Evolution of a minimal cell.

Possessing only essential genes, a minimal cell can reveal mechanisms and processes that are critical for the persistence and stability of life1,2. Here we report on how an engineered minimal cell3,4 contends with the forces of evolution compared with the Mycoplasma mycoides non-minimal cell from which it was synthetically derived. Mutation rates were the highest among all reported bacteria, but were not affected by genome minimization. Genome streamlining was costly, leading to a decrease in fitness of greater than 50%, but this deficit was regained during 2,000 generations of evolution. Despite selection acting on distinct genetic targets, increases in the maximum growth rate of the synthetic cells were comparable. Moreover, when performance was assessed by relative fitness, the minimal cell evolved 39% faster than the non-minimal cell. The only apparent constraint involved the evolution of cell size. The size of the non-minimal cell increased by 80%, whereas the minimal cell remained the same. This pattern reflected epistatic effects of mutations in ftsZ, which encodes a tubulin-homologue protein that regulates cell division and morphology5,6. Our findings demonstrate that natural selection can rapidly increase the fitness of one of the simplest autonomously growing organisms. Understanding how species with small genomes overcome evolutionary challenges provides critical insights into the persistence of host-associated endosymbionts, the stability of streamlined chassis for biotechnology and the targeted refinement of synthetically engineered cells2,7-9.

A proof-of-concept study comparing tinnitus and neural connectivity changes following multisensory perceptual training with and without a low-dose of fluoxetine.

Background. This proof-of-concept study investigated a method of multisensory perceptual training for tinnitus, and whether a short, low-dose administration of fluoxetine enhanced training effects and changed neural connectivity.Methods. A double-blind, randomized placebo controlled design with 20 participants (17 male, 3 female, mean age = 57.1 years) involved 30 min daily computer-based, multisensory training (matching visual, auditory and tactile stimuli to perception of tinnitus) for 20 days, and random allocation to take 20 mg fluoxetine or placebo daily. Behavioral measures of tinnitus and correlations between pairs of a priori regions of interest (ROIs), obtained using resting-state functional magnetic resonance imaging (rs-fMRI), were performed before and after the training.Results. Significant changes in ratings of tinnitus loudness, annoyance, and problem were observed with training. No statistically significant changes in Tinnitus Functional Index, Tinnitus Handicap Inventory or Depression Anxiety Stress Scales were found with training. Fluoxetine did not alter any of the behavioural outcomes of training compared to placebo. Significant changes in connectivity between ROIs were identified with training; sensory and attention neural network ROI changes correlated with significant tinnitus rating changes. Rs-fMRI results suggested that the direction of functional connectivity changes between auditory and non-auditory networks, with training and fluoxetine, were opposite to the direction of those changes with multisensory training and placebo.Conclusions. Improvements in tinnitus measures were correlated with changes in sensory and attention networks. The results provide preliminary evidence for changes in rs-fMRI accompanying a multisensory training method in persons with tinnitus.

A proof-of-principle study of the short-term effects of 3,4-methylenedioxymethamphetamine (MDMA) on tinnitus and neural connectivity.

Background: This study was conducted to investigate the short-term behavioural and neurophysiological effects of 3,4-methylenedioxymethamphetamine (MDMA) on tinnitus perception.Methods: A double-blind randomized controlled cross-over design. Part 1. Behavioural measures of tinnitus following 30 mg MDMA or placebo administration (N = 5 participants) and Part 2. Behavioural measures of tinnitus and correlations between pairs of apriori regions of interest (ROI) using resting-state functional magnetic resonance imaging (rs-fMRI) before and after 70 mg of MDMA or placebo (N = 8 participants).Results: The results to MDMA were similar to placebo. For the 70 mg dose, there was a significant reduction after 4 h in annoyance and ignore ratings. RsMRI showed decreased connectivity compared with placebo administration between the left hippocampal, right hippocampal, left amygdala and right amygdala regions, and between the right posterior parahippocampal cortex and the left amygdala after two hours of 70 mg MDMA administration. Increased connectivity compared to placebo administration was found post MDMA between the right post-central gyrus and right posterior and superior temporal gyrus, and between the thalamus and frontoparietal network.Conclusions: Following 70 mg of MDMA two tinnitus rating scales significantly improved. There was, however, a placebo effect. Compared with placebo the rsMRI following the MDMA showed reductions in connectivity between the amygdala, hippocampus and parahippocampal gyrus. There is sufficient proof of concept to support future investigation of MDMA as a treatment for tinnitus.

