Learning and memory is modulated by cannabidiol when administered during trace fear-conditioning.

Cannabidiol (CBD) is thought to have therapeutic potential for treating psychiatric conditions that affect cognitive aspects of learning and memory, including anxiety and post-traumatic stress disorder (PTSD). Studies have shown that CBD enhances extinction of fear memory when given after conditioning. This led us to hypothesize that CBD, if administered prior to fear conditioning, might modulate cognitive learning and memory processes in additional ways that would further guide its potential use for treating PTSD. Therefore, we designed a study to investigate effects of CBD on fear learning and memory when administered to mice prior to administering a trace fear conditioning protocol which imposes cognitive demands on the learning and memory process. We show that CBD-treated animals had increased levels of freezing during conditioning, enhanced generalized fear, inhibited cue-dependent memory extinction, slightly increased levels of freezing during an auditory-cued memory test, and increased contextual fear memory. Because synaptic plasticity is the fundamental mechanism of learning and memory, we also evaluated the impact of CBD on trace conditioning-dependent dendritic spine plasticity which occurred in the dorsal lateral amygdala and CA1 region of the ventral hippocampus. We showed that CBD mildly enhanced spine densities independent of conditioning, and inhibited conditioning-dependent spine increases in the hippocampi, but not the amygdala of fear conditioned animals. Overall, the memory-modulating effects of a single pre-conditioning dose of CBD, which we show here, demonstrate the need to more fully characterize its basic effects on memory, suggest caution when using it clinically as an anxiolytic, and point to a need for more research into its potential as a therapeutic for treating memory-loss disorders.

First Report of Bacterial Leaf Blight on Mustard Greens (Brassica juncea) Caused by Pseudomonas cannabina pv. alisalensis in Mississippi.

In 2010, a brassica leafy greens grower in Sunflower County, MS, observed scattered outbreaks of a leaf blight on mustard greens (Brassica juncea) in a 180-ha field. A severe outbreak of leaf blight occurred on mustard greens and turnip greens (B. rapa) in the same field in 2011 with more than 80 ha affected. The affected field, established in 2010, had no prior history of being cropped to brassica leafy greens. Symptoms appeared on the 6-week-old transplants as brown to tan necrotic spots with faint chlorotic borders and associated water-soaking. Lesions varied from 4 mm to 3 cm in diameter and often coalesced to cover >90% of older leaves. Whole plants of the mustard greens cv. Florida Broadleaf were collected in 2011 from the symptomatic field. Leaves were surface-disinfested with 0.5% NaOCl for 5 min, rinsed twice in sterilized distilled water [(sd)H2O], macerated in sdH2O, then streaked onto nutrient agar (NA), pseudomonas agar F (PAF), and potato dextrose agar (PDA). Little or no bacterial growth was observed on PDA, while on NA and PAF the majority of bacterial growth appeared to be a single colony type. All strains collected (25 total, one per plant) were gram-negative and fluoresced blue-green under UV light after 48 h at 28°C on PAF. All 25 strains were identified as belonging to Pseudomonas group 1a using Lelliot's determinative assay (2). Ten of the 25 strains were tested for pathogenicity on Florida Broadleaf, and turnip greens cv. Alamo. Bacteria were grown on PAF for 48 h, and a bacterial suspension was prepared and adjusted to an optical density of 0.1 at 600 nm. Three-week-old plants (three plants per cultivar) were sprayed with the appropriate bacterial suspension to runoff, placed at 100% relative humidity for 48 h, and then put in a growth chamber at 28°C with a 16-h diurnal light cycle for 14 days. Additionally, three plants each of Florida Broadleaf and Alamo were either sprayed with H2O or inoculated with Pseudomonas cannabina pv. alisalensis (Pca) pathotype strain BS91 (1). All 10 strains, as well as the Pca pathotype strain, were pathogenic on both cultivars and caused symptoms similar to those observed in the field. Symptoms were not observed on H2O-sprayed plants. Comparative rep-PCR analysis using the BOXA1R primer showed the 10 strains had identical DNA-banding profiles and were identical to that of Pca BS91 (5). Five strains tested using a Pca-specific, 'light-tagged' reporter bacteriophage gave a strong positive reaction, while a negative control strain, P. syringae pv. maculicola, gave no signal (3). From these tests, the isolated bacteria were determined to be Pca. Bacteria re-isolated on PAF from the inoculated Florida Broadleaf plants had identical rep-PCR profiles with those of the strains used for inoculations. Over the past 10 years, Pca has been found in numerous states in the United States, as well as in Europe, Australia, and Japan (4). As brassica leafy greens production expands to new fields and new states, leaf blight caused by Pca appears to become a problem rapidly. Since resistant cultivars and highly effective bactericides are lacking, growers are extremely concerned about the rapid spread of this disease into existing and new brassica leafy greens regions. References: (1) N. A. Cintas et al. Plant Dis. 86:992, 2002. (2) R. Lelliott. J. Appl. Bacteriol. 29:470, 1066. (3) D. Schofield et al. Appl. Environ. Microbiol. 78:3592, 2012. (4) F. Takahashi et al. J. Gen. Plant Pathol. 79:260, 2013. (5) J. Versalovic et al. Methods Mol. Cell Biol 5:25, 1994.

