Evaluating the Student Training Equity Project: An Upstream Recruitment Approach to Diversifying Clinical Psychology Graduate Programs

The U.S. psychology workforce is considerably less diverse than the population that it serves. While several recruitment and admission practices are effective for diversifying psychology training programs, upstream recruitment of underrepresented candidates is particularly promising. Aiming to diversify the clinical psychology graduate program applicant pool, the Student Training Equity Project (STEP) was developed to promote and evaluate upstream recruitment of undergraduate students of color interested in psychology graduate studies. This study used a mixed-method design to evaluate immediate outcomes for three STEP programmatic strategies. Survey results suggest that STEP networking events were associated with undergraduate research and mentorship opportunities. Findings suggest that STEP funding supported students in producing research products (e.g., manuscripts) that might bolster graduate application materials. STEP website engagement data showed over 1,000 views per year, and highlighted ways to improve outreach. More controlled evaluation is needed to determine whether STEP contributed to diversification of the applicant pool

Taxonomie des streptomycétes causant la gale commune et implication de la thaxtomine A dans leur pouvoir pathogène

Les travaux visaient à caractériser les agents pathogènes qui étaient responsables de la gale commune au Québec. Les isolats de Streptomyces phytopathogènes ont été classés dans trois groupes, identifiés comme étant du S. scabies, S. acidiscabies et une espèce inconnue de Streptomyces causant la gale profonde. Dans le but de mieux caractériser les Streptomyces phytopathogènes du Québec, des études taxonomiques ont été entreprises sur les souches de S. scabies et les souches de Streptomyces causant la gale profonde. Les nombreuses souches de S. scabies ont été étudiées en utilisant plusieurs outils taxonomiques tels que les patrons en acides gras, les profils de protéines, et l'hybridation ADN-ADN. Les patrons d'acides gras et les profils de protéines montraient qu'il y avait beaucoup de diversité entre les souches de S. scabies. L'hybridation ADN-ADN a confirmé ces résultats en montrant que les souches de S. scabies isolées de la pomme de terre ou de la carotte pouvaient être classées dans au moins trois groupes génétiques différents. Les niveaux de similarité étaient beaucoup plus faibles que ceux généralement retrouvés entre les souches d'une même espèce bactérienne. Ces travaux ont montré que les souches de Streptomyces causant la gale profonde au Québec constituaient une nouvelle espèce de Streptomyces. Les souches de Streptomyces causant la gale profonde ont été comparées aux autres espèces pathogènes de Streptomyces. Les patrons d'acides gras, les profils de protéines, l'analyse numérique et l'hybridation ADN-ADN ont clairement démontré que les souches de Streptomyces causant la gale profonde avaient des caractéristiques distinctes des autres espèces de Streptomyces. Streptomyces caviscabies est le nom qui a été choisi pour cette nouvelle espèce bactérienne. Suite à la caractérisation des espèces de Streptomyces phytopathogènes retrouvées au Québec, la gamme de plantes pouvant être infectées par S. scabies, S. acidiscabies et S. caviscabies a été étudiée. Plusieurs plantes ont été incluses dans cette étude dont la betterave, la carotte, le panais, le radis, le navet et la pomme de terre. Nous avons démontré que les différentes espèces de Streptomyces n'avaient pas la même gamme de plantes hôtes. Alors que le radis, la carotte et la pomme de terre sont plus susceptibles d'être infectés, la betterave, le panais et le navet semblaient plus tolérants à l'infection. Le rôle dans la pathogénèse de la thaxtomine A, qui est produite par les Streptomyces phytopathogènes a été étudié. Les effets de la thaxtomine A sur les tissus végétaux ont été analysés. La thaxtomine A induisait une chlorose puis une nécrose sur les feuilles de betterave, de navet, de tomate, de pomme de terre et de framboisier. La thaxtomine A n'est donc pas une toxine spécifique à la pomme de terre puisqu'elle provoque des nécroses chez d'autres plantes ce qui indique que la cible de la thaxtomine est commune à plusieurs espèces végétales. Par microscopie électronique, les effets de la thaxtomine ont été étudiés sur les cellules de tubercules de pommes de terre. La thaxtomine A affectait plus particulièrement la membrane plasmique des cellules en induisant des invaginations. De plus, un matériel fibrillaire s'accumulait dans le cytoplasme des cellules et les parois se couvraient de matériel dense aux électrons. L'application de thaxtomine A entraînait la mort cellulaire. Bien que la thaxtomine A soit toxique pour les cellules végétales, l'implication de la thaxtomine A dans le pouvoir pathogène des Streptomyces phytopathogènes n'avait pas été démontrée. Des mutants de S. scabies souche EF-35 ont été créés par une mutagénèse chimique afin d'étudier leur comportement pathogénique. Six mutants affectés dans la production de thaxtomine A ont été sélectionnés. Quatre de ces mutants produisaient de 2 à 20 fois moins de thaxtomine A que la souche sauvage EF-35. Ces mutants étaient généralement moins agressifs sur le radis et la pomme de terre que la souche sauvage EF-35. Un des autres mutants produisait 355 fois moins de thaxtomine A que la souche sauvage alors que l'autre mutant n'en produisait pas une quantité détectable. Ces deux mutants n'étaient plus pathogènes sur le radis et la pomme de terre. Ces résultats démontraient que la thaxtomine A était un facteur de virulence crucial dans le pouvoir pathogène de S. scabies