Integrated Effects of Genetic Resistance and Prothioconazole + Tebuconazole Application Timing on Fusarium Head Blight in Wheat.

Integrated Fusarium head blight (FHB) management programs consisting of different combinations of cultivar resistance class and an application of the fungicide prothioconazole + tebuconazole at or after 50% early anthesis were evaluated for efficacy against FHB incidence (INC; percentage of diseased spikes), index (IND; percentage of diseased spikelets per spike), Fusarium damaged kernel (FDK), deoxynivalenol (DON) toxin contamination, grain yield, and test weight (TW) in inoculated field trials conducted in 11 U.S. states in 2014 and 2015. Mean log response ratios and corresponding percent control values for INC, IND, FDK, and DON, and mean differences in yield and TW relative to a nontreated, inoculated susceptible check (S_CK), were estimated through network meta-analyses as measures of efficacy. Results from the analyses were then used to estimate the economic benefit of each management program for a range of grain prices and fungicide applications costs. Management programs consisting of a moderately resistant (MR) cultivar treated with the fungicide were the most efficacious, reducing INC by 60 to 69%, IND by 71 to 76%, FDK by 66 to 72%, and DON by 60 to 64% relative to S_CK, compared with 56 to 62% for INC, 68 to 72% for IND, 66 to 68% for FDK, and 58 to 61% for DON for programs with a moderately susceptible (MS) cultivar. The least efficacious programs were those with a fungicide application to a susceptible (S) cultivar, with less than a 45% reduction of INC, IND, FDK, or DON. All programs were more efficacious under conditions favorable for FHB compared with less favorable conditions, with applications made at 50% early anthesis being of comparable efficacy to those made 2 to 7 days later. Programs with an MS cultivar resulted in the highest mean yield increases relative to S_CK (541 to 753 kg/ha), followed by programs with an S cultivar (386 to 498 kg/ha) and programs with an MR cultivar (250 to 337 kg/ha). Integrated management programs with an MS or MR cultivar treated with the fungicide at or after 50% early anthesis were the most likely to result in a 50 or 75% control of IND, FDK, or DON in a future trial. At a fixed fungicide application cost, these programs were $4 to $319/MT more economically beneficial than corresponding fungicide-only programs, depending on the cultivar and grain price. These findings demonstrate the benefits of combining genetic resistance with a prothioconazole + tebuconazole treatment to manage FHB, even if that treatment is applied a few days after 50% early anthesis.

Meta-Analysis of the Effects of QoI and DMI Fungicide Combinations on Fusarium Head Blight and Deoxynivalenol in Wheat.

Field trials were conducted in 17 U.S. states to evaluate the effects of quinone outside inhibitor (QoI) and demethylation inhibitor (DMI) fungicide programs on Fusarium head blight index (IND) and deoxynivalenol (DON) toxin in wheat. Four DMI-only treatments applied at Feekes 10.5.1, five QoI-only treatments applied between Feekes 9 or Feekes 10.5, three QoI+DMI mixtures applied at Feekes 10.5, and three treatments consisting of a QoI at Feekes 9 followed by a DMI at Feekes 10.5.1 were evaluated. Network meta-analytical models were fitted to log-transformed mean IND and DON data and estimated contrasts of log means were used to obtain estimates of mean percent controls relative to the nontreated check as measures of efficacy. Results from the meta-analyses were also used to assess the risk of DON increase in future trials. DMI at Feekes 10.5.1 were the most effective programs against IND and DON and the least likely to increase DON in future trials. QoI-only programs increased mean DON over the nontreated checks and were the most likely to do so in future trials, particularly when applied at Feekes 10.5. The effects of QoI+DMI combinations depended on the active ingredients and whether the two were applied as a mixture at heading or sequentially. Following a Feekes 9 QoI application with a Feekes 10.5.1 application of a DMI reduced the negative effect of the QoI on DON but was not sufficient to achieve the efficacy of the Feekes 10.5.1 DMI-only treatments. Our results suggest that one must be prudent when using QoI treatments under moderate to high risk of FHB, particularly where the QoI is used without an effective DMI applied in combination or in sequence.