Who pays for the health benefits of exclusive breastfeeding? An analysis of maternal time costs.

BACKGROUND: The benefits of exclusive breastfeeding, including public health cost savings, are widely recognized, but breastfeeding requires maternal time investments. OBJECTIVE: This study investigates the time taken to exclusively breastfeed at 6 months compared with not exclusively breastfeeding. METHODS: Time use data were examined from an Australian survey of new mothers conducted during 2005-2006. Data from 139 mothers with infants age 6 months were analyzed using chi-square tests of independence to examine socioeconomic and demographic characteristics and 2-sided t tests to compare average weekly hours spent on milk feeding, feeding solids, preparing feeds, and the total of these. The comparison was of exclusively breastfeeding mothers with other mothers. We also compared exclusively breastfeeding with partially breastfeeding and formula feeding mothers using a 1-way between-groups analysis of variance (ANOVA). RESULTS: The exclusively breastfeeding (vs other) mothers spent 7 hours extra weekly on milk feeding their infants but 2 hours less feeding solids. These differences were statistically significant. ANOVA revealed significant differences between exclusively breastfeeding mothers, breastfeeding mothers who had introduced solids, and mothers who fed any formula, in time spent feeding milk, and solids, and preparing feeds. CONCLUSION: Exclusive breastfeeding is time intensive, which is economically costly to women. This may contribute to premature weaning for women who are time-stressed, lack household help from family, or cannot afford paid help. Gaining public health benefits of exclusive breastfeeding requires strategies to share maternal lactation costs more widely, such as additional help with housework or caring for children, enhanced leave, and workplace lactation breaks and suitable child care.

"Lost milk?": Counting the economic value of breast milk in gross domestic product.

BACKGROUND: The contribution of breastfeeding and mothers milk to the economy is invisible in economic statistics. OBJECTIVE: This article demonstrates how the economic value of human milk production can be included in economic statistics such as gross domestic product (GDP) and provides estimates for Australia, the United States, and Norway. METHODS: The contribution of human milk and lactation to GDP in these countries is estimated using United Nations (System of National Accounting) guidelines and conventional economic valuation approaches to measuring production in GDP. RESULTS: In Australia, current human milk production levels exceed $3 billion annually. The United States has the potential to produce human milk worth more than US$110 billion a year, but currently nearly two thirds of this value is lost due to premature weaning. In Norway, production valued at US$907 million annually is 60% of its potential value. CONCLUSIONS: The potential loss of economic value from not protecting women's lactation and milk production from competing market pressures is large. Failure to account for mothers' milk production in GDP and other economic data has important consequences for public policy. The invisibility of human milk reduces the perceived importance of programs and regulations that protect and support women to breastfeed. The value of human milk can be measured using accepted international guidelines for calculating national income and production. It is quantitatively nontrivial and should be counted in GDP.

Predictors of asymmetric dimethylarginine levels in patients with rheumatoid arthritis: the role of insulin resistance.

