Hamster oocyte membrane potential and ion permeability vary with preantral cumulus cell attachment and developmental stage

BACKGROUND: In vitro maturation of mammalian oocytes is an area of great interest due to its potential application in the treatment of infertility. The morphological and physiological changes that occur during oocyte development are poorly understood, and further studies are needed investigating the physiological changes associated with oocyte maturation. In this study we evaluated the membrane potential and the sodium/potassium permeability ratio of oocytes acutely isolated, and cumulus-oocyte complexes in metaphase II and preantral follicle stages. RESULTS: Intracellular electrical recordings revealed that cumulus-enclosed oocytes have a membrane potential significantly more negative at the preantral follicle stage than at metaphase II stage (-38.4 versus -19.7 mV, p < 0.0005). The membrane potential of the cumulus-free oocytes was not different between the preantral and metaphase II stages. The membrane potential of the cumulus cells forming preantral stage follicles was shown to be significantly different from that of the oocyte within the follicle (-28.6 versus -38.4 mV, p < 0.05). The sodium/potassium permeability measured in cumulus-enclosed oocytes at the preantral stage equaled a mean value of 0.33. The ratio was significantly lower when measured in oocytes denuded of cumulus cells or cumulus-enclosed metaphase II oocytes, 0.76, 0.79, 0.77 respectively (p < 0.001). CONCLUSIONS: These data show a change in the membrane potential and Na(+)/K(+) permeability ratio during ooycte development from the preantral stage oocyte to the metaphase II stage. We have also demonstrated a change in the preantral oocyte membrane potential when surrounding cumulus cells are removed; either due to membrane changes or loss of cumulus cells

Compositional Constraints for Lucy Mission Trojan Asteroids via Near-Infrared Spectroscopy

We report near-infrared (0.7-2.5 micron) reflectance spectra for each of the six target asteroids of the forthcoming NASA Discovery-class mission Lucy. Five Jupiter Trojans (the binary (617) Patroclus system, (3548) Eurybates, (21900) Orus, (11351) Leucus, and (15094) Polymele) are well-characterized, with measurable spectral differences. We also report a survey-quality spectrum for main belt asteroid (52246) Donaldjohanson. We measured a continuum of spectral slopes including "red" (Orus, Leucus), "less red" (Eurybates, Patroclus-Menoetius) and intermediate (Polymele), indicating a range of compositional end-members or geological histories. We perform radiative transfer modeling of several possible surface compositions. We find that the mild-sloped spectra and low albedo of Patroclus and Eurybates imply similar compositions. Eurybates (~7 wt.% water ice) and Patroclus (~4 wt.% water ice) are consistent with a hydrated surface. Models for Orus and Leucus are consistent with each other and require a significantly more reddening agent (e.g. iron-rich silicates or tholin-like organics). Polymele has a linear spectrum like Patroclus, but a higher albedo more closely aligned with Orus/Leucus, defying simple grouping. Solar system formation models generally predict that the Jovian Trojans accreted in the outer solar system. Our observations and analysis are generally consistent with this expectation, although not uniquely so.Comment: Accepted by AJ. 10 Figures, 5 Table

Detection of neuron-derived cfDNA in blood plasma: a new diagnostic approach for neurodegenerative conditions

Neurodegenerative diseases, such as Alzheimer’s disease (AD), pose significant challenges in early diagnosis, leading to irreversible brain damage and cognitive decline. In this study, we present a novel diagnostic approach that utilizes whole molecule analysis of neuron-derived cell-free DNA (cfDNA) as a biomarker for early detection of neurodegenerative diseases. By analyzing Differential Methylation Regions (DMRs) between purified cortical neurons and blood plasma samples, we identified robust biomarkers that accurately distinguish between neuronal and non-neuronal cfDNA. The use of cfDNA offers the advantage of convenient and minimally invasive sample collection compared to traditional cerebrospinal fluid or tissue biopsies, making this approach more accessible and patient friendly. Targeted sequencing at the identified DMR locus demonstrated that a conservative cutoff of 5% of neuron-derived cfDNA in blood plasma accurately identifies 100% of patients diagnosed with AD, showing promising potential for early disease detection. Additionally, this method effectively differentiated between patients with mild cognitive impairment (MCI) who later progressed to AD and those who did not, highlighting its prognostic capabilities. Importantly, the differentiation between patients with neurodegenerative diseases and healthy controls demonstrated the specificity of our approach. Furthermore, this cfDNA-based diagnostic strategy outperforms recently developed protein-based assays, which often lack accuracy and convenience. While our current approach focused on a limited set of loci, future research should explore the development of a more comprehensive model incorporating multiple loci to increase diagnostic accuracy further. Although certain limitations, such as technical variance associated with PCR amplification and bisulfite conversion, need to be addressed, this study emphasizes the potential of cfDNA analysis as a valuable tool for pre-symptomatic detection and monitoring of neurodegenerative diseases. With further development and validation, this innovative diagnostic strategy has the potential to significantly impact the field of neurodegenerative disease research and patient care, offering a promising avenue for early intervention and personalized therapeutic approaches

