Economic growth, carrying capacity, and the environment   总被引：11，自引：0，他引：11  

Arrow K  Bolin B  Costanza R  Dasgupta P  Folke C  Holling CS  Jansson BO  Levin S  Mäler KG  Perrings C  Pimentel D 《Science (New York, N.Y.)》1995,268(5210):520-521

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Krypton Fluoride: Preparation by the Matrix Isolation Technique     

Turner JJ  Pimentel GC 《Science (New York, N.Y.)》1963,140(3570):974-975

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Soil erosion: a carbon sink or source?     

Lal R  Pimentel D 《Science (New York, N.Y.)》2008,319(5866):1040-2; author reply 1040-2

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Biomass energy from crop and forest residues     

Pimentel D  Moran MA  Fast S  Weber G  Bukantis R  Balliett L  Boveng P  Cleveland C  Hindman S  Young M 《Science (New York, N.Y.)》1981,212(4499):1110-1115

Residues remaining after the harvest of crop and forestry products are being proposed as a substantial energy source for the nation. An estimated 22 percent of the residues might be utilized, providing a renewable source of high-grade energy with the potential of supplying 1 percent of the current U.S. gasoline consumption as ethanol or 4 percent of the total electrical energy used. These net energy benefits are limited by high energy costs to collect, transport, and process the residues. Environmental threats include soil erosion, water runoff, and nutrient loss.  相似文献   

Influence of different drying and aging conditions on saffron constituents     

Carmona M  Zalacain A  Pardo JE  López E  Alvarruiz A  Alonso GL 《Journal of agricultural and food chemistry》2005,53(10):3974-3979

A dehydration postharvesting treatment is necessary to convert Crocus sativus L. stigmas into saffron spice. Three different dehydration treatments were evaluated: dehydration at room temperature; dehydration with hot air at different temperatures (70, 90, and 110 degrees C); and dehydration following traditional processing in Castille-La Mancha (Spain) with three different heating sources (vineshoot charcoal, gas cooker, and electric coil). The time (between 28 and 55 min) and mean temperature (between 54 and 83 degrees C) conditions for traditional dehydration were established for the first time. The highest coloring strength was obtained when saffron was submitted to higher temperatures and lower times. These findings may be supported by the fact that samples dehydrated at high temperature were more porous than those dehydrated at room temperature, as was observed by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The higher the temperature during the process, the higher the proportion of trans-crocetin di-(beta-D-gentibiosyl) ester, although trans-crocetin (beta-D-glucosyl)-(beta-D-gentibiosyl) and trans-crocetin di-(beta-D-glucosyl) ester decrease while cis-crocins did not change significantly. A thermal aging process reveals that the trans-crocetin di-(beta-D-gentibiosyl) ester increases when saffron is resubmitted to a heating treatment before it is decomposed by the extreme conditions. The picrocrocin extinction during the aging process does not imply a consistent generation of safranal.  相似文献   

Intake,digestibility, ingestive behavior,and nitrogen balance of goats fed with diets containing residue from tamarind fruit     

Galvão  J. M.  Silva  T. M.  Silva  W. P.  Pimentel  P. R. S.  Barbosa  A. M.  Nascimento  T. V. C  Lima  A. G. V. O.  Bezerra  L. R.  Oliveira  R. L. 《Tropical animal health and production》2020,52(1):257-264

This study is aimed at determining the maximum inclusion level of tamarind (Tamarindus indica) residues in the diet of goats on intake, digestibility, ingestive behavior, and nitrogen (N) balance. Twenty-four crossbred (Boer × undefined breed) castrated goat kids (5 months old and with an initial weight of 23.9?±?0.3 kg) were assigned in a completely randomized design (4 treatments and 6 replicates). Diets consisted of Tifton 85 (Cynodon sp.) hay as the roughage (400 g/kg) source and concentrate (600 g/kg); the levels of tamarind residue inclusion were 0.0, 7.0, 14.0, and 21.0% on a dry matter (DM) basis. The experimental period lasted 23 days (15 of adaptation and 8 of sampling). Inclusion of tamarind residue in the goat kid diets did not affect (P?>?0.05) the intake and digestibility of DM, crude protein, neutral detergent fiber (NDF), and total digestible nutrient; intake of N, urinary N, and retained N (g/day); time spent ruminating; numbers of times/day feeding, ruminating, or idling; eating efficiency of DM and NDF; number of boluses/day; and amount (g) of DM/bolus. However, there were a linear reduction in ether extract digestibility (P?=?0.011) and a linear decreasing trend in non-fibrous carbohydrate digestibility (P?=?0.083). The addition of tamarind residue had a positive linear effect (P?=?0.041) on the time spent feeding and promoted a decreasing linear trend for the time spent idling (P?=?0.063). It is recommended to include the residue from tamarind fruit at a level of 21% in diets for goat kids, as it does not affect nutrient intake and digestibility and the N balance.