OBJECTIVE: To determine whether demographic, inflammatory, and metabolic factors predict elevated asymmetric dimethylarginine (ADMA) levels in rheumatoid arthritis (RA). METHOD: A total of 67 RA patients [mean age 56 ± 12 years, median disease duration 8 (3-15) years] were assessed. Routine biochemistry tests, lipid profile, glycaemic profile [glucose, insulin, homeostasis model assessment (HOMA), quantitative insulin sensitivity check index (QUICKI)], and inflammatory markers were measured in all patients. ADMA levels were measured by enzyme-linked immunosorbent assay (ELISA). Regression analyses were performed to identify predictors of ADMA in RA. RESULTS: Regression analysis revealed that HOMA (ß = 0.149, p = 0.003) was an independent predictor of ADMA in RA. From the drug factors, anti-hypertensive medication use was associated with lower ADMA levels (ß = -0.081, p = 0.004). ADMA was not associated with RA disease-related parameters or any of the other cardiovascular risk factors that were assessed. CONCLUSIONS: HOMA, a strong indicator of insulin resistance, seems to be the main predictor of elevated ADMA levels in RA patients; ADMA may reflect an important pathway linking abnormal insulin metabolism with endothelial dysfunction in RA.

Expression of Bacterial Blight Resistance in Brassica Leafy Greens Under Field Conditions and Inheritance of Resistance in a Brassica juncea Source.

Brassica leafy greens are one of the most economically important vegetable commodity groups grown in the southeastern United States, and more than 28,000 metric tons of these crops are harvested in the United States annually. Collard and kale (Brassica oleracea Acephala group), mustard green (B. juncea), and turnip green (B. rapa) are the most commonly planted members of the brassica leafy greens group. In the last 10 years, numerous occurrences of bacterial blight on these leafy vegetables have been reported in several states. One of the pathogens responsible for this blight is designated Pseudomonas cannabina pv. alisalensis. Two B. rapa (G30710 and G30499) and two B. juncea (PI418956 and G30988) plant introductions (PIs) that exhibited moderate to high levels of resistance to this pathogen in greenhouse studies were tested for field resistance in comparison with eight commercial cultivar representatives of turnip green, mustard green, collard, and kale. The two B. juncea PIs and one of the B. rapa PIs (G30499) were found to have significantly less disease than all tested cultivars except 'Southern Curled Giant' mustard green (B. juncea) and 'Blue Knight' kale (B. oleracea). Inheritance of resistance studies performed with populations derived from the resistant G30988 and two susceptible PIs provided some evidence that resistance may be controlled by a single recessive gene.

Lack of association between asymmetric dimethylarginine and in vivo microvascular and macrovascular endothelial function in patients with rheumatoid arthritis.

OBJECTIVES: The aim of the present study was to investigate if assymetric dimethylarginine (ADMA) is increased in patients with rheumatoid arthritis (RA) compared to healthy controls and to examine associations between ADMA, RA disease activity and in vivo assessments of microvascular and macrovascular endothelial function. METHODS: Sixty-seven RA patients (age [mean ± standard deviation]: 56 ± 12 years, disease duration median [25th-75th percentile]: 8 [3-15] years, 48 women) and 29 healthy controls (age [mean ± standard deviation]: 42 ± 12, 21 women) underwent assessments of microvascular endothelial function (Laser Doppler imaging with iontophoresis of acetylcholine and sodium-nitroprusside), and macrovascular endothelial function (flow-mediated dilatation and glyceryl-trinitrate-mediated dilatation) as well as arterial stiffness. ADMA levels were measured in contemporary specimens using an immunoassay ELISA kit. RESULTS: ADMA levels were significantly higher (p=0.004) in RA patients compared with healthy controls after adjustment for age (difference=0.088, 95% confidence interval 0.029-0.147). ADMA levels did not correlate with demographic or disease characteristics. No correlation was found between ADMA and microvascular and macrovascular endothelial function or with arterial stiffness. CONCLUSIONS: ADMA levels are increased in patients with RA but there was no significant correlation with in vivo assessments of endothelial function. Further studies are needed to unfold the pathophysiological role of nitric oxide/ADMA pathway derangement in endothelial dysfunction and cardiovascular risk in RA.

