Simulations of a lattice model of two-headed linear amphiphiles: influence of amphiphile asymmetry

Using a 2D lattice model, we conduct Monte Carlo simulations of micellar aggregation of linear-chain amphiphiles having two solvophilic head groups. In the context of this simple model, we quantify how the amphiphile architecture influences the critical micelle concentration (CMC), with a particular focus on the role of the asymmetry of the amphiphile structure. Accordingly, we study all possible arrangements of the head groups along amphiphile chains of fixed length $N=12$ and 16 molecular units. This set of idealized amphiphile architectures approximates many cases of symmetric and asymmetric gemini surfactants, double-headed surfactants and boloform surfactants. Consistent with earlier results, we find that the number of spacer units $s$ separating the heads has a significant influence on the CMC, with the CMC increasing with $s$ for $s<N/2$. In comparison, the influence of the asymmetry of the chain architecture on the CMC is much weaker, as is also found experimentally.Comment: 30 pages, 17 fgure

Simulations of a lattice model of two-headed linear amphiphiles: influence of amphiphile asymmetry

Using a 2D lattice model, we conduct Monte Carlo simulations of micellar aggregation of linear-chain amphiphiles having two solvophilic head groups. In the context of this simple model, we quantify how the amphiphile architecture influences the critical micelle concentration (CMC), with a particular focus on the role of the asymmetry of the amphiphile structure. Accordingly, we study all possible arrangements of the head groups along amphiphile chains of fixed length $N=12$ and 16 molecular units. This set of idealized amphiphile architectures approximates many cases of symmetric and asymmetric gemini surfactants, double-headed surfactants and boloform surfactants. Consistent with earlier results, we find that the number of spacer units $s$ separating the heads has a significant influence on the CMC, with the CMC increasing with $s$ for $s<N/2$. In comparison, the influence of the asymmetry of the chain architecture on the CMC is much weaker, as is also found experimentally.Comment: 30 pages, 17 fgure

Generative AI in Computing Education: Perspectives of Students and Instructors

Generative models are now capable of producing natural language text that is, in some cases, comparable in quality to the text produced by people. In the computing education context, these models are being used to generate code, code explanations, and programming exercises. The rapid adoption of these models has prompted multiple position papers and workshops which discuss the implications of these models for computing education, both positive and negative. This paper presents results from a series of semi-structured interviews with 12 students and 6 instructors about their awareness, experiences, and preferences regarding the use of tools powered by generative AI in computing classrooms. The results suggest that Generative AI (GAI) tools will play an increasingly significant role in computing education. However, students and instructors also raised numerous concerns about how these models should be integrated to best support the needs and learning goals of students. We also identified interesting tensions and alignments that emerged between how instructors and students prefer to engage with these models. We discuss these results and provide recommendations related to curriculum development, assessment methods, and pedagogical practice. As GAI tools become increasingly prevalent, it's important to understand educational stakeholders' preferences and values to ensure that these tools can be used for good and that potential harms can be mitigated.Comment: 10 pages, 1 figur

Measurement properties of the EQ-5D across four major geriatric conditions: Findings from TOPICS-MDS

Background: As populations age, chronic geriatric conditions linked to progressive organ failure jeopardize health-related quality of life (HRQoL). Thus, this research assessed the validity and applicability of the EQ-5D (a common HRQoL instrument) across four major chronic geriatric conditions: hearing issues, joint damage, urinary incontinence, or dizziness with falls. Methods: The study sample comprised 25,637 community-dwelling persons aged 65 years and older residing in the Netherlands (Data source: TOPICS-MDS, www.topics-mds.eu ). Floor and ceiling effects were examined. To assess convergent validity, random effects meta-correlations (Spearman's rho) were derived between individual EQ-5D domains and related survey items. To further examine construct validity, the association between sociodemographic characteristics and EQ-5D summary scores were assessed using linear mixed models. Outcomes were compared to the overall study population as well as a 'healthy' subgroup reporting no major chronic conditions. Results: Whereas ceiling effects were observed in the overall study population and the 'healthy' subgroup, such was not the case in the geriatric condition subgroups. The majority of hypotheses regarding correlations between survey items and sociodemographic associations were supported. EQ-5D summary scores were lower in respondents who were older, female, widowed/single, lower educated, and living alone. Increasing co-morbidity had a clear negative effect on EQ-5D scores. Conclusion: This study supported the construct validity of the EQ-5D across four major geriatric conditions. For older persons who are generally healthy, i.e. reporting few to no chronic conditions, the EQ-5D confers poor discriminative ability due to ceiling effects. Although the overall dataset initially suggested poor discriminative ability for the EQ-5D, such was not the case within subgroups presenting with major geriatric conditions

