Low fitness partially explains resting metabolic rate differences between African American and white women

Background High levels of obesity among African American women have been hypothesized to be partially resultant from a lower resting metabolic rate compared with white women. The aim of the current study was to determine if differences in cardiorespiratory fitness and moderate-to-vigorous physical activity are associated with differences in resting metabolic rate among free-living young adult African American women and white women. Methods Participants were 179 women (white women n = 141, African American women n = 38, mean age = 27.7 years). Resting metabolic rate was measured using indirect calorimetry, body composition using dual energy x-ray absorptiometry, cardiorespiratory fitness via maximal treadmill test, and moderate-to-vigorous physical activity using an activity monitor. Results African American women had higher body mass index, fat mass, and fat-free mass compared with white women but lower levels of cardiorespiratory fitness. No differences were observed between African American and white women in resting metabolic rate when expressed as kcal/day (1390.8 ± 197.5 vs 1375.7 ± 173.6 kcal/day, P =.64), but African American women had a lower resting metabolic rate when expressed relative to body weight (2.56 ± 0.30 vs 2.95 ± 0.33 mL/kg/min,

Safety of Autologous Umbilical Cord Blood Therapy for Acquired Sensorineural Hearing Loss in Children

This article presents the results of a phase 1 clinical trial to evaluate the intravenous administration of human umbilical cord blood (hUCB) mononuclear fraction in infants and children with acquired sensorineural hearing loss (SNHL)

Aircraft engine particulate matter emissions from sustainable aviation fuels: Results from ground-based measurements during the NASA/DLR campaign ECLIF2/ND-MAX

The use of alternative jet fuels by commercial aviation has increased substantially in recent years. Beside the reduction of carbon dioxide emission, the use of sustainable aviation fuels (SAF) may have a positive impact on the reduction of particulate emissions. This study summarizes the results from a ground-based measurement activity conducted in January 2018 as part of the ECLIF2 ND-MAX campaign in Ramstein, Germany. Two fossil reference kerosenes and three different blends with the renewable fuel component HEFA-SPK (Hydroprocessed Esters and Fatty Acids Synthetic Paraffinic Kerosene) were burned in an A320 with V2527-A5 engines to investigate the effect of fuel naphthalene aromatic content and the corresponding fuel hydrogen content on nonvolatile particle number and mass emissions

Aircraft-Engine Particulate Matter Emissions From Conventional and Sustainable Aviation Fuel Combustion: Comparison of Measurement Techniques for Mass, Number, and Size

13-C-AJFF-MST-010This is an open access article under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) license https://creativecommons.org/licenses/by/4.0/. Please cite this article as: Corbin, J. C., Schripp, T., Anderson, B. E., Smallwood, G. J., LeClercq, P., Crosbie, E. C., Achterberg, S., Whitefield, P. D., Miake-Lye, R. C., Yu, Z., Freedman, A., Trueblood, M., Satterfield, D., Liu, W., O fwald, P., Robinson, C., Shook, M. A., Moore, R. H., and Lobo, P.: Aircraft-engine particulate matter emissions from conventional and sustainable aviation fuel combustion: comparison of measurement techniques for mass, number, and size, Atmos. Meas. Tech., 15, 3223\u20133242, https://doi.org/10.5194/amt-15-3223-2022, 2022.Sustainable aviation fuels (SAFs) have different compositions compared to conventional petroleum jet fuels, particularly in terms of fuel sulfur and hydrocarbon content. These differences may change the amount and physicochemical properties of volatile and non-volatile particulate matter (nvPM) emitted by aircraft engines. In this study, we evaluate whether comparable nvPM measurement techniques respond similarly to nvPM produced by three blends of SAFs compared to three conventional fuels. Multiple SAF blends and conventional (Jet A-1) jet fuels were combusted in a V2527-A5 engine, while an additional conventional fuel (JP-8) was combusted in a CFM56-2C1 engine

CINTRAFOR Working Paper 78

Approximately 85 percent of all single family homes in the US include a deck or deck-like structure (e.g., patio, porch, or balcony), which is equivalent to roughly 30 million decks. Sixty percent of all new homes are constructed with a deck, while nearly 2.75 million decks are replaced on an annual basis (the average deck has a life expectancy of about eleven years). Furthermore, slightly over 4 percent of all households add a deck to their home on an annual basis, resulting in another 3 million new decks. Collectively, over 6.5 million new decks have been constructed throughout the US on an annual basis since 1995, which represents approximately $3 billion spent annually in deck materials. During the decade of the 1990s, the deck market grew at an average annual rate of 8.1 percent. Assuming a constant rate of growth of 8.1 percent, the deck market in 2010 could be as large as$6.5 billion. Despite the enormous size and healthy growth of the residential deck market in the US, very little research has been conducted evaluating consumer perceptions of the various deck materials available to them in the market. The objective of this study was to review secondary information regarding the residential deck material market in the US. Additionally, a survey of residential homebuilders in the US was conducted to characterize the industry’s use of various deck materials, as well as to assess the industry’s perceptions of these deck materials

