Interactions of Deep-Sea Vent Invertebrates with Their Environment: The Case of Rimicaris exoculata

The vent shrimp Rimicaris exoculata thrives around many hydrothermal vent sites along the Mid-Atlantic Ridge (MAR), where it aggregates into dense swarms. In contrast to hydrothermal vent fields at the East Pacific Rise (EPR), where the biomass is dominated by tubeworms, clams, and mussels, this shrimp is one of the major animal species at MAR vents. These animals are found in the dynamic mixing interface between cold oxygenated seawater and hot, reduced hydrothermal vent fluid. The adaptation of this shrimp to the hostile deep-sea hydrothermal environment and its survival strategy has been investigated since their discovery at the TAG site in the late 1980s. Rimicaris exoculata is now known to colonize black smoker complexes along the MAR in the depth-range of 2,300-3,900 in (Rainbow, Broken Spur, TAG, Snake Pit, Logatchev, 5 degrees S (Rimicaris of exoculata). Although the presence of the Rimicaris genus was first believed to be restricted to the MAR, a related species, Rimicaris kairei, was found recently at the Central Indian Ridge (CIA) (Edmonds and Kairei vent field). This review summarizes the current knowledge of Rimicaris shrimp, focusing on their spatial and temporal distribution, chemical and thermal environment, as well as on possible nutrition strategies and behavioral aspects. Recent studies suggested that iron oxide encrusted bacteria hosted in the branchial chamber of R. exoculata from the Rainbow vent field (MAR) might rely on iron oxidation. Striking results on the occurrence and morphology of iron precipitates, as well as on bacterial-mineral interaction in the gill chamber, have lead to the hypothesis of an iron-based symbiosis between bacteria and the shrimp. Special attention is called to these issues

Kontinuierliches Lernen in universitären Massenveranstaltungen. Am Beispiel von wöchentlichen Hausaufgaben in einem volkswirtschaftlichen Grundlagenmodul

Mit der Einführung der Bachelor- und Masterstudiengänge haben sich die Anforderungen an das Studium für Studierende geändert. Neben intendierten Vorteilen der Studienreform bergen die veränderten Rahmenbedingungen auch einige Herausforderungen und Probleme für das Lernen der Studierenden. Notendruck und eine höhere Prüfungsdichte werden ergänzt durch lernstrategische Herausforderungen in der Studieneingangsphase und zusätzlich verschärft durch Konsequenzen, die sich aus vorwiegend dozentenzentrierter Lehre in Massenveranstaltungen ergeben. Das Lernen der Studierenden ist geprägt durch eine Prüfungsfixierung, Auswendiglernen auf den „letzten Drücker“, eine Konsumhaltung und mangelnde Selbstverantwortung für den eigenen Lernprozess. Die Studierenden empfinden eine subjektiv hohe Belastung, allerdings ist der Workload im Vergleich zu vor und nach der Reform nahezu unverändert. Die Dissertation beschäftigt sich mit der Workload-Thematik, insbesondere im Selbststudium. Obwohl es bereits viele Workload-Studien im hochschulischen Kontext gibt, die meist Zusammenhänge zwischen Workload und Lernerfolg bzw. Lernstrategien und Lernerfolg untersuchen, mangelt es weiterhin an Untersuchungen über unterschiedliche Lernzeitverteilungen und deren Auswirkungen auf den Lernerfolg der Studierenden. Ausgangspunkt für eine Differenzierung von Lernzeitverteilungen ist die These, dass kontinuierlich Lernende im Gegensatz zu diskontinuierlich Lernenden bei insgesamt gleichem Workload einen besseren Lernerfolg erzielen. Die Förderung von kontinuierlichem Lernen wird in der Dissertation somit als Ansatz zur Begegnung der o.g. Probleme und Herausforderungen gewählt. Neben einer theoretischen und empirischen Auseinandersetzung mit kontinuierlichem Lernen wird konkret ein Fallbeispiel der Wirtschafts- und Sozialwissenschaftlichen Fakultät analysiert, indem Hausaufgaben als Instrument zum kontinuierlichen Lernen implementiert wurden. Im Ergebnis stehen somit nicht nur Erkenntnisse zum kontinuierlichen Lernen, sondern auch der Beitrag von Hausaufgaben in diesem Kontext

