Particle density fluctuations

Event-by-event fluctuations in the multiplicities of charged particles and photons at SPS energies are discussed. Fluctuations are studied by controlling the centrality of the reaction and rapidity acceptance of the detectors. Results are also presented on the event-by-event study of correlations between the multiplicity of charged particles and photons to search for DCC-like signals.Comment: Talk presented at Quark Matter 2002, Nantes, Franc

Suppression of High-p_T Neutral Pion Production in Central Pb+Pb Collisions at sqrt{s_NN} = 17.3 GeV Relative to p+C and p+Pb Collisions

Neutral pion transverse momentum spectra were measured in p+C and p+Pb collisions at sqrt{s_NN} = 17.4 GeV at mid-rapidity 2.3 < eta_lab < 3.0 over the range 0.7< p_T < 3.5 GeV/c. The spectra are compared to pi0 spectra measured in Pb+Pb collisions at sqrt{s_NN} = 17.3 GeV in the same experiment. For a wide range of Pb+Pb centralities (N_part < 300) the yield of pi0's with p_T > 2 GeV/c is larger than or consistent with the p+C or p+Pb yields scaled with the number of nucleon-nucleon collisions (N_coll), while for central Pb+Pb collisions with N_part > 350 the pi0 yield is suppressed.Comment: 5 pages, 4 figure

Pion Freeze-Out Time in Pb+Pb Collisions at 158 A GeV/c Studied via pi-/pi+ and K-/K+ Ratios

The effect of the final state Coulomb interaction on particles produced in Pb+Pb collisions at 158 A GeV/c has been investigated in the WA98 experiment through the study of the pi-/pi+ and K-/K+ ratios measured as a function of transverse mass. While the ratio for kaons shows no significant transverse mass dependence, the pi-/pi+ ratio is enhanced at small transverse mass values with an enhancement that increases with centrality. A silicon pad detector located near the target is used to estimate the contribution of hyperon decays to the pi-/pi+ ratio. The comparison of results with predictions of the RQMD model in which the Coulomb interaction has been incorporated allows to place constraints on the time of the pion freeze-out.Comment: 9 pages, 12 figure

Crystallographic reconstruction study of the effects of finish rolling temperature on the variant selection during bainite transformation in C-Mn high-strength steels

The effect of finish rolling temperature (FRT) on the austenite- () to-bainite () phase transformation is quantitatively investigated in high-strength C-Mn steels. In particular, the present study aims to clarify the respective contributions of the conditioning during the hot rolling and the variant selection (VS) during the phase transformation to the inherited texture. To this end, an alternative crystallographic reconstruction procedure, which can be directly applied to experimental electron backscatter diffraction (EBSD) mappings, is developed by combining the best features of the existing models: the orientation relationship (OR) refinement, the local pixel-by-pixel analysis and the nuclei identification and spreading strategy. The applicability of this method is demonstrated on both quenching and partitioning (Q&P) and as-quenched lath-martensite steels. The results obtained on the C-Mn steels confirm that the sample finish rolled at the lowest temperature (829{\deg}C) exhibits the sharpest transformation texture. It is shown that this sharp texture is exclusively due to a strong VS from parent brass {110}, S {213} and Goss {110} grains, whereas the VS from the copper {112} grains is insensitive to the FRT. In addition, a statistical VS analysis proves that the habit planes of the selected variants do not systematically correspond to the predicted active slip planes using the Taylor model. In contrast, a correlation between the Bain group to which the selected variants belong and the FRT is clearly revealed, regardless of the parent orientation. These results are discussed in terms of polygranular accommodation mechanisms, especially in view of the observed development in the hot-rolled samples of high-angle grain boundaries with misorientation axes between and

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Implementing core outcomes in kidney disease: report of the Standardized Outcomes in Nephrology (SONG) implementation workshop

There are an estimated 14,000 randomized trials published in chronic kidney disease. The most frequently reported outcomes are biochemical endpoints, rather than clinical and patient-reported outcomes including cardiovascular disease, mortality, and quality of life. While many trials have focused on optimizing kidney health, the heterogeneity and uncertain relevance of outcomes reported across trials may limit their policy and practice impact. The international Standardized Outcomes in Nephrology (SONG) Initiative was formed to identify core outcomes that are critically important to patients and health professionals, to be reported consistently across trials. We convened a SONG Implementation Workshop to discuss the implementation of core outcomes. Eighty-two patients/caregivers and health professionals participated in plenary and breakout discussions. In this report, we summarize the findings of the workshop in two main themes: socializing the concept of core outcomes, and demonstrating feasibility and usability. We outline implementation strategies and pathways to be established through partnership with stakeholders, which may bolster acceptance and reporting of core outcomes in trials, and encourage their use by end-users such as guideline producers and policymakers to help improve patient-important outcomes

Época da indução e evocação floral em Citrus sinensis (L.) Osbeck cv. Pêra Rio The flower induction and evocation period in Citrus sinensis (L.) Osbeck cv. Pêra Rio

A produção do estímulo floral (indução) e emissão das primeiras sépalas, na gema floralmente determinada (evocação floral) em Citrus sinensis (L.) Osbeck cv. Pêra Rio pôde ser acompanhada pelas variações anatômicas nos meristemas apicais e axilares. Com objetivo de determinar a época na qual ocorre a indução e evocação floral, cortes longitudinais de gemas apicais e axilares, corados com pironina Y-methylgreen foram efetuados em períodos regulares de maio a agosto. Através das mudanças no formato da gema, principalmente diâmetro, que aumentou com a indução, foi possível determinar a época do ano na qual gemas vegetativas são induzidas a florescerem. Foram detectadas variações nos diâmetros das gemas no período de início da morfogênese floral (meados até o final de julho). A medição do diâmetro das gemas mostra-se um procedimento eficiente para acompanhar os fenômenos decorrentes da indução, evocação e morfogênese florais. Gemas vegetativas apresentam diâmetro médio de 100µm, com túnica composta por três camadas, de formato cônico, recobrindo o corpo, ao passo que a reprodutiva é mais achatada, após a iniciação do primeiro primórdio de sépala, exibindo diâmetro médio de 200µm. Coloração com pironina Y-methylgreen proporciona a captação do fenômeno da evocação floral, pela detecção de regiões mais concentradas em RNA, nas zonas periféricas das gemas; alteração bioquímica esta que precede a emissão das sépalas.<br>The research aims to determine the time in which the inflorescence induction and evocation occurs. The production of inflorescence stimulus (induction) and emission of first sepals in a bud determined as a flower bud (floral evocation) in Citrus sinensis (L.) Osbeck cv. Pêra Rio could be observed through the anatomic variations of the apical and lateral meristems. Longitudinal sections, stained with pironina Y-methylgreen were done in regular periods from May to August. The time of the year in which the vegetative buds are induced to blossom was determined through the bud shape changes, chiefly considering the diameter, which has increased with the induction. Bud diameter variations were detected on the second half of July, the period of floral morphogenesis incipience. The measurement of the bud diameter is an efficient procedure to follow up the phenomena originated from the floral induction, evocation and morphogenesis. Vegetative buds bring out an average diameter of 100µm with a three-layer tunic in a conic shape, recovering its body. The reproductive bud, in turn, is flatter, after the initiation of the first sepal primordium, showing an average diameter of 200µm. The pironina Y-methylgreen stain provides the observation of the floral evocation phenomenon, through the detection of regions with a higher RNA level, in the bud external areas. This biochemical alteration precedes the sepal emission