Multiple Scattering of Electromagnetic Waves by an Array of Parallel Gyrotropic Rods

We study multiple scattering of electromagnetic waves by an array of parallel gyrotropic circular rods and show that such an array can exhibit fairly unusual scattering properties and provide, under certain conditions, a giant enhancement of the scattered field. Among the scattering patterns of such an array at its resonant frequencies, the most amazing is the distribution of the total field in the form of a perfect self-similar structure of chessboard type. The scattering characteristics of the array are found to be essentially determined by the resonant properties of its gyrotropic elements and cannot be realized for arrays of nongyrotropic rods. It is expected that the results obtained can lead to a wide variety of practical applications.Comment: 5 pages, 6 figure

Allgemeine Maßnahmen zur Arbeitsbeschaffung - ein Geschäft auf Gegenseitigkeit? : zur Theorie und Empirie arbeitsmarktpolitischer Feinsteuerung

"Seit die lokalen Akteure immer stärker bei der Gestaltung von ABM initiativ werden, erweist sich eine Forschungspraxis als unvollständig, die, von der zentralen Gestaltung der Arbeitsmarktpolitik ausgehend, nur auf die Analyse der Wirkung von ABM abzielt. Die Autoren setzen demgegenüber voraus, daß die Transformation des ABM-Prozesses auch eine Erweiterung der Forschungsperspektive impliziert: von der globalen Wirkungsanalyse zur Untersuchung der Implementation im Handlungsgeflecht lokaler Arbeitsmarktakteure. Allerdings liegen bisher zu diesem Thema nur vereinzelte Fallstudien vor, deren Ergebnisse in der präsentierten Form nicht verallgemeinert werden können. Die Autoren versuchen daher, auf der Grundlage einer sekundäranalytischen Auswertung der vorliegenden Befunde sowie unter Berücksichtigung eigener Forschungsergebnisse ein theoretisches Konzept zu entwerfen, das über die Beliebigkeit isolierter Einzelstudien hinausweist und als Grundlage für die weitere Forschungspraxis dienen kann." (Autorenreferat)Arbeitsbeschaffungsmaßnahme, Wirkungsforschung - Konzeption, Arbeitsmarktpolitik, Kommunalpolitik

Digitale Bewegungsförderung und Sturzprävention in Pflegeeinrichtungen – der Status-Quo von Technikaffinität und der Bereitschaft zur Nutzung digitaler Lösungen bei Pflegepersonal [Promoting physical activity and preventing falls with digital tools in care facilities - the status quo of affinity for technology and willingness to use digital solutions among nursing home employees]

Hintergrund: Die Bedeutung der Digitalisierung im Gesundheitswesen wächst seit Jahren. Diese Studie untersucht das Ausmaß der Nutzung und Implementierung digitaler Lösungen im Bereich der Bewegungsförderung im Setting Pflege sowie die Technikaffinität und die Bereitschaft des Pflegepersonals zur Nutzung digitaler Lösungen. Ein weiterer Fokus liegt auf den Nutzungsbedingungen, die digitale Konzepte erfüllen sollten, sowie möglichen Risiken die bei der Nutzung derselbigen auftreten können. Methodik: Es wurde ein Onlinefragebogen mit quantitativen und qualitativen Fragestellungen zur Nutzungsbereitschaft und Voraussetzungen für digitale Lösungen entwickelt, unter Einbezug von zwei Fragebögen zur Technikaffinität (ATI und TA-EG). Die Pflegeeinrichtungen wurden deutschlandweit rekrutiert. Die Daten wurden qualitativ mit MAXQDA und quantitativ mit SPSS Version 27 analysiert. Ergebnisse: 200 Personen aus 15 Bundesländern nahmen an der Befragung teil. Eine flächendeckende Ausstattung mit digitalen Geräten und WLAN ist in Pflegeeinrichtungen noch nicht gegeben. Es zeigten sich signifikante Unterschiede in der Technikaffinität bezogen auf das Alter (t (198) = 3,705; p = 0,000), das Geschlecht (t (196) = -2,952; p = 0,004) und die berufliche Funktion (ATI: t (198) = 2,286; p = 0,023; TA-EG: t (198) = 2,126, p = 0,035). 47 % der Teilnehmenden haben keine Erfahrung mit digitalen Lösungen im Bereich Bewegungsförderung und Sturzprävention. Als Risiken wurden Stürze, falsche Übungsausführungen und Verringerung der sozialen Kontakte identifiziert. 65,4 % (n = 53) der Einrichtungsleitungen, und 54,6 % (n = 65) der Angestellten sind bereit eine digitale Lösung zu nutzen. Die Erwartungen beinhalteten eine gute Wirksamkeit, Individualisierungsmöglichkeiten, einfache Handhabung, sowie eine gute Alltagsintegration. Schlussfolgerung: Bei der Implementierung digitaler Lösungen muss die strukturelle, bislang wenig digitalisierte Situation von Pflegeeinrichtungen berücksichtigt werden. Die Ergebnisse zur Technikaffinität lassen darauf schließen, dass eine Bereitschaft zur Nutzung an sich vorhanden ist. Mögliche Risiken und bisherige Erfahrungen, sowie Erwartungen an digitale Lösungen müssen in die Entwicklung derselbigen einfließen, um eine langfristige Nutzung zu ermöglichen

