Criterion-related validity of the last 7-day, short form of the International Physical Activity Questionnaire in Swedish adults     

Ekelund U  Sepp H  Brage S  Becker W  Jakes R  Hennings M  Wareham NJ 《Public health nutrition》2006,9(2):258-265

OBJECTIVE: To examine the validity of the short, last 7-day, self-administered form of the International Physical Activity Questionnaire (IPAQ). DESIGN: All subjects wore an accelerometer for seven consecutive days and completed the IPAQ questionnaire on the eighth day. Criterion validity was assessed by linear regression analysis and by modified Bland-Altman analysis. Specificity and sensitivity were calculated for classifying respondents according to the physical activity guidelines of the American College of Sports Medicine/Centers for Disease Control and Prevention. SETTING: Workplaces in Uppsala, Sweden. SUBJECTS: One hundred and eighty-five (87 males) participants, aged 20 to 69 years. RESULTS: Total self-reported physical activity (PA) (MET-min day(-1)) was significantly correlated with average intensity of activity (counts min(-1)) from accelerometry (r = 0.34, P < 0.001). Gender, age, education and body mass index did not affect this relationship. Further, subcomponents of self-reported PA (time spent sitting, time in PA, time in moderate and vigorous activity (MVPA)) were significantly correlated with objectively measured PA (P < 0.05). Self-reported time in PA was significantly different from time measured by accelerometry (mean difference: -25.9 min day(-1); 95% limits of agreement: -172 to 120 min day(-1); P < 0.001). IPAQ identified 77% (specificity) of those who met the current PA guidelines of accumulating more than 30 min day(-1) in MVPA as determined by accelerometry, whereas only 45% (sensitivity) of those not meeting the guidelines were classified correctly. CONCLUSIONS: Our results indicate that the short, last 7-days version of the IPAQ has acceptable criterion validity for use in Swedish adults. However, the IPAQ instrument significantly overestimated self-reported time spent in PA. The specificity to correctly classify people achieving current PA guidelines was acceptable, whereas the sensitivity was low.  相似文献   

Evaluation of the prevalence and onset of lung lesions and their impact on growth of lambs     

Daniel JA  Held JE  Brake DG  Wulf DM  Epperson WB 《American journal of veterinary research》2006,67(5):890-894

OBJECTIVE: To determine the prevalence and temporal onset of lung lesions in lambs and the impact of lung lesions on growth of affected lambs. ANIMALS: 259 crossbred wether lambs from a single flock in the upper Midwestern United States. PROCEDURE: An observational study was conducted. Lambs born in the spring and fall were slaughtered at finished weight or at a predetermined time point. Lungs of each lamb were examined and classified as normal, moderate lesions (consolidation > 5% but < or = 50% of any lobe), or severe lesions (consolidation > 50% of any lobe). Data were examined to detect effects of prevalence or severity of lung lesions on growth and carcass traits. RESULTS: 57 of 89 (64%) spring-born lambs had lung lesions characterized by consolidation of lung tissue. A small number of lambs had pulmonary adhesions or active abscesses. In contrast, only 31 of 108 (29%) fall-born lambs had lung lesions. Severe lung lesions were associated with a significant reduction in average daily gain. Severe lung lesions were not detected until the middle of the finishing period and were associated with culture of Mannheimia haemolytica or Pasteurella multocida. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of results indicates that the prevalence of severe lung lesions can be quite high in lambs. Severe lung lesions can lead to greatly decreased growth performance of lambs.  相似文献   

Interspecific hybrids between kenaf (Hibiscus cannabinus) and roselle (H. sabdariffa)     

F. D. Wilson  Margaret Y. Menzel 《Euphytica》1967,16(1):33-44

The successful interspecific cross is reported for the first time between kenaf (Hibiscus cannabinus L.), a diploid species (2n=36) and roselle (Hibiscus sabdariffa L.), a tetraploid species (2n=72). Kenaf, grown for its bast fiber and also under investigation as a source of paper pulp, is fast-growing and well adapted to mechanical harvesting, but susceptible to root-knot nematodes. Roselle, also grown for its bast fiber, is slower growing, not well adapted to mechanical harvesting, but certain varieties are resistant to root-knot nematodes. Five hybrid plants were produced from the pollination of 4,445 flowers of kenaf with pollen from roselle; no hybrid plants were produced from 2,655 pollinations made in the reciprocal direction. One line of roselle was the parent of 3 of the 5 hybrids; one line of kenaf was the parent of 2 of these 3. The F₁ hybrids were triploid, and varied in vigor, growth habit and vegetative morphology, but had similar flowers. Two of the F₁ hybrids showed high pollen fertility, apparently as a result of restitution at first meiotic division leading to unreduced spores. These two hybrids each produced a small amount of seed, which gave rise to an F₂ population of 22 plants. The F₂ plants vary in vigor but are morphologically uniform, have thick leaves with mosaic sectors, and are presumably spontaneous allohexaploids. The theoretical possibilities of increasing the percentage of recovery of the F₁ interspecific hybrids and of developing a synthesized hybrid variety useful for bast fiber and paper pulp are discussed.  相似文献   

