Early Successional Microhabitats Allow the Persistence of Endangered Plants in Coastal Sand Dunes

Many species are adapted to disturbance and occur within dynamic, mosaic landscapes that contain early and late successional microhabitats. Human modification of disturbance regimes alters the availability of microhabitats and may affect the viability of species in these ecosystems. Because restoring historical disturbance regimes is typically expensive and requires action at large spatial scales, such restoration projects must be justified by linking the persistence of species with successional microhabitats. Coastal sand dune ecosystems worldwide are characterized by their endemic biodiversity and frequent disturbance. Dune-stabilizing invasive plants alter successional dynamics and may threaten species in these ecosystems. We examined the distribution and population dynamics of two federally endangered plant species, the annual Layia carnosa and the perennial Lupinus tidestromii, within a dune ecosystem in northern California, USA. We parameterized a matrix population model for L. tidestromii and examined the magnitude by which the successional stage of the habitat (early or late) influenced population dynamics. Both species had higher frequencies and L. tidestromii had higher frequency of seedlings in early successional habitats. Lupinus tidestromii plants in early successional microhabitats had higher projected rates of population growth than those associated with stabilized, late successional habitats, due primarily to higher rates of recruitment in early successional microhabitats. These results support the idea that restoration of disturbance is critical in historically dynamic landscapes. Our results suggest that large-scale restorations are necessary to allow persistence of the endemic plant species that characterize these ecosystems

Non-acute Cognitive Sequelae Associated With Recreational Ecstasy Use: A Meta-analysis

Studies using animal models have found considerable evidence of neurological damage resulting from exposure to 3,4- methylenedioxymethamphetamine (MDMA, ecstasy). Yet, studies comparing the cognitive performance of human recreational ecstasy users to ecstasy naïve controls have produced inconsistent results. The present study is a meta-analysis of the published empirical literature on the cognitive sequelae of human recreational ecstasy use. The pooled effect size estimate for combined cognitive domains was statistically significant and moderate in size. Small to large, statistically significant aggregate effect sizes resulted for eight of the nine cognitive ability domains included in the analysis. Moderator analyses suggested that frequent ecstasy use is associated with greater cognitive impairment, cognitive impairment can occur after relatively low amounts of total lifetime cumulative use, and recovery of functioning does not occur within one year post cessation

Evaluating a pass/fail grading model in first year undergraduate computing.

This Innovative Practice Full Paper investigates the implications of implementing a Pass/Fail marking scheme within the undergraduate curriculum, specifically across first year computing modules in a Scottish Higher Education Institution. The motivation for this implementation was to ease stress and pressure on students entering higher education, which became particularly relevant following the COVID-19 pandemic. The study reports on the results of a survey that gathered feedback from Stage 1 and Stage 2 students who experienced the Pass/Fail implementation, and results shows that students generally appreciate the Pass/Fail model, although for many, the benefits only become apparent once they are exposed to alternative grading models. A number of recommendations are made for the implementation of similar marking schemes within computing in Higher Education curricula

Qualitative assessment of a Context of Consumption Framework to inform regulation of cigarette pack design in the U.S.

INTRODUCTION Researchers and regulators need to know how changes to cigarette packages can influence population health. We sought to advance research on the role of cigarette packaging by assessing a theory-informed framework from the fields of design and consumer research. The selected Context of Consumption Framework posits cognitive, affective, and behavioral responses to visual design. To assess the Framework’s potential for guiding research on the visual design of cigarette packaging in the U.S., this study seeks to understand to what extent the Context of Consumption Framework converges with how adult smokers think and talk about cigarette pack designs. METHODS Data for this qualitative study came from six telephone-based focus groups conducted in March 2017. Two groups consisted of lesbian, gay, and bisexual participants; two groups of participants with less than four years college education; one group of LGB and straight identity; and one group the general population. All groups were selected for regional, gender, and racial/ethnic diversity. Participants (n=33) represented all nine U.S. Census divisions. We conducted a deductive qualitative analysis. RESULTS Cigarette package designs captured the participants’ attention, suggested the characteristics of the product, and reflected (or could be leveraged to convey) multiple dimensions of consumer identity. Particular to the affective responses to design, our participants shared that cigarette packaging conveyed how the pack could be used to particular ends, created an emotional response to the designs, complied with normative expectations of a cigarette, elicited interest when designs change, and prompted fascination when unique design characteristics are used. CONCLUSIONS Use of the Context of Consumption Framework for cigarette product packaging design can inform regulatory research on tobacco product packaging. Researchers and regulators should consider multiple cognitive, affective, and behavioral responses to cigarette pack design

