223 research outputs found
Origin and evolution of osmoregulatory mechanisms in blue-green algae (cyanobacteria) as a function of metabolic and structural complexity: Reflections of Precambrian paleobiology
Major accomplishments underlying the basic understanding of cyanobacterial resistance to salt tolerance and osmotic stress were made. The methodology proposed included: the tracing of the pathways of formation of osmoregulatory solutes by traditional methods involving C-14 labelled substrates; gas chromatography; amino acid analysis; X-ray analysis using scanning transmission electron microscopy; and most importantly, C-13 labelled substrates, followed by Nuclear Magnetic Resonance (NMR) spectroscopy. It was found that the cyanobacteria employ a diversity of organic, osmoregulatory solutes. Osmoregulatory solutes were found to serve four functions: adjustment of water activity, noninhibition of enzymes; lowering of K sub m of enzymes to allow functioning at normal levels when the intracellular salt accumulates, and extending the pH optimum of enzymes as intracellular pH rises due to proton-potassium ion pump action during osmoregulation. Differences in osmoregulatory solutes may, but are not always, be attributed to differences in nutritional capabilities. The mechanism of osmoregulation and concomitant salt tolerance in halophilic cyanobacteria was elucidated. The activities of betaine and S-Adenosylhomocysteine hydrolase are discussed
Funktionelle Insulintherapie (FIT) beim Typ-1-Diabetes
Zusammenfassung: Das Ziel der Insulinbehandlung bei Patienten mit Diabetes mellitus Typ 1 besteht darin, eine nahezu normoglykämische Blutzuckereinstellung unter Vermeidung von schweren Hypoglykämien zu erreichen, um einerseits die Entwicklung von mikro- und makrovaskulären Spätkomplikationen zu vermeiden und andererseits ein optimales körperliches Wohlbefinden zu ermöglichen. Die funktionelle Insulintherapie zusammen mit den heute verfügbaren kurz und lang wirksamen Analoginsulinen stellt eine Therapieoption für Patienten mit Diabetes mellitus Typ 1 dar, die dem physiologischen Insulinersatz sehr nahe kommt. Eine weitere Verfeinerung der Insulinabgabe lässt sich mit einer Insulinpumpentherapie erreichen. Die funktionelle Insulintherapie bietet dem Patienten eine größere Autonomie in der Selbstbehandlung und erheblich mehr Flexibilität in der Lebensgestaltung. Umgekehrt ist für ihre erfolgreiche Anwendung eine vermehrte und regelmäßige Blutzuckerselbstkontrolle unabdingba
Simultaneous islet-kidney vs pancreas-kidney transplantation in type 1 diabetes mellitus: a 5year single centre follow-up
Aims/hypothesis: The aim of this study was to compare the long-term outcomes—in terms of glucose control, renal function and procedure-related complications—of simultaneous islet-kidney (SIK) transplantation with those of simultaneous pancreas-kidney (SPK) transplantation in patients with type 1 diabetes mellitus. Methods: HbA1c, need for insulin, GFR and complication rate were compared between 13 recipients of SIK and 25 recipients of SPK transplants at the same institution. The mean follow-up was 41months. Results: Two primary organ non-functions occurred in the SIK group. HbA1c did not differ at any time point during follow-up in the SIK group compared with the SPK group (mean during follow-up 6.3 vs 5.9%). Similarly, kidney function over time was not different between the two groups. A higher rate of insulin independence following SPK transplantation (after 1year 96 vs 31% in the SIK group) was counterbalanced by a higher rate of serious adverse events (40% relaparotomies vs 0% in the SIK group). Conclusions/interpretation: The endogenous insulin production achieved by islet transplantation, combined with optimal insulin therapy, was sufficient for maintaining near-normal glucose levels. In terms of glucose control, islet transplantation provides results comparable to those achieved with pancreas transplantation. However, SPK results in a higher rate of insulin independence, albeit at the cost of more surgical complications. These results have led to a new paradigm in islet transplantation at our institution, where the primary goal is not insulin independence, but good glucose control and avoidance of severe hypoglycaemi
Levels of Formality in FOSS Communities
One of the aspects of Free and Open Source Software (FOSS) which may act as a significant deterrent to its adoption, is the method used to collaboratively develop the software and provide support through the use of communities. It is not until this method is examined more closely that its many advantages can be realised. The method can, however, seem very disorganised especially when compared with traditional proprietary development styles. A key difference between these two development approaches lies in the management of projects, and perhaps as a consequence, in the level of formality in the community environment. This paper presents the results of empirical survey research investigating FOSS community participants' views on the level of formality in FOSS, and the way in which this affects both development and support provision activities. The paper then concludes by analysing what can be learnt from the participant’s views
