Quantifying hierarchy and prestige in US ballet academies as social predictors of career success.

In the recent decade, we have seen major progress in quantifying the behaviors and the impact of scientists, resulting in a quantitative toolset capable of monitoring and predicting the career patterns of the profession. It is unclear, however, if this toolset applies to other creative domains beyond the sciences. In particular, while performance in the arts has long been difficult to quantify objectively, research suggests that professional networks and prestige of affiliations play a similar role to those observed in science, hence they can reveal patterns underlying successful careers. To test this hypothesis, here we focus on ballet, as it allows us to investigate in a quantitative fashion the interplay of individual performance, institutional prestige, and network effects. We analyze data on competition outcomes from 6363 ballet students affiliated with 1603 schools in the United States, who participated in the Youth America Grand Prix (YAGP) between 2000 and 2021. Through multiple logit models and matching experiments, we provide evidence that schools' strategic network position bridging between communities captures social prestige and predicts the placement of students into jobs in ballet companies. This work reveals the importance of institutional prestige on career success in ballet and showcases the potential of network science approaches to provide quantitative viewpoints for the professional development of careers beyond science.

Muerte súbita y secuenciación de siguiente generación. Revisión bibliográfica / Sudden death and next generation sequencing. A review

Introducción: la muerte súbita se trata de un evento fatal e imprevisible. Realizada la autopsia y estudios complementarios, en ausencia de otros hallazgos que expliquen la causa de muerte, se clasifica como muerte súbita inexplicada. Siendo recomendable en estos casos realizar análisis genéticos, especialmente con metodologías de secuenciación de siguiente generación, las que permiten explicar un porcentaje importante de estos casos. Objetivo: analizar las publicaciones más relevantes sobre secuenciación de siguiente generación, aplicada a la autopsia molecular, para determinar aquellas muertes súbitas inexplicables relacionadas a cardiomiopatías y canalopatías. Metodología: se realizó la búsqueda en PubMed del Instituto Nacional de Salud usando palabras clave en inglés y español: NGS, muerte súbita, autopsia molecular y sus combinaciones. Además, se realizaron búsquedas en OMIN y ClinVar relacionada a las diferentes afecciones cardiacas relacionadas a muerte súbita. Los criterios de inclusión: artículos completos en español e inglés de libre acceso, con antigüedad máxima de diez años, realizados en cualquier área geográfica y que trataran sobre la temática. Resultados: para secuenciación de siguiente generación, muerte súbita se encontraron más de 22000 y 65000 publicaciones, respectivamente. En cambio, al combinar las palabras clave se recuperaron 74 trabajos, según los criterios de inclusión y objetivo del trabajo se revisaron 67 artículos. La aplicación de las plataformas de secuenciación en la investigación de casos de muerte súbita tomo auge en el 2014 y en poco tiempo, demostraron su versatilidad para el análisis de una gran cantidad de genes simultáneamente, de forma rápida y a bajo costo. Conclusiones: las patologías asociadas a muerte súbita son múltiples, complejas y pueden generar fenotipos variables que dificultan el análisis genético de las mismas. Las plataformas de secuenciación de siguiente generación son sumamente útiles en los casos de muerte súbita inexplicada, además permiten la identificación de variantes genéticas en familiares para la implementación de medidas preventivas...(AU)

Reciprocity heightens academic performance in elementary school students.

Social relationships are pivotal for human beings. Yet, we still lack a complete understanding of the types and conditions of social relationships that facilitate learning among children. Here, we present the results of a study involving 855 elementary school children from 14 different public schools in Chile designed to understand their social learning strategies in classrooms. We mapped students' social relationships using a behavioral experiment-a non-anonymous social dilemma-that allows us to measure cooperation and infer reciprocal and asymmetrical relationships between peers. We implemented the experiment synchronously in each classroom using networked tablets and a friendly user interface to mitigate cognitive barriers and boost students' engagement. Using regression models, we found a positive and significant association between reciprocity and academic performance. This result holds after controlling for class attendance, sex, parents' education, social status, individual cooperative dispositions, and fixed effects per class group. Finally, using a difference-in-difference framework, we found robust evidence that reciprocity heightens academic performance by comparing two consecutive academic semesters. This effect is heterogeneous and is considerably more prominent for the top 20% students experiencing higher levels of reciprocity in their social relationships. We expect these results to inform cooperative learning interventions in elementary education.