Plant Tolerance: A Unique Approach to Control Hemipteran Pests

Plant tolerance to insect pests has been indicated to be a unique category of resistance, however, very little information is available on the mechanism of tolerance against insect pests. Tolerance is distinctive in terms of the plant’s ability to withstand or recover from herbivore injury through growth and compensatory physiological processes. Because plant tolerance involves plant compensatory characteristics, the plant is able to harbor large numbers of herbivores without interfering with the insect pest’s physiology or behavior. Some studies have observed that tolerant plants can compensate photosynthetically by avoiding feedback inhibition and impaired electron flow through photosystem II that occurs as a result of insect feeding. Similarly, the up-regulation of peroxidases and other oxidative enzymes during insect feeding, in conjunction with elevated levels of phytohormones can play an important role in providing plant tolerance to insect pests. Hemipteran insects comprise some of the most economically important plant pests (e.g., aphids, whiteflies), due to their ability to achieve high population growth and their potential to transmit plant viruses. In this review, results from studies on plant tolerance to hemipterans are summarized, and potential models to understand tolerance are presented

Local adaptation constrains drought tolerance in a tropical foundation tree

Plant species with broad climatic ranges might be more vulnerable to climate change than previously appreciated due to intraspecific variation in climatic stress tolerance. In tropical forests, drought is increasingly frequent and severe, causing widespread declines and altering community dynamics. Yet, little is known about whether foundation tropical trees vary in drought tolerance throughout their distributions, and how intraspecific variation in drought tolerance might contribute to their vulnerability to climate changE. We tested for local adaptation in seedling emergence and establishment with a full-factorial reciprocal transplant experiment including 27 populations and 109,350 seeds along a 3,500 mm precipitation gradient for a widespread tropical foundation tree, Metrosideros polymorpha, in Hawaii. To more precisely relate seedling performance to soil moisture, we conducted a complementary greenhouse experiment to test responses of the same focal populations to simulated drought. In the reciprocal transplant experiment, we observed significant variation among populations and sites in germination and seedling establishment rates. Overall, there was a significant link between historical rainfall of populations and their performance under current rainfall at the study sites consistent with local adaptation. In particular, populations from historically wet sites demonstrated lower germination rates in currently dry sites compared to wet field sites, while populations from historically dry sites germinated well across all sites, with particularly high germination in dry sites. In the greenhouse, seedlings from wet populations survived fewer days without water, and succumbed at wetter soil conditions than populations from historically dry sites, corroborating results from the field experiment. Synthesis. While climate change models project the greatest drying trends for historically dry areas in Hawaii, even moderate drying of wet sites could significantly reduce Metrosideros polymorpha recruitment given the sensitivity of seedlings to very slight changes in water regimes. Thus, although M. polymorpha demonstrates high seedling drought tolerance in some populations, providing evidence of resilience at the species-scale, there are nonetheless vulnerable populations that will likely decline under climate change. Our approach demonstrates that even trees with high dispersal abilities can show significant clines in drought tolerance, and suggests that similar intraspecific variation might be an important consideration for other tropical foundational tree species

Grow them and we will come for the feast

Sustainable production of switchgrass and other bioenergy grasses will require eff ective pest management. Identifi cation of potential insect pests and detailed characterization of the plant-insect interaction will better enable us to address emergent insect pests in production fi elds. An added uncertainty is how manipulation of plants for improved quality (e.g. lower lignin) will aff ect plant resistance to insect herbivory. Plants can utilize different mechanisms to defend against chewing versus piercing-sucking insects; however, some basal plant responses appear to be shared across diverse biotic stressors. Th e range and modulation of these responses are beginning to be addressed for several of the temperate, perennial, warm-season grasses that are designated as biomass crops. Other systems have demonstrated the need to become proactive in these studies. For instance, buff alograss, Buchloë dactyloides (Nuttall) Engelmann, was fi rst introduced as a low-maintenance turf species. However, a number of important insect pests were documented within a relatively short time frame.1,2 Similarly, several recent reports have been published for switchgrass (Panicum virgatum L.) and Miscanthus (Miscanthus x giganteus) that indicate the presence of insect pests in production fi elds, and the overall susceptibility of these species to insect herbivory.3-

Feeding behavior of \u3ci\u3eAphis glycines\u3c/i\u3e (Hemiptera: Aphididae) on soybeans exhibiting antibiosis, antixenosis, and tolerance resistance

