Patterns of lipid storage and mobilisation in the female green sea turtle (Chelonia mydas)

Reproductive data from southern Queensland indicate that vitellogenesis in female Chelonia mydas takes approximately 8 months and is followed by a migration to a breeding area. At Heron Island, females lay multiple clutches over approximately 3 months. To investigate how females mobilise and store lipid during the breeding season we collected plasma, yolk, and fat tissue samples from females at a variety of stages during the nesting season. In breeding females, concentrations of plasma triglyceride increased seasonally. They reached peak concentrations during vitellogenesis and courtship, remained high throughout the nesting season, and then declined to a nadir after the last clutch. Plasma protein concentration increased throughout the breeding season, peaking following the last clutch for the season. Yolk lipids were highest during courtship and were similar throughout the nesting season, suggesting that uptake of lipid by ovarian follicles is completed prior to the beginning of the nesting season. Plasma triglyceride decreases in females with prolonged periods of unsuccessful nesting, and total lipid levels in adipose tissue and follicle yolks were significantly lower in atretic females. It appears that: (1) endogenous energy reserves can be reduced by stochastic environmental events (such as those reducing nesting success), and (2) a metabolic shift signalling the end of the nesting season is characterised by a drop in plasma triglycerides and slight increase in total plasma protein.

Interactions among endocrinology, seasonal reproductive cycles and the nesting biology of the female green sea turtle

We collected data on plasma levels of testosterone+5a-dihydrotestosterone (T+DHT) and corticosterone (CORT) from adult female green sea turtles (Chelonia mydas) from southern Queensland during distinct stages of their reproductive cycle. Those females capable of breeding in a given year had elevated plasma steroid levels (T+DHT 0.91 +/- 0.08; CORT 1.05 +/- 0.29 ng/ml), associated with follicular development, until courtship began in October. At the beginning of the nesting season in November plasma levels of 2 CORT were related to when the female first nested (r(2) = 0.06; F = 10.45; P = 0.01). However, they were not correlated with the number of clutches a female laid in that season (F = 3.65; P = 0.08). We repeatedly sampled 23 turtles over the nesting season and profiled changes in steroids immediately following oviposition of each clutch. Levels of T+DHT (range 0.41-0.58 ng/ml) and CORT (range 2.13-2.81 ng/ml) were similar through the early stages of the nesting season and inter-nesting period, and declined to near basal levels (T+DHT 0.37 +/- 0.03 and CORT 1.85 +/- ng/ml) following the last clutch for the season. Steroid hormone levels were also low (T+DHT 0.38 +/- 0.16; CORT 0.46 +/- 0.21 ng/ml) in four independent post-breeding (atretic) females; samples for these females were taken at a time when body condition was presumably at the lowest for the season. Subtle changes in the nesting environment, such as variation in nesting habitat or the time of night that nesting occurred, were associated with a small and slow CORT increase. We suggest CORT is increased in nesting females to assist in lipid transfer to prepare the ovarian follicles and/or the reproductive organs for ovulation.

In vivo and in vitro toxicities of pithraj and neem against rice green leafhopper (Nephotettix cincticeps Uhler)

Seed extracts of Aphanamixis polystachya Wall et Parker (pithraj) and Azadirachta indica A. Juss (neem) were evaluated for their in vivo and in vitro toxicity to Nephotettix cincticeps Uhler (rice green leafhopper). Crude extracts from both plants showed toxicity to leafhopper. Among them, the methanol extract of pithraj (MCX) was most toxic and showed 95% mortality effects at 72 h after treatment (HAT), followed by neem (74%). When LD50's were compared, it was found that the neem extract possessed the highest toxicity (LD50 16.59 μg/insect) at 72 HAT. Both the pithraj (MCX) and neem extracts showed their enzyme inhibition effectiveness against rice green leafhopper. The highest inhibition rate (IR) was caused by neem (60%) at the concentration of 2.0 mg/ml, followed by MCX (47%). The lowest IR50 value (0.97 mg/ml) was observed in neem at 30 min.

