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21.
22.
In grasses grown for production of seed under field conditions,it has been found that only a small proportion of tillers produceinflorescences. For a period of 23 weeks from 4 February 1963a study was made of cocksfoot grown for production of seed inan attempt to discern whether the ability of tillers to becomereproductive was related to specific morphological features.Most tillers which initiated spikelets were rooted, and rootsquickly developed on unrooted tillers which had initiated spikelets.It appeared that larger tillers, judged on the basis of dry-weight,were more likely to become fertile than smaller tillers; importantfeatures of tiller size were the length of the stem and theweight of green leaf (lamina) borne by the tiller. The potentialnumber of inflorescences was reduced considerably by the death,in June, of tillers with completely differentiated apices. 相似文献
23.
Changes in odor quality discrimination following recovery from olfactory nerve transection 总被引:4,自引:2,他引:2
Following recovery from olfactory nerve transection, animals regain their
ability to discriminate between odors. Odor discrimination is restored
after new neurons establish connections with the olfactory bulb. However,
it is not known if the new connections alter odor quality perception. To
address this question, 20 adult hamsters were first trained to discriminate
between cinnamon and strawberry odors. After reaching criterion (> or =
90% correct response), half of the animals received a bilateral nerve
transection (BTX) and half a surgical sham procedure. Animals were not
tested again until day 40, a point in recovery when connections are
re-established with the bulb. When BTX animals were tested without food
reinforcement, they could not perform the odor discrimination task. Sham
animals, however, could discriminate, demonstrating that the behavioral
response had not been extinguished during the 40 day period. When
reinforcement was resumed, BTX animals were able to discriminate between
cinnamon and strawberry after four test sessions. In addition, their
ability to discriminate between these two familiar odors was no different
than that of BTX and sham animals tested with two novel odors, baby powder
and coffee. These findings suggest that, after recovery from nerve
transection, there are alterations in sensory perception and that
restoration of odor quality discrimination requires that the animal must
again learn to associate individual odor sensations with a behavioral
response.
相似文献
24.
Juliana M Sousa-Canavez Flavio C Canavez Kátia RM Leite Luiz H Camara-Lopes 《Genetic vaccines and therapy》2008,6(1):1-7
Background
Electroporation is an established technique for enhancing plasmid delivery to many tissues in vivo, including the skin. We have previously demonstrated efficient delivery of plasmid DNA to the skin utilizing a custom-built four-plate electrode. The experiments described here further evaluate cutaneous plasmid delivery using in vivo electroporation. Plasmid expression levels are compared to those after liposome mediated delivery.Methods
Enhanced electrically-mediated delivery, and less extensively, liposome complexed delivery, of a plasmid encoding the reporter luciferase was tested in rodent skin. Expression kinetics and tissue damage were explored as well as testing in a second rodent model.Results
Experiments confirm that electroporation alone is more effective in enhancing reporter gene expression than plasmid injection alone, plasmid conjugation with liposomes followed by injection, or than the combination of liposomes and electroporation. However, with two time courses of multiple electrically-mediated plasmid deliveries, neither the levels nor duration of transgene expression are significantly increased. Tissue damage may increase following a second treatment, no further damage is observed after a third treatment. When electroporation conditions utilized in a mouse model are tested in thicker rat skin, only higher field strengths or longer pulses were as effective in plasmid delivery.Conclusion
Electroporation enhances reporter plasmid delivery to the skin to a greater extent than the liposome conjugation method tested. Multiple deliveries do not necessarily result in higher or longer term expression. In addition, some impact on tissue integrity with respect to surface damage is observed. Pulsing conditions should be optimized for the model and for the expression profile desired. 相似文献25.
J.L. LAMBERT A. LE-BAIL R. ZUNIGA I. VAN-HAESENDONCK E. VNZEVEREN C. PETIT M.C. ROSELL C. COLLAR D. CURIC I. COLIC-BARIC M. SIKORA R. ZIOBRO 《Journal of sensory studies》2009,24(2):204-219
This survey concerns industrial bread making and has been carried out within the European project entitled EU-FRESHBAKE (October 2006 to October 2009), which concerns the bake-off technology. This technology consists in producing bread at industrial level (frozen most of the time) and to retail the bread in "baking stations" or in small vending shops.
