A note on central limit theorems for quadratic variation in case of endogenous observation times

This paper is concerned with a central limit theorem for quadratic variation when observations come as exit times from a regular grid. We discuss the special case of a semimartingale with deterministic characteristics and finite activity jumps in detail and illustrate technical issues in more general situations.Comment: 16 pages, 1 figur

Use of a zeolite synthesised from alkali treated kaolin as a K fertiliser: Glasshouse experiments on leaching and uptake of K by wheat plants in sandy soil

Zeolite N, a zeolite referred to in earlier publications as MesoLite, is made by caustic reaction of kaolin at temperatures between 80 °C and 95 °C. This material has a very high cation exchange capacity (CEC ≈ 500 meq/100 g). Soil column leaching experiments have shown that K-zeolite N additions greatly reduce leaching of NH4+ fertilisers but the agronomic effectiveness of the retained K+ and NH4+ is unknown. To measure the bioavailability of K in this zeolite, wheat was grown in a glasshouse with K-zeolite N as the K fertiliser in highly-leached and non-leached pots for four weeks and compared with a soluble K fertiliser (KCl). The plants grown in non-leached pots and fertilised with K-zeolite N were slightly larger than those grown with KCl. The elemental compositions in the plants were similar except for Si being significantly more concentrated in the plants supplied with K-zeolite N. Thus K-zeolite N may be an effective K-fertiliser. Plants grown in highly-leached pots were significantly smaller than those grown in non-leached pots. Plants grown in highly-leached pots were severely K deficient as half of the K from both KCl and K-zeolite N was leached from the pots within three days

Einfluß der parenteralen Gabe von langkettigen Fettsäuren auf den Prostanoidstoffwechsel bei septischen Patienten

In der vorliegenden Studie wurde im Rahmen einer totalen parenteralen Ernährung der Einfluß von Liposyn 20%, einer Fettemulsion die aus ungesättigten langkettigen Fettsäuren, insbesondere Linolsäure besteht, auf den Eikosanoidstoffwechsel von septischen Patienten untersucht. Auf der septischen Intensivstation des Zentralklinikums Augsburg wurden eine Kurzzeit-studie und eine Langzeitstudie an septischen Patienten durchgeführt. An der Kurzzeitstudie, die über 4 Tage ging nahmen 12 Patienten teil, an der Langzeit-studie mit einer Dauer von 10 Tagen nahmen 6 Patienten teil. In jeder der beiden Studien wurde die eine Hälfte der Patienten ausschließlich mit einem Kohlenhydratgemisch ernährt, während in der anderen Gruppe 50% der Nichteiweißkalorien durch Liposyn 20% bereitgestellt wurden. Insgesamt bekamen die Patienten 30 kcal/kg Körpergewicht pro Tag an Nichteiweißkalorien parenteral verabreicht. Zusätzlich wurde in allen Gruppen den Patienten 100g Aminosäuren pro Tag gegeben. Zur Vergleichbarkeit der Patienten in Hinblick auf ihre Erkrankungsschwere untereinander wurde nachträglich bei jedem Patienten der APACHE III-Score für jeden Studientag ermittelt. In dem Eikosanoidlabor der Kinderklinik der Universität Marburg wurden mittels Gaschromatographie/Massenspektrometrie folgende Indexmetabolite der Eikosanoide gemessen: - 11-dehydro-TxB2 im Plasma (Maß für die phasische TxA2-Produktion), - TxB2 im 24h Urin (Maß für die renale TxA2-Produktion), - 2,3-dinor-TxB2 im 24h Urin (Maß für die systemische TxA2-Produktion), - 2,3-dinor-6-keto-PGF1 im 24h Urin (Maß für die systemische PGI2- Produktion), - PGE-M im 24h-Urin (Maß für die systemische PGE2-Produktion). Zusätzlich wurden die Triglyceride und Cholesterinester im Plasma, sowie der Linolsäuregehalt in den Cholesterinestern bestimmt. Unter Berücksichtigung des APACHE-Score bestanden keine wesentlichen Unterschiede in Hinblick auf die Erkrankungsschwere bei den untersuchten Patienten. Die Letalität war in der Kurzzeitstudie in der Kontrollgruppe etwas höher als in der Fettgruppe. In der Langzeitstudie war die Letalität in beiden Gruppen gleich groß. Die Triglycerid- und Cholesterinwerte lagen im Normbereich was für eine gute Elimination und Verstoffwechslung der infundierten Fettemulsion spricht. Bei allen Patienten zeigten sich stark erhöhte Eikosanoidwerte. Weder in der Kurzzeit- noch in der Langzeitstudie ließen sich deutliche Unterschiede in der Eikosanoidproduktion unter Gabe von Liposyn 20% nachweisen. Ursache hierfür scheint zu sein, dass es durch die bei der Sepsis verstärkte Lipolyse zu einer vermehrten Freisetzung von Arachidonsäure aus den Phospholipiden der Zellmembranen kommt. Dieser Anstieg an verfügbarer Arachidonsäure führte zu einer Erhöhung der Eikosanoidproduktion in beiden Gruppen. Die zusätzliche Gabe von Linolsäure führte offensichtlich jedoch nicht zu einer vermehrten Bereitstellung von Arachidonsäure in der Fettgruppe, was durch die geschwindigkeitsbestimmenden Desaturasen erklärt werden kann. Sicherlich besteht bei Zufuhr von Linolsäure über einen längeren Zeitraum auch die Möglichkeit einer vermehrten Bereitstellung von Arachidonsäure. Die in der Studie gewählten Zeiträume waren aber offensichtlich zu kurz, um dies zu bewirken. Die Ergebnisse dieser Studie zeigen somit, dass in Bezug auf die gemessenen Eikosanoide keine Gründe gegen die Verwendung von langkettigen ungesättigten Fettsäuren als Bestandteil der totalen parenteralen Ernährung für die Dauer des untersuchten Beobachtungszeitraumes sprechen