No alignment of cattle along geomagnetic field lines found
This paper presents a study of the body orientation of domestic cattle on
free pastures in several European states, based on Google satellite
photographs. In sum, 232 herds with 3412 individuals were evaluated. Two
independent groups participated in our study and came to the same conclusion
that, in contradiction to the recent findings of other researchers, no
alignment of the animals and of their herds along geomagnetic field lines could
be found. Several possible reasons for this discrepancy should be taken into
account: poor quality of Google satellite photographs, difficulties in
determining the body axis, selection of herds or animals within herds, lack of
blinding in the evaluation, possible subconscious bias, and, most importantly,
high sensitivity of the calculated main directions of the Rayleigh vectors to
some kind of bias or to some overlooked or ignored confounder. This factor
could easily have led to an unsubstantiated positive conclusion about the
existence of magnetoreception.Comment: Added electronic supplement with source dat
Architectural Rehabilitation and Conservation Processes informed by Augmented Reality
Abstract. The goal of the presented research is to explore human-machine interaction and to study how Augmented Reality (AR) may be a potential tool to inform Architectural Rehabilitation and Conservation processes. Nowadays obtaining data to inform both architecture projects and real estate investments is a very bureaucratic process. City councils technicians suffers from the same difficulties when are in fieldwork to do inspections and lack a complete sort of information. This proposal considers that the use of mobile technologies as smart phones and tablets can empower these technicians to obtain building related data. The specific goal of the study aims to develop a data model and an interface that can be made available to professionals which allows an efficiently reply to the user's needs as the system enables the gathering of updated information considering a particular building
Operational experience, improvements, and performance of the CDF Run II silicon vertex detector
The Collider Detector at Fermilab (CDF) pursues a broad physics program at
Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and
the end of operations in September 2011, the Tevatron delivered 12 fb-1 of
integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics
analyses undertaken by CDF require heavy flavor tagging with large charged
particle tracking acceptance. To realize these goals, in 2001 CDF installed
eight layers of silicon microstrip detectors around its interaction region.
These detectors were designed for 2--5 years of operation, radiation doses up
to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were
not replaced, and the Tevatron run was extended for several years beyond its
design, exposing the sensors and electronics to much higher radiation doses
than anticipated. In this paper we describe the operational challenges
encountered over the past 10 years of running the CDF silicon detectors, the
preventive measures undertaken, and the improvements made along the way to
ensure their optimal performance for collecting high quality physics data. In
addition, we describe the quantities and methods used to monitor radiation
damage in the sensors for optimal performance and summarize the detector
performance quantities important to CDF's physics program, including vertex
resolution, heavy flavor tagging, and silicon vertex trigger performance.Comment: Preprint accepted for publication in Nuclear Instruments and Methods
A (07/31/2013
Pauli's Principle in Probe Microscopy
Exceptionally clear images of intramolecular structure can be attained in
dynamic force microscopy through the combination of a passivated tip apex and
operation in what has become known as the "Pauli exclusion regime" of the
tip-sample interaction. We discuss, from an experimentalist's perspective, a
number of aspects of the exclusion principle which underpin this ability to
achieve submolecular resolution. Our particular focus is on the origins,
history, and interpretation of Pauli's principle in the context of interatomic
and intermolecular interactions.Comment: This is a chapter from "Imaging and Manipulation of Adsorbates using
Dynamic Force Microscopy", a book which is part of the "Advances in Atom and
Single Molecule Machines" series published by Springer
[http://www.springer.com/series/10425]. To be published late 201
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