Haematocrit is invalid for estimating red cell volume: a prospective study in male volunteers

BACKGROUND: Although haematocrit and haemoglobin value are concentrations, they are commonly used to guide clinical decisions involving red cell and plasma volumes. A study challenging this convention systematically co-determined and compared these measures. MATERIALS AND METHODS: Using a non-radioactive double-tracer technique to assess blood volume components, measurements were taken once in 46 healthy male endurance athletes. The best predictors of blood composition were derived from the first 36 athletes by automated stepwise forward selection of non-invasive metric parameters (age, weight, height, body surface area and body mass index) and the resulting formulae validated in the remaining ten volunteers. Haematocrit, haemoglobin concentration, red cell volume and plasma volume were measured again 4 weeks later in eight randomly selected volunteers. RESULTS: Red cell volume (2,282±283 mL) did not correlate with either haematocrit (0.42±0.02) or haemoglobin concentration (14.2±0.8, P>0.05, resp.), but was predictable from body surface area (red cell volume [mL]=1,547 × body surface area [m2]-723; r=.88, P<0.01). A similar accuracy was unobtainable using any potential predictor for plasma or blood volume, haematocrit or haemoglobin concentration. Red cell volume showed high intra-individual stability when measured again after 4 weeks, whereas plasma volume oscillated in both directions by up to 22%. DISCUSSION: Only red cell volume shows sufficiently stable intra- and interindividual values to be an accurate, objective indicator of normality in blood composition. The measurement technique is feasible in the outpatient setting and this parameter provides effective, robust, and readily available diagnostic information that might be useful in numerous clinical situations. Its clinical significance does, however, remain to be demonstrated

Are nursing home employees ready for the technical evolution? German-wide survey on the status quo of affinity for technology and technology interaction

Background Technological devices can support nursing home employees; however, their perspective is not sufficiently studied. Our aims were thus to (a) examine affinity for technology and technology interaction and related sociodemographic confounders, as well as (b) detect possible requirements and boundary conditions relevant for the development and implementation of assistive technologies among nursing home employees. Methods We conducted an online survey between May and July of 2022 among 200 nursing home employees in Germany. The survey included two questionnaires, that is, Affinity for Technology Interaction (ATI) and Affinity for Technology—Electronic Devices (TA-EG; subscales TA-EG-Enthusiasm, TA-EG-Competence, TA-EG-Positive Consequences, and TA-EG-Negative Consequences), as well as sociodemographic variables, that is, age, gender, professional groups, education/graduation level. We carried out factorial variance and multiple regression analyses. Results There were differences between age groups in ATI (lower score with increasing age) and between gender, age, and professional group in TA-EG (lower score for females, participants with higher ages, and nursing home managers). Predictors of ATI were age and professional group, predictors of TA-EG, TA-EG-Enthusiasm, and TA-EG-Competence were gender, age, and professional group. Predictors of TA-EG-Positive Consequences were education and professional group. Conclusions We observed rather high affinity for technology and technology interaction values overall, and particularly for nursing home employees compared to managers. Significant predictors for technology affinity and interaction may have important implications, for example the perspectives of nursing home employees and managers should be considered separately in the technological design, development, and implementation process. Furthermore, an open dialogue between all stakeholders should be encouraged to increase the probability of actual technology use