ESTIMATES OF RADIATION DOSES TO THE SKIN FOR PEOPLE CAMPED AT WALLATINNA DURING THE UK TOTEM 1 ATOMIC WEAPONS TEST.

A group of Aboriginal people was camped at Wallatinna in South Australia, ~170 km downwind from Emu Field, where an atomic test (the Totem 1 test) was carried out at 07.00 on 15 October 1953 local time (21.30 on 14 October 1953 GMT (Greenwich Mean Time)). They left the camp ~24 hours later. These people stated that a phenomenon that has become known as a 'black mist' rolled through their camp site ~5 hours after detonation and that some of them subsequently became sick, displaying skin reddening and nausea. They feared that the sickness was a result of exposure to high levels of radiation. The purpose of this paper is to determine if these people could have received ionising radiation doses high enough to cause the symptoms displayed. The methodology used for the dose estimates is described in the paper. The exposure modes considered were external exposure due to the passage of a contaminated plume over the camp site, inhalation of material from this plume, external exposure from material deposited on the ground as the plume passed, and consumption of contaminated food and water. The contaminants considered in the airborne cloud and the ground plume were fission products and unburnt plutonium from the nuclear detonation, and neutron activation products caused by vaporisation of the tower used to position the weapon. The source was approximated by a line source. An upper estimate of the effective doses received is ~4 mSv, which is well below the level at which acute radiation effects are observed. This estimate is consistent with earlier assessments, which did not consider inhalation of the contribution from neutron activation products.

Pathotype Diversity of Phytophthora sojae in Eleven States in the United States.

Pathotype diversity of Phytophthora sojae was assessed in 11 states in the United States during 2012 and 2013. Isolates of P. sojae were recovered from 202 fields, either from soil samples using a soybean seedling bioassay or by isolation from symptomatic plants. Each isolate was inoculated directly onto 12 soybean differentials; no Rps gene or Rps 1a, 1b, 1c, 1k, 3a, 3b, 3c, 4, 6, 7, or 8. There were 213 unique virulence pathotypes identified among the 873 isolates collected. None of the Rps genes were effective against all the isolates collected but Rps6 and Rps8 were effective against the majority of isolates collected in the northern regions of the sampled area. Virulence toward Rps1a, 1b, 1c, and 1k ranged from 36 to 100% of isolates collected in each state, while virulence to Rps6 and Rps8 was less than 36 and 10%, respectively. Depending on the state, the effectiveness of Rps3a ranged from totally effective to susceptible to more than 40% of the isolates. Pathotype complexity has increased in populations of P. sojae in the United States, emphasizing the increasing importance of stacked Rps genes in combination with high partial resistance as a means of limiting losses to P. sojae.

Efficient assembly of multi-color fiberless optoelectrodes with on-board light sources for neural stimulation and recording.

Fiberless optoelectrodes are an emerging tool to enable brain circuit mapping by providing precise optical modulation and electrical monitoring of many neurons. While optoelectrodes having an on-board light source offer compact and optically efficient device solutions, many of them fail to provide robust thermal and electrical design to fully exploit the recording capabilities of the device. In this work, we present a novel fiberless multicolor optoelectrode solution, which meets the optical and thermal design requirements of an in vivo neural optoelectrode and offers potential for low-noise neural recording. The total optical loss measured for 405 nm and 635 nm wavelengths through the waveguide is 11.7±1.1 dB and 9.9±0.7 dB, corresponding to respective irradiances of 1928 mW/mm2 and 2905 mW/mm2 at the waveguide tip from 6 mW laser diode chips. The efficient thermal packaging enables continuous device operation for up to 190 seconds at 10% duty cycle. We validated the fully packaged device in the intact brain of anesthetized mice co-expressing Channelrhodopsin-2 and Archaerhodopsin in the hippocampal CA1 region and achieved activation and silencing of the same neurons. We discuss improvements made to reduce the stimulation artifact induced by applying currents to the laser diode chips.

Feasibility study of a game integrating assessment and therapy of tinnitus.

