bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and testing of a prototype foot orthosis that uses the principle of granular jamming
Authors: Simonds Emily , Colton Jonathan , Kogler Geza , Chang Young-Hui
Published: May 2021

Study Design:

A mechanical testing protocol was used to compare the material properties of commercially available foams with that of a newly designed granular jamming orthosis prototypes.

Background:

Foot orthoses have an inherent limitation of predetermined mechanical material properties coupled with a fixed orthotic interface shape that cannot be readily changed.

Objectives:

To develop and test a novel orthotic insole design concept that incorporates principles of granular jamming.

Methods:

Granular media were used in combination with vacuum pressure to create a variable stiffness granular foot orthosis. Four types of granular media (rice, poppy seeds, micropolystyrene, and polystyrene beads) were tested in different prototype configurations varying in volume fill and particulate size. Stress–strain curves were obtained from uniaxial compression tests to characterize granular foot orthosis prototypes in comparison with commercial orthotic foams.

Results:

Increasing vacuum pressure increased prototype stiffness for most configurations. A single granular jamming orthosis could exhibit energy absorption values that spanned the entire commercial foam performance range, and in some cases extended far beyond the upper values of the tested foams.

Conclusion:

The results suggest that granular jamming principles can provide clinicians the capability for rapid selection of mechanical properties over a wide range of orthosis stiffnesses. Importantly, patients could don the orthosis because the clinician makes real-time assessments and adjustments in the clinic.
Serum IgG1 and IgG4 could contribute to partial control of viral rebound in chronically HIV-1-infected patients
Authors: Pastori Claudia , Galli Laura , Siracusano Gabriel , Spagnuolo Vincenzo , Muccini Camilla , Mastrangelo Andrea , Bruzzesi Elena , Ranzenigo Martina , Chiurlo Matteo , Castagna Antonella , Lopalco Lucia
Published: May 2021

Objectives:

Few studies have investigated chronically infected individuals after antiretroviral therapy (ART) interruption (ATI, analytical therapy interruption); thus, we investigated the association between some HIV-specific antibodies and viral control.

Design:

All enrolled patients were previously described in the APACHE study. Briefly, the study was conducted on HIV-1 chronically infected patients, with HIV-RNA less than 50 copies/ml for at least 10 years, CD4+ cell count greater than 500 cells/μl and HIV-DNA less than 100 copies/106 PBMC. The ART regimen in use at the time of ATI was resumed at confirmed viral rebound (CVR, defined as two consecutive HIV-RNA >50 copies/ml).

Methods:

Collection of sera and analysis of both binding antibodies (BAbs) and neutralizing antibodies (NAbs) was performed at three different time points: ATI, CVR and time of viral re-suppression after ART resumption.

Results:

IgG subclasses (IgG1, IgG2, IgG3 and IgG4) from the four patients with highest levels of neutralization were found to block viral infection. All patients had CVR after ATI at a median time of 21 days (14–56). After ART resumption, all the enrolled patients achieved HIV-RNA less than 50 copies/ml in 42 days (21–98). We observed a strong increase of either BAbs and NAbs titers from ATI to viral re-suppression in one patient, who showed the longest period of virus undetectability during ATI. In this patient, BAbs and NAbs specifically belonged to both IgG1 and IgG4 subclasses, directed to env antigen.

Conclusion:

env-specific NAbs and BAbs belonging to IgG1, IgG4 subclasses could be helpful to monitor long-term responses able to control virus replication and eradicate HIV infection.
Safety and antibody response to the first dose of severe acute respiratory syndrome coronavirus 2 messenger RNA vaccine in persons with HIV
Authors: Ruddy Jake A. , Boyarsky Brian J. , Werbel William A. , Bailey Justin R. , Karaba Andrew H. , Garonzik-Wang Jacqueline M. , Segev Dorry L. , Durand Christine M.
Published: May 2021

In this study of 12 people with HIV (PWH) who received the first dose of SARS-CoV-2 mRNA vaccination, anti-SARS-CoV-2 receptor-binding domain antibodies were detectable in all participants; lower antibody levels were seen in those with lower CD4+ counts, and vaccine reactions were generally mild.
Spleen Stiffness Measurement by Using Shear-Wave Elastography as a Predictor of Progression to Secondary Myelofibrosis
Authors: Ekinci Omer , Ozgokce Mesut , Turko Ensar , Merter Mustafa
Published: May 2021

Objective

Polycythemia vera (PV) and essential thrombocythemia (ET) are chronic myeloproliferative diseases that can transform to secondary myelofibrosis (SMF). In this study, we evaluated spleen stiffness using shear-wave elastography (SWE) as a predictor of progression to SMF.

Methods

Participants were grouped as healthy volunteers (HVs), PV/ET patients, and SMF patients. Participants' spleen sizes, spleen stiffness values, bone marrow fibrosis degrees, and the other parameters were evaluated. Spleen stiffness values and spleen sizes were compared between groups.

