Comment on the recent COMPASS data on the spin structure function g_1

We examine the recent COMPASS data on the spin structure function g_1 singlet. We show that it is rather difficult to use the data in the present form in order to draw conclusions on the initial parton densities. However, our tentative estimate is that the data better agree with positive rather than negative initial gluon densities.Comment: 8 pages, 1 figur

On the forward-backward charge asymmetry in e+e- -annihilation into hadrons at high energies

The forward-backward asymmetry in e+ e- annihilation into a quark-antiquark pair is considered in the double-logarithmic approximation at energies much higher than the masses of the weak bosons. It is shown that after accounting to all orders for the exchange of virtual photons and W, Z -bosons one is lead to the following effect (asymmetry): quarks with positive electric charge (e.g. u, \bar{d}) tend to move in the e+ - direction whereas quarks with negative charges (e.g. d, \bar{u}) tend to move in the e- - direction. The value of the asymmetry grows with increasing energy when the produced quarks are within a cone with opening angle, in the cmf, \theta_0\sim 2M_Z/\sqrt{s} around the e+e- -beam. Outside this cone, at \theta_0 << \theta << 1, the asymmetry is inversely proportional to \theta .Comment: 17 Pages, 2 Tables, 4 Figures. Hadronization effects to the asymmetry are considered with more detail

Airflow distortion at instrument sites on the RRS James Clark Ross during the WAGES project

Wind speed measurements obtained from anemometers mounted on ships are prone to systematic errors caused by the distortion of the airflow around the ship's hull and superstructure. This report describes the results of simulations of the airflow around the RRS James Clark Ross made using the computational fluid dynamics (CFD) software VECTIS. The airflow distortion at anemometer sites used during the WAGES project has been quantified at a wind speed of 10 m/s for relative wind directions of 0 (bow-on), 10, 20, 30, 50, 70, 90 and 110 degrees off the bow. The anemometers used in this study were located in the bows of the ship. Temperature sensors were located on the port side of the monkey island. For bow-on flows the anemometers in the bows of the ship experienced relatively small flow distortion. At these sites the flow was decelerated by about 1% of the free stream wind speed. Over the full range of relative wind directions the flow to the R3 sonic is generally accelerated with the largest wind speed biases at flows directly over the beam. The vertical displacement of the airflow increases from around 1 to 2 m for flows directly over the bow, to around 5m for flows over the ships beam as the blockage of the airflow by the ship becomes greater.The airflow distortion at the temperature sensor locations above the monkey island was typically greater than the well-exposed foremast locations. These locations experienced wind speed biases from 6% increase for an airflow directly over the bow, to large decelerations of 55 % when the instruments were in the large recirculation region for flows directly over the starboard side

Impact of double-logarithmic electroweak radiative corrections on the non-singlet structure functions at small x

In the QCD context, the non-singlet structure functions of u and d -quarks are identical, save the initial quark densities. Electroweak radiative corrections, being flavor-dependent, bring further difference between the non-singlets. This difference is calculated in the double-logarithmic approximation and the impact of the electroweak corrections on the non-singlet intercepts is estimated numerically.Comment: 17 pages, no figure

Attention modulates the specificity of automatic imitation to human actors

The perception of actions performed by others activates one’s own motor system. Recent studies disagree as to whether this effect is specific to actions performed by other humans, an issue complicated by differences in perceptual salience between human and non-human stimuli. We addressed this issue by examining the automatic imitation of actions stimulated by viewing a virtual, computer generated, hand. This stimulus was held constant across conditions, but participants’ attention to the virtualness of the hand was manipulated by informing some participants during instructions that they would see a “computer-generated model of a hand,” while making no mention of this to others. In spite of this attentional manipulation, participants in both conditions were generally aware of the virtualness of the hand. Nevertheless, automatic imitation of the virtual hand was significantly reduced––but not eliminated––when participants were told they would see a virtual hand. These results demonstrate that attention modulates the “human bias” of automatic imitation to non-human actors

Perturbative power Q^2-corrections to the structure function g(1)

