Peronosporaceae species causing downy mildew diseases of Poaceae, including nomenclature revisions and diagnostic resources.

Downy mildew pathogens of graminicolous hosts (Poaceae) are members of eight morphologically and phylogenetically distinct genera in the Peronosporaceae (Oomycota, Peronosporales). Graminicolous downy mildews (GDMs) cause severe losses in crops such as maize, millets, sorghum, and sugarcane in many parts of the world, especially in tropical climates. In countries where the most destructive GDMs are not endemic, these organisms are often designated as high-risk foreign pathogens and subject to oversight and quarantine by regulatory officials. Thus, there is a need to reliably and accurately identify the causal organisms. This paper provides an overview of the Peronosporaceae species causing graminicolous downy mildew diseases, with a description of their impact on agriculture and the environment, along with brief summaries of the nomenclatural and taxonomic issues surrounding these taxa. Key diagnostic characters are summarized, including DNA sequence data for types and/or voucher specimens, morphological features, and new illustrations. New sequence data for cox2 and 28S rDNA markers are provided from the type specimens of three species, Peronosclerospora philippinensis, Sclerospora iseilematis, and Sclerospora northii. Thirty-nine species of graminicolous downy mildews are accepted, and seven previously invalidly published taxa are validated. Fifty-five specimens are formally designated as types, including lectotypification of 10 species, neotypification of three species, and holotype designation for Sclerophthora cryophila. Citation: Crouch JA, Davis WJ, Shishkoff N, Castroagudín VL, Martin F, Michelmore R, Thines M (2022). Peronosporaceae species causing downy mildew diseases of Poaceae, including nomenclature revisions and diagnostic resources. Fungal Systematics and Evolution 9: 43-86. doi: 10.3114/fuse.2022.09.05.

First Report of Impatiens Downy Mildew Outbreaks Caused by Plasmopara obducens Throughout the Hawai'ian Islands.

Downy mildew of impatiens (Impatiens walleriana Hook.f.) was first reported from the continental United States in 2004. In 2011 to 2012, severe and widespread outbreaks were documented across the United States mainland, resulting in considerable economic losses. On May 5, 2013, downy mildew disease symptoms were observed from I. walleriana 'Super Elfin' at a retail nursery in Mililani, on the Hawai'ian island of Oahu. Throughout May and June 2013, additional sightings of the disease were documented from the islands of Oahu, Kauai, Maui, and Hawai'i from nurseries, home gardens, and botanical park and landscape plantings. Symptoms of infected plants initially showed downward leaf curl, followed by a stippled chlorotic appearance on the adaxial leaf surfaces. Abaxial leaf surfaces were covered with a layer of white mycelia. Affected plants exhibited defoliation, flower drop, and stem rot as the disease progressed. Based on morphological and molecular data, the organism was identified as Plasmopara obducens (J. Schröt.) J. Schröt. Microscopic observation disclosed coenocytic mycelium and hyaline, thin-walled, tree-like (monopodial branches), straight, 94.0 to 300.0 × 3.2 to 10.8 µm sporangiophores. Ovoid, hyaline sporangia measuring 11.0 to 14.6 × 12.2 to 16.2 (average 13.2 × 14.7) µm were borne on sterigma tips of rigid branchlets (8.0 to 15.0 µm) at right angle to the main axis of the sporangiophores (1,3). Molecular identification of the pathogen was conducted by removing hyphae from the surface of three heavily infected leaves using sterile tweezers, then extracting DNA using the QIAGEN Plant DNA kit (QIAGEN, Gaithersburg, MD). The nuclear rDNA internal transcribed spacer was sequenced from each of the three samples bidirectionally from Illustra EXOStar (GE Healthcare, Piscataway, NJ) purified amplicon generated from primers ITS1-O and LR-0R (4). Resultant sequences (GenBank KF366378 to 80) shared 99 to 100% nucleotide identity with P. obducens accession DQ665666 (4). A voucher specimen (BPI892676) was deposited in the U.S. National Fungus Collections, Beltsville, MD. Pathogenicity tests were performed by spraying 6-week-old impatiens plants (I. walleriana var. Super Elfin) grown singly in 4-inch pots with a suspension of 1 × 104 P. obducens sporangia/ml until runoff using a handheld atomizer. Control plants were sprayed with distilled water. The plants were kept in high humidity by covering with black plastic bags for 48 h at 20°C, and then maintained in the greenhouse (night/day temperature of 20/24°C). The first symptoms (downward curling and chlorotic stippling of leaves) and sporulation of the pathogen on under-leaf surfaces of the inoculated plants appeared at 10 days and 21 days after inoculation, respectively. Control plants remained healthy. Morphological features and measurements matched those of the original inoculum, thus fulfilling Koch's postulates. To our knowledge, this is the first report of downy mildew on I. walleriana in Hawai'i (2). The disease appears to be widespread throughout the islands and is likely to cause considerable losses in Hawai'ian landscapes and production settings. References: (1) O. Constantinescu. Mycologia 83:473, 1991. (2) D. F. Farr and A. Y. Rossman. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ July 16, 2013. (3) P. A. Saccardo. Syllogue Fungorum 7:242, 1888. (4) M. Thines. Fungal Genet Biol 44:199, 2007.

