432 research outputs found
Inexpensive net solar flux radiometer
Radiometer measures the absorption and reflection of solar radiation by opaque and translucent surfaces. Surface-coating modifications permit measurements over selected broad wavelength bands within the solar spectrum
Einfluss transkranieller Gleichstromstimulation auf gesunde und aphasische Sprachprozessierung
Einleitung: Neuromodulatorische Verfahren werden zunehmend hinsichtlich ihres Potentials, kortikale Leistungsfähigkeit zu beeinflussen, evaluiert. Transkranielle Gleichstromstimulation (tDCS) hat in ersten Studien positive Effekte auf motorische und höhere kognitive Funktionen zeigen können. Für die Beeinflussung der Sprachdomäne bei gesunden und aphasischen Probanden liegen noch keine belastbaren Ergebnisse aus RCTs vor. Deshalb soll bei gesunden Probanden der Einfluss auf ein mehrtägiges Lernen neuer lexikalischer Inhalte evaluiert werden. In der aphasischen Rehabilitation sollen das Fazilitierungspotential von Sprachlernprozessen sowie zugrundeliegende neuronale Wirkmechanismen evaluiert werden.
Methodik: Studie 1 soll als Machbarkeitsstudie prüfen, ob Sprachlernprozesse durch CPJ-atDCS bei gesunden, jungen Probanden in ihrer Wirksamkeit gesteigert werden können. In einem zweiarmigen Design lernen 40 Probanden über fünf Tage neue lexikalische Einträge unter CPJ-atDCS oder SHAM-tDCS, behaviorale Leistungen werden unmittelbar nach dem Training und nach Ablauf einer Woche erhoben. Studie 2 untersucht den Einfluss von M1-atDCS auf ein hochfrequentes Benenntraining bei chronischer Aphasie sowie die Wirkung auf ungelernte Kontrollitems und alltagsrelevante Sprache mit sechsmonatiger Nachuntersuchung. In einem zweiarmigen Design wurden 26 Probanden während acht Tagen in jeweils zwei 90minütigen Therapiesitzungen simultan atDCS oder sham-tDCS appliziert. Studie 3 identifiziert neuronale Korrelate von M1-atDCS unter simultaner funktioneller Bildgebung und vermeidet durch einen provozierten Deckeneffekt konfundierende Korrelate behavioraler Veränderungen: 14 Patienten mit Restaphasie wurden unter funktioneller Bildgebung und simultan stattfindender M1-atDCS zuvor korrekt und rasch benannte Items präsentiert und resultierende kortikale Aktivierungsmuster mit denen einer gesunden Kontrollgruppe verglichen.
Ergebnisse: In Studie 1 zeigten sich unter TPJ-atDCS umfassendere und schnellere Lernleistungen, die unmittelbar nach der Intervention und nach Ablauf einer Woche nachweisbar waren. In Studie 2 zeigten sich nach M1-atDCS eine bessere Konsolidierung von Therapie- und Transfereffekten sowie eine Generalisierung auf die Alltagskommunikation. In Studie 3 zeigten sich als neuronales Korrelat von M1-atDCS eine Abnahme der kortikalen Aktivierungsintensität im anterioren cingulären Cortex, linken Inselkortex und rechtem Gyrus lingualis bei gesteigerter funktioneller Konnektivität des verbliebenen sprachlichen Netzwerks sowie eine Annäherung an Aktivierungsmuster der gesunden Kontrollen.