Results

Of the 121 participants included in this study, 52 patients were HVs, 52 patients were PV and/or ET patients, and 17 patients were SMF patients. In terms of age and sex, there was no difference between groups. Splenic parenchymal stiffness median values by using SWE were found to be 0.82 m/s in HVs, 1.41 m/s in PV/ET patients, and 2.32 m/s in SMF patients (P < 0.001). In terms of median length of the spleen, the difference between groups was significant (P < 0.001). In addition, we found a significant positive correlation between spleen stiffness and bone marrow fibrosis degree (P < 0.001, r = 0.757). However, in multivariate analysis, there was no strong independent risk factor for spleen stiffness.

Conclusion

In this study, we showed that measurement of spleen stiffness using SWE can distinguish SMF from PV/ET patients and HVs. Therefore, we believe that SWE may be used as a noninvasive and easily accessible method to check the fibrotic progression of bone marrow in PV and ET patients to monitor the transformation to SMF, and enables to detect fibrosis in early phase.
Biomechanical Cervical Assessment Using 2-Dimentional Transvaginal Shear Wave Elastography in Nonpregnant and Pregnant Women
Authors: Zhang Man , Townsel Courtney D. , Akers Lindsay B. , Kiros Leah , Treadwell Marjorie C. , Maturen Katherine E.
Published: May 2021

This study evaluated the technical feasibility of 2-dimensional transvaginal shear wave elastography to quantify cervical stiffness in nonpregnant and pregnant women and established normal values in each group. With institutional review board approval, we performed a prospective study with an age-matched historical control design. Sixteen premenopausal nonpregnant women without cervical pathology and 17 low-risk pregnant women (gestational age 17–33 weeks) were enrolled. Cervical shear wave speeds were measured on a SuperSonic Aixplorer machine. The mean shear wave speeds of anterior cervix were 4.96 ± 1.96 m/s in nonpregnant women and 1.92 ± 0.31 m/s in pregnant women. No significant stiffness difference was found between the anterior and posterior cervix (P = 0.15). The upper cervix was stiffer than the lower cervix in the pregnant women (P = 0.00012). Transvaginal shear wave elastography reveals that cervix at a midterm gestation is significantly softer than nonpregnant cervix (P < 0.0001) and suggests a spatial stiffness gradient along the length of the cervix, consistent with histopathology and limited elastography literature. Our results indicate the potential of transvaginal shear wave elastography to provide objective and quantitative estimates of cervical stiffness, especially during pregnancy.
Efficacy of Shear Wave Elastography in the Differentiation of Acute and Subacute Deep Venous Thrombosis
Authors: Durmaz Fatma , Gultekin Mehmet Ali
Published: May 2021

It is important to know the age of clot formation to determine an appropriate treatment for deep vein thrombosis (DVT). The present study aims to differentiate between acute and subacute DVT using the shear wave elastography (SWE) technique. Patients with complaints no longer than 4 weeks and who were found to have early-stage (acute-subacute) thrombus on ultrasound (US) between January 2020 and May 2020 were included in the study. All of the patients underwent SWE using a Philips Healthcare EPIQ 5 Ultrasound System Inc. device with a high-resolution linear US probe (eL18-4, 22–2 MHz). Included in the study were 50 patients, including 23 with acute DVT and 27 with subacute DVT. Of the patients, 22 were women and 28 were men, and the mean age was 46.32 ± 11.33 years (range: 24–74 years). The mean SWE value was 2.63± 0.16 (2.39–2.96) in patients with acute DVT and 3.34± 0.31 (2.65–3.88) in patients with subacute DVT. The findings were statistically significant in the comparison of the 2 groups using an independent samples t test (P < 0.001). In the receiver operating characteristic analysis, the area under the curve was found to be 97.6%. When the cutoff value was taken as 2.85 according to the area under the curve, sensitivity was found to be 96.3%, and specificity was 91.3%. Thrombus stage plays a critical role in treatment decisions in DVT in the lower extremities. The present study reveals that the shear wave US elastography technique can be used to discriminate between acute and subacute DVT.
Obstructed Defecation Symptom Severity and Degree of Rectal Hypermobility and Folding Detected by Dynamic Ultrasound
Authors: Routzong Megan R. , Abramowitch Steven D. , Chang Cecilia , Goldberg Roger P. , Rostaminia Ghazaleh
Published: May 2021

We used dynamic pelvic floor ultrasound to investigate the relationship between obstructed defecation symptom (ODS) severity and the degree of rectal hypermobility/folding. In this retrospective study, women who presented with ODS from October 2017 to January 2019 and underwent an interview, pelvic examination, and pelvic floor ultrasound were recruited. Patients were diagnosed with abdominal constipation, dyssynergia, or pelvic constipation. Pelvic constipation patients were categorized based on their reported frequency of incomplete emptying of stool (<50% or ≥50% of bowel movements) representing mild and severe ODS, respectively. Using dynamic ultrasound, rectal hypermobility was quantified via rectovaginal septum length at rest and Valsalva and its compression ratio, where shorter lengths and larger compression ratios are indicative of increased rectal hypermobility. One hundred twenty-one patients (41 with abdominal constipation, 7 with dyssynergia, and 73 with pelvic constipation) were included. Compression ratios were higher in women with severe versus mild ODS (17.36 ± 16.89 vs 36.38 ± 25.82, P = 0.0039). The risk of having severe symptoms was 4 times greater (odds ratio = 4.2, 95% confidence interval = 1.4 to 12.6, P = 0.01) among those with a high compression ratio (≥20%) after controlling for age, body mass index, and levator plate descent angle. Incomplete emptying was weakly, positively, linearly correlated with rectal hypermobility/folding (r = −0.2724, −0.3767 to 0.3922, and P = 0.0197, 0.0010, 0.0006, respectively). Women with more severe ODS experienced more rectal hypermobility/folding as measured via dynamic ultrasound—a cheaper, effective alternative to magnetic resonance defecography for evaluation of obstructed defecation.
Interobserver Agreement Between Primary Sonographers and Secondary Overreaders for Screening and Surveillance Liver Ultrasounds Using Ultrasound Liver Imaging Reporting and Data System
Authors: Dawkins Adrian , Nelson Leslie W. , Gulati Vaibhav , Stepp Angela , Chapelin Fanny , Khurana Aman
Published: May 2021