First Report of Boxwood Blight Caused by Calonectria pseudonaviculata in Delaware, Maryland, New Jersey, and New York.

Boxwood (Buxus spp.) are commercially important evergreen ornamental plants with an annual market value of over $103 million in the United States. The recent U.S. incursion of boxwood blight disease caused by the fungus Calonectria pseudonaviculata (syn. Cylindrocladium pseudonaviculatum, Cy. buxicola) threatens the health and productivity of boxwood in both landscape plantings and nurseries. The first confirmed U.S. reports of the disease were made from Connecticut and North Carolina in November 2011 (2,4), followed by diagnoses in 10 additional states during 2012 and 2013. By August 2013, symptoms consistent with boxwood blight had been observed from B. sempervirens in Delaware, Maryland, New Jersey, and southeastern New York. Affected plants showed rapid onset of disease symptoms: dark brown to black spots or diffuse dark areas on leaves, followed by defoliation. Narrow, elongate black cankers also formed on current season shoots. Symptomatic stems and leaves were placed in petri dishes with moistened filter paper at 22°C for 3 days under continuous light. Conidiophores were excised, then placed on potato dextrose agar amended with streptomycin and neomycin (0.3 g/l). Resultant colonies showed dark brown pigmentation at the colony center surrounded by tan to reddish brown rings with white mycelia at the advancing edge. Conidia (n = 30 per isolate) were hyaline, cylindrical, rounded at both ends, with a single septum (45 to 76 × 4 to 6 µm; avg. 63 × 5 µm). Conidiophores (n = 20 per isolate) comprised a stipe, a hyaline septate stipe extension (length 119 to 192 µm; avg. 150 µm) and a terminal ellipsoidal vesicle (diameter 4 to 10 µm; avg. 7 µm). Based on morphological characteristics, the causal agent was identified as C. pseudonaviculata (1,4). Voucher specimens were deposited in the U.S. National Fungus Collections (BPI 892698 to 701). To verify morphological diagnosis, genomic DNA was extracted from fungal biomass grown in liquid cultures of yeast extract peptone dextrose media. A portion of the ß-tubulin gene (TUB2) was PCR amplified and sequenced bi-directionally using primers Bta/Bt2b (3). BLASTn searches of NCBI GenBank databases using the TUB2 sequences (Accession Nos. KF785808 to 11) demonstrated 96 to 100% sequence identity with other C. pseudonaviculata isolates. To confirm pathogenicity, 5-month-old B. sempervirens and B. microphylla seedlings were spray-inoculated with a spore suspension of 1 × 104 conidia/ml. One isolate from each state was independently tested with four replicates each. Non-inoculated water-sprayed plants served as negative controls. Plants were maintained in growth chambers at 22°C under constant light. Blight symptoms developed 4 to 5 days post inoculation. C. pseudonaviculata was re-isolated from inoculated plants; no symptoms or signs were observed from control plants. To our knowledge, this is the first report of C. pseudonaviculata in the states of Delaware, Maryland, New Jersey, and New York. This report demonstrates that C. pseudonaviculata is now widespread across the United States eastern seaboard, and represents a substantial threat to boxwood plants in North American landscapes and nurseries. References: (1) P. Crous et al. Sydowia 54:23, 2002. (2) D. F. Farr and A. Y. Rossman. Fungal Databases, USDA-ARS. Retrieved from http://nt.ars-grin.gov/fungaldatabases , 30 August 2013. (3) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (4) K. L. Ivors et al. Plant Dis. 96:1070, 2012.