Hemoglobin Mass and Blood Volume in Patients With Altitude-Related Polycythemia

Patients with chronic mountain sickness (CMS) have a high hemoglobin concentration [Hb] due to increased hemoglobin mass (Hbmass) and possibly reduced plasma volume (PV). The values of Hbmass, PV and blood volume (BV) have been described differently, and the relationships between [Hb] and Hbmass or PV are poorly understood. This study obtained representative Hbmass, PV and BV data from healthy, high-altitude residents and CMS patients and quantified the dependency of [Hb] on Hbmass and PV. Methods: Eighty-seven subjects born at high altitude (∼3,900 m) were enrolled. Thirty-four had CMS (CMS), 11 had polycythemia without CMS (intermediate, IM), 20 were healthy highlanders (HH), and 22 living near sea level (SL, 420 m) served as the sea level (SL) control group. Hbmass, PV and BV were determined using a CO-rebreathing method modified for assessing polycythemia patients. Furthermore, [Hb], hematocrit (Hct), plasma erythropoietin concentration [EPO] and blood gas and acid–base status were determined. Results: In the HH group, Hbmass was 27% higher (940 ± 105 g) than in the SL group (740 ± 112 g) and 72% (1,617 ± 265 g) lower than in the CMS group. The PV in the HH group was similar to that in the SL group (−6%) and 15% higher than that in the CMS group (p < 0.001). In the HH group, the BV (5,936 ± 673 ml) did not differ from that in the SL group and was 28% lower than in the CMS group (7,606 ± 1075 ml, p < 0.001). Log [EPO] was slightly increased in the CMS group relative to the HH group (p < 0.01). All values in the IM group were between those in the HH and CMS groups. Hbmass and BV were positively correlated, and PV was negatively correlated with peripheral O(2) saturation. Increased Hbmass and decreased PV contributed approximately 65 and 35%, respectively, to the difference in [Hb] between the HH (17.1 ± 0.8 g/dl) and CMS (22.1 ± 1.0 g/dl) groups. Conclusions: In CMS patients, the decrease in PV only partially compensated for the substantial increase in Hbmass, but it did not prevent an increase in BV; the decrease in PV contributed to an excessively high [Hb]

'Flying high?'-Jump from a height in a 'Spice' high? : A case report on the synthetic cannabinoid 5F-MDMB-P7AICA

Regarding the high potency of synthetic cannabinoids (SC), many intoxications and fatal cases are reported in literature. Here, we report on a fatality with 5F-MDMBP7AICA contributing to the occurrence of death. A 31-year-old man died 10 h after he fell from the rooftop of a house. Police investigations revealed that he had consumed a ‘legal high’ herbal blend some hours earlier. An initial toxicological screening for new psychoactive substances (NPS) was negative. One year after, the analysis of confiscated drug samples revealed the SC 5F-MDMB-P7AICA being unknown at the time of the first investigations. Hence, post-mortem specimens were retrospectively analysed for 5F-MDMB-P7AICA and its dimethylbutanoic acid (DBA) metabolite. Lung, liver, kidney and bile fluid (BF) of the decedent were analysed following solidphase extraction and standard addition, heart blood (HB) and peripheral blood (PB) by fully validated liquid–liquid extraction and protein precipitation methods. Additionally, hair specimens were analysed to examine a possible chronic consumption of the SC. All specimens were analysed by liquid–chromatography tandem mass spectrometry. 5F-MDMB-P7AICA was detected in HB (0.69 ng/ml), PB (1.2 ng/ml) and hair. DBA was found in HB (46 ng/ml) and PB (5.7 ng/ml) and could additionally be identified in liver and kidney (approximately 4–5 ng/g), lung (approximately 12 ng/g) and BF (approximately 60 ng/g). Compared with the parent compound, much higher concentrations of DBA were quantified. This case shows that drugs found at the scene can provide helpful initial information for further toxicological screenings in biological samples, especially when there is evidence of NPS consumption

Effect of Exercise-Induced Reductions in Blood Volume on Cardiac Output and Oxygen Transport Capacity

