Bidder Support in Multi-item Multi-unit Continuous Combinatorial Auctions: A Unifying Theoretical Framework

Combinatorial auctions have seen limited applications in large-scale consumer-oriented marketplaces, partly due to the substantial complexity to keep track of auction status and formulate informed bidding strategies. We study the bidder support problem for the general multi-item multi-unit (MIMU) combinatorial auctions, where multiple heterogeneous items are being auctioned and multiple homogeneous units are available for each item. Under two prevalent bidding languages (OR bidding and XOR bidding), we derive theoretical results and design efficient algorithmic procedures to calculate important bidder support information, such as the winning bids of an auction and the minimum bidding value for a bid to win an auction either immediately or potentially in the future. Our results unify the theoretical insights on bidder support problem for different bidding languages as well as different special cases of general MIMU auctions, namely the single-item multi-unit (SIMU) auctions and the multi-item single-unit (MISU) auctions. We also consider auctions with additional bidding constraints, including batch-based combinatorial auctions and hierarchical combinatorial auctions, as well as the combinatorial reverse auctions, all of which have relevant practical applications (e.g., industrial procurements). Our results can be readily extended to solve the bidder support problems in these auction mechanisms.

Mediation Effect of Self-Efficacy and Resilience on the Psychological Well-Being of Lebanese People During the Crises of the COVID-19 Pandemic and the Beirut Explosion

Introduction: Self-efficacy signifies an individual's belief in their own ability to perform the actions required to achieve a particular performance. In this study, we used an online survey to assess the mediation effect of resilience and self-efficacy on the overall psychological well-being of Lebanese people during the crises of the COVID-19 pandemic and the Beirut explosion.Methods: Overall, 567 Lebanese people participated in an online survey between March 17–28, 2021. The survey included the Stress and Anxiety to Viral Epidemics-6 items (SAVE-6), Patient Health Questionnaire-9 (PHQ-9), Connor–Davidson Resilience Scale-2 items, WHO-5 Well-being Index, General Self-Efficacy scale, and a single item on insomnia. We also assessed their risk perception regarding exposure to COVID-19 or explosions.Results: About 53% of participants were assessed as having depression (PHQ-9 ≥ 10) in the recent crisis. About half of participants (53.2%) reported feeling more stressed by COVID-19 than by the Beirut explosion, and 23.4% felt more stressed by the Beirut explosion than by COVID-19. Only the SAVE-6 score differed significantly between groups with greater stress responses to COVID-19 and the Beirut explosion. Self-efficacy mediated the influence of depression on people's psychological well-being, and self-efficacy and resilience mediated the influence of viral anxiety on psychological well-being.Conclusion: Self-efficacy is important for reducing people's depression and improving their psychological well-being during the Lebanon crises and also mediates the influence of anxiety in response to the viral epidemic on their psychological well-being in some people.

Evaluating How Mental Health Changed in Australia through the COVID-19 Pandemic: Findings from the ‘Taking the Pulse of the Nation’ (TTPN) Survey

The COVID-19 pandemic has had a significant impact on mental health at the level of the population. The current study adds to the evidence base by examining how the prevalence of psychological distress changed in Australia during the pandemic. The study also assesses the psychometric properties of a new single-item measure of mental distress included in a survey program conducted regularly throughout the pandemic. Data are from 1158 respondents in wave 13 (early July 2020) of the nationally representative Taking the Pulse of the Nation (TTPN) Survey. The questionnaire included the six-item Kessler Psychological Distress Scale (K6) and a new single-item measure of distress. Results show a significant increase in the prevalence of psychological distress in Australia, from 6.3% pre-pandemic to 17.7% in early July 2020 (unadjusted odds ratio = 3.19; 95% CI (confidence interval) = 2.51 to 4.05). The new single-item measure of distress is highly correlated with the K6. This study provides a snapshot at one point in time about how mental health worsened in Australia during the COVID-19 pandemic. However, by demonstrating the accuracy of the new single-item measure of distress, this analysis also provides a basis for further research examining the trajectories and correlates of distress in Australia across the pandemic.

Does fear mediate the neuroticism-psychopathology link for adults living through the COVID-19 pandemic?

Background COVID-19 has globally increased psychological distress. Although research has shown a clear link between neuroticism and psychopathology, pandemic fears—manifesting as fear of death and coronavirus anxiety, have not been examined as mediating factors for explaining this connection during the pandemic. Methods Therefore, to fill this void in the literature, this study examined 259 U.S. MTurk adult workers in May 2020 using an online questionnaire. The study used the Patient Health Questionnaire, the 8-item Big Five Inventory neuroticism subscale, a single-item fear of death measure, and the Coronavirus Anxiety Scale as well as collected demographic information to perform correlational and meditation analyses. Results The results showed that both coronavirus anxiety and fear of death partially mediated the relationship between neuroticism and symptoms of depression and generalized anxiety. The results also found that those high in trait neuroticism who were fearful of death or had coronavirus anxiety showed heightened levels of depression and general anxiety. Conclusion This study’s findings were consistent with previous research and current work on pandemic-related distress. In addition, the results of these findings can help bring to light the connectedness of these psychopathological constructs with fears surrounding the pandemic—which can be useful to both researchers and mental health professionals alike.