The authors aim to identify if primary sonographers and secondary reviewers, both radiologists and sonographers, are likely to assign the same Ultrasound Liver Imaging Reporting and Data System (US LI-RADS) scores for liver surveillance ultrasounds. Institutional review board approval was obtained. Sonographers were familiarized with US LI-RADS via radiologist-led lectures. Three sonographers prospectively scored 170 screening examinations using US LI-RADS recommendations. Scans were retrospectively rescored by a fourth sonographer and a radiologist, both of whom were blinded to the original scores. Results were analyzed with weighted and nonweighted Cohen kappa statistical analysis methods. There was near-perfect agreement between primary and secondary sonographers and primary sonographer and radiologist (kappa of 0.87 and 0.92, respectively) for US LI-RADS category (cat) scores. However, only substantial and moderate agreements were noted for visualization (vis) scores between primary and secondary sonographers and primary sonographer and radiologist (weighted kappa of 0.73 and 0.48, respectively). There was vis score disagreement between the primary sonographer and radiologist in 60 (35.3%) cases. In 35 (20%) cases, the radiologist assigned a lower/more conservative vis score. There was vis score disagreement between the primary and secondary reviewing sonographers in 30 (17.6%) cases. In 12 (7%) cases, the secondary sonographer assigned a more conservative vis score. Although a good degree of concordance was noted between the groups, radiologists will need to generate their own US LI-RADS scoring to accurately reflect their impression and appropriately steer management.
Ultrasound Studies of COVID-19–Positive Patients and Patient Under Investigation
Authors: Gawande Rakhee S. , Vadvala Harshna V. , Shan Alan , Sheth Sheila
Published: May 2021

This retrospective study shares our departmental experience of screening of ultrasound (US) requests, triaging of studies, and abbreviated US protocols implemented during the COVID-19 pandemic. For US studies requested in April and May 2020, the following data were collected: type of study, indication, COVID-19 status (positive or patient under investigation [PUI]), decision to perform study, US findings, and location of patient. A total of 196 US studies in 150 patients were included. The median age of patients was 60 years (female: 46.7% [70/150]). At the time of study request, 83 patients (55.3%) were COVID-19–positive and 67 (44.7%) were PUI, of which 8 (11.9%) tested positive after waiting for test result. The most frequently requested study was venous extremity Doppler (51%), followed by right upper quadrant (20.4%), renal (11.7%), and liver duplex (6.6%). After radiologist screening and triage of US requests, 156 studies were performed (79.6%), 15 were postponed until COVID test result (7.6%), and 40 were not performed after discussion with ordering provider (20.4%). Notably, 40.1% of studies performed on COVID-19–positive patients yielded pathological findings, most frequently deep venous thrombosis (18.1%), medical renal disease (7.6%), and gall bladder sludge (5.7%). Abbreviated US protocols were used in 29.4% of studies. In conclusion, US study screening and triage played an important role to optimize care of COVID-19 patients and PUIs.
Use of Simulation to Visualize Healthcare Worker Exposure to Aerosol in the Operating Room
Authors: Frauenfelder Claire , Hall Andrew , Walsh Bill , Ross Alasdair , Broughton Emma , Hynds Robert E. , Nandi Reema , O'Callaghan Christopher , Butler Colin R.
Published: May 2021

Summary Statement

Simulation resources offer an opportunity to highlight aerosol dispersion within the operating room environment. We demonstrate our methodology with a supporting video that can offer operating room teams support in their practical understanding of aerosol exposure and the importance of personal protective equipment.
Circulating Donor Lung-specific Exosome Profiles Enable Noninvasive Monitoring of Acute Rejection in a Rodent Orthotopic Lung Transplantation Model
Authors: Habertheuer Andreas , Ram Chirag , Schmierer Maggie , Chatterjee Shampa , Hu Robert , Freas Andrew , Zielinski Patrick , Rogers Wade , Silvestro Eva M. , McGrane Michael , Moore Jonni S. , Korutla Laxminarayana , Siddiqui Sarmad , Xin Yi , Rizi Rahim , Qin Tao Jian , Kreisel Daniel , Naji Ali , Ochiya Takahiro , Vallabhajosyula Prashanth
Published: May 2021

Background.

