The effect of electronic energy loss on the dynamics of thermal spikes in Cu

We present results of a molecular dynamics simulation study of the effect of electron-ion interactions on the dynamics of the thermal spike in Cu. Interatomic forces are described with a modified embedded atom method potential. We show that the electron-ion interaction acts to reduce the lifetime of the thermal spike and therefore the amount of atomic rearrangement that takes place in energetic displacement cascades in Cu. The results point toward the important effect that inelastic energy losses might have on the dynamics of displacement cascades in the subcascade energy regime where the lifetime of the thermal spike is expected to exceed the electron-phonon coupling tim

INCLUDING INDIGENOUS AND LOCAL KNOWLEDGE IN THE WORK OF THE INTERGOVERNMENTAL SCIENCE-POLICY PLATFORM ON BIODIVERSITY AND ECOSYSTEM SERVICES (IPBES) GLOBAL ASSESSMENT : Outcomes and lessons for the future

This chapter makes a strong case for greater inclusion of Indigenous and Local Knowledge (ILK) in global environmental policy fora and in science-policy interfaces. The chapter specifically looks at the IPBES Global Assessment which has developed one of the first global-scale mechanisms for operationalizing ILK in sustainability decision-making. The types of knowledges that have been successfully integrated into this assessment include ways in which ILK can help (1) to assess ecosystem change and associated human vulnerability; (2) to inform the achievement of global goals like the Sustainable Development Goals and Aichi Targets; and (3) to inform policy-relevant options for decision-makers. It is argued that other global initiatives seeking to engage ILK in their endeavours can learn from the ILK approach of the IPBES Global Assessment.Peer reviewe

Constraints on the parameters of the Left Right Mirror Model

We study some phenomenological constraints on the parameters of a left right model with mirror fermions (LRMM) that solves the strong CP problem. In particular, we evaluate the contribution of mirror neutrinos to the invisible Z decay width (\Gamma_Z^{inv}), and we find that the present experimental value on \Gamma_Z^{inv}, can be used to place an upper bound on the Z-Z' mixing angle that is consistent with limits obtained previously from other low-energy observables. In this model the charged fermions that correspond to the standard model (SM) mix with its mirror counterparts. This mixing, simultaneously with the Z-Z' one, leads to modifications of the \Gamma(Z --> f \bar{f}) decay width. By comparing with LEP data, we obtain bounds on the standard-mirror lepton mixing angles. We also find that the bottom quark mixing parameters can be chosen to fit the experimental values of R_b, and the resulting values for the Z-Z' mixing angle do not agree with previous bounds. However, this disagreement disappears if one takes the more recent ALEPH data.Comment: 7 pages, 2 figures, REVTe

Feminist Pedagogy in the STEM Research Laboratory: an Intersectional Approach

The research laboratory is a crucial and indispensable classroom for STEM education. It is where we practice science as a craft and test the ideas that awaken our curiosity, allowing us to create knowledge. It is also a space where challenges await and struggles are imminent. Thus, supporting mentees through their traineeship in a research lab requires an intersectional approach and lens to provide equitable mentorship and guidance. The concept of intersectionality, initially devised by Black feminist professor Kimberlé W. Crenshaw, can be employed to generate practices and frameworks that democratize laboratory culture and provide trainees with a space in which they shape the laboratory culture while helping them recognize their positionality. This critical commentary provides insights and experiences when incorporating feminist frameworks to sustain equitable working environments in the research lab setting, specifically in leading a research group composed predominantly of Puerto Rican women

Additive manufacturing of Al2O3 with engineered interlayers and high toughness through multi-material co-extrusion

The additive manufacturing of ceramic composites with tailored microstructures is still challenging and time-consuming. However, there is great interest as it may enable the implementation of novel materials architectures following computer designs. In this work, we demonstrate a straightforward method to obtain ceramics with a network of continuous weak interlayers designed to increase fracture resistance using alumina as a model system. This is achieved by combining direct ink writing with the coextrusion of multi-material pastes with carefully matched rheology based on thermally reversible hydrogels and inorganic powders. The printed Al2O3 bars with and without weak interlayers exhibit strengths ranging between 180 and 360 MPa and KIC ∼ 3 MPa∙m1/2. The introduction of weak interlayers using different raster patterns, such as length wise and Bouligand alignments can be used to direct crack propagation and promote gradual failure. The result is an improvement in the fracture energy up to 230 J/m2 and Kj up to 9 MPa·m1/2. These results suggest the potential of manufacturing ceramics with enhanced mechanical properties by using robocasting with multi-material inks to engineer complex interlayer networks