Schlussfolgerung: Mit in Quantität und Akzeleration gesteigerter Einspeicherung neuer lexikalischer Einträge bei jungen gesunden Probanden zeigte tDCS das Potential, Sprachlernprozesse in ihrer Wirksamkeit zu steigern. Signifikant bessere Konsolidierungsleistungen unter Verum für trainierte Items, signifikant gesteigerte Transferleistungen und Verbesserungen in alltagsrelevanten Kommunikationsparametern verdeutlichen das Potential dieses neuromodulatorischen Verfahrens in der Rehabiliation aphasischer Beeinträchtigungen. Als zugrundeliegender Wirkmechanismus konnte ein reduzierter kortikaler Prozessierungsaufwand bei gesteigerter funktioneller Konnektivität aufgabenspezifischer Netzwerke identifiziert werden.Introduction: Recently, growing interest emerged in the enhancement of human potential by means of non-invasive brain stimulation. In particular, atDCS has been shown to exert beneficial effects on motor and higher cognitive functions. High quality studies fulfilling methodically first class criteria assessing the impact of multiple stimulation sessions are scarce and have not yet been conducted in the language domain with healthy individuals and patients with aphasia.
Methods: Study 1 aimed to investigate, whether language learning could be facilitated by atDCS in healthy young participants. In this two armed study 40 participants learned new lexical entries over five days with simultaneous CPJatDCS. Study 2 aimed to evaluate the potential benefits of M1-atDCS in a high frequent naming therapy in chronic aphasia. In this two armed study 26 patients were treated over eight days. Behavioral Performance and communicative skills were tested immediately after the training and after a six-months-follow-up. Study 3 aimed to identify the neuronal underpinning of M1-atDCS with fMRI. In a crossover-study 14 patients suffering from residual aphasia namend items during an fMRI scan with
6
simultaneous application M1-atDCS, cortical activation was compared with healthy controls.
Results: In study 1 TPJ-atDCS facilitated more and faster learning, results were maintained throughout the one-week-follow-up. In study 2 M1-atDCS evoked better consolidation of facilitated naming results and transfer effects as well as generalization on daily communication skills rated by primary care giver. Consolidation remained stable during six months follow-up in the active group, while participants receiving sham-stimulation dropped down to baseline niveau. In study 3 a significant decrease of cortical activation in the anterior cingulate cortex, left insula and right lingual gyrus accompanied with a significant increase in functional connectivity of the remaining language- and task-related network could be identified as neuronal correlate of M1-atDCS. Compared with healthy controls, atDCS resulted in overall “normalization” of brain function in the patients.
Discussion: These results elucidate the potential of tDCS in rehabilitation of language impairment in aphasia. Reduced cortical effort in language processing and increased language- and task-related functional connectivity seem to be the neuronal underpinning of these tDCS effects. The present studies provide direct evidence that atDCS facilitates language learning over repeated sessions in healthy individuals and that these gains are maintained over time. Thereby, these results contribute important novel information about the potential of atDCS to enhance language re-learning in clinical populations
Role of cardiac troponin I phosphorylation in cardiac function: From molecule to mouse
Abstract only availableThe regulation of cardiac muscle contraction involves the interplay between a variety of molecules on the thick and thin filaments. One important regulatory molecule is troponin, which consists of three subunits, troponin C (TnC) that binds calcium, troponin T (TnT) that binds tropomyosin, and troponin I (TnI) that binds actin and tends to inhibit contraction. Following muscle excitation, cytoplasmic calcium rises and binds TnC, which causes a conformational change in TnI that reduces its affinity for actin; this, in turn, allows TnT and tropomyosin to shift positions revealing myosin binding sites on actin, leading to muscle contraction. Interestingly, cardiac troponin I (cTnI) has several phosphorylation sites, which are known to modulate this regulatory process. For example, phosphorylation of serines 23 and 24 on cTnI by protein kinase A (PKA) is known to decrease the calcium binding affinity of cardiac TnC and, thus, thought to speed muscle relaxation. On the other hand, phosphorylation of cTnI on serines 43 and 45 and threonine 144 by protein kinase C (PKC) decreases both force production and calcium sensitivity of force and is thought to contribute to depressed ventricular function in failing hearts. In this study we investigated the effects of chronic cTnI phosphorylation on