Continued life test results for an ensemble of CO2 lasers

The life test results of five 16 low pressure CW CO2 lasers with a nominal output of 1 watt are presented. One laser quickly died while the remaining four lasers reached half power output at 38,000, 40,000, 40,000 and 40,000 hours respectively. These results show the potential for a 50,000 hour laser while the average life of the 16 tested lasers was 22,500 hours. It is further indicated that the cathode sputtering products, which settle on the glass walls of the cathode sleeve, form an increasingly heavy film as the laser ages

Life test results for an ensemble of CO2 lasers

The effects of cathode material, cathode operating temperature, anode configuration, window materials, and hydrogen additives on laser lifetime are determined. Internally oxidized copper and silber-copper alloy cathodes were tested. The cathode operating temperature was raised in some tubes through the use of thermal insulation. Lasers incorporating thermally insulated silver copper oxide cathodes clearly yielded the longest lifetimes-typically in excess of 22,000 hours. The use of platinum sheet versus platinum pin anodes had no observable effect on laser lifetime. Similarly, the choice of germanium, cadmium telluride, or zinc selenide as the optical window material appears to have no impact on lifetime

The effect of modern intensive monitoring in obstetrics on infant mortality and the incidence of hypoxia and acidosis

Peer Reviewe

Middle to Late Holocene vegetation history of the Upper Engadine (Swiss Alps): the role of man and fire

To reconstruct the vegetation and fire history of the Upper Engadine, two continuous sediment cores from Lej da Champfèr and Lej da San Murezzan (Upper Engadine Valley, southeastern Switzerland) were analysed for pollen, plant macrofossils, charcoal and kerogen. The chronologies of the cores are based on 38 radiocarbon dates. Pollen and macrofossil data suggest a rapid afforestation with Betula, Pinus sylvestris, Pinus cembra, and Larix decidua after the retreat of the glaciers from the lake catchments 11,000cal years ago. This vegetation type persisted until ca. 7300cal b.p. (5350b.c.) when Picea replaced Pinus cembra. Pollen indicative of human impact suggests that in this high-mountain region of the central Alps strong anthropogenic activities began during the Early Bronze Age (3900cal b.p., 1950b.c.). Local human settlements led to vegetational changes, promoting the expansion of Larix decidua and Alnus viridis. In the case of Larix, continuing land use and especially grazing after fire led to the formation of Larix meadows. The expansion of Alnus viridis was directly induced by fire, as evidenced by time-series analysis. Subsequently, the process of forest conversion into open landscapes continued for millennia and reached its maximum at the end of the Middle Ages at around 500cal b.p. (a.d.1450

Potenziale der Landwirtschaft in der Gotthardregion

Im Kontext mit der Entwicklung ländlicher Regionen weist die Produktion und Vermarktung von regionalen Lebensmittel-Spezialitäten ein erhebliches Potenzial auf. Dies konnte eine Studie der Hochschule für Agrar-, Forst- und Lebensmittelwissenschaften HAFL für die Gotthardregion aufzeigen. Diese Erkenntnis kann zudem mittels Fachliteratur gestützt werden. Bei der Produktion und dem erfolgreichen Vertrieb regionaler Lebensmittel-Spezialitäten kommt der Qualität der Produkte sowie einem glaubwürdigen Regionallabel eine hohe Bedeutung zu. Ebenso konnte die Studie ein erhebliches Potenzial für die Optimierung bestehender und das Auffinden neuer Absatzkanäle innerhalb und ausserhalb der Gotthardregion identifizieren. In diesem Zusammenhang kommt auch agrotouristischen Dienstleistungen eine grosse Bedeutung zu. Ein gut entwickeltes Angebot im Agrotourismus fördert nicht nur den Absatz regionaler Lebensmittel-Spezialitäten. Auch die gesamte touristische Attraktivität, die regionale Wertschöpfung der Gotthardregion und das Einkommen von Landwirtschaftsbetrieben kann damit gesteigert werden

Neural correlates of working memory and its association with metabolic parameters in early-treated adults with phenylketonuria.

