The paradoxes of applying ethnography at a distance: Dürer’s Rhinoceros

In 1515, Albrecht Dürer received news of an animal encased in armour: it was an Indian rhinoceros which was being transported towards Rome as a present for Pope Leo X. The description and a sketch of the animal, arrived in Dürer’s hands, he made a woodcut that Europeans came to adopt as the true depiction of the rhinoceros. Dürer would never see an actual rhinoceros in his life. Nevertheless, this legendary woodcut creature shaped the public perception of a rhinoceros for the next two centuries. Is it art’s idealisation of the natural world the answer to overcoming distance? Or are metaphors just another type of truth? Prevented by the Covid-19 circumstances from going out to the field, Dürer’s Rhinoceros has become more than a metaphor for my project. My research included the production of a documentary in-situ, which soon changed for the production of a documentary at a distance. The different narratives created by the socio-cultural context and the documentary filmmaker’s commitment to truth hang over her like a sword of Damocles. I attempted to find solutions and other ways to reproduce the same proximity at a distance resourcing to online/research. In a moment of enthusiasm, and encouraged by early investigations, I wrote: ‘To recreate the proximity that this research needs, it is necessary to devise a new methodology, incorporating a strong network of collaborators, between researchers in the field, leaders of organisations and individuals prepared to communicate at a distance in a collective and polyphonic way’. This paper will analyse the different methods of conducting an online research in times of pandemic and crisis, to determine how narratives are created. As with Dürer’s woodcut, Rhinoceros, reality is very different

Maya women contest online narratives in action: creating equality through horizontal communication

Feminist Maya women have been contesting the narrative imposed by the state, social prejudices and media-imposed perceptions in contemporary Guatemala, reclaiming their place in society. This has been documented from an indigenous perspective (Chirix, 2008; Hernández-Castillo, 2010; Tzul Tzul, 2018; Cumes, 2019). In the long thread of history the indigenous population of Guatemala has resisted colonial imposition through the use of multiple strategies of adaptation, sometimes utilising elements of the dominant culture. In this case the creation of an online/virtual place in social media to defend and fight for their rights during the Covid-19 pandemic. By studying the case of the Guatemalan National Midwives Movement from a decolonial perspective and analysing the online development of: horizontal communication theory (Beltrán, 1979), in exceptional pandemic circumstances, will allow us to uncover: how indigenous women define their identity in relation to their knowledge, world-views and philosophies in their own voices, beyond any type of discrimination social or economic. This will enable a better understanding of how their communal organisational and communication strategies differ from Western individualism. However, social media cannot be fully representative of the indigenous midwives’ culture. The process of conveying meanings by words in a language that it is not your own and in contested media, such as an online/virtual place, certainly implies a process of surrendering. As Rivera Cusicanqui (2020) argues ‘in colonialism there is a very particular function for words, they do not name, they mask.’ This paper concludes that feminist decolonisation, cannot solely be rhetoric, but needs to be put to practice in every action

The solution of the equation XA+AXT=0 and its application to the theory of orbits

Abstractdescribe how to find the general solution of the matrix equation XA+AXT=0, with A∈Cn×n, which allows us to determine the dimension of its solution space. This result has immediate applications in the theory of congruence orbits of matrices in Cn×n, because the set {XA+AXT:X∈Cn×n} is the tangent space at A to the congruence orbit of A. Hence, the codimension of this orbit is precisely the dimension of the solution space of XA+AXT=0. As a consequence, we also determine the generic canonical structure of matrices under the action of congruence. All these results can be directly extended to palindromic pencils A+λAT

A class of quasi-sparse companion pencils

In this paper, we introduce a general class of quasi-sparse potential companion pencils for arbitrary square matrix polynomials over an arbitrary field, which extends the class introduced in [B. Eastman, I.-J. Kim, B. L. Shader, K.N. Vander Meulen, Companion matrix patterns. Linear Algebra Appl. 436 (2014) 255-272] for monic scalar polynomials. We provide a canonical form, up to permutation, for companion pencils in this class. We also relate these companion pencils with other relevant families of companion linearizations known so far. Finally, we determine the number of different sparse companion pencils in the class, up to permutation.This work has been partially supported by theMinisterio de Economía y Competitividad of Spain through grants MTM2015-68805-REDT and MTM2015-65798-P