cardiac function from transgenic animals in which either PKA phosphorylation sites (Ser-23/Ser-24) (PP) or both the PKA and PKC phosphorylation sites (Ser-23/Ser-24/Ser-43/Ser-45/T-144) (All-P) were replaced with aspartic acid to mimic phosphorylation. Left ventricular cardiac myocytes from PP transgenic mice exhibited less calcium sensitivity of force while myocytes from All-P transgenic mice exhibited decreased maximal force, decreased calcium sensitivity of force, and decreased power output, implicating a dominate role of PKC phosphorylation sites on myofilament function. Consistent with these single myocyte studies, left ventricular power output also was depressed in All-P mice compared to both WT and PP transgenic ventricles. We next tested the hypothesis that PP transgenic mice would engage in greater voluntary running compared to WT and All-P transgenic animals. In contrast to this idea, WT and All-P mice ran ~3- and ~4-fold more than the PP transgenic mouse, respectively. Overall, these results indicate that PKC phosphorylation of cTnI plays a dominant role in depressing contractility and may contribute to the maladaptive behavior.NIH grant to K.S. McDonal
Enhanced tissue engineering properties of osteoinductive chitosan hydrogel
[EMBARGOED UNTIL 6/1/2023] Lower back pain is a considerable medical problem that will impact 80 percent of the U.S. population at some point in their life. With the most severe cases, surgical repair is necessary and is associated with costs upwards of $10.2 billion annually in the United States. To allieviate back pain, spine fusions are a common treatment in which two or more vertebrae are biologically fused together often through the use of a graft material. Unfortunately, iliac crest bone autograft, the current gold standard graft material, can yield insufficient fusion and is associated with considerable donor site morbidity and pain as well as limited supply. Therefore, new materials need to be developed in order to better coordinate healing and new bone growth in the affected area to reduce unnecessary patient burden. In order to address this issue, the incorporation of allograft and one of two types of cellulose (i.e., 0CNCs and CNFs) into a dual-crosslinked chitosan hydrogel loaded with bioactive calcium phosphate was investigated. Hydrogels were then tested for both their material and biological properties. Specifically, hydrogel swelling ratio, mass loss, ion release profile, compressive strength, biocompatibility, and osteoinduction were determined. Cellulose and allograft incorporation significantly improved compressive strength and biocompatibility. CNFs were found to be a significantly more biocompatible form of cellulose when compared to 0CNCs. Additionally, through the controlled delivery of osteoinductive simple signaling molecules (i.e., calcium and phosphate ions), CNF/Chitosan hydrogels were able to induce osteoblast-like activity in murine mesenchymal stem cells. This research provides support for our novel material to be further investigated in vivo for its application in spine fusion procedures.Includes bibliographical references
Disease acceptance and adherence to imatinib in Taiwanese chronic myeloid leukaemia outpatients
Background The launch of imatinib has turned chronic myeloid leukaemia (CML) into a chronic illness due to the dramatic improvement in survival. Several recent studies have demonstrated that poor adherence to imatinib may hamper the therapeutic outcomes and result in increased medical expenditures, whilst research on exploring the reasons for non-adherence to imatinib is still limited. Objective This study aimed to explore the experience of patients as they journey through their CML treatments and associated imatinib utilisation in order to understand the perceptions, attitudes and concerns that may influence adherence to imatinib treatment. Setting This study was conducted at oncology outpatient clinics in a medical centre in southern Taiwan. Methods CML patients who regularly attended the oncology outpatient clinics to receive imatinib treatment from October 2011 to March 2012 were invited to participate in the study. Semi-structured face-to-face interviews were used to explore patients’ experiences and views of their treatment, their current CML status and CML-related health conditions, their concerns about imatinib treatment and imatinib-taking behaviours. Patient interviews were recorded, transcribed verbatim and thematically analysed using the constant comparison approach. Main outcome measure Themes related to patients’ views of the disease and health conditions, worries and concerns influencing imatinib utilisation behaviours are reported. Results Forty-two CML patients participated in the interviews. The emerging themes included: acceptance of current disease and health status, misconceptions about disease progression, factors