Citizens at the forefront of the constitutional debate: Voluntary citizen participation determinants and emergent content in Chile.

In the past few decades, constitution-making processes have shifted from being undertakings performed by elites and closed off from the public to ones incorporating democratic mechanisms. Little is known, however, about the determinants of voluntary public participation and how they affect the outcomes of the deliberative process in terms of content and quality. Here, we study the process of constituent involvement in the rewriting of Chile's constitution in 2016. A total of 106, 412 citizens in 8, 113 different local encounters voluntarily congregated in groups of ten or more to collectively determine what social rights should be considered for inclusion in the new constitution, deliberating and then articulating in the written word why should be included. We brought our data to statistical regression models at the municipality level, the results show that the main determinants associated with increasing citizen participation are educational level, engagement in politics, support for the government, and Internet access. In contrast, population density and the share of Evangelical Christians in the general population decrease citizen participation. Then, we further analyze the written arguments for each collectively-selected constitutional rights. The findings suggest that groups from socioeconomically developed municipalities (with higher educational levels and where the main economic activities are more distant from natural resources), on average, deliberate consistently more about themes, concepts, and ideas compared to groups from less developed municipalities. These results provide an empirical ground on the driver factors of voluntary citizen participation and on the benefits and disadvantages of deliberative democracy. Hence, results can inform the organization of new deliberative processes.

Trazas de ADN y su implicancia en la obtención de perfiles genéticos: revisión bibliográfica / Trace DNA and its implication in obtaining genetic profiles: bibliographic review

Introducción: El aumento en la sensibilidad de las técnicas empleadas ha permitido la obtención de perfiles genéticos a partir de trazas de ADN que se hayan depositado mediante contacto antes, durante o después de la comisión de los hechos investigados. Por otro lado, la contaminación accidental de los indicios biológicos, con la consecuente interpretación errónea de los resultados genéticos, tienen importantes consecuencias en el proceso judicial. Debido a ello, minimizar las contaminaciones que se pueden generar durante algunas de las fases de recolección o análisis genético, como así también la detección de estos eventos, es una prioridad para los laboratorios forenses. Objetivo: analizar las publicaciones más relevantes respecto a las trazas de ADN, los diferentes tipos de transferencia y contaminación que se pueden obtener en una evidencia. Metodología: se realizó la búsqueda en PubMed, del Instituto Nacional de Salud (NIH), y Google Académico usando las palabras clave en español e inglés: ADN de toque, Transferencia de ADN, Contaminación, Trazas, DNA-TTPR, Persistencia del ADN, Perfiles genéticos contaminados. Resultados: se encontraron más de 500 trabajos relacionados a la temática propuesta en esta revisión. El criterio de selección fue el número de citas, el enfoque y el impacto de estos. Se analizaron 71 artículos donde evaluaron la composición de las muestras de contacto y el origen del material genético que contienen. Además, de las metodologías de recolección, análisis de dichas muestras, la importancia que tiene la transferencia y contaminación del ADN en distintos escenarios posibles. Conclusión: existe riesgo de transferencia de ADN que puede conducir a resultados erróneos, por lo tanto es importante asegurar la actualización de los procedimientos de la práctica y brindar la capacitación adecuada para garantizar que el personal policial y del que recolecta indicios sea consciente de los riesgos de contaminación y de los diferentes mecanismos de transferencia de material genético...(AU)

Quantifying the selective forgetting and integration of ideas in science and technology.

How long will this article be remembered? How long will people reference it in their conversations, and for how many years will other authors cite its findings in their own works? A community's attention to a cultural object decays as time passes, a process known as collective forgetting. Recent work models this decay as the result of two different processes. One linked to communicative memory-memories sustained by human communication-and the other linked to cultural memory-memories sustained by the physical recording of content. Collective forgetting has significant impacts on communities, yet little is known about how the collective forgetting dynamic changes over time. Here, we study the temporal changes of collective memory and attention by focusing on two knowledge communities: inventors and physicists. We use data on patents from the United States Patent and Trademark Office (USPTO) and physics papers published by the American Physical Society (APS) to quantify those changes over time. The model enables us to distinguish between two branches of forgetting. One branch is short-lived, going directly from communicative memory to oblivion. The other branch is long-lived, going from communicative memory to cultural memory before going on to oblivion. The data analysis shows an increase in the forgetting rate for both communities as the amount of information in each of them grows. That growth of information forces knowledge communities to increase their selectivity regarding what is stored in their cultural memory. These findings confirm the forgetting as annulment hypothesis and show that knowledge communities can slow down collective forgetting and improve selectivity processes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Scaling behavior of public procurement activity.