BACKGROUND: Tinnitus, head and ear noise, is due to maladaptive plastic changes in auditory and associated neural networks. Tinnitus has been traditionally managed through the use of sound to passively mask or facilitate habituation to tinnitus, a process that may take 6-12 months. NEW METHOD: A game-based perceptual training method, requiring localisation and selective attention to sounds, was developed and customised to the individual's tinnitus perception. Eight participants tested the games usability at home. RESULTS: Each participant successfully completed 30 min of training, for 20 days, along with daily psychoacoustic assessment of tinnitus pitch and loudness. The training period and intensity of training appears sufficient to reduce tinnitus handicap. COMPARISON WITH EXISTING METHOD(S): The training approach used may be a viable alternative to frequency discrimination based training for treating tinnitus (Hoare et al., 2014) and a useful tool in exploring learning mechanisms in the auditory system. CONCLUSIONS: Integration of tinnitus assessment with therapy in a game is feasible, and the method(s) warrant further investigation.

Revisiting Fungicide-Based Management Guidelines for Leaf Blotch Diseases in Soft Red Winter Wheat.

Standard foliar fungicide applications in wheat are usually made between flag leaf emergence (Feekes [FK] 8) and heading (FK10.5) to minimize damage to the flag leaf. However, over the last few years, new fungicide programs such as applications prior to FK8 and split half-rate applications have been implemented, although there are few data pertaining to the efficacy of these programs. Eight experiments were conducted in Illinois, Indiana, Ohio, and Wisconsin from 2010 to 2012 to compare new programs to standard FK8 and FK10 programs in terms of disease control and yield response. The programs evaluated consisted of single full-rate applications of 19% tebuconazole + 19% prothioconazole (Prosaro) or 23.6% pyraclostrobin (Headline) at FK5 (pseudostem strongly erected), FK8, or FK10, or split half rates at FK5 and 8 (FK5+8), plus an untreated check (CK). Leaf blotch (LB) severity and yield data were collected and random effects meta-analytical models fitted to estimate the overall log odds ratio of disease reaching the flag leaf ( L¯OR ) and mean yield increase ( D¯ ) for each fungicide program relative to CK. For all programs, L¯OR was significantly different from zero (P < 0.05). Based on estimated odds ratios (OR = exp[ L¯OR ]), the two FK8 programs reduced the risk of LB reaching the flag leaf by 55 and 75%, compared with 62 and 69% and 67 and 70% for the two FK10 and FK5+8 programs, respectively, and only 32 and 37% for the two FK5 programs. D¯ was significantly different from zero (P ≤ 0.003) for all FK8, FK10, and FK5+8 programs, with values of 233 and 245, 175 and 220, and 175 and 187 kg ha-1 for the FK10, FK5+8, and FK8 programs, respectively. Differences in mean yield response between Headline and Prosaro were not statistically significant (P > 0.05). The probability of profitability was estimated for each program for a range of grain prices and fungicide application costs. All FK8, FK10, and FK5+8 programs had more than an 80% chance of resulting in a positive yield response, compared with 63 and 67% for the two FK5 programs. The chance of obtaining a yield increase of 200 kg ha-1, required to offset an application cost of $36 ha-1 at a grain price of $0.18 kg-1, ranged from 44 to 60% for FK8, FK10 and FK5+8 programs compared with 22 and 25% for the two FK5 programs. These findings could be used to help inform fungicide application decisions for LB diseases in soft red winter wheat.

Development of Molecular Assays for Detection of Stenocarpella maydis and Stenocarpella macrospora in Corn.

The causal agents of Diplodia ear rot are two species of the Stenocarpella genus, S. macrospora and S. maydis. In addition to ears, both pathogens can infect leaves and stalks, and both are present in most corn-production regions around the world. It is difficult to visually distinguish between the two pathogens based on plant symptoms and fungal signs. To facilitate accurate and rapid pathogen identification, polymerase chain reaction (PCR) assays were developed for identification of each species. Species-specific primers of 18 to 20 nucleotides in length were designed, targeting a portion of the internal transcribed spacer (ITS) region of the fungal genome for conventional and real-time PCR assays. The conventional PCR method successfully amplified a single 1.7-kb and 800-bp fragment for each S. maydis and S. macrospora isolate, respectively. The real-time method was performed using SYBR green dye, and detection of each specific target pathogen was successfully obtained. In total, 82 S. maydis and 15 S. macrospora isolates were tested to evaluate the reproducibility of these primers. Both methods provide a rapid and specific tool for the detection of Stenocarpella spp.

