The Ramanujan conjecture and its applications.

In this paper, we review the Ramanujan conjecture in classical and modern settings and explain its various applications in computer science, including the explicit constructions of the spectrally extremal combinatorial objects, called Ramanujan graphs and Ramanujan complexes, points uniformly distributed on spheres, and Golden-Gate Sets in quantum computing. The connection between Ramanujan graphs/complexes and their zeta functions satisfying the Riemann hypothesis is also discussed. This article is part of a discussion meeting issue 'Srinivasa Ramanujan: in celebration of the centenary of his election as FRS'.

Impact of a pharmacy-led smoking cessation clinic in a dermatology centre

INTRODUCTION@#Cigarette smoking is a leading cause of morbidity and mortality, and has a deleterious effect on dermatological conditions, such as skin cancers, hidradenitis suppurativa and psoriasis. The study aimed to evaluate the efficacy of a pharmacist-led smoking cessation clinic in reducing cigarette smoking at a tertiary referral dermatology centre. We described the impact of this clinic to provide guidance on how such a model could be further improved and implemented more widely.@*METHODS@#In this single-centre, retrospective study, 74 currently smoking patients who received counselling at a structured smoking cessation clinic between January 2010 and March 2013 were identified. Information on baseline demographic characteristics and detailed past medical history, including smoking history, was collected. Follow-up was conducted at two weeks and three months.@*RESULTS@#At the first follow-up at two weeks, which was attended by 57 patients, 9 (15.8%) had stopped smoking and 26 (45.6%) showed reduction in the number of cigarette sticks smoked per day, with an average reduction of 4.1 cigarette sticks per day. However, a few patients also reported no change or increased number of cigarette sticks smoked per day following counselling.@*CONCLUSION@#A structured pharmacist-led smoking cessation clinic is effective and can be made a part of the holistic management of dermatological conditions.

Protein kinase A(PKA)-restrictive and PKA-permissive phases of oocyte maturation.

Substantial evidence has indicated that cAMP-dependent protein kinase (protein kinase A or PKA) plays a critical role in maintaining meiotic prophase arrest in vertebrate oocytes. However, PKA activity dynamic and its physiological substrate profile during oocyte maturation remain poorly defined. We have recently developed a novel PKA substrate construct which we employ to monitor PKA activity in live oocytes. We demonstrated here that, during progesterone-induced oocyte maturation, PKA was inactivated within 30 min of the addition of progesterone and thereafter remained inactivated throughout the entire maturation process. However, artificial reactivation of endogenous PKA had differential consequences, depending on the timing of PKA reactivation. Reactivation of endogenous PKA at any time prior to germinal vesicle breakdown (GVBD) inhibited progesterone-induced GVBD. PKA reactivation at GVBD, or thereafter, did not interfere with meiosis I to meiosis II transition, nor did it interfere with metaphase II arrest. These results demonstrate for the first time a PKA-restrictive and a PKA-permissive phase in oocyte maturation.