First Report of Downy Mildew Caused by Plasmopara halstedii on Black-eyed Susan (Rudbeckia fulgida cv. 'Goldsturm') in Maryland.

The North American perennial black-eyed Susan (Rudbeckia fulgida cv. Goldsturm) is an important nursery crop, prized by gardeners and landscapers for its persistent bloom and ease of cultivation. In September 2013, disease symptoms characteristic of downy mildew were observed from multiple R. fulgida plants at two commercial nurseries in the Maryland counties of Howard and Anne Arundel. Over 100 R. fulgida were affected by this disease in both nurseries, rendering the plants unmarketable and causing a substantial financial loss. Plants exhibited dark necrotic lesions on the adaxial leaf surface, and sporulating masses of white mycelium on the abaxial leaf surface and on the adaxial in extreme infections. Plants were stunted with a reduced number of blooms. Microscopic visualization showed coenocytic mycelium, hyaline sporangiophores (length 261 to 904 µm; = 557 µm; n = 20) that were straight and monopodially branched at right angles with several terminal branchlets. Sporangia were hyaline, ovoid to elliptical with smooth surfaces ( = 31 × 28 µm; n = 50). Based on morphological data, the organism was identified as Plasmopara halstedii (Farl.) Berl. & De Toni in Sacc (2). Voucher specimens were deposited in the U.S. National Fungus Collections (BPI 892792 to 892794). Molecular identification was conducted by extracting genomic DNA from sporangiophores and mycelium tweezed from the surface of three infected plants, with extractions performed using the QIAGEN Plant DNA kit (QIAGEN, Gaithersburg, MD). The large subunit of the nuclear rDNA was amplified by PCR using primers LROR and LR7 (3) and sequenced bidirectionally. BLASTn searches of NCBI GenBank showed that the resultant rDNA sequences (accessions KF927152 to KF927154) shared 99% nucleotide identity with curated P. halstedii sequences, consistent with morphological identification. To confirm pathogenicity, three 3.78-liter (1 gallon) containerized R. fulgida cv. Goldsturm plants were inoculated with a sporangial suspension of 2.4 × 104 sporangia/ml and sprayed until both the upper and lower surface of the leaves were completely covered. One negative control plant was sprayed with deionized water. Plants were placed in clear plastic bags in a growth chamber (20°C, 12-h photoperiod). Disease symptoms were observed 3 days post inoculation on all plants. The control plant was symptomless. Morphological features of the pathogen on the surface of inoculated plants were identical to those observed from the original infected plants. Although P. halstedii on R. fulgida cv. Goldsturm has been previously reported in Virginia in 2006 and Florida in 2004, to our knowledge, this is the first report on R. fulgida cv. Goldsturm in Maryland (1). Black-eyed Susans are widely distributed throughout Maryland's landscape and are a staple plant for gardeners, nurserymen and landscape professionals. Given the destructive nature of this disease, downy mildew has the potential to cause considerable economic losses to the state's ornamental crop industry. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Syst. Mycol. Microbiol. Lab., ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , November 18, 2013. (2) P. A. Saccardo. Syllogue Fungorum 7:242, 1888. (3) R. Vilgalys and M. Hester. J. Bacteriol. 172:4238, 1990.

Encapsulation of Au Nanoparticles on a Silicon Wafer During Thermal Oxidation.

We report the behavior of Au nanoparticles anchored onto a Si(111) substrate and the evolution of the combined structure with annealing and oxidation. Au nanoparticles, formed by annealing a Au film, appear to "float" upon a growing layer of SiO2 during oxidation at high temperature, yet they also tend to become partially encapsulated by the growing silica layers. It is proposed that this occurs largely because of the differential growth rates of the silica layer on the silicon substrate between the particles and below the particles due to limited access of oxygen to the latter. This in turn is due to a combination of blockage of oxygen adsorption by the Au and limited oxygen diffusion under the gold. We think that such behavior is likely to be seen for other metal-semiconductor systems.

New microsatellite markers for pigeonpea (cajanus cajan (L.) millsp.).