First Report of Bacterial Leaf Blight on Broccoli and Cabbage Caused by Pseudomonas syringae pv. alisalensis in South Carolina.

In May of 2009, leaf spot and leaf blight symptoms were observed on broccoli (Brassica oleracea var. italica) and cabbage (B. oleracea var. capitata) on several farms in Lexington County, the major brassica-growing region of South Carolina. Affected areas ranged from scattered disease foci within fields to entire fields. Initial infection symptoms on leaves of both crops included circular and irregular-shaped necrotic lesions that were 3 to 10 mm in diameter, often with yellow halos and water soaking. As the disease progressed, the lesions tended to coalesce into a general blight of the entire leaf. Diseased leaves from both broccoli and cabbage were collected from each of four fields at different locations in the county. Leaves were surface disinfested, macerated in sterile distilled water, then aliquots of the suspension were spread on King's medium B (KB) agar. All samples produced large numbers of bacterial colonies that fluoresced blue under UV light after 24 h of growth. In total, 23 isolates (13 from broccoli and 10 from cabbage) were collected. These isolates were gram negative, levan production positive, oxidase negative, pectolytic activity negative, arginine dihydrolase negative, and produced a hypersensitive response on tobacco, thus placing them in the Pseudomonas syringae LOPAT group (2). Two broccoli and two cabbage isolates were selected at random and tested for pathogenicity to cabbage cv. Early Jersey Wakefield, broccoli cv. Decicco, turnip cv. Topper, broccoli raab cv. Spring, collard cv. Hi-Crop, and oat cv. Montezuma in greenhouse tests. Bacteria were grown on KB agar for 24 h and a bacterial suspension was prepared and adjusted to an optical density of 0.1 at 600 nm. Three-week-old plants were spray inoculated to runoff and held at 100% relative humidity for 12 h after inoculation, prior to return to the greenhouse bench (4). P. syringae pv. maculicola strain F18 (4) and the pathotype strain of P. syringae pv. alisalensis BS91 were included as controls, along with a water-inoculated negative control. Plants were evaluated at 14 days postinoculation. The four unknown bacterial isolates and BS91 were pathogenic on all brassica plants tested, as well as on oat. In contrast, the P. syringae pv. maculicola strain F18 was not pathogenic on broccoli raab or oat. Symptoms produced by all isolates and strains tested were similar to those observed in the field. No symptoms were observed on water-inoculated plants. Comparative repetitive sequence-based (rep)-PCR DNA analysis using the BOXA1R primer (3) resulted in a DNA banding pattern of each of the isolates from the South Carolina fields (23 isolates), as well as those reisolated from inoculated plants, that was identical to P. syringae pv. alisalensis BS91 and differed from the P. syringae pv. maculicola F18 strain. On the basis of the rep-PCR assays and the differential host range (1), the current disease outbreak on broccoli and cabbage in South Carolina is caused by the bacterium P. syringae pv. alisalensis. Broccoli is a relatively new, albeit rapidly expanding, production vegetable in South Carolina; this disease may represent a limiting factor to future production. References: (1) N. A. Cintas et al. Plant Dis. 86:992, 2002. (2) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (3) J. Versalovic et al. Methods Mol. Cell. Biol. 5:25, 1994. (4) Y. F. Zhao et al. Plant Dis. 84:1015, 2000.

What predicts obesity in patients with rheumatoid arthritis? An investigation of the interactions between lifestyle and inflammation.

