Microscale mapping of alteration conditions and potential biosignatures in basaltic-ultramafic rocks on early Earth and beyond

Subseafloor environments preserved in Archean greenstone belts provide an analogue for investigating potential subsurface habitats on Mars. The c. 3.5-3.4 Ga pillow lava metabasalts of the mid-Archean Barberton greenstone belt, South Africa, have been argued to contain the earliest evidence for microbial subseafloor life. This includes candidate trace fossils in the form of titanite microtextures, and sulfur isotopic signatures of pyrite preserved in metabasaltic glass of the c. 3.472 Ga Hooggenoeg Formation. It has been contended that similar microtextures in altered martian basalts may represent potential extraterrestrial biosignatures of microbe-fluid-rock interaction. But despite numerous studies describing these putative early traces of life, a detailed metamorphic characterization of the microtextures and their host alteration conditions in the ancient pillow lava metabasites is lacking. Here, we present a new nondestructive technique with which to study the in situ metamorphic alteration conditions associated with potential biosignatures in mafic-ultramafic rocks of the Hooggenoeg Formation. Our approach combines quantitative microscale compositional mapping by electron microprobe with inverse thermodynamic modeling to derive low-temperature chlorite crystallization conditions. We found that the titanite microtextures formed under subgreenschist to greenschist facies conditions. Two chlorite temperature groups were identified in the maps surrounding the titanite microtextures and record peak metamorphic conditions at 315 ± 40°C (XFe3+(chlorite) = 25-34%) and lower-temperature chlorite veins/microdomains at T = 210 ± 40°C (lower XFe3+(chlorite) = 40-45%). These results provide the first metamorphic constraints in textural context on the Barberton titanite microtextures and thereby improve our understanding of the local preservation conditions of these potential biosignatures. We suggest that this approach may prove to be an important tool in future studies to assess the biogenicity of these earliest candidate traces of life on Earth. Furthermore, we propose that this mapping approach could also be used to investigate altered mafic-ultramafic extraterrestrial samples containing candidate biosignatures.

Atmospheric water parameters measured by a ground-based microwave radiometer and compared with the WRF model

The microwave radiometer TROWARA measures integrated water vapour (IWV) and integrated cloud liquid water (ILW) at Bern since 1994 with a time resolution of 7 s. In this study, we compare TROWARA measurements with a simulation of summer 2012 in Switzerland performed with the Weather Research and Forecasting (WRF) model. It is found that the WRF model agrees very well with TROWARA’s IWV variations with a mean bias of only 0.7 mm. The ILW distribution of the WRF model, although similar in shape to TROWARA’s distribution, overestimates the fraction of clear sky periods (83% compared to 60%).

Sentinel lymph node biopsy in thick malignant melanoma: A 16-year single unit experience.

BACKGROUND The role of sentinel lymph node biopsy (SLNB) and its benefits in patients with thick melanoma is still controversial. OBJECTIVES We evaluated the clinical effect of SLNB in patients with thick melanoma. METHODS We performed a retrospective cohort review (1996-2012) of thick melanomas. Collected data included the patient and tumour characteristics. Locoregional recurrence, distant metastases, disease free and overall survival were compared between the patients with positive and negative SLNB. RESULTS 126 thick melanomas with a mean age of 64.09 years were included in the study. Positive SLNB were found in 47 (37.3%) patients. Significantly more locoregional recurrence (P = 0.002) and distant metastases (P = 0.030) were detected in the patients with positive SLNB. Furthermore, the patients with negative SLNB showed significantly better disease free survival (P = 0.021). CONCLUSIONS Positive SLNB might be prognostic factor in thick melanoma and aggravates the outcome of thick melanomas.

Three-dimensional culture and characterization of mononuclear cells from human bone marrow

BACKGROUND AIMS The diverse phenotypic changes and clinical and economic disadvantages associated with the monolayer expansion of bone marrow-derived mesenchymal stromal cells (MSCs) have focused attention on the development of one-step intraoperative cells therapies and homing strategies. The mononuclear cell fraction of bone marrow, inclusive of discrete stem cell populations, is not well characterized, and we currently lack suitable cell culture systems in which to culture and investigate the behavior of these cells. METHODS Human bone marrow-derived mononuclear cells were cultured within fibrin for 2 weeks with or without fibroblast growth factor-2 supplementation. DNA content and cell viability of enzymatically retrieved cells were determined at days 7 and 14. Cell surface marker profiling and cell cycle analysis were performed by means of multi-color flow cytometry and a 5-ethynyl-2'-deoxyuridine incorporation assay, respectively. RESULTS Total mononuclear cell fractions, isolated from whole human bone marrow, was successfully cultured in fibrin gels for up to 14 days under static conditions. Discrete niche cell populations including MSCs, pericytes and hematopoietic stem cells were maintained in relative quiescence for 7 days in proportions similar to that in freshly isolated cells. Colony-forming unit efficiency of enzymatically retrieved MSCs was significantly higher at day 14 compared to day 0; and in accordance with previously published works, it was fibroblast growth factor-2-dependant. CONCLUSIONS Fibrin gels provide a simple, novel system in which to culture and study the complete fraction of bone marrow-derived mononuclear cells and may support the development of improved bone marrow cell-based therapies.

