Leaky doors: private captivity as a prominent source of bird introductions in Australia

The international pet trade is a major source of emerging invasive vertebrate species. We used online resources as a novel source of information for accidental bird escapes, and we investigated the factors that influence the frequency and distribution of bird escapes at a continental scale. We collected information on over 5,000 pet birds reported to be missing on animal websites during the last 15 years in Australia. We investigated whether variables linked to pet ownership successfully predicted bird escapes, and we assessed the potential distribution of these escapes. Most of the reported birds were parrots (> 90%), thus, we analysed factors associated with the frequency of parrot escapes. We found that bird escapes in Australia are much more frequent than previously acknowledged. Bird escapes were reported more frequently within, or around, large Australian capital cities. Socio-economic factors, such as the average personal income level of the community, and the level of human modification to the environment were the best predictors of bird escapes. Cheaper parrot species, Australian natives, and parrot species regarded as peaceful or playful were the most frequently reported escapees. Accidental introductions have been overlooked as an important source of animal incursions. Information on bird escapes is available online in many higher income countries and, in Australia, this is particularly apparent for parrot species. We believe that online resources may provide useful tools for passive surveillance for non-native pet species. Online surveillance will be particularly relevant for species that are highly reported, such as parrots, and species that are either valuable or highly commensal.Miquel Vall-llosera, Phillip Casse

Growth and phenological development patterns differ between seedling and regrowth lucerne crops (Medicago sativa L.)

This study compared physiological responses of fully irrigated seedling and regrowth lucerne crops (Medicago sativa L.) grown under similar environmental field conditions. Measurements occurred for 2-4 years after sowing on 24 October, 15 November, 05 December and 27 December 2000 at Lincoln, Canterbury, New Zealand. Irrespective of the date of sowing, on average lucerne accumulated less shoot dry matter (DM) in the seedling year (11±0.44tha -1 ) than during the regrowth year (18±0.76tha -1 ). Slower shoot-growth rates in seedlings were explained by less intercepted light and reduced efficiency in conversion of light to biomass. Specifically, seedlings had a longer phyllochron (47±2.3°Cd leaf -1 ) and slower leaf area expansion rate (0.009m 2 m -2 °Cd -1 ) than regrowth crops (35±1.8°Cd leaf -1 and 0.016m -2 m -2 °Cd, respectively). There were no differences in canopy architecture with a common extinction coefficient of 0.93. The radiation use efficiency (RUE) for shoot production (RUE shoot ) was 1.2±0.16g DM MJ -1 of intercepted photosynthetically active radiation (PAR i ) in seedlings and 1.9±0.24g DM MJ -1 PAR i in regrowth crops. Reproductive development was slower in seedling than regrowth crops due to an apparent juvenile period ranging from 240 to 530°Cd in seedlings. For both seedling and regrowth phases, the thermal time accumulation to reach 50% buds visible (Tt 0-bv ) and 50% open flowers (Tt 0-fl ) increased as photoperiod shortened in autumn. The minimum Tt 0-bv , or the thermal-time duration of the basic vegetative period (Tt BVP ), was estimated at 270±48°Cd at photoperiods > 14h for regrowth crops. The theoretical threshold below which reproductive development is projected to cease, or the base photoperiod (Pp base ), was estimated at a common 6.9h for seedling and regrowth crops. The transition from buds visible to open flowers (Tt bv-fl ) was mainly controlled by air temperature and ranged from 161°Cd for seedlings to 274°Cd for regrowth crops. These results can be used as guidelines to develop differential management strategies for seedling and r egrowth crops and improve the parameterization of lucerne simulation models. © 2011 Elsevier B.V

Denitrification in vadose zone material amended with dissolved organic matter from topsoil and subsoil