Sampling bias in Brazilian studies on transgender and gender diverse populations: the two-step measure for assessing gender identity in surveys

Correctly recognizing gender identity in population-based surveys is essential to develop effective public health strategies to improve the living conditions of transgender and gender-diverse populations, as well as to adequately collect data on cisgender individuals. This study aims to present the two-step measure as the best strategy for assessing gender identity in Brazilian surveys, thus we performed two separate analyses. Firstly, we conducted a systematic review concerning HIV-related care among Brazilian transgender and gender-diverse populations to assess the strategy used to identify participants’ gender identity. Secondly, we re-analyzed data from a recent survey that included Brazilian transgender populations, comparing characteristics and health outcomes from the sample identified by single-item and by the two-step measure. Concerning the systematic review, from 6,585 references, Brazilian research teams published seven articles, and only one study used the two-step measure. Regarding this survey, the two-step measure recognized 567 cisgender and 773 transgender and gender diverse participants among the 1,340 participants who answered the questionnaire, whereas the single-item measure was able to recognize only 540 transgender and gender diverse people. Furthermore, 31 transgender women self-identified as “transgender men” on the single-item measure. Therefore, although scarcely used in Brazil, the two-step measure is a more accurate strategy to recognize gender identity.

Bodies in Cinema: Evaluating Operationalisations of Closeness to Movie Characters

Based on theoretical considerations on embodied affectivity in social life, the feeling of being close is argued to be pivotal for experiencing one-sided interactions with movie characters. Currently, a feasible methodology to be used in order to measure this variable is still missing. A subsample (n = 14) from existing data is used to evaluate three operationalisations of closeness to the main character in two central scenes of the movie Sehnsucht by Valeska Grisebach: (1) Closeness as grades of familiarity is operationalised using a pictorial measure with the participant indicating which of two more or less overlapping circles (one representing the self, one representing the screen character) describes the relationship best. (2) Physical closeness is assessed with recordings of the eye movements which provide a fine-grained measurement of distance to the screen. (3) Closeness as synchronicity could be observed by analysing the facial expressions and movements of the participant in front of the screen simultaneously with the expressions and movements of the movie characters. The results of the study point to limitations of an operationalisation of closeness as familiarity by using a single-item measurement. Furthermore, with synchronicity being rarely observed, this way of being close appears to be a phenomenon of minor relevance for movie reception. The measurement of physical closeness, however, indicates a promising approach due to behavioural patterns being detectable and easily interpretable in accordance with the movie’s content. Ideas for further methodological development of an operationalisation of physical closeness are proposed.

Traditional usage of underutilized aquatic plants found in the Imphal valley of Manipur

The paper focuses on the traditional usage of aquatic plants found in the wetland areas of the Imphal valley of Manipur. From the survey, 30 aquatic plants have been collected use for the management of various health conditions. Most of the collected plants consume as daily food items, some used for specic remedial purposes in the treatment of certain types of ailments and diseases like cough, fever, ulcer, piles, diarrhea, jaundice, skin diseases, rheumatic pain, diabetes, hypertension, urinary troubles, body pain, respiratory problems, urinary problems, cardiovascular diseases, etc. Accordingly, different parts of the plant are used as a single item or by mixing with other ingredients in various forms of fresh or raw, culinary, or as a tonic or dry or powder form to treat the diseases. The aquatic plants also incorporate in the preparation of various traditional dishes. 70% of collected wetland plants are marketable provides a means of livelihood and source of income for the poor and needy people. Therefore, proper documentation and preservation of traditional knowledge are essential that may provide useful for future generations through research in pharmaceuticals and drug discovery.

Are hedonia and eudaimonia higher on vacation than at home? Initial empirical evidence and a toolbox for future research

Vacations are assumed to be characterised by enjoyment. More specifically, the level of enjoyment on vacation is assumed to be substantially higher than that of a normal day at home. Yet, this assumption has never been empirically tested. This study provides initial empirical evidence for the fact that all enjoyment-related constructs at the core of positive psychology (hedonic trait and state motivation/orientation and experience, and eudaimonic trait and state motivation/orientation and experience) are significantly higher on vacation than in the normal, everyday home context. To arrive at these empirical findings, the study also introduces to tourism research a conceptual framework that unambiguously defines the most commonly used eudaimonic and hedonic constructs and develops and empirically assesses appropriate single-item measures.

Dexamethasone and hiccups: a 2000-patient, telephone-based study

ObjectivesDexamethasone causes hiccups in an undefined percentage of patients, and these hiccups are often ignored (‘My doctors just shook their heads like I was joking …’). This study sought to learn the percentage of dexamethasone-treated patients who develop hiccups and to explore patients’ responses to the availability of educational materials on hiccups.MethodsEnglish-speaking, adult outpatients treated with oral, intravenous or epidural dexamethasone 2 weeks prior were contacted by phone and asked about hiccups. Educational materials were offered, and patients were queried on their opinion of the availability of such materials.ResultsOne hundred and twenty-seven patients or 11% (95% CI 9% to 13%) reported hiccups. This percentage was derived from 1186 reachable patients from 2000 total patients. Fifty-four (43%) of those with hiccups desired to learn about educational materials. Of these, 49 completed a single-item, 5-point scale item: 21 (43%) viewed the availability of educational materials ‘extremely helpful,’ providing a 5 rating; 8 (16%) provided a 4; 4 (8%) provided a 3; and 1 (4%) provided a 2.ConclusionsDexamethasone-induced hiccups occur in a small percentage of patients. The fact that most patients responded favourably to learning about the availability of educational materials suggests some have unmet needs.