There is a critical need for development of biomarkers to noninvasively monitor for lung transplant rejection. We investigated the potential of circulating donor lung-specific exosome profiles for time-sensitive diagnosis of acute rejection in a rat orthotopic lung transplant model.

Methods.

Left lungs from Wistar transgenic rats expressing human CD63-GFP, an exosome marker, were transplanted into fully MHC-mismatched Lewis recipients or syngeneic controls. Recipient blood was collected between 4 h and 10 d after transplantation, and plasma was processed for exosome isolation by size exclusion column chromatography and ultracentrifugation. Circulating donor exosomes were profiled using antihuman CD63 antibody quantum dot on the nanoparticle detector and via GFP trigger on the nanoparticle flow cytometer.

Results.

In syngeneic controls, steady-state levels of circulating donor exosomes were detected at all posttransplant time points. Allogeneic grafts lost perfusion by day 8, consistent with acute rejection. Levels of circulating donor exosomes peaked on day 1, decreased significantly by day 2, and then reached baseline levels by day 3. Notably, decrease in peripheral donor exosome levels occurred before grafts had histological evidence of acute rejection.

Conclusions.

Circulating donor lung-specific exosome profiles enable an early detection of acute rejection before histologic manifestation of injury to the pulmonary allograft. As acute rejection episodes are a major risk factor for the development of chronic lung allograft dysfunction, this biomarker may provide a novel noninvasive diagnostic platform that can translate into earlier therapeutic intervention for lung transplant patients.
Early childhood trauma, substance use and complex concurrent disorders among adolescents
Authors: Cabanis Maurice , Outadi Ava , Choi Fiona
Published: May 2021

Purpose of review

To highlight the interdependence between early childhood trauma, substance use and complex concurrent disorders among adolescents and discuss the delayed response and gaps in the healthcare system.

Recent findings

High-risk behavior such as suicidality, self-harm and hazardous substance use including overdose and the use of psychotropic substances for self-medication of mental health challenges is a growing concern. These symptoms are often related to early childhood trauma, substance use and complex concurrent disorders. Most countries do not have a youth mental healthcare system, there are no specific guidelines and only few programs addressing high-risk substance use are in place.

In addition to the significance of traumatic experience for high-risk substance use and addiction, most parts of the system of care ignore the trauma aspect in treatment of substance use and focus on abstinence. There are hardly any early intervention programs, broader prevention strategies or evidence-based or target-group-oriented treatment offers.
Digging the channels of inheritance: On how to distinguish between cultural and biological inheritance
Authors: Kronfeldner Maria
Published: May 2021

Theories of cultural evolution rest on the assumption that cultural inheritance is distinct from biological inheritance. Cultural and biological inheritance are two separate so-called channels of inheritance, two sub-systems of the sum total of developmental resources travelling in distinct ways between individual agents. This paper asks:what justifies this assumption?In reply, a philosophical account is offered that points at three related but distinct criteria that (taken together) make the distinction between cultural and biological inheritance not only precise but also justify it as real, i.e. as ontologically adequate. These three criteria are (i) the autonomy of cultural change, (ii) the near-decomposability of culture and (iii) differences in temporal order between cultural and biological inheritance.

This article is part of the theme issue ‘Foundations of cultural evolution’.
Culture, humanities, evolution: the complexity of meaning-making over time
Authors: Leerssen Joep
Published: May 2021

This article outlines how the historical human sciences see ‘culture’ and its dynamic developments over time and over generations. The operations of human culture are systemically self-reflexive and, as a result, exhibit a complexity that sets them apart, as a semiotic system, from mere communicative information transfer. Peculiar to this complexity is the two-way interaction between the ‘etic’ substance of the cultural exchanges and their ‘emic’ function. Cultural signals require parallel etic/emic processing at stacked levels of complexity. As a result of this complexity, the homeostasis and autopoiesis of human culture, including its dynamics and development over time, cannot be explained fully in terms of responses to the physical environment. How, this article ponders by way of conclusion, can an evolutionary approach be reconciled with these characteristics of human culture, or the notion of culture be applied to evolutionary modelling?

This article is part of the theme issue ‘Foundations of cultural evolution’.
Modelling cultural systems and selective filters
Authors: Jansson Fredrik , Aguilar Elliot , Acerbi Alberto , Enquist Magnus
Published: May 2021

A specific goal of the field of cultural evolution is to understand how processes of transmission and selection at the individual level lead to population-wide patterns of cultural diversity and change. Models of cultural evolution have typically assumed that traits are independent of one another and essentially exchangeable. But culture has a structure: traits bear relationships to one another that affect the transmission and selection process itself. Here, we introduce a modelling framework to explore the effect of interdependencies on the process of learning. Through simulations, we find that introducing a simple structure changes the cultural dynamics. Based on a basic filtering mechanism for parsing trait relationships, more elaborate cultural filters emerge. In a mostly incompatible cultural domain of traits, these filters organize culture into mostly (but not fully) consistent and stable systems. Incompatible domains produce small homogeneous cultures, while more compatibility increases size, diversity and group divergence. When individuals copy based on a trait’s features (here, its compatibility relationships), they produce more homogeneous cultures than when they copy based on the agent carrying the cultural trait. We discuss the implications of considering cultural systems and filters in the dynamics of cultural change.