BACKGROUND: Pigeonpea is a nutritious tropical legume with several desirable characteristics but has been relatively neglected in terms of research. More efficient improvement can be achieved in this crop through molecular breeding but adequate molecular markers are lacking and no linkage map has been developed so far. Microsatellites remain the markers of choice due to their high polymorphism and their transferability from closely related genera. The overall objective of this study was to develop microsatellite markers from an enriched library of pigeonpea as well as testing the transferability of soybean microsatellites in pigeonpea. RESULTS: Primers were designed for 113 pigeonpea genomic SSRs, 73 of which amplified interpretable bands. Thirty-five of the primers revealed polymorphism among 24 pigeonpea breeding lines. The number of alleles detected ranged from 2 to 6 with a total of 110 alleles and an average of 3.1 alleles per locus. GT/CA and GAA class of repeats were the most abundant di-nucleotide and tri-nucleotide repeats respectively. Additionally, 220 soybean primers were tested in pigeonpea, 39 of which amplified interpretable bands. CONCLUSION: Despite the observed morphological diversity, there is little genetic diversity within cultivated pigeonpea as revealed by the developed microsatellites. Although some of the tested soybean microsatellites may be transferable to pigeonpea, lack of useful polymorphism may hinder their full use. A robust set of markers will still have to be developed for pigeonpea genome if molecular breeding is to be achieved.

First Report of Anthracnose Disease of Ornamental Feather Reed Grass (Calamagrostis × acutifolia 'Karl Foerster') Caused by Colletotrichum cereale.

Calamagrostis × acutifolia 'Karl Foerster' (feather reed grass) is a cool-season grass grown extensively as an ornamental plant throughout the United States. In July 2005, severe foliar damage was observed in feather reed grasses in a residential garden in Barrington, NJ. Symptoms were observed as small, yellowish brown, oval to irregularly shaped spots on the blades, with spread and coalescence of spots leading to eventual necrosis and plant death. Numerous acervuli with black setae diagnostic of fungi in the genus Colletotrichum were present on necrotic lesions. Two distinct fungi were isolated from diseased tissue by plating small sections of infested leaf tissue on potato dextrose agar (PDA) supplemented with 40 µg/liter each of penicillin, ampicillin, gentomycin, and streptomycin. The first fungus was identified as Colletotrichum gloeosporioides based on morphological, cultural (2), and molecular characteristics. Variable colonies of gray-white mycelia with masses of pink-to-salmon hued conidia formed at 25°C on PDA under constant light. Conidia were hyaline, aseptate, straight, and cylindrical with rounded apices (11.0 to 18.5 × 2.5 to 5.0 µm). Sequencing of the internal transcribed spacer (ITS) rDNA region showed the fungus to be most similar to C. gloeosporioides (GenBank Accession No. EU979125). The second fungus was identified as C. cereale based on morphological, cultural, and molecular characteristics (1). Variable colonies of gray-tan-white mycelia formed at 25°C on PDA under constant light and salmon-colored conidial masses surrounded numerous setae. Conidia were hyaline, aseptate, falcate, fusiform, and guttulate (15.0 to 21.5 × 2.5 to 4.5 µm). Hyphal appressoria were ovoid, sometimes lobate or multilobate (10.5 to 13.5 × 7.5 to 10.0 µm). Maximum likelihood phylogenetic analysis of the ITS sequence (GenBank Accession No. DQ126193) and fungal mating type idiomorph Mat1-2 HMG box (GenBank Accession No. DQ131962) identified the fungus as C. cereale (1). Pathogenicity was determined by inoculating healthy feather reed grasses (11.4-liter pots) established 61 cm off-center in a mulched bed. Three replicate plants per treatment were sprayed with a 20-ml conidial solution (5 × 104 conidia/ml in 0.1 potato dextrose broth) of either C. cereale or C. gloeosporioides and an uninoculated control. Temperatures ranged from 19 to 36°C and humidity varied between 31 and 79%. No symptoms were observed in uninoculated controls or plants inoculated with C. gloeosporioides. Plants inoculated with C. cereale developed disease symptoms within 21 days; the fungus was subsequently reisolated from symptomatic leaves and confirmed as C. cereale. To our knowledge, this is the first report of anthracnose of feather reed grass caused by C. cereale (formerly known as C. graminicola). Although C. cereale is known to inhabit numerous cool-season grass hosts, this is the first description of this fungus as a pathogen of an ornamental grass. Given the recent emergence of anthracnose epidemics caused by C. cereale on golf course turfgrass, the identification of this fungus as a pathogen of Calamagrostis × acutifolia highlights the need for nurseries and regulatory personnel to screen ornamental grasses such as feather reed grass for the presence of C. cereale so that the disease does not become problematic. References: (1) J. A. Crouch et al. Phytopathology 96:46, 2006. (2) B. C. Sutton. The genus Glomerella and its anamorph Colletotrichum in: Colletotrichum: Biology, Pathology and Control. J. A. Bailey and M. J. Jeger, eds. CAB International, Wallingford, UK, 1992.