Limited information is available on the potential of subsoil and underlying alluvial gravels (vadose zone) to denitrify leached nitrate, though it is recognized that C availability is an important constraint. In this laboratory study, we used samples (<4 mm fraction) from subsoil (0.4–0.85 m depth) and alluvial gravel layers (1.2–4.8 m) derived from a site in Canterbury, New Zealand, to quantify denitrification potential and examine the denitrification response to inputs of dissolved organic C (DOC). As C sources, we used DOC extracted in either cold (20 °C) or hot (80 °C) water from topsoil and subsoil (assumed to represent C substrates likely to be transported into the subsoil in drainage). Measurements of potential denitrification enzyme activity (DEA, via samples amended with glucose and nitrate-N) showed the alluvial gravel samples had denitrification capability although rates were low (<5 μg N₂O–N kg⁻¹ h⁻¹) compared with those reported for topsoils. The effect of the soil-derived DOC, at addition rates 16–215 mg kg⁻¹, on denitrification was determined in a 7-d anaerobic incubation using acetylene to block reduction of N₂O to N₂. There was a lag of 24–36 h, during which N₂O production was low, followed by a period of rapid increase (36–96 h), and a final phase (120–168 h) in which N₂O concentrations remained relatively stable. During the rapid phase, the N₂O production rate was very high (up to 440–500 μg N kg⁻¹ h⁻¹ at the highest DOC addition rate) and exceeded that measured in the 8-h DEA assay (a measure of indigenous denitrifier enzymes). The post-96 h decline in N₂O production rate was attributed to depletion of available C. The temporal pattern of CO₂–C production was similar to that of N₂O, though the lag period was shorter (12–24 h). The ratio of N₂O–N to CO₂–C increased with time; the maximum was circa 0.3:1 at the highest addition rate of hot water extractable DOC. Our results suggest that, with input of DOC substrate, alluvial gravel materials could generate enough enzyme during a 1–2 day anaerobic period to denitrify significant quantities of nitrate. However, in situ denitrification in alluvial gravels may be low because of biophysical limitations such as low C inputs of bioavailable C and anaerobicity mostly confined to localized zones or lenses

Association of progressive outer retinal necrosis and varicella zoster encephalitis in a patient with AIDS.

BACKGROUND: A patient with AIDS who developed the clinical picture of bilateral progressive outer retinal necrosis (PORN) in combination with varicella zoster encephalitis is described. The picture developed more than 2 years after an episode of ophthalmic zoster infection, and following intermittent exposure to oral acyclovir because of recurrent episodes of cutaneous herpes simplex infection. METHODS: Aqueous humour, obtained by paracentesis of the anterior chamber, was analysed using immunofluorescence and polymerase chain reaction (PCR). Postmortem analysis of eye and brain tissue was performed by using conventional techniques and in situ hybridisation. RESULTS: While conventional techniques all failed to detect a causative agent, analysis of the aqueous humour using PCR, and histological examination of necropsy specimens from eyes and brain using in situ hybridisation were conclusive for the diagnosis varicella zoster virus (VZV) infection. CONCLUSION: This case documents the presumed association of PORN and VZV encephalitis in a severely immunocompromised AIDS patient

Quantity and biodegradability of dissolved organic matter released from sequentially leached soils, as influenced by the extent of soil drying prior to rewetting

Soil rewetting can induce a flush of organic matter mineralisation, but the factors underpinning this mineralisation response are poorly understood. We investigated the effects of antecedent soil water content, before rewetting, on the quantity, quality and biodegradability of dissolved organic matter present in the leachate pore volumes from a soil under two different management histories: arable and grassland. Soils were collected at field capacity (FC) and dried to give four soil gravimetric water contents ( Ɵg ): 22% (not dried, left at FC), 15%, 8% and <2% (air dry, AD). Soils were repacked to the same bulk density (1.1 g cm⁻³ ) and each core was sequentially leached, with four pore volumes collected. The total amount of dissolved organic carbon (DOC) leached increased (P < 0.001) only in the soils that had been air-dried before rewetting (3.8 and 5.3 mg g⁻¹ soil C, for arable and grassland respectively), while among the other g treatments differences were relatively small (1.6-2.4 mg g⁻¹ soil C). The pre-rewetting Ɵg treatment affected the DOC content of the pore volume leached (P < 0.001): in the grassland soil, the DOC of the AD treatment was consistently twice as high as the other treatments, but this trend was not as consistent in the arable soil. For all Ɵg treatments and both soils, specific ultraviolet absorbance at 254 nm increased as leaching progressed. Biodegradability, expressed as cumulative CO₂ produced per unit of DOC in leachates, was significantly lower in the first pore volume of all treatments in the grassland soil and increased with sequential leaching. In the arable soil, differences were small or insignificant across the pore volumes leached, but were large and inconsistent across the Ɵg treatments. These findings improve our understanding of how antecedent soil water content affects the quantity and quality of dissolved organic matter released when soils are rewetted, and the potential for soil carbon losses

Fomivirsen - a phosphorothioate oligonucleotide for the treatment of CMV retinitis