This article is part of the theme issue ‘Foundations of cultural evolution’.
The cultural evolution and ecology of institutions
Authors: Currie Thomas E. , Campenni Marco , Flitton Adam , Njagi Tim , Ontiri Enoch , Perret Cedric , Walker Lindsay
Published: May 2021

Human societies are structured by what we refer to as ‘institutions’, which are socially created and culturally inherited proscriptions on behaviour that define roles and set expectations about social interactions. The study of institutions in several social science fields has provided many important insights that have not been fully appreciated in the evolutionary human sciences. However, such research has often lacked a shared understanding of general processes of change that shape institutional diversity across space and time. We argue that evolutionary theory can provide a useful framework for synthesizing information from different disciplines to address issues such as how and why institutions change over time, how institutional rules co-evolve with other culturally inherited traits, and the role that ecological factors might play in shaping institutional diversity. We argue that we can gain important insights by applying cultural evolutionary thinking to the study of institutions, but that we also need to expand and adapt our approaches to better handle the ways that institutions work, and how they might change over time. In this paper, we illustrate our approach by describing macro-scale empirical comparative analyses that demonstrate how evolutionary theory can be used to generate and test hypotheses about the processes that have shaped some of the major patterns we see in institutional diversity over time and across the world today. We then go on to discuss how we might usefully develop micro-scale models of institutional change by adapting concepts from game theory and agent-based modelling. We end by considering current challenges and areas for future research, and the potential implications for other areas of study and real-world applications.

This article is part of the theme issue ‘Foundations of cultural evolution’.
The evolution of social learning as phenotypic cue integration
Authors: Kuijper Bram , Leimar Olof , Hammerstein Peter , McNamara John M. , Dall Sasha R. X.
Published: May 2021

Most analyses of the origins of cultural evolution focus on when and where social learning prevails over individual learning, overlooking the fact that there are other developmental inputs that influence phenotypic fit to the selective environment. This raises the question of how the presence of other cue ‘channels’ affects the scope for social learning. Here, we present a model that considers the simultaneous evolution of (i) multiple forms of social learning (involving vertical or horizontal learning based on either prestige or conformity biases) within the broader context of other evolving inputs on phenotype determination, including (ii) heritable epigenetic factors, (iii) individual learning, (iv) environmental and cascading maternal effects, (v) conservative bet-hedging, and (vi) genetic cues. In fluctuating environments that are autocorrelated (and hence predictable), we find that social learning from members of the same generation (horizontal social learning) explains the large majority of phenotypic variation, whereas other cues are much less important. Moreover, social learning based on prestige biases typically prevails in positively autocorrelated environments, whereas conformity biases prevail in negatively autocorrelated environments. Only when environments are unpredictable or horizontal social learning is characterized by an intrinsically low information content, other cues such as conservative bet-hedging or vertical prestige biases prevail.

This article is part of the theme issue ‘Foundations of cultural evolution’.
Not by transmission alone: the role of invention in cultural evolution
Authors: Perry Susan , Carter Alecia , Smolla Marco , Akçay Erol , Nöbel Sabine , Foster Jacob G. , Healy Susan D.
Published: May 2021

Innovation—the combination of invention and social learning—can empower species to invade new niches via cultural adaptation. Social learning has typically been regarded as the fundamental driver for the emergence of traditions and thus culture. Consequently, invention has been relatively understudied outside the human lineage—despite being the source of new traditions. This neglect leaves basic questions unanswered: what factors promote the creation of new ideas and practices? What affects their spread or loss? We critically review the existing literature, focusing on four levels of investigation: traits (what sorts of behaviours are easiest to invent?), individuals (what factors make some individuals more likely to be inventors?), ecological contexts (what aspects of the environment make invention or transmission more likely?), and populations (what features of relationships and societies promote the rise and spread of new inventions?). We aim to inspire new research by highlighting theoretical and empirical gaps in the study of innovation, focusing primarily on inventions in non-humans. Understanding the role of invention and innovation in the history of life requires a well-developed theoretical framework (which embraces cognitive processes) and a taxonomically broad, cross-species dataset that explicitly investigates inventions and their transmission. We outline such an agenda here.

This article is part of the theme issue ‘Foundations of cultural evolution’.
Beyond social learning
Authors: Singh Manvir , Acerbi Alberto , Caldwell Christine A. , Danchin Étienne , Isabel Guillaume , Molleman Lucas , Scott-Phillips Thom , Tamariz Monica , van den Berg Pieter , van Leeuwen Edwin J. C. , Derex Maxime
Published: May 2021

Cultural evolution requires the social transmission of information. For this reason, scholars have emphasized social learning when explaining how and why culture evolves. Yet cultural evolution results from many mechanisms operating in concert. Here, we argue that the emphasis on social learning has distracted scholars from appreciating both the full range of mechanisms contributing to cultural evolution and how interactions among those mechanisms and other factors affect the output of cultural evolution. We examine understudied mechanisms and other factors and call for a more inclusive programme of investigation that probes multiple levels of the organization, spanning the neural, cognitive-behavioural and populational levels. To guide our discussion, we focus on factors involved in three core topics of cultural evolution: the emergence of culture, the emergence of cumulative cultural evolution and the design of cultural traits. Studying mechanisms across levels can add explanatory power while revealing gaps and misconceptions in our knowledge.