Tract-based spatial statistics of diffusion tensor imaging in adults with dyslexia.

BACKGROUND AND PURPOSE: Diffusion tensor imaging is a tool that can be used to study white matter microstructure in dyslexia. We tested the hypothesis that dyslexics have a white matter structural change (as measured by directional diffusion of water, which can be affected by disruption in white matter tracts) between brain regions that previous functional connectivity studies showed were associated with phonologic processing. MATERIALS AND METHODS: Diffusion tensor imaging (DTI) scans were acquired from 7 healthy adult normal readers and from 14 adults with dyslexia on a 1.5T scanner. Voxelwise statistical analysis of the fractional anisotropy data were carried out by using Tract-Based Spatial Statistics to compare dyslexic subjects versus control subjects in white matter tracts. RESULTS: Significant group difference map clusters (comparing adults with and without dyslexia) occurred in specific bilateral white matter tracts within the frontal lobe, temporal lobe, occipital lobe, and parietal lobe. CONCLUSION: The DTI fractional anisotropy results in the bilateral white matter showing higher fractional anisotropy in adult control subjects compared with adults with dyslexia (relating to white matter fiber tract integrity) are consistent with our previous functional connectivity results from seed points in the bilateral inferior frontal gyrus.

First Report of Colletotrichum cereale Causing Anthracnose Foliar Blight of Creeping Bentgrass in Mississippi and Alabama.

Colletotrichum cereale Manns, formerly C. graminicola (Ces.) G.W. Wils., is the causal agent of anthracnose foliar blight (AFB) of creeping bentgrass (Agrostis stolonifera L.) and other grass species (1). AFB is most prevalent on creeping bentgrass during summer heat stress (2). Symptoms of AFB progress from older to younger leaves with leaf tips becoming chlorotic and eventually developing complete leaf necrosis. Symptoms in turf stands appear as yellow-to-bronze, irregularly shaped patches often associated with a loss of turf density (2). When C. cereale is actively infecting the foliar tissue, appressoria can be observed microscopically in the leaf sheaths of creeping bentgrass. C. cereale colonizes the foliar tissue, producing abundant acervuli, where conidia and setae develop. Creeping bentgrass samples exhibiting symptoms of AFB were collected from West Point, MS and Birmingham, AL in July 2006. Symptomatic plants with signs of C. cereale were surface disinfested and plated onto one-quarter-strength potato dextrose agar (PDA). Monoconidial C. cereale isolates were grown on full-strength PDA for 21 days at 25°C under fluorescent lights. Single-celled conidia were mostly falcate, ranged from 13.1 to 25.6 µm long × 3.6 to 6.3 µm wide, and averaged 22.2 × 4.7 µm. Hyphal appressoria were irregularly shaped and heavily lobed, ranging from 5.6 to 16.1 µm long × 4 to 10.6 µm wide, and averaged 12.1 × 7.9 µm. In culture, setae were acicular, five to seven septate, thick walled, ranged from 74 to 213.5 µm long, and averaged 151.3 µm. The morphological characteristics of 44 AFB isolates were similar to those of C. cereale reported by Crouch et al. (1). Nucleotide sequences were generated for the internal transcribed spacer rDNA for isolates OO7-T42, OW15-H32, and 04-111 (GenBank Accession Nos. EU859957, EU859958, and EU859959). Maximum likelihood-based phylogenetic analyses of these sequences with authentic isolates of Colletotrichum species from grass hosts (2) indicated that all three isolates were C. cereale. 'Penn A-1' creeping bentgrass seedlings (10.16-cm pots) were inoculated with the C. cereale isolates OO7-T42, OW15-H32, or 04-111 by spraying a conidial suspension (1.5 × 105 conidia/ml) on plants until water droplets were evident within the canopy. An uninoculated control sprayed with distilled water only was used for comparison. Three replicates per C. cereale isolate were included simultaneously when performing Koch's postulates. The inoculated creeping bentgrass seedlings were placed in covered plastic boxes to maintain humidity and incubated under 12 h of fluorescent light with day/night temperatures at 35/28°C. After 4 days, the covers were removed and creeping bentgrass was maintained an additional 14 days until symptoms and signs were observed on the foliage. C. cereale was reisolated from inoculated creeping bentgrass exhibiting symptoms of AFB for all three isolates used. No acervuli, setae, or conidial masses were observed on uninoculated control plants. To our knowledge, this is the first report of C. cereale causing AFB on creeping bentgrass in Mississippi and Alabama. References: (1) J. A. Crouch et al. Phytopathology 96:46, 2006. (2) R. W. Smiley et al. Compendium of Turfgrass Diseases. The American Phytopathological Society, St. Paul, MN, 2005.

