Performance-Analyse und -Optimierung in der Softwareentwicklung

Nicht-funktionale Anforderungen an ein Softwaresystem beschreiben Aspekte, die nicht direkt die Funktionalit?t, wie sie der Benutzer sieht, betreffen.     

The use of dogs as second species in regulatory testing of pesticides. I. Interspecies comparison

The relevance of studies in dogs on regulatory testing of pesticides was examined retrospectively using data of 216 pesticides (acaricides, fungicides, growth regulators and hormones, herbicides, insecticides, molluscicides, nematicides, rodenticides, synergists for insecticides) submitted for regulatory purposes during the past 40 years to the Federal Institute of Health Protection of Consumers and Veterinary Medicine (BgVV), the competent national authority in Germany. At first the relevance of the no-observed-effect levels (NOEL) for safety assessment was evaluated for each chemical in 4-week (subacute), 13-week (subchronic) and 52/104-week (chronic) toxicity studies carried out on dogs, rats and mice. After subchronic and chronic application of fungicides the sensitivity of rats and dogs to the toxic chemicals was quite similar. However, the dog was generally a more sensitive species to toxic effects of insecticides than rat and mouse. On the other hand the NOEL was lower in the rat than the dog in chronic studies on herbicides. When the lowest-observed-effect level (LOEL) was evaluated in animal species, the dog was the most sensitive in approximately 15% of the studies. Mice were found to be the most sensitive species only in approximately 1% of the studies on 216 pesticides. Comparison of organ specific toxicity at the LOEL in subacute studies on fungicides and herbicides revealed a poor correlation of target-specific organ toxicity across species. However, in the subchronic and chronic studies (13 and 52/104 weeks) no significant differences in species-specific organ toxicity were observed in the three species rat, mouse and dog. The only exception were haematoxic effects in chronic studies on herbicides, which were more frequent in dogs (40%) than in rats and mice (20%). The results support the established concept that studies on dogs and rats are important for the safety assessment of pesticides, while studies on mice do not provide further information, except for detection of an oncogenic potential which is a further controversial issue. Further analysis of subacute, subchronic and chronic studies in dogs should reveal if all of the studies are essential for safety assessment of pesticides.     

Toward time-resolved soft X-ray microscopy using pulsed fs-high-harmonic radiation

Coherent soft X-ray sources open the way to new capabilities in high-resolution imaging, site- and element-specific spectroscopy and biomicroscopy. In this paper we demonstrate imaging with a table-top soft X-ray microscope. By combining a laser driven high-harmonic light source, optimized for having the maximum brightness at around 100 eV, a pair of multilayer mirrors to select a narrow spectral band and acting simultaneously as a condenser and a Fresnel zone plate as microscope objective, we were able to resolve 200 nm structures of a diatom sample. Further, the pulsed nature of our X-ray source offers the possibility of time-resolved spectromicroscopy with a temporal resolution in the order of a few femtoseconds.     

Effects of different dietary intake of essential fatty acids on C20∶3ω6 and C20∶4ω6 serum levels in human adults

Four diets which differed in fatty acid composition were provided for five months each to a group of 24 healthy nun volunteers. The diets contained 54% carbohydrates, 16% proteins and 30% lipids. One-third of the lipid part remained unchanged during the whole study, and two-thirds were modified during each period. For this latter portion, one of the following dietary fats was used: sunflower oil, peanut oil, low erucic acid rapeseed (LEAR) oil or milk fats. This procedure allowed an evaluation of the effects of various amounts of dietary linoleic acid (C18∶2ω6) and alpha-linolenic acid (C18∶3ω3) on the serum level of their metabolites. A diet providing a large amount of linoleic acid (14% of the total caloric intake) resulted in low levels of dihomo-gamma-linolenic acid (C20∶3ω6) and arachidonic acid (C20∶4ω6) in serum phospholipids and cholesteryl esters. A diet providing a small amount of linoleic acid (0.6% to 1.3% of the total caloric intake) induced high levels of ω6 fatty acid derivatives. Intermediate serum levels of C20∶3ω6 and C20∶4ω6 were found with a linoleic acid supply of about 6.5% of the total caloric intake. Serum levels of ω6 metabolites were not different after two diets providing a similar supply of C18∶2ω6 (4.5% to 6.5% of the total caloric intake), although in one of them the supply of C18∶3ω3 was higher (1.5% for LEAR oil versus 0.13% for peanut oil). Under our experimental conditions (healthy human adults fed on a normo-caloric diet with 30% lipids), we tried to determine PUFA (linoleic and linolenic acid) allowances which should be recommended for adults. The aim of the study was to obtain a hypocholesterolemic or normocholesterolemic effect while keeping normal 20∶3ω6 and 20∶4ω6 serum levels which would evidence a normal linoleic acid metabolism. The amounts recommended are: linoleic acid 5 to 6% of the total calories; alpha-linolenic acid 0.5 to 1% of the total calories.     