This article is part of the theme issue ‘Foundations of cultural evolution’.
Social information use and social information waste
Authors: Morin Olivier , Jacquet Pierre Olivier , Vaesen Krist , Acerbi Alberto
Published: May 2021

Social information is immensely valuable. Yet we waste it. The information we get from observing other humans and from communicating with them is a cheap and reliable informational resource. It is considered the backbone of human cultural evolution. Theories and models focused on the evolution of social learning show the great adaptive benefits of evolving cognitive tools to process it. In spite of this, human adults in the experimental literature use social information quite inefficiently: they do not take it sufficiently into account. A comprehensive review of the literature on five experimental tasks documented 45 studies showing social information waste, and four studies showing social information being over-used. These studies cover ‘egocentric discounting’ phenomena as studied by social psychology, but also include experimental social learning studies. Social information waste means that human adults fail to give social information its optimal weight. Both proximal explanations and accounts derived from evolutionary theory leave crucial aspects of the phenomenon unaccounted for: egocentric discounting is a pervasive effect that no single unifying explanation fully captures. Cultural evolutionary theory's insistence on the power and benefits of social influence is to be balanced against this phenomenon.

This article is part of the theme issue ‘Foundations of cultural evolution’.
Cultural selection and biased transformation: two dynamics of cultural evolution
Authors: Mesoudi Alex
Published: May 2021

Here, I discuss two broad versions of human cultural evolution which currently exist in the literature and which emphasize different underlying dynamics. One, which originates in population-genetic-style modelling, emphasizes how
cultural selection
causes some cultural variants to be favoured and gradually increase in frequency over others. The other, which draws more from cognitive science, holds that cultural change is driven by the
biased transformation
of cultural variants by individuals in non-random and consistent directions. Despite claims that cultural evolution is characterized by one or the other of these dynamics, these are neither mutually exclusive nor a dichotomy. Different domains of human culture are likely to be more or less strongly weighted towards cultural selection or biased transformation. Identifying cultural dynamics in real-world cultural data is challenging given that they can generate the same population-level patterns, such as directional change or cross-cultural stability, and the same cognitive and emotional mechanisms may underlie both cultural selection and biased transformation. Nevertheless, fine-grained historical analysis and laboratory experiments, combined with formal models to generate quantitative predictions, offer the best way of distinguishing them.

This article is part of the theme issue ‘Foundations of cultural evolution’.
The uses and abuses of tree thinking in cultural evolution
Authors: Evans Cara L. , Greenhill Simon J. , Watts Joseph , List Johann-Mattis , Botero Carlos A. , Gray Russell D. , Kirby Kathryn R.
Published: May 2021

Modern phylogenetic methods are increasingly being used to address questions about macro-level patterns in cultural evolution. These methods can illuminate the unobservable histories of cultural traits and identify the evolutionary drivers of trait change over time, but their application is not without pitfalls. Here, we outline the current scope of research in cultural tree thinking, highlighting a toolkit of best practices to navigate and avoid the pitfalls and ‘abuses' associated with their application. We emphasize two principles that support the appropriate application of phylogenetic methodologies in cross-cultural research: researchers should (1) draw on multiple lines of evidence when deciding if and which types of phylogenetic methods and models are suitable for their cross-cultural data, and (2) carefully consider how different cultural traits might have different evolutionary histories across space and time. When used appropriately phylogenetic methods can provide powerful insights into the processes of evolutionary change that have shaped the broad patterns of human history.

This article is part of the theme issue ‘Foundations of cultural evolution'.
The potential to infer the historical pattern of cultural macroevolution
Authors: Lukas Dieter , Towner Mary , Borgerhoff Mulder Monique
Published: May 2021

Phylogenetic analyses increasingly take centre-stage in our understanding of the processes shaping patterns of cultural diversity and cultural evolution over time. Just as biologists explain the origins and maintenance of trait differences among organisms using phylogenetic methods, so anthropologists studying cultural macroevolutionary processes use phylogenetic methods to uncover the history of human populations and the dynamics of culturally transmitted traits. In this paper, we revisit concerns with the validity of these methods. Specifically, we use simulations to reveal how properties of the sample (size, missing data), properties of the tree (shape) and properties of the traits (rate of change, number of variants, transmission mode) might influence the inferences that can be drawn about trait distributions across a given phylogeny and the power to discern alternative histories. Our approach shows that in two example datasets specific combinations of properties of the sample, of the tree and of the trait can lead to potentially high rates of Type I and Type II errors. We offer this simulation tool to help assess the potential impact of this list of persistent perils in future cultural macroevolutionary work.

