A risk assessment approach to manage inundation of Elseya albagula nests in impounded waters: a win-win situation?

A risk assessment process was used to trial the impact of potential new operating rules on the frequency of nest inundation for the White-throated snapping turtle, Elseya albagula, in the impounded waters of the Burnett River, Queensland, Australia. The proposed operating rules would increase the barrage storage level during the turtle nesting season (May-July) and then would be allowed to reduce to a lower level for incubation for the rest of the year. These proposed operating rules reduce rates of nest inundation by altering water levels in the Ben Anderson Barrage impoundment of the Burnett River. The rules operate throughout the turtle reproductive period and concomitantly improve stability of littoral habitat and fishway operation. Additionally, the proposed rules are expected to have positive socio-economic benefits within the region. While regulated water resources will inherently have a number of negative environmental implications, these potential new operating rules have the capacity to benefit the environment while managing resources in a more sustainable manner. The operating rules have now been enacted in subordinate legislation and require the operator to maintain water levels to minimize turtle nest inundation.

A Coordinated Effort to Manage Soybean Rust in North America: A Success Story in Soybean Disease Monitoring.

Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss. Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops. A recent example of a successful disease-monitoring program for an economically important crop is the soybean rust (SBR) monitoring effort within North America. SBR, caused by the fungus Phakopsora pachyrhizi, was first identified in the continental United States in November 2004. SBR causes moderate to severe yield losses globally. The fungus produces foliar lesions on soybean (Glycine max) and other legume hosts. P. pachyrhizi diverts nutrients from the host to its own growth and reproduction. The lesions also reduce photosynthetic area. Uredinia rupture the host epidermis and diminish stomatal regulation of transpiration to cause tissue desiccation and premature defoliation. Severe soybean yield losses can occur if plants defoliate during the mid-reproductive growth stages. The rapid response to the threat of SBR in North America resulted in an unprecedented amount of information dissemination and the development of a real-time, publicly available monitoring and prediction system known as the Soybean Rust-Pest Information Platform for Extension and Education (SBR-PIPE). The objectives of this article are (i) to highlight the successful response effort to SBR in North America, and (ii) to introduce researchers to the quantity and type of data generated by SBR-PIPE. Data from this system may now be used to answer questions about the biology, ecology, and epidemiology of an important pathogen and disease of soybean.

Interval training in men at risk for insulin resistance.

We compared 3 months of eucaloric (12 kcal/kg/wk) steady state aerobic training (AER) to interval training (INT) in men at risk for insulin resistance. Primary outcomes included oral glucose tolerance testing (OGTT) and HOMA-IR 24 h and 72 h after each participants last exercise session. Secondary outcomes were VO2max, anthropometry, and metabolic syndrome expressed as a summed z-score (zMS). We also performed a sub-analysis for participants entering the trial above and below the HOMA-IR study median. Mean (95% CI) AER ( - 12.81 mg/dl; - 24.7, - 1.0) and INT ( - 14.26 mg/dl; - 24.9, - 3.6) significantly improved 24 h OGTT. HOMA-IR did not improve for AER, but did for INT 24 h and 72 h post-exercise. VO2max improved similarly for both groups. Changes in body mass for INT ( - 2.29 kg; - 3.51, - 1.14), AER, ( - 1.32 kg; - 2.62, 0.58)] and percent body fat [INT, - 0.83%; - 1.62, - 0.03), AER ( - 0.17%; - 1.07, 0.06)] were only significant for INT. When examined as a full cohort, zMS improved for both groups. Upon HOMA-IR stratification, only high HOMA-IR AER showed significant improvements, while both low and high INT HOMA-IR participants demonstrated significant reductions (P<0.05). Eucaloric AER and INT appear to affect fasting glucose, OGTT and VO2max similarly, while INT may have a greater impact on HOMA-IR and zMS.

High- and low-level pressure support during walking in people with severe kyphoscoliosis.

To determine whether the level of pressure support (PS) provided during exercise influences endurance time in people with severe kyphoscoliosis, a double-blind randomised crossover study was performed. We hypothesised that high-level PS would be required to enhance endurance time in this population with high impedance to inflation. 13 participants with severe kyphoscoliosis performed four endurance treadmill tests in random order: unassisted; with sham PS; low-level PS of 10 cmH(2)O (PS 10); and high-level PS of 20 cmH(2)O (PS 20). Participants and assessors were blinded to the level of PS delivered during exercise. Endurance time was greater with PS 20 (median (interquartile range) 217 (168-424) s) compared with unassisted exercise (139 (111-189) s), sham PS (103 (88-155) s) and PS 10 (159 (131-206) s). In addition, isotime respiratory rate was decreased by 8 breaths x min(-1) (95% CI -11- -5 breaths x min(-1)) and isotime oxygen saturation increased by 4% (95% CI 1-7%) with PS 20 compared with unassisted exercise. People with severe kyphoscoliosis require high-level PS during walking to improve exercise performance. Investigation of high-level PS as an adjunct to exercise training or to assist in the performance of daily activities is warranted.

