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Cassava is an important food security crop in the developing world, as it is adapted to a wide range of climatic conditions including marginal semi-arid agro-ecologies. Cassava is a starchy staple and the storage roots of commercial cassava cultivar are very low in protein content (0.5–2%, dry weight basis). A diet predominantly based on cassava, as is the case in several sub-Saharan countries, could lead to malnutrition, especially in young children over time. A wild progenitor of cassava, Manihot esculenta ssp. flabellifolia have been found to have high root protein content, up to 18% (dry weight basis) and is excellent source of genetic variability for this important trait. Accessions of M. esculenta ssp. flabellifolia with high storage root protein content were crossed with commercial cassava cultivars. High content of storage root protein ranged from 2.87 to 11.25% could be recovered in the F1 progenies. The F1 families had an average dry matter content of 29.6%. These F1 interspecific hybrids would be an entry point for improvement of cassava storage root protein content. A brief discussion of the strategy to be followed is presented.  相似文献   
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A previously unknown solid phase of H2O has been identified by its peculiar growth patterns, distinct pressure-temperature melting relations, and vibrational Raman spectra. Morphologies of ice crystals and their pressure-temperature melting relations were directly observed in a hydrothermal diamond-anvil cell for H2O bulk densities between 1203 and 1257 kilograms per cubic meter at temperatures between -10 degrees and 50 degreesC. Under these conditions, four different ice forms were observed to melt: two stable phases, ice V and ice VI, and two metastable phases, ice IV and the new ice phase. The Raman spectra and crystal morphology are consistent with a disordered anisotropic structure with some similarities to ice VI.  相似文献   
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The aim of this study was to compare the monoterpene content and distribution in litters and roots of three conifer species: Picea abies (L.) Karst, Picea sitchensis (Bong.) Carr. and Pinus sylvestris (L.). We analysed the monoterpene content of green needles, needle litter, F (fermentation) layer material and roots collected from monoculture plots. The rate of loss of monoterpenes from freshly fallen litter in the field was also studied at two monthly intervals over 10 months, to assess the length of time that monoterpenes entering the litter layer remain. Monoterpene analysis was carried out by extracting homogenised samples in hexane and identifying and quantifying the resulting monoterpenes using gas chromatography with flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Mean total monoterpene concentrations varied significantly between the three species examined (e.g. in freshly fallen litter 1531 ± 96, 100 ± 5 and 1175 ± 122 μg g−1 d. wt for P. abies, P. sitchensis and P. sylvestris); each species had distinctive and consistent monoterpene profiles associated with each type of tissue, and total monoterpene concentrations in green needles varied between individual trees of the same species, particularly for P. sitchensis. A substantial proportion of the monoterpene content of green needles remained in the needles after litter fall for P. abies (42%), P. sitchensis (11%) and P. sylvestris (30%). Although rates of monoterpene loss from needle litters varied initially (P. sylvestris > P. abies > P. sitchensis), the majority of the monoterpene content was lost after 4-6 months. Maximum monoterpene emission rates from decaying litter were calculated of 39 (P. abies), 1.7 (P. sitchensis) and 39 μg m−2 h−1 (P. sylvestris). Monoterpene concentrations in F layer material were very low (<10 μg g−1 d. wt). Roots, particularly in P. sylvestris, represented a significant pool of monoterpenes (185 ± 16, P. abies; 258 ± 54, P. sitchensis; 2133 ± 200 μg g−1 d. wt, P. sylvestris). The monoterpene profile was similar between roots and litter of P. sylvestris (α-pinene most abundant), and for P. sitchensis, (limonene and α-pinene most abundant), although a different pattern was observed between needle litter (most abundant β-pinene) and roots (most abundant myrcene) of P. abies. The relatively high concentrations and different profiles of monoterpenes characterised in upper organic soil horizons here emphasise the need for their influence on soil ecological processes to be assessed.  相似文献   
55.
The precise determination of the embryonic chronology is very important in reproductive biotechnologies, especially in estimating embryonic age. Thus, there is a need for greater knowledge and standardization for determining the chronology of embryonic development and functional morphology. We describe aspects of embryonic development in two domestic carnivores to add knowledge about organ peculiarities and for application in veterinary practice, in prenatal development and in the biotechnology fields. We found that the development of differential characteristics of embryonic organs occurs in the first trimester of pregnancy for both species. Thus, using the combination of the crown‐rump length, macroscopic analysis and optical microscopy, it is possible to predict gestational age more precisely in animals that lack a defined breed and establish an embryonic pattern.  相似文献   
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Abstract

CASE HISTORY: Ovariohysterectomy was performed on an adult Cavalier King Charles Spaniel. The skin that had been clipped for surgery was noticed to be erythematous 8 days later.

CLINICAL AND PATHOLOGICAL FINDINGS: Poorly defined patches containing multiple papules were visible bilaterally within the clipped skin. These became larger over the following 2 weeks, and samples were collected for histology. Seven days later, the lesions were multiple raised masses, up to 5 cm in diameter. Histology revealed numerous cup-shaped epidermal proliferations extending into the dermis. The presence of keratinocytes with increased quantities of blue-grey cytoplasm, and koilocytosis suggested papillomavirul infection; Canis familiaris papillomavirus (CfPV-2) DNA was amplified from two separate samples. Complete regression was observed 8 weeks after the lesions had been initially observed.

DIAGNOSIS: Multiple inverted papilloma confined to skin that had been clipped for surgery.

CLINICAL RELEVANCE: This is the first time that the development of canine cutaneous papillomas has been associated with surgery. The nature of the association between surgery and development of the papillomas is uncertain. However, it is possible that damage to superficial skin could promote the formation of papillomas. This is the first identification of CfPV-2 in New Zealand.  相似文献   
60.
The objectives of this investigation were to understand transplacental transport of iron by secreted uteroferrin (UF) and haemophagous areas of water buffalo placenta and clarify the role(s) of blood extravasation at the placental‐maternal interface. Placentomes and interplacentomal region of 51 placentae at various stages of gestation were fixed, processed for light and transmission electron microscopy, histochemistry and immunohistochemistry. Haemophagous areas were present in placentomes collected between 4 and 10 months of pregnancy. Perl’s reaction for ferric iron was negative in placentomes, but positive in endometrial glands. Positive staining for UF indicated areas in which it was being taken up by phagocytosis and/or fluid phase pinocytosis in areolae of the interplacentomal mesenchyme, with little staining in endometrial stroma. Imunohistochemistry detected UF in trophectoderm of haemophagous regions of placentomes and in other parts of the foetal villous tree, but the strongest immunostaining was in the epithelial cells and lumen of uterine glands. Ultrastructural analyses indicated that erythrophagocytosis was occurring and that erythrocytes were present inside cells of the chorion that also contained endocytic vesicles and caveolae. Results of this study indicate that both the haemophagous areas of placentomes and the areolae at the interface between chorion and endometrial glands are important sites for iron transfer from mother to foetal‐placental tissues in buffalo throughout pregnancy.  相似文献   
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