Vitamin E: the biological and environmental antioxidant   总被引：2，自引：0，他引：2  

D B Menzel  J N Roehm  S D Lee 《Journal of agricultural and food chemistry》1972,20(3):481-486

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Fate of (14)C-labeled soybean and corn pesticides in tropical soils of Brazil under laboratory conditions     

Laabs V  Amelung W  Fent G  Zech W  Kubiak R 《Journal of agricultural and food chemistry》2002,50(16):4619-4627

The dissipation rate of seven currently used soybean and corn pesticides in two tropical soils (Ustox and Psamments) of Brazil was studied in a laboratory incubation experiment. Dissipation half-lives of pesticides ranged between 2 (monocrotofos) and 90 days (endosulfan-beta). The contrasting clay contents of the studied tropical soils (130 versus 470 g of clay kg(-1) of soil) did not influence the dissipation dynamics of pesticides substantially. Mineralization to CO(2) was high [up to 78% of the applied radioactivity (AR)] for the studied organophosphorus compounds and deltamethrin, which also formed considerable amounts of bound residues (>20% of AR) during the 80 days of incubation. The highest portion of nonextractable residues was found for alachlor and simazine (55-60% of AR). In contrast, the nonpolar trifluralin and endosulfan formed only small amounts of bound residues (mostly <20% of AR) but showed the highest dissipation half-lives (>14 days) in the studied soils, also due to a low mineralization rate. When endosulfan-sulfate, as the main metabolite of endosulfan, was considered, the half-life time of endosulfan compounds (sum of -alpha, -beta, and -sulfate) was enhanced to >160 days in both soils. In comparison with the laboratory experiments, dissipation half-life times of chlorpyrifos, endosulfan-alpha, and trifluralin were shortened by a factor of 10-30 in field trials with the same soils, which was related to the volatilization potential of pesticides from soils.  相似文献   

Nitrogen biomarkers and their fate in soil   总被引：3，自引：0，他引：3  

Wulf Amelung 《植物养料与土壤学杂志》2003,166(6):677-686

More than 90 % of the nitrogen (N) in soils can be organically bound, but the mechanisms and rates by which it is cycled have eluded researchers. The objective of this research was to contribute to a better understanding of the origin and transformation of soil organic N (SON) by using amino sugars and the enantiomers of amino acids as markers for microbial residues and/or aging processes. Studied samples presented here comprised (1) soil transects across different climates, (2) arable soils with different duration of cropping, and (3) radiocarbon‐dated soil profiles. The results suggested that increased microbial alteration of SON temporarily results in a sequestration of N in microbial residues, which are mineralized at later stages of SON decomposition. Microorganisms increasingly sequestered N within intact cell wall residues as frost periods shortened. At a mean annual temperature above 12–15 °C, these residues were mineralized, probably due to limitations in additional substrates. Breaking the grassland for cropping caused rapid SON losses. Microbial residues were decomposed in preference to total N, this effect being enhanced at higher temperatures. Hence, climate and cultivation interactively affected SON dynamics. Nevertheless, not all SON was available to soil microorganisms. In soil profiles, L‐aspartic acid and L‐lysine slowly converted into their D‐form, for lysine even at a similar rate in soils of different microbial activity. Formation of D‐aspartate with time was, therefore, induced by microorganisms while that of D‐lysine was not. The racemization of the two amino acids indicates that SON not available to microorganisms ages biotically and abiotically. In native soils, the latter is conserved for centuries, despite N deficiency frequently occurring in living terrestrial environments. Climate was not found to affect the fate of old protein constituents in surface soil. When native grassland was broken for cropping, however, old SON constituents had become available to microorganisms and were degraded.  相似文献   

Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAHs) in a Rural Community Leewards of a Waste Incineration Plant     