OBJECTIVE: To assess whether physical activity, diet or inflammation is a more important determinant of body mass index (BMI) and body fat (BF) in patients with rheumatoid arthritis (RA). METHODS: A total of 150 RA patients (102 female) were assessed for BMI and BF. Their habitual physical activity was assessed with the international physical activity questionnaire (IPAQ) and their energy intake with a 3-day food diary. Pro-inflammatory cytokines (interleukins, IL-1 and IL-6, and tumor necrosis factor-alpha), erythrocyte sedimentation rate, C-reactive protein, disease activity score-28 and physical function (Health Assessment Questionnaire-HAQ) were also measured. RESULTS: BMI correlated inversely with IPAQ (r=-0.511, P=0.000) and positively with energy intake (r=0.331, P=0.016) and HAQ (r=0.133, P=0.042). BF correlated inversely with IPAQ (r=-0.575, P=0.000) and positively with HAQ (r=0.201, P=0.037). Normal weight patients were more physically active compared with those who were either overweight (P=0.006) or obese (P=0.000). Underweight patients consumed significantly fewer calories compared with other patients (P<0.05 in all cases). Cytokines or HAQ did not differ between weight groups. IPAQ was the sole predictor of obesity, whereas energy intake was the sole predictor of underweight. CONCLUSIONS: Inflammation does not seem to influence BMI and BF in RA. As in the general population, high levels of habitual physical activity associate with low BMI and BF in RA. Energy intake is a major determinant of being underweight in those who consume fewer calories. Further research is needed to investigate the suitability of exercise and diet modalities, and their effects on the body composition of RA patients.

Transforming growth factor-beta1 869T/C, but not interleukin-6 -174G/C, polymorphism associates with hypertension in rheumatoid arthritis.

OBJECTIVES: Part of the deleterious effects of systemic inflammation on the cardiovascular system of patients with RA may be exerted via increased propensity to hypertension. IL-6 and TGF-beta1 are important regulators of the inflammatory response. In some, but not all, studies, IL6 -174G/C (rs1800795) and TGFB1 869T/C (rs1982073) gene polymorphisms have been associated with hypertension in the general population. The present study addressed their potential association with hypertension in RA patients. METHODS: TGFB1 869T/C and IL6 -174G/C were identified in 400 RA patients and 422 local, non-RA controls using real-time PCR and melting curve analysis. Binary logistic and linear regression models were used to identify the independence of the effects of the polymorphisms on hypertension. RESULTS: Genotypic and allelic frequencies of the two polymorphisms were similar in RA and controls. Within the RA group, there was no significant association between IL6 -174G/C and hypertension, but TGF 869T-allele carriers had significantly increased prevalence of hypertension compared with CC homozygotes (70.2 vs 55.2%; P = 0.023). This association remained significant after adjustment for other hypertension risk factors and medication (odds ratio = 1.96; 95% CI 1.02, 3.77; P = 0.044), and was more pronounced in patients with increased systemic inflammation. CONCLUSIONS: This study suggests an association of TGFB1 869T/C, but not of IL6 -174G/C, with hypertension in RA patients. If this finding is confirmed in prospective studies, this polymorphism could be used as a screening tool for RA patients with higher risk of developing hypertension and lead to increased surveillance and earlier treatment.

Lymphotoxin 252A>G polymorphism is common and associates with myocardial infarction in patients with rheumatoid arthritis.

OBJECTIVE: Cardiovascular disease (CVD) is more prevalent and more likely to lead to death in patients with rheumatoid arthritis (RA). Single nucleotide polymorphisms of the genes for lymphotoxin-A (LT-A) and its regulatory protein galectin-2 (LGALS2) have been implicated as genetic risk factors for acute cardiovascular events in the general population: we hypothesised that their risk alleles/genotypes (a) may be more frequent among patients with RA compared with non-RA controls (thus explaining some of the increased CVD in RA), and (b) may be more frequent among patients with RA with prevalent CVD compared with patients with RA without CVD. METHODS: Genomic DNA samples were collected from 388 patients with RA and 399 local population controls without RA. LT-A gene intron 1 252A>G and LGALS2 intron 1 3279C>T single nucleotide polymorphisms were identified using real-time polymerase chain reaction and melting curve analysis. RESULTS: LT-A 252GG homozygotes were significantly more prevalent among patients with RA compared with controls (19.8% vs 11.8%, p = 0.002; OR(GG/GA,AA) = 1.85, 95% CI 1.25 to 2.75, p = 0.002). Patients with RA possessing LT-A 252 GG were significantly more likely to have had a myocardial infarction compared with those with LT-A 252 AA or GA (13% vs 5.5%, p = 0.02; adjusted OR(GG/GA,AA) = 3.03, 95% CI 1.2 to 7.68, p = 0.002). The frequency of LGALS2 polymorphisms was similar between RA and controls and was not associated with CVD among patients with RA. CONCLUSIONS: The LT-A 252GG genotype occurs more frequently among patients with RA than the general population. In RA, this genotype appears to associate with increased likelihood of suffering an myocardial infarction.