Long-term induction of defense gene expression in potato by pseudomonas sp. LBUM223 and streptomyces scabies

Streptomyces scabies is a causal agent of common scab of potato, which generates necrotic tuber lesions. We have previously demonstrated that inoculation of potato plants with phenazine-1-carboxylic acid (PCA)- producing Pseudomonas sp. LBUM223 could significantly reduce common scab symptoms. In the present study, we investigated whether LBUM223 or an isogenic phzC- mutant not producing PCA could elicit an induced systemic resistance response in potato. The expression of eight defense-related genes (salicylic acid [SA]-related ChtA, PR-1b, PR-2, and PR-5; and jasmonic acid and ethylene-related LOX, PIN2, PAL-2, and ERF3) was quantified using newly developed TaqMan reverse-transcription quantitative polymerase chain reaction assays in 5- and 10-week-old potted potato plants. Although only wild-type LBUM223 was capable of significantly reducing common scab symptoms, the presence of both LBUM223 and its PCA-deficient mutant were equally able to upregulate the expression of LOX and PR-5. The presence of S. scabies overexpressed all SA-related genes. This indicates that (i) upregulation of potato defense-related genes by LBUM223 is unlikely to contribute to common scab's control and (ii) LBUM223's capacity to produce PCA is not involved in this upregulation. These results suggest that a direct interaction occurring between S. scabies and PCA-producing LBUM223 is more likely involved in controlling common scab development

Rates and intensity of freeze-thaw cycles affect nitrous oxide and carbon dioxide emissions from agricultural soils

In cool temperate regions, large emissions of nitrous oxide (N2O), an important greenhouse and ozone-depleting gas, have been observed during freeze–thaw (FT) cycles. However, it is unclear how freezing and thawing rates, freezing intensity, and freezing duration influence N2O emissions. We used a laboratory incubation to measure N2O emissions from two soils (sandy loam, silty clay) undergoing a single FT cycle of various freezing and thawing rates [rapid (0.5 °C h−1) vs. slow (0.017 °C h−1)], freezing intensity (−1 vs. −3 °C), and freezing duration (24 vs. 48 freezing degree-days). In general, soil carbon dioxide fluxes during freezing were highest when soils were frozen slowly at −1 °C, whereas fluxes after thawing were highest from the soils frozen and thawed rapidly at −3 °C. Soil N2O emissions during both the freezing and thawing periods were greatest in the soils exposed to rapid freezing to −3 °C, intermediate under rapid freezing to −1 °C and slow freezing to −3 °C, and smallest under slow freezing to −1 °C and the control treatment (constant +1 °C). The similar N2O emissions between the unfrozen control and the slowly frozen −1 °C treatment was unexpected as previous field studies with similar freezing rates and temperatures still experienced high N2O emissions during thaw. This suggests that the physical disruptions caused by freezing and thawing of the surface soil are not the primary driver of FT-induced N2O emissions under field conditions.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Seasonal changes in the abundance and activity of bacterial and fungal denitrifying communities associated with different compost amendments