Dynamical Evolution of Simulated Particles Ejected from Asteroid Bennu

In early 2019, the OSIRIS‐REx spacecraft discovered small particles being ejected from the surface of the near‐Earth asteroid Bennu. Although they were seen to be ejected at slow speeds, on the order of tens of cm/s, a number of particles were surprisingly seen to orbit for multiple revolutions and days, which requires a dynamical mechanism to quickly and substantially modify the orbit to prevent re‐impact upon their first periapse passage. This paper demonstrates that, based on simulations constrained by the conditions of the observed events, the combined effects of gravity, solar radiation pressure, and thermal radiation pressure from Bennu can produce many sustained orbits for ejected particles. Furthermore, the simulated populations exhibit two interesting phenomena that could play an important role in the geophysical evolution of bodies such as Bennu. First, small particles (<1 cm radius) are preferentially removed from the system, which could lead to a deficit of such particles on the surface. Second, re‐impacting particles preferentially land near or on the equatorial bulge of Bennu. Over time, this can lead to crater in‐filling and growth of the equatorial radius without requiring landslides

Widespread carbon-bearing materials on near-Earth asteroid (101955) Bennu

(101955) Bennu is a dark asteroid on an Earth-crossing orbit, thought to have assembled from the fragments of an ancient collision. We use spatially-resolved visible and near-infrared spectra of Bennu to investigate its surface properties and composition. In addition to a hydrated phyllosilicate band, we detect a ubiquitous 3.4-micron absorption feature, which we attribute to a mix of organic and carbonate materials. The shape and depth of this absorption feature vary across Bennu’s surface, spanning the range seen among similar main-belt asteroids. Its distribution does not correlate with temperature, reflectance, spectral slope, or hydrated minerals, although some of those characteristics correlate with each other. The deepest 3.4-micron absorptions occur on individual boulders. The variations may be due to differences in abundance, recent exposure, or space weathering

The Science Case for an Extended Spitzer Mission

Although the final observations of the Spitzer Warm Mission are currently scheduled for March 2019, it can continue operations through the end of the decade with no loss of photometric precision. As we will show, there is a strong science case for extending the current Warm Mission to December 2020. Spitzer has already made major impacts in the fields of exoplanets (including microlensing events), characterizing near Earth objects, enhancing our knowledge of nearby stars and brown dwarfs, understanding the properties and structure of our Milky Way galaxy, and deep wide-field extragalactic surveys to study galaxy birth and evolution. By extending Spitzer through 2020, it can continue to make ground-breaking discoveries in those fields, and provide crucial support to the NASA flagship missions JWST and WFIRST, as well as the upcoming TESS mission, and it will complement ground-based observations by LSST and the new large telescopes of the next decade. This scientific program addresses NASA's Science Mission Directive's objectives in astrophysics, which include discovering how the universe works, exploring how it began and evolved, and searching for life on planets around other stars.Comment: 75 pages. See page 3 for Table of Contents and page 4 for Executive Summar

