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Nectaroscordum (Lindl.) Gren. & Godr. (Alliaceae) is a small subgenus of the genus Allium consisting of only two species, Allium siculum (Ucria) Lindl. and Allium tripedale (Trautv.) Grossh. Both are rare ornamental bulbous plants used in gardening. The former is native to Asia Minor, southern France, and Sicily (hence the trivial name Sicilian honey garlic), where it grows in damp shady woods. It is still sometimes referred to by the synonymous names Allium nectaroscordum, Nectaroscordum siculum Ucria, A. dioscorides auct., or A. meliophilum Juz. The second member of the subgenus, A. tripedale (syn. N. tripedale Trautv. or N. persicum (Bornm.) Bornm.), is indigenous to Armenia, Iran, and Iraq. Both members of the Nectaroscordum subgenus, A. siculum and A. tripedale, are very closely related to other plants of the genus Allium L. Due to their close morphological similarities, the relationship between these two groups has long been embroiled in taxonomic controversy. At present, classification of Nectaroscordum as a subgenus in the Allium genus is generally accepted. The chromosome basic number of x ) 9, special and unique characteristics of most flower parts, and other morphological peculiarities of Nectaroscordum species were the main arguments in support of separating this oligotypic group at a generic level. 1-3 A. siculum attracted our attention because of its odor, which is notably different from that of common alliaceous plants. This paper describes our investigation of the amino acid odor precursors present in this plant and their primary breakdown products.

More than 250 coliform and noncoliform bacteria, isolated by standard membrane filtration methods from rural, untreated groundwater supplies, were examined for resistance to 16 antibiotics. All of the noncoliforms and 87% of the coliforms were resistant to at least one antibiotic, with resistance most commonly directed toward novobiocin, cephalothin, and ampicillin. The frequency of multiple antibiotic resistance (MAR) within each species was also determined. Approximately 60% of the coliforms were MAR, including 14, 64, and 94% of Escherichia coli, Citrobacter freundii, and Enterobacter cloacae isolates, respectively. In comparison, MAR was demonstrated by more than 95% of the noncoliforms and included isolates of Acinetobacter calcoaceticus, Aeromonas hydrophila, and Serratia marcescens. Ampicillin-resistant environmental isolates were assayed for ability to transfer resistance to ampicillin-sensitive strains of E. coli and Salmonella typhimurium. Environmental E. coli isolates were capable of in vitro transfer to both recipients in a nutrient-rich environment (trypticase soy broth) at frequencies ranging from 1.1 × 10−5 to 1.0 × 10−4. Isolates of C. freundii and Klebsiella pneumoniae exhibited resistance transfer to the E. coli recipient under similar conditions at reduced rates. None of the environmental isolates demonstrated transfer of ampicillin resistance when placed in an environment containing filter-sterilized well water. The presence of antibiotic resistant bacteria, and particularly MAR bacteria, in rural groundwater supplies used as drinking water sources may have important public health implications.

To model screwworm fly (Diptera: Calliphoridae) population dynamics, it is necessary to quantify the relationship between soil moisture and screwworm fly numbers. Climatic data from one case study of Chrysomya bezziana (Villeneuve) and five case studies of Cochliomyia hominivorax (Coquerel) from tropical and subtropical areas were statistically analysed to determine the effect of soil moisture (corrected for temperature) on screwworm fly incidence. Significant relationships occurred in three of the six cases; in two cases the relationship was humped, and in the other linear. Both prolonged dry conditions and soil saturation cause reduced screwworm fly emergence whereas intermediate soil moisture is adequate for pupal development and adult emergence. the relationship previously used in the CLIMEX package was found to be biased because it did not adequately penalise saturated soil conditions. an improved function was estimated to correct for this bias.

BACKGROUND. The Bethesda 2001 (B2001) classification system raised the threshold for reporting atypical squamous cells. The category of Atypical Squamous Cells of Undetermined Significance (ASCUS)-favor reactive has been eliminated with a recommendation for cytologists to judiciously downgrade those Papanicolaou (Pap) tests that would formerly have been in this category to Negative for Intraepithelial Lesion or Malignancy (NILM). The effect of this change on sensitivity and specificity of the Pap test is not yet known. METHODS. A total of 535 consecutive SurePath Pap tests interpreted as ASCUS during a period from March 1 through December 31, 2001, with follow-up polymerase chain reaction(PCR)-based human papilloma virus (HPV) testing, were independently reviewed by 3 pathologists and 1 cytotechnologist who reinterpreted these tests according to Bethesda 2001 criteria. Follow-up HPV and biopsy results were compiled for a 5-year period. RESULTS. By consensus of the 4 observers, 169 (32%) of the ASCUS cases were downgraded to NILM. These cases showed a lower rate of underlying high-risk HPV infection (11% vs 30%) and cervical intraepithelial neoplasia of grades 2 to 3 (CIN 2/3) (5% vs 10%) on follow-up than those tests that were reinterpreted as ASCUS or higher. Nine women with follow-up CIN 2/3 would have had the Pap test interpreted as NILM instead of ASCUS under Bethesda 2001 (20% of all CIN 2/3 found). Individual reviewers downgraded 29% to 42% Pap tests to NILM including those of 5 to 10 women with follow-up CIN 2/3. CONCLUSIONS. The ASCUS threshold established by B2001 prevents a sizeable subset of women from having follow-up for ASC. However, as a consequence, a few women with CIN 2/3 are downgraded to NILM. The cost savings thus achieved must be weighed against the lost opportunities to detect CIN 2/3. Cancer (Cancer Cytopathol) 2008. © 2008 American Cancer Society.

