687 resultados para Environmental education -- Study and teaching (Primary)
Resumo:
Higher resolution time-stratigraphic records suggest correlation of lower frequency paleoclimatic events with Milankovitch obliquity/precessional cycles and of higher frequency events with the evidently resonance-related Pettersson maximum tidal force (MTF) model. Subsequently published records, mainly pollen, seemingly confirm that atmospheric resonances may have modulated past climatic changes in phase with average MTF cycles of 1668, 1112, and 556 years, as calculated in anomalistic years from planetary movements by Stacey. Stacey accepts Pettersson's dating of AD 1433 (517 YBP) for the last major perihelian spring tide based solely on calculations of moon- and earth-orbital relations to the sun. Use of AD 1433 as an origin for the tidal resonance model seemingly continues to provide a best fit for the timing of cyclical patterns in the presented paleoclimate time series.
Resumo:
The different morphometric characters of Therapon jarbua showed a linear relationship and uniformity in the various biometric measurements whereas the length-weight relationship showed a curvilinear graph. The studies also indicate that there is no significant difference, in the morphometric characters and length-weight relationship between the males and females. Ponderal index values for males and females was found to fluctuate between 1.3 to 1.5 for most of their life times with the peaks and crests appearing at different lengths for males and females.
Resumo:
A novel short neurotoxin, cobrotoxin c (CBT C) was isolated from the venom of monocellate cobra (Naja kaouthia) using a combination of ion-exchange chromatography and FPLC. Its primary structure was determined by Edman degradation. CBT C is composed of 61 amino acid residues. It differs from cobrotoxin b (CBT B) by only two amino acid substitutions, Thr/Ala11 and Arg/Thr56, which are not located on the functionally important regions by sequence similarity. However, the LD50 is 0.08 mg/g to mice, i.e. approximately five-fold higher than for CBT B. Strikingly, a structure-function relationship analysis suggests the existence of a functionally important domain on the outside of Loop III of CBT C. The functionally important basic residues on the outside of Loop III might have a pairwise interaction with alpha subunit, instead of gamma or delta subunits of the nicotinic acetylcholine receptor (nAChR). (C) 2002 Elsevier Science Inc. All rights reserved.
Resumo:
Fish sauce is a popular fermented product used in south Asian countries which is made from different small fishes in this research work it was attempted to produce fish sauce from kilka of the Caspian sea, the fish sauce was made from three models of kilka ,such as whole kilka , cooked whole kilka and dressed kilka , each of these models treated it four different fashions of fermentation such as:1- Traditional method, 2- Enzymatic method 3- Microbial method, 4- Mixture of enzyme and microb The results of this investigation showed that time of fermentation for the traditional method was six month, enzymatic method one month, microbial method 3 month and the mixture of enzyme and microb 1 month. The rate of fermentation was least for dressed Kilka, microbial and biochemical changes of Kilka fish sauce were evaluated, total bacterial count was 2.1-6.15 log cfu/ml total volatile nitrogen (TVN) in samples recorded was 250 mg /100g, the amount of protein varied between 10-13 percent, the name of commercial enzymes added was Protamex and Flavourzyme, the bacteria added was L act ob acillus and Pediococous, fish sauce containers fish and 20% salt, temperature of keeping for fermentation was 37 degree c for 6 month.
Resumo:
Using bioinformatics approach, the genome locus containing interleukin (IL)-22, IL-26, and interferon gamma (IFN-gamma) genes has been identified in the amphibian, Xenopus tropicalis. Like that in other vertebrates such as fish, birds, and mammals, the Xenopus IL-22, IL-26, and IFN-gamma are clustered in the same chromosome and the adjacent genes are conserved. The genomic structures of the Xenopus IL-22, IL-26, and IFN-gamma gene were identical to that of their mammalian counterparts. The Xenopus IL-22 and IL-26 genes contained five exons and four introns while the Xenopus IFN-gamma gene consisted of four exons and three introns. The Xenopus IL-22, IL-26, and IFN-gamma share 14.1-41.6%, 14.6-31.2%, and 23.7-36.5% identity to their counterparts in other species, respectively. Reverse-transcription polymerase chain reaction (PCR) and real-time quantitative PCR analyses revealed that the expression of IL-22, IL-26, and IFN-gamma genes was significantly upregulated after simulation with bacterial polyliposaccharide and/or synthetic double-stranded poly(I:C), suggesting these cytokines like those in other vertebrates play an important role in regulating immune response in Xenopus.
Resumo:
The Raman back scattering/channeling technique was used to analyze the damage recovery at different annealing temperatures and to determine the lattice location of the Er-implanted GaN samples. A better damage recovery was observed with increasing annealing temperature below 1000degreesC, but a complete recovery of the implantation damage cannot be achieved. For a sample annealed for at 900degreesC 30 min the Er and Ga angular scans across the <0001> axis was measured indicating that about 76% of Er ions occupies substitutional sites. Moreover, the photoluminscence (PL) properties of Er-implanted GaN thin films have been also studied. The experimental results indicate that those samples annealed at a higher temperature below 1000degreesC had a stronger 1539nm PL intensity. The thermal quenching of PL intensity for samples annealed at 900degreesC measured at temperatures from 15K to 300K is 30%.
Resumo:
The heat capacities of berberine sulphate [(C20H18NO4)(2)SO4.3H(2)O] were measured from 80 to 390 K by means of an automated adiabatic calorimeter. Smoothed heat capacities,{H-T-H-298.15} and {S-T-S-298.15} were calculated. The loss of crystalline water started at about 339.3+/-0.2 K, and its peak temperature was 365.8+/-0.6 K. The peak temperature of decomposition for berberine sulphate was at about 391.4+/-0.4 K by DSC curve. TG-DTG analysis of this material was carried out in temperature range from 310 to 970 K. TG and DSC curves show that there is no melting in the whole heating process.