We wanted to demonstrate the relationship between blood volume, cardiac size, cardiac output and maximum oxygen uptake ([Formula: see text] O(2max)) and to quantify blood volume shifts during exercise and their impact on oxygen transport. Twenty-four healthy, non-smoking, heterogeneously trained male participants (27 ± 4.6 years) performed incremental cycle ergometer tests to determine [Formula: see text] O(2max) and changes in blood volume and cardiac output. Cardiac output was determined by an inert gas rebreathing procedure. Heart dimensions were determined by 3D echocardiography. Blood volume and hemoglobin mass were determined by using the optimized CO-rebreathing method. The [Formula: see text] O(2max) ranged between 47.5 and 74.1 mL⋅kg(–1)⋅min(–1). Heart volume ranged between 7.7 and 17.9 mL⋅kg(–1) and maximum cardiac output ranged between 252 and 434 mL⋅kg(–1)⋅min(–1). The mean blood volume decreased by 8% (567 ± 187 mL, p = 0.001) until maximum exercise, leading to an increase in [Hb] by 1.3 ± 0.4 g⋅dL(–1) while peripheral oxygen saturation decreased by 6.1 ± 2.4%. There were close correlations between resting blood volume and heart volume (r = 0.73, p = 0.002), maximum blood volume and maximum cardiac output (r = 0.68, p = 0.001), and maximum cardiac output and [Formula: see text] O(2max) (r = 0.76, p < 0.001). An increase in maximum blood volume by 1,000 mL was associated with an increase in maximum stroke volume by 25 mL and in maximum cardiac output by 3.5 L⋅min(–1). In conclusion, blood volume markedly decreased until maximal exhaustion, potentially affecting the stroke volume response during exercise. Simultaneously, hemoconcentrations maintained the arterial oxygen content and compensated for the potential loss in maximum cardiac output. Therefore, a large blood volume at rest is an important factor for achieving a high cardiac output during exercise and blood volume shifts compensate for the decrease in peripheral oxygen saturation, thereby maintaining a high arteriovenous oxygen difference

Clock monitoring is associated with age-related decline in time-based prospective memory

In laboratory time-based prospective memory tasks, older adults typically perform worse than younger adults do. It has been suggested that less frequent clock checking due to problems with executive functions may be responsible. We aimed to investigate the role of clock checking in older adults’ time-based prospective memory and to clarify whether executive functions would be associated with clock checking and consequently, with time-based prospective memory. We included 62 healthy older adults (62-85 years of age) and applied tasks of time-based prospective memory as well as of executive functions (i.e., inhibition, fluency, and working memory). We used mediation analysis to test whether time-based prospective memory declined with advancing age due to less frequent clock checking. In addition, we tested whether there would be an association between executive functions and clock checking or time-based prospective memory. Time-based prospective memory declined with advancing age due to less frequent clock checking within 30s prior to intention completion. We only found a link between executive functions and clock checking (or time-based prospective memory) when not controlling for age. Our results support the importance of clock checking for time-based prospective memory and add to the current literature that older adults’ prospective memory declines because they are less able to adapt their clock checking. Yet, the reason why older adults are less able to adapt their clock checking still remains open. Our results do not indicate that executive function deficits play a central role

"Scalping" in the context of criminal dismemberment and mutilation-a case report and review of the literature

We report on a case of criminal dismemberment and attempted scalping of a homicide victim with a “Mohawk” haircut. Case fndings are presented. A review of the literature was performed for scalping in its historical and cultural context and particularly in criminal dismemberment and mutilation: Historically, scalping was prevalent in many ancient cultures around the world, where scalps were taken as trophies or “proof of kill”, much like shrunken heads, trophy skulls, and other artefacts. Scalping was particularly widespread in Northern America in the context of tribal warfare, both before and after colonization. The iconic “Mohawk” haircut is closely linked with scalping, as it was meant to taunt the enemy. In the modern forensic context, scalping constitutes a form of criminal mutilation. However, cases of criminal dismemberment and mutilation are rare in forensic casework. Our literature review revealed a low number of scalping in criminal dismemberment and mutilation cases. The documentation was overall poor. Positioning scalping within the classifcation of criminal mutilation and dismemberment was difcult. In literature, even though case numbers were small, the majority of “textbook scalping” cases were German. The presented case, to our best knowledge, is the frst modern-day photo-documented case of (attempted) scalping, even more so of a person wearing a “Mohawk”

The green brand: Explicit and implicit framing effects of ecolabelling on brand knowledge

An increasing number of brands rely on ecolabelling as associative branding strategy for communicating their sustainability performance. Specifically, associative branding aims to link a brand to an ecolabel to embed sustainability into brand knowledge to provide an added value for consumers. In this regard, the present study applies a combined measurement approach that examines both implicit and explicit information processing to assess consumers’ brand associations related to sustainability. Specifically, a pre/post-testing is conducted to evaluate the framing effect of ecolabel exposure in a brand advertisement on the enhancement of brand knowledge. The results of the current study provide evidence that in particular implicit brand sustainability is a favorable brand association that positively affects consumers’ decision-making and preferences. Furthermore, the results reveal a relevant framing effect of ecolabelling on the enhancement of brand knowledge, on both implicit and explicit levels. In addition, the study results indicate the existence of three efficacy parameters that influence brand knowledge transfer: adequate ecolabel-brand fit, early ecolabel recognition time, and distinct implicit-explicit knowledge acquisition