Direct evidence of histopathological impacts of wastewater discharge on resident Antarctic fish (Trematomus bernacchii) at Davis Station, East Antarctica.

During the 2009/2010 summer, a comprehensive environmental impact assessment (EIA) of the wastewater discharge at Davis Station, East Antarctica was completed. As part of this, histological alteration of gill and liver tissue in Antarctic Rock-cod (Trematomus bernacchii) from four sites along a spatial gradient from the wastewater outfall were assessed. All fish within 800 m of the outfall exhibited significant histological changes in both tissues. Common pathologies observed in fish closest to the outfall include proliferation of epithelial cells with associated secondary lamellar fusion in the gills and multifocal granulomata with inflammation and necrosis as well as cysts in the liver. Fish from sites >800 m from the outfall also exhibited alterations but to a lesser degree, with prevalence and severity decreasing with increasing distance from the outfall. This study highlights the value of histopathological investigations as part of EIAs and provides the first evidence of sub-lethal alteration associated with wastewater discharge in East Antarctica.

Tracking spatial distribution of human-derived wastewater from Davis Station, East Antarctica, using δ15N and δ13C stable isotopes.

Stable isotope ratios, δ15N and δ13C were effectively used to determine the geographical dispersion of human derived sewage from Davis Station, East Antarctica, using Antarctic rock cod (Trematomus bernacchii). Fish within 0-4km downstream of the outfall exhibited higher δ15N and δ13C values relative to reference sites. Nitrogen in particular showed a stepped decrease in δ15N with increasing distance from the discharge point by 1-2‰. Stable isotopes were better able to detect the extent of wastewater contamination than other techniques including faecal coliform and sterol measures. Uptake and assimilation of δ15N and δ13C up to 4km from the outfall adds to growing evidence indicating the current level of wastewater treatment at Davis Station is not sufficient to avoid impact to the surrounding environment. Isotopic assimilation in T. bernacchii is a viable biomarker for investigation of initial sewage exposure and longer term monitoring in the future.

Application of a quantitative histological health index for Antarctic rock cod (Trematomus bernacchii) from Davis Station, East Antarctica

A quantitative Histological Health Index (HHI) was applied to Antarctic rock cod (Trematomus bernacchii) using gill, liver, spleen, kidney and gonad to assess the impact of wastewater effluent from Davis Station, East Antarctica. A total of 120 fish were collected from 6 sites in the Prydz Bay region of East Antarctica at varying distances from the wastewater outfall. The HHI revealed a greater severity of alteration in fish at the wastewater outfall, which decreased stepwise with distance. Gill and liver displayed the greatest severity of alteration in fish occurring in close proximity to the wastewater outfall, showing severe and pronounced alteration respectively. Findings of the HHI add to a growing weight of evidence indicating that the current level of wastewater treatment at Davis Station is insufficient to prevent impact to the surrounding environment. The HHI for T. bernacchii developed in this study is recommended as a useful risk assessment tool for assessing in situ, sub-lethal impacts from station-derived contamination in coastal regions throughout Antarctica.

Alex E. Davis, Graduate of the New York Trade School

Alexander Davis, Jr., a graduate of the Carpentry program of the New York Trade School in 1955 is shown working. Original caption reads, "Carpenter Contractor, Alex E. Davis Builder, Easton, Pa. Alexander Davis, Jr. - Carpentry 1955. The remodeling of old and building of new houses etc., offers many opportunities for success. Mr. Davis is shown hanging a new door on a building." Black and white photograph with caption glued to reverse.

Abordagem histórica e perspectivas atuais do ensino superior agrícola no Brasil : uma investigação na UFRGS e na UC Davis

Este estudo analisa o Ensino Superior Agrícola Brasileiro – ESAB, como “campo” (Bourdieu, 1983a), diante do cenário do mundo cambiante em que vivemos, com os seguintes objetivos: (i) resgatar parte da história, destacando dois momentos de inflexão vividos pelo ESAB: o primeiro a partir da década de 1960, quando, dentro do projeto urbano-industrialista, foram lançadas as bases do conhecimento e das estruturas acadêmicas (ainda hegemônicos) para a “modernização da agricultura”. O segundo na virada do Século XX, quando existe uma multiplicidade de propostas e não há mais um modelo a ser copiado; (ii) sugerir alguns dos caminhos possíveis e suas implicações para as instituições do ESAB, que pretendam encontrar novo sentido social no seu trabalho; (iii) analisar a influência das Universidades Norte-americanas no ESAB, tendo em vista sua importância no período de 60 e como essa influência se manifesta no segundo momento. Um “college” norte-americano (College of Agricultural and Environmental Science da University of California – Davis) e uma faculdade brasileira (Faculdade de Agronomia da UFRGS) foram escolhidos, como centros de formação e de pesquisa importantes e com participação destacada nos intercâmbios bilaterais. Essas instituições servem como testemunhas exemplares da dinâmica geral. Em ambas foram realizadas investigações e foram ouvidos atores destacados (professores-pesquisadores), através de questionários e entrevistas ao vivo Nas duas universidades os professores mostraram-se conscientes sobre as mudanças em curso, mas na UFRGS parece que o debate está menos desenvolvido. Diante das tendências que se apresentam, a Agricultura Sustentável e a Biotecnologia foram eleitas como pólos aglutinadores de diferentes projetos em disputa no início do Milênio. O estudo conclui que ou as escolas de agronomia se modificam ou não se justificam e também que, as mudanças podem ou não se vincular à busca de uma ruptura paradigmática (Santos, 1997). Conclui ainda, que seria importante cada instituição explicitar sua proposta, mesmo que esta seja de convivência entre os diferentes projetos. Finalmente opina que, Agricultura Sustentável parece ser estrategicamente mais interessante; tendo em vista ser mais adequada à realidade social e ambiental do Brasil.