Effects of hypothermia on brain glucose metabolism in acute liver failure: a H/C-nuclear magnetic resonance study

Mild hypothermia has a protective effect on brain edema and encephalopathy in both experimental and human acute liver failure. The goals of the present study were to examine the effects of mild hypothermia (35°C) on brain metabolic pathways using combined 1H and 13C-Nuclear Magnetic Resonance (NMR) spectroscopy, a technique which allows the study not only of metabolite concentrations but also their de novo synthesis via cell-specific pathways in the brain. :1H and 13C NMR spectroscopy using [1-13C] glucose was performed on extracts of frontal cortex obtained from groups of rats with acute liver failure induced by hepatic devascularization whose body temperature was maintained either at 37°C (normothermic) or 35°C (hypothermic), and appropriate sham-operated controls. At coma stages of encephalopathy in the normothermic acute liver failure animals, glutamine concentrations in frontal cortex increased 3.5-fold compared to sham-operated controls (P < 0.001). Comparable increases of brain glutamine were observed in hypothermic animals despite the absence of severe encephalopathy (coma). Brain glutamate and aspartate concentrations were respectively decreased to 60.9% ± 7.7% and 42.2% ± 5.9% (P < 0.01) in normothermic animals with acute liver failure compared to control and were restored to normal values by mild hypothermia. Concentrations of lactate and alanine in frontal cortex were increased to 169.2% ± 15.6% and 267.3% ± 34.0% (P < 0.01) respectively in normothermic rats compared to controls. Furthermore, de novo synthesis of lactate and alanine increased to 446.5% ± 48.7% and 707.9% ± 65.7% (P < 0.001), of control respectively, resulting in increased fractional 13C-enrichments in these cytosolic metabolites. Again, these changes of lactate and alanine concentrations were prevented by mild hypothermia. Mild hypothermia (35°C) prevents the encephalopathy and brain edema resulting from hepatic devascularization, selectively normalizes lactate and alanine synthesis from glucose, and prevents the impairment of oxidative metabolism associated with this model of ALF, but has no significant effect on brain glutamine. These findings suggest that a deficit in brain glucose metabolism rather than glutamine accumulation is the major cause of the cerebral complications of acute liver failure

The Tamar Trough revisited: correlations berween sedimentary beds, basalts, their ages and valley evolution, North Tasmania

The Tamar Trough, an Early Palaeogene fault structure, contains sedimentaty beds and interleaved basaltic flows that infill the structure along its 70 km length. These infills represent a complex interplay between sedimentation, channel erosion, eruptive dislocations, and even 'out of trough' diyersions of the ancestral Tamar drainage. Several areas of resistant basalt flows remain in the south, upper, middle and lower Tamar reaches. Although some palynological control was known, radiometric dating of previously untested basalts now allows close integration and age-pegging for observed palynological biozones. The K-Ar and Ar-Ar ages of the basalt bodies indicate eruptive events at 47, 33-37 and 25 Ma, correlating with Proteacidites asperopolus-Malvacipollis diversus, Nothofagites asperus and Proteacidites tuberculatus biozone age sedimentary beds respectively. Basanite, alkali basalt and hawaiite flows dominate basalt lithology with lesser olivine nephelinite, transitional olivine basalt, olivine tholeiite and quartz tholeiite. Basalt geochemistry suggests derivation from different degrees of partial mande melting (from 7 to 35%), with alkaline and tholeiitic basalts being derived from separate source regions. Most alkaline basalts have high-jl (HIMU) related trace element signatures, which are absent in the tholeiitic rocks. A basalt plug on the trough margin at Loira gave a Jurassic age and has Jurassic dolerite-like geochemistry. The Tamar sequence suggests that the initial fluvio-Iacustrine and later channel-fill sedimentation from 65(?) to 24(?) Ma was then punctuated in places by periods of alkaline volcanism between 47 to 33(?) Ma, and alkaline and tholeiitic volcanism between 33 to 24(?) Ma. No Neogene fossils are known, so this later period was probably one of net erosion. These contrasting quiet sedimentary and more volcanic intervals are related here to a tectonic model that involves northerly drift of Victorian and Tasmanian lithosphere over several former Tasman metasomatised mantle plume sources

