Main-streaming participatory and cross-disciplinary approaches in animal science research in developing countries

Conventional research approaches have lost considerable momentum after their astonishing achieve-ments during the green revolution. The negative side of focusing rigorously on production improve-ment was eminent around 1980 and led to considerations of environmental, gender and equity aspects - making agricultural development much more complex than previously. In the search for new ways of addressing the persisting problems of food insecurity and malnutrition, new ways should be explored. Based on the experiences from three international, African research projects, the article argues the case of participatory action research and cross-disciplinarity as some of the key elements in future animal science research in developing countries. The benefits are outlined as well as the challenges for the researchers and the donor agencies

Scanning the phases of QCD with BRAHMS

BRAHMS has the ability to study relativistic heavy ion collisions from the final freeze-out of hadrons all the way back to the initial wave-function of the gold nuclei. This is accomplished by studying hadrons with a very wide range of momenta and angles. In doing so we can scan various phases of QCD, from a hadron gas, to a quark gluon plasma and perhaps to a color glass condensate.Comment: 8 pages, 6 figures, proceedings of plenary talk at Quark Matter 2004 conferenc

High Pt Hadron Spectra at High Rapidity

We report the measurement of charged hadron production at different pseudo-rapidity values in deuteron+gold as well as proton+proton collisions at $sqrt{s_{NN}}$ = 200GeV at RHIC. The nuclear modification factors $R_{dAu}$ and $R_{cp}$ are used to investigate new behaviors in the deuteron+gold system as function of rapidity and the centrality of the collisions respectively.Comment: Nine pages 4 figures to be published in the QM2004 Proceedings, typos corrected and one reference adde

Strings on conifolds from strong coupling dynamics, part I

A method to solve various aspects of the strong coupling expansion of the superconformal field theory duals of AdS_5 x X geometries from first principles is proposed. The main idea is that at strong coupling the configurations that dominate the low energy dynamics of the field theory compactified on a three sphere are given by certain non-trivial semi-classical configurations in the moduli space of vacua. We show that this approach is self-consistent and permits one to express most of the dynamics in terms of an effective N=4 SYM dynamics. This has the advantage that some degrees of freedom that move the configurations away from moduli space can be treated perturbatively, unifying the essential low energy dynamics of all of these theories. We show that with this formalism one can compute the energies of strings in the BMN limit in the Klebanov-Witten theory from field theory considerations, matching the functional form of results found using AdS geometry. This paper also presents various other technical results for the semiclassical treatment of superconformal field theories.Comment: 52 pages, JHEP3 styl

Charged particle densities from Au+Au collisions at sqrt{s_{NN}}=130 GeV

We present charged particle densities as a function of pseudorapidity and collision centrality for the 197Au+197Au reaction at sqrt{s_{NN}}=130 GeV. An integral charged particle multiplicity of 3860+/-300 is found for the 5% most central events within the pseudorapidity range -4.7 <= eta <= 4.7. At mid-rapidity an enhancement in the particle yields per participant nucleon pair is observed for central events. Near to the beam rapidity, a scaling of the particle yields consistent with the ``limiting fragmentation'' picture is observed. Our results are compared to other recent experimental and theoretical discussions of charged particle densities in ultra-relativistic heavy-ion collisions.Comment: 14 pages, 4 figures; to be published in Phys. Lett.

Nuclear Modification Factor for Charged Pions and Protons at Forward Rapidity in Central Au+Au Collisions at 200 GeV

We present spectra of charged pions and protons in 0-10% central Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV at mid-rapidity ($y=0$) and forward pseudorapidity ($\eta=2.2$) measured with the BRAHMS experiment at RHIC. The spectra are compared to spectra from p+p collisions at the same energy scaled by the number of binary collisions. The resulting nuclear modification factors for central Au+Au collisions at both $y=0$ and $\eta=2.2$ exhibit suppression for charged pions but not for (anti-)protons at intermediate $p_T$. The $\bar{p}/\pi^-$ ratios have been measured up to $p_T\sim 3$ GeV/$c$ at the two rapidities and the results indicate that a significant fraction of the charged hadrons produced at intermediate $p_T$ range are (anti-)protons at both mid-rapidity and $\eta = 2.2$

