Ice formation and its elimination in cryopreservation of oocytes.

Damage from ice and potential toxicity of ice-inhibiting cryoprotective agents (CPAs) are key issues in assisted reproduction of humans, domestic and research animals, and endangered species using cryopreserved oocytes and embryos. The nature of ice formed in bovine oocytes (similar in size to oocytes of humans and most other mammals) after rapid cooling and during rapid warming was examined using synchrotron-based time-resolved x-ray diffraction. Using cooling rates, warming rates and CPA concentrations of current practice, oocytes show no ice after cooling but always develop large ice fractions-consistent with crystallization of most free water-during warming, so most ice-related damage must occur during warming. The detailed behavior of ice at warming depended on the nature of ice formed during cooling. Increasing cooling rates allows oocytes soaked as in current practice to remain essentially ice free during both cooling and warming. Much larger convective warming rates are demonstrated and will allow routine ice-free cryopreservation with smaller CPA concentrations. These results clarify the roles of cooling, warming, and CPA concentration in generating ice in oocytes and establish the structure and grain size of ice formed. Ice formation can be eliminated as a factor affecting post-warming oocyte viability and development in many species, improving outcomes and allowing other deleterious effects of the cryopreservation cycle to be independently studied.

Nine quick tips for open meta-analyses.

Open science principles are revolutionizing the transparency, reproducibility, and accessibility of research. Meta-analysis has become a key technique for synthesizing data across studies in a principled way; however, its impact is contingent on adherence to open science practices. Here, we outline 9 quick tips for open meta-analyses, aimed at guiding researchers to maximize the reach and utility of their findings. We advocate for outlining preregistering clear protocols, opting for open tools and software, and the use of version control systems to ensure transparency and facilitate collaboration. We further emphasize the importance of reproducibility, for example, by sharing search syntax and analysis scripts, and discuss the benefits of planning for dynamic updating to enable living meta-analyses. We also recommend publication in open-access formats, as well as open data, open code, and open access publication. We close by encouraging active promotion of research findings to bridge the gap between complex syntheses and public discourse, and provide a detailed submission checklist to equip researchers, reviewers and journal editors with a structured approach to conducting and reporting open meta-analyses.

Reassessing the Functional Significance of Blood Oxygen Level Dependent Variability.

Blood oxygen level dependent (BOLD) variability (SDBOLD) has emerged as a unique measure of the adaptive properties of neural systems that facilitate fast, stable responding, based on claims that SDBOLD is independent of mean BOLD signal (meanBOLD) and a powerful predictor of behavioral performance. We challenge these two claims. First, the apparent independence of SDBOLD and meanBOLD may reflect the presence of deactivations; we hypothesize that although SDBOLD may not be related to raw meanBOLD, it will be linearly related to "absolute" meanBOLD. Second, the observed relationship between SDBOLD and performance may be an artifact of using fixed-length trials longer than RTs. Such designs provide opportunities to toggle between on- and off-task states, and fast responders likely engage in more frequent state-switching, thereby artificially elevating SDBOLD. We hypothesize that SDBOLD will be higher and more strongly related to performance when using such fixed-length trials relative to self-paced trials that terminate upon a response. We test these two hypotheses in an fMRI study using blocks of fixed-length or self-paced trials. Results confirmed both hypotheses: (1) SDBOLD was robustly related with absolute meanBOLD, and (2) toggling between on- and off-task states during fixed-length trials reliably contributed to SDBOLD. Together, these findings suggest that a reappraisal of the functional significance of SDBOLD as a unique marker of cognitive performance is warranted.

Ice formation and its elimination in cryopreservation of oocytes.