Sportmotorische Leistungsfähigkeit und schulische Leistung – Zum mediierenden Effekt der exekutiven Funktionen

Introduction: Da die exekutiven Funktionen in enger Verbindung mit schulischer Leistung stehen (Diamond, 2007) interessiert aus sportwissenschaftlicher Sicht, welchen Beitrag Sport und Bewegung zu dessen Erhöhung leisten kann. Direkte Zusammenhänge zwischen den Konstrukten sportmotorische Leistungsfähigkeit, exekutive Funktionen und schulische Leistung scheinen empirisch hinreichend belegt. Offen bleibt hingegen wie sich der Zusammenhang gestaltet wobei des Öfteren Mediations- und Moderationseffekte diskutiert (Alfermann & Linde, 2012), selten jedoch statistisch getestet werden. Ob die exekutiven Funktionen als potentieller Mediator zwischen sportmotorischer Leistungsfähigkeit und schulischer Leistung fungiert, ist Gegenstand des vorliegenden Beitrags. Methods: Im Rahmen der Studie „Sport und Kognition“ (SpuK) wurden insgesamt 110 Schülerinnen und Schüler (56.8% ♀; 7.90±0.43 Jahre) in ihren exekutiven Funktionen (EF) getestet. Zusätzlich wurde die sportmotorische Leistungsfähigkeit (SMLF) und die schulische Leistung (SL) durch Einschätzung der Lehrperson erhoben. Um die Annahme zu prüfen, ob die schulische Leistung vorwiegend mediiert über die exekutiven Funktionen durch die sportmotorische Leistung vorhergesagt werden kann, wurde eine Mediatoranalyse (Fairchild & McQuillin, 2010) berechnet. Results: Das Strukturgleichungsmodell mit 2(7, N=95)=3.057, p=.880; CFI>.99 weist eine hohe Anpassungsgüte auf. Erwartungsgemäss gibt es innerhalb des Mediationsmodells keinen signifikanten Zusammenhang zwischen SMLF und SL (Sprache) (β=-.12, p=.869). Während der Zusammenhang von SMLF auf EF signifikant ausfällt (β=.69, p= .026), zeigt sich der Zusammenhang von EF auf SL (Sprache) als nicht signifikant (β=.68, p=.515). Daher zeigt sich weder der direkte Effekt (p=.124) von SMLF auf SL noch der indirekte Effekte (p=.472) von SMLF auf SL über EF signifikant. Die geprüfte Mediation muss somit verworfen werden. Discussion/Conclusion: Obwohl starke Zusammenhänge von SMLF und EF als auch von EF und SL (Sprache) und gleichzeitig ein schwacher direkter Zusammenhang von SMLF und SL die theoretische Annahme der Mediation stützen, kann der indirekte Effekt keine Signifikanz ausweisen, was zu einer Ablehnung der Mediationshypothese führt. Erklären lässt sich dieser Befund durch eine zu geringfügige Stichprobe einerseits und durch eine unzureichende Datenqualität aufgrund inadäquat operationalisierter Messmethoden zur Einschätzung der schulischen Leistung andererseits. Zukünftige Studien sollten zur Messung der schulischen Leistung auf objektive Messmethoden zurückgreifen. References: Alfermann, D., & Linde, K. (2012). Physische Aktivität und kognitive Leistungsfähigkeit. In R. Fuchs & W. Schlicht (Hrsg.), Seelische Gesundheit und sportliche Aktivität (S.294-314). Göttingen: Hogrefe. Diamond, A., Barnett, W. S., Thomas, J., & Munro, S. (2007). Preschool program improves cognitive control. Science, 318, 1387-1388. Fairchild, A. J., & McQuillin, S. D. (2010). Evaluating mediation and moderation effects in school psychology: A presentation of methods and review of current practice. Journal of School Psychology, 48, 53-84.

Who cares about my feature request?

Previous studies on issue tracking systems for open source software (OSS) focused mainly on requests for bug fixes. However, requests to add a new feature or an improvement to an OSS project are often also made in an issue tracking system. These inquiries are particularly important because they determine the further development of the software. This study examines if there is any difference between requests of the IBM developer community and other sources in terms of the likelihood of successful implementation. Our study consists of a case study of the issue tracking system BugZilla in the Eclipse integrated development environment (IDE). Our hypothesis, which was that feature requests from outsiders have less chances of being implemented, than feature requests from IBM developers, was confirmed.

Causes of keel bone damage and their solutions in laying hens

Keel bone damage (KBD) is a critical issue facing the contemporary laying hen industry due to the likely pain leading to compromised welfare and reduced productivity. Recent reports suggest that KBD, while highly variable and likely dependent on a host of factors, extends to all housing systems (including traditional battery cages, furnished cages and non-cage systems), genetic lines, and management styles. Despite the extent of the problem, the research community remains uncertain as to the causes and influencing factors of KBD. To combat these issues, the current review was produced following discussions from the 1st International Keel Bone Damage Workshop held in Switzerland in April 2014. This exercise sought to assess current knowledge, foster novel collaborations, propose unique methodologies and highlight the key areas where innovative research is needed. The following paper is based on the content of those discussions and presents nine recommendations for future research efforts.