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Effects of estrone infusion on secretion of F series prostaglandins and on function of the corpus luteum during late gestation in cattle     

C A Pimentel  R Vijayakumar  P G Weston  S M Pimentel  W C Wagner  J E Hixon 《American journal of veterinary research》1986,47(9):1972-1977

Catheters were surgically implanted in the carotid artery, jugular vein, and middle uterine vein of 8 cows at 245 days of gestation. Four cows were given 4 mg of estrone/hour via continuous jugular infusion from 0800 hours on day 246 of gestation through 0800 hours on day 250 of gestation; the remaining 4 cows (controls) were given the vehicle for estrone at 10 ml/hour for the same period. Blood samples were collected from the carotid artery every 3 hours during the infusion. Samples were collected hourly from the middle uterine vein from 0 through 8, 54 through 66, and 112 through 120 hours of the infusion periods. After completion of the infusion, corpora lutea were enucleated and blood samples were collected from the carotid artery and uterine vein at hourly intervals for an additional 8 hours. Dispersed cell preparations of the corpora lutea were incubated with and without luteinizing hormone (LH) or dibutyryl cyclic adenosine monophosphate (dbcAMP). Circulating concentrations of unconjugated and conjugated estrone and estradiol-17 beta were higher (P less than 0.05) in the group infused with estrone than in the vehicle-infused group. Mean and base-line concentrations of F series prostaglandins (PGF) for each blood collection period tended to increase (P less than 0.10) during infusion with estrone, but not during infusion with vehicle. After luteectomy, mean and base-line concentrations of PGF also tended (P less than 0.10) to be greater in the estrone-infused cows than in the control cows, but a surge in PGF concentrations due to removal of the ovarian source of progesterone did not develop.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Malnutrition,disease, and the developing world     

Pimentel D  Morse J 《Science (New York, N.Y.)》2003,300(5617):251

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Infrared Absorptions near Three Microns Recorded over the Polar Cap of Mars     

Herr KC  Pimentel GC 《Science (New York, N.Y.)》1969,166(3904):496-499

During the Mariner 7 flyby of Mars, the infrared spectrometer recorded distinct, sharp absorption. near 3020 and 3300 reciprocal centimeters between 61 degrees S and 80 degrees S. at the edge of the southern polar cap, with maximum optical density near 68 degrees S and 341 degrees E. These hands, which match in frequency the v(3) bands of methane and ammonia, can be associated with previously unreported spectral features of solid carbon dioxide exceeding 1 millimeter in thickness. Possible reasons for the geographic localization are discussed.  相似文献   

Interplay between heritability,genetic correlation and economic weighting in a selection index with and without genomic information     

A.M. Haberland  E.C.G. Pimentel  F. Ytournel  M. Erbe  H. Simianer 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2013,130(6):456-467

The availability of genomic information demands proper evaluation on how the kind (phenotypic versus genomic) and the amount of information influences the interplay of heritability (h²), genetic correlation () and economic weighting of traits with regard to the standard deviation of the index (σ_I). As σ_I is directly proportional to response to selection, it was the chosen parameter for comparing the indices. Three selection indices incorporating conventional and genomic information for a two trait (i and j) breeding goal were compared. Information sources were chosen corresponding to pig breeding applications. Index I incorporating an own performance in trait j served as reference scenario. In index II, additional information in both traits was contributed by a varying number of full‐sibs (2, 7, 50). In index III, the conventional own performance in trait j was combined with genomic information for both traits. The number of animals in the reference population (N_P = 1000, 5000, 10 000) and thus the accuracy of GBVs were varied. With more information included in the index, σ_I became more independent of , and relative economic weighting. This applied for index II (more full‐sibs) and for index III (more accurate GBVs). Standard deviations of index II with seven full‐sibs and index III with N_P = 1000 were similar when both traits had the same heritability. If the heritability of trait j was reduced ( = 0.1), σ_I of index III with N_P = 1000 was clearly higher than for index II with seven full‐sibs. When enhancing the relative economic weight of trait j, the decrease in σ_I of the conventional full‐sib index was much stronger than for index III. Our results imply that N_P = 1000 can be considered a minimum size for a reference population in pig breeding. These conclusions also hold for comparing the accuracies of the indices.  相似文献