Wolfgang Wilcke  Wulf Amelung  Wolfgang Zech 《植物养料与土壤学杂志》1997,160(3):369-378

In a rural community (Stephanskirchen, Southern Germany) near a waste incineration plant 7 soils, sewage sludge, waste incineration residues, the gutter sediment of a family home, and mosses were sampled to determine the total concentrations of Cd, Pb, Zn and 20 PAHs. Representative samples were used to measure NH₄NO₃- and EDTA-extractable Cd, Pb, and Zn as well as 20 PAHs in particle size separates (clay, silt, fine and coarse sand). Sites near the main road, hill top, and forested sites contain up to 1.24 mg Cd, 888 mg Pb, and 279 mg Zn per kg. The heavy metal concentrations of the sewage sludge, the gutter sediment, and especially the waste incineration residues are extremely high (up to 57 mg Cd, 3300 mg Pb, and 5700 mg Zn per kg). The extractability of Pb and Zn with NH₄NO₃ is low (< 5%), that with EDTA is high (up to 71.2% of total Cd, 82.5% of total Pb, and 47.2% of total Zn). The sum concentrations of PAHs range between 0.4 and 470 mg kg^?1. The silt has the highest PAH concentrations of the particle size separates. High saturation of organic matter with PAHs in the sand indicates high recent PAH deposition. Selected ratios of single PAHs reveal diesel and gasoline exhausts as main sources for PAH. Principal component and cluster analysis show that the pollutant pattern depends on the C_org concentration and on the time passed since deposition. There is no significant influence of the waste incineration emissions on the heavy metal and PAH concentrations.  相似文献   

Relating bat species presence to simple habitat measures in a central Appalachian forest     

W. Mark Ford  Michael A. Menzel  Jennifer M. Menzel 《Biological conservation》2005,126(4):528-539

We actively sampled the bat community at 63 sites using detection and non-detection metrics on the Fernow Experimental Forest (FEF) in the central Appalachians of West Virginia using Anabat acoustical equipment May-June 2001-2003 to relate species presence to simple habitat measures such as proximity to riparian areas, forest canopy cover, forest canopy gap width, and forest canopy height. We acoustically detected eight species on the FEF, including the endangered Myotis sodalis. The presence of Lasiurus cinereus, M. lucifugus, M. sodalis, and Pipistrellus subflavus was associated more with riparian areas than upland areas. Both univariate comparisons and multiple logistic regression modeling showed that the probability that clutter-adapted foraging species such as M. septentrionalis and M. sodalis would be detected was greater as forest canopy cover increased or forest canopy gap size decreased, whereas the opposite was true for open-adapted foraging species such as Eptesicus fuscus and L. cinereus. The overall proportion of unidentifiable bat echolocation sequences to those identified to species was related to upland sites with increasing forest canopy cover indicating some sampling bias between cluttered and uncluttered habitats. However, given sufficient sample points, bat community surveys using acoustical detection show the ability to quickly develop generalized habitat associations for rugged areas such as the central Appalachians where traditional mist-net survey efforts often are logistically difficult and are lacking in scope. Moreover, these acoustical surveys also could lend themselves to species-specific predictive mapping of foraging habitat as well as allowing researchers to formulate testable hypotheses about detailed bat habitat relationships to be definitively tested with radio-telemetry techniques.  相似文献   

THE SOURCE OF SOLAR ENERGY     

Menzel DH 《Science (New York, N.Y.)》1927,65(1688):431-438

While I have wandered from the main subject of the sun, to consider the source of stellar energy, the two topics are so intimately related that their solutions are identical. I consider that I have demonstrated the reasonableness of Jeans's theory by the manner in which it seems to fit the observed facts. There is, as I can see, no important objection to the hypothesis. It is too much to hope that the foregoing analysis is rigidly complete, but I confidently believe that the main points are established and that further modification will consist in the clearing up of details. The application of astrophysics and atomic theory to a new field appears to have met with considerable success. In spite of this success, however, caution is necessary. The present position of the theory advocated in this paper is somewhat analogous to the place once held by the theory of Helmholtz-i.e., it is the only one sufficiently elastic to stretch over the region of known facts. Our knowledge is yet limited and, with our vision thus impaired, we can not predict the future. Some unforeseen event may upset our present hypothesis as completely as that of Helmholtz; we have built as securely as possible upon observation, and it remains for the future to test the accuracy of this or any other theory so established. In an attempt to discover a reasonable explanation of the origin and duration of the solar radiation, all possible sources of energy are examined. The following hypotheses are reviewed and discarded, the arguments against their validity being too well known to necessitate a review at this place; (1) Original Heat; (2) Chemical; (3) Gravitational, (a) Meteoric, (b) Contraction; (4) Radioactive.  相似文献   

PROTEIN FRACTIONS OF THE H 37 (HUMAN) STRAIN OF TUBERCLE BACILLUS     

Heidelberger M  Menzel AE 《Science (New York, N.Y.)》1933,77(1984):24-25

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