Structural Properties, Order-Disorder Phenomena and Phase Stability of Orotic Acid Crystal Forms

Orotic acid (OTA) is reported to exist in the anhydrous (AH), monohydrate (Hy1) and dimethylsulfoxide monosolvate (SDMSO) forms. In this study we investigate the (de)hydration/desolvation behavior, aiming at an understanding of the elusive structural features of anhydrous OTA by a combination of experimental and computational techniques, namely, thermal analytical methods, gravimetric moisture (de)sorption studies, water activity measurements, X-ray powder diffraction, spectroscopy (vibrational, solid-state NMR), crystal energy landscape and chemical shift calculations. The Hy1 is a highly stable hydrate, which dissociates above 135°C and loses only a small part of the water when stored over desiccants (25°C) for more than one year. In Hy1, orotic acid and water molecules are linked by strong hydrogen bonds in nearly perfectly planar arranged stacked layers. The layers are spaced by 3.1 Å and not linked via hydrogen-bonds. Upon dehydration the X-ray powder diffraction and solid-state NMR peaks become broader indicating some disorder in the anhydrous form. The Hy1 stacking reflection (122) is maintained, suggesting that the OTA molecules are still arranged in stacked layers in the dehydration product. Desolvation of SDMSO, a non-layer structure, results in the same AH phase as observed upon dehydrating Hy1. Depending on the desolvation conditions different levels of order-disorder of layers present in anhydrous OTA are observed, which is also suggested by the computed low energy crystal structures. These structures provide models for stacking faults as intergrowth of different layers is possible. The variability in anhydrate crystals is of practical concern as it affects the moisture dependent stability of AH with respect to hydration

Aboriginal uses of seaweeds in temperate Australia: an archival assessment

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record.Global demand for seaweed has increased dramatically over recent decades and the potential for seaweed aquaculture to address issues around food security and climate-change mitigation are being recognised. Australia is a global hotspot for seaweed biodiversity with a rich, diverse Indigenous history dating back 65,000 years, including an extensive traditional knowledge of Australian natural resources. In our present review of archival literature, we explored the contemporary and historical uses and cultural significance of seaweeds to Indigenous Australians. We found records of seaweed use by Indigenous Saltwater Australians (Australian Aboriginal peoples from coastal areas across the nation who are the Traditional Owners/Guardians and custodians of the lands and waters characterised by saltwater environment) for a variety of purposes including cultural activities, ceremonial activities, medicinal uses, clothing, cultural history, food, fishing, shelter and domestic uses. Species-specific records were rarely recorded (and/or accurately translated) in the archival literature, with the exception of the use of the fucoid bull kelp, Durvillaea potatorum, which was prevalent. Our research is a step forward in the important task of recovering and conserving Indigenous Australian knowledge and customary traditions surrounding coastal resource use. Unlocking this knowledge creates opportunities for the continuance and revitalization of traditional customary practises that may enable innovative Indigenous business activities and product creation, based around food, sustainable natural-fibre technologies and health. Such research also has the potential to enhance a developing Australian seaweed industry by guiding species selection, preparation, use and sustainable resource management. We recommend our findings are used to inform the direction and locations of further research conducted in conjunction with Indigenous coastal communities in Australia’s temperate regions, to explore in more detail the Indigenous Australian’s historical heritage associated with coastal seaweed resources and their uses

The new talent management challenges of industry 4.0

Purpose: The transformational changes to business environments brought about by the fourth industrial revolution create a perfect storm for strategic human resource management, prompting a need to explore the implications of this context for talent management theory and practice. Design/methodology/approach: In-depth interviews were conducted with HR Directors and Senior Leaders within engineering-led organisations to explore current challenges experienced across each stage of the talent pipeline: attraction and recruitment, training and development, career development, talent mobility, and succession planning. Findings: The speed of technological change brought about by Industry 4.0 had created a significant gap between current capability of employees and the rapidly evolving requirements of their roles, prompting a need to consider new and more effective approaches to talent development. Middle managers are increasingly recognised as overlooked critical talent within this context of unprecedented change, given their essential role in change management. In addition, whilst lateral hiring remains a common talent management practice, in the case of Industry 4.0 this equates to fighting a war for talent that does not exist. Practical implications: This study suggests that there is a need for evolution of talent management theory and practice towards a more dynamic, systems-thinking orientation, acknowledging the interrelated nature of different talent management activities. Originality/value: This paper provides an in-depth insight into the impact of the unprecedented change brought about by Industry 4.0 on contemporary talent management practice, considering how theory and practice might need to evolve to enable individuals and organisations to keep up with the rate of technological change

Inner disc rearrangement revealed by dramatic brightness variations in the young star PV Cep

Young Sun-like stars at the beginning of the pre-main sequence (PMS) evolution are surrounded by accretion discs and remnant protostellar envelopes. Photometric and spectroscopic variations of these stars are driven by interactions of the star with the disc. Time scales and wavelength dependence of the variability carry information on the physical mechanisms behind these interactions. We conducted multi-epoch, multi-wavelength study of PV Cep, a strongly variable, accreting PMS star. By combining our own observations from 2004-2010 with archival and literature data, we show that PV Cep started a spectacular fading in 2005, reaching an I_C-band amplitude of 4 mag. Analysis of variation of the optical and infrared fluxes, colour indices, and emission line fluxes suggests that the photometric decline in 2005-2009 resulted from an interplay between variable accretion and circumstellar extinction: since the central luminosity of the system is dominated by accretion, a modest drop in the accretion rate could induce the drastic restructuring of the inner disc. Dust condensation in the inner disc region might have resulted in the enhancement of the circumstellar extinction.Comment: 11 pages, 4 figures, accepted for publication by MNRAS. 3 online tables adde