Crop Updates 2000 Cereals - part 4

This session covers twelve papers from different authors: BREEDING 1.Response to subsoil acidity of wheat genotypes differing in Al-tolerance, C. Tang, Z. Rengel, E. Diatloff and B. McGann, Soil Science and Plant Nutrition/CLIMA, University of Western Australia 2. Application of molecular markers in Barley Improvement, Mehmet Cakir1, Nick Galwey1 and David Poulsen2, 1Plant Sciences, Faculty of Agriculture, University of Western Australia, 2Queensland Department of Primary Industries, Hermitage Research Station, Queensland 3. Implementation of molecular markers for wheat improvement in the Western Region, M. Carter1, A. Briney1, R. Wilson2, R.H. Potter1 and M.G.K. Jones1, 1Western Australian State Agricultural Biotechnology Centre, Murdoch University, 2Crop Industries, Agriculture Western Australia 4. Performance in 1999 of recently released wheat varieties in Western Australia, Robin Wilson, Iain Barclay, Robyn McLean, Dean Diepeveen and Robert Loughman, Agriculture Western Australia ECONOMICS 5. Outlook for prices and implications for rotations, Ross Kingwell1 2, Michael O’Connell1, Simone Blennerhasset1 1Agriculture Western Australia, 2University of Western Australia 6. Price Risk Management and the Western Australian Grain Producer, Benjamin Michael Tiller, Muresk Institute of Agriculture FORECASTING 7. Can we forecast wheat yields in Western Australia, Senthold Asseng1, Holger Meinke2, and Bill Bowden3, 1CSIRO Plant Industry, 2 APSRU/DPI, 3Agriculture Western Australia ON FARM TESTING 8. On-farm testing, the quiet revolution continues, Jeff Russell1, Ivan Lee2 1Agriculture Western Australia, 2 Farmer Kunjin TopCrop group, Corrigin GRAIN STORAGE 9. CD-ROM tool for growers and advisers: Managing on-farm grain storage – effective practices for the delivery of quality assured products, Clare Johnson1, Chris Newman2 1Quality Wheat CRC Ltd, 2Production Resource Protection Services, Agriculture Western Australia 10. The Internet as a tool for managing grain insects, Robert Emery, Romolo Tassone and Ernestos Kostas, Agriculture Western Australia SUMMER CROPS AND WINDBREAK EFFECT ON YIELD 11. Summer crop Update and agronomic considerations, Graeme Ralph, Pioneer Hi-Bred Australia Pty Ltd 12. The effect of tree windbreaks on grain yield in the medium and low rainfall areas in Western Australia, Robert Sudmeyer, David Hall and Harvey Jones, Agriculture Western Australi

Reconfiguration, contestation, and decline: conceptualizing mature large technical systems

Large technical systems (LTS) are integral to modern lifestyles but arduous to analyze. In this paper, we advance a conceptualization of LTS using the notion of mature “phases,” drawing from insights into innovation studies, science and technology studies, political science, the sociology of infra- structure, history of technology, and governance. We begin by defining LTS as a unit of analysis and explaining its conceptual utility and novelty, situating it among other prominent sociotechnical theories. Next, we argue that after LTS have moved through the (overlapping) phases proposed by Thomas Hughes of invention, expansion, growth, momentum, and style,mature LTS undergo the additional (overlapping) phases of reconfiguration, contestation (subject to pressures such as drift and crisis), and eventually stagnation and decline. We illustrate these analytical phases with historical case studies and the conceptual literature, and close by suggesting future research to refine and develop the LTS framework, particularly related to more refined typologies, temporal dimensions, and a broadening of system users. We aim to contribute to theoretical debates about the coevolution of LTS as well as empirical discussions about system-related use, socio- technical change, and policy-making

IL7 genetic variation and toxicity to immune checkpoint blockade in patients with melanoma

Treatment with immune checkpoint blockade (ICB) frequently triggers immune-related adverse events (irAEs), causing considerable morbidity. In 214 patients receiving ICB for melanoma, we observed increased severe irAE risk in minor allele carriers of rs16906115, intronic to IL7. We found that rs16906115 forms a B cell-specific expression quantitative trait locus (eQTL) to IL7 in patients. Patients carrying the risk allele demonstrate increased pre-treatment B cell IL7 expression, which independently associates with irAE risk, divergent immunoglobulin expression and more B cell receptor mutations. Consistent with the role of IL-7 in T cell development, risk allele carriers have distinct ICB-induced CD8+ T cell subset responses, skewing of T cell clonality and greater proportional repertoire occupancy by large clones. Finally, analysis of TCGA data suggests that risk allele carriers independently have improved melanoma survival. These observations highlight key roles for B cells and IL-7 in both ICB response and toxicity and clinical outcomes in melanoma