The 2dF Galaxy Redshift Survey: the power spectrum and the matter content of the Universe

The 2dF Galaxy Redshift Survey has now measured in excess of 160000 galaxy redshifts. This paper presents the power spectrum of the galaxy distribution, calculated using a direct Fourier transform based technique. We argue that, within the k-space region 0.02<~k<~0.15hMpc-1, the shape of this spectrum should be close to that of the linear density perturbations convolved with the window function of the survey. This window function and its convolving effect on the power spectrum estimate are analysed in detail. By convolving model spectra, we are able to fit the power-spectrum data and provide a measure of the matter content of the Universe. Our results show that models containing baryon oscillations are mildly preferred over featureless power spectra. Analysis of the data yields 68 per cent confidence limits on the total matter density times the Hubble parameter Ωmh=0.20+/-0.03, and the baryon fraction Ωb/Ωm=0.15+/-0.07, assuming scale-invariant primordial fluctuations

The 2dF galaxy redshift survey: near-infrared galaxy luminosity functions

We combine the Two Micron All Sky Survey (2MASS) Extended Source Catalogue and the 2dF Galaxy Redshift Survey to produce an infrared selected galaxy catalogue with 17173 measured redshifts. We use this extensive data set to estimate the galaxy luminosity functions in the J- and KS-bands. The luminosity functions are fairly well fitted by Schechter functions with parameters MJ*-5logh=-22.36+/-0.02, αJ=-0.93+/-0.04, ΦJ*=0.0104+/-0.0016h3Mpc-3 in the J-band and MKS*-5logh=-23.44+/-0.03, αKS=-0.96+/-0.05, ΦKS*=0.0108+/-0.0016h3Mpc-3 in the KS-band (2MASS Kron magnitudes). These parameters are derived assuming a cosmological model with Ω0=0.3 and Λ0=0.7. With data sets of this size, systematic rather than random errors are the dominant source of uncertainty in the determination of the luminosity function. We carry out a careful investigation of possible systematic effects in our data. The surface brightness distribution of the sample shows no evidence that significant numbers of low surface brightness or compact galaxies are missed by the survey. We estimate the present-day distributions of bJ-KS and J-KS colours as a function of the absolute magnitude and use models of the galaxy stellar populations, constrained by the observed optical and infrared colours, to infer the galaxy stellar mass function. Integrated over all galaxy masses, this yields a total mass fraction in stars (in units of the critical mass density) of Ωstarsh=(1.6+/-0.24)×10-3 for a Kennicutt initial mass function (IMF) and Ωstarsh=(2.9+/-0.43)×10-3 for a Salpeter IMF. These values are consistent with those inferred from observational estimates of the total star formation history of the Universe provided that dust extinction corrections are modest

The 2dF Galaxy Redshift Survey: a targeted study of catalogued clusters of galaxies

We have carried out a study of known clusters within the 2dF Galaxy Redshift Survey (2dFGRS) observed areas and have identified 431 Abell, 173APM and 343 EDCC clusters. Precise redshifts, velocity dispersions and new centroids have been measured for the majority of these objects, and this information is used to study the completeness of these catalogues, the level of contamination from foreground and background structures along the cluster's line of sight, the space density of the clusters as a function of redshift, and their velocity dispersion distributions. We find that the Abell and EDCC catalogues are contaminated at the level of about 10 per cent, whereas the APM catalogue suffers only 5 per cent contamination. If we use the original catalogue centroids, the level of contamination rises to approximately 15 per cent for the Abell and EDCC catalogues, showing that the presence of foreground and background groups may alter the richness of clusters in these catalogues. There is a deficiency of clusters at z~0.05 that may correspond to a large underdensity in the Southern hemisphere. From the cumulative distribution of velocity dispersions for these clusters, we derive a space density of σ>1000kms-1 clusters of 3.6×10-6h3Mpc-3. This result is used to constrain models for structure formation; our data favour low-density cosmologies, subject to the usual assumptions concerning the shape and normalization of the power spectrum

Loss of coral reef growth capacity to track future increases in sea level

Sea-level rise (SLR) is predicted to elevate water depths above coral reefs and to increase coastal wave exposure as ecological degradation limits vertical reef growth, but projections lack data on interactions between local rates of reef growth and sea level rise. Here we calculate the vertical growth potential of more than 200 tropical western Atlantic and Indian Ocean reefs, and compare these against recent and projected rates of SLR under different Representative Concentration Pathway (RCP) scenarios. Although many reefs retain accretion rates close to recent SLR trends, few will have the capacity to track SLR projections under RCP4.5 scenarios without sustained ecological recovery, and under RCP8.5 scenarios most reefs are predicted to experience mean water depth increases of more than 0.5 m by 2100. Coral cover strongly predicts reef capacity to track SLR, but threshold cover levels that will be necessary to prevent submergence are well above those observed on most reefs. Urgent action is thus needed to mitigate climate, sea-level and future ecological changes in order to limit the magnitude of future reef submergence