Malaria vectors on Buka and Bougainville islands, Papua New Guinea

Anophelines were sampled from 82 locations oil Buka and Bougainville islands in Papua New Guinea by larval collections, carbon dioxide-baited Mosquito traps, and human biting catches. Anopheles farauti s.s. was collected in larval Surveys but infrequently in mosquito traps on both islands; on Buka Island this species was readily collected in human biting catches. Anopheles faraunti 2 was commonly collected in larval surveys on both islands however. it was not collected in either mosquito traps or human biting catches. Anopheles punctulatus was found only on Buka Island, where it was commonly collected as larvae, but rarely in human biting catches and mosquito traps. Anopheles lungae was collected Lis larvae from only I site on Bougainville. Anopheles farauti s.s. led consistently throughout the night (1900-0600 h): small peaks at midnight and dawn were not statistically significant. Of 1,156 An. farauti s.s. specimens examined by enzyme-linked immunosorbent assay for malaria sporozoites. 20 were found to be positive: 12 were positive for Plasmodium falciparum and 8 were positive for P. vivax (247 variant = 5: 210 variant = 3). Anopheles farauti s.s. seems to be the major malaria vector on these islands, whereas An. punctulatus may play a minor role on Buka Island. Anophele farauti 2 is unlikely to be involved in malaria transmission on Buka or Bougainville islands.

Strange bedfellows: Green Hill Fort, archaeology and tourism

Green Hill Fort, Thursday Islalld was constructed between 1891-1893 to defend the Australian colonies against a feared Russian invasion. It retained an operational role until the 1920.'1 and played a minor role in World /t'ar 2. From 1954 to 1993 the site, but not the facilities, was used as a weather station. More recently it has been home ofthe Ton-es Strait Historical Society and Museum Association museum. It is a major attraction during the tourist season and an important local icon. For archaeologists it has sign~ficance as a relatively intact nineteenth-century military installation. Two 'Centenary of Federation' grants have proVided the impetus to undertake conservation and presentation works involving various task -spec~fic, archaeological activities. At the management level archaeologists play the lead role in the project. The project has demonstrated the value oJarchaeology and tourism joining forces. The danger ofa 'theme park 'presentation has been avoided. Technical accuracy and careful site planning has ensured a high degree ofaccuracy is retained. Provided these qualities can be assured then, it is argued, there is an opportunity for archaeology to be a majOl; long-term beneficiary. But to achieve that, the discipline must move from being entrenched in its academic mould and become Jar more receptive to the broader needs ofthe twentyfirst century.

Genetic structure of Mycosphaerella fijiensis populations from Australia, Papua New Guinea and the Pacific Islands

Single-copy restriction fragment length polymorphism (RFLP) markers were used to determine the genetic structure of Mycosphaerella fijiensis, the cause of black leaf streak (black Sigatoka) disease of banana and plantain, in the Torres Strait, Papua New Guinea (PNG), and the Pacific Islands. A moderate level of genetic variation was observed in all populations with genotypic diversity values of 60-78% of the theoretical maximum, and gene diversity (H) values between 0.269 and 0.336. All populations were at gametic equilibrium, and with the high level of genotypic diversity observed this indicated that sexual reproduction has a major role in the genetic structure of the M. fijiensis populations examined. Population differentiation was tested on several hierarchical scales. No evidence of population differentiation was observed between sites on Mer Island. A moderate level of population differentiation was observed within the Torres Strait, between Badu and Mer Islands (F-ST = 0.097). On a regional scale, the greatest differentiation was found between the populations of the Torres Strait and the Pacific. Populations from these regions were more closely related to the PNG population than to each other, suggesting they were founded in separate events from the same population.

Substituição dos parâmetros do modelo de Green-Ampt-Mein-Larson para estimativa da infiltração em alguns solos do Brasil

A partir de uma análise detalhada do processo de infiltração de água no solo, foram propostas alternativas para adequação dos parâmetros de entrada do modelo de Green-Ampt-Mein-Larson (GAML), na tentativa de melhorar a eficiência da estimativa da infiltração em alguns solos brasileiros. As adequações consistiram em substituir a condutividade hidráulica do solo saturado (K0) pela taxa de infiltração estável (Tie) e o teor de água do solo saturado (qs) pelo teor de água na zona de transmissão (qw), além de estabelecer uma equação para estimativa do potencial matricial na frente de umedecimento (yf) com base nos parâmetros do modelo de curva de retenção de água de Brooks & Corey. Avaliou-se o desempenho do conjunto de adequações propostas (GAML-t) para estimativa da infiltração de água em três solos: Latossolo Vermelho-Amarelo, Latossolo Vermelho e Argissolo Vermelho. O desempenho do GAML-t foi comparado com o obtido pelo GAML aplicado em sua forma original e adequado segundo cinco diferentes formas, evidenciando-se que o primeiro obteve melhor desempenho nos três solos estudados.