Damage from ice and potential toxicity of ice-inhibiting cryoprotective agents (CPAs) are key issues in assisted reproduction of humans, domestic and research animals, and endangered species using cryopreserved oocytes and embryos. The nature of ice formed in bovine oocytes (similar in size to oocytes of humans and most other mammals) after rapid cooling and during rapid warming were examined using synchrotron-based time-resolved x-ray diffraction. Using cooling rates, warming rates and CPA concentrations of current practice, oocytes show no ice after cooling but always develop large ice fractions - consistent with crystallization of most free water - during warming, so most ice-related damage must occur during warming. The detailed behavior of ice at warming depended on the nature of ice formed during cooling. Increasing cooling rates allows oocytes soaked as in current practice to remain essentially ice free during both cooling and warming. Much larger convective warming rates are demonstrated and will allow routine ice-free cryopreservation with smaller CPA concentrations. These results clarify the roles of cooling, warming, and CPA concentration in generating ice in oocytes and establish the structure and grain size of ice formed. Ice formation can be eliminated as a factor affecting post-thaw oocyte viability and development in many species, improving outcomes and allowing other deleterious effects of the cryopreservation cycle to be independently studied.

Changes in an enzyme ensemble during catalysis observed by high-resolution XFEL crystallography.

Enzymes populate ensembles of structures necessary for catalysis that are difficult to experimentally characterize. We use time-resolved mix-and-inject serial crystallography at an x-ray free electron laser to observe catalysis in a designed mutant isocyanide hydratase (ICH) enzyme that enhances sampling of important minor conformations. The active site exists in a mixture of conformations, and formation of the thioimidate intermediate selects for catalytically competent substates. The influence of cysteine ionization on the ICH ensemble is validated by determining structures of the enzyme at multiple pH values. Large molecular dynamics simulations in crystallo and time-resolved electron density maps show that Asp17 ionizes during catalysis and causes conformational changes that propagate across the dimer, permitting water to enter the active site for intermediate hydrolysis. ICH exhibits a tight coupling between ionization of active site residues and catalysis-activated protein motions, exemplifying a mechanism of electrostatic control of enzyme dynamics.

A precision-mapping approach to physical exercise interventions targeting cognitive function.

Physical exercise confers numerous benefits to brain structure, function and cognition, however, considerable individual variability exists in these effects. Emerging paradigms focused on intraindividual dynamics provide novel opportunities to map and leverage individualized neural architectures underlying exercise-cognition relationships. Progress at the intersection of psychometrics, structural and functional neuroimaging, electrophysiology, and genetics can be integrated to elucidate each individual's potential for improvement, as well as the specific abilities that are most likely to benefit from exercise regimens. These personalized profiles can then guide targeted exercise programs tailored to effectively modulate the pathways identified as most promising for that individual. Such mapping-guided exercise interventions tailored to a person's neurocognitive profile allows optimizing cognitive improvements compared to results elicited by generic regimens. While still in its infancy, precision interventions represent an innovative future direction to advance exercise in support of brain health, toward potent, truly personalized cognitive enhancement.

Printable devices for neurotechnology.

Printable electronics for neurotechnology is a rapidly emerging field that leverages various printing techniques to fabricate electronic devices, offering advantages in rapid prototyping, scalability, and cost-effectiveness. These devices have promising applications in neurobiology, enabling the recording of neuronal signals and controlled drug delivery. This review provides an overview of printing techniques, materials used in neural device fabrication, and their applications. The printing techniques discussed include inkjet, screen printing, flexographic printing, 3D printing, and more. Each method has its unique advantages and challenges, ranging from precise printing and high resolution to material compatibility and scalability. Selecting the right materials for printable devices is crucial, considering factors like biocompatibility, flexibility, electrical properties, and durability. Conductive materials such as metallic nanoparticles and conducting polymers are commonly used in neurotechnology. Dielectric materials, like polyimide and polycaprolactone, play a vital role in device fabrication. Applications of printable devices in neurotechnology encompass various neuroprobes, electrocorticography arrays, and microelectrode arrays. These devices offer flexibility, biocompatibility, and scalability, making them cost-effective and suitable for preclinical research. However, several challenges need to be addressed, including biocompatibility, precision, electrical performance, long-term stability, and regulatory hurdles. This review highlights the potential of printable electronics in advancing our understanding of the brain and treating neurological disorders while emphasizing the importance of overcoming these challenges.

A guide for social science journal editors on easing into open science.