This article is part of the theme issue ‘Foundations of cultural evolution’.
Historical, archaeological and linguistic evidence test the phylogenetic inference of Viking-Age plant use
Authors: Teixidor-Toneu Irene , Kool Anneleen , Greenhill Simon J. , Kjesrud Karoline , Sandstedt Jade J. , Manzanilla Vincent , Jordan Fiona M.
Published: May 2021

In this paper, past plant knowledge serves as a case study to highlight the promise and challenges of interdisciplinary data collection and interpretation in cultural evolution. Plants are central to human life and yet, apart from the role of major crops, people–plant relations have been marginal to the study of culture. Archaeological, linguistic, and historical evidence are often limited when it comes to studying the past role of plants. This is the case in the Nordic countries, where extensive collections of various plant use records are absent until the 1700s. Here, we test if relatively recent ethnobotanical data can be used to trace back ancient plant knowledge in the Nordic countries. Phylogenetic inferences of ancestral states are evaluated against historical, linguistic, and archaeobotanical evidence. The exercise allows us to discuss the opportunities and shortcomings of using phylogenetic comparative methods to study past botanical knowledge. We propose a ‘triangulation method’ that not only combines multiple lines of evidence, but also quantitative and qualitative approaches.

This article is part of the theme issue ‘Foundations of cultural evolution’.
Underappreciated features of cultural evolution
Authors: Smolla Marco , Jansson Fredrik , Lehmann Laurent , Houkes Wybo , Weissing Franz J. , Hammerstein Peter , Dall Sasha R. X. , Kuijper Bram , Enquist Magnus
Published: May 2021

Cultural evolution theory has long been inspired by evolutionary biology. Conceptual analogies between biological and cultural evolution have led to the adoption of a range of formal theoretical approaches from population dynamics and genetics. However, this has resulted in a research programme with a strong focus on cultural transmission. Here, we contrast biological with cultural evolution, and highlight aspects of cultural evolution that have not received sufficient attention previously. We outline possible implications for evolutionary dynamics and argue that not taking them into account will limit our understanding of cultural systems. We propose 12 key questions for future research, among which are calls to improve our understanding of the combinatorial properties of cultural innovation, and the role of development and life history in cultural dynamics. Finally, we discuss how this vibrant research field can make progress by embracing its multidisciplinary nature.

This article is part of the theme issue ‘Foundations of cultural evolution’.
Missing data matters in participatory syndromic surveillance systems: comparative evaluation of missing data methods when estimating disease burden
Authors: Baltrusaitis Kristin , Dalton Craig , Carlson Sandra , White Laura F.
Published: May 2021

Introduction

Traditional surveillance methods have been enhanced by the emergence of online participatory syndromic surveillance systems that collect health-related digital data. These systems have many applications including tracking weekly prevalence of Influenza-Like Illness (ILI), predicting probable infection of Coronavirus 2019 (COVID-19), and determining risk factors of ILI and COVID-19. However, not every volunteer consistently completes surveys. In this study, we assess how different missing data methods affect estimates of ILI burden using data from FluTracking, a participatory surveillance system in Australia.

Methods

We estimate the incidence rate, the incidence proportion, and weekly prevalence using five missing data methods: available case, complete case, assume missing is non-ILI, multiple imputation (MI), and delta (δ) MI, which is a flexible and transparent method to impute missing data under Missing Not at Random (MNAR) assumptions. We evaluate these methods using simulated and FluTracking data.

Results

Our simulations show that the optimal missing data method depends on the measure of ILI burden and the underlying missingness model. Of note, the δ-MI method provides estimates of ILI burden that are similar to the true parameter under MNAR models. When we apply these methods to FluTracking, we find that the δ-MI method accurately predicted complete, end of season weekly prevalence estimates from real-time data.

Conclusion

Missing data is an important problem in participatory surveillance systems. Here, we show that accounting for missingness using statistical approaches leads to different inferences from the data.
Identification of translocation inhibitors targeting the type III secretion system of enteropathogenic Escherichia coli
Authors: Mühlen Sabrina , Zapol’skii Viktor A. , Bilitewski Ursula , Dersch Petra
Published: May 2021

Infections with enteropathogenic E. coli (EPEC) cause severe diarrhea in children. The non-invasive bacteria adhere to enterocytes of the small intestine and use a type III secretion system (T3SS) to inject effector proteins into host cells to modify and exploit cellular processes in favor of bacterial survival and replication. Several studies have shown that the T3SSs of bacterial pathogens are essential for virulence. Furthermore, the loss of T3SS-mediated effector translocation results in increased immune recognition and clearance of the bacteria. The T3SS is, therefore, considered a promising target for antivirulence strategies and novel therapeutics development. Here, we report the results of a high-throughput screening assay based on the translocation of the EPEC effector protein Tir. Using this assay, we screened more than 13,000 small molecular compounds of six different compound libraries and identified three substances which showed a significant dose-dependent effect on translocation without adverse effects on bacterial or eukaryotic cell viability. Additionally, these substances reduced bacterial binding to host cells, effector-dependent cell detachment and abolished A/E lesion formation without affecting the expression of components of the T3SS or associated effector proteins. Moreover, no effects of the inhibitors on bacterial motility or Shiga-toxin expression were observed. In summary, we have identified three new compounds that strongly inhibit T3SS-mediated translocation of effectors into mammalian cells, which could be valuable as lead substances for treating EPEC and EHEC infections.
Determinants and trends of COVID-19 vaccine hesitancy and vaccine uptake in a national cohort of U.S. adults: A longitudinal study
Authors: Rane Madhura S. , Kochhar Shivani , Poehlein Emily , You William , Robertson McKaylee M. , Zimba Rebecca , Westmoreland Drew A. , Romo Matthew L. , Kulkarni Sarah G. , Chang Mindy , Berry Amanda , Parcesepe Angela M. , Maroko Andrew R. , Grov Christian , Nash Denis ,   the CHASING COVID Cohort Study Team
Published: May 2021