Selective alterations of brain osmolytes in acute liver failure: protective effect of mild hypothermia

The principal cause of mortality in patients with acute liver failure (ALF) is brain herniation resulting from intracranial hypertension caused by a progressive increase of brain water. In the present study, ex vivo high-resolution 1H-NMR spectroscopy was used to investigate the effects of ALF, with or without superimposed hypothermia, on brain organic osmolyte concentrations in relation to the severity of encephalopathy and brain edema in rats with ALF due to hepatic devascularization. In normothermic ALF rats, glutamine concentrations in frontal cortex increased more than fourfold at precoma stages, i.e. prior to the onset of severe encephalopathy, but showed no further increase at coma stages. In parallel with glutamine accumulation, the brain organic osmolytes myo-inositol and taurine were significantly decreased in frontal cortex to 63\% and 67\% of control values, respectively, at precoma stages (p<0.01), and to 58\% and 67\%, respectively, at coma stages of encephalopathy (p<0.01). Hypothermia, which prevented brain edema and encephalopathy in ALF rats, significantly attenuated the depletion of myo-inositol and taurine. Brain glutamine concentrations, on the other hand, did not respond to hypothermia. These findings demonstrate that experimental ALF results in selective changes in brain organic osmolytes as a function of the degree of encephalopathy which are associated with brain edema, and provides a further rationale for the continued use of hypothermia in the management of this condition

Outcome and predictors for successful resuscitation in the emergency room of adult patients in traumatic cardiorespiratory arrest

BACKGROUND: Data of the TraumaRegister DGU® were analyzed to derive survival rates, neurological outcome and prognostic factors of patients who had suffered traumatic cardiac arrest in the early treatment phase. METHODS: The database of the TraumaRegister DGU® from 2002 to 2013 was analyzed. The main focus of this survey was on different time points of performed resuscitation. Descriptive and multivariate analyses (logistic regression) were performed with the neurological outcome (Glasgow Outcome Scale) and survival rate as the target variable. Patients were classified according to CPR in the prehospital phase and/or in the emergency room (ER). Patients without CA served as a control group. The database does not include patients who required prehospital CPR but did not achieve ROSC. RESULTS: A total of 3052 patients from a total of 38,499 cases had cardiac arrest during the early post-trauma phase and required CPR in the prehospital phase and/or in the ER. After only prehospital resuscitation (n = 944) survival rate was 31.7 %, and 14.7 % had a good/moderate outcome. If CPR was required in the ER only (n = 1197), survival rate was 25.6 %, with a good/moderate outcome in 19.2 % of cases. A total of 4.8 % in the group with preclinical and ER resuscitation survived, and just 2.7 % had a good or moderate outcome. Multivariate logistic regression analysis revealed the following prognostic factors for survival after traumatic cardiac arrest: prehospital CPR, shock, coagulopathy, thorax drainage, preclinical catecholamines, unconsciousness, and injury severity (Injury Severity Score). CONCLUSIONS: With the knowledge that prehospital resuscitated patients who not reached the hospital could not be included, CPR after severe trauma seems to yield a better outcome than most studies have reported, and appears to be more justified than the current guidelines would imply. Preclinical resuscitation is associated with a higher survival rate and better neurological outcome compared with resuscitation in the ER. If resuscitation in the ER is necessary after a preclinical performed resuscitation the survival rate is marginal, even though 56 % of these patients had a good and moderate outcome. The data we present may support algorithms for resuscitation in the future

V.A.C.® Abdominal Dressing System: A Temporary Closure for Open Abdomen

Background and Purpose:: The study reports experience with the recently commercially available V.A.C.® Abdominal Dressing System, a system designed for a temporary closure of an open abdomen situation under negative pressure. The method allows a late primary fascial closure after laparotomy in case of damage control, abdominal compartment syndrome or severe intra-abdominal spesis and facilitates delayed reconstruction of a large ventral hernia. Patients and Methods:: 18 patients with an open abdomen after laparotomy were managed between February 2002 and September 2004. Results:: Twelve patients after primary, one patient after secondary fascial closure and one patient with partially primary closure and resorbable mesh for abdominal wall reconstruction were free of wound infection or dehiscence of the abdominal wall. Evisceration or enteric fistulas were not observed. Five patients died in consequence of severe injury, a multiple organ failure or septic complications. Conclusion:: V.A.C.® Abdominal Dressing System is an effective temporary closure technique for open abdomen in critically ill patients which makes a late primary fascial closure up to 2 months after initial laparotomy possible either in trauma patients or in case of severe intraabdominal infection. The technique is simple and easily mastere