Vaccination represents the most effective form of protection against influenza infection. While neutralizing antibodies are typically measured as a correlate of vaccine-induced protective immunity against influenza, nonneutralizing antibodies may contribute to protection or amelioration of disease. The goal of this study was to dissect the individual contributions of the immunoglobulin G1 (IgG1) and IgG2a antibody isotypes to vaccine-induced immunity against influenza virus. To accomplish this, we utilized an influenza vaccine regimen that selectively enhanced IgG1 or IgG2a antibodies by using either DNA or viral replicon particle (VRP) vectors expressing influenza virus hemagglutinin (HA) (HA-DNA or HA-VRP, respectively). After HA-DNA vaccination, neutralizing antibodies were detected by both in vitro (microneutralization) and in vivo (lung viral titer) methods and were associated with increased IgG1 expression by enzyme-linked immunosorbent assay (ELISA). Vaccination with HA-VRP did not strongly stimulate either neutralizing or IgG1 antibodies but did induce IgG2a antibodies. Expression of IgG2a antibodies in this context correlated with clearance of virus and increased protection against lethal influenza challenge. Increased induction of both antibody isotypes as measured by ELISA was a better correlate for vaccine efficacy than neutralization alone. This study details separate but important roles for both IgG1 and IgG2a expression in vaccination against influenza and argues for the development of vaccine regimens that stimulate and measure expression of both antibody isotypes.

The possibility of trading greenhouse gas emission permits as a result of the Kyoto Protocol has spurred interest in developing land-based sinks for greenhouse gases. Extensive grazing lands that have the potential to develop substantial woody biomass are one obvious candidate for such activities. However, such activities need to consider the possible impacts on existing grazing and the possible impacts of continuing CO2 buildup in the atmosphere and resultant climate change. We used simulation models to investigate these issues in the mulga (Acacia aneura) woodlands of southwest Queensland. The simulation results suggest that this system can be managed to act as either a net source or a net sink of greenhouse gases under current climate and CO2 and under a range of global change scenarios. The key component in determining source or sink status is the management of the woody mulga. The most effective means of permanently increasing carbon stores and hence reducing net emissions is to exclude both burning and grazing. There are combinations of management regimes, such as excluding fire with light grazing, which, on average, allows productive grazing but transient carbon storage. The effects of increased CO2 on ecosystem carbon stores were unexpected. Carbon stores increased (7–17%) with doubling of CO2 only in those simulations where burning did not occur, but decreased when burnt. This occurred because the substantial increases in grass growth with doubling of CO2 (34–56%) enabled more fires, killing off the establishing cohorts needed to ensure continued carbon accumulation. On average, the doubling of atmospheric CO2 concentration increased grass growth by 44%, which is identical with mean literature values, suggesting that this result may be applicable in other ecosystems where fire has a similar function. A sensitivity analysis of the CO2 response of mulga showed only minor impacts. We discuss additional uncertainties and shortcomings. Keywords: Climate change, Carbon stores, Greenhouse emissions, Rangeland, Woodlands, Carbon dioxide, Impacts, Adaptation

No standardized PCR method is available for the laboratory diagnosis of the pertussis syndrome. Consensus recommendations for the use of PCR in the diagnosis of Bordetella pertussis infections have been proposed, and the aim of this study was to develop a method that fulfills all of these criteria. A rapid-cycle shared-primer PCR method with a microwell format and probe hybridization detection step (POR) was developed using novel oligonucleotides targeted to the outer membrane porin gene ( Bordetella spp.). In specimens positive for Bordetella spp., B. pertussis was differentiated from Bordetella parapertussis and Bordetella bronchiseptica by hybridization with organism-specific oligonucleotide probes. An internal control was developed using overlap extension PCR and mouse β-actin DNA. The analytical specificity was 100%. The analytical sensitivity was comparable to that of nested IS 481 and IS 1001 PCR (∼1 organism per reaction). The clinical sensitivity and specificity were ascertained using 705 specimens (from 705 patients). The results were compared to those of a nested-PCR method targeting the insertion sequences IS 481 and IS 1001 . Fifty-one specimens were positive for B. pertussis by POR and IS 481 PCR. Two specimens which fulfilled a clinical definition of pertussis were positive by POR and negative by IS 481 PCR. A total of 652 specimens were negative by both methods. B. parapertussis was not detected in any specimens. PCR inhibition was detected in 21 out of 705 specimens (2.98%). Thus, a rapid (4 h, including specimen preparation) PCR method which fulfills all of the consensus recommendations was developed and validated for the detection of B. pertussis .

