Soft-tissue vessels and cellular preservation in Tyrannosaurus rex     

Schweitzer MH  Wittmeyer JL  Horner JR  Toporski JK 《Science (New York, N.Y.)》2005,307(5717):1952-1955

Soft tissues are preserved within hindlimb elements of Tyrannosaurus rex (Museum of the Rockies specimen 1125). Removal of the mineral phase reveals transparent, flexible, hollow blood vessels containing small round microstructures that can be expressed from the vessels into solution. Some regions of the demineralized bone matrix are highly fibrous, and the matrix possesses elasticity and resilience. Three populations of microstructures have cell-like morphology. Thus, some dinosaurian soft tissues may retain some of their original flexibility, elasticity, and resilience.  相似文献   

Genetics. Poultry genetic resources--operation rescue needed     

Fulton JE  Delany ME 《Science (New York, N.Y.)》2003,300(5626):1667-1668

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Organic aerosol growth mechanisms and their climate-forcing implications     

Maria SF  Russell LM  Gilles MK  Myneni SC 《Science (New York, N.Y.)》2004,306(5703):1921-1924

Surface- and volume-limited chemical reactions on and in atmospheric aerosol particles cause growth while changing organic composition by 13 to 24% per day. Many of these particles contain carbonaceous components from mineral dust and combustion emissions in Africa, Asia, and North America and reveal reaction rates that are three times slower than those typically used in climate models. These slower rates for converting from volatile or hydrophobic to condensed and hygroscopic organic compounds increase carbonaceous particle burdens in climate models by 70%, producing organic aerosol climate forcings of as much as -0.8 watt per square meter cooling and +0.3 watt per square meter warming.  相似文献   

Kilimanjaro ice core records: evidence of holocene climate change in tropical Africa   总被引：1，自引：0，他引：1  

Thompson LG  Mosley-Thompson E  Davis ME  Henderson KA  Brecher HH  Zagorodnov VS  Mashiotta TA  Lin PN  Mikhalenko VN  Hardy DR  Beer J 《Science (New York, N.Y.)》2002,298(5593):589-593

Six ice cores from Kilimanjaro provide an approximately 11.7-thousand-year record of Holocene climate and environmental variability for eastern equatorial Africa, including three periods of abrupt climate change: approximately 8.3, approximately 5.2, and approximately 4 thousand years ago (ka). The latter is coincident with the "First Dark Age," the period of the greatest historically recorded drought in tropical Africa. Variable deposition of F- and Na+ during the African Humid Period suggests rapidly fluctuating lake levels between approximately 11.7 and 4 ka. Over the 20th century, the areal extent of Kilimanjaro's ice fields has decreased approximately 80%, and if current climatological conditions persist, the remaining ice fields are likely to disappear between 2015 and 2020.  相似文献   

Interpreting sequences from mastodon and T. rex     

Asara JM  Garavelli JS  Slatter DA  Schweitzer MH  Freimark LM  Phillips M  Cantley LC 《Science (New York, N.Y.)》2007,317(5843):1324-1325

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Vitamin D and sterol composition of 10 types of mushrooms from retail suppliers in the United States     

Phillips KM  Ruggio DM  Horst RL  Minor B  Simon RR  Feeney MJ  Byrdwell WC  Haytowitz DB 《Journal of agricultural and food chemistry》2011,59(14):7841-7853

Vitamin D(2) (ergocalciferol) and sterols were analyzed in mushrooms sampled nationwide in the United States to update the USDA Nutrient Database for Standard Reference. Vitamin D(2) was assayed using HPLC with [(3)H]-vitamin D(3) internal standard and sterols by GC-FID mass spectrometric (MS) confirmation. Vitamin D(2) was low (0.1-0.3 μg/100 g) in Agaricus bisporus (white button, crimini, portabella) and enoki, moderate in shiitake and oyster (0.4-0.7 μg/100 g), and high in morel, chanterelle, maitake (5.2-28.1 μg/100 g) and UV-treated portabella (3.4-20.9 μg/100 g), with significant variability among composites for some types. Ergosterol (mg/100 g) was highest in maitake and shiitake (79.2, 84.9) and lowest in morel and enoki (26.3, 35.5); the range was <10 mg/100 g among white button composites but 12-50 mg/100 g among samples of other types. All mushrooms contained ergosta-5,7-dienol (22,23-dihydroergosterol) (3.53-18.0 mg/100 g) and (except morel) ergosta-7-enol. Only morel contained brassicasterol (28.6 mg/100 g) and campesterol (1.23-4.54 mg/100 g) and no ergosta-7,22-dienol. MS was critical in distinguishing campesterol from ergosta-7,22-dienol.  相似文献   