Feasibility of image-guided radiotherapy based on helical tomotherapy to reduce contralateral parotid dose in head and neck cancer

Background To evaluate the feasibility of image-guided radiotherapy based on helical Tomotherapy to spare the contralateral parotid gland in head and neck cancer patients with unilateral or no neck node metastases. Methods A retrospective review of 52 patients undergoing radiotherapy for head and neck cancers with image guidance based on daily megavoltage CT imaging with helical tomotherapy was performed. Results Mean contralateral parotid dose and the volume of the contralateral parotid receiving 40 Gy or more were compared between radiotherapy plans with significant constraint (SC) of less than 20 Gy on parotid dose (23 patients) and the conventional constraint (CC) of 26 Gy (29 patients). All patients had PTV coverage of at least 95% to the contralateral elective neck nodes. Mean contralateral parotid dose was, respectively, 14.1 Gy and 24.7 Gy for the SC and CC plans (p < 0.0001). The volume of contralateral parotid receiving 40 Gy or more was respectively 5.3% and 18.2% (p < 0.0001) Conclusion Tomotherapy for head and neck cancer minimized radiotherapy dose to the contralateral parotid gland in patients undergoing elective node irradiation without sacrificing target coverage

Agentic learning: the pedagogical implications of young trans people’s online learning strategies

This paper proposes anew conceptualisation of learning in the age of the internet, increasing systemic rigidity of formal education and intensified media manipulation and partiality. Using empirical data and drawing on Social Activity Method it elaborates the different strategies young trans people recruit in their self-learning and contends that these constitute a type of learning where the control of pedagogy, the learning environment and the subject matter lies to a significant extent, with the learner, taking place in spaces free from the influence of hegemonic transphobia. This type of learning appears to constitute an effective but complex one. As, in this instance, the learning is taking place in a wider cultural environment where the subject matter is often suppressed and subject to ideological misrepresentation by hegemonic control of the public sphere, this study suggests that learning by providing learners with greater control over pedagogy and learning environment is effective

Sildenafil attenuates pulmonary arterial pressure but does not improve oxygenation during ARDS

OBJECTIVE: Pulmonary hypertension is a characteristic feature of acute respiratory distress syndrome (ARDS) and contributes to mortality. Administration of sildenafil in ambulatory patients with pulmonary hypertension improves oxygenation and ameliorates pulmonary hypertension. Our aim was to determine whether sildenafil is beneficial for patients with ARDS. DESIGN: Prospective, open-label, multicenter, interventional cohort study. SETTING: Medical-surgical ICU of two university hospitals. PATIENTS: Ten consecutive patients meeting the NAECC criteria for ARDS. INTERVENTIONS: A single dose of 50 mg sildenafil citrate administered via a nasogastric tube. MAIN RESULTS: Administration of sildenafil in patients with ARDS decreased mean pulmonary arterial pressure from 25 to 22 mmHg (P = 0.022) and pulmonary artery occlusion pressure from 16 to 13 mmHg (P = 0.049). Systemic mean arterial pressures were markedly decreased from 81 to 75 mmHg (P = 0.005). Sildenafil did not improve pulmonary arterial oxygen tension, but resulted in a further increase in the shunt fraction. CONCLUSION: Although sildenafil reduced pulmonary arterial pressures during ARDS, the increased shunt fraction and decreased arterial oxygenation render it unsuitable for the treatment of patients with ARD

Sex and sexuality: An evolutionary view

In this article, I first offer a summary of Darwin’s main ideas, especially relating to sex, and explain how these have been elaborated by more recent evolutionary scholars. I then give an account of the historical divergence between psychoanalysis and classical Darwinian thought, and describe how the early psychoanalyst Sabina Spielrein tried to counter this by addressing some biological themes in her work. Following a review of some contemporary attempts to bring psychoanalysis and evolutionary thought into alignment with each other, I make some suggestions regarding a view of sex and sexuality that would be sound in evolutionary terms while also being helpful in psychoanalytic ones