Continuous flow for materials synthesis, assembly and crystallisation at Diamond: discovery and delivery of high value materials

Continuous crystallisation of the model system Carbamazepine (CBZ) in ethanol in the KRAIC-D (Kinetically Regulated Automated Input Crystalliser - Diffraction) platform on beamline I11 (high resolution powder diffraction) is presented. The effect of introducing a controlled solid interface into the crystallisation process is investigated, where CBZ form III seeds are introduced in polymorphic purity at different seeding positions (pre- and post-nucleation) throughout the length of the KRAIC-D. The video associated with Chapter 4 corresponds with a post-nucleation CBZ form III experiment where a separation of crystal habit is observed as a result of the different interaction with the flow paths in the solution slugs with the segmented flow. The second device is the KRAIC-S (Kinetically Regulated Automated Input Crystalliser - Single Crystal) platform installed at I19 (small molecule single crystal beamline) employed to investigate the continuous crystallisation of paracetamol (PCM) in 60:40 water:isopropanol via a range of experiments including unseeded and seeded cooling crystallisations. The unseeded experiments also looked at the crystallisation at different set points along the KRAIC-S (6.7 m and 8.7 m) to investigate crystal growth and crystal rotation at different length scales. The videos associated with Chapter 5 include single crystals produced from the range of experiments investigated. Each video tracks a different single crystal in a solution slug, where through use of the slug triggering mechanism, whereby an optical trigger prompts translation of the motorised stage to artificially suspend the single crystal in the X-ray beam during data collection. These videos complement the diffraction data and can provide explanation for data collections, which do not achieve cell indexation as the single crystal is shown to move in and out of the X-ray beam in these videos.Videos obtained using Camera positioned by X-ray beam on beamline I19, the small molecule single crystal beamline at Diamond Light Source

Transferable neural networks for enhanced sampling of protein dynamics

Variational auto-encoder frameworks have demonstrated success in reducing complex nonlinear dynamics in molecular simulation to a single non-linear embedding. In this work, we illustrate how this non-linear latent embedding can be used as a collective variable for enhanced sampling, and present a simple modification that allows us to rapidly perform sampling in multiple related systems. We first demonstrate our method is able to describe the effects of force field changes in capped alanine dipeptide after learning a model using AMBER99. We further provide a simple extension to variational dynamics encoders that allows the model to be trained in a more efficient manner on larger systems by encoding the outputs of a linear transformation using time-structure based independent component analysis (tICA). Using this technique, we show how such a model trained for one protein, the WW domain, can efficiently be transferred to perform enhanced sampling on a related mutant protein, the GTT mutation. This method shows promise for its ability to rapidly sample related systems using a single transferable collective variable and is generally applicable to sets of related simulations, enabling us to probe the effects of variation in increasingly large systems of biophysical interest.Comment: 20 pages, 10 figure

Greater Sage-Grouse Brood Responses to Livestock Grazing in Sagebrush Rangelands

The distribution and abundance of the greater sage-grouse (Centrocercus urophasianus; sage-grouse) have declined in the last 60 years. Range contractions and population declines have been attributed to loss and fragmentation of their sagebrush (Artemisia spp.) habitats. Grazing by livestock remains the predominant anthropogenic land-use across sagebrush ecosystems in North America, occurring on 87% of remaining sage-grouse habitat. Most of the peer-reviewed literature reports the potential for negative impacts of sagebrush reduction treatments, to increase livestock forage, on sage-grouse habitat. However, few studies have linked livestock grazing at the landscape level to vital rates (e.g., nest initiation rates, nest success, brood movements, and brood success) for ground-nesting birds such as sage-grouse. We analyzed brood habitat selection of sage-grouse in response to vegetation dynamics and, where possible (DLL), in interaction with livestock grazing to determine whether the relationship between sage-grouse and cattle is competitive or facilitative. This research adds new information to the literature pertaining to the knowledge gap between livestock grazing and whether it is facilitative or competitive with brooding sage-grouse. Our results suggest that the relationship between livestock and sage-grouse might be competitive on the short term but facilitative over longer time scales. These findings indicate that deferred-rest rotational grazing practices may allow for spatio-temporal segregation, enhancing the capacity for sage-grouse to optimize the exploitation of available forage while avoiding direct contact with livestock. Further, our results suggest that livestock grazing could have carry-over effects on vegetation dynamics that may benefit sage-grouse in subsequent seasons, although we did not test this directly; more research is needed to understand the effects of livestock grazing across multiple growing seasons

The effects of a 12-Month, small changes group intervention on weight loss and menopausal symptoms in overweight women