The objectives of this survey were (1) to better understand the attitude of the European innovations in bread and (2) to understand the main determinants of it. Two main categories of consumers were observed; (1) frequent (daily) buyers with a focus on quality and pleasure and (2) less frequent buyers (once a week) with a more pronounced interest in nutrition, shelf life and energy (process). The first group was named the "crust group" and the second one the "crumb group." The "crumb group" seems to be the one that is the most interested in the outcomes of the EU-FRESHBAKE project.
This survey brings interesting information regarding the expectations of EU consumers toward innovation in bread making. Bread is a very symbolic food, carrying a lot of messages coming from religion, social classification and from well being.
Among the key messages to be withdrawn from this survey, it appears that northern and eastern Europe, and also the young population, are expecting from bread a food that must adapt to the constrain of life. It must have a long shelf life and it must carry a nutritional value. On the other hand, French and southern Europe countries are bringing more attention to the pleasure and to the freshness of the product. There is thus a complex matrix of social and qualitative attitudes toward bread from one country to the other. Innovation can be considered as a positive image in some countries, whereas it may have a very negative image in other countries. 相似文献
The objectives of this survey were (1) to better understand the attitude of the European innovations in bread and (2) to understand the main determinants of it. Two main categories of consumers were observed; (1) frequent (daily) buyers with a focus on quality and pleasure and (2) less frequent buyers (once a week) with a more pronounced interest in nutrition, shelf life and energy (process). The first group was named the "crust group" and the second one the "crumb group." The "crumb group" seems to be the one that is the most interested in the outcomes of the EU-FRESHBAKE project.
PRACTICAL APPLICATIONS
This survey brings interesting information regarding the expectations of EU consumers toward innovation in bread making. Bread is a very symbolic food, carrying a lot of messages coming from religion, social classification and from well being.
Among the key messages to be withdrawn from this survey, it appears that northern and eastern Europe, and also the young population, are expecting from bread a food that must adapt to the constrain of life. It must have a long shelf life and it must carry a nutritional value. On the other hand, French and southern Europe countries are bringing more attention to the pleasure and to the freshness of the product. There is thus a complex matrix of social and qualitative attitudes toward bread from one country to the other. Innovation can be considered as a positive image in some countries, whereas it may have a very negative image in other countries. 相似文献
26.
Mariana A Antunes Soraia C Abreu Fernanda F Cruz Ana Clara Teixeira Miquéias Lopes-Pacheco Elga Bandeira Priscilla C Olsen Bruno L Diaz Christina M Takyia Isalira PRG Freitas Nazareth N Rocha Vera L Capelozzi Débora G Xisto Daniel J Weiss Marcelo M Morales Patricia RM Rocco 《Respiratory research》2014,15(1)
We sought to assess whether the effects of mesenchymal stromal cells (MSC) on lung inflammation and remodeling in experimental emphysema would differ according to MSC source and administration route. Emphysema was induced in C57BL/6 mice by intratracheal (IT) administration of porcine pancreatic elastase (0.1 UI) weekly for 1 month. After the last elastase instillation, saline or MSCs (1×105), isolated from either mouse bone marrow (BM), adipose tissue (AD) or lung tissue (L), were administered intravenously (IV) or IT. After 1 week, mice were euthanized. Regardless of administration route, MSCs from each source yielded: 1) decreased mean linear intercept, neutrophil infiltration, and cell apoptosis; 2) increased elastic fiber content; 3) reduced alveolar epithelial and endothelial cell damage; and 4) decreased keratinocyte-derived chemokine (KC, a mouse analog of interleukin-8) and transforming growth factor-β levels in lung tissue. In contrast with IV, IT MSC administration further reduced alveolar hyperinflation (BM-MSC) and collagen fiber content (BM-MSC and L-MSC). Intravenous administration of BM- and AD-MSCs reduced the number of M1 macrophages and pulmonary hypertension on echocardiography, while increasing vascular endothelial growth factor. Only BM-MSCs (IV > IT) increased the number of M2 macrophages. In conclusion, different MSC sources and administration routes variably reduced elastase-induced lung damage, but IV administration of BM-MSCs resulted in better cardiovascular function and change of the macrophage phenotype from M1 to M2. 相似文献
27.