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.

Efficacy and Stability of Integrating Fungicide and Cultivar Resistance to Manage Fusarium Head Blight and Deoxynivalenol in Wheat.

Integration of host resistance and prothioconazole + tebuconazole fungicide application at anthesis to manage Fusarium head blight (FHB) and deoxynivalenol (DON) in wheat was evaluated using data from over 40 trials in 12 U.S. states. Means of FHB index (index) and DON from up to six resistance class-fungicide management combinations per trial (susceptible treated [S_TR] and untreated [S_UT]; moderately susceptible treated [MS_TR] and untreated [MS_UT]; moderately resistant treated [MR_TR] and untreated [MR_UT]) were used in multivariate meta-analyses, and mean log response ratios across trials were estimated and transformed to estimate mean percent control ( ) due to the management combinations relative to S_UT. All combinations led to a significant reduction in index and DON (P < 0.001). MR_TR was the most effective combination, with a of 76% for index and 71% for DON, followed by MS_TR (71 and 58%, respectively), MR_UT (54 and 51%, respectively), S_TR (53 and 39%, respectively), and MS_UT (43 and 30%, respectively). Calculations based on the principle of treatment independence showed that the combination of fungicide application and resistance was additive in terms of percent control for index and DON. Management combinations were ranked based on percent control relative to S_UT within each trial, and nonparametric analyses were performed to determine management combination stability across environments (trials) using the Kendall coefficient of concordance (W). There was a significant concordance of management combinations for both index and DON (P < 0.001), indicating a nonrandom ranking across environments and relatively low variability in the within-environment ranking of management combinations. MR_TR had the highest mean rank (best control relative to S_UT) and was one of the most stable management combinations across environments, with low rank stability variance (0.99 for index and 0.67 for DON). MS_UT had the lowest mean rank (poorest control) but was also one of the most stable management combinations. Based on Piepho's nonparametric rank-based variance homogeneity U test, there was an interaction of management combination and environment for index (P = 0.011) but not for DON (P = 0.147), indicating that the rank ordering for index depended somewhat on environment. In conclusion, although the magnitude of percent control will likely vary among environments, integrating a single tebuconazole + prothioconazole application at anthesis with cultivar resistance will be a more effective and stable management practice for both index and DON than either approach used alone.

Meta-analysis of yield response of hybrid field corn to foliar fungicides in the U.S. Corn Belt.

The use of foliar fungicides on field corn has increased greatly over the past 5 years in the United States in an attempt to increase yields, despite limited evidence that use of the fungicides is consistently profitable. To assess the value of using fungicides in grain corn production, random-effects meta-analyses were performed on results from foliar fungicide experiments conducted during 2002 to 2009 in 14 states across the United States to determine the mean yield response to the fungicides azoxystrobin, pyraclostrobin, propiconazole + trifloxystrobin, and propiconazole + azoxystrobin. For all fungicides, the yield difference between treated and nontreated plots was highly variable among studies. All four fungicides resulted in a significant mean yield increase relative to the nontreated plots (P < 0.05). Mean yield difference was highest for propiconazole + trifloxystrobin (390 kg/ha), followed by propiconazole + azoxystrobin (331 kg/ha) and pyraclostrobin (256 kg/ha), and lowest for azoxystrobin (230 kg/ha). Baseline yield (mean yield in the nontreated plots) had a significant effect on yield for propiconazole + azoxystrobin (P < 0.05), whereas baseline foliar disease severity (mean severity in the nontreated plots) significantly affected the yield response to pyraclostrobin, propiconazole + trifloxystrobin, and propiconazole + azoxystrobin but not to azoxystrobin. Mean yield difference was generally higher in the lowest yield and higher disease severity categories than in the highest yield and lower disease categories. The probability of failing to recover the fungicide application cost (p(loss)) also was estimated for a range of grain corn prices and application costs. At the 10-year average corn grain price of $0.12/kg ($2.97/bushel) and application costs of $40 to 95/ha, p(loss) for disease severity <5% was 0.55 to 0.98 for pyraclostrobin, 0.62 to 0.93 for propiconazole + trifloxystrobin, 0.58 to 0.89 for propiconazole + azoxystrobin, and 0.91 to 0.99 for azoxystrobin. When disease severity was >5%, the corresponding probabilities were 0.36 to 95, 0.25 to 0.69, 0.25 to 0.64, and 0.37 to 0.98 for the four fungicides. In conclusion, the high p(loss) values found in most scenarios suggest that the use of these foliar fungicides is unlikely to be profitable when foliar disease severity is low and yield expectation is high.

