Quantum searching amidst uncertainty

Consider a database most of whose entries are marked but the precise fraction of marked entries is not known. What is known is that the fraction of marked entries is 1-X, where X is a random variable that is uniformly distributed in the range (0,X_0) (X_0 is a small number). The problem is to try to select a marked item from the database in a single query. If the algorithm selects a marked item, it succeeds, else if it selects an unmarked item, it makes an error. How low can we make the probability of error? The best possible classical algorithm can lower the probability of error to O((X_0)^2). The best known quantum algorithms for this problem could also only lower the probability of error to O((X_0)^2). Using a recently invented quantum search technique, this paper gives an algorithm that reduces the probability of error to O((X_0)^3). The algorithm is asymptotically optimal.Comment: 10 page

Prenatal Nicotine Exposure as a Teratogen in Neurological Pathways

Attention-deficit/hyperactivity disorder (ADHD) is the most heritable and commonly diagnosed childhood psychiatric disorder with 4% of all children being diagnosed with this disorder. Prenatal smoking has been found to be a risk factor for ADHD, a disorder that has been believed to be linked to the fluctuation of dopamine levels. Prenatal nicotine exposure in the second trimester influences dopaminergic neurological pathways by altering dopamine release levels. The altered dopamine levels make the fetus brain more sensitive to the nicotine, causing the nicotine exposure to be more dangerous in causing ADHD symptoms. Prenatal nicotine exposure alters the neurological pathway of the neurotransmitters, ACh and dopamine, not only in the fetus but later in adolescence too. When nicotine enters the body, it is distributed quickly through the bloodstream and into the Central Nervous System (CNS). Cigarette smoke interferes with customary placental function, and therefore the flow of nutrients and oxygen. The nAChRs increases the amount of dopamine released in the synaptic area. Functional changes in DRD4 receptors and in dopamine transporter number caused by genetic variations and prenatal smoking exposure results in changes in dopamine release; however, the relationship between prenatal nicotine exposure and ADHD symptoms was not changed by sociodemographic factors. Interventions should be set-up in order to urge women to quit smoking during their pregnancy. The present study has health significance in that the research will urge pregnant women to be cautious of smoking through proposed interventions

The higher pragmitism

Thesis (M.A.)--Boston Universit