Locating the source of projectile fluid droplets

The ill-posed projectile problem of finding the source height from spattered droplets of viscous fluid is a longstanding obstacle to accident reconstruction and crime scene analysis. It is widely known how to infer the impact angle of droplets on a surface from the elongation of their impact profiles. However, the lack of velocity information makes finding the height of the origin from the impact position and angle of individual drops not possible. From aggregate statistics of the spatter and basic equations of projectile motion, we introduce a reciprocal correlation plot that is effective when the polar launch angle is concentrated in a narrow range. The vertical coordinate depends on the orientation of the spattered surface, and equals the tangent of the impact angle for a level surface. When the horizontal plot coordinate is twice the reciprocal of the impact distance, we can infer the source height as the slope of the data points in the reciprocal correlation plot. If the distribution of launch angles is not narrow, failure of the method is evident in the lack of linear correlation. We perform a number of experimental trials, as well as numerical calculations and show that the height estimate is insensitive to aerodynamic drag. Besides its possible relevance for crime investigation, reciprocal-plot analysis of spatter may find application to volcanism and other topics and is most immediately applicable for undergraduate science and engineering students in the context of crime-scene analysis.Comment: To appear in the American Journal of Physics (ms 23338). Improved readability and organization in this versio

Prevalencia de anticuerpos Anti-HTLV-I Y HTLV-II en donantes del banco de sangre del Hospital Regional de Talca

42 p.El virus linfotrópico humano (HTLV) es un retrovirus causante de la paraperesia espástica tropical y de la leucemia/linfoma de las células T humanas. Es cosmopolita, con mayor prevalencia en el Sur de Japón, en el Caribe y en nativos de América del Sur. En países que poseen tasas de transmisión altas, se ha implementado el tamizaje serológico obligatorio, pero existen países como Chile que posee una prevalencia de 1% en la población y no se considera como obligatorio el tamizaje para los bancos de sangre. Con el propósito de aportar en el estudio del riesgo de infecciones por HTLV I/II adquiridas por transfusión en Chile, se determina la presencia de anticuerpos anti HTLVI/ II, en el suero de 436 donantes de sangre del Hospital Regional de Talca, por medio de kit de ELISA Abbott. Encontrándose una seroprevalencia para esta área de 0.68%. Con esto se puede demostrar la importancia para justificar la ejecución de pruebas de tamizaje serológicas rutinariamente junto con otros patógenos determinados, como el VIH, Hepatitis B y C y sífilis. Dado que este porcentaje es relativamente alto, pero no fue posible realizar los estudios confirmatorios será necesario analizar la justificación de implementar el tamizaje serológico de este virus a todas las donaciones de sangre de este centro asistencial

Beyond (and Alongside) Shameful Attachments: The Lived Experience of Critique Within the Entrepreneurial University

This is the final version. Available on open access from SAGE Publications via the DOI in this recordDuring 2019, we embarked on a fieldwork based on 18 semi-structured interviews with international scholars in the humanities and social sciences in Chilean universities to explore their experiences with knowledge. Drawing on theories of critique and neoliberalism, we analyzed their ambivalent and unsettling conjunction of attachments to neoliberal and critical knowledge formations. By developing the notion of regime of epistemic subjectification, we emphasized the affective intensities these experiences brought to bear amid the differential weight and interplay of neoliberalism and critique as ethico-epistemic modes of engagement. We argued that the dominant focus on neoliberal knowledge and entrepreneurial subjectivity, albeit intense, expansive, and seemingly omnipresent, must be complicated by exposing its ambivalent affective and somatic force, and recognizing the difference between critical academic products and the lived experience of critique. The latter was constituted in the outsides of the inside of the neoliberal knowledge regime.University Alberto Hurtad

Crítica y utopía en los estudios sobre educación en América Latina: en contra de la osificación de la crítica

This is the final version. Available on open access from Instituto Internacional de Filosofía y Estudios Sociales via the link in this recor

The discursive formation of the affirmative action policy in Chile: Right to higher education, public education, and deficit

