Experimental insights into electrocatalytic [Cp*Rh(bpy)Cl]+ mediated NADH regeneration.

NADH plays a crucial role in many enzymatically catalysed reactions. Due to the high costs of NADH a regeneration mechanism of this cofactor can enlarge the applications of enzymatic reactions dramatically. This paper gives a thorough system analysis of the mediated electrochemical regeneration of active NADH using cyclic voltammograms and potentiostatic measurements with varying pH, electrode potential, and electrolyte solution, highlighting the system's limiting conditions, elucidating optimal working parameters for the electrochemical reduction of NAD+, and bringing new insight on the oxidation of inactive reduction products. Using [Cp*Rh(bpy)Cl]+ as an electron mediator dramatically increases the percentage of enzymatically active electrochemically reduced NADH from 15% (direct) to 99% (mediated) with a faradaic efficiency of up to 86%. Furthermore, investigations of the catalytic mechanisms of [Cp*Rh(bpy)Cl]+ clarifies the necessary conditions for its functioning and questions the proposed reaction mechanism by two-step reduction where first the mediator is reduced and then brought in contact with NAD+.

Influence of electrode potential, pH and NAD+ concentration on the electrochemical NADH regeneration.

Electrochemical NAD+ reduction is a promising method to regenerate NADH for enzymatic reactions. Many different electrocatalysts have been tested in the search for high yields of the 1,4-isomer of NADH, the active NADH, but aside from electrode material, other system parameters such as pH, electrode potential and educt concentration also play a role in NADH regeneration. The effect of these last three parameters and the mechanisms behind their influence on NADH regeneration was systematically studied and presented in this paper. With percentages of active NADH ranging from 10 to 70% and faradaic efficiencies between 1 and 30%, it is clear that all three system parameters drastically affect the reaction outcome. As a proof of principle, the NAD+ reduction in the presence of pyruvate and lactate dehydrogenase was performed. It could be shown that the electrochemical NADH regeneration can also be done successfully in parallel to enzymatically usage of the regenerated cofactor.

The D165H Polymorphism of QiMYB-like-1 Is Linked to Interactions between Tannin Accumulation, Herbivory and Biogeographical Determinants of Quercus ilex.

The accumulation in the leaves and young stems of phenolic compounds, such as hydrolyzable and condensed tannins, constitutes a defense mechanism of plants against herbivores. Among other stressing factors, chronic herbivory endangers Quercus ilex, a tree playing a central role in Mediterranean forests. This work addressed the connections between the chemical defenses of Q. ilex leaves and their susceptibility to herbivory, quantitative traits whose relationships are modulated by environmental and genetic factors that could be useful as molecular markers for the selection of plants with improved fitness. A search for natural variants detected the polymorphism D165H in the effector domain of QiMYB-like-1, a TT2-like transcription factor whose family includes members that control the late steps of condensed tannins biosynthesis in different plant species. QiMYB-like-1 D165H polymorphism was screened by PCR-RFLP in trees from six national parks in Spain where Q. ilex has a relevant presence, revealing that, unlike most regions that match the Hardy-Weinberg equilibrium, homozygous plants are over-represented in "Monfragüe" and "Cabañeros", among the best examples to represent the continental Mediterranean (cM) ecosystem. Accordingly, the averages of two stress-related quantitative traits measured in leaves, herbivory index and accumulation of condensed tannins, showed asymmetric distributions depending on the clustering of trees based on ecological and genetic factors. Thus, the impact of herbivory was greater in managed forests with a low density of trees from the cM region, among which QiMYB-like-1 D165 homozygotes stand out, whereas condensed tannins accumulation was higher in leaves of QiMYB-like-1 H165 homozygotes from low-density forests, mainly in the Pyrenean (Py) region. Besides, the correlation between the contents of condensed tannins and total tannins vanished after clustering by the same factors: the cM region singularity, forest tree density, and QiMYB-like-1 genotype, among which homozygous shared the lowest link. The biogeographical and genetic constraints that modulate the contribution of condensed tannins to chemical defenses also mediated their interactions with the herbivory index, which was found positively correlated with total phenolics or tannins, suggesting an induction signal by this biotic stress. In contrast, a negative correlation was observed with condensed tannins after tree clustering by genetics factors where associations between tannins were lost. Therefore, condensed tannins might protect Q. ilex from defoliation in parks belonging to the cM ecosystem and carrying genetic factor(s) linked to the QiMYB-like-1 D165H polymorphism.

Improving Department Climate Through Bias Literacy: One College's Experience.

Many institutions of higher education are investing in "implicit bias training" as a mechanism to improve diversity and inclusion on their campuses. In this study, we describe an effort to implement this training in the form of a 3-hour workshop delivered to faculty members in the College of Engineering at the University of Wisconsin-Madison. Evaluation form data collected immediately post-workshop, and in-person interviews and survey data collected 6-12 months post-workshop, were used to measure the effectiveness of the intervention. These data show that faculty awareness of implicit bias in their workplace environments increased significantly, although individual motivation and self-efficacy to act without bias, and self-reported bias-reduction actions, did not increase. At the same time, we found evidence of improved department climates and bias-reduction actions at the department level, which increase our confidence that the workshops were having a positive impact. Importantly, women and faculty of color in the College did not report increases in negative behavior after the workshop, and reported that their departments were engaging in explicit discussions of potential biases in departmental processes more often. These findings support the continued implementation of the "Breaking the Bias Habit®" workshops along with measurement of their success.