Comparative assessment of genetic diversity of peanut (Arachis hypogaea L.) genotypes with various levels of resistance to bacterial wilt through SSR and AFLP analyses.

Bacterial wilt (BW) caused by Ralstonia solanacearum is an important constraint to peanut (Arachis hypogaea L.) production in several Asian and African countries, and planting BW-resistant cultivars is the most feasible method for controlling the disease. Although several BW-resistant peanut germplasm accessions have been identified, the genetic diversity among these has not been properly investigated, which has impeded efficient utilization. In this study, the genetic relationships of 31 peanut genotypes with various levels of resistance to BW were assessed based on SSR and AFLP analyses. Twenty-nine of 78 SSR primers and 32 of 126 AFLP primer combinations employed in this study were polymorphic amongst the peanut genotypes tested. The SSR primers amplified 91 polymorphic loci in total with an average of 3.14 alleles per primer, and the AFLP primers amplified 72 polymorphic loci in total with an average of 2.25 alleles per primer. Four SSR primers (14H06, 7G02, 3A8, 16C6) and one AFLP primer (P1M62) were found to be most efficient in detecting diversity. The genetic distance between pairs of genotypes ranged from 0.12 to 0.94 with an average of 0.53 in the SSR data and from 0.06 to 0.57 with an average of 0.25 in the AFLP data. The SSR-based estimates of the genetic distance were generally larger than that based on the AFLP data. The genotypes belonging to subsp. fastigiata possessed wider diversity than that of subsp. hypogaea. The clustering of genotypes based on the SSR and AFLP data were similar but the SSR clustering was more consistent with morphological classification of A. hypogaea. Optimum diverse genotypes of both subsp. hypogaea and subsp. fastigiata can be recommended based on this analysis for developing mapping populations and breeding for high yielding and resistant cultivars.

Evaporative tunnel cooling of dairy cows in the southeast. I: effect on body temperature and respiration rate.

The techniques used to mitigate the effects of heat stress on lactating dairy cows are often overwhelmed in the southeastern United States, where elevated heat and humidity often persist for extended periods. A model free-stall barn located at the North Mississippi Branch Experiment Station in Holly Springs was used to evaluate the potential of tunnel ventilation with evaporative cooling to alleviate heat stress in lactating dairy cows. Two studies were conducted using 2 groups of 10 lactating Holsteins housed in the tunnel barn (inside) and 2 groups of matched herdmates housed in an adjacent covered free-stall barn (outside), which was cooled by fans and sprinklers during 2001 or by shade and fans alone in 2003. Peak daytime temperatures inside were 5.2 +/- 0.18 degrees C below that outside in 2001 and 3.1 +/- 0.20 degrees C lower in 2003. Although evaporative cooling increased humidity by 22%, cows housed in the tunnel barn received 84% less exposure to moderate heat stress (temperature-humidity index > 80) in both years. Cooling cows with evaporative tunnel ventilation reduced respiration rates by 15.5 +/- 0.56 breaths/min and rectal temperatures by 0.6 +/- 0.02 degrees C compared with shade and fans alone in 2003. Cooling cows with evaporative tunnel ventilation reduced respiration rates by 13.1 +/- 0.78 breaths/min and rectal temperatures by 0.4 +/- 0.03 degrees C compared with fans and sprinklers in 2001. Thus, tunnel ventilation cooling dramatically reduced the exposure to heat stress and improved the comfort of lactating dairy cows when compared with traditional cooling technologies under the conditions present in the southeastern United States.

Evaporative tunnel cooling of dairy cows in the southeast. II: impact on lactation performance.