We prove that regulating infrared divergencies generates power (~1/(Q^2)^k) corrections to the spin structure function g_1 at small x and large Q^2. At the same time it leads to the corrections ~(Q^2)^k at small Q^2. We present the explicit series of such terms as well as the formulae for their resummation. These contributions are not included in the standard analysis of the experimental data. We argue that accounting for such terms can sizably change the impact of the other power corrections conventionally attributed to the higher twists.Comment: Theoretical grounds for our approach are considered in much more detailed way than in the previous version; 10 pages, 2 figure

Metadata for the WAGES instrumentation deployed on the James Clark Ross between May 2010 and September 2011

The RRS James Clark Ross makes meteorological measurements around Antarctica during the austral summer, in the Arctic during the boreal summer and in the Atlantic during passages between the two poles. In May 2010, as part of the WAGES project the ships existing systems were complemented by the AutoFlux system (Yelland et al., 2009) to measure the transfers of momentum, heat and CO2 between the atmosphere and the ocean. Similarly, a commercial directional wave radar "WAVEX" made by the Norwegian firm MIROS was installed.This report describes the metadata for the WAGES instrumentation deployed on the RRS James Clark Ross between May 2010 and September 2011. Sensor serial numbers, dates of sensor changes andproblems with sensors are contained in the associated tables

Aquaculture research: technology transfer for rural development in Nigeria

Conventional aquaculture has been promoted in Nigeria for the past five decades with minimal impact on rural communities: from the findings of Maclearen (1949) where he popularized the use of culturable fish predators Lutjanus sp; Pomades sp; Tarpon adanticus; Chrysichthys nigrodigitatus in earthen ponds near Onikan-Lagos, Nigeria; to the finding of Zwilling, 1963, who reported common carp, Cyprinus carpio propagation and culture in Panyan Fish Farm, near Jos; to the findings of FAO, 1965, when the potential culture of marine mullets culture in brackish water ponds in Buguma, Rivers State was presented. The work of other researchers Sivalingam, (1970; 1973), Ezenwa (1976), development officers and extension officers contributed to the development of aquaculture in few rural areas of the country and informed on public and private owned fish farm infrastructures. Despite a moderate long history of aquaculture research and development in Nigeria, an annual production level of 25,000 metric tons was recorded in 1999. This situation calls for a more sustainable approach for a stronger link between aquaculture research and technology transfer for the development of rural communities of Nigeria. This paper therefore examines some of the issues involved in the continuous flow of the new aquaculture technology in the improvement of fish protein output, standard of living of rural farmers and prevention of urban migration by the yout

Metadata for the WAGES instrumentation deployed on the RRS James Clark Ross between May 2010 and September 2013

The RRS James Clark Ross makes meteorological measurements around Antarctica during the austral summer, in the Arctic during the boreal summer and in the Atlantic during passages between the two poles. In May 2010, as part of the WAGES project the ships existing systems were complemented by the AutoFlux system (Yelland et al., 2009) to measure the transfers of momentum, heat and CO2 between the atmosphere and the ocean. Similarly, a commercial directional wave radar "WAVEX" made by the Norwegian firm MIROS was installed. This report describes the metadata for the WAGES instrumentation deployed on the RRS James Clark Ross between May 2010 and September 2013. Sensor serial numbers, dates of sensor changes and problems with sensors are contained in the associated tables

Possible biases in wind speed measurements from merchant ships

Wind speed measurements obtained from ship-mounted anemometers are biased by the presence of the ship which distorts the airflow to the anemometer. Until recently this bias had only been quantified for a few well-exposed anemometer sites on individual research ships, whereas the magnitude and even the sign of the bias was unknown for anemometers on merchant ships. Three-dimensional numerical simulations of the airflow over a typical tanker/bulk carrier have been performed to quantify the pattern of the airflow above the ship’s bridge. The accuracy of the numerical simulations has been verified by comparison to wind tunnel studies. Typically, the flow is accelerated by up to 18±6 % or decelerated by 100% depending on position. In practice, an anemometer located above the bridge should be mounted as high and as far forwards as possible