Aphis glycines Matsumura (Hemiptera: Aphididae) is a serious pest of soybean in North America. Plant resistance is a valuable tool for the management of this pest, and a better understanding of the interactions between aphid and soybeans expressing varying levels and different categories of resistance can assist in the development of aphid resistant or tolerant genotypes. The electrical penetration graph (EPG) technique was used to evaluate the feeding behavior of A. glycines (biotype 1) on 4 soybean genotypes: (1) ‘Dowling’ (contains Rag1 gene and exhibits antibiosis); (2) PI 200538 (contains Rag2 gene and exhibits antixenosis); (3) KS4202 (exhibits tolerance); and (4) ‘SD76RR’ (susceptible to aphid). Aphids spent shorter periods in the sieve element phase on ‘Dowling’ and exhibited a greater number of pathway phases, non-probing events, and a longer time in nonprobing events in PI 200538 and ‘Dowling.’ For ‘SD76RR’ and KS4202, aphids demonstrated more sustained phloem ingestion, spent shorter time in non-probing events, and exhibited fewer pathway phases and potential drops. These results indicate that resistance factors are present in the phloem of ‘Dowling.’ For PI 200538, it is suggested that antixenotic factors are involved in resistance to A. glycines. Because KS4202 is tolerant to biotype 1 of A. glycines, the suitability of this genotype was expected already. This study provides important data that contribute to the understanding of how soybean aphids (biotype 1) feed on soybean genotypes with various aphid resistant genes and categories. In addition to assisting in the distinction between resistance categories, these results are useful in soybean breeding programs focusing on developing genotypes with greater resistance to insects. Aphis glycines Matsumura (Hemiptera: Aphididae) é uma das principais pragas da cultura da soja na América do Norte. Dentre as técnicas de manejo da praga, a resistência de plantas a insetos se destaca como uma ferramenta valiosa. Assim, uma melhor compreensão sobre as interações entre o afídeo e plantas de soja que expressam variáveis níveis e diferentes categorias de resistência, pode auxiliar no desenvolvimento de genótipos resistentes ao inseto. A técnica de EPG foi utilizada para avaliar o comportamento alimentar de A. glycines (biótipo 1) em 4 genótipos de soja: (1) ‘Dowling’ (contém gene Rag1 e expressa antibiose); (2) PI 200538 (contém gene Rag2 e expressa antixenose); (3) KS4202 (expressa tolerância); e (4) ‘SD76RR’ (suscetível ao afídeo). Os afídeos demonstraram curtos períodos de alimentação na fase de seiva em ‘Dowling’ e exibiram uma grande quantidade de fases de caminhamento estiletar, número de períodos de não-prova e longos período de não-prova em PI 200538 e ‘Dowling.’ Para ‘SD76RR’ e KS4202, os afídeos mostraram um maior período de alimentação em vasos do floema, apresentaram curtos períodos de não-prova e exibiram poucas fases de caminhamento estiletar, além de menor número de quedas de potencial. Os resultados indicam que fatores de resistência estão presentes nos vasos floemáticos de ‘Dowling.’ Para PI200538, sugere-se que fatores antixenóticos estão envolvidos na resistência a A. glycines. Uma vez que KS4202 expressa tolerância ao biótipo 1 de A. glycines, a adequabilidade deste genótipo como fonte de alimento para o inseto já era esperada. Este estudo fornece importantes dados que contribuem para um melhor entendimento de como o pulgão-da-soja (biótipo 1) se alimentam de plantas de soja portadoras de diferentes genes e categorias de resistência. Além de auxiliar na distinção entre as categorias de resistência, esses resultados podem ser úteis em programas de melhoramento de soja, com intuito de selecionar genótipos mais resistentes a insetos

Feeding behavior of \u3ci\u3eAphis glycines\u3c/i\u3e (Hemiptera: Aphididae) on soybeans exhibiting antibiosis, antixenosis, and tolerance resistance