Mechanically Induced Amorphization of Diaqua-bis(Omeprazolate)-Magnesium Dihydrate

The influence of milling diaqua-bis(omeprazolate)-magnesium dihydrate (DABOMD), an active pharmaceutical ingredient (API), was investigated. DABOMD was processed in a planetary ball mill at different milling times, from 1 to 300 min. The milling process resulted in a prominent comminution (size reduction) and amorphization of the API. DABOMD amorphization was identified with various characterization techniques including thermogravimetric analysis, differential scanning calorimetry, powder X-ray diffraction, and attenuated total reflection-Fourier transform infrared spectroscopy. The solid–solid crystalline to amorphous phase transformation is driven by compression, shear stresses, and heat generated in the planetary ball mill. This leads to distortion and breakage of hydrogen bonds, release of water molecules from the crystalline lattice of DABOMD and the accumulation of defects, and eventually a collapse of the crystalline order. Model fitting of the kinetics of comminution and the amorphization of DABOMD revealed a series of events: a rapid comminution at the start of milling driven by crystal cleavage of DABOMD, followed by partial amorphization, which is driven by rapid water diffusion, and subsequently, a slow steady comminution and amorphization

Deep brain stimulation for tremor resulting from acquired brain injury

OBJECTIVES: To evaluate the efficacy of deep brain stimulation (DBS) in the treatment of tremor resulting from acquired brain injury (ABI). METHODS: A series of eight consecutive patients with post-ABI tremor were treated with DBS of the ventro-oralis posterior (VOP)/zona incerta (ZI) region, and subsequently underwent blinded assessments using Bain's tremor severity scale. RESULTS: VOP/ZI DBS produced a mean reduction in tremor severity of 80.75% based on Bain's tremor severity scale, with significant reductions in all five component tremor subscores: rest, postural, kinetic, proximal and distal. No adverse neurological complications were reported, although one patient experienced exacerbation of pre-existing gait ataxia. CONCLUSION: VOP/ZI stimulation is demonstrated here to be an effective and safe approach for the treatment of post-ABI tremor in the largest series published at the time of writing

High-contrast imaging constraints on gas giant planet formation - The Herbig Ae/Be star opportunity

Planet formation studies are often focused on solar-type stars, implicitly considering our Sun as reference point. This approach overlooks, however, that Herbig Ae/Be stars are in some sense much better targets to study planet formation processes empirically, with their disks generally being larger, brighter and simply easier to observe across a large wavelength range. In addition, massive gas giant planets have been found on wide orbits around early type stars, triggering the question if these objects did indeed form there and, if so, by what process. In the following I briefly review what we currently know about the occurrence rate of planets around intermediate mass stars, before discussing recent results from Herbig Ae/Be stars in the context of planet formation. The main emphasis is put on spatially resolved polarized light images of potentially planet forming disks and how these images - in combination with other data - can be used to empirically constrain (parts of) the planet formation process. Of particular interest are two objects, HD100546 and HD169142, where, in addition to intriguing morphological structures in the disks, direct observational evidence for (very) young planets has been reported. I conclude with an outlook, what further progress we can expect in the very near future with the next generation of high-contrast imagers at 8-m class telescopes and their synergies with ALMA.Comment: Accepted by Astrophysics and Space Science as invited short review in special issue about Herbig Ae/Be stars; 12 pages incl. 5 figures, 2 tables and reference

Surprise disrupts cognition via a fronto-basal ganglia suppressive mechanism

Surprising events markedly affect behaviour and cognition, yet the underlying mechanism is unclear. Surprise recruits a brain mechanism that globally suppresses motor activity, ostensibly via the subthalamic nucleus (STN) of the basal ganglia. Here, we tested whether this suppressive mechanism extends beyond skeletomotor suppression and also affects cognition (here, verbal working memory, WM). We recorded scalp-EEG (electrophysiology) in healthy participants and STN local field potentials in Parkinson's patients during a task in which surprise disrupted WM. For scalp-EEG, surprising events engage the same independent neural signal component that indexes action stopping in a stop-signal task. Importantly, the degree of this recruitment mediates surprise-related WM decrements. Intracranially, STN activity is also increased post surprise, especially when WM is interrupted. These results suggest that surprise interrupts cognition via the same fronto-basal ganglia mechanism that interrupts action. This motivates a new neural theory of how cognition is interrupted, and how distraction arises after surprising events

Particle Shape Characterisation and Classification using Automated Microscopy and Shape Descriptors in Batch Manufacture of Particulate Solids

It is known that size alone, as often defined as the volume equivalent diameter, is not sufficient for characterizing many particulate products. The shape of crystalline products can be as important as size in many applications. Traditionally particulate shape is often defined by some simple descriptors such as the maximum length and aspect ratio. Although these descriptors are intuitive, they result in loss of some information of the original shape. This paper presents a method to use principal component analysis (PCA) to derive simple latent shape descriptors from microscope images of particulate products made in batch processes, and the use of the descriptors for identification of batch to batch variations. Data from batch runs of both a laboratory crystalliser and an industrial crystallisation reactor are analysed using the approach. Qualitative and quantitative comparison with the use of traditional shape descriptors that have physical meanings and Fourier shape descriptors is also made