BACKGROUND Phenylketonuria (PKU) is an inborn error of metabolism affecting the conversion of phenylalanine (Phe) into tyrosine. Previous research has found cognitive and functional brain alterations in individuals with PKU even if treated early. However, little is known about working memory processing and its association with task performance and metabolic parameters. The aim of the present study was to examine neural correlates of working memory and its association with metabolic parameters in early-treated adults with PKU. METHODS This cross-sectional study included 20 early-treated adults with PKU (mean age: 31.4 years ± 9.0) and 40 healthy controls with comparable age, sex, and education (mean age: 29.8 years ± 8.2). All participants underwent functional magnetic resonance imaging (fMRI) of working memory to evaluate the fronto-parietal working memory network. Fasting blood samples were collected from the individuals with PKU to acquire a concurrent plasma amino acid profile, and retrospective Phe concentrations were obtained to estimate an index of dietary control. RESULTS On a cognitive level, early-treated adults with PKU displayed significantly lower accuracy but comparable reaction time in the working memory task compared to the control group. Whole-brain analyses did not reveal differences in working memory-related neural activation between the groups. Exploratory region-of-interest (ROI) analyses indicated reduced neural activation in the left and right middle frontal gyri and the right superior frontal gyrus in the PKU group compared to the control group. However, none of the ROI analyses survived correction for multiple comparisons. Neural activation was related to concurrent Phe, tyrosine, and tryptophan concentrations but not to retrospective Phe concentrations. CONCLUSION In early-treated adults with PKU, cognitive performance and neural activation are slightly altered, a result that is partly related to metabolic parameters. This study offers a rare insight into the complex interplay between metabolic parameters, neural activation, and cognitive performance in a sample of individuals with PKU

An End-to-End Approach for Recognition of Modern and Historical Handwritten Numeral Strings

An end-to-end solution for handwritten numeral string recognition is proposed, in which the numeral string is considered as composed of objects automatically detected and recognized by a YoLo-based model. The main contribution of this paper is to avoid heuristic-based methods for string preprocessing and segmentation, the need for task-oriented classifiers, and also the use of specific constraints related to the string length. A robust experimental protocol based on several numeral string datasets, including one composed of historical documents, has shown that the proposed method is a feasible end-to-end solution for numeral string recognition. Besides, it reduces the complexity of the string recognition task considerably since it drops out classical steps, in special preprocessing, segmentation, and a set of classifiers devoted to strings with a specific length

Purification and Reconstitution of the Glutamate Carrier GltT of the Thermophilic Bacterium Bacillus stearothermophilus

An affinity tag consisting of six adjacent histidine residues followed by an enterokinase cleavage site was genetically engineered at the N-terminus of the glutamate transport protein GltT of the thermophilic bacterium Bacillus stearothermophilus. The fusion protein was expressed in Escherichia coli and shown to transport glutamate. The highest levels of expression were observed in E. coli strain DH5α grown on rich medium. The protein could be purified in a single step by Ni2+-NTA affinity chromatography after solubilization of the cytoplasmic membranes with the detergent Triton X100. Purified GltT was reconstituted in an active state in liposomes prepared from E. coli phospholipids. The protein was reconstituted in detergent-treated preformed liposomes, followed by removal of the detergent with polystyrene beads. Active reconstitution was realized with a wide range of Triton X100 concentrations. Neither the presence of glycerol, phospholipids, nor substrates of the transporter was necessary during the purification and reconstitution procedure to keep the enzyme in an active state. In B. stearothermophilus, GltT translocates glutamate in symport with protons or sodium ions. In membrane vesicles derived from E. coli cells expressing GltT, the Na+ ion dependency seems to be lost, suggesting a role for the lipid environment in the cation specificity. In agreement with the last observation, glutamate transport catalyzed by purified GltT reconstituted in E. coli phospholipid is driven by an electrochemical gradient of H+ but not of Na+.

An Efficient Ligation Method in the Making of an in vitro Virus for in vitro Protein Evolution

The “in vitro virus” is a molecular construct to perform evolutionary protein engineering. The “virion (=viral particle)” (mRNA-peptide fusion), is made by bonding a nascent protein with its coding mRNA via puromycin in a test tube for in vitro translation. In this work, the puromycin-linker was attached to mRNA using the Y-ligation, which was a method of two single-strands ligation at the end of a double-stranded stem to make a stem-loop structure. This reaction gave a yield of about 95%. We compared the Y-ligation with two other ligation reactions and showed that the Y-ligation gave the best productivity. An efficient amplification of the in vitro virus with this “viral genome” was demonstrated