Overexpression of the type 1 adenylyl cyclase in the forebrain leads to deficits of behavioral inhibition

The type 1 adenylyl cyclase (AC1) is an activity-dependent, calcium-stimulated adenylyl cyclase expressed in the nervous system that is implicated in memory formation. We examined the locomotor activity, and impulsive and social behaviors of AC1+ mice, a transgenic mouse strain overexpressing AC1 in the forebrain. Here we report that AC1+ mice exhibit hyperactive behaviors and demonstrate increased impulsivity and reduced sociability. In contrast, AC1 and AC8 double knock-out mice are hypoactive, and exhibit increased sociability and reduced impulsivity. Interestingly, the hyperactivity of AC1+ mice can be corrected by valproate, a mood-stabilizing drug. These data indicate that increased expression of AC1 in the forebrain leads to deficits in behavioral inhibition

Genetic disruption of the core circadian clock impairs hippocampus-dependent memory

Perturbing the circadian system by electrolytically lesioning the suprachiasmatic nucleus (SCN) or varying the environmental light:dark schedule impairs memory, suggesting that memory depends on the circadian system. We used a genetic approach to evaluate the role of the molecular clock in memory. Bmal1−/− mice, which are arrhythmic under constant conditions, were examined for hippocampus-dependent memory, LTP at the Schaffer-collateral synapse, and signal transduction activity in the hippocampus. Bmal1−/− mice exhibit impaired contextual fear and spatial memory. Furthermore, LTP in hippocampal slices from Bmal1−/− mice is also significantly decreased relative to that from wild-type mice. Activation of Erk1,2 MAP kinase (MAPK) during training for contextual fear memory and diurnal oscillation of MAPK activity and cAMP in the hippocampus is also lost in Bmal1−/− mice, suggesting that the memory defects are due to reduction of the memory consolidation pathway in the hippocampus. We conclude that critical signaling events in the hippocampus required for memory depend on BMAL1

Genetic repression of the antioxidant enzymes reduces the lifespan in Drosophila melanogaster

Aging is a biological process associated with gradual loss of function caused by cellular and molecular damages ultimately leading to mortality. Free radicals are implicated in oxidative damage which affects the longevity of organisms. Natural cellular defenses involving antioxidant enzymes delay or prevent oxidative damage and, therefore, influence the aging process and longevity has been shown in many species including Drosophila. We and others have shown that oxidative resistance is an important mechanism in the aging process in Drosophila. Therefore, we hypothesized that repressing endogenous antioxidant defenses shortens longevity in Drosophila. To study the influence of natural defense mechanisms against oxidative stress in aging, we have investigated the effect of genetic repression of the antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), on longevity in Drosophila using transgenic RNAi flies and in vivo inhibition of the enzymes with chemical inhibitors. RNAi lines of Drosophila viz., UAS-sod1-IR and UAS-cat-IR, are driven ubiquitously using Act5C-Gal4 and Tubulin-Gal4 to achieve the suppression of SOD1 and CAT activities, respectively. We show that genetic repression of SOD1 and CAT by RNAi in transgenic flies led to drastically reduced longevity (SOD1, 77%; CAT, 83%), presenting the evidence for the role of endogenous antioxidant defenses in lifespan extension in Drosophila. Further, our study shows that the enzyme inhibitors, diethyldithiocarbamate and 3-amino-1,2,4-triazole, although lower the enzyme activities in vivo in flies, but did not affect longevity, which could be attributed to the factors such as bioavailability and metabolism of the inhibitors and adaptive mechanisms involving de novo synthesis of the enzymes. Our study of genetic repression using transgenic RNAi provides experimental evidence that extended longevity is associated with endogenous antioxidant defenses and aging is correlated with oxidative stress resistance

Biaxial Flexural Strength and Estimation of Size on the Strength Properties of FRP Composites