First Report of Severe Outbreaks of Bacterial Leaf Spot of Leafy Brassica Greens Caused by Xanthomonas campestris pv. campestris in South Carolina.

Severe outbreaks of leaf spot disease of leafy vegetable brassica crops have occurred from early spring to late fall for at least the past 7 years in Lexington County, South Carolina, the major growing region for leafy greens in the state. Significant economic losses to this disease totaling $1.7 million have been incurred by large and small growers. In 2005, Pseudomonas syringae pv. maculicola was reported as one of the causal organisms of leaf spot disease in South Carolina (2). Investigations during 2006 and 2007 have led to the isolation of another bacterium causing leaf spotting of brassica crops. Symptoms in the field were nearly identical to symptoms caused by P syringae pv. maculicola, i.e., small, brown necrotic spots, often with chlorotic halos that expand and coalesce to cover the leaves. Colonies recovered from diseased tissues were xanthomonad like, nonfluorescent on Pseudomonas Agar F, mucoid on yeast extract dextrose chalk medium, grew at 35°C, hydrolyzed starch, positive for protein digestion, alkaline in litmus milk, and produce acid from arabinose. Sequence data from the 16S rDNA and fatty acid methyl ester analysis gave the best homology to Xanthomonas campestris pv. campestris with a similarity score index of >0.98 and >0.70, respectively, confirming genus and species. Excised-cotyledon assays, used to differentiate between pathovars campestris and armoraciae, confirmed the pathovar as campestris (1). Pathogenicity assays with spray inoculations (1 × 107 CFU/ml) (3) on eight plants each of 'Topper' and 'Alamo' turnip, 'Early Jersey Wakefield' cabbage, and 'Money maker' tomato produced leaf-spot symptoms within 10 days in the greenhouse and growth chamber on the turnip and cabbage plants, but not the tomato. X. campestris pv. campestris, which is common throughout the world, also is the causal agent of black rot in brassica. Typical black rot symptoms are seen often in Lexington County fields in summer and are quite different from the leaf spot symptoms observed. Leaf-spotting X. campestris pv. campestris (LS) strains and black rot (BR) strains, recovered from black rot-symptomatic plants lacking leaf spots, from the same fields were compared in greenhouse pathogenicity assays on six plants each of 'Topper' turnip and 'Early Jersey Wakefield' cabbage. Spray inoculations with 20 individual LS strains and 10 individual BR strains, collected from 2005 to 2007, produced symptoms unique to each group. These symptoms included chlorotic 'V'-shaped lesions initiating from the leaf margins with black veining when plants were inoculated with BR strains, versus rapid and severe leaf spotting followed by chlorotic 'V'-shaped lesions typically lacking black-veining 10 to 16 days postinoculation associated with LS strains. Additional inoculation tests gave similar results. To our knowledge, this is the first report of a severe leaf spotting disease of field-grown brassica leafy greens caused by X. campestris pv. campestris in South Carolina. These findings may have importance in differentiation of bacterial leaf spot pathogens in brassica crops. References: (1) A. M. Alvarez et al. Phytopathology 84:1449, 1994. (2) A. P. Keinath et al. Plant Dis. 90:683, 2006. (3) W. P. Wechter et al. Hortic Sci. 42:1140, 2007.

First Report of Bacterial Leaf Spot on Leafy Brassica Greens Caused by Pseudomonas syringae pv. maculicola in South Carolina.