Journal editors have a large amount of power to advance open science in their respective fields by incentivising and mandating open policies and practices at their journals. The Data PASS Journal Editors Discussion Interface (JEDI, an online community for social science journal editors: www.dpjedi.org ) has collated several resources on embedding open science in journal editing ( www.dpjedi.org/resources ). However, it can be overwhelming as an editor new to open science practices to know where to start. For this reason, we created a guide for journal editors on how to get started with open science. The guide outlines steps that editors can take to implement open policies and practices within their journal, and goes through the what, why, how, and worries of each policy and practice. This manuscript introduces and summarizes the guide (full guide: https://doi.org/10.31219/osf.io/hstcx ).

Can the prosocial benefits of episodic simulation transfer to different people and situational contexts?

Previous research has found that episodic simulation of events of helping others can effectively enhance intentions to help the same person involved and the identical situational context as the imagined scenarios. This 'prosocial simulation effect' is argued to reflect, at least in part, associative memory mechanisms whereby the simulation is reactivated when in the same situation as that imagined. However, to date, no study has examined systematically whether this 'prosocial simulation effect' can be transferred to response scenarios involving different people and/or situational contexts to the imagined scenarios, and if so, whether the degree of overlap with the imagined helping episode modulated the transfer effect. Across two experiments, we systematically varied the overlap of the simulated and response scenarios, both in terms of the persons in need and/or the situational contexts, and whether would influence the magnitude of prosocial simulation effect. Results from both experiments showed that the prosocial simulation effect can be transferred to response scenarios involving different people and situational contexts to the simulated scenarios. However, this finding was primarily driven by response scenarios that had a high degree of overlap to the simulated scenarios. The application of our findings to the practical implementation of simulation to promote prosociality in the real world is discussed.

Validation of an open source, remote web-based eye-tracking method (WebGazer) for research in early childhood.

Measuring eye movements remotely via the participant's webcam promises to be an attractive methodological addition to in-person eye-tracking in the lab. However, there is a lack of systematic research comparing remote web-based eye-tracking with in-lab eye-tracking in young children. We report a multi-lab study that compared these two measures in an anticipatory looking task with toddlers using WebGazer.js and jsPsych. Results of our remotely tested sample of 18-27-month-old toddlers (N = 125) revealed that web-based eye-tracking successfully captured goal-based action predictions, although the proportion of the goal-directed anticipatory looking was lower compared to the in-lab sample (N = 70). As expected, attrition rate was substantially higher in the web-based (42%) than the in-lab sample (10%). Excluding trials based on visual inspection of the match of time-locked gaze coordinates and the participant's webcam video overlayed on the stimuli was an important preprocessing step to reduce noise in the data. We discuss the use of this remote web-based method in comparison with other current methodological innovations. Our study demonstrates that remote web-based eye-tracking can be a useful tool for testing toddlers, facilitating recruitment of larger and more diverse samples; a caveat to consider is the larger drop-out rate.

Ice formation and its elimination in cryopreservation of bovine oocytes.