The Polynomial Eigenvalue Problem is Well Conditioned for Random Inputs

We compute the exact expected value of the squared condition number for the polynomial eigenvalue problem, when the input matrices have entries coming from the standard complex Gaussian distribution, showing that in general this problem is quite well conditioned.The first author's work was partially supported by Agencia Nacional de Investigación e Innovación (ANII), Uruguay, and by CSIC group 618, Universidad de La República, Uruguay. The second author's work was partially supported by MTM2017-83816-P and MTM2017-90682-REDT from Spanish Ministry of Science MICINN and by 21.SI01.64658 from Universidad de Cantabria and Banco de Santander

Differential proteomic analysis of lactic acid bacteria - Escherichia coli O157:H7 interaction and its contribution to bioprotection strategies in meat

Original ResearchHuman infection by Enterohemorrhagic Escherichia (E.) coli (EHEC) occurs through the ingestion of contaminated foods such as milk, vegetable products, water-based drinks, and particularly minced meats. Indeed EHEC is a pathogen that threatens public health and meat industry. The potential of different Lactic Acid Bacteria (LAB) strains to control EHEC in a meat-based medium was evaluated by using a simple and rapid method and by analyzing the growth kinetics of co-cultures (LAB-EHEC) in a meat-based medium. The activity of LAB toward EHEC in co-cultures showed variable inhibitory effect. Although, LAB were able to control EHEC, neither the produced acid nor bacteriocins were responsible of the inhibition. The bacteriocinogenic Enteroccus (Ent.) mundtii CRL35 presented one of the highest inhibition activities. A proteomic approach was used to evaluate bacterial interaction and antagonistic mechanisms between Ent. mundtii and EHEC. Physiological observations, such as growth kinetics, acidification ability and EHEC inhibitory potential were supported by the proteomic results, demonstrating significant differences in protein expression in LAB: (i) due to the presence of the pathogen and (ii) according to the growth phase analyzed. Most of the identified proteins belonged to carbohydrate/amino acid metabolism, energy production, transcription/translation, and cell division. These results contribute to the knowledge of competition strategies used by Ent. mundtii during its co-culture with EHEC setting new perspectives for the use of LAB to control this pathogen in meatinfo:eu-repo/semantics/publishedVersio

Comparison of two sample preparation methods for 1H-NMR wine profiling: Direct analysis and solid-phase extraction

This study compares two sample preparation methods: direct analysis (DA) and solid-phase extraction (SPE) for wine samples analysis by proton nuclear magnetic resonance (1H-NMR) spectroscopy. For this purpose, the profile of Mexican commercial wines was evaluated. The selected wines were produced with different grape varieties: ('Barbera', 'Nebbiolo', 'Zinfandel', 'Merlot', 'Petite Syrah', 'Cabernet Sauvignon', 'White Zinfandel' and mixture of 'Chenin blanc' and 'Colombard') coming from the principal wine-producing region of Mexico, Baja California State. DA provided faster data acquisition in comparison to SPE and preserved the original sample composition. Using DA-NMR thirty two metabolites were identified, including organic acids, amino acids, sugars, alcohols and phenolic compounds. Furthermore, SPE-NMR using a polymeric sorbent allowed to retain phenolic compounds giving a better picture on the aromatic region and eliminating major polar compounds like water, ethanol and sugars. Fourteen compounds were identified by SPE-NMR including higher alcohols, flavanols and hydroxybenzoates. A control chart for the first principal component allowed to confirm the precision of the SPE-NMR method, while a comparison of the concentration of two metabolites found in both methods was used to evaluate their recovery (20 % for isoamyl alcohol and 78 % for phenethyl alcohol). The information obtained with both methods about the main compounds and phenolic metabolites provides new insights into the metabolomic profile of wine, which could be useful in future targeted studies