22 research outputs found
Collective non-Abelian instabilities in a melting Color Glass Condensate
We present first results for 3+1-D simulations of SU(2) Yang-Mills equations
for matter expanding into the vacuum after a heavy ion collision. Violations of
boost invariance cause a Weibel instability leading soft modes to grow with
proper time as , where is a
scale arising from the saturation of gluons in the nuclear wavefunction. The
scale for the growth rate is set by a plasmon mass, defined as
, generated dynamically
in the collision. We compare the numerical ratio to the
corresponding value predicted by the Hard Thermal Loop formalism for
anisotropic plasmas.Comment: 4 pages, 4 figures, revtex4; v2: typos corrected, discussion on
growth rate in expanding system added, accepted for publication in PR
Physics Revealed at Intermediate p_T
A review is given on the subject of hadron production at intermediate
in heavy-ion collisions. The underlying dynamical processes are inferred from
interpreting the data in the framework of recombination. Ridge formation with
or without triggers is found to play an important role in nearly all
observables in that region. Correlation data would be hard to interpret
without taking ridges into account. The semi-hard partons that create the
ridges may even be able to drive elliptic flow without fast thermalization.Comment: 8 pages, plenary talk given at Quark Matter 2008, Jaipur, Indi
A Technique For Developing Strategic Differentiation For Small Architectural Firms
Since the crash in 2007, the number of small architectural firms has risen dramatically as both recently graduated and recently laid off architects decide to go out on their own. In such a crowded market firms will need to find some way to distinguish themselves from their many competitors. Arguing from the Resource Based Strategy theory the authors assert that to be successful architectural firms must build and promote competences which are both scarce and in demand in order to compete successfully. This should especially be the case in a ‘buyers’ market’. Architect starting their own firms must provide something more than standard package of architectural services will not be enough to permit new firms to gain clients. A series of case studies was used to compare this theoretical proposition with the experience of recently established architectural firms (+-5 years). The case studies gathered firm histories including the original goals of the principle architect(s), their entrance strategies andmarketing approaches, their client list and portfolios of acquired and completed projects. This permitted a comparison to be made between the firm profile the architects originally desired to establish, and the profiles eventually realized. In particular, the perceived selling points which the principle architects believed would provide them with the ability to acquire projects with the services they eventually were able to sell. The case studies supported the assertion that a clear differentiation strategy is one means of successfully launching a firm and gaining a client base
Genetic markers of resistance to pyrimethamine and sulfonamides in Plasmodium falciparum parasites compared with the resistance patterns in isolates of Escherichia coli from the same children in Guinea-Bissau.
The antifolate drugs sulphadoxine and pyrimethamine are used for treatment of chloroquine-resistant Plasmodium falciparum in Africa. Resistance to pyrimethamine has been associated with point mutations in the dhfr-gene and resistance to sulphadoxine with mutations in the dhps-gene. There is concern that the use of the antifolates trimethoprim and sulphamethoxazole for treatment of other infectious diseases will result in the selection of malaria parasites with mutations in these genes. In Guinea-Bissau, where sulfonamide and trimethoprim-containing drugs have been used extensively, we decided to assess the prevalence of mutations in the dhfr-and dhps-gene in P. falciparum isolated from children suffering from acute malaria and to assess the resistance patterns to trimethoprim/sulphamethoxazole in Escherichia coli isolated from the same patients. A thick film and a blood sample for polymerase chain reaction (PCR) were obtained from 100 children attending the Bandim Health Centre in Bissau with symptoms compatible with malaria. Furthermore, a stool sample was collected from the same children and cultured for E. coli. Of the cultured E. coli, 67% were resistant both to sulfonamides and trimethoprim, 4% to sulfonamides alone, 3% to trimethoprim alone while 26% were fully sensitive to both drugs. PCR was successfully performed in 97 blood samples. Of these, 41% had triple mutations at the dhfr-gene (at codons 51, 59 and 108), and 15% had triple mutations plus mutation at codon 437 in the dhps-gene. Only 45% harboured the wild-type dhfr-gene. Thus both bacterial resistance and mutations in the parasitic genes were common, but not linked in the individual child. As sulphadoxine-pyrimethamine has only been used as a second line treatment for chloroquine resistant malaria in Guinea-Bissau for a few years, it is worrying to find a high prevalence of mutations in the parasitic genes coding for resistance to these drugs. Therefore, restricting the use of sulphadoxine-pyrimethamine for the treatment of chloroquine resistant malaria might not be sufficient to prevent the development of resistance in the parasites as long as antifolate drugs are used extensively