Adjuvant chemotherapy for primary cardiac sarcomas: the IGR experience

The effect of additional treatments after surgery in patients with primary cardiac sarcoma (PCS) remains unknown. The present study aims to evaluate the benefit of chemotherapy in patients with non-metastatic cardiac sarcomas after optimal resection. Between October 1979 and December 1995, 15 patients with a median age of 45 (range 16-66) and a resected primary cardiac sarcoma [angiosarcoma (six), malignant fibrous histiocytoma (three), leiomyosarcoma (two), rhabdomyosarcoma (two), liposarcoma (one) and synoviosarcoma (one)] received a doxorubicin-containing regimen within 6 weeks of surgery. Adjuvant chemotherapy combinations included cyclophosphamide, vincristine and dacarbazine in four patients; ifosfamide in nine; methotrexate and vincristine in one; and doxorubicin alone in one patient. At present, 13 patients have relapsed (five during therapy), with a median time to progression of 10 months. Twelve patients developed local relapse, in four cases without metastatic disease. Two patients remain in complete remission 27 and 25 months after surgery. The median time to progression was shorter in patients presenting a cardiac angiosarcoma than other histological types (3 vs 14 months, P < 0.01). Twelve patients have died, with a median overall survival of 12 months. The 2-year survival rate is 26%. Survival was significantly longer for patients with completely resected tumours (22 vs 7 months; P = 0.02) and those who did not have angiosarcoma (18 vs 7 months; P = 0.04). In conclusion, post-operative conventional doxorubicin-based chemotherapy failed to modify the natural history of patients with resected cardiac sarcomas. Locoregional failure remains the main problem even after histologically complete resection. New approaches must be tested in patients with primary cardiac sarcoma.     

Noise characterization of sub-10-fs Ti:sapphire oscillators

A complete noise characterization of sub-10-fs Ti:sapphire oscillators in terms of pulse energy fluctuations, timing jitter, and the coupling between these two noise components is presented for the first time. The noise performance of a self-mode-locked mirror-dispersion-controlled (MDC) oscillator pumped by an Ar-ion laser and, alternatively, a diode-pumped laser (Millennia, Spectra Physics Inc.) is compared. The all-solid-state sub-10-fs system exhibits an excellent noise performance far superior to its Ar-ion-pumped counterpart. The root-mean-square (rms) pulse-energy fluctuation of the all-solid-state source is as low as 0.19% over the frequency range of 0.06 Hz-1.5 MHz. A coupling between energy noise and timing jitter has been observed for what is to our knowledge the first time in a passively mode-locked femtosecond Ti:sapphire laser     

Protective materials for subpicosecond Ti:sapphire lasers

The high intensities provided by short-pulse Ti:sapphire laser systems call for the utilization of appropriate eye-protecting materials. We summarize the representative results of our characterization measurements on optical filters employed for laser radiation protection. Physical effects are discussed that influence the transmission (and thus the protective properties) of the investigated materials. Potential hazard factors have been recognized and characterized. We make recommendations to the extension of the current characterization methods and illustrate the acquired information in the form of operation charts.