This is the final version. Available on open access from SAGE Publications via the DOI in this record. Global scholarly narratives have identified a strong influence of anti-racist, anti-discrimination, and gender equality movements and discourses on affirmative actions in higher education in different national contexts. While empirically valid for various cases, this portrait overlooks affirmative actions’ problematic entanglements with other conflictive rationalities and political projects. This article focused on the discursive formation of the affirmative action policy in Chile within a hegemonic context of meritocratic and neoliberal ideologies in higher education arrangements. It delves into a case that has been scarcely considered within the progressive narratives framing affirmative actions in higher education globally. Based on 61 policy documents and 16 interviews with key policy actors as part of a broader critical policy ethnography, we uncover three crucial contradictory and yet articulated discursive lines constituting this policy—higher education as a social right, recovery of public education, and deficit alongside key ideological policy technologies: situated meritocracy, improvement, and leveling. These discursive formations were associated with significant struggles and intertwinement with neoliberal higher education and reorientations at the State level. This work contributes to a more nuanced understanding of the discursive porosity and multiplicity of affirmative actions in higher education as they are assembled by social justice and exclusionary logics and participate in broader discursive struggles, ideologies, and contradictory state projects.Consejo Nacional de Innovación, Ciencia y Tecnologıa (Chile

Generalized iterated wreath products of cyclic groups and rooted trees correspondence

Consider the generalized iterated wreath product $\mathbb{Z}_{r_1}\wr \mathbb{Z}_{r_2}\wr \ldots \wr \mathbb{Z}_{r_k}$ where $r_i \in \mathbb{N}$. We prove that the irreducible representations for this class of groups are indexed by a certain type of rooted trees. This provides a Bratteli diagram for the generalized iterated wreath product, a simple recursion formula for the number of irreducible representations, and a strategy to calculate the dimension of each irreducible representation. We calculate explicitly fast Fourier transforms (FFT) for this class of groups, giving literature's fastest FFT upper bound estimate.Comment: 15 pages, to appear in Advances in the Mathematical Science

Total DNA Content and Ploidy Levels in Linnaeoideae with a Focus on Abelia

The Linnaeoideae subfamily was created in Caprifoliaceae to represent the close relationship among the monophyletic genera Abelia, Diabelia, Dipelta, Kolkwitzia, Linnaea, and Vesalea. These closely related genera could possibly be a new source of ornamental traits for Abelia, an economically important genus of woody ornamental shrubs. Breeding among these genera could be challenging as only a few genera and species have a reported total DNA content, ploidy level, and chromosome number. The objective of this research was to fill that gap in the literature. We determined the total DNA content and DNA ploidy levels and estimated chromosome numbers of the species Abelia chinensis (two genotypes), Abelia macrotera var. engleriana, Abelia ×grandiflora, Abelia schumanii, Diabelia serrata, Vesalea floribunda, Zabelia tyaihyonii var. mosanensis, and the Abelia cultivars Edward Goucher, Francis Mason, Lavender Mist, Raspberry Profusion, and Rosy Charm® by flow cytometry. Raphanus sativus ‘Saxa’ was used as an internal standard for holoploid 2C total genome size estimation. For DNA ploidy and chromosome number, A. ×grandiflora (2n = 2x = 32) and Z. tyaihyonii var. mosanensis (2n = 36) were used as internal standards. We also measured the pollen size and stomata length of the species A. chinensis (two genotypes), A. macrotera var. engleriana, V. floribunda, A. ×grandiflora, A. schumanii, and D. serrata, and the Abelia cultivars Francis Mason and Raspberry Profusion. All genotypes have a 2C holoploid total DNA content between 0.87 and 0.95 pg DNA (∼850–930 Mb), except for V. floribunda and Z. tyaihyonii var. mosanensis, which have 1.94 and 1.91 pg DNA, respectively (∼1880 Mb). All genotypes are diploid with 2n = 2x = 32, except for V. floribunda and Z. tyaihyonii var. mosanensis, which have 36 chromosomes (2n = ?x = 36). We observed significant variability in stomata sizes and pollen diameter independent of and not correlated with genome size or chromosome number. A. ×grandiflora has a high percentage of dead pollen (∼30%), as does V. floribunda (43%). This high percentage of dead pollen in the natural species V. floribunda could be the result of aneuploidy. This is the first report of total DNA content in A. chinensis, D. serrata, and Z. tyaihyonii var. mosanensis; total DNA content and estimated chromosome number in V. floribunda; total DNA content and DNA ploidy levels in A. ×grandiflora, A. macrotera var. engleriana, and A. schumanii; and total DNA content, estimated chromosome number, and DNA ploidy levels in the Abelia cultivars Edward Goucher, Francis Mason, Lavender Mist, Raspberry Profusion, and Rosy Charm®

