Metagenomic analysis of the gut microbiome of the common black slug Arion ater in search of novel lignocellulose degrading enzymes

Some eukaryotes are able to gain access to well-protected carbon sources in plant biomass by exploiting microorganisms in the environment or harbored in their digestive system. One is the land pulmonate Arion ater, which takes advantage of a gut microbial consortium that can break down the widely available, but difficult to digest, carbohydrate polymers in lignocellulose, enabling them to digest a broad range of fresh and partially degraded plant material efficiently. This ability is considered one of the major factors that have enabled A. ater to become one of the most widespread plant pest species in Western Europe and North America. Using metagenomic techniques we have characterized the bacterial diversity and functional capability of the gut microbiome of this notorious agricultural pest. Analysis of gut metagenomic community sequences identified abundant populations of known lignocellulose-degrading bacteria, along with well-characterized bacterial plant pathogens. This also revealed a repertoire of more than 3,383 carbohydrate active enzymes (CAZymes) including multiple enzymes associated with lignin degradation, demonstrating a microbial consortium capable of degradation of all components of lignocellulose. This would allow A. ater to make extensive use of plant biomass as a source of nutrients through exploitation of the enzymatic capabilities of the gut microbial consortia. From this metagenome assembly we also demonstrate the successful amplification of multiple predicted gene sequences from metagenomic DNA subjected to whole genome amplification and expression of functional proteins, facilitating the low cost acquisition and biochemical testing of the many thousands of novel genes identified in metagenomics studies. These findings demonstrate the importance of studying Gastropod microbial communities. Firstly, with respect to understanding links between feeding and evolutionary success and, secondly, as sources of novel enzymes with biotechnological potential, such as, CAZYmes that could be used in the production of biofuel

Queerblind Rhetoric in Anti-LGBTQ Politics

Anti-LGBTQ movements have gone through different phases in the United States as they have targeted homosexuality generally, same-sex marriage, and same-sex adoption. Despite the increasing acceptance and visibility of LGBTQ identities over the past twenty years, this anti-LGBTQ movement continues today, targeting what kids learn about in schools and LGBTQ youth generally. In this thesis, I research how opponents of LGBTQ rights frame their arguments in order to appeal to a more tolerant American public. Specifically, I analyze the rhetoric of anti-LGBTQ curriculum policies and anti-LGBTQ activism from 2022 and from an earlier period spanning from the 1970s to the early 2000s. I find that both policies and activism have changed their rhetoric to become more queerblind &ndash; intentionally avoiding terms or assigning value to LGBTQ identities. This queerblind theory is further developed by looking at how scholars have analyzed racially colorblind rhetoric that is more prevalent in modern-day racism and rhetoric. I argue that queerblind rhetoric has become more prevalent due to a more tolerant public and due to queerblindness being a more politically strategic opposition to the LGBTQ rights movement. </p

The interaction between temperament and the family environment in adolescent substance use and externalizing behaviors : support for diathesis–stress or differential susceptibility?

Both individual and environmental factors predict externalizing behaviors and substance use (EB-SU); however, different patterns of interaction among these factors may have different implications. This review first examines how temperament and the family environment interact in the prediction of adolescent EB-SU. Second, studies are reviewed according to two theoretical models: (1) diathesis–stress, i.e., certain individual characteristics are linked to vulnerability and later problems in adverse environments; (2) differential susceptibility, i.e., these characteristics are linked to susceptibility, predicting problems in adverse environments, but also better than average outcomes in good environments. Fourteen studies focusing on the prediction of EB-SU at ages 12–18 were selected through a literature search. Results showed that certain temperament traits (high levels of impulsivity and disinhibition; low levels of effortful control, negative affect, fearfulness and shyness), hereby designated as “adventurous” disposition, were associated with higher levels of EB-SU in adverse family environments. Some studies also showed that children with “adventurous” temperament traits in positive environments had the lowest levels of EB-SU. This suggests that prevention of EB-SU might target family factors such as parenting and focus on children with “adventurous” temperament traits. Further, studies that supported the differential susceptibility model were those assessing temperament and the family environment in childhood and studies that supported the diathesis–stress model assessed these variables in adolescence. It is thus possible that some of these “adventurous” temperament traits, with regard to EB-SU, would be indicators of susceptibility to both enriched and adverse environments in childhood but no longer in adolescence, when they would only be indicators of vulnerability to adverse environments

Adolescent cannabis use, change in neurocognitive function, and High-School Graduation : a longitudinal study from early adolescence to young adulthood

The main objective of this prospective longitudinal study was to investigate bidirectional associations between adolescent cannabis use (CU) and neurocognitive performance in a community sample of 294 young men from ages 13 to 20 years. The results showed that in early adolescence, and prior to initiation to CU, poor short-term and working memory, but high verbal IQ, were associated with earlier age of onset of CU. In turn, age of CU onset and CU frequency across adolescence were associated with (a) specific neurocognitive decline in verbal IQ and executive function tasks tapping trial and error learning and reward processing by early adulthood and (b) lower rates of high-school graduation. The association between CU onset and change in neurocognitive function, however, was found to be accounted for by CU frequency. Whereas the link between CU frequency across adolescence and change in verbal IQ was explained (mediated) by high school graduation, the link between CU frequency and tasks tapping trial and error learning were independent from high school graduation, concurrent cannabis and other substance use, adolescent alcohol use, and externalizing behaviors. Findings support prevention efforts aimed at delaying onset and reducing frequency of CU