Effect of Postsymptom Application of Fungicides on Urediniospore Production by Puccinia triticina on Wheat and P. hemerocallidis on Daylily.

Greenhouse experiments were conducted to evaluate the effect of post-symptomatic fungicide applications on urediniospore production of leaf rust of wheat, Puccinia triticina, and daylily rust, P. hemerocallidis. Fungicides from five chemical classes were evaluated for their effect on urediniospore production at 24-h intervals post application for 96 h. The quinone outside inhibitor (QoI) fungicide (azoxystrobin) significantly reduced cumulative urediniospore production by P. triticina (40.1 and 11.3% of control) and P. hemerocallidis (37.9 and 35.6% of control) in both trials. The demethylation inhibitor, myclobutanil, significantly reduced urediniospore production by P. hemerocallidis 24 h post treatment in both trials and cumulative production in one trial. Myclobutanil did not affect urediniospore production by P. triticina. Four QoI fungicides significantly reduced urediniospore production by P. triticina at all collection times (24, 48, and 72 h) and cumulative production in both trials. No differences were observed between the QoI fungicides with P. triticina. The four QoI fungicides significantly reduced urediniospore production by P. hemerocallidis compared with the nonfungicide control, with significantly fewer urediniospores produced in the pyraclostrobin-treated lesions compared with azoxystrobin, fluoxastrobin, and trifloxystrobin. Differences in leaf morphology between daylily and wheat such as leaf thickness and waxiness may contribute to the differences observed between the two pathosystems. The significant reductions in urediniospore production by postsymptom applications of QoI fungicides, combined with their known fungistatic properties, suggest that these chemistries would be useful for reducing the spread of viable inoculum to noninfested plants.

Contribution of serum inflammatory markers to changes in bone mineral content and density in postmenopausal women: a 1-year investigation.

Bone formation and resorption are influenced by inflammatory processes. We examined the relationships among inflammatory markers and bone mineral content (BMC) and density (BMD) and determined the contribution of inflammatory markers to 1-yr changes in BMC and BMD in healthy postmenopausal women. This analysis included 242 women at baseline from our parent Soy Isoflavones for Reducing Bone Loss project who were randomly assigned to 1 of 3 treatment groups: placebo, 80 mg/d soy isoflavones, or 120 mg/d soy isoflavones. BMD and BMC from the lumbar spine (LS), total proximal femur (hip), and whole body were measured by dual energy X-ray absorptiometry and the 4% distal tibia by peripheral quantitative computed tomography. Serum inflammatory markers (C-reactive protein, interleukin [IL]-1 beta, IL-6, tumor necrosis factor-alpha [TNF-alpha], and white blood cell count [WBC]) were measured at baseline, 6, and 12 mo. Because of attrition or missing values, data analysis at 12 mo includes only 235 women. Significant associations among IL-6, TNF-alpha, and WBC were observed with percent change in LS, hip, and whole body BMC and BMD. Multiple regression analysis indicated that in combination inflammatory markers accounted for 1.1-6.1% of the variance to the observed 12-mo changes in BMC and BMD. Our results suggest that modifying inflammatory markers, even in healthy postmenopausal women, may possibly reduce bone loss.

Resistance to QoI Fungicides in Ascochyta rabiei from Chickpea in the Northern Great Plains.