Forward and midrapidity like-particle ratios from p+p collisions at sqrt(s)=200 GeV

We present a measurement of pi-\pi+, K-/K+ and pbar/p from p+p collisions at sqrt(s) = 20 0GeV over the rapidity range 0<y<3.4. For pT < 2.0 GeV/c we see no significant transverse momentum dependence of the ratios. All three ratios are independent of rapidity for y ~< 1.5 and then steadily decline from y ~ 1.5 to y ~ 3. The pi-\pi+ ratio is below unity for y > 2.0. The pbar/p ratio is very similar for p+p and 20% central Au+Au collisions at all rapidities. In the fragmentation region the three ratios seem to be independent of beam energy when viewed from the rest frame of one of the protons. Theoretical models based on quark-diquark breaking mechanisms overestimate the pbar/p ratio up to y ~< 3. Including additional mechanisms for baryon number transport such as baryon junctions leads to a better description of the data.Comment: 15 pages, 4 figures, uses elsart.sty. Changes to references and discussion based on referee comments, resubmitted to Phys. Lett.

The New Physics at RHIC. From Transparency to High pt_t Suppression

Heavy ion collisions at RHIC energies (Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV) exhibit significant new features as compared to earlier experiments at lower energies. The reaction is characterized by a high degree of transparency of the collisions partners leading to the formation of a baryon-poor central region. In this zone, particle production occurs mainly from the stretching of the color field. The initial energy density is well above the one considered necessary for the formation of the Quark Gluon Plasma, QGP. The production of charged particles of various masses is consistent with chemical and thermal equilibrium. Recently, a suppression of the high transverse momentum component of hadron spectra has been observed in central Au+Au collisions. This can be explained by the energy loss experienced by leading partons in a medium with a high density of unscreened color charges. In contrast, such high $p_t$ jets are not suppressed in d+Au collisions suggesting that the high $p_t$ suppression is not due to initial state effects in the ultrarelativistic colliding nuclei.Comment: 15 pages, 11 figures. to appear in Nucl. Physics A. Invited talk at 'Nucleus-Nucleus Collisions 2003' conference, Mosco

Assessment of IgG-Fc glycosylation from individual RhD-specific B cell clones reveals regulation at clonal rather than clonotypic level

The type and strength of effector functions mediated by immunoglobulin G (IgG) antibodies rely on the subclass and the composition of the N297 glycan. Glycosylation analysis of both bulk and antigen-specific human IgG has revealed a marked diversity of the glycosylation signatures, including highly dynamic patterns as well as long-term stability of profiles, yet information on how individual B cell clones would contribute to this diversity has hitherto been lacking. Here, we assessed whether clonally related B cells share N297 glycosylation patterns of their secreted IgG. We differentiated single antigen-specific peripheral IgG+ memory B cells into antibody-secreting cells and analysed Fc glycosylation of secreted IgG. Furthermore, we sequenced the variable region of their heavy chain, which allowed the grouping of the clones into clonotypes. We found highly diverse glycosylation patterns of culture-derived IgG, which, to some degree, mimicked the glycosylation of plasma IgG. Each B cell clone secreted IgG with a mixture of different Fc glycosylation patterns. The majority of clones produced fully fucosylated IgG. B cells producing afucosylated IgG were scattered across different clonotypes. In contrast, the remaining glycosylation traits were, in general, more uniform. These results indicate IgG-Fc fucosylation to be regulated at the single-clone level, whereas the regulation of other glycosylation traits most likely occurs at a clonotypic or systemic level. The discrepancies between plasma IgG and culture-derived IgG, could be caused by the origin of the B cells analysed, clonal dominance or factors from the culture system, which need to be addressed in future studies. Proteomic