Enhancing methane production from the invasive macroalga Rugulopteryx okamurae through anaerobic co-digestion with olive mill solid waste: process performance and kinetic analysis

The biomass valorisation of the invasive brown alga Rugulopteryx okamurae (Dictyotales, Phaeophyceae) is key to curbing the expansion of this invasive macroalga which is generating tonnes of biomass on southern Spain beaches. As a feasible alternative for the biomass management, anaerobic co-digestion is proposed in this study. Although the anaerobic digestion of macroalgae barely produced 177 mL of CH4 g−1 VS, the co-digestion with a C-rich substrate, such as the olive mill solid waste (OMSW, the main waste derived from the two-phase olive oil manufacturing process), improved the anaerobic digestion process. The mixture improved not only the methane yield, but also its biodegradability. The highest biodegradability was found in the mixture 1 R. okamurae—1 OMSW, which improved the biodegradability of the macroalgae by 12.9% and 38.1% for the OMSW. The highest methane yield was observed for the mixture 1 R. okamurae—3 OMSW, improving the methane production of macroalgae alone by 157% and the OMSW methane production by 8.6%. Two mathematical models were used to fit the experimental data of methane production time with the aim of assessing the processes and obtaining the kinetic constants of the anaerobic co-digestion of different combination of R. okamurae and OMSW and both substrates independently. First-order kinetic and the transference function models allowed for appropriately fitting the experimental results of methane production with digestion time. The specific rate constant, k (first-order model) for the mixture 1 R. okamurae- 1.5 OMSW, was 5.1 and 1.3 times higher than that obtained for the mono-digestion of single OMSW and the macroalga, respectively. In the same way, the transference function model revealed that the maximum methane production rate (Rmax) was also found for the mixture 1 R. okamurae—1.5 OMSW (30.4 mL CH4 g−1 VS day−1), which was 1.6 and 2.2 times higher than the corresponding to the mono-digestions of the single OMSW and sole R. okamurae (18.9 and 13.6 mL CH4 g−1 VS day−1), respectively.Ministerio de Ciencia e Innovación PID2020-114975RB-10

The Caveolin-1 Connection to Cell Death and Survival

Nunez, S (Nunez, S.)[ 1,4 ] 1. Fac Med, CEMC, Lab Comunicac Celulares, Santiago, Chile. 4. Univ Talca, Fac Hlth Sci, Talca, ChileCaveolins are a family of membrane proteins required for the formation of small plasma membrane invaginations called caveolae that are implicated in cellular trafficking processes. In addition to this structural role, these scaffolding proteins modulate numerous intracellular signaling pathways; often via direct interaction with specific binding partners. Caveolin-1 is particularly well-studied in this respect and has been attributed a large variety of functions. Thus, Caveolin-1 also represents the best-characterized isoform of this family with respect to its participation in cancer. Rather strikingly, available evidence indicates that Caveolin-1 belongs to a select group of proteins that function, depending on the cellular settings, both as tumor suppressor and promoter of cellular traits commonly associated with enhanced malignant behavior, such as metastasis and multi-drug resistance. The mechanisms underlying such ambiguity in Caveolin-1 function constitute an area of great interest. Here, we will focus on discussing how Caveolin-1 modulates cell death and survival pathways and how this may contribute to a better understanding of the ambiguous role this protein plays in cancer