback Gathering from an Industrial Point of View

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    Feedback communication channels allow end-users to express their needs, which can be considered in software development and evolution. Although feedback gathering and analysis have been identified as an important topic and several researchers have started their investigation, information is scarce on how software companies currently elicit end-user feedback. In this study, we explore the experiences of software companies with respect to feedback gathering. The results of a case study and online survey indicate two sides of the same coin: on the one hand, most software companies are aware of the relevance of end-user feedback for software evolution and provide feedback channels, which allow end-users to communicate their needs and problems. On the other hand, the quantity and quality of the feedback received varies. We conclude that software companies still do not fully exploit the potential of end-user feedback for software development and evolution

    Repetitive application of remote ischemic conditioning (RIC) in patients with peripheral arterial occlusive disease (PAOD) as a non-invasive treatment option: study protocol for a randomised controlled clinical trial

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    Background The best medical treatment (BMT) for most patients with early stage of peripheral arterial occlusive disease (PAOD) is often limited to gait training and pharmacological therapy besides endovascular surgery. The application of remote ischemic conditioning (RIC) has been described as a promising experimental strategy for the improvement of therapeutic outcome in cardiovascular disease but has not proven beneficial effects in clinical practice and treatment of PAOD yet. Methods Here we describe a prospective, randomized trial for the evaluation of possible effects of repeated application of RIC in patients with PAOD. This monocentric study will enrol 200 participants distributed to an intervention group receiving RIC + BMT and a control group only receiving BMT for four weeks. Patients are at least 18 years of age and have diagnosed PAOD Fontaine stage II b. Pain-free and total walking distance will be measured via treadmill test (primary endpoints). In addition, ankle-brachial index (ABI) and quality of life (QoL) will be assessed using the SF-36 and VascuQoL-6 questionnaire. Moreover, evaluation of markers for atherosclerosis, angiogenic profiling and mononuclear cell characterization will be performed using biochemical assays, proteome profiling arrays and flow cytometry (secondary endpoints). Discussion Our prospective, randomized monocentric trial is the first of its kind to analyse the effects of chronic and repetitive treatment with RIC in patients with PAOD and might provide important novel information on the molecular mechanisms associated with RIC in PAOD patients. Trial registration Prospectively registered in the German Clinical Trials Register (Deutsche Register Klinischer Studien) Registration number: DRKS00025735; Date of registration: 01.07.2021

    Murder She Wrote: Death and Drama in Nesting Woodpeckers

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    Woodpeckers serve a vital role as a keystone species in their respective biome by excavating nesting cavities that are in turn used by numerous forest birds and animals. These secondary cavity nesters rely heavily on the success of primary nesters in order to ensure their own reproductive success. Unfortunately numerous woodpeckers, such as the Black-backed (Picoides arcticus) and White-headed Woodpeckers (Picoides albolarvatus), have seen a large decline in numbers and are now considered a threatened species. Inability for these woodpeckers to reproduce creates a top-down trophic cascade in their biome. In an effort to better understand how nesting success is impacted by the behaviors of woodpeckers, predators, and secondary cavity nesters at the nest, sixty-five different nests were filmed for over 15,000 hours in the Eastern Washington Cascades during the 2015 and 2016 breeding seasons. We have watched and scored close to 400 hours of footage and have documented aggressive takeover by secondary cavity nesters, predation of nest chicks, and even human disturbance of nests. By better understanding the ecological pressures woodpeckers face and identifying what factors contribute to successful nesting, proper measures can be taken to maintain healthy levels of woodpecker populations

    Successful resuscitation from prolonged hypothermic cardiac arrest without extracorporeal life support: a case report.

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    BACKGROUND We report a case of successful prolonged cardiopulmonary resuscitation (5 hours and 44 minutes) following severe accidental hypothermia with cardiac arrest treated without rewarming on extracorporeal life support. CASE PRESENTATION A 52-year-old Italian mountaineer, was trapped in a crevasse and rescued approximately 7 hours later by a professional rescue team. After extrication, he suffered a witnessed cardiac arrest with ventricular fibrillation. Immediate defibrillation and cardiopulmonary resuscitation were started. His core temperature was 26.0 °C. Due to weather conditions, air transport to an extracorporeal life support center was not possible. Thus, he was rewarmed with conventional rewarming methods in a rural hospital. Auto-defibrillation occurred at a core temperature of 29.8 °C after 5 hours and 44 minutes of continued cardiopulmonary resuscitation. With a core temperature of 33.4 °C, he was finally admitted to a level 1 trauma center and extracorporeal life support was no longer required. Seven weeks following the accident, he was discharged home with complete neurological recovery. CONCLUSIONS Successful rewarming from severe hypothermia without extracorporeal life support use as performed in this case suggests that patients with primary hypothermic cardiac arrest have a chance of a favorable neurological outcome even after several hours of cardiac arrest when cardiopulmonary resuscitation and conventional rewarming are performed continuously. This may be especially relevant in remote areas, where extracorporeal life support rewarming is not available