As of 2001, South Carolina ranked second in the United States in acreage of turnip greens (Brassica rapa) and collard (B. oleracea) and third in acreage of mustard (B. juncea). In June 2001, a leaf disease was found on turnip greens (cv. Alamo), mustard (cvs. Southern Giant Curled and Florida Broadleaf), and rape salad greens (B. napus var. napus cv. Essex) on a commercial farm in Lexington County, South Carolina. Symptoms appeared after a heavy rainstorm that included blowing sand. The disease was found in May and June 2002 on three additional farms in the same county on turnip greens cv. Topper and Royal Crown and collard cv. Top Bunch. Symptoms included small tan spots, water soaking, yellowing, and brown necrosis of leaves after spots coalesced on the lower halves of plants. Yellowing was more prevalent on older than on younger leaves. Leaf samples were collected in 2001 and 2002 from the affected hosts on the four farms. Bacterial streaming was evident from these samples and 27 strains were isolated on nutrient agar or King's medium B (KMB). All strains were gram negative and fluoresced bluegreen or yellow under UV light after 48-h growth at 28°C on Pseudomonas agar F (PAF). On the basis of LOPAT tests, the strains were identified as P. syringae (2). All 27 strains were tested for pathogenicity to rape salad greens cv. Essex and then to turnip greens cv. Topper. Plants were grown in peat-vermiculite potting mix in 10-cm-diameter pots in a greenhouse. P. syringae pv. maculicola F41, isolated from turnip in Oklahoma, and P. syringae pv. tomato F33, isolated from tomato in Oklahoma, were included as positive and negative controls along with a noninoculated control. Bacteria were grown on KMB for 48 h at 24°C, and bacterial suspensions were prepared and adjusted to 0.1 optical density at 600 nm. Three-week-old plants were held at 95 to 100% relative humidity (RH) for 48 h before they were sprayed just to runoff with inoculum and then held at 95 to 100% RH for 48 h after inoculation (4). After an additional 5 to 8 days in a greenhouse, nine strains and F41 caused symptoms on both Topper and Essex similar to symptoms observed in the field. No symptoms were observed on noninoculated plants or plants inoculated with F33. On the basis of repetitive sequence-based polymerase chain reactions with the BOXA1R primer, the DNA fingerprint of each of the nine pathogenic strains from South Carolina was nearly identical to that of F41. Bacteria isolated from inoculated, symptomatic turnip leaves had identical LOPAT and BOXA1R profiles to the corresponding original strains. Pathogenic strains had bluegreen fluorescence on PAF, whereas nonpathogenic strains fluoresced yellow. Five pathogenic strains, as well as F41, were further identified to species and pathovar with fatty acid methyl ester profiles as P. syringae pv. maculicola. To our knowledge, this is the first report of P. syringae pv. maculicola from South Carolina. Over the past 10 years, P. syringae pv. maculicola has been found in Oklahoma (4), California (1), and Ohio (3). Bacterial leaf spot has occurred yearly in South Carolina since the initial outbreaks. Currently, it is the disease that causes the greatest yield losses of leafy brassica greens in the state. References: (1) N. A. Cintas et al. Plant Dis. 85:1207, 2001. (2) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (3) M. L. Lewis Ivey et al. Plant Dis. 86:186, 2002. (4) Y. F. Zhao et al. Plant Dis. 84:1015, 2000.

Use of mineral magnetic concentration data as a particle size proxy: a case study using marine, estuarine and fluvial sediments in the Carmarthen Bay area, South Wales, U.K.

Compositional (non-magnetic) data can correlate strongly with particle size, which deems it appropriate as a particle size proxy and, therefore, a reliable means of normalising analytical data for particle size effects. Previous studies suggest magnetic concentration parameters represent an alternative means of normalising for these effects and, given the speed, low-cost and sensitivity of the measurements may, therefore, offer some advantages over other compositional signals. In this work, contemporary sediments from a range of depositional environments have been analysed with regard to their mineral magnetic concentration and textural characteristics, to observe if the strength and nature of the relationship identified in previous studies is universal. Our data shows magnetic parameters (chi(LF), chi(ARM) and SIRM) possess contrasting relationships with standard textural parameters for sediment samples collected from marine (Carmarthen Bay), estuarine (Gwendraeth Estuary) and fluvial (Rivers Gwendraeth Fach and Gwendraeth Fawr) settings. Magnetic concentrations of sediments from both the marine and estuarine environments are highly influenced by the magnetic contribution of finer particle sizes; Gwendraeth Fawr River sediments are influenced by the magnetic contribution of coarser particle sizes, while sediments from the Gwendraeth Fach River are not influenced significantly by any variations in textural properties. These results indicate mineral magnetic measurements have considerable potential as a particle size proxy for particular sedimentary environments, which in certain instances could be useful for geochemical, sediment transport, and sediment provenance studies. However, the data also highlight the importance of fully determining the nature of the relationship between sediment particle size and magnetic properties before applying mineral magnetic data as a particle size proxy.

