1,721,004 research outputs found
From Mars to humans: interactive Raman spectroscopy-based outreach activities
No full textOutreach activities can directly influence educational development and career trajectory; while also promoting the institutions that produce them. Science, technology, engineering, and mathematics (STEM) is fundamental to development, pushing forward technological advancements and laying the path to new frontiers. This paper aims to provide an overview of an outreach event with a framework that can be developed into a novel teaching tool, showcasing collaboration across multiple STEM subjects: Chemistry, Physics, Biology and Engineering. From Mars to Humans is an interactive educational outreach project, developing the fundamentals needed to understand Raman spectroscopy and its many applications on earth and beyond. This interdisciplinary demonstration includes several devices and models developed by the Biophotonics and Imaging research group at the University of Southampton. We will cover the design and function of “Dr Raman” and the “Raman for Life Rover (R4L)”, two interactive activity devices that have been developed using state-of-the-art spectroscopy technology. These devices help translate the understanding of light-matter interactions to real-life applications, focusing on current popular media topics, public health and interplanetary discovery. Additionally, we demonstrate how these devices within the outreach event can inspire a new generation of scientists, utilising how the underpinning science is leading new transformative technologies and advancing human endeavour. From Mars to Humans activity was deployed for the Southampton Science and Engineering Festival (SOTSEF 2022) and received excellent feedback from visitors. We will present the public engagement framework that led to this achievement, analyse the feedback and engagement criteria of the activity, and summarise goals for the future
Perpetual sedimentation open instrumentation
No full textThis page describes how to build rotating syringe pumps suitable for Drop-seq microfluidics and many other applications.</span
Meiotic spindle assembly checkpoint and aneuploidy in males versus females
Full text linkThe production of gametes (sperm and eggs in mammals) involves two sequential cell divisions, meiosis I and meiosis II. In meiosis I, homologous chromosomes segregate to different daughter cells, and meiosis II resembles mitotic divisions in that sister chromatids separate. While in principle the process is identical in males and females, the time frame and susceptibility to chromosomal defects, including achiasmy and cohesion weakening, and the response to mis-segregating chromosomes are not. In this review, we compare and contrast meiotic spindle assembly checkpoint function and aneuploidy in the two sexes.</p
The sensitivity of the DNA damage checkpoint prevents oocyte maturation in endometriosis
No full textMouse oocytes respond to DNA damage by arresting in meiosis I through activity of the Spindle Assembly Checkpoint (SAC) and DNA Damage Response (DDR) pathways. It is currently not known if DNA damage is the primary trigger for arrest, or if the pathway is sensitive to levels of DNA damage experienced physiologically. Here, using follicular fluid from patients with the disease endometriosis, which affects 10% of women and is associated with reduced fertility, we find raised levels of Reactive Oxygen Species (ROS), which generate DNA damage and turn on the DDR-SAC pathway. Only follicular fluid from patients with endometriosis, and not controls, produced ROS and damaged DNA in the oocyte. This activated ATM kinase, leading to SAC mediated metaphase I arrest. Completion of meiosis I could be restored by ROS scavengers, showing this is the primary trigger for arrest and offering a novel clinical therapeutic treatment. This study establishes a clinical relevance to the DDR induced SAC in oocytes. It helps explain how oocytes respond to a highly prevalent human disease and the reduced fertility associated with endometriosis
Imaging chromosome separation in mouse oocytes by responsive 3D confocal timelapse microscopy
No full textAccurate chromosome segregation is necessary so that genetic material is equally shared among daughter cells. However, maturing mammalian oocytes are particularly prone to chromosome segregation errors, making them a valuable tool for identifying the causes of mis-segregation. Factors such as aging, cohesion loss, DNA damage, and the roles of a plethora of kinetochore and cell cycle-related proteins are involved. To study chromosome segregation in oocytes in a live setting is an imaging challenge that requires advanced techniques. Here we describe a method for examining chromosomes in live oocytes in detail as they undergo maturation. Our method is based on tracking the "center of brightness" of fluorescently labeled chromosomes. Here we describe how to set up our software and run experiments on a Leica TCS SP8 confocal microscope, but the method would be transferable to other microscopes with computer-aided microscopy.</p
DNA damage induces a meiotic arrest in mouse oocytes mediated by the spindle assembly checkpoint
No full textExtensive damage to maternal DNA during meiosis causes infertility, birth defects and abortions. However, it is unknown if fully grown oocytes have a mechanism to prevent the creation of DNA-damaged embryos. Here we show that DNA damage activates a pathway involving the spindle assembly checkpoint (SAC) in response to chemically induced double strand breaks, UVB and ionizing radiation. DNA damage can occur either before or after nuclear envelope breakdown, and provides an effective block to anaphase-promoting complex activity, and consequently the formation of mature eggs. This contrasts with somatic cells, where DNA damage fails to affect mitotic progression. However, it uncovers a second function for the meiotic SAC, which in the context of detecting microtubule-kinetochore errors has hitherto been labelled as weak or ineffectual in mammalian oocytes. We propose that its essential role in the detection of DNA damage sheds new light on its biological purpose in mammalian female meiosis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Chromosome biorientation and APC activity remain uncoupled in oocytes with reduced volume
Full text linkThe spindle assembly checkpoint (SAC) prevents chromosome mis-segregation by coupling anaphase-onset with correct chromosome attachment and tension to microtubules. It does this by generating a diffusible signal from free kinetochores into the cytoplasm, inhibiting the anaphase-promoting complex (APC). The volume in which this signal remains effective is unknown. This raises the possibility that cell volume may be the reason why the SAC is weak, and chromosome segregation error-prone, in mammalian oocytes. Here, by a process of serial bisection, we analyzed the influence of oocyte volume on the ability of the SAC to inhibit bivalent segregation in meiosis I. We were able to generate oocytes with cytoplasmic volumes reduced by 86% and observed changes in APC activity consistent with increased SAC control. However, bivalent biorientation remained uncoupled from APC activity, leading to error-prone chromosome segregation. We conclude that volume is one factor contributing to SAC weakness in oocytes. However additional factors likely uncouple chromosome biorientation with APC activity
Peritoneal Fluid Modulates Redox Balance and RNA Integrity in Mouse Oocytes: Insights into Endometriosis-Related Oxidative Stress
No full textReactive oxygen species (ROS) are vital for oocyte development, yet the redox state of peritoneal fluid may differ between health and disease. This study investigates the effects of peritoneal fluid from women with and without endometriosis on mouse oocytes’ redox status and RNA oxidation. Peritoneal fluid samples were collected during laparoscopy from women enrolled in an ethically approved case–control study. Stimulated C57BL6 mouse germinal vesicle oocytes were microinjected with RNA transcribed from a Grx1-roGFP2 construct and imaged to assess redox changes. Further oocytes were incubated in standard media, H2O2, or 20% peritoneal fluid, fixed, and immunostained for 8-OHG to evaluate RNA oxidative damage. Oocytes exposed to endometriosis-affected peritoneal fluid showed significantly less redox reduction (mean change 0.07, p p p p < 0.001). These findings suggest an altered oxidative environment of peritoneal fluid in endometriosis may contribute to impaired oocyte quality, highlighting a potential mechanism of infertility in affected women
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