Damage from ice and potential toxicity of ice-inhibiting cryoprotective agents (CPAs) are key issues in assisted reproduction using cryopreserved oocytes and embryos. We use synchrotron-based time-resolved x-ray diffraction and tools from protein cryocrystallography to characterize ice formation within bovine oocytes after cooling at rates between ∼1000 °C/min and ∼600,000°C /min and during warming at rates between 20,000 and 150,000 °C /min. Maximum crystalline ice diffraction intensity, maximum ice volume, and maximum ice grain size are always observed during warming. All decrease with increasing CPA concentration, consistent with the decreasing free water fraction. With the cooling rates, warming rates and CPA concentrations of current practice, oocytes may show no ice after cooling but always develop substantial ice fractions on warming, and modestly reducing CPA concentrations causes substantial ice to form during cooling. With much larger cooling and warming rates achieved using cryocrystallography tools, oocytes soaked as in current practice remain essentially ice free during both cooling and warming, and when soaked in half-strength CPA solution oocytes remain ice free after cooling and develop small grain ice during warming. These results clarify the roles of cooling, warming, and CPA concentration in generating ice in oocytes, establish the character of ice formed, and suggest that substantial further improvements in warming rates are feasible. Ice formation can be eliminated as a factor affecting post-thaw oocyte viability and development, allowing other deleterious effects of the cryopreservation cycle to be studied, and osmotic stress and CPA toxicity reduced. Significance Statement: Cryopreservation of oocytes and embryos is critical in assisted reproduction of humans and domestic animals and in preservation of endangered species. Success rates are limited by damage from crystalline ice, toxicity of cryoprotective agents (CPAs), and damage from osmotic stress. Time-resolved x-ray diffraction of bovine oocytes shows that ice forms much more readily during warming than during cooling, that maximum ice fractions always occur during warming, and that the tools and large CPA concentrations of current protocols can at best only prevent ice formation during cooling. Using tools from cryocrystallography that give dramatically larger cooling and warming rates, ice formation can be completely eliminated and required CPA concentrations substantially reduced, expanding the scope for species-specific optimization of post-thaw reproductive outcomes.

Implementing code review in the scientific workflow: Insights from ecology and evolutionary biology.

Code review increases reliability and improves reproducibility of research. As such, code review is an inevitable step in software development and is common in fields such as computer science. However, despite its importance, code review is noticeably lacking in ecology and evolutionary biology. This is problematic as it facilitates the propagation of coding errors and a reduction in reproducibility and reliability of published results. To address this, we provide a detailed commentary on how to effectively review code, how to set up your project to enable this form of review and detail its possible implementation at several stages throughout the research process. This guide serves as a primer for code review, and adoption of the principles and advice here will go a long way in promoting more open, reliable, and transparent ecology and evolutionary biology.

Genomics might not be the solution, but epistemic validity remains a challenge in the social sciences.

We sympathize with many of the points Burt makes in challenging the value of genetics to advance our understanding of social science. Here, we discuss how recent reflections on epistemic validity in the behavioral sciences can further contribute to a reappraisal of the role of sociogenomics to explain and predict human traits, aptitudes, and achievement.

Increasing the transparency of systematic reviews: presenting a generalized registration form.

This paper presents a generalized registration form for systematic reviews that can be used when currently available forms are not adequate. The form is designed to be applicable across disciplines (i.e., psychology, economics, law, physics, or any other field) and across review types (i.e., scoping review, review of qualitative studies, meta-analysis, or any other type of review). That means that the reviewed records may include research reports as well as archive documents, case law, books, poems, etc. Items were selected and formulated to optimize broad applicability instead of specificity, forgoing some benefits afforded by a tighter focus. This PRISMA 2020 compliant form is a fallback for more specialized forms and can be used if no specialized form or registration platform is available. When accessing this form on the Open Science Framework website, users will therefore first be guided to specialized forms when they exist. In addition to this use case, the form can also serve as a starting point for creating registration forms that cater to specific fields or review types.

Systems factorial technology provides novel insights into the cognitive processing characteristics of open-skill athletes.

Sport expertise has been shown to modulate the cognitive advantage in open-skill athletes, with evidence for a greater advantage for athletes practicing interceptive sports relative to strategic sports. However, this conclusion is solely based on central tendency measures such as accuracy or mean reaction time (RT), dismissing important information embedded in the intra-individual temporal dynamics of cognitive performance. This study aimed to better understand the cognitive advantage associated with open-skill sports, with a non-parametric approach assessing cognitive process at the level of RT distribution (i.e., systems factorial technology, SFT). Twenty-eight interceptive sport athletes, 27 strategic sport athletes, and 26 physically active non-athletes performed a go/nogo version of the redundant target task to assess their processing capacity of simultaneously monitoring multiple information channels. SFT was applied to assess resilience capacity, an estimate of workload capacity underlying inhibitory control. Our findings showed that interceptive sport athletes exhibited shorter mean RT relative to non-athletes selectively in the task condition involving distracting information, while strategic sport athletes showed greater resilience capacity over earlier responses relative to the other groups. These findings suggest that the two types of open-skill sports may be associated with different processing specificity, possibly reflecting the domain-specific rules and requirements.