Fibre reinforced plastics (FRP) are widely used as structural materials. For designing structural components, a designer is provided with data based on unidirectional testing. But in real structural applications the component is subjected to multiaxial stress throughout the material. Hence a multiaxial test is a better gauge of the behaviour of FRP components in service. In the present paper a ring-on-ring method was adopted which produces biaxial flexural stress on the FRP specimen. Wubull's statistical weakest link theory was applied to standardize the complexity and to assess the reliability of the results

Ballistic Applications of Glass and Kevlar Fibre Vinylester Composites

Void-free E-glass and Kevlar-49 fibre reinforced vinylester laminates prepared under compression moulding were found to have Charpy impact strength of 576 KJlm2 and 304 KJlm2, respectively. Ballistic immunisation tests carried out on the glass reinforced vinylester laminates with thickness ranging from 12 mm to 54 mm against 7.62 mm rifle bullets produced an exponential relationship between the per cent attenuation in bullet velocity and the areal density of the laminates; whereas the relationship was linear for 9 mm carbine fire with laminate thicknessvarying from 5.5 mm to 12 mm

CIRCUMSCRIPTION OF FULBRIGHTIELLA GEN. NOV. AND SHERWOODIELLA GEN. NOV., TWO NOVEL GENERA IN THE CALOTRICHACEAE (NOSTOCALES, CYANOBACTERIA)

Three novel strains in Calotrichaceae from tropical habitats were isolated and characterized with regard to their morphology, phylogenetic placement, and secondary structures of conserved domains in the 16S‐23S internal transcribed spacer (ITS). The strains fell into two clades formerly identified as Calothrix from freshwater and brackish habitats. Based on both morphology and ecology, they differed from the type species of Calothrix, C. confervicola, which is marine, has wide trichomes with short cells, and narrows abruptly to a hyaline hair. The first clade grouped species with heteropolar filaments widened at the base and narrowed gradually toward the apex but not ending in a hair, with basal heterocytes that are formed in series as the apically placed heterocytes senesce; this clade is being named Fulbrightiella gen. nov., with two named species, F. bharadwajae sp. nov. and F. oahuensis sp. nov. The second clade was comprised of a single species with isopolar trichomes that are untapering as hormogonia, but which widen midfilament and taper toward both ends following growth. These trichomes develop pairs of heterocyte mid‐filament, causing fragmentation into heteropolar trichomes with basal heterocytes and ends that taper, but not to a hair. This clade consists of a single species at present, Sherwoodiella mauiensis. With this action, four clades in the Calotrichaceae have been named: Macrochaete, Dulcicalothrix, Fulbrightiella, and Sherwoodiella. Calothrix sensu stricto is truly marine, morphologically distinct, and unsequenced; finding and sequencing the generitype for Calothrix remains as the most important and unfinished task in the revision of the Calotrichaceae

A study on the failure of steel chains in rotary cement kilns

The failure of steel chains which are used in rotary cement kilns costs cement companies a significant price. This study investigated the causes of chains failure at the Kufa cement plant and proposes new materials that can serve for a prolonged period of time. Two grades of steel chains were investigated including DIN 1.4742 (AISI 10F) and St37. Ten samples of chains from different locations from the kiln flame have been taken after 30 days and after 180 days of continuous work inside the rotary cement kiln. To study the effect of the distance from the kiln flame on the DIN 1.4742 (AISI 10F), another two samples have been replaced the St37 grade at a distance of 28.2 m. Chemical analysis for each sample under study has been carried out in order to highlight the differences between the used chain and the original chain in terms of alloying elements weight. An optical images of the unused and used chains of DIN 1.4742 (AISI 10F) steel grade have been taken to understand that the change occurs in the grain size. SEM-EDS technique was also applied to understand the possible segregation of elements. The results showed that the decrease of alloying elements pct, especially Cr, in the microstructure was the main reason of chain failure by corrosion/erosion mechanism. Preventing Cr from segregation can prolong the life of kiln chains during service. The study suggests new steel grades to replace DIN 1.4742 (AISI 10F) and St37 steel grades