On the determination of dynamic errors for rise time measurementwith an oscilloscope

The dynamic behavior of an oscilloscope is usually described by its bandwidth, which is not sufficient for well-founded error estimation for rise time measurement. Two rules of thumb have become most common that describe (a) a relation between bandwidth and rise time of an oscilloscope and (b) an estimation of the error resulting from the rise time limitation of the oscilloscope. Although it is well understood that these rules are approximations, no information on their accuracy and extent of validity appears in the literature. In this paper, we analyze these rules of thumb with their underlying assumptions and respect a more realistic model for oscilloscope behavior. We give accurate error estimates for a selection of typical input signals, show how well the rules perform for these signals and that, although the rules provide good upper bounds for the error, they can not be reliably used for error correction     

Liver transplantation in acute liver failure

Acute hepatic failure is characterized by jaundice and hepatic encephalopathy within eight weeks after the onset of disease. Although acute hepatic failure is a rare occurrence, its rapid progression and high mortality (50 to 90%, depending on the etiology of disease) necessitate immediate intervention. In the absence of causal therapy, orthotopic liver transplantation is currently the only definitive and effective means of treating acute hepatic failure in Europe, acute hepatic failure accounts for 11% of all liver transplantations. At the University department of transplantation surgery in Vienna a total of 27 patients with acute hepatic failure underwent 31 liver transplantations in the last 10 years (1.1.1987 to 31.12.1996). Twenty (74%) of the 27 patients survived the acute event and were discharged from hospital in good general condition after a median postoperative stay of 25 days (range 14-81 days). Seven patients (26%) died between the first and 34th postoperative day (median 26 days) in the intensive care unit, although all potential modern options of intensive care and surgery were used. The causes of death were irreversible cerebral edema (n = 3), multiple organ failure due to bacterial sepsis (n = 3) and uncontrollable haemolysis (n = 1). With a 3-year graft survival rate of 70% the 3-year patient survival rate was 74%. A retrospective analysis of our patients revealed that the postoperative graft function and the incidence of re-transplantation were significant prognostic factors (p < 0.05) for survival following orthotopic liver transplantation for acute hepatic failure. In the absence of further prognostically relevant preoperative indices and in consideration of the potentially fulminant progression of disease, we strongly recommend that any patient, in whom acute hepatic failure is suspected, is immediately transferred to a specialized center with experience both in the conservative treatment of acute hepatic failure and emergency liver transplantation.     

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FIT-IT-Projekt DARTS: dezentrale fehlertolerante Taktgenerierung

Dieser Artikel beschreibt Ziele und L?sungsansatz des pr?mierten FIT-IT-"Embedded Systems"-Projekts "Distributed Algorithms for Robust Tick Synchronization" (DARTS), das der Entwicklung einer fehlertoleranten Alternative zur herk?mmlichen Taktgenerierung in VLSI-Chips, Systems-on-Chip und anderen Hardwaresystemen gewidmet ist. Anstatt das Taktsignal eines einzelnen Oszillators mit Hilfe eines aufw?ndig balancierten Clock-Trees systemweit zu verteilen, wird in DARTS der Takt jeder Funktionseinheit mit Hilfe eines lokalen Taktgenerators erzeugt. Damit wird der "Single Point of Failure" eliminiert, den ein zentraler Oszillator zwangsl?ufig darstellt. Im Gegensatz zum klassischen "Globally Asynchronous Locally Synchronous" (GALS)-Ansatz sind die lokalen Taktgeneratoren beim DARTS-Ansatz jedoch keine Oszillatoren, sondern Instanzen eines verteilten Algorithmus zur fehlertoleranten Generierung synchronisierter lokaler Taktsignale.      

Genetic analysis of efficiency traits in Austrian dairy cattle and their relationships with body condition score and lameness