Evolution of eutherian cytochrome c oxidase subunit II: heterogeneous rates of protein evolution and altered interaction with cytochrome c 总被引:3,自引:1,他引:2
Cytochrome c oxidase subunit II (COII), encoded by the mitochondrial
genome, exhibits one of the most heterogeneous rates of amino acid
replacement among placental mammals. Moreover, it has been demonstrated
that cytochrome c oxidase has undergone a structural change in higher
primates which has altered its physical interaction with cytochrome c. We
collected a large data set of COII sequences from several orders of mammals
with emphasis on primates, rodents, and artiodactyls. Using phylogenetic
hypotheses based on data independent of the COII gene, we demonstrated that
an increased number of amino acid replacements are concentrated among
higher primates. Incorporating approximate divergence dates derived from
the fossil record, we find that most of the change occurred independently
along the New World monkey lineage and in a rapid burst before apes and Old
World monkeys diverged. There is some evidence that Old World monkeys have
undergone a faster rate of nonsynonymous substitution than have apes. Rates
of substitution at four-fold degenerate sites in primates are relatively
homogeneous, indicating that the rate heterogeneity is restricted to
nondegenerate sites. Excluding the rate acceleration mentioned above,
primates, rodents, and artiodactyls have remarkably similar nonsynonymous
replacement rates. A different pattern is observed for transversions at
four-fold degenerate sites, for which rodents exhibit a higher rate of
replacement than do primates and artiodactyls. Finally, we hypothesize
specific amino acid replacements which may account for much of the
structural difference in cytochrome c oxidase between higher primates and
other mammals.
相似文献
28.
Relationships among msx gene structure and function in zebrafish and other vertebrates 总被引:6,自引:2,他引:4
Ekker M; Akimenko MA; Allende ML; Smith R; Drouin G; Langille RM; Weinberg ES; Westerfield M 《Molecular biology and evolution》1997,14(10):1008-1022
The zebrafish genome contains at least five msx homeobox genes, msxA, msxB,
msxC, msxD, and the newly isolated msxE. Although these genes share
structural features common to all Msx genes, phylogenetic analyses of
protein sequences indicate that the msx genes from zebrafish are not
orthologous to the Msx1 and Msx2 genes of mammals, birds, and amphibians.
The zebrafish msxB and msxC are more closely related to each other and to
the mouse Msx3. Similarly, although the combinatorial expression of the
zebrafish msx genes in the embryonic dorsal neuroectoderm, visceral arches,
fins, and sensory organs suggests functional similarities with the Msx
genes of other vertebrates, differences in the expression patterns preclude
precise assignment of orthological relationships. Distinct duplication
events may have given rise to the msx genes of modern fish and other
vertebrate lineages whereas many aspects of msx gene functions during
embryonic development have been preserved.
相似文献
29.
Ingestion of tolbutamide (Orinase(R)) by nondiabetic humans brought about a maximum reduction in blood sugar within one to two hours. In diabetic persons taking large doses of insulin, or who needed insulin for control, hyperglycemia, ketosis, and increased excretion of glucose in the urine developed when tolbutamide was substituted for insulin or was used before insulin therapy was begun. The only serious toxic manifestation observed was a skin rash in two patients. Successful control of diabetes with tolbutamide was limited to cases in which the disease was of mild, stable type and the patient was 40 or more years of age, of normal weight, and with a previous insulin requirement of 5 to 30 units per day. It was of benefit in 43.5 per cent of all diabetic patients in the series studied and in about 75 per cent of the group that might be referred to as selected. The duration of the disease and the duration of insulin therapy were unimportant in predicting effectiveness for tolbutamide therapy. 相似文献
30.