Polioencefalomalacia em bovinos nos estados de Mato Grosso do Sul e São Paulo Polioencephalomalacia in cattle in the states of Mato Grosso do Sul and São Paulo

Trinta focos de polioencefalomalacia (PEM) foram diagnosticados no período de agosto de 1993 a outubro de 1997. Vinte e nove focos ocorreram no estado de Mato Grosso do Sul (MS) e um no estado de São Paulo (SP). Foram afetados bovinos de 4 a 84 meses de idade. A morbidade dos rebanhos afetados variou de 0,02% a 14,28% e a letalidade de 42,5% a 100%. A doença não apresentou uma sazonalidade e ocorreu em vários municípios do MS. Em todos os focos estudados os animais afetados eram criados em regimes de criação extensiva, com exceção de um foco. Os sinais clínicos observados foram exclusivamente nervosos e a evolução dos casos variou de 12 horas a 4 dias. A maioria dos animais tratados com tiamina e dexametasona recuperou-se. Histologicamente, as lesões consistiam de necrose laminar do córtex cerebral. Adicionalmente em 2 casos observaram-se hemorragias submeningeanas e corticais, e em 9 casos presença de infiltrado de eosinófilos. A dosagem de sódio no líquor apresentou-se elevada em um caso. A etiologia da PEM não está esclarecida, porém em alguns casos a intoxicação por cloreto de sódio/privação de água pode estar envolvida na etiologia da enfermidade. A PEM representa 4,78% dos casos de enfermidades de bovinos diagnosticadas no Laboratório de Anatomia Patológica da UFMS. Com bases nos resultados, verifica-se a importância da enfermidade no diagnóstico diferencial de outras doenças com quadro clínico neurológico no MS, principalmente a raiva, a meningoencefalite por herpesvírus bovino tipo 5 (HVB-5) e o botulismo.<br>Thirty outbreaks of polioencephalomalacia (PEM) were diagnosed from August 1993 to October 1997. Twenty nine occurred in the state of Mato Grosso do Sul and one in São Paulo. The disease affected cattle from 4 months to 7 years of age. Morbidity rates ranged from 0.02% to 14.28% and case fatalities from 42.5 % to 100%. The disease was not seasonal. All outbreaks occurred in cattle grazing Brachiaria spp, except one affecting feedlot cattle. Only neurologic signs were observed, and the course of the disease varied from 12 hours to 4 days in untreated cattle. Most animals treated with thiamine and dexamethazone recovered. Moderate cerebral edema was observed at necropsy. Cell changes were characterized by laminar necrosis and gitter cells. In two cases moderate cortical and submeningeal hemorrhages were observed. Nine cases had perivascular and submeningeal infiltrations by eosinophils. Sodium ion concentration of the cerebrospinal fluid was elevated in one case. The cause of PEM in the region was not determined, but the results suggest that in some cases sodium chloride intoxication/water deprivation could play a role in the etiology of the disease. PEM represents 4.78% of cattle disease diagnosed at the Pathology Laboratory of the Federal University of Mato Grosso do Sul

Carcinoma de células escamosas perineal em cabras no Pará Perineal squamous cell carcinoma in goats in the State of Pará, Brazil

Descreve-se a ocorrência de carcinoma de células escamosas (CCE) bem diferenciado em caprinos de duas propriedades no Estado do Pará. Foram observadas a prevalência, a correlação com a pigmentação da região perineal e as características macro e microscópica das lesões. As lesões consistiram em tumores no períneo, com grau de desenvolvimento, diâmetro e forma variados. Em uma propriedade no município de Viseu, dos 347 caprinos, 20 apresentaram CCE (5,8%). A neoplasia só foi observada em animais com a região perineal despigmentada. Em outra propriedade, no município de Garrafão do Norte, descreve-se a ocorrência de três casos em um rebanho de 400 caprinos (0,75%). A elevada ocorrência deste tumor deve-se, provavelmente, à despigmentação do períneo e à cauda curta e elevada das cabras, que expõe a região perineal à alta incidência de radiação ultravioleta naquela região.<br>Squamous cell carcinoma in goats of two farms in the State of Pará is described. Prevalence, correlation with the pigmentation of the perineal area and macro and microscopic characteristics of the lesions were studied. The tumors on the perineum were of varied development degrees, diameters and forms. On one farm, in the county of Viseu, from a total of 347 goats, 20 presented the neoplasia (5.8%). On the second farm, in the county of Garrafão do Norte, three cases of squamous cell carcinoma in a herd of 400 goats (0.75%) were observed. The tumor was only observed in animals in which the perineal area was despigmented. The high incidence of this tumor appears to be due to lack of pigmentation at the períneo and the high and short tail of the goats, that exposes the area to intense ultraviolet radiation in the tropics