Evaluation of slope stability through rock mass classification and kinematic analysis of some major slopes along NH-1A from Ramban to Banihal, North Western Himalayas

The network of Himalayan roadways and highways connects some remote regions of valleys or hill slopes,which is vital for India’s socio-economic growth.Due to natural and artificial factors,frequency of slope instabilities along the networks has been increasing over last few decades.Assessment of stability of natural and artificial slopes due to construction of these connecting road networks is significant in safely executing these roads throughout the year.Several rock mass classification methods are generally used to assess the strength and deformability of rock mass.This study assesses slope stability along the NH-1A of Ramban district of North Western Himalayas.Various structurally and non-structurally controlled rock mass classification systems have been applied to assess the stability conditions of 14 slopes.For evaluating the stability of these slopes,kinematic analysis was performed along with geological strength index(GSI),rock mass rating(RMR),continuous slope mass rating(CoSMR),slope mass rating(SMR),and Q-slope in the present study.The SMR gives three slopes as completely unstable while CoSMR suggests four slopes as completely unstable.The stability of all slopes was also analyzed using a design chart under dynamic and static conditions by slope stability rating(SSR)for the factor of safety(FoS)of 1.2 and 1 respectively.Q-slope with probability of failure(PoF)1%gives two slopes as stable slopes.Stable slope angle has been determined based on the Q-slope safe angle equation and SSR design chart based on the FoS.The value ranges given by different empirical classifications were RMR(37-74),GSI(27.3-58.5),SMR(11-59),and CoSMR(3.39-74.56).Good relationship was found among RMR&SSR and RMR&GSI with correlation coefficient(R 2)value of 0.815 and 0.6866,respectively.Lastly,a comparative stability of all these slopes based on the above classification has been performed to identify the most critical slope along this road.

Nicotinamide adenine dinucleotide replenishment rescues colon degeneration in aged mice

Susceptibility of gastrointestinal dysmotility increases with age-associated colonic degeneration.A paucity of remedies reversing colonic degeneration per se hinders the fundamental relief of symptoms.Here we discovered the correlation between colon degeneration and altered nicotinamide adenine dinucleotide(NAD)level in aged mice.Compared to 3-month-old young controls,2-year-old mice showed a spectrum of degenerative colonic phenotypes and exhibited a significant elongated transit time and slowed stool frequency in the context of Lomotil-induced slow-transit constipation.Despite upregulated colonic tryptophan hydroxylases expression,serotonin release and expression of colon-predominant type IV serotonin receptor,reduced viability of interstitial cells of Cajal while enhanced aquaporins(Aqp1,3 and 11)led to a less colonic motility and increased luminal dehydration in aged mice.Notably,this colonic degeneration was accompanied with reduced key NAD^(+)-generating enzyme expression and lowered NAD^(+)/NADH ratio in aged colon.Three-month continuous administration of beta nicotinamide mononucleotide,a NAD^(+)precursor,elevated colonic NAD^(+)level and improved defecation in aged mice.In contrast,pharmacological inhibition of nicotinamide phosphoribosyltransferase,the rate-limiting enzyme for NAD^(+)biosynthesis,induced a reduction in colonic NAD content and impaired gastrointestinal function in young mice.Taken together,these findings suggest the beneficial effect of NAD^(+)in maintaining colonic homoeostasis and reactivating NAD^(+)biosynthesis may represent a promising strategy to counteract age-related gastrointestinal degeneration.