Atmospheric Polycyclic Aromatic Hydrocarbons: An Aspect of Air Pollution in Fairbanks, Alaska

Quantitative analysis of atmospheric polycyclic aromatic hydrocarbons (PAH) in Fairbanks, Alaska revealed significant levels of representative components. A fairly constant PAH pattern was observed throughout the winter of 1976-77, and the absolute PAH level correlated with air stagnation. Consideration of relative levels of individual PAH components reveals vehicular emissions as the major source but also provides evidence for contributions from power plant emissions. Fairbanks' PAH levels approach those of major cities in more moderate climates, and this situation emphasizes the importance of air quality problems in development of the Arctic

Percutaneous angioplasty for infrainguinal graft-related stenoses

Objective:To assess the success of percutaneous transluminal angioplasty (PTA) in treating infrainguinal graft-related stenoses.Design:Retrospective analysis of stenoses undergoing PTA over 6 years.Materials:Fifty-seven stenoses in 42 grafts.Methods:Site, length and type of stenoses recorded. Follow-up till discharge, graft occlusion or death.Results:PTA was successful in 48/57 stenoses in 36 grafts (G), with a poor result in seven. Further PTA was required in seven stenoses (7 G). One graft occluded at PTA and one stenosis was inaccessible. Overall graft (G) patency (median 13 months) was 82% (1 year patency 84%). Of 48 successful PTAs (37 G), 36 remained patent (28 G), eight (4 G) occluded and four were lost to follow-up (4 G). Fourteen of thirty-six stenoses which remained patent required further intervention (seven PTA, six jump grafts, one vein patch). The four occlusions were associated with small veins (two), multiple stenoses (one) and a PTFE graft which occluded 10 days following PTA. Of the seven PTAs with a poor angiographic result, five remained patent, three after further intervention.Conclusion:PTA is the best treatment for localised stenoses. Stenoses >2 cm or multiple (three or more) stenoses are best treated surgically. Follow-up is essential, as 20% require further intervention

Nachhaltigkeit von drei graslandbasierten Milchproduktionssystemen in der Schweiz mit der Bewertungsmethode RISE

Dairy farming is a key sector for Swiss agriculture and the food industry. Therefore, sustainability of dairy farms is important. Grassland-based farming systems are the most common production system, combining the indoor feeding of fresh grass with partial grazing. The effects of three dairy production systems (VW: full grazing plus on avg. 46±93 SD kg concentrate (KF), GFKF: indoor feeding/partial grazing plus on avg. 345±204 SD kg KF and GFKFplus: indoor feeding/partial grazing plus on avg. 1007±353 SD kg KF) on sustainability, according to RISE, were studied on 12 pilot farms in the lowland of Switzerland. In most of the sustainability themes, the farms performed medium to good according to the RISE evaluation scale. The GFKFplus farms produced the highest output of milk by low N- and P-self-sufficiency, showed the highest energy input and the lowest greenhouse gas output per kg milk. The GFKF group achieved remarkable results by moderate N-, P- and energy inputs. The VW farms showed a lower milk output but a higher level of feed self-sufficiency and a lower energy consumption. In the search for the optimal production strategy, farms should consider the individual farm structure (contiguous areas), the market potential but also social aspects such as the preferences of the farmer`s family

Revisiting (some of) the Lasting Impacts of the Liberty Ships Via A Metallurgical Analysis of Rivets from the SS John W. Brown

During World War II, 2710 Liberty ships were built in the United States across 18 ship yards. The rate of production of these ships was at a scale not previously witnessed, reflecting a strategic marshaling of national assets critical to the war effort. For the metallurgist, metallurgical engineer, or materials scientist, these ships also struck commanding images regarding their catastrophic failures. The study of these failures led to increased understanding of brittle fracture, fracture mechanics, and ductile-to-brittle transition temperatures. The post-mortem studies of Liberty ships highlighted the importance of composition and microstructure in controlling the properties of steel in fracture-critical applications. This study examines a rivet from the SS “John W. Brown”, which was assembled in Baltimore, Maryland, and launched in September 1942, The “John W. Brown” was restored between 1988 and 1991. Classical metallurgical analysis of a rivet from the original 1942 vessel is compared with modern rivets used during its restoration. The rivets provide an analogue to the plate material used in these ships. A comparison of these materials is presented along with a discussion of the importance of composition–microstructure–property relationships that concomitantly evolved

Effects on performance, carcass and meat quality of replacing maize silage and concentrate by grass silage and corn-cob mix in the diet of growing bulls

Grass silage is barely used in intensive beef production, but it is unclear if its lower energy supply compared to maize-silage feeding really impairs growth performance. Diets with 100, 300, 500 or 750 g grass silage/kg dry matter replacing maize silage and concentrate were tested with or without dried corn-cob mix (CCM). Performance, carcass and meat quality were studied in 30 Limousin-sired bulls. Feeding grass silage, CCM, and concentrate in a ratio of 500:300:200 allowed to maintain a similar animal performance, carcass and meat quality compared to a conventional maize silage/concentrate diet. Increasing the dietary grass silage proportion to 750 g/kg decreased the shear force of the meat. The proportion of n–3 fatty acids in intramuscular fat increased with dietary grass silage proportion. Consequently, a strategic combination of grass silage with energyrich forages may facilitate grassland-based feeding strategies in intensive beef production with favourable meat fatty acid profiles and a performance comparable to that with maize-silage based diets