Persistent infection of equids by equine infectious anemia virus (EIAV) is typically characterized by a progression during the first year postinfection from chronic disease with recurring disease cycles to a long-term asymptomatic infection that is maintained indefinitely. The goal of the current study was to perform a comprehensive longitudinal analysis of the course of virus infection and development of host immunity in experimentally infected horses as they progressed from chronic disease to long-term inapparent carriage. We previously described the evolution of EIAV genomic quasispecies (C. Leroux, C. J. Issel, and R. C. Montelaro, J. Virol. 71:9627–9639, 1997) and host immune responses (S. A. Hammond, S. J. Cook, D. L. Lichtenstein, C. J. Issel, and R. C. Montelaro, J. Virol. 71:3840–3852, 1997) in four experimentally infected ponies during sequential disease episodes associated with chronic disease during the first 10 months postinfection. In the current study, we extended the studies of these experimentally infected ponies to 3 years postinfection to characterize the levels of virus replication and development of host immune responses associated with the progression from chronic disease to long-term inapparent infection. The results of these studies revealed over a 10 3 -fold difference in the steady-state levels of plasma viral RNA detected during long-term inapparent infection that correlated with the severity of chronic disease, indicating different levels of control of virus replication during long-term inapparent infections. Detailed analyses of antibody and cellular immune responses in all four ponies over the 3-year course of infection revealed a similar evolution during the first year postinfection of robust humoral and cellular immunity that then remained relatively constant during long-term inapparent infection. These observations indicate that immune parameters that have previously been correlated with EIAV vaccine protection fail to provide reliable immune correlates of control of virus replication or clinical outcome in experimental infections. Thus, these data emphasize the differences between immunity to virus exposure and immune control of an established viral infection and further emphasize the need to develop and evaluate novel immunoassays to define reliable immune correlates to vaccine and infection immunity, respectively.

High levels of human immunodeficiency virus (HIV) type 1 have been detected in semen at all stages of disease. However, it is not clear whether HIV-1 is shed in semen continuously or intermittently. In a prospective longitudinal study, viral RNA was measured weekly for 10 weeks in semen and blood of HIV-seropositive subjects. Results showed three different patterns of HIV-1 shedding in semen: none (28%), continuous (28%), and intermittent (44%). In contrast, there was no change in blood plasma virus load during the study period. Phylogenetic analysis of the envelope sequences of HIV-1 RNA in semen and blood revealed distinct virus populations in semen and blood of intermittent shedders but similar virus populations in the semen and blood of continuous shedder. These results indicate for the first time that HIV-1 is shed primarily in an intermittent manner and that shedding patterns of HIV-1 in semen are related to compartmentalization of HIV-1 between semen and blood.

This study examined the potential to simulate the quality, as indicated by nitrogen concentration, of the diet of sheep grazing the Mitchell and mulga grasslands of western Queensland. Development of this simulation capability will allow pasture growth and animal production models to be more easily coupled. Modifications and optimisation of an existing beef cattle diet selection model, in conjunction with a single sward pasture model, accounted for 69.1% (P < 0.001) and 41.9% (P < 0.001) of variation in sheep dietary nitrogen concentrations observed from grazing trials on Mitchell and mulga grasslands, respectively. Failure to simulate some of the higher recorded dietary nitrogen concentrations was probably associated with high forb content in the diet. Examination of the results indicated that development of pasture growth models which simulate major pasture species, or groups of species (e.g. perennial grasses, annual grasses, browse, forbs, legumes), would appear to be necessary before diet selection models will be better able to explain the variation in dietary quality observed in grazing animals.