The effect of contextual risk factors on the effectiveness of brief personality‐targeted interventions for adolescent alcohol use and misuse : a cluster‐randomized trial

Background A range of school‐based prevention programs has been developed and used to prevent, delay, or reduce alcohol use among adolescents. Most of these programs have been evaluated at the community‐level impact. However, the effect of contextual risk factors has rarely been considered in the evaluation of these programs. The aim of this study was to investigate the potential moderating effects of 2 important contextual risk factors (i.e., socioeconomic status [SES] and peer victimization) on the effectiveness of the school‐based personality‐targeted interventions (Preventure program) in reducing adolescent alcohol use over a 2‐year period using a cluster‐randomized trial. Methods High‐risk adolescents were identified using personality scores on the Substance Use Risk Profile Scale and randomized to intervention and control groups. Two 90‐minute cognitive behavioral therapy‐based group sessions targeted 1 of 4 personality risk profiles: Anxiety Sensitivity, Hopelessness, Impulsivity, or Sensation Seeking. Multilevel linear modeling of alcohol use, binge drinking, and drinking‐related harm was conducted to assess the moderating effect of baseline peer victimization and SES. Results Results indicated that the Preventure program was equally beneficial to all adolescents, regardless of SES and victimization history, in terms of their alcohol outcomes and related harm. Receiving the intervention was additionally beneficial for adolescents reporting peer victimization regarding their alcohol‐related harm compared to nonvictimized youth (β = −0.29, SE = 0.11, p = 0.014). Conclusions Findings suggest that the content of personality‐targeted interventions is beneficial for all high‐risk youth regardless of their SES or experience of peer victimization. The current study suggests that using targeted approaches, such as targeting underlying personality risk factors, may be the most appropriate substance use prevention strategy for high‐risk youth, as it is beneficial for all high‐risk youth regardless of their contextual risk factors

Mechanisms of personality-targeted intervention effects on adolescent alcohol misuse, internalising and externalising symptoms

Objective: This study aims to explore the mechanisms of personality-targeted intervention effects on problematic drinking, internalising and externalising symptoms. Method: As part of a cluster-randomised trial, 1210 high-risk students (mean age 13.7 years) in 19 London high schools (42.6% white, 54% male) were identified using the Substance Use Risk Profile Scale. Intervention school participants were invited to participate in personality-matched interventions by trained school staff. MacKinnon’s products of coefficients method was used to compare three complementary mechanism hypotheses, namely, whether early changes in i) alcohol use, ii) internalising and externalising symptoms or iii) personality during the 6 months post-intervention accounted for intervention effects over 2 years. Results: Early intervention effects on drinking behaviours during the 6 months postintervention partially accounted for longer term intervention effects on the onset of binge drinking (95% CI -.349 to -.062) and drinking problems (95% CI -.206 to -.016) over 2 years. Intervention effects on anxiety symptoms and conduct problems were partially mediated by early reductions in depressive symptoms (95% CI -.013 to -.001; 95% CI - .047 to -.001), and intervention effects on internalising symptoms were also partially mediated by reductions in anxiety sensitivity (95% CI -.003 to 0). Conclusions: 2 year intervention effects on problematic drinking were largely accounted for by early changes in drinking behaviours, and were not mediated by changes in mental health symptoms or personality risk factors. Early improvements in mood and anxiety sensitivity partially mediated longer term reductions in mental health problems

No-Three-in-a-Θ:\Theta: Variations on the No-Three-in-a-Line Problem

We pose a natural generalization to the well-studied and difficult no-three-in-a-line problem: How many points can be chosen on an $n \times n$ grid such that no three of them form an angle of $\theta$? In this paper, we classify which angles yield nontrivial problems, noting that some angles appear in surprising configurations on the grid. We prove a lower bound of $2n$ points for angles $\theta$ such that $135^\circ \leq \theta < 180^\circ$, and further explore the case $\theta = 135^\circ$, utilizing geometric properties of the grid to prove an upper bound of $3n - 2$ points. Lastly, we generalize the proof strategy used in proving the upper bound for $\theta = 135^\circ$ to provide a general upper bound for all angles.Comment: 15 pages, 16 figure

The Role of Dislodgement in the Territorial Ecology of the Owl Limpet, \u3cem\u3eLottia gigantea\u3c/em\u3e

Ascertaining the risks and benefits of different behaviors is a central goal of research on territoriality. Although most territorial behavior is ritualized, with concomitant reduced risks for both residents and intruders, this ritualization is generally found to be underpinned by rare, highly consequential, interactions. The agonistic behavior of the intertidal owl limpet, Lottia gigantea, involves defense of a feeding territory, and includes a relatively explosive thrusting response by territory holders against intruding conspecifics. We here ask whether this thrusting behavior is capable of entirely dislodging intruders from their rocky wave-swept substratum, thereby ridding the resident of future challenges by that intruder. Our field measurements of the strength of territorial thrusts, as well as thrust resistance, indicate that territorial limpets are strong enough to overcome the resistance of small to medium sized (\u3c40 mm) conspecifics encountered on their territories. Interestingly, at least 44% of the limpets dislodged from the rock substratum during a retreat or territorial response survived in a new location. Growth of these survivors was at least as rapid as that of undisturbed limpets in the old location. We conclude that shell thrusting during the territorial response of Lottia gigantea can reduce the cost of territorial defense by dislodging smaller conspecifics, thereby eliminating them from all future interactions. Conversely, the risk incurred by these smaller conspecifics while intruding onto territories of larger individuals is likely mitigated by the surprisingly high survival rate, and subsequent normal growth, of dislodged limpets