    Does the Aboveground Herbivore Assemblage Influence Soil Bacterial Community Composition and Richness in Subalpine Grasslands?

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    Grassland ecosystems support large communities of aboveground herbivores that are known to directly and indirectly affect belowground properties such as the microbial community composition, richness, or biomass. Even though multiple species of functionally different herbivores coexist in grassland ecosystems, most studies have only considered the impact of a single group, i.e., large ungulates (mostly domestic livestock) on microbial communities. Thus, we investigated how the exclusion of four groups of functionally different herbivores affects bacterial community composition, richness, and biomass in two vegetation types with different grazing histories. We progressively excluded large, medium, and small mammals as well as invertebrate herbivores using exclosures at 18 subalpine grassland sites (9 per vegetation type). We assessed the bacterial community composition using terminal restriction fragment length polymorphism (T-RFLP) at each site and exclosure type during three consecutive growing seasons (2009-2011) for rhizosphere and mineral soil separately. In addition, we determined microbial biomass carbon (MBC), root biomass, plant carbon:nitrogen ratio, soil temperature, and soil moisture. Even though several of these variables were affected by herbivore exclusion and vegetation type, against our expectations, bacterial community composition, richness, or MBC were not. Yet, bacterial communities strongly differed between the three growing seasons as well as to some extent between our study sites. Thus, our study indicates that the spatiotemporal variability in soil microclimate has much stronger effects on the soil bacterial communities than the grazing regime or the composition of the vegetation in this high-elevation ecosystem

    Taxonomic review of the genus Stenotus Jakovlev (Hemiptera: Heteroptera: Miridae) from the Korean Peninsula

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    AbstractA genus Stenotus Jakovlev (Hemiptera: Heteroptera: Miridae) is reviewed taxonomically from the Korean Peninsula with a new record Stenotus binotatus (Fabricius 1794). Morphological information, such as descriptions of male and female genitalia, of the Korean species with photographs and illustrations, and a key to the Korean species are provided

    Deconvolution of the relaxations associated with local and segmental motions in poly(methacrylate)s containing dichlorinated benzyl moieties in the ester residue

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    9 pages, 15 figures, 1 scheme.The relaxation behavior of poly(2,3-dichlorobenzyl methacrylate) is studied by broadband dielectric spectroscopy in the frequency range of 10–1–109 Hz and temperature interval of 303–423 K. The isotherms representing the dielectric loss of the glassy polymer in the frequency domain present a single absorption, called B process. At temperatures close to Tg, the dynamical (alfa) relaxation already overlaps with the (beta) process, the degree of overlapping increasing with temperature. The deconvolution of the (alfa) and (beta) relaxations is facilitated using the retardation spectra calculated from the isotherms utilizing linear programming regularization parameter techniques. The temperature dependence of the (beta) relaxation presents a crossover associated with a change in activation energy of the local processes. The distance between the (alfa) and (beta) peaks, expressed as log(fmax;/fmax;) where fmax is the frequency at the peak maximum, follows Arrhenius behavior in the temperature range of 310–384 K. Above 384 K, the distance between the peaks remains nearly constant and, as a result, the (alfa) onset temperature exhibited for many polymers is not reached in this system. The fraction of relaxation carried out through the (alfa) process, without (beta) assistance, is larger than 60% in the temperature range of 310–384 K where the so-called Williams ansatz holds.This work was financially suported by the DGCYT and CAM through Grant Nos. MAT2002-04042-C02 and GR/ MAT/0723/2004. Two of the authors (L.G. and D.R.) thank the FONDECYT for partial financial support through Grant Nos. 21050956 and 1050962, respectively.Peer reviewe
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