Public procurement refers to the purchase by public sector entities-such as government departments or local authorities-of Services, Goods, or Works. It accounts for a significant share of OECD countries' expenditures. However, while governments are expected to execute them as efficiently as possible, there is a lack of methodologies for an adequate comparison of procurement activity between institutions at different scales, which represents a challenge for policymakers and academics. Here, we propose using methods borrowed from urban scaling laws literature to study public procurement activity among 278 Portuguese municipalities between 2011 and 2018. We find that public procurement expenditure scales sublinearly with population size, indicating an economy of scale for public spending as cities increase their population size. Moreover, when looking at the municipal Scale-Adjusted Indicators (the deviations from the scaling law) by contract categories-Works, Goods, and Services-we are able to identify a richer local characterisation of municipalities based on the similarity of procurement activity. These results make up a framework for quantitatively studying local public expenditure by enabling policymakers a more appropriate foundation for comparative analysis.

The universal decay of collective memory and attention.

Collective memory and attention are sustained by two channels: oral communication (communicative memory) and the physical recording of information (cultural memory). Here, we use data on the citation of academic articles and patents, and on the online attention received by songs, movies and biographies, to describe the temporal decay of the attention received by cultural products. We show that, once we isolate the temporal dimension of the decay, the attention received by cultural products decays following a universal biexponential function. We explain this universality by proposing a mathematical model based on communicative and cultural memory, which fits the data better than previously proposed log-normal and exponential models. Our results reveal that biographies remain in our communicative memory the longest (20-30 years) and music the shortest (about 5.6 years). These findings show that the average attention received by cultural products decays following a universal biexponential function.

Human immunodeficiency virus-1 BF intersubtype recombinant viral protein U second α helix plays an important role in viral release and BST-2 degradation.

We previously reported a naturally occurring BF intersubtype recombinant viral protein U (Vpu) variant with an augmented capacity to enhance viral replication. Structural analysis of this variant revealed that its transmembrane domain and α-helix I in the cytoplasmic domain (CTD) corresponded to subtype B, whereas the α-helix II in the CTD corresponded to subtype F1. In this study, we aimed to evaluate the role of the Vpu cytoplasmic α-helix II domain in viral release enhancement and in the down-modulation of BST-2 and CD4 from the cell surface. In addition, as serine residues in Vpu amino acid positions 61 or 64 have been shown to regulate Vpu intracellular half-life, which in turn could influence the magnitude of viral release, we also studied the impact of these residues on the VpuBF functions, since S61 and S64 are infrequently found among BF recombinant Vpu variants. Our results showed that the exchange of Vpu α-helix II between subtypes (B→F) directly correlated with the enhancement of viral release and, to a lesser extent, with changes in the capacity of the resulting chimera to down-modulate BST-2 and CD4. No differences in viral release and BST-2 down-modulation were observed between VpuBF and VpuBF-E61S. On the other hand, VpuBF-A64S showed a slightly reduced capacity to enhance viral production, but was modestly more efficient than VpuBF in down-modulating BST-2. In summary, our observations clearly indicate that α-helix II is actively involved in Vpu viral-release-promoting activity and that intersubtype recombination between subtypes B and F1 created a protein variant with a higher potential to boost the spread of the recombinant strain that harbours it.

Genetic and functional analysis of HIV type 1 nef gene derived from long-term nonprogressor children: association of attenuated variants with slow progression to pediatric AIDS.

Among persons infected by HIV-1, the rate of progression to AIDS is multifactorial being affected by host and viral factors, including the HIV-encoded negative factor (Nef). Our aim was to define whether variations in the nef gene as well as its functions may be associated with slower HIV disease course in infected children. The proviral HIV-1 nef gene was cloned, sequenced, and compared in children with contrasting disease course: 10 long-term nonprogressors (LTNP) and six rapid progressor (RP). The CD4 and MHC-I down-modulation ability of nef alleles derived from LTNP and RP children was analyzed. We observed that only one of our 10 LTNP had a protective genetic background, and out of them, 40% had defective nef genes, carrying substitutions at the (AWLEAQ(56-61)) and the (Rxx(22-24)) domains, and that those alleles were unable of down-regulate CD4 and MHC-I. The emergence or presence of Nef L58V substitution was associated with viral attenuation, indicated by a reduction in HIV viral loads, a persistent preservation of CD4(+) T cell counts, and lack of AIDS-related symptoms. Our results demonstrate that HIV-1 perinatally infected children carrying functionally defective nef HIV-1 strains have prolonged asymptomatic phases without therapy, suggesting a relevant role of CD4 and MHC-I down-modulation Nef domains on in vivo HIV-1 pathogenesis and pediatric immunodeficiency outcome.