We estimated the trends and correlates of vaccine hesitancy, and its association with subsequent vaccine uptake among 5,458 adults in the United States. Participants belonged to the CHASING COVID Cohort, a national longitudinal study. Trends and correlates of vaccine hesitancy were examined longitudinally in eight interview rounds from October 2020 to July 2021. We also estimated the association between willingness to vaccinate and subsequent vaccine uptake through July 2021. Vaccine delay and refusal decreased from 51% and 8% in October 2020 to 8% and 6% in July 2021, respectively. Compared to Non-Hispanic (NH) White participants, NH Black and Hispanic participants had higher adjusted odds ratios (aOR) for both vaccine delay (aOR: 2.0 [95% CI: 1.5, 2.7] for NH Black and 1.3 [95% CI: 1.0, 1.7] for Hispanic) and vaccine refusal (aOR: 2.5 [95% CI: 1.8, 3.6] for NH Black and 1.4 [95% CI: 1.0, 2.0] for Hispanic) in June 2021. COVID-19 vaccine hesitancy was associated with lower odds of subsequent vaccine uptake (aOR: 0.15, 95% CI: 0.13, 0.18 for vaccine-delayers and aOR: 0.02; 95% CI: 0.01, 0.03 for vaccine-refusers compared to vaccine-willing participants), adjusted for sociodemographic factors and COVID-19 history. Vaccination awareness and distribution efforts should focus on vaccine delayers.
Bayesian Model Averaging to Account for Model Uncertainty in Estimates of a Vaccine’s Effectiveness
Authors: Oliveira Carlos R , Shapiro Eugene D , Weinberger Daniel M
Published: May 2021

Vaccine effectiveness (VE) studies are often conducted after the introduction of new vaccines to ensure they provide protection in real-world settings. Although susceptible to confounding, the test-negative case-control study design is the most efficient method to assess VE post-licensure. Control of confounding is often needed during the analyses, which is most efficiently done through multivariable modeling. When a large number of potential confounders are being considered, it can be challenging to know which variables need to be included in the final model. This paper highlights the importance of considering model uncertainty by re-analyzing a Lyme VE study using several confounder selection methods. We propose an intuitive Bayesian Model Averaging (BMA) framework for this task and compare the performance of BMA to that of traditional single-best-model-selection methods. We demonstrate how BMA can be advantageous in situations when there is uncertainty about model selection by systematically considering alternative models and increasing transparency.
SARS-CoV-2 testing strategies to contain school-associated transmission: model-based analysis of impact and cost of diagnostic testing, screening, and surveillance
Authors: Bilinski Alyssa , Ciaranello Andrea , Fitzpatrick Meagan C. , Giardina John , Shah Maunank , Salomon Joshua A. , Kendall Emily A.
Published: May 2021

Background

In March 2021, the Biden administration allocated $10 billion for COVID-19 testing in schools. We evaluate the costs and benefits of testing strategies to reduce the infection risks of full-time in-person K-8 education at different levels of community incidence.

Methods

We used an agent-based network model to simulate transmission in elementary and middle school communities, parameterized to a US school structure and assuming dominance of the delta COVID-19 variant. We assess the value of different strategies for testing students and faculty/staff, including expanded diagnostic testing (“test to stay” policies that take the place of isolation for symptomatic students or quarantine for exposed classrooms); screening (routinely testing asymptomatic individuals to identify infections and contain transmission); and surveillance (testing a random sample of students to signaling undetected transmission and trigger additional investigation or interventions).

Main outcome measures

We project 30-day cumulative incidence of SARS-CoV-2 infection; proportion of cases detected; proportion of planned and unplanned days out of school; and the cost of testing programs and of childcare costs associated with different strategies. For screening policies, we further estimate cost per SARS-CoV-2 infection averted in students and staff, and for surveillance, probability of correctly or falsely triggering an outbreak response at different incidence and attack rates.

Results

Accounting for programmatic and childcare costs, “test to stay” policies achieve similar model-projected transmission to quarantine policies, with reduced overall costs. Weekly universal screening prevents approximately 50% of in-school transmission, with a lower projected societal cost than hybrid or remote schooling. The cost per infection averted in students and staff by weekly screening is lower for older students and schools with higher mitigation and declines as community transmission rises. In settings where local student incidence is unknown or rapidly changing, surveillance may trigger detection of moderate-to-large in-school outbreaks with fewer resources compared to screening.

Conclusions

“Test to stay” policies and/or screening tests can facilitate consistent in-person school attendance with low transmission risk across a range of community incidence. Surveillance may be a useful reduced-cost option for detecting outbreaks and identifying school environments that may benefit from increased mitigation.