The effects of atrazine on the microbiome of the eastern oyster: Crassostrea virginica.

Long-standing evidence supports the importance of maintaining healthy populations of microbiota for the survival, homeostasis, and complete development of marine mollusks. However, the long-term ecological effects of agricultural runoff on these populations remains largely unknown. Atrazine (6-Chloro-n-ethyl-n'-(1-methylethyl)-triazine-2,4-diamine), a prevalent herbicide in the United States, is often used along tributaries of the Chesapeake Bay where oyster breeding programs are concentrated. To investigate any potential effects atrazine maybe having on mollusk-prokaryote interactions, we used 16S rRNA gene amplicons to evaluate how microbial compositions shift in response to exposure of environmentally relevant concentrations of atrazine previously found within the Chesapeake Bay. The dominant bacterial genera found within all groups included those belonging to Pseudoalteromonas, Burkholderia, Bacteroides, Lactobacillis, Acetobacter, Allobaculum, Ruminococcus, and Nocardia. Our results support previously published findings of a possible core microbial community in Crassostrea virginica. We also report a novel finding: oysters exposed to atrazine concentrations as low as 3 µg/L saw a significant loss of a key mutualistic microbial species and a subsequent colonization of a pathogenic bacteria Nocardia. We conclude that exposure to atrazine in the Chesapeake Bay may be contributing to a significant shift in the microbiomes of juvenile oysters that reduces fitness and impedes natural and artificial repopulation of the oyster species within the Bay.

Pesquisando cidade e subjetividade: corpos e errâncias de um flâneur-cartógrafo / Researching city and subjectivity: bodies and wanderings of a flâneur-cartographer / Investigando ciudad y subjetividad: cuerpos y errancias de un flâneur-cartógrafo

À luz do método de pesquisa-intervenção da cartografia, proposto por Gilles Deleuze e Félix Guattari (2011), apresentamos reflexões sobre o estudo da subjetividade e da cidade contemporânea em suas dimensões processuais e produtivas. O corpo do cartógrafo emerge como central para a metodologia, sendo criado ao longo do processo de pesquisa a fim de existencializar universos de referência (Rolnik, 1993) de modos de existência na urbe. Desenvolvemos, então, relações entre a prática do cartógrafo e a do flâneur enquanto exemplos de errâncias urbanas (Jacques, 2012) que problematizam as possibilidades da experiência corporal no espaço urbano como resistência à espetacularização das cidades contemporâneas. Para tal, utilizamos conceitos-ferramentas do campo da esquizoanálise e dos autores citados neste resumo, desenvolvendo a ideia de que experiências urbanas, sob certos modos, podem se revelar como fonte de produção e de conhecimento sobre a subjetividade, a cidade, o corpo assim como sobre as relações entre eles.

In light of the cartographic method of research proposed by Gilles Deleuze and Félix Guattari (2011), we present reflections on the study on subjectivity and the contemporary city with an approach to its process and production dimensions. The cartographer's body is crucial for the methodology and is created along the research process in order to allow for the existence of universes of reference (Rolnik, 1993) of modes of existence in urban life. We then develop relationships between the cartographer's practice and that of the flâneur as examples of urban wandering (Jacques, 2012) that problematize the possibilities of body experiences in the urban space as a resistance to the contemporary spectacularization of the city. For such, we use concepts-tools from the field of schizoanalysis and those of the authors mentioned in this abstract,developing the idea that urban experiences, in some ways, can prove to be a source of production and knowledge of subjectivity, the city, the body and the relationships between them.

Basándonos en el método de investigación-intervención de la cartografía, propuesta por Gilles Deleuze y Félix Guattari (2011), presentamos a continuación reflexiones sobre el estudio de la subjetividad y de la ciudad contemporánea, en sus dimensiones procesuales y productivas. El cuerpo del cartógrafo emerge como central para la metodología, creándose a lo largo del proceso de investigación, con el fin de dar forma a universos de referencia (Rolnik, 1993) de modos de existencia en la urbe. Desarrollamos, pues, relaciones entre la práctica del cartógrafo y la del flâneur, como ejemplos de tipos errantes urbanos (Jacques, 2012) que problematizan las posibilidades de la experiencia corporal en el espacio urbano como resistencia a la espectacularidad de las ciudades contemporáneas. Para ello, utilizamos conceptos-herramientas del campo del esquizoanálisis y de los autores citados en este resumen, para desarrollar la idea de que las experiencias urbanas, en algunos modos, pueden revelarse como fuentes de producción y de conocimiento sobre la subjetividad, la ciudad, el cuerpo y las relaciones entre ellos.