Measurement of (anti)deuteron and (anti)proton production in DIS at HERA

The first observation of (anti)deuterons in deep inelastic scattering at HERA has been made with the ZEUS detector at a centre-of-mass energy of 300--318 GeV using an integrated luminosity of 120 pb-1. The measurement was performed in the central rapidity region for transverse momentum per unit of mass in the range 0.3<p_T/M<0.7. The particle rates have been extracted and interpreted in terms of the coalescence model. The (anti)deuteron production yield is smaller than the (anti)proton yield by approximately three orders of magnitude, consistent with the world measurements.Comment: 26 pages, 9 figures, 5 tables, submitted to Nucl. Phys.

The Caravan Rolls On

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68409/2/10.1177_107554707900100103.pd

Experimental characterization of the Xe 5p photoionization by angle- and spin-resolved photoelectron spectroscopy

Heckenkamp C, Schäfers F, Schönhense G, Heinzmann U. Experimental characterization of the Xe 5p photoionization by angle- and spin-resolved photoelectron spectroscopy. Zeitschrift für Physik D: Atoms, Molecules and Clusters. 1986;2(4):257-274.Spin- and angle-resolved photoelectron spectroscopy with elliptically polarized radiation has been used to fully characterize the dynamics of photoelectron emission from free Xe atoms in the 5p-autoionization and continuum region. An advantageous reaction geometry and its experimental realization at the storage ring BESSY are discussed. The three independent experimental parameters which characterize the angular dependence of the photoelectron spin-polarization vector are reported for the wavelength range from 100nm to 40 nm. The results are compared with theoretical predictions based on RRPA-, RPAE- and semiempirical MQDT-calculations. The combination of existing data for the differential photoionization cross section with the spinpolarization parameters is used to completely decouple the photoionization channels: The transition matrix elements and their relative phases are determined separately for every single dissociation channel. The results are discussed in the context of the MQDT. Correlation effects and the influence of spin-orbit interaction on the continuum states most clearly show up when the Dill-Fano angular-momentum-transfer formalism is applied

Frequency of the CCRdelta32 allele in Brazilians: a study in colorectal cancer and in HTLV-I infection

The identification of a 32-bp deletion in the cc-chemokine receptor-5 gene (CCR5delta32 allele) that renders homozygous individuals highly resistant to HIV infection has prompted worldwide investigations of the frequency of the CCR5delta32 allele in regional populations. It is important to ascertain if CCR5delta32 is a factor to be considered in the overall epidemiology of HIV in individual populations. With this in mind we determined the CCR5delta32 allele frequency in a large sample (907 individuals) of the southeastern Brazilian urban population, stratified as follows: 322 healthy unrelated individuals, 354 unselected colorectal cancer patients, and 229 blood donors. The three groups displayed essentially identical allelic frequencies of CCR5delta32 and pairwise comparisons did not show significant differences. Thus, our results can be pooled to provide a reliable estimate of the CCR5delta32 allele frequency in the southeastern Brazil of 0.053 ± 0.005. The blood donors comprised 50 HTLV-I serologically negative individuals, 115 non-symptomatic individuals HTLV-I positive by ELISA but with indeterminate Western blot results, 49 healthy blood donors HTLV-I positive both at ELISA and Western blot and 15 patients with clinical spinal cord disease (HAM). A suggestive trend was observed, with the CCR5delta32 frequencies decreasing progressively in these four categories. However, when we applied Fischer's exact test no significant differences emerged. We believe that further studies in larger cohorts should be performed to ascertain whether the CCR5delta32 allele influences the chance of becoming infected or developing clinical symptoms of HTLV-I infection.<br>A observação de que indivíduos homozigotos para uma deleção de 32 pares de base no gene que codifica para o receptor 5 de cc-quimiocinas apresentam um menor risco de contrair a infecção por HIV-1 levou à investigação da freqüência deste polimorfismo em várias populações mundiais. É importante investigar se o CCR5delta32 é um fator a ser considerado na epidemiologia do HIV em populações individuais. Com estes pressupostos em mente nós estabelecemos a freqüência do CCR5delta32 em uma grande amostra (907 indivíduos não-relacionados) da população urbana do sudeste brasileiro, estratificada da seguinte maneira: 322 indivíduos sadios, 354 pacientes com câncer colorretal e 229 doadores de sangue. Os três grupos apresentaram essencialmente a mesma freqüência alélica de CCR5delta32 e a comparação par-a-par não revelou diferenças significativas. Assim, os nossos resultados podem ser agrupados para fornecer uma estimativa confiável de 0,053 ± 0,005 da freqüência alélica de CCR5delta32. Os doadores de sangue compreendiam 50 indivíduos soronegativos para HTLV-I, 115 indivíduos assintomáticos por ELISA mas com resultados indeterminados em Western blot, 49 indivíduos soropositivos para HTLV-I mas assintomáticos e 15 indivíduos soropositivos para HTLV-I sintomáticos com mielopatia. Foi observado um sugestivo gradiente decrescente da freqüência alélica de CCR5delta32 nestas categorias. Entretanto, quando aplicamos o teste exato de Fisher, não emergiram diferenças significativas. Para uma melhor avaliação da influência do alelo CCR5delta32 na probabilidade de infectar-se com HTLV-I ou de desenvolver doença clínica serão necessários estudos com um maior número de doadores de sangue

What do the australian black summer fires signify for the global fire crisis?

The 2019–20 Australian fire season was heralded as emblematic of the catastrophic harm wrought by climate change. Similarly extreme wildfire seasons have occurred across the globe in recent years. Here, we apply a pyrogeographic lens to the recent Australian fires to examine the range of causes, impacts and responses. We find that the extensive area burnt was due to extreme climatic circumstances. However, antecedent hazard reduction burns (prescribed burns with the aim of reducing fuel loads) were effective in reducing fire severity and house loss, but their effectiveness declined under extreme weather conditions. Impacts were disproportionately borne by socially disadvantaged regional communities. Urban populations were also impacted through prolonged smoke exposure. The fires produced large carbon emissions, burnt fire-sensitive ecosystems and exposed large areas to the risk of biodiversity decline by being too frequently burnt in the future. We argue that the rate of change in fire risk delivered by climate change is outstripping the capacity of our ecological and social systems to adapt. A multi-lateral approach is required to mitigate future fire risk, with an emphasis on reducing the vulnerability of people through a reinvigoration of community-level capacity for targeted actions to complement mainstream fire management capacity