Examining the relationship between aerobic fitness and cognitive control processes: An SFT and ERP study.

Previous studies have demonstrated a positive relationship between aerobic fitness and cognitive control, the ability to inhibit distractions (conflict control) or impulsive actions (response inhibition). However, it is unknown whether these sub-processes and their underlying information processing capacity are differentially related to aerobic fitness. To address this question, we employed a go/no-go version of the redundant-target task, which was administered concurrently with the recording of event-related potentials (ERPs) and the use of a reaction-time based diagnostic tool known as system factorial technology (SFT). Our sample consisted of 46 young male adults with varying levels of aerobic fitness: the high-fit group (n = 23; aged 21.33 ± 2.44 years; VO2max 58.83 ± 6.93 ml/kg/min) and the low-fit group (n = 23; aged 22.30 ± 1.40 years; VO2max 41.90 ± 4.01 ml/kg/min). The results showed that the high-fit group exhibited a lower false-alarm rate compared to the low-fit group. However, there was no difference in processing speed between the two groups. The SFT analysis revealed that the high-fit group had more efficient information processing for earlier responses, but not later responses, compared to the low-fit group. Analysis of the ERPs indicated that the high-fit group had larger N2d amplitudes and shorter P3d latencies during conflict control compared to the low-fit group, while there were no such effects for the process of response inhibition. These findings suggest that aerobic fitness may be differentially related to the temporal dynamics and sub-processes of cognitive control.

XFEL Microcrystallography of Self-Assembling Silver n-Alkanethiolates.

New synthetic hybrid materials and their increasing complexity have placed growing demands on crystal growth for single-crystal X-ray diffraction analysis. Unfortunately, not all chemical systems are conducive to the isolation of single crystals for traditional characterization. Here, small-molecule serial femtosecond crystallography (smSFX) at atomic resolution (0.833 Å) is employed to characterize microcrystalline silver n-alkanethiolates with various alkyl chain lengths at X-ray free electron laser facilities, resolving long-standing controversies regarding the atomic connectivity and odd-even effects of layer stacking. smSFX provides high-quality crystal structures directly from the powder of the true unknowns, a capability that is particularly useful for systems having notoriously small or defective crystals. We present crystal structures of silver n-butanethiolate (C4), silver n-hexanethiolate (C6), and silver n-nonanethiolate (C9). We show that an odd-even effect originates from the orientation of the terminal methyl group and its role in packing efficiency. We also propose a secondary odd-even effect involving multiple mosaic blocks in the crystals containing even-numbered chains, identified by selected-area electron diffraction measurements. We conclude with a discussion of the merits of the synthetic preparation for the preparation of microdiffraction specimens and compare the long-range order in these crystals to that of self-assembled monolayers.

Development of an Injury Risk Function for the Anterior Pelvis Under Frontal Lap Belt Loading Conditions.

Iliac wing fractures due to lap belt loading have been identified in laboratory tests for almost 50 years and an analysis of recent data suggests these injuries are also occurring in the field. With the introduction of highly autonomous vehicles on the horizon, vehicle manufacturers are exploring open cabin concepts that permit reclined postures and separation of the occupant from the knee bolster and instrument panel. This will result in greater reliance on the lap belt and lap belt/pelvis loading to restrain occupants. No injury criteria exist for iliac wing fractures resulting from lap belt loading like that seen in frontal crash conditions. This study tested the tolerance of isolated iliac wings in a controlled lap belt-like loading environment while incorporating the effect of loading angle after analyzing lap belt loading experiments from a previous study. Twenty-two iliac wings were tested; nineteen of them sustained fracture (exact), but the loading input was insufficient to cause fracture in the other three (right censored). The fracture tolerance of the tested specimens ranged widely (1463-8895 N) and averaged 4091 N (SD 2381 N). Injury risk functions were created by fitting Weibull survival models to data that integrated censored and exact failure observations.