Effect of Brown Rust on Yield of Sugarcane in Louisiana.

Brown rust, caused by Puccinia melanocephala, can cause severe epidemics in susceptible sugarcane cultivars during spring and early summer in Louisiana. The effect of the disease on yield was evaluated in field experiments conducted during three growing seasons. A mixture of three fungicides-azoxystrobin, propiconazole, and tebuconazole-applied biweekly during the spring epidemic period kept brown rust severity low (<5%), and plants protected by fungicide applications throughout the epidemic provided an estimate of attainable yield for comparison with plants naturally infected with rust. A combined analysis over three seasons estimated brown rust caused reductions of 16 and 14% in cane tonnage and total amount of sucrose produced, respectively, in cv. LCP 85-384. The greatest reduction in total sucrose yield of 22% resulted from the epidemic of longest duration, and stalk weight was negatively correlated with rust severity. Comparisons of the yields obtained from plots in which brown rust was controlled early versus late in the epidemic suggested that the impact of the disease is greatest from the middle to late epidemic period when stem elongation has begun.

Viability of Phakopsora pachyrhizi Urediniospores Under Simulated Southern Louisiana Winter Temperature Conditions.

Soybean rust, caused by Phakopsora pachyrhizi, originally occurred in Asia. It has now spread to South America and the continental United States. This disease has the potential to cause severe economic losses to U.S. soybean growers, especially in the south, where the environmental conditions are more favorable to P. pachyrhizi survival during winter. In the present study, the effect of simulated southern Louisiana winter temperature conditions (12°C, 14-h days and 1°C, 10-h nights with 75% relative humidity) on soybean rust urediniospore viability was examined. It was found that urediniospore viability declined rapidly from 72 to 40% after 1 day and then decreased gradually to 17% after 7 days and 11% after 60 days. Spores stored under southern Louisiana winter conditions for 60 days still produced pustules on inoculated leaves. In comparison, the viability of spores stored at room temperature decreased gradually and reached 0% at the end of 60 days. Winter temperature treatment not only reduced spore viability but also decreased germ tube growth. In addition, soybean rust spores recovered from overwintered dry kudzu leaves were also found viable. This study indicates that soybean rust spores could survive southern Louisiana winter conditions and initiate a new cycle of infection in the next growing season.

First Report of Soybean Rust Caused by Phakopsora pachyrhizi in the Continental United States.

Asian soybean rust, caused by Phakopsora pachyrhizi Sydow, has been known to occur in the eastern hemisphere for nearly a century. More recently, it was reported from Hawaii in 1994, eastern and southern Africa from 1996-1998, Nigeria in 2001, and Brazil and Paraguay in 2002. Aerobiological models suggested that urediniospores of the pathogen would be disseminated on wind currents to the continental United States in association with tropical storms if the disease became established north of the equator during hurricane season (U.S. Soybean Rust Detection and Aerobiological Modeling online publication at www.aphis.usda.gov/ppq/ ep/soybean_rust/ ). Since soybean rust was observed at approximately 5°N latitude in South America before several hurricanes impacted the continental United States in September 2004, it seems likely that the introduction was associated with at least one of these tropical storms, especially hurricane Ivan. Symptoms of the disease were first observed on soybean (Glycine max (L.) Merr.) in the continental United States on November 6, 2004 in a field near Baton Rouge, LA. Typical pustules and urediniospores on infected leaves were readily apparent when viewed with a dissecting microscope. Urediniospores were obovoid to broadly ellipsoidal, hyaline to pale yellowish brown with a minutely echinulate thin wall, and measured 18 to 37 × 15 to 24 µm. Paraphyses were cylindric to clavate and slightly thickened at the apex, colorless to pale yellowish brown, and 25-50 × 6-14 µm in size. This morphology is typical of Phakopsora pachyrhizi and P. meibomiae, a less aggressive, western hemisphere species (2). DNA was extracted from leaves containing sori using the Qiagen DNeasy Plant Mini kit. P. pachyrhizi was detected using a real-time polymerase chain reaction (PCR) protocol (1) that differentiates between P. pachyrhizi and P. meibomiae performed in a Cepheid thermocycler with appropriate positive and negative controls. The PCR master mix was modified to include OmniMix beads (Cepheid). The field diagnosis of P. pachyrhizi was confirmed officially by the USDA/APHIS on November 10, 2004, and this was followed on November 11, 2004 by a wide-ranging survey of soybean and kudzu (Pueraria sp.) in soybean production areas in southern and central Louisiana. Collections from this survey also were assayed as described above, and six soybean specimens from five sites were confirmed positive. The disease was not found on kudzu samples. To our knowledge, this is the first report of P. pachyrhizi in the continental United States. Voucher specimens have been placed in the USDA National Fungus Collection. References: (1) R. D. Frederick et al. Phytopathology 92:217, 2002. (2) Y. Ono et al. Mycol. Res. 96:825, 1992.