112 research outputs found
A New Tribe of Saber-toothed Cats (\u3ci\u3eBarbourofelini\u3c/i\u3e) from the Pliocene of North America
A new genus of Pliocene Saber-toothed felid, Barbourofelis, is proposed and two new species B. fricki and B. morrisi are described. These two forms and other described material represent an unusual lineage of felids with long sabers, shortened crania, and massive postorbital bars. The tribal name Barbourofelini is proposed for this lineage which is presently known in North America from deposits ranging in age from Clarendonian through Kimballian. The Barbourofelini apparently migrated from Eurasia to North America in the Late Miocene or Early Pliocene. Sansanosmilus of the French Vindobonian appears to represent the ancestral stock of these cats. The following genera of other saber-toothed felids are discussed: Hoplophoneus, Eusmilus, Dinictis, Nimravus, Ekgmoiteptecela, Ma.chairodus, Ischyrosmilus, Homotherium, H. (Dinobastis), Megantereon, and Smilodon. The two generic names Albanosmilus and Grivasmilus also are considered. The continued usage of the provincial age terms Valentinian and Kimballian is recommended, and a faunal list for these units in Nebraska is provided
The âEagleâ Approach To Train Electrical Engineers With Collaborative Problem-Solving Skills
Extracting the spectral signature of alpha-clustering in 44,48,52Ti using the continuous wavelet transform
A novel technique has been developed, making use of the continuous wavelet transform to identify
α-clustered states from resonant scattering measurements in regions of high nuclear state density.
This technique expedites the investigation of α-clustering in medium mass and heavy nuclei, where
the role that α-clustering plays in the structure of the nucleus is poorly understood. Here we report
the application of this technique to measurements of the 4He(40,44,48Ca,α) resonant reactions, leading
to an assessment of the α-cluster structure of 44,48,52Ti. Alpha-clustering was identified in 44Ti and
52Ti, but was observed to break down in 48Ti. The implications of these results are discussed
Genetic characterization of populations in the Marquesas Archipelago in the context of the Austronesian expansion
Our exploration of the genetic constitution of Nuku Hiva (n = 51), Hiva Oa (n = 28) and Tahuata (n = 8) of the Marquesas Archipelago based on the analyses of genome-wide autosomal markers as well as high-resolution genotyping of paternal and maternal lineages provides us with information on the origins and settlement of these islands at the fringe of the Austronesian expansion. One widespread theme that emerges from this study is the genetic uniformity and relative isolation exhibited by the Marquesas and Society populations. This genetic homogeneity within East Polynesia groups is reflected in their limited average heterozygosity, uniformity of constituents in the Structure analyses, reiteration of complete mtDNA sequences, marked separation from Asian and other Oceanic populations in the PC analyses, limited differentiation in the PCAs and large number of IBD segments in common. Both the f3 and the Outgroup f3 results provide indications of intra-East Polynesian gene flow that may have promoted the observed intra-East Polynesia genetic homogeneity while ALDER analyses indicate that East Polynesia experienced two gene flow episodes, one relatively recent from Europe that coincides roughly with the European incursion into the region and an early one that may represent the original settlement of the islands by Austronesians. Median Network analysis based on high-resolution Y-STR loci under C2a-M208 generates a star-like topology with East Polynesian groups (especially from the Society Archipelago) in central stem positions and individuals from the different populations radiating out one mutational step away while several Samoan and outlier individuals occupy peripheral positions. This arrangement of populations is congruent with dispersals of C2a-M208 Y chromosomes from East Polynesia as a migration hub signaling dispersals in various directions. The equivalent ages of the C2a-M208 lineage of the populations in the Network corroborate an east to west flow of the most abundant Polynesian Y chromosome
The identification of α -clustered doorway states in 44, 48, 52 Ti using machine learning
Abstract: A novel experimental analysis method has been developed, making use of the continuous wavelet transform and machine learning to rapidly identify α-clustering in nuclei in regions of high nuclear state density. This technique was applied to resonant scattering measurements of the 4He(40,44,48Ca,α) resonant reactions, allowing the α-cluster structure of 44,48,52Ti to be investigated. Fragmented α-clustering was identified in 44Ti and 52Ti, while the results for 48Ti were less conclusive, but suggest no such clustering
High doses of medroxyprogesterone as the cause of disappearance of adherence of the zona pellucida to an oocyte