Fomivirsen is a 21-nucleotide phosphorothioate oligonucleotide which, when injected into a human eye, is capable of inhibiting CMV retinitis. Its mode of action is consistent with an antisense mechanism. Prior to human trials, fomivirsen was tested in a number of in vitro cell lines and was found to inhibit CMV replication in a dose-dependent manner with a mean 50% inhibitory concentration between 0.03 and 0.2 microM. Intravitreal drug clearance studies have revealed first-order kinetics with a half-life in the rabbit of 62 hours. In a clinical trial of patients with newly diagnosed CMV retinitis receiving 165 mg per injection, time to progression was interpolated to 71 days with 44% of the patients remaining on treatment for over one year. In patients who failed other anti-CMV treatments, the interpolated time to progression was 91 days when receiving 330 mg per injection. No systemic absorption of the drug could be detected. Reported adverse events have been for the most part mild to moderate in intensity and either resolved spontaneously or were treatable with topical medications. Locally administered fomivirsen effectively inhibits CMV retinitis using a mode of action which is complementary to existing DNA polymerase inhibitor

Quantifying contaminant losses to water from pastoral landuses in New Zealand I. Development of a spatial framework for assessing losses at a farm scale

Assessing the effectiveness of mitigation measures for reducing contaminant losses to water from pastoral farming systems is a challenging task. Two important factors that contribute to this challenge are (i) the considerable spatial variability in landscape vulnerabilities to contaminant loss and (ii) differing land use pressures created by contrasting land management practices that are employed on farms. An approach is described that benchmarks nitrogen (N), phosphorus (P) and sediment discharges for representative dairy and sheep-beef farming types (hereafter referred to as ‘typologies’) that differ according to inherent landscape vulnerability features or land use pressures created by some key management practices. Landscape vulnerabilities can be defined as the soil, topography and climate factors that are known to influence the inherent risk of contaminant transport to water, whereas land use pressures reflect the diverse set of farm inputs and feed, stock and soil management practices that determine contaminant sources. The analysis was constructed using land use pressure information for the year 2015 contained within Dairybase records held by DairyNZ and farm class surveys reported by Beef + Lamb NZ. Published information sources and expert opinion from rural professionals were also used to define land use pressures for typologies in 1995

Optic neuritis heralding varicella zoster virus retinitis in a patient with acquired immunodeficiency syndrome

We report on a 29-year-old severely compromised acquired immunodeficiency syndrome patient who developed retrobulbar optic neuritis 5 weeks after an episode of cutaneous herpes zoster infection. During the optic neuritis, varicella zoster virus could be demonstrated in the cerebrospinal fluid. The neuritis responded well to treatment with foscarnet, but, 3 weeks into therapy, varicella zoster retinitis developed. Additional treatment with intravenous acyclovir stopped progression of the retinitis and resulted in healing of the retinal lesions. This case suggests that retrobulbar optic neuritis can be regarded as a prodrome of imminent acute retinal necrosis. Early recognition and prompt therapy with combined antivirals may prevent the development of this devastating ocular complication of varicella zoster infectio

Effects of protease inhibitors on the course of CMV retinitis in relation to CD4+ lymphocyte responses in HIV+ patients

AIM—To gain insight into the course of CMV retinitis (CMVR) in AIDS patients receiving protease inhibitors (PI), and to evaluate whether certain patterns of CD4 response are indicative of the clinical outcome and the risk of recurrence.
METHODS—15 consecutive AIDS patients receiving maintenance therapy for CMVR were included in a prospective observational cohort study at the university hospital between July and October 1996. Patients were evaluated for signs of CMVR activity and intraocular inflammation. CMVR recurrence was defined as the primary clinical endpoint. Follow up was performed until July 1997. No patient was lost to follow up. Clinical outcome was related to CD4+ lymphocyte counts, which were monitored every 6 weeks. Highly active antiretroviral treatment regimen including PI was started at study entry.
RESULTS—All recurrences (n=7) were in patients who failed to have a sustained increase in CD4 counts, whereas CMVR remained inactive during a follow up of 42-52 weeks in those who were able permanently to restore their CD4 values to 100×10(6)/l or more (n=5). The remaining three patients died after 12,( )16, and 50 weeks, respectively, without recurrences. All relapses of CMVR were seen after 6-16 weeks, and at CD4 counts well below 100×10(6)/l.
CONCLUSIONS—The beneficial effects of PI treatment correlate with the pattern of CD4 response. Sustained increases in CD4 counts achieved in the first 16 weeks of treatment are associated with a prolonged period of CMVR quiescence. Poor initial response is associated with a high risk of CMVR recurrence.

 Keywords: AIDS; cytomegalovirus retinitis; HAART; protease inhibitor