This study is part of a larger project whose overall objective was to evaluate the possibilities for genetic improvement of efficiency in Austrian dairy cattle. In 2014, a 1-yr data collection was carried out. Data from 6,519 cows kept on 161 farms were recorded. In addition to routinely recorded data (e.g., milk yield, fertility, disease data), data of novel traits [e.g., body weight (BW), body condition score (BCS), lameness score, body measurements] and individual feeding information and feed quality were recorded on each test-day. The specific objective of this study was to estimate genetic parameters for efficiency (related) traits and to investigate their relationships with BCS and lameness in Austrian Fleckvieh, Brown Swiss, and Holstein cows. The following efficiency (related) traits were considered: energy-corrected milk (ECM), BW, dry matter intake (DMI), energy intake (INEL), ratio of milk output to metabolic BW (ECM/BW^0.75), ratio of milk output to DMI (ECM/DMI), and ratio of milk energy output to total energy intake (LE/INEL, LE = energy in milk). For Fleckvieh, the heritability estimates of the efficiency (related) traits ranged from 0.11 for LE/INEL to 0.44 for BW. Heritabilities for BCS and lameness were 0.19 and 0.07, respectively. Repeatabilities were high and ranged from 0.30 for LE/INEL to 0.83 for BW. Heritability estimates were generally lower for Brown Swiss and Holstein, but repeatabilities were in the same range as for Fleckvieh. In all 3 breeds, more-efficient cows were found to have a higher milk yield, lower BW, slightly higher DMI, and lower BCS. Higher efficiency was associated with slightly fewer lameness problems, most likely due to the lower BW (especially in Fleckvieh) and higher DMI of the more-efficient cows. Body weight and BCS were positively correlated. Therefore, when selecting for a lower BW, BCS is required as additional information because, otherwise, no distinction between large animals with low BCS and smaller animals with normal BCS would be possible.     

Monitoring selected behaviors of calves by use of an ear-attached accelerometer for detecting early indicators of diarrhea

One of the most important diseases in calves worldwide is neonatal calf diarrhea (NCD), which impairs calf welfare and leads to economic losses. The aim of this study was to test whether the activity patterns of calves can be used as early indicators to identify animals at risk for suffering from NCD, compared with physical examination. We monitored 310 healthy female Holstein-Friesian calves on a commercial dairy farm immediately after birth, equipped them with an ear tag–based accelerometer (Smartbow, Smartbow GmbH), and conducted daily physical examinations during the first 28 d of life. The Smartbow system captured acceleration data indicative of standing and lying periods and activity levels (active and inactive), shown as minutes per hour. We categorized calves as diarrheic if they showed fecal scores of ≥3 on a 4-point scale on at least 2 consecutive days. Incidence of diarrhea was 50.7% (n = 148). A mixed logistic regression model showed that lying [odds ratio (OR) = 1.19], inactive (OR = 1.14), and active (OR = 0.92) times, 1 d before clinical identification of diarrhea (d ?1), were associated with the odds of diarrhea occurring on the subsequent day. Receiver operating characteristics curve showed that lying time at d ?1 was a fair predictor for diarrhea on the subsequent day (area under curve = 0.69). Average lying time on d ?1 was 64.8 min longer in diarrheic calves compared with their controls. Median lying and inactive times decreased, and active time increased with age over the study period. The 24-h pattern of behavior indices based on the output of the Smartbow system followed periods of resting and active times, and showed that between 2200 h and 0600 h, calves spent the greatest percentage of time lying and inactive. These results showed that the accelerometer system has the potential to detect early indicators associated with NCD. In future studies, additional data for the development and testing of calf- and event-specific algorithms (e.g., for detecting milk intake, playing behavior) should be collected, which might further improve the early detection of diarrhea in calves.     

Increased natural killer cell activity correlates with low or negative expression of the HER-2/neu oncogene in patients with breast cancer

BACKGROUND: Increased expression of the HER-2/neu oncogene in breast cancer correlates with decreased estrogen receptor concentration and seems to be an important prognostic factor. The authors investigated whether there is a correlation between HER-2/neu expression and immunologic parameters representing tumor defense in patients with breast cancer. METHOD: A Western blot analysis was used to investigate HER-2/neu expression, whereas a chromium-release assay using the K562 cell line as target was used to measure natural killer (NK) cell activity. RESULTS: In patients with breast cancer, NK cell activity was significantly higher compared with patients with benign tumors (P = 0.006) or healthy control subjects (P = 0.002). Moreover, 23.3% of patients with breast cancer showed an overexpression of HER-2/neu protein. Within this group of patients, NK cell activity was significantly lower (45.6 +/- 16.1%) compared with the group with no HER-2/neu overexpression (57.3 +/- 11.0%). NK cell activity did not increase in patients with HER-2/neu overexpression. Thus, there was a statistically significant correlation of cytolytic effector cell function with HER-2/neu expression of the tumor (P = 0.003), and HER-2/neu overexpression correlated with a negative estrogen receptor status (P = 0.005). CONCLUSION: These data add further evidence to previous observations from the authors' laboratory that certain tumor characteristics may be associated with reactions of the host with breast cancer.