Simultaneous measurement of specific serum IgG responses to five select agents.

Select Agents are defined by CDC and the USDA Animal and Plant Health Inspection Service (APHIS) as biological agents or toxins deemed a threat to public, animal, or plant health, or to animal or plant products. They are classified on the basis of their ease of dissemination, mortality/morbidity rate, and potential for social disruption. A subset of these agents includes Bacillus anthracis, Yersinia pestis, Francisella tularensis, ricin toxin (RT), and staphylococcal enterotoxin B (SEB). Infection or intoxication with these agents has been shown to elicit an antigen-specific serum IgG response. We describe a fluorescent covalent microsphere immunoassay (FCMIA) for measurement of specific IgG antibodies to seven different antigens from five different select agents; B. anthracis [protective antigen (PA) and lethal factor (LF)], Y. pestis (F1 and V antigens), F. tularensis, RT and SEB simultaneously in human B. anthracis vaccinee sera (containing anti-PA and anti-LF IgG) which had been spiked with animal specific IgG antibodies to the other select agents. Inter-assay and intra-assay coefficients of variation were 6.5 and 13.4%, respectively (N = 4). There were no significant differences (P > 0.70) between assay responses when the assays were performed individually or multiplexed. When the observed versus expected interpolated concentrations were compared, highly linear relationships were observed (r2 values from 0.981 to 0.999, P < 0.001). Minimum detectable concentrations (MDC) ranged from 0.3 ng mL(-1) (Y. pestis F1) to 300 ng mL(-1) (RT). Finally, the curves showed responses were linear for most analytes from their MDC to 125 (SEB) to 1,300 (Y. pestis F1) x their MDC. These data indicate that multiplexed FCMIA is a sensitive and accurate method for simultaneous measurement of specific IgG in serum to CDC select agents and may be of value in screening either decontamination workers or the general population for exposure to/infection with these agents.

Behavioral response of Lygus hesperus to conspecifics and headspace volatiles of alfalfa in a Y-tube olfactometer.

The western tarnished plant bug, Lygus hesperus Knight, feeds and develops on a variety of weeds in the spring, with later generations moving to alfalfa and cotton where severe damage to reproductive structures can occur. A synthetic attractant for monitoring or mass-trapping L. hesperus, or the identification of potential attractants for natural enemies, would be useful tools for integrated pest management programs. Studies investigated the response of naive and experienced fifth-instar and adult L. hesperus to odors associated with conspecifics and alfalfa, Medicago sativa L. Fifth-instar L. hesperus responded to all plant/insect combinations, whereas female L. hesperus only responded preferentially to vegetative and flowering alfalfa where conspecifics had fed for 24-72 hr, and to vegetative alfalfa where conspecifics were added approximately 30 min before the test began. Males were not attracted to headspace volatiles from any of the alfalfa treatments. Analysis of headspace volatiles showed that (E)-2-hexanal, (Z)-3-hexen-l-ol, alpha-pinene, (Z)-3-hexenyl acetate, (E)-2-hexenyl acetate, limonene, (Z)-ocimene, (E)-beta-ocimene, linalool, (3E)-4,8-dimethyl-1,3,7-nonatriene, and (E, E)-alpha-farnesene are emitted from both vegetative and flowering alfalfa. Indole and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were only detected in flowering alfalfa. Damage to alfalfa by L. hesperus increased emissions of (Z)-ocimene, (E)-beta-ocimene, (E)-beta-caryophyllene, and (E, E)-alpha-farnesene, while beta-pinene, myrcene, methyl salicylate, and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were only detected from damaged plants. Thus, individual or mixtures of these alfalfa volatiles may be useful as attractants for capturing nymphs and adult females of L. hesperus in the field.