Acyl-CoA Synthetase 6 is Required for Brain Docosahexaenoic Acid Retention and Neuroprotection During Aging

The omega-3 fatty acid docosahexaenoic acid (DHA) inversely relates to neurological impairments with aging; however, limited nondietary models manipulating brain DHA have hindered a direct linkage. We discovered that loss of long-chain acyl-CoA synthetase 6 in mice (Acsl6(–/–)) depletes brain membrane phospholipid DHA levels, independent of diet. Here, Acsl6(–/–) brains contained lower DHA compared with controls across the life span. The loss of DHA- and increased arachidonate-enriched phospholipids were visualized by MALDI imaging predominantly in neuron-rich regions where single-molecule RNA in situ hybridization localized Acsl6 to neurons. ACSL6 is also astrocytic; however, we found that astrocyte-specific ACSL6 depletion did not alter membrane DHA because astrocytes express a non–DHA-preferring ACSL6 variant. Across the life span, Acsl6(–/–) mice exhibited hyperlocomotion, impairments in working spatial memory, and increased cholesterol biosynthesis genes. Aging caused Acsl6(–/–) brains to decrease the expression of membrane, bioenergetic, ribosomal, and synaptic genes and increase the expression of immune response genes. With age, the Acsl6(–/–) cerebellum became inflamed and gliotic. Together, our findings suggest that ACSL6 promotes membrane DHA enrichment in neurons, but not in astrocytes, and is important for neuronal DHA levels across the life span. The loss of ACSL6 impacts motor function, memory, and age-related neuroinflammation, reflecting the importance of neuronal ACSL6-mediated lipid metabolism across the life span

Genomic profiling of uterine aspirates and cfDNA as an integrative liquid biopsy strategy in endometrial cancer

The incidence and mortality of endometrial cancer (EC) have risen in recent years, hence more precise management is needed. Therefore, wecombined di erent types of liquid biopsies to better characterize the genetic landscape of EC in a non-invasive and dynamic manner. Uterine aspirates (UAs) from 60 patients with EC were obtained during surgery and analyzed by next-generation sequencing (NGS). Blood samples, collected at surgery, were used for cell-free DNA (cfDNA) and circulating tumor cell (CTC) analyses. Finally, personalized therapies were tested in patient-derived xenografts (PDXs) generated from the UAs. NGS analyses revealed the presence of genetic alterations in 93% of the tumors. Circulating tumor DNA (ctDNA) was present in 41.2% of cases, mainly in patients with high-risk tumors, thus indicating a clear association with a more aggressive disease. Accordingly, the results obtained during the post-surgery follow-up indicated the presence of ctDNA in three patients with progressive disease. Moreover, 38.9% of patients were positive for CTCs at surgery. Finally, the e cacy of targeted therapies based on the UA-specific mutational landscape was demonstrated in PDX models. Our study indicates the potential clinical applicability of a personalized strategy based on a combination of different liquid biopsies to characterize and monitor tumor evolution, and to identify targeted therapiesThis work was supported by grants and support from the Instituto de Salud Carlos III (ISCIII) and FEDER (PI17/01919, PI17/02071), CIBERONC (CB16/12/00328), and the AECC (Grupos Estables de Investigacion 2018-AECC) to A.G.-M. and M.A.; Instituto de Salud Carlos III (ISCIII) and FEDER (PI16/00134), CIBERONC (CB16/12/00295), and the AECC (Grupos Estables de Investigacion 2018-AECC) to G.M.-B.; and the AECC to L.M.-R

RNA extraction from self-assembling peptide hydrogels to allow qPCR analysis of encapsulated cells

Self-assembling peptide hydrogels offer a novel 3-dimensional platform for many applications in cell culture and tissue engineering but are not compatible with current methods of RNA isolation; owing to interactions between RNA and the biomaterial. This study investigates the use of two techniques based on two different basic extraction principles: solution-based extraction and direct solid-state binding of RNA respectively, to extract RNA from cells encapsulated in four β-sheet forming self-assembling peptide hydrogels with varying net positive charge. RNA-peptide fibril interactions, rather than RNA-peptide molecular complexing, were found to interfere with the extraction process resulting in low yields. A column-based approach relying on RNA-specific binding was shown to be more suited to extracting RNA with higher purity from these peptide hydrogels owing to its reliance on strong specific RNA binding interactions which compete directly with RNA-peptide fibril interactions. In order to reduce the amount of fibrils present and improve RNA yields a broad spectrum enzyme solution—pronase—was used to partially digest the hydrogels before RNA extraction. This pre-treatment was shown to significantly increase the yield of RNA extracted, allowing downstream RT-qPCR to be performed