Field germination behaviour and seedbed environment of the annual legume Townsville stylo (Stylosanthes humilis) and the vigorous annual grass weed (Digitaria ciliaris) were studied at Katherine, Northern Territory. Previous studies of the population dynamics of these pastures had indicated the importance of the germination-establishment phase in maintaining S. humilis as a pasture component. Analysis of seed samples at the time of sward establishment showed that near complete germination of viable seed (in the case of D. ciliaris) and of soft seed (in the case of S. humilis) occurred in the early storm period before the onset of the wet season. Swards of both species generally resulted from a single, major germination wave often after an isolated rainfall. The seedbed environment at the time of major germination waves was studied in detail for 2 years and environmental models were used with historical climate records to calculate probability distributions of temperature and moisture over 16 years. The main determinants of the seedbed environment were storms (most often occurring in the period from late afternoon to midnight) and high solar radiation levels (70% > 20 MJ m-2 day-1 in the days after rainfall. Surface soil generally dries to -1.5 MPa by noon. Minimum night surface temperatures showed little variation (∼25°C) and were followed by high surface temperatures the following day (> 35°C). The use of a simple water balance model showed a high chance (80% of events) of the top 40 mm drying to – 1.5 MPa at the end of the second day following rainfall. Despite the low variation of annual rainfall at Katherine (cv of 20%) these self regenerating annual species have a high risk of seedling death. Germination and seedling establishment take place at a time of rapid fluctuations in surface moisture and seedbed temperature. The analysis of seedbed conditions indicated that intensive sampling of the seed population would be required in the early storm period to explain differential survival of the species and that laboratory work should concentrate on factors controlling speed of germination over short periods of available moisture (12–20 h).

Seed harvesting ants (mainly Pheidole spp.) in the Katherine area of the Northern Territory have been observed to actively forage seed in both native and sown pasture areas. Using discrete mixtures of seeds it was found that ants from colonies in both sown and native pastures would preferentially remove seed of the native grass species, Themeda australis and Digitaria ciliaris, to the introduced legume Stylosanthes humilis. This difference in selection could not be explained solely on a basis of size or weight differences between the species. The preference for grass species over introduced legumes indicates that ant predation is not the main factor in the low seed survival to germination in introduced pastures.

Environmental factors affecting speed of germination and survival of naturally occurring seed of the legume Stylosanthes humilis and the grass Digitaria ciliaris were studied. Previous studies on the seedbed environment had shown that germination speed, defined as the proportion of seeds capable of germinating in the first 12 h period, was likely to be the most relevant laboratory measurement. Ten studies were conducted to compare species performance and to devise a standard technique for the measurement of germination speed under laboratory conditions. For S. humilis, the level and duration of submergence in water in the germination test had a large effect on germination speed (from 0–70% in 12 h). The absence of light delayed germination (7% in 12 h compared to 52% under light), but did not prevent complete germination over 7 days. Optimum temperature was 25°C with a decrease to 0% at 30°C. A standard technique was developed for measuring potential germination speed which gave reproducible results allowing differences in seed lots to be described. D. ciliaris seeds sampled just prior to field germination in the early storm period were less sensitive to environmental control. Temperature optimum for germination decreased from 40 to 30°C with the duration of the germination test. Seeds sampled at the time of seed dispersal (early dry season) had a high fraction (80%) requiring light for germination but this requirement had been lost by the early storm period. Investigations on the role of leaching (water movement) showed that long periods of water movement (12–18 h) increased the speed of germination of both species and in the case of S. humilis overcame environmental blocks to rapid germination (absence of light or 30°C temperature). Root elongation rates in S. humilis were not greatly affected by temperature over the range of seedbed temperatures when moisture is available (25–40°C) in the field. However, D. ciliaris was delayed in development at 25°C, the most likely overnight surface soil temperature. D. ciliaris was more susceptible to death by desiccation once germination had occurred compared to S. humilis. In both species seedling death due to desiccation increased with stage of development. The better relative performance of S. humilis in the germination-establishment phase of the life cycle, which had been observed in a previous study, could be explained by a qualitative comparison of the species' attributes. This suggested that D. ciliaris was more likely to germinate at rainfall events following which there was a greater chance of seedling death

SUMMARYThe extent and rate of N release from nylon bags containing green panic (Panicum maximumvar.trichoglume)litter was measured for up to 319 days (long-term studies) in 1978/79 and 1979/80 in Gayndah, Australia. Dry matter (DM) decomposition rates were measured in 41 periods of 39 days and related to environmental variables and initial litter N concentrations (short-term study).About half of litter DM decomposed during the long-term studies, while N concentration in the remaining litter increased from an initial average of 0–57 % N, to 0–95 % N. Net release of N from bags began when its concentration in the residue increased to c.0–65% N (or when the C:N ratio decreased to 75:1). Only a net 20–30 % of the initial N was released for potential plant uptake by the end of the study. The short-term study showed that DM decomposition was rapid and independent of pasture age. Decomposition rate increased with soil moisture and average daily temperature but was unaffected by initial litter N concentration. Release of N from decomposing litter was slow, despite rapid DM decomposition. It was concluded that a major cause of declining productivity in sown grass pastures is the immobilization of N in decomposing grass litter.