The behavior of hybrid bolted connections

This report presents the results of an extensive theoretical analysis of hybrid steel butt joints fastened with either A325 or A490 bolts. The primary purpose of the theoretical studies was to ascertain the effect of various variables on the ultimate joint strength

Vesicular-Arbuscular Mycorrhiza and Soil Fertility Influence Mineral Concentrations in Seedlings of Eight Hardwood Species

Eight hardwood species were grown under two sets of fertilizer and vesicular–arbuscular mycorrhizae (VAM) treatments. In the first study three treatments of 140, 560, and 1120 kg/ha of 10– 10– 10 (% N, P2O5, and K2O, respectively) fertilizer were added to fumigated soil with or without a mixture of Glomusmosseae Nicol. and Gerd. and Glomusetunicatus Becker and Gerd. (GM). In the second study, seedlings were grown with VAM treatments of (i) the same Glomus(GM) mixture as in study 1, (ii) Glomusfasiculatus (Thaxter) Gerd. and Trappe (GF), or (iii) mixed cultures of several Glomus and Gigaspora species (GG). A fertilizer treatment of 280 kg/ha of 10– 10– 10 was added to all seedlings. All treatments, in both studies, also received 10 equal applications of NH4NO3, totaling 1680 kg/ha, during the growing season. No single nutrient was consistently higher in nonmycorrhizal or VAM seedlings in either study and no symbiont produced consistently high concentrations of all nutrients in all species. Uninoculated seedlings frequently had higher N, K, Ca, and Mg concentrations than VAM seedlings. Inoculated seedlings generally had higher total P concentrations than uninoculated seedlings. For uninoculated seedlings of five of the species, P concentrations increased with higher fertility levels. Seedlings inoculated with GM and GG had higher P concentrations than those inoculated with GF. In numerous instances, uninoculated seedlings had higher mineral concentrations than VAM seedlings even though the uninoculated seedlings were always the smallest. This suggests that VAM provide stimulation other than or in addition to the enhanced nutrient uptak

Significance of Sewage Sludge Amendments to Borrow Pit Reclamation With Sweetgum and Fescue

Sweetgum (Liquidambar styraciflua L.) and fescue (Festuca arundinocea Schreb.) were planted after subsolling and sludge applications to depths of 0, 0. 64, 1.27, and 2.54 em to reclaim a borrow pit In the Lower Piedmont of South Carolina. Sludge treatments in combination with subsoiling significantly improved establishment of fescue and growth of sweetgum, but all combinations of fescue with sludge significantly reduced first-year survival of sweetgum. Because survival was stabilized after the first growing season, allelopathy of fescue to sweetgum had little effect in this study . Fifth-year total height growth (0. 74 m) of sweetgum on the nonamended plots was rated not acceptable, but on plots amended at even the lowest rate of sludge, height growth (2.75 m) was acceptable. Total heights (ca 3.6 m) after 5 years on plots amended at the two highest sludge rates were equal to or greater than 5-year heights reported for sweetgum on reforestation sites . The increase in total nitrogen available on the site after 5 years exceeded the amount initially present in the sludge, which suggests either a significant atmospheric contribution or that organic matter enhanced nitrogen fixation

Identification and characterization of the biochemical and physiological functions of Acyl-CoA dehydrogenase 10