The zona pellucida (ZP) is an external glycoprotein membrane of oocytes of mammals and embryos in the early stage of their development. ZP first appears in growing ovarian follicles as an extracellular substance between the oocyte and granular cells. The zona pellucid markedly affects the development and maturation of the oocyte. The morphology of the ZP-oocyte complex allows a more precise determination of the oocyte maturity. According to numerous experimental studies, ZP is essential for preimplantation embryonic development of humans and other mammals. It prevents dispersion of blastomeres and enhances their mutual interactions. ZP is a dynamic structure responsible for the provision of nutrients to early forms of oocytes in mammals. The aim of the present study was untrastructural evaluation of the ZP-oocyte contact during inhibited ovulation. Female white rats (Wistar strain) received a suspension of medroxyprogesterone acetate (MPA) in incremental intramuscular bolus doses of 3.7Â mg (therapeutic dose), 7.4Â mg and 11.1Â mg. The animals were decapitated 5Â days after the administration of MPA. Ovarian sections were evaluated under a transmission electron microscope (TEM) Zeiss EM 900. Morphometric analysis of ZP was conducted using the cell imaging system by Olympus. In females exposed to therapeutic doses of MPA, ZP showed the structure of granular-fibrous reticulum of a medium electron density with single cytoplasmic processes originating from the surrounding structures. The oocyte cell membrane generated single, delicate processes directed toward ZP. Microvilli of the oocyte were short and thin. In the group receiving 7.4Â mg of MPA, ZP had the structure of a delicate, loose granular-fibrous reticulum, and the oocyte cell membrane generated single microvilli directed toward ZP. In both those groups, the close ZP-oocyte contact was observed. Otherwise, in the group exposed to the highest MPA doses (11.1Â mg), thicker and more numerous oocyte microvilli were found, which did not penetrate ZP matrix. They were dense, irregularly separated contour, forming a barrier between ZP and oocyte. The present findings are likely to suggest that MPA has inhibiting effects on the synthesis of binding proteins and causes the loss of the oocyte contact with ZP
KEAP1-modifying small molecule reveals muted NRF2 signaling responses in neural stem cells from Huntington's disease patients
The activity of the transcription factor nuclear factor-erythroid 2 p45-derived factor 2 (NRF2) is orchestrated and amplified through enhanced transcription of antioxidant and antiinflammatory target genes. The present study has characterized a triazole-containing inducer of NRF2 and elucidated the mechanism by which this molecule activates NRF2 signaling. In a highly selective manner, the compound covalently modifies a critical stress-sensor cysteine (C151) of the E3 ligase substrate adaptor protein Kelch-like ECH-associated protein 1 (KEAP1), the primary negative regulator of NRF2. We further used this inducer to probe the functional consequences of selective activation of NRF2 signaling in Huntington's disease (HD) mouse and human model systems. Surprisingly, we discovered a muted NRF2 activation response in human HD neural stem cells, which was restored by genetic correction of the disease-causing mutation. In contrast, selective activation of NRF2 signaling potently repressed the release of the proinflammatory cytokine IL-6 in primary mouse HD and WT microglia and astrocytes. Moreover, in primary monocytes from HD patients and healthy subjects, NRF2 induction repressed expression of the proinflammatory cytokines IL-1, IL-6, IL-8, and TNFα. Together, our results demonstrate a multifaceted protective potential of NRF2 signaling in key cell types relevant to HD pathology
Towards a European Health Research and Innovation Cloud (HRIC)
The European Union (EU) initiative on the Digital Transformation of Health and Care (Digicare) aims to provide the conditions necessary for building a secure, flexible, and decentralized digital health infrastructure. Creating a European Health Research and Innovation Cloud (HRIC) within this environment should enable data sharing and analysis for health research across the EU, in compliance with data protection legislation while preserving the full trust of the participants. Such a HRIC should learn from and build on existing data infrastructures, integrate best practices, and focus on the concrete needs of the community in terms of technologies, governance, management, regulation, and ethics requirements. Here, we describe the vision and expected benefits of digital data sharing in health research activities and present a roadmap that fosters the opportunities while answering the challenges of implementing a HRIC. For this, we put forward five specific recommendations and action points to ensure that a European HRIC: i) is built on established standards and guidelines, providing cloud technologies through an open and decentralized infrastructure; ii) is developed and certified to the highest standards of interoperability and data security that can be trusted by all stakeholders; iii) is supported by a robust ethical and legal framework that is compliant with the EU General Data Protection Regulation (GDPR); iv) establishes a proper environment for the training of new generations of data and medical scientists; and v) stimulates research and innovation in transnational collaborations through public and private initiatives and partnerships funded by the EU through Horizon 2020 and Horizon Europe
Alpha clustering in Ti isotopes: 40, 44, 48Ca+ α resonant scattering
Measurements were made of the 4He(40,44,48Ca,α) resonant scattering reactions at 180° and up to Ec.m. ~ 11.5MeV, using the Thick Target Inverse Kinematics technique. These measurements are discussed, with a focus on assessing their usefulness for investigating α-clustering in medium mass 44,48,52Ti nuclei
Complex speech-language therapy interventions for stroke-related aphasia:The RELEASE study incorporating a systematic review and individual participant data network meta-analysis
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