CINTRAFOR Working Paper 73

The US residential construction industry, traditionally the largest market for softwood lumber, has undergone a period of uncharacteristically rapid change over the past decade. The effects of timber harvest restrictions in federal and state forests on softwood lumber price, price volatility, and product quality, combined with technological advances by producers of substitute materials, have contributed to increased use of material substitutes in residential construction. The objective of this research was to assess the extent of material substitution in residential construction and provide insight into the factors driving these changes. The results offer convincing evidence that softwood lumber has continued to lose market share in the residential construction industry and that builders remain concerned about its quality and price. The study also shows a shift on the part of builders towards a more favorable impression of the environmental impacts of substitute products, including steel and concrete, relative to softwood lumber. This study is based on a random sample of 2,400 residential construction firms segmented by geographic region and firm size. The survey was also mailed to the 100 largest home builders, as reported in Builder magazine. The overall response rate was 12.8% (12.1% of the random sample and 37.1% of the 100 largest firms). The results show that residential builders have steadily increased their use of substitute structural materials since 1995. Respondents reported increased use of all of substitute materials included in the survey. Almost all respondents reported using at least one substitute material (compared to 91% in 1995) and over 80% of the respondents reported using glulam beams, wood I-joists, and laminated veneer lumber (LVL). While use of steel, reinforced concrete and plastic-fiber lumber increased, engineered wood products emerged as the clear winners. On a regional basis, builders in the western US reported higher usage of all substitute products. In addition, the survey data suggest that large firms were more likely than small firms to try new substitute products, particularly finger jointed lumber, structural insulated panels, laminated veneer lumber, as well as newer engineered wood products such as parallel strand lumber and laminated strand lumber. The survey data were analyzed to assess the extent to which various structural products were used in walls, floors, and roofs, the three end-use applications that consume the greatest volume of structural lumber. The most commonly used products were softwood lumber, steel lumber, finger-jointed lumber, wood trusses, LVL, and wood I-joists. While softwood lumber still dominated wall framing in 1998, with an 83% market share, it has lost market share (down from 93% in 1995), particularly among large firms. Softwood lumber’s share of the floor framing market declined from 59% in 1995 to 42% in 1998. While it is still the most widely used product, with a 42% market share, the market share of wood I-joists has increased from 23% in 1995 to 39% in 1998. Softwood lumber used to frame roof rafters is no longer the dominant material used in residential roof systems. Survey data show that wood trusses increased slightly from 46% to 48%, while softwood lumber declined from 51% to 40%. To assess builders’ satisfaction with softwood lumber, respondents were asked to rate the level of the importance, and their corresponding level of satisfaction, with 13 softwood lumber attributes. The importance ratings obtained in 1998 were virtually identical to those reported in 1995. Softwood lumber straightness, strength, availability, and lack of defects were rated as the most important attributes. The survey data suggest that price is much more important to large firms than small firms. Builders reported that, while they were more satisfied with the price and price stability of softwood lumber in 1998 relative to 1995, they remained unhappy with softwood lumber quality, particularly with respect to lumber straightness and overall occurrence of defects. A gap analysis highlighted the difference between the mean importance ratings (where 7 indicates “extremely important” and 1 indicates “not important at all”) and the mean satisfaction ratings for each product attribute (where 7 indicates “extremely satisfied” and 1 indicates “extremely dissatisfied”). Survey findings indicate that while builders are less concerned with price issues than in 1995, they remain very concerned about the perceived decline in softwood lumber quality. The data provide clear evidence that residential home builders are least satisfied with product attributes they rate most important, suggesting that builders are dissatisfied with the value (defined as the ratio of price/quality) of softwood lumber. To provide a more concise interpretation of the importance and satisfaction of the different softwood lumber attributes, a factor analysis was performed to group together those softwood lumber attributes that are highly correlated to each other. The results of the factor analysis are almost identical with the results obtained from the 1995 survey and suggest that the 13 product attributes used to describe softwood lumber can be summarized into three factors: quality attributes, economic attributes, and technical attributes. Finally, the survey assessed builders’ perceptions of the environmental impact associated with using substitute products relative to softwood lumber. Although environmental marketing is not prevalent in the US forest products industry, most industry observers believe that it will become more important. While reduced environmental impact had the lowest importance rating of the 13 softwood lumber attributes, survey findings revealed that more builders in 1998 had a favorable perception of the environmental impact of substitute products, including steel and concrete, over softwood lumber than in 1995. This survey clearly indicates that softwood lumber has continued to be displaced by substitute materials in segments of the residential construction industry that it has traditionally dominated: walls, floors, and roofs. To a large degree, this loss of market share can be attributed to a perception among residential builders that the value of softwood lumber has declined: a direct result of rising prices and a perceived drop in lumber quality. Much of the loss in market share experienced by softwood lumber can be attributed to the increased use of engineered wood products. Many would argue that this is a normal process of product evolution within the forest products industry, attributed to technological advances in manufacturing processes driven by the changing forest resource. However, this study identified two trends that should concern managers in the forest products industry. First, the use of nonwood substitute building materials has increased significantly since 1995. Second, there is a growing perception among home builders that using non-wood building materials (including steel and reinforced concrete) is better for the environment than using softwood lumber. This trend away from wood products is likely to continue unless there is an effective response to the challenge posed by substitute materials

Extremes of weight gain and weight loss with detailed assessments of energy balance: illustrative case studies and clinical recommendations

Extreme weight changes, or changes in weight greater than 10 kg within a 2-year period, can be caused by numerous factors that are much different than typical weight fluctuations. This paper uses two interesting cases of extreme weight change (a female who experienced extreme weight gain and a male who experienced extreme weight loss) from participants in the Energy Balance Study to illustrate the physiological and psychosocial variables associated with the weight change over a 15-month period, including rigorous assessments of energy intake, physical activity (PA) and energy expenditure, and body composition. In addition, we provide a brief review of the literature regarding the relationship between energy balance (EB) and weight change, as well as insight into proper weight management strategies. The case studies presented here are then placed in the context of the literature regarding EB and weight change. This report further supports previous research on the importance of regular doses of PA for weight maintenance, and that even higher volumes of PA are necessary for weight loss. Practitioners should emphasize the importance of PA to their patients and take steps to monitor their patients’ involvement in PA