Efeito da densidade de ninfas de Aphis gossypii Glover, 1877 (Hemiptera, Aphididae) no consumo alimentar e aspectos biológicos de Orius insidiosus (Say, 1832) (Hemiptera, Anthocoridae)

Orius insidiosus (SAY, 1832) is an important predator for biological pest control programs. The objective of this work was to evaluate the functional response, predation capacity and reproductive aspects of O. insidiosus when predating 1, 5, 10, 15, and 20 third/fourth instar nymphs of Aphis gossypii. The tests were conducted under laboratory conditions. Females of the predator were individually maintained in Petri dishes with a cotton leaf at each one of the aphid densities. The average rate of predation was of 0.93 [plus or minus] 0.13, 3.58 [plus or minus] 0.80, 7.31 [plus or minus] 1.45, 7.40 [plus or minus] 1.16, and 10.54 [plus or minus] 1.84 at the densities of 1, 5, 10, 15, and 20 aphids, respectively. The results showed an attack rate of 0.10 h-1 and 1.82 h of manipulation time. The predator spent 3.10 to 4.08 h feeding on leaf cotton glands; this behavior was not directly influenced by the prey density. The proportion of egg laying per female grew up to the density of 10 nymphs whereas the number of eggs per laying increased with the number of available preys.

Efeito de cultivares de algodoeiro sobre a biologia e capacidade predatória de Orius Insidiosus (say, 1832) (hemiptera: anthocoridae) predando Aphis Gossypii Glover, 1877 (Hemiptera: Aphididae)

The objective of this research was to determine the survival, reproduction and predaceous capacity of Orius insidiosus on cotton aphid Aphis gossypii. Cotton plants of Antares, CNPA7H and Acala 90 cultivars (respectively, without tricome, medium tricome density and high tricome density) were individualized and infested with 15 third/fourth instar nymphs of A. gossypii, and then first-instar nymphs of O. insidiosus were released on the plants. The evaluations were made daily, quantifying survival and nymphal development; the number of cotton aphids A. gossypii per day and total; the number of eggs and the population of the predator (number of insects by female); and the conversion efficiency of A. gossypii predaceous. The nymphal development did not differ according to the cotton cultivars. The Antares cultivar favored a higher daily predation rate for the 1st, 2nd and 4th instars and adults of O. insidiosus. The number of eggs and nymphs was smaller when O. insidiosus females were confined on the Acala 90 cultivar. According to the predation rate of O. insidiosus, the efficiency of alimentary conversion was determined for the Antares, CNPA7H and Acala 90 cultivars, being respectively, 4.28, 3.00 and 2.75 cotton aphid predation for each egg of the predator.

Tabelas de vida de Orius insidiosus (Say, 1832) (Hemiptera: Anthocoridae) predando Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) em diferentes cultivares de algodoeiro

The life table parameters were studied for Orius insidiosus on the three cotton plant cultivars Antares, CNPA7H and Acala 90 (respectively, without tricome, medium tricome density and high tricome density). This study showed that the type of cultivar can strongly influence the life-table parameters. The intrinsic rate (rm) was 0.088 (on Antares), 0.081 (CNPA7H) and 0.079 (on Acala 90), which was expected as these differences were also observed for development time, survival, fecundity and longevity on the cultivars. The reproductive rate (Ro) was 18.53 on the Antares cultivar, but showed less difference for CNPA7H (12.26) and Acala 90 (12.95). The development time was 33.9, 30.62 and 32.13 days for Antares, CNPA7H and Acala 90, respectively. The age-specific survival was similar until the 12th day. Maximum survival was 60 days on the Antares cultivar. Females usually began to oviposit after 16 days on the Antares cultivar and the after 19 days day on CNPA7H and Acala 90.

Reproductive indices in natural nests of giant Amazon river turtles Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae) in the Environmental Protection Area Meanders of the Araguaia river

Realizou-se a contagem dos ovos não eclodidos, dos filhotes vivos e mortos de Podocnemis expansa oriundos de 327 ninhos naturais, localizados nas praias da Área de Proteção Ambiental (APA) - Meandros do Rio Araguaia, onde se determinou a porcentagem de eclosão dos ovos (94,63%); não eclosão (5,37%); sobrevivência (94,24%) e mortalidade dos filhotes (5,76%), e a média de filhotes mortos durante os 15 dias no berçário (0,97%). A média do total de filhotes por ninho foi determinada pela soma do número de filhotes vivos e mortos divididos pelo total de ninhos, enquanto que a média do total de ovos por ninho foi determinada pela soma do número de filhotes vivos, mortos e ovos não eclodidos divididos pelo total de ninhos. Com isso, obtiveram-se os valores médios do número de filhotes vivos (88,98 ± 23,94); mortos (0,37 ± 0,93); ovos não eclodidos (5,07 ± 9,57), e total de ovos (94,42 ± 21,30). A eficiência reprodutiva da população selvagem de P. expansa pode ser afetada por muitos fatores ambientais, como temperatura, umidade e precipitação. Além disso, fatores influenciados pelo homem, como a presença de produtos químicos na água e a possibilidade de doenças infecciosas, também têm impacto significativo. Os dados dos índices reprodutivos obtidos neste estudo são indispensáveis para futuras investigações de anomalias de incubação.