The acyl-CoA dehydrogenase, ACAD, genes encode enzymes that are essential to cellular metabolism as evidenced by the identification in the past 20 years of genetic defects associated with nine members of this gene family. In total, these defects constitute the most common inborn errors of metabolism identified through newborn screening and so are concerns to public health. Recently, two new ACADs, ACAD10 and 11, of unknown function have been identified. This discovery raises the specter of additional unrecognized disorders since prior studies on these two ACADs suggested a novel role in metabolism. Recently, ACAD10 has been linked to type 2 diabetes in Pima Indians, which draws additional attention to its role in metabolism and public health importance. Both ACAD10 and ACAD11 are highly conserved but with unique additional large protein domains compared to other ACADs, likely encoded from multiple coding domains. ACAD10 antigen in mice is present in lung, muscle, kidney, and pancreas, and localized to mitochondria, while a weak signal is also observed in peroxisomes of mouse lung. Human tissues including lung, kidney, liver, muscle, and pancreas reveal antigen present in mitochondria, and a weak antigen signal in peroxisomes in kidney and pancreas. To investigate the role of ACAD10 in metabolism further, I have generated an Acad10 deficient mouse and have characterized it through pathological, biochemical, and molecular studies. Deficient animals are viable and fertile, but become obese. Pathological studies reveal inflammatory liver disease and secondary splenic extramedullary hematopoiesis. Skeletal muscle findings were abnormal , consistent with deficient mice have elevated creatine kinase when fasting, indicative of rhabdomyolysis. Metabolomics analysis identified elevated levels of a variety of acylcarnitine species in deficient mouse samples consistent with mild, global energy dysfunction. Most dramatically, animals develop a syndrome consistent with insulin insensitivity characteristic of type 2 diabetes mellitus in humans. A better understanding of the biochemical pathways and physiological role of ACAD10, as well as the pathophysiology of disorders occurring among this new ACAD family member will allow identification and treatment of patients with ACAD10 deficiency, as well as its role in obesity and type 2 diabetes

Soil Phosphorus and pH Influence the Growth of Mycorrhizal Sweetgum

The response of sweetgum (Liquidambar styraciflua L.) seedlings grown either without or inoculated with the vesicular-arbuscular mycorrhizal (VAM) fungus Gigaspora margarita‘Becker’ and ‘Hall’ to 25, 50, and 100 ppm soil phosphorus (P) and adjusted soil pHs of 4.5, 5.5, 6.5, and 7.8 was observed during the first growing season. The best seedling growth for both VAM and noninoculated seedlings occurred at soil pH 4.5 and 100 ppm of soil P where mean heights and top dry weights averaged \u3e 28 cm and 8 g, respectively. As soil pH increased, seedling growth decreased significantly and at pH 7.8 the seedlings averaged \u3c 4 cm in height regardless of the soil P level or mycorrhizal condition. Seedling growth at all pH levels, except pH 7.8, decreased with decreasing soil P. Inoculated seedlings were significantly larger than noninoculated seedlings at 25 ppm soil P and pHs 4.5 and 5.5. Soil P, soil pH, and mycorrhizal condition significantly influenced nutrient levels in plant parts. Soil nutrient levels varied significantly with soil pH

Effects of Fertilization and Vesicular-Arbuscular Mycorrhizal Inoculation on Growth of Hardwood Seedlings

Eight hardwood species were grown in fumigated soil without vesicular-arbuscular mycorrhizae (VAM) or in soil infested with a mixture of Glomus mosseae and Glomus etunicatus. Three fertilizer treatments of 140, 560, and 1,120 kg/ha of 10-10-10 fertilizer were established in combination with the two mycorrhizal treatments. Ten equal applications of NH4NO3, totaling 1,680 kg/ha, were added to all the treatment plots during the growing season. For six of the eight species, the VAM seedlings showed greater height and diameter growth and dry weight production than nonmycorrhizal seedlings. Sugar maple (Acer saccharum Marsh.) and walnut (Juglans nigra L.) displayed no height growth differences. Only boxelder (Acer negundo L.), of the inoculated seedlings, consistently responded to increases in fertilizer level. Nonmycorrhizal seedlings generally showed increased growth with increased fertilizer applications. The growth of the nonmycorrhizal seedlings at the higher fertilizer levels was not sufficient to produce plantable seedlings for artificial regeneration. A difference in host preference for the Glomus spp. symbionts is suggested by the large difference in infection between species. Infection values varied from a high of about 80% for sycamore (Platanus occidentalis L.), green ash (Fraxinus pennsylvanicaMarsh.), and boxelder to a low of 40% for sugar maple and sweetgum. The growth data suggest that high quality seedling stock of most of these hardwood tree species can be obtained in nurseries as long as cultural practices in the nursery encourage VAM development