Predicting the ecological impacts of a new freshwater invader: functional responses and prey selectivity of the ‘killer shrimp', dikerogammarus villosus, compared to the native Gammarus pulex

The ability to predict the likely ecological impacts of invasive species in fresh waters is a pressing research requirement. Whilst comparisons of species traits and considerations of invasion history have some efficacy in this respect, we require robust methods that can compare the effects of native and invasive species. Here, we utilise comparative functional responses and prey selectivity experiments to understand and predict the ecological impact of an invader as compared to a native. We compared the predatory functional responses of an emerging invasive species in Europe, the ‘killer shrimp’, Dikerogammarus villosus, and an analogous native species, Gammarus pulex, towards three representative prey species: Asellus aquaticus, Daphnia magna and Chironomus sp. Furthermore, as ecological impact may be greater for invasive species with more indiscriminate feeding habits, we compared the selectivity for the three prey types between the invasive and native species. In both the presence and absence of experimental habitats, large D. villosus, and those matched for body size with G. pulex, generally showed higher (Type II) functional responses than G. pulex, with the invasive species exhibiting higher maximum feeding rates. Further, D. villosus exhibited significantly more indiscriminate prey selection compared with G. pulex, a trait that became more evident as the invader increased in size. Differences in functional responses and prey selectivity were prey species specific, with higher to lower predicted impacts in the order A. aquaticus, D. magna and Chironomus sp. This is in accord with the impact of this invasive species on macroinvertebrates in the field. We thus provide understanding of the known ecological impact of D. villosus and discuss the utility of the phenomenological use of comparative functional responses and resource use as a tool through which the potential ecological impacts of invasive species may be identified.</p

Predators vs. alien: differential biotic resistance to an invasive species by two resident predators

The success of invading species can be restricted by interspecific interactions such as competition and predation (i.e. biotic resistance) from resident species, which may be natives or previous invaders. Whilst there are myriad examples of resident species preying on invaders, simply showing that such an interaction exists does not demonstrate that predation limits invader establishment, abundance or spread. Support for this conclusion requires evidence of negative associations between invaders and resident predators in the field and, further, that the predator-prey interaction is likely to strongly regulate or potentially de-stabilise the introduced prey population. Moreover, it must be considered that different resident predator species may have different abilities to restrict invaders. In this study, we show from analysis of field data that two European predatory freshwater amphipods, Gammarus pulex and Gammarus duebeni celticus, have strong negative field associations with their prey, the invasive North American amphipod Crangonyx pseudogracilis. This negative field association is significantly stronger with Gammarus pulex, a previous and now resident invader in the study sites, than with the native Gammarus duebeni celticus. These field patterns were consistent with our experimental findings that both resident predators display potentially population de-stabilising Type II functional responses towards the invasive prey, with a significantly greater magnitude of response exhibited by Gammarus pulex than by Gammarus duebeni celticus. Further, these Type II functional responses were consistent across homo- and heterogeneous environments, contrary to the expectation that heterogeneity facilitates more stabilising Type III functional responses through the provision of prey refugia. Our experimental approach confirms correlative field surveys and thus supports the hypothesis that resident predatory invertebrates are differentially limiting the distribution and abundance of an introduced invertebrate. We discuss how the comparative functional response approach not only enhances understanding of the success or failure of invasions in the face of various resident predators, but potentially also allows prediction of population- and community-level outcomes of species introductions

Bis[2,2′-(2-amino­ethyl­imino)­di(ethyl­ammonium)] di-μ-sulfido-bis[disulfido­stannate(IV)]