Heat stress has a dramatic impact on the dairy industry, reducing production and profitability throughout the southeastern United States. In many regions, management techniques can be used to mitigate the effects of heat stress, but available cooling technologies are often overwhelmed by the conditions of chronic heat stress present in southeastern United States. Although combining tunnel ventilation and evaporative cooling (evaporative tunnel cooling) seems to provide superior cooling for dairy cows, there is a dearth of reports on the impact of this technology on milk production. A model evaporative tunnel cooling facility in northern Mississippi was studied using 2 groups of 10 lactating Holstein cows housed in the tunnel barn and 2 groups of 10 matched herdmates housed in an adjacent naturally ventilated free-stall barn. Two 10-wk trials were performed in 2 yr beginning June 25, 2001, and May 26, 2003, in which cows housed outside were cooled by traditional fans and shade alone (2003) or with sprinklers (2001). In both years, the use of evaporative tunnel cooling decreased exposure to conditions of moderate heat stress by 84%. Cows cooled by evaporative tunnel ventilation increased feed intake by 12 and 11% over cows housed outside in 2001 and 2003, respectively. Evaporative tunnel cooling had no effect on milk composition, but increased milk yield over the 10-wk trial by 2.6 +/- 0.27 and 2.8 +/- 0.19 kg/cow per day in 2001 and 2003, respectively. In addition, somatic cell count was decreased 27 to 49% by evaporative tunnel cooling. Thus, under the range of environmental conditions present, evaporative tunnel cooling reliably reduced exposure to conditions of heat stress and improved milk production of lactating dairy cows during the summer season.

The Trauma Symptom Checklist for Young Children (TSCYC): reliability and association with abuse exposure in a multi-site study.

OBJECTIVE: The Trauma Symptom Checklist for Young Children (TSCYC) is a 90-item caretaker-report measure of children's trauma- and abuse-related symptomatology. It contains two reporter validity scales and eight clinical scales [Post-traumatic Stress-Intrusion (PTS-I), Post-traumatic Stress-Avoidance (PTS-AV), Post-traumatic Stress-Arousal (PTS-AR), Post-traumatic Stress-Total (PTS-TOT), Sexual Concerns (SC), Dissociation (DIS), Anxiety (ANX), Depression (DEP), and Anger/Aggression (ANG)], as well as an item assessing hours per week of caretaker contact with the child. This paper introduces the TSCYC and describes its psychometric properties in a multisite validity study. METHOD: A total of 219 TSCYCs administered by six clinician/researchers across the United States were analyzed for scale reliability and association with several types of childhood maltreatment. RESULTS: The TSCYC clinical scales have good reliability and are associated with exposure to childhood sexual abuse, physical abuse, and witnessing domestic violence. The PTS-I, PTS-AV, PTS-AR, and PTS-TOT scales were most predictive, followed by SC in the case of sexual abuse and DIS in the case of physical abuse. There were a small number of age, sex, and race effects on TSCYC scores. CONCLUSIONS: The TSCYC appears to have reasonable psychometric characteristics, and correlates as expected with various types of trauma exposure. Subject to continued validation and the development of general population norms, its use as a clinical measure is supported.

Relationships among parental beliefs in corporal punishment, reported stress, and physical child abuse potential.

OBJECTIVE: The present study examined the extent to which parental belief in the value of corporal punishment moderates the association between level of parenting stress and physical child abuse potential. Based on existing theory, it was expected that levels of parenting stress would be positively associated with physical child abuse potential among parents who reported high levels of belief in the value of corporal punishment. METHOD: Forty-one parents (25 general population and 16 at-risk parents) were assessed for belief in the value of corporal punishment, level of parenting stress, and physical child abuse potential using self-report measures. After removal of respondents due to response distortion or missing data, the final sample consisted of 31 parents with valid and complete protocols. Based on their responses on the study measures, respondents were categorized as either high or low on belief in corporal punishment and parenting stress. RESULTS: Level of parenting stress was positively associated with physical child abuse potential. As expected, the interaction of parenting stress and belief in the value of corporal punishment was significant. Level of parenting stress was positively associated with physical child abuse potential among parents who reported high levels of belief in the value of corporal punishment. In contrast, level of parenting stress was not associated with physical child abuse potential among parents who reported low belief in the value of corporal punishment. CONCLUSIONS: The present findings are consistent social information processing and stress and coping models of the etiology of physical child abuse, and underscore the importance of considering both parental cognitions and levels of parenting stress in assessing potential for physical child abuse.

Endocarditis caused by culture-negative organisms visible by Brown and Brenn staining: utility of PCR and DNA sequencing for diagnosis.

