Principles of sensorimotor learning.

The exploits of Martina Navratilova and Roger Federer represent the pinnacle of motor learning. However, when considering the range and complexity of the processes that are involved in motor learning, even the mere mortals among us exhibit abilities that are impressive. We exercise these abilities when taking up new activities - whether it is snowboarding or ballroom dancing - but also engage in substantial motor learning on a daily basis as we adapt to changes in our environment, manipulate new objects and refine existing skills. Here we review recent research in human motor learning with an emphasis on the computational mechanisms that are involved

H9N2 avian influenza virus antibody titers in human population in fars province, Iran

Among the avian influenza A virus subtypes, H5N1 and H9N2 viruses have the potential to cause an influenza pandemic because they are widely prevalent in avian species in Asia and have demonstrated the ability to infect humans. This study was carried out to determined the seroprevalence of H9N2 avian influenza virus in different human populations in Fars province, which is situated in the south of Iran. Antibodies against H9N2 avian influenza virus were measured using hemagglutination-inhibition (HI) test in sera from 300 individuals in five different population in Fars province, including poultry-farm workers, slaughter-house workers, veterinarians, patients with clinical signs of respiratory disease, and clinically normal individuals, who were not or rarely in contact with poultry. Mean antibody titers of 7.3, 6.8, 6.1, 4.5, and 2.9 and seroprevalences of 87%, 76.2%, 72.5%, 35.6%, and 23% were determined in those groups, respectively. Higher prevalences were detected in poultry-farm workers, slaughter-house workers, and veterinarians, possibly due to their close and frequent contact with poultry

Tuning of metal work functions with self-assembled monolayers

Tuning the work functions of metals was demonstrated by chemically modifying the metal surface through the formation of chemisorbed self-assembled monolayers (SAMs) derived from 1H,1H,2H,2H-perfluorinated alkanethiols and hexadecanethiol. The ordering inherent in the SAMs creates an effective, molecular dipole at the metal/SAM interface, which increased the work function of Ag (Phi(Ag) similar to 4.4 eV) to 5.5 eV (DeltaPhi similar to 1.1 eV) for 1H,1H,2H,2H-perfluorinated alkanethiols. Hexadecanethiol on the other hand shifted Phi(Ag) toward 3.8 eV (DeltaPhi similar to 0.6 eV) and raised the energy barrier for hole injection. These SAMs on Au were less efficient. 1H,1H,2H,2H-perfluorodecanethiol raised Phi(Ag) (4.9 eV) by 0.5 eV to 5.4 eV, whereas hexadecanethiol decreased DeltaPhi by only 0.1 eV. These chemically modified electrodes were applied in the fabrication of pLEDs and the hole conduction of MEH-PPV was investigated. An ohmic contact for hole injection between a silver electrode functionalized with the perfluorinated SAMs, and MEH-PPV with a HOMO of 5.2 eV was established. Conversely, a silver electrode modified with a SAM of hexadecanethiol lowered Phi(Ag) to 3.8 eV, creating an efficient energy barrier for hole injection. This method demonstrates a simple and attractive approach to modify and improve metal/organic contacts in organic electronic devices like LEDs and photovoltaic cells