Aphis glycines Matsumura (Hemiptera: Aphididae) is a serious pest of soybean in North America. Plant resistance is a valuable tool for the management of this pest, and a better understanding of the interactions between aphid and soybeans expressing varying levels and different categories of resistance can assist in the development of aphid resistant or tolerant genotypes. The electrical penetration graph (EPG) technique was used to evaluate the feeding behavior of A. glycines (biotype 1) on 4 soybean genotypes: (1) ‘Dowling’ (contains Rag1 gene and exhibits antibiosis); (2) PI 200538 (contains Rag2 gene and exhibits antixenosis); (3) KS4202 (exhibits tolerance); and (4) ‘SD76RR’ (susceptible to aphid). Aphids spent shorter periods in the sieve element phase on ‘Dowling’ and exhibited a greater number of pathway phases, non-probing events, and a longer time in nonprobing events in PI 200538 and ‘Dowling.’ For ‘SD76RR’ and KS4202, aphids demonstrated more sustained phloem ingestion, spent shorter time in non-probing events, and exhibited fewer pathway phases and potential drops. These results indicate that resistance factors are present in the phloem of ‘Dowling.’ For PI 200538, it is suggested that antixenotic factors are involved in resistance to A. glycines. Because KS4202 is tolerant to biotype 1 of A. glycines, the suitability of this genotype was expected already. This study provides important data that contribute to the understanding of how soybean aphids (biotype 1) feed on soybean genotypes with various aphid resistant genes and categories. In addition to assisting in the distinction between resistance categories, these results are useful in soybean breeding programs focusing on developing genotypes with greater resistance to insects. Aphis glycines Matsumura (Hemiptera: Aphididae) é uma das principais pragas da cultura da soja na América do Norte. Dentre as técnicas de manejo da praga, a resistência de plantas a insetos se destaca como uma ferramenta valiosa. Assim, uma melhor compreensão sobre as interações entre o afídeo e plantas de soja que expressam variáveis níveis e diferentes categorias de resistência, pode auxiliar no desenvolvimento de genótipos resistentes ao inseto. A técnica de EPG foi utilizada para avaliar o comportamento alimentar de A. glycines (biótipo 1) em 4 genótipos de soja: (1) ‘Dowling’ (contém gene Rag1 e expressa antibiose); (2) PI 200538 (contém gene Rag2 e expressa antixenose); (3) KS4202 (expressa tolerância); e (4) ‘SD76RR’ (suscetível ao afídeo). Os afídeos demonstraram curtos períodos de alimentação na fase de seiva em ‘Dowling’ e exibiram uma grande quantidade de fases de caminhamento estiletar, número de períodos de não-prova e longos período de não-prova em PI 200538 e ‘Dowling.’ Para ‘SD76RR’ e KS4202, os afídeos mostraram um maior período de alimentação em vasos do floema, apresentaram curtos períodos de não-prova e exibiram poucas fases de caminhamento estiletar, além de menor número de quedas de potencial. Os resultados indicam que fatores de resistência estão presentes nos vasos floemáticos de ‘Dowling.’ Para PI200538, sugere-se que fatores antixenóticos estão envolvidos na resistência a A. glycines. Uma vez que KS4202 expressa tolerância ao biótipo 1 de A. glycines, a adequabilidade deste genótipo como fonte de alimento para o inseto já era esperada. Este estudo fornece importantes dados que contribuem para um melhor entendimento de como o pulgão-da-soja (biótipo 1) se alimentam de plantas de soja portadoras de diferentes genes e categorias de resistência. Além de auxiliar na distinção entre as categorias de resistência, esses resultados podem ser úteis em programas de melhoramento de soja, com intuito de selecionar genótipos mais resistentes a insetos

Divergent Switchgrass Cultivars Modify Cereal Aphid Transcriptomes

Schizaphis graminum Rondani (Hemiptera: Aphididae) and Sipha flava Forbes (Hemiptera: Aphididae) are two common pests of bioenergy grasses. Despite the fact that they are both considered generalists, they differ in their ability to colonize Panicum virgatum cultivars. For example, S. flava colonizes both P. virgatum cv. Summer and P. virgatum cv. Kanlow whereas S. graminum can only colonize Summer. To study the molecular responses of these aphids to these two switchgrass cultivars, we generated de novo transcriptome assemblies and compared the expression profiles of aphids feeding on both cultivars to profiles associated with feeding on a highly susceptible sorghum host and a starvation treatment. Transcriptome assemblies yielded 8,428 and 8,866 high-quality unigenes for S. graminum and S. flava, respectively. Overall, S. graminum responded strongly to all three treatments after 12 h with an upregulation of unigenes coding for detoxification enzymes while major transcriptional changes were not observed in S. flava until 24 h. Additionally, while the two aphids responded to the switchgrass feeding treatment by downregulating unigenes linked to growth and development, their responses to Summer and Kanlow diverged significantly. Schizaphis graminum upregulated more unigenes coding for stress-responsive enzymes in the Summer treatment compared to S. flava; however, many of these unigenes were actually downregulated in the Kanlow treatment. In contrast, S. flava appeared capable of overcoming host defenses by upregulating a larger number of unigenes coding for detoxification enzymes in the Kanlow treatment. Overall, these findings are consistent with previous studies on the interactions of these two cereal aphids to divergent switchgrass hosts