To better understand how psychological principles related to goal-setting and motivation can be applied to the problem of obesity and menopausal symptoms, we examined the effectiveness of a Small Changes Intervention (SCI) program on forty-five overweight (BMI = 33.67 ± 7.03) women (mean age = 50.14 ± 12.16). Grounded in task motivation theory (cf. Locke & Latham, 2002), our SCI group therapy approach instituted small and maintainable steps in nutrition and physical activity to promote weight loss and a reduction in menopausal symptoms. Body weight, Body Mass Index (BMI), and scores on the Greene Climacteric Scale were assessed at Baseline (pre-intervention), 3-month post-treatment, 6-month follow-up, and 12-month follow-up. By the end of the 12-month study, 20 women were still participating and had lost, on average, 6.4% of their body weight, and had experienced a significant reduction in BMI, (BMI = 30.9 ± 6.13), providing further support for the SCI approach as an effective weight loss intervention method. Cross-sectional correlational analyses found expected associations between obesity and menopausal symptoms at the follow-up assessments. These relationships were especially strong by the last assessment period. Most importantly, menopausal symptoms decreased over the duration of the intervention. Taken together, these results suggest that the longitudinal impact of SCI on weight and BMI can have a positive impact on menopausal symptoms. These findings underscore the importance of applying wellresearched social psychological principles in goal setting to the problem of obesity and menopausal symptoms. Furthermore, the results obtained from the SCI approach suggest that that while obese individuals may experience increased symptoms of menopause, the process of losing excess body weight through achievement of small, achievable goals has the potential to improve menopausal symptoms

Investigating the role of boundary bricks in DNA brick self-assembly

In the standard DNA brick set-up, distinct 32-nucleotide strands of single-stranded DNA are each designed to bind specifically to four other such molecules. Experimentally, it has been demonstrated that the overall yield is increased if certain bricks which occur on the outer faces of target structures are merged with adjacent bricks. However, it is not well understood by what mechanism such `boundary bricks' increase the yield, as they likely influence both the nucleation process and the final stability of the target structure. Here, we use Monte Carlo simulations with a patchy particle model of DNA bricks to investigate the role of boundary bricks in the self-assembly of complex multicomponent target structures. We demonstrate that boundary bricks lower the free-energy barrier to nucleation and that boundary bricks on edges stabilize the final structure. However, boundary bricks are also more prone to aggregation, as they can stabilize partially assembled intermediates. We explore some design strategies that permit us to benefit from the stabilizing role of boundary bricks whilst minimizing their ability to hinder assembly; in particular, we show that maximizing the total number of boundary bricks is not an optimal strategy.This work was supported by the Engineering and Physical Sciences Research Council [Programme Grant EP/I001352/1]. HKWS acknowledges support from the Winston Churchill Foundation of the United States. Research carried out in part at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the US Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-SC0012704

In situ non-invasive Raman spectroscopic characterisation of succinic acid polymorphism during segmented flow crystallisation

The kinetically regulated automated input crystalliser for Raman spectroscopy (KRAIC-R) combines highly controlled crystallisation environments, via tri segmented flow, with non-invasive confocal Raman spectroscopy. Taking advantage of the highly reproducible crystallisation environment within a segmented flow crystalliser and the non-invasive nature of confocal spectroscopy, we are able to shine light on the nucleation and growth of Raman active polymorphic materials without inducing unrepresentative crystallisation events through our analysis technique. Using the KRAIC-R we have probed the nucleation and subsequent growth of succinic acid. Succinic acid typically crystallises as β-SA from solution-based crystallisation although some examples of a small proportion of α-SA have been reported in the β-SA product. Here we show that α-SA and β-SA nucleate concomitantly but undergo Ostwald ripening to a predominantly β-SA product

Supracervical Robotic-Assisted Laparoscopic Sacrocolpopexy for Pelvic Organ Prolapse

Supracervical robotic-assisted laparoscopic sacrocolpopexy was found to be an effective repair of apical vaginal defects in patients with pelvic organ prolapse who had not undergone previous hysterectomy

Listening to the Voices of Community Health Workers: A Multilevel, Culture-Centered Approach to Overcoming Structural Barriers in U.S. Latinx Communities

Community Health Workers (CHWs) are often incorporated into efforts to reduce health disparities for vulnerable populations. However, their voices are rarely the focus of research when considering how to increase their job effectiveness and sustainability. The current study addresses this gap by privileging the voices of 28 CHWs who work with Latinx communities in Nebraska through in-depth, semi-structured interviews. Using a multilevel, Culture-Centered Approach (CCA) to Health Communication, we identified two key structural communication issues: (a) increasing language accommodation and (b) increasing (and stabilizing) network integration across three ecological levels of health behavior (individual, microsystem, and exosystem). This study shows the uniquely valuable perspective that CHWs have as they navigate hierarchical health care structures and community cultures to meet the needs of their Latinx clients. Findings suggest that CHWs should be included in health care organization and policy discussions to reduce health disparities for Latinx populations