Suspected epidural morphine analgesia induced chronic urinary and bowel dysfunction in a cat     

Song RB  Cross JR  Golder FJ  Callan MB 《Journal of Feline Medicine and Surgery》2011,13(8):602-605

A 12-year-old male castrated domestic shorthair developed chronic urinary retention, constipation and a decreased perineal reflex following a single lumbo-sacral epidural injection of morphine during general anesthesia. Similar adverse effects have been reported in humans following epidural analgesia, but this is the first reported case of both urinary and bowel dysfunction in a cat purportedly from an epidural. The cat was medically managed with manual bladder expressions, intermittent enemas, and various medications including bethanechol, cisapride and stool softeners. The cat continues to have long-term neurologic dysfunction 15 months post-onset. This case report describes a rare but serious potential risk of lumbo-sacral epidural injections in cats.  相似文献   

Songbird Relationships to Shrub-Steppe Ecological Site Characteristics     

Mary I. Williams  Ginger B. Paige  Thomas L. Thurow  Ann L. Hild  Kenneth G. Gerow 《Strength and Conditioning Journal》2011,64(2):109-118

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High Performance Thin Layer Chromatography (HPTLC) profile of an insecticidal compound of <Emphasis Type="Italic">Trochus radiatus</Emphasis> and assessment of mucus-associated bacterial extracts     

Mary Elizabeth K. Gnanambal  K. C. Ramya Devi  P. Hareesh Chandra  Edward J. K. Patterson 《Phytoparasitica》2011,39(2):121-127

The current study is based on the screening of novel insecticides from new sources that have not being exploited hitherto. The major objectives of this research work were to extract marine molluscs, Lambis lambis, Trochus radiatus and Chicoreus ramosus, from Tuticorin coastal waters using different solvents to test their insecticidal properties and partially purify the active components. The ethyl acetate extracts of L. lambis and T. radiatus showed 100% mortality of Sitophilus oryzae, at a concentration of 200 μg ml⁻¹. The LC₅₀ values for ethyl acetate extracts of L. lambis, T. radiatus and C. ramosus were found to be 67.08, 348.86 and 571.42 μg ml⁻¹, respectively. With regard to bacterial metabolites, at a concentration of 200 μg ml⁻¹ the ethyl acetate extract of A3 was able to elicit an activity of 40% and that of strain A1 – 20%. The LC₅₀ values of the bacterial metabolites were also investigated. Upon chromatographic separation of active ethyl acetate extracts of T. radiatus, the 100% methanol column-purified fraction was found to have an activity of 30% at a concentration of 10 μg against S. oryzae. The purity of the partially pure active compound was observed to be 72.78% on analysis with high pressure thin layer chromatography.  相似文献   

A study of the gaseous and particulate pollutants in the environment of a thermal power plant project area     

L. T. Khemani  M. S. Naik  G. A. Momini  Krishnanand  S. D. Kachre  A. Mary Selvam  Bh. V. Ramana Murty 《Water, air, and soil pollution》1980,13(3):303-316

Observations on gaseous and particulate pollutants were undertaken at four locations in the region of a thermal power plant (TPP), which is under construction at Tuticorin, south India. The predicted concentrations Of SO₂ due to the emissions from the TPP and its possible impact on the inhabitants and climate in the downwind region were evaluated. Also, the predicted concentrations downwind of a Petrochemical Industrial Complex (PIC) located in the vicinity of the TPP were computed and compared with the measured concentrations. The predicted maximum concentration of SO₂ at 6 km downwind of TPP is about 530 μg m^?3 under most favourable wind conditions. The anticipated increase in SO₂ due to the thermal power plant under construction may therefore be substantial. The predicted concentrations Of SO₂, at a distance of 1.8 km downwind of the PIC, varied between 34 and 216 μg m^?3 for wind directions ranging from 70 to 90° and for Pasquill stability category C. The plume would be over the observational site when the wind direction is 80°. The maximum measured concentration was 23 ug m^?3. The discrepancy was due to the rapid fluctuations in the wind direction during the observational period over a wide range from 20 to 90°.  相似文献