HIV-mediated up-regulation of invariant chain (CD74) correlates with generalized immune activation in HIV+ subjects.

HIV Nef-mediated up-regulation of invariant chain (Ii chain, also CD74) is presumed to play an active role in HIV immunopathogenesis. However, this has not been definitely ascertained. In order to help elucidate this hypothesis, Ii chain, CD4, HLA-DR and HLA-ABC expression was analyzed ex vivo in monocyte-derived macrophages (MDMs) from HIV(+) subjects. Viral load, CD4(+) T cell count and immune activation were also determined in enrolled subjects. Correlations between these parameters and the modulation of cell surface molecules in infected cells were studied. Ii chain expression was found to be up-regulated in infected MDMs derived from all patients but one (median fold up-regulation 2.47±1.82 (range 0.87-7.36)). Moreover, the magnitude of Ii chain up-regulation significantly correlated with higher activation of B and CD4(+) T cells (studied by HLA-DR and CD38 expression). On the other hand, lower HLA-ABC (i.e. stronger down-regulation) in infected MDMs was associated with higher CD4 counts. No correlation was observed between the magnitude of Ii chain up-regulation and the other Nef functions studied here. This is the first study reporting that Ii chain up-regulation occurs on naturally infected antigen presenting cells obtained directly from HIV(+) subjects. Moreover, it is also shown that the magnitude of this up-regulation correlates with immune activation. This allows postulating an alternative hypothesis regarding the contribution of Ii chain up-regulation to HIV-mediated immune damage.

Viral replication is enhanced by an HIV-1 intersubtype recombination-derived Vpu protein.

BACKGROUND: Multiple HIV-1 intersubtype recombinants have been identified in human populations. Previous studies from our lab group have shown that the epidemic in Argentina is characterized by the high prevalence of a circulating recombinant form, CRF12_BF, and many related BF recombinant forms. In these genomic structures a recombination breakpoint frequently involved the vpu coding region. Due to the scarce knowledge of Vpu participation in the virion release process and its impact on pathogenesis and of the functional capacities of intersubtype recombinant Vpu proteins, the aim of this work was to perform a comparative analysis on virion release capacity and relative replication capacity among viral variants harboring either a BF recombinant Vpu or a subtype B Vpu. RESULTS: Our results showed that BF recombinant Vpu was associated to an increased viral particles production when compared to WT B variant in tetherin-expressing cell lines. This observation was tested in the context of a competition assay between the above mentioned variants. The results showed that the replication of the BF Vpu-harboring variant was more efficient in cell cultures than subtype B, reaching a higher frequency in the viral population in a short period of time. CONCLUSION: This study showed that as a result of intersubtype recombination, a structurally re-organized HIV-1 Vpu has an improved in vitro capacity of enhancing viral replication, and provides evidence of the changes occurring in this protein function that could play an important role in the successful spread of intersubtype recombinant variants.

In vitro dynamics of HIV-1 BF intersubtype recombinants genomic regions involved in the regulation of gene expression.

HIV-1 intersubtype recombination is a very common phenomenon that has been shown to frequently affect different viral genomic regions. Vpr and Tat are viral proteins known to interact with viral promoter (LTR) during the replication cycle. This interaction is mainly involved in the regulation of viral gene expression, so, any structural changes in the LTR and/or these regulatory proteins may have an important impact on viral replication and spread. It has been reported that these genetic structures underwent recombination in BF variants widely spread in South America. To gain more insight of the consequences of the BF intersubtype recombination phenomenon on these different but functionally related genomic regions we designed and performed and in vitro study that allowed the detection and recovery of intersubtype recombinants sequences and its subsequent analysis. Our results indicate that recombination affects differentially these regions, showing evidence of a time-space relationship between the changes observed in the viral promoter and the ones observed in the Vpr/Tat coding region. This supports the idea of intersubtype recombination as a mechanism that promotes biological adaptation and compensates fitness variations.