Broccoli yield in response to top-dressing fertilization with green manure and biofertilizer

The objective of this work was to evaluate the productive performance of broccoli under different top-dressing organic fertilizations. The experiment was conducted under protected cultivation, in a completely randomized design with four replications, with two plants per experimental unit. Broccoli seedlings were produced in a commercial substrate in styrofoam trays. The seedlings were transplanted to plastic pots containing 10.0 L of substrate made up of subsoil and organic compost at the ratio of 3:1 (v/v), respectively, which is equivalent to about 20.0 t ha-1 of organic compost at planting. After seedling establishment, the top-dressing fertilization treatments were applied: gliricidia biomass associated or not with liquid biofertilizer of cattle manure to the soil and bokashi. Two control treatments were established: one with mineral fertilization recommended for the crop and the other without top-dressing fertilization. The broccoli production was evaluated (commercial standard). Plants that received mineral fertilizer were more productive, however, they were not significantly different (p>0.05), by Dunnet test, from the plants fertilized with 2.5 t ha-1 gliricidiabiomass (dry mass) associated with liquid biofertilizer (2.0 L m-2) applied to soil. Top-dressing fertilizations with only gliricidia, at 2.5 and 5.0 t ha-1 of biomass (dry mass), resulted in no significant increase in production of broccoli inflorescence. The use of bokashi in addition to gliricidia biomass and liquid biofertilizer reduced the efficiency of the fertilization compared with plants that received only gliricidia and liquid biofertilizer.

Influence of nitrogen fertilization and green manure on the economic feasibility of no-tilled wheat in the Cerrado

The search for higher profitability in wheat crop with cost reduction technologies that may promote sustainability is an important matter in Brazilian agriculture. This study evaluated the profitability of no-tilled wheat, reducing nitrogen topdressing doses with the cultivation of green manure before the wheat crop. The experiment was carried out in Selvíria (MS), Brazil, in 2009/10. The experiment was arranged in a randomized block design with 36 treatments in splitplots and four replicates. The plots were formed by six types of green manure: Cajanus cajan L. BRS Mandarin, Crotalaria juncea L., Pennisetum americanum L. BRS 1501, fallow area and mixed cropping of Pennisetum americanum L. + Cajanus cajan L. and Pennisetum americanum L. + crotalaria which provided straw for no-tilled wheat in the winter, following the rice crop in the summer. The subplots were formed by six levels of topdressing nitrogen (0, 25, 50, 75, 100 and 125 kg N ha-1) using urea as a nitrogen source. The wheat grown after green manure in the previous winter crop, with no nitrogen topdressing and a rate of 25 kg ha-1 N, had more frequently production costs above the gross income. Wheat production cost after the mixed cropping Pennisetum americanum L. + Cajanus cajan L. and Pennisetum americanum L. + Crotalaria juncea L. from the previous winter crop, combined with nitrogen rates of 50 and 75 kg N ha-1, provided better profitability compared with the other green manures evaluated.

Phytomass production and nutrient accumulation by green manure species

Green manuring is recognized as a viable alternative to improve nutrient cycling in soils. The aim of this study was to evaluate the phytomass production and nutrient accumulation in shoots of the summer green manures jack bean [Canavalia ensiformis (L.) DC.], dwarf pigeon pea (Cajanus cajanvar var. Flavus DC.), dwarf mucuna [Mucuna deeringiana (Bort) Merr] and sunn hemp (Crotalaria juncea L.), under nitrogen fertilization and/or inoculation with N-fixing bacteria. A split plot design was arranged with the four Fabaceae species as main plots and nitrogen fertilization (with and without) and inoculation with diazotrophic bacteria (with and without) as the subplots, in a 2² factorial. The experiment was arranged as a randomized complete block design with four replications. In the conditions of this trial, the sunn hemp had the highest production of shoot phytomass (12.4 Mg ha-1) and nutrient accumulation, while the dwarf mucuna had the lowest production of shoot phytomass (3.9 Mg ha-1) and nutrient accumulation. The results showed no effect of nitrogen fertilization or inoculation with N-fixing bacteria on the production of shoot phytomass and nutrient accumulation, except for inoculation without nitrogen fertilization, resulting in greater P accumulation (p <0.05) in the sunn hemp and greater Zn and Mn accumulation in the dwarf mucuna. These findings indicate that N fertilization or inoculation with N2-fixing bacteria for Fabaceae are low efficiency practices in the edaphoclimatic conditions of this study.