Composts can be efficient organic amendments in potato culture as they can supply carbon and nutrients to the soil. However, more information is required to the effects of composts on denitrification and nitrous oxide emissions (N2O) and the emission-producing denitrifying communities. The effect of three compost amendments (municipal source separated organic waste compost (SSOC), forestry waste mixed with poultry manure compost (FPMC), and forestry residues compost (FRC)) on fungal and bacterial denitrifying communities and activity was examined in an agricultural field cropped to potatoes in during the fall, spring and summer seasons. The denitrification enzyme activity (DEA), N2O emissions and respiration were measured in parallel. N2O emission rates were greater in FRC-amended soils in the fall and summer, while soil respiration was highest in SSOC-amended soil in the fall. A large number of nirK denitrifying fungal transcripts was detected in the fall, coinciding with compost application while the greatest nirK bacterial transcripts were measured in the summer when plants were actively growing. Denitrifying community and transcript levels were poor predictors of DEA, N2O emissions or respiration rates in compost-amended soil. Overall, the sampling date was driving the population and activity levels of the three denitrifying communities under study.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Nitric Oxide Reductase Gene Expression and Nitrous Oxide Production in Nitrate-Grown Pseudomonas mandelii▿

Pure cultures of Pseudomonas mandelii were incubated with or without nitrate, which acts as a substrate and an electron acceptor for denitrification. Nitric oxide reductase (cnorB) gene expression was measured using a quantitative reverse transcription-PCR, and nitrous oxide emissions were measured by gas chromatography. P. mandelii cells in either the presence or absence of nitrate demonstrated an increase in cnorB gene expression during the first 3 h of growth. The level of expression of cnorB in nitrate-amended cells remained high (average, 2.06 × 108 transcripts/μg of RNA), while in untreated cells it decreased to an average of 3.63 × 106 transcripts/μg of RNA from 4 to 6 h. Nitrous oxide accumulation in the headspace was detected at 2 h, and cumulative emissions continued to increase over a 24-h period to 101 μmol in nitrate-amended cells. P. mandelii cnorB gene expression was not detected under aerobic conditions. These results demonstrate that P. mandelii cnorB gene expression was induced 203-fold at 4 h when nitrate was present in the medium. Accumulations of N2O indicated that the cNorB enzyme was synthesized and active

Effect of pH and Temperature on Denitrification Gene Expression and Activity in Pseudomonas mandelii▿

Pseudomonas mandelii liquid cultures were studied to determine the effect of pH and temperature on denitrification gene expression, which was quantified by quantitative reverse transcription-PCR. Denitrification was measured by the accumulation of nitrous oxide (N2O) in the headspace in the presence of acetylene. Levels of gene expression of nirS and cnorB at pH 5 were 539-fold and 6,190-fold lower, respectively, than the levels of gene expression for cells grown at pH 6, 7, and 8 between 4 h and 8 h. Cumulative denitrification levels were 28 μmol, 63 μmol, and 22 μmol at pH 6, 7, and 8, respectively, at 8 h, whereas negligible denitrification was measured at pH 5. P. mandelii cells grown at 20°C and 30°C exhibited 9-fold and 94-fold increases in levels of cnorB expression between 0 h and 2 h, respectively, and an average 17-fold increase in levels of nirS gene expression. In contrast, induction of cnorB and nirS gene expression for P. mandelii cells grown at 10°C did not occur in the first 4 h. Levels of cumulative denitrification at 10 h were 6.6 μmol for P. mandelii cells grown at 10°C and 20°C and 30 μmol for cells grown at 30°C. Overall, levels of cnorB and nirS expression were relatively insensitive to pH values over the range of pH 6 to 8 but were substantially reduced at pH 5, whereas gene expression was sensitive to temperature, with induction and time to achieve maximum gene expression delayed as the temperature decreased from 30°C. Low pH and temperature negatively affected denitrification activity