The asymmetric unit of the title compound, (C6H20N4)2[Sn2S6], comprises half of a [Sn2S6]4− anion and a diprotonated tris­(2-amino­eth­yl)amine cation. The anion lies on an inversion center, while the atoms of the cation occupy general positions. An intra­molecular N—H⋯N hydrogen bond is observed in the cation. In the crystal, strong N—H⋯S hydrogen bonding between the terminal sulfur atoms of the anion and the protonated amine N atoms of the cations result in a three-dimensional network

Mapping the Gaps: A Scoping Review of Virtual Care Solutions for Caregivers of Children with Chronic Illnesses

Background/Objectives: Caregivers of children with chronic illnesses, including chronic pain, experience high levels of distress, which impacts their own mental and physical health as well as child outcomes. Virtual care solutions offer opportunities to provide accessible support, yet most overlook caregivers&rsquo; needs. We conducted a scoping review to create an interactive Evidence and Gap Map (EGM) of virtual care solutions across a stepped care continuum (i.e., from self-directed to specialized care) for caregivers of youth with chronic illnesses. Methods: The review methodology was co-designed with four caregivers. Data sources were the peer-reviewed scientific literature and a call for innovations. Records were independently coded and assessed for quality. Results: Overall, 73 studies were included. Most virtual care solutions targeted caregivers of children with cancer, neurological disorders, and complex chronic illnesses. Over half were noted at lower levels of stepped care (i.e., self-guided apps and websites), with psychological strategies being predominant (84%). However, very few addressed caregivers&rsquo; physical health (15%) or provided family counseling (19%) or practical support (1%). Significant gaps were noted in interventions for managing caregiver chronic pain, despite its high prevalence and impact on child outcomes. Conclusions: Evidence and Gap Maps are innovative visual tools for knowledge synthesis, facilitating rapid, evidence-informed decision-making for patients, families, health professionals, and policymakers. This EGM highlighted high-quality virtual care solutions ready for immediate scaling and identified critical evidence gaps requiring prioritization. To address the complexities of pediatric chronic illnesses, including chronic pain, virtual care initiatives must prioritize family-centered, accessible, and equitable approaches. Engaging caregivers as partners is critical to ensure interventions align with their needs and priorities

Gender Role Attitudes and Prosecutorial Decision-Making in a Case of Intimate Partner Violence

Intimate Partner Violence (IPV) is a pervasive public health crisis that impacts individuals across the gender spectrum. Traditionally, IPV is conceptualized through a gendered lens, with men as the perpetrators and women as the victims. The current study explored the association between perpetrator/victim sex, prosecutor gender role attitudes, and prosecutorial decision-making in a case of alleged IPV. We hypothesized that prosecutors with more traditional gender role attitudes would be more lenient, and this effect to be exacerbated in cases involving a female perpetrator. Criminal prosecutors across the United States (N = 94) completed the Male Role Norms Inventory—Revised and read case materials describing the alleged IPV between a heterosexual couple (e.g., arrest report, medical records). The victim/perpetrator sex was manipulated to involve either a female- (male victim) or male- (female victim) perpetrated IPV case. Results indicate that gender role attitudes were not associated with prosecutorial decision-making. However, prosecutors perceived the violence as more serious and the perpetrator as more likely to reoffend when the perpetrator was male; further, they attributed more blame to the female victim. An interaction between perpetrator sex and prosecutor gender role attitudes indicates those with more traditional beliefs were more likely to blame the female (rather than male) victim. These data suggest extralegal factors related to the perpetrator (i.e., perpetrator sex), rather than prosecutor individual differences (i.e., gender role attitudes), are associated with prosecutor discretionary decision-making. In tandem with real-world disparities in the prosecution of IPV based on perpetrator sex, the current research stresses the importance of exploring a diversity of factors that account for these observed differences.This accepted article is published as MacNeil, E. R., Cox, J., Daquin, J. C., & Neal, T. M. S. (2024). Gender Role Attitudes and Prosecutorial Decision-Making in a Case of Intimate Partner Violence. Journal of Interpersonal Violence, 39(7-8), 1496-1518. https://doi.org/10.1177/08862605231207901. Posted with permission