Two cases of culture-negative endocarditis with cocci seen in valve vegetations are presented. The organisms were identified by molecular analysis using broad-range PCR primers complementary to the 16S rRNA gene, sequencing, and database search using BLAST software. The results and utility of this method are discussed.

Platelet PlA2 polymorphism enhances risk of neurocognitive decline after cardiopulmonary bypass. Multicenter Study of Perioperative Ischemia (McSPI) Research Group.

BACKGROUND: Neurocognitive decline, often produced by atherosclerotic plaque embolization, remains a frequent complication of cardiopulmonary bypass. Plaque fragments may initiate local thrombosis, which, in turn, aggravates the embolic insult. Prothrombotic genetic factors may exacerbate this process. We investigated whether the PlA2 polymorphism of platelet GPIIIa, a prothrombotic risk factor in other cardiovascular settings, is associated with early neurocognitive decline after cardiopulmonary bypass. METHODS: Neurocognitive changes were evaluated by the Mini-Mental State Examination administered preoperatively and on postoperative day 4 and the PlA genotype determined in 70 patients undergoing cardiopulmonary bypass. RESULTS: Forty-nine patients were PlA1/A1, and 21 were PlA1/A2 or PlA2/A2. Fifty-two patients (74%) demonstrated post-cardiopulmonary bypass neurocognitive decline, of which 34 were PlA1/A1 and 18 were PlA1/A2 or PlA2/A2 Multivariate analysis revealed that the PlA2 genotype and baseline Mini-Mental State Examination were significantly associated with greater neurocognitive decline (decreased Mini-Mental State Examination scores, p = 0.036 and 0.024, respectively). CONCLUSIONS: This study demonstrates a link between the PlA2 allele of platelet GPIIIa and more severe neurocognitive decline after cardiopulmonary bypass. Although the mechanism is unknown, it could represent exacerbation of platelet-dependent thrombotic processes associated with plaque embolism.

Impact of childhood rape and aggravated assault on adult mental health.

Associations among childhood assault (rape, aggravated assault, or both) and indices of adult mental health (posttraumatic stress disorder, major depressive episode) were examined in a national probability sample of 4,008 (weighted) women. Relationships among assault characteristics and these adult mental health indices were also investigated. Findings suggested particularly deleterious effects for childhood aggravated assault and rapes that caused additional physical injury.

Childhood physical abuse, early social support, and risk for maltreatment: current social support as a mediator of risk for child physical abuse.

OBJECTIVE: The study investigated whether perceptions of social support in adulthood partially mediated the associations between childhood experiences (i.e., receipt of physical abuse and levels of early social support) and adult risk for child physical abuse. METHOD: Participants included 598 general population adults who completed self-report measures designed to assess childhood physical abuse, perceptions of early and current social support, and risk factors for child physical abuse. Structural equation modeling was used to test and cross validate a model that included the direct effects of child physical abuse and early social support on child physical abuse risk, as well as mediated effects through an influence on adult perceptions of social support. RESULTS: Childhood physical abuse and early social support covaried, such that receipt of physical abuse was associated with lower levels of perceived early social support. Early support, but not child physical abuse, had an indirect effect (i.e., through current support) on child physical abuse risk. More specifically, levels of early support were directly related to adult perceptions of support, and adult perceptions of support were inversely associated with child physical abuse risk. Childhood physical abuse was directly related to child physical abuse risk. CONCLUSIONS: Low levels of early support may impact risk for child physical abuse by affecting perceptions of others as supportive in adulthood. The receipt of physical abuse in childhood, however, does not appear to impact perceptions of support in adulthood. Research is needed to identify additional factors that may explain the association between receipt of physical abuse in childhood and increased risk of child physical abuse in adulthood.

Classification accuracy of the portland digit recognition test in traumatic brain injury.

This study examined the classification accuracy of the Portland Digit Recognition Test (PDRT) in traumatic brain injury (TBI). It differs from past studies in assigning patients to malingering and control groups on the basis of compensation-seeking status and the presence of external markers for malingering. Sensitivity and Specificity were.77 and 1.00, respectively. Past research comparing compensation-seekers to noncompensation-seekers reported Sensitivities of.33 or lower (Specificity is always high). This study demonstrates that past research has seriously underestimated the Sensitivity of the PDRT and raises questions about the true Sensitivity of other malingering techniques as well.