associated with adherence to imatinib, concerns and management of adverse drug effects. Participants regarded CML as a chronic disease but had misconceptions about disease progression, therapeutic monitoring, resistance to imatinib and symptoms of side effects. Participants were generally adherent to imatinib and favoured long-term prescriptions to avoid regular outpatient visits for medication refills. Experiencing adverse effect was the main reason influencing adherence and led to polypharmacy. Most participants altered medicine-taking behaviours to maintain long-term use of imatinib. Conclusion Taiwanese CML patients are adherent to imatinib but report changing their medication-taking behaviour due to adverse drug effects and associated polypharmacy. Patients’ misconceptions of the disease and medication suggests that it is necessary to improve communication between patients and healthcare professionals. Routinely providing updated information as part of the patient counselling process should be considered as a means of improving this communication
Transcranial direct current stimulation over multiple days improves learning and maintenance of a novel vocabulary
Introduction: Recently, growing interest emerged in the enhancement of human potential by means of non-invasive brain stimulation. In particular, anodal transcranial direct current stimulation (atDCS) has been shown to exert beneficial effects on motor and higher cognitive functions. However, the majority of transcranial direct current stimulation (tDCS) studies have assessed effects of single stimulation sessions that are mediated by transient neural modulation. Studies assessing the impact of multiple stimulation sessions on learning that may induce long-lasting behavioural and neural changes are scarce and have not yet been accomplished in the language domain in healthy individuals
Recommended from our members
A survey of shipping finance research: setting the future research agenda
Financing shipping related investment projects has always been a focal area of debate and research within the international maritime industry since access to funding can determine the competitiveness of a capital-intensive business as well as its success or failure under adverse market conditions. This paper provides, for the first time, a comprehensive and structured survey of all published research in the area of shipping finance and investment. The review spans approximately four decades (1979-2018) of empirical evidence, including 162 studies published in 48 scholarly journals, complemented with select books and book chapters. The study provides a bibliometric analysis and comprehensive synthesis of existing research offering an invaluable source of information for both the academic community and business practice, shaping the future research agenda in shipping finance and investment
Reprint of "The impact of mergers and acquisitions on shareholders' wealth in the logistics service industry"
Logistic service providers are facing significant challenges in recent years due to intensified competition and ever-increasing customer expectations for cohesive high-standard services at low cost. To cope with these developments many companies aim for external growth to realize operational efficiencies and exploit productive opportunities of new markets and diversified services. Accordingly, 2015 has even become the most active year for mergers and acquisitions in logistic service industry. However, studies examining the post-merger performance effect and its determinants are scarce. Consequently, this paper takes up this issue by analysing a sample of 826 transaction announcements taken place between 1996 and 2015 and their performance effect in terms of short- and long-term abnormal shareholder returns. The results reveal, that although overall transactions exhibit significant positive abnormal returns, post-merger performance for the acquiring companies differs considerably according to the logistic services offered. In the short-term trucking, railway, 3PL and air cargo companies experience significant positive abnormal returns of about 0.6%-2.6%, while sea freight carriers realize only marginal effects and CEP companies do even not show any significant reaction. In the long-term, railway and 3PL companies realize a significant abnormal return of about 20%-24%, while trucking, sea freight and air cargo carriers do not exhibit significant returns and CEP companies do even experience significant losses of about -17%. Overall, diversifying transactions of established full-service providers outperform focus-increasing transactions of specialized operators
Projekt EMMA : Handlungsempfehlung für die Diagnostik Schädel-Hirn-Trauma induzierter Sprachstörungen : ein Explorativer Mixed-Methods Ansatz
Lucia Ransmayr, Nina Maas, Christina Leitinger, Susann May, Robert DarkowVersion of recor
- …