Ascochyta blight, caused by Ascochyta rabiei (teleomorph: Didymella rabiei), is an important fungal disease of chickpea (Cicer arietinum). A monitoring program was established in 2005 to determine the sensitivity of A. rabiei isolates to the QoI (strobilurin) fungicides azoxystrobin and pyraclostrobin. A total of 403 isolates of A. rabiei from the Northern Great Plains and the Pacific Northwest were tested. Ninety-eight isolates collected between 2005 and 2007 were tested using an in vitro spore germination assay to determine the effective fungicide concentration at which 50% of conidial germination was inhibited (EC50) for each isolate-fungicide combination. A discriminatory dose of 1 µg/ml azoxystrobin was established and used to test 305 isolates from 2006 and 2007 for in vitro QoI fungicide sensitivity. Sixty-five percent of isolates collected from North Dakota in 2005, 2006, and 2007 and from Montana in 2007 were found to exhibit a mean 100-fold decrease in sensitivity to both azoxystrobin and pyraclostrobin when compared to sensitive isolates, and were considered to be resistant to azoxystrobin and pyraclostrobin. Under greenhouse conditions, QoI-resistant isolates of A. rabiei caused significantly higher amounts of disease than sensitive isolates on azoxystrobin- or pyraclostrobin-amended plants. These results suggest that disease control may be inadequate at locations where resistant isolates are present.

First Report of Goss's Bacterial Wilt and Leaf Blight on Corn Caused by Clavibacter michiganensis subsp. nebraskensis in Indiana.

In August of 2008, leaves of hybrid corn (Zea mays L.) and popcorn from Pulaski and Jasper counties in northwest Indiana were submitted to the Purdue Plant and Pest Diagnostic Lab with symptoms characteristic of a bacterial disease. Symptomatic leaves had large, tan-to-gray necrotic lesions with dark freckling present within the lesions. Shiny bacterial exudate was present on the surface of many of the lesions. Microscopic observation revealed no fungal structures within the lesions, and bacterial streaming was observed from the cut edge of symptomatic tissue under ×100 magnification with phase contrast. A commercially available ELISA test (Agdia Inc., Elkhart, IN) determined that samples were negative for Pantoea stewartii, the causal agent of Stewart's bacterial leaf blight and wilt. A bacterial suspension was prepared from symptomatic tissue and streaked onto King's B medium and subcultured on semiselective CNS medium (1,2). Axenic, peach-colored colonies present on the CNS medium tested gram positive with a KOH test. Analysis of fatty acid methyl esters (MIDI Inc, Newark, DE) indicated that the strain was very similar (0.611) to Clavibacter michiganensis. Amplification of the 500-bp 16S rRNA region of the bacterial gene and subsequent BLAST alignments of the resulting sequence indicated a 99% match for C. michiganensis subsp. nebraskensis (GenBank Accession Nos. AM410697 and U09763; D16S2 gene bacterial library, version 2.10; MIDI Inc,). Koch's postulates were used to confirm pathogenicity of the isolated bacteria on corn inbred B73. Eighteen plants were mechanically inoculated at growth stage V1 to V2 with a bacterial suspension of approximately 1 × 108 CFU/ml prepared from cultures grown on CNS for 10 days at 28°C (2). Inoculum was rubbed onto leaves dusted with Carborundum and 0.1 ml of the bacterial suspension was injected into stems with a hypodermic needle. Nine control plants were inoculated with sterile water. Plants were kept at greenhouse conditions (24°C) with supplemental 400W high-pressure sodium light. Within 5 to 8 days, leaves and stems of all 18 inoculated plants developed water-soaked, necrotic lesions. No symptoms were observed in control plants. Bacteria were reisolated from symptomatic plants on CNS medium as described above, and gram-positive colonies were obtained. Reisolated strains were identical to C. michiganensis subsp. nebraskensis by D16S2 DNA sequence analysis, confirming the causal agent of the disease. Disease incidence in affected fields ranged from 20 to 60% and significant yield loss was reported. This confirmation is of regulatory importance because of potential export restrictions of Indiana-grown seed corn and popcorn to select countries. To our knowledge, this is the first report of Goss's bacterial wilt and leaf blight on corn in Indiana. References: (1) D. C. Gross and A. K. Vidaver. Phytopathology 69:82, 1979. (2) L. M. Shepherd. M.S. thesis. Iowa State University. Ames, 1999.