Assessment of the molecular structure of natrodufrénite – NaFe2+Fe3+5(PO4)4(OH)6•2(H2O), a secondary pegmatite phosphate mineral from Minas Gerais, Brazil

The mineral natrodufrénite a secondary pegmatite phosphate mineral from Minas Gerais, Brazil, has been studied by a combination of scanning electron microscopy and vibrational spectroscopic techniques. Electron probe analysis shows the formula of the studied mineral as (Na0.88Ca0.12)∑1.00(Mn0.11Mg0.08Ca0.04Zr0.01Cu0.01)∑0.97(Al0.02)∑4.91(PO4)3.96(OH6.15F0.07)6.22⋅2.05(H2O). Raman spectroscopy identifies an intense peak at 1003 cm−1 assigned to the ν1 symmetric stretching mode. Raman bands are observed at 1059 and 1118 cm−1 and are attributed to the ν3 antisymmetric stretching vibrations. A comparison is made with the spectral data of other hydrate hydroxy phosphate minerals including cyrilovite and wardite. Raman bands at 560, 582, 619 and 668 cm−1 are assigned to the ν4 bending modes and Raman bands at 425, 444, 477 and 507 cm−1 are due to the ν2 bending modes. Raman bands in the 2600–3800 cm−1 spectral range are attributed to water and OH stretching vibrations. Vibrational spectroscopy enables aspects of the molecular structure of natrodufrénite to be assessed.

Population structure and patterns of genetic variation in a pearl oyster (Pinctada radiata) native to the Arabian Gulf

The study assessed natural levels and patterns of genetic variation in Arabian Gulf populations of a native pearl oyster to define wild population structure considering potential intrinsic and extrinsic factors that could influence any wild structure detected. The study was also the first attempt to develop microsatellite markers and to generate a genome survey sequence (GSS) dataset for the target species using next generation sequencing technology. The partial genome dataset generated has potential biotechnological applications and for pearl oyster farming in the future.

The Chinese state enterprise sector: Labour market reform and the impact on male–female wage structure

The paper examines the wage structure in the Chinese state enterprise sector between 1981 and 1987. This period is of particular interest given the introduction of major labour market reforms in China during the early 1980s. In essence the reforms represented a movement away from administratively determined prices towards a market–oriented system combined with a relatively flexible system of labour allocation. The Juhn, Murphy and Pierce (1991) decomposition is employed to shed light on the role of changing labour market institutions over the period.

Vibrational spectroscopic characterization of the phosphate mineral barbosalite Fe2+Fe3+2(PO4)2(OH)2 : implications for the molecular structure

Natural single-crystal specimens of barbosalite from Brazil, with general formula Fe2+Fe3+ 2 (PO4)2(OH)2 were investigated by Raman and infrared spectroscopy. The mineral occurs as secondary products in granitic pegmatites. The Raman spectrum of barbosalite is characterized by bands at 1020, 1033 and 1044 cm−1 cm−1, assigned to ν1 symmetric stretching mode of the HOPO3- 3 and PO3- 4 units. Raman bands at around 1067, 1083 and 1138 cm−1 are attributed to both the HOP and PO antisymmetric stretching vibrations. The set of Raman bands observed at 575, 589 and 606 cm−1 are assigned to the ν4 out of plane bending modes of the PO4 and H2PO4 units. Raman bands at 439, 461, 475 and 503 cm−1 are attributed to the ν2 PO4 and H2PO4 bending modes. Strong Raman bands observed at 312, 346 cm−1 with shoulder bands at 361, 381 and 398 cm−1 are assigned to FeO stretching vibrations. No bands which are attributable to water vibrations were found. Vibrational spectroscopy enables aspects of the molecular structure of barbosalite to be assessed.

The molecular structure of the borate mineral inderite Mg(H4B3O7)(OH)⋅5H2O – A vibrational spectroscopic study

We have undertaken a study of the mineral inderite Mg(H4B3O7)(OH)⋅5H2O a hydrated hydroxy borate mineral of magnesium using scanning electron microscopy, thermogravimetry and vibrational spectroscopic techniques. The structure consists of [B3O3(OH)5]2-[B3O3(OH)5]2- soroborate groups and Mg(OH)2(H2O)4 octahedra interconnected into discrete molecules by the sharing of two OH groups. Thermogravimetry shows a mass loss of 47.2% at 137.5 °C, proving the mineral is thermally unstable. Raman bands at 954, 1047 and 1116 cm−1 are assigned to the trigonal symmetric stretching mode. The two bands at 880 and 916 cm−1 are attributed to the symmetric stretching mode of the tetrahedral boron. Both the Raman and infrared spectra of inderite show complexity. Raman bands are observed at 3052, 3233, 3330, 3392 attributed to water stretching vibrations and 3459 cm−1 with sharper bands at 3459, 3530 and 3562 cm−1 assigned to OH stretching vibrations. Vibrational spectroscopy is used to assess the molecular structure of inderite.

Confirmation of the assignment of vibrations of goethite: An ATR and IES study of goethite structure

Transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM/EDS) and X-ray diffraction (XRD) were used to characterize the morphology of synthetic goethite. The behavior of the hydroxyl/water molecular units of goethite and its thermally treated products were characterized using Fourier transform-infrared emission spectroscopy (FT-IES) and attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy. The results showed that all the expected vibrational bands between 4000 and 650 cm−1 including the resolved bands (3800–2200 cm−1) were confirmed. A band attributed to a new type of hydroxyl unit was found at 3708 cm−1 and assigned to the FeO–H stretching vibration without hydrogen bonding. This hydroxyl unit was retained up to the thermal treatment temperature of 500 °C. On the whole, seven kinds of hydroxyl units, involving three surface hydroxyls, a bulk hydroxyl, a FeO–H without hydrogen bonding, a nonstoichiometric hydroxyl and a reversed hydroxyl were observed, and three kinds of adsorbed water were found in/on goethite.

A population genomics overview of the neuronal nitric oxide synthase (nNOS) gene and its relationship to migraine susceptibility

The ubiquitous chemical messenger molecule nitric oxide (NO) has been implicated in a diverse range of biological activities including neurotransmission, smooth muscle motility and mediation of nociception. Endogenous synthesis of NO by the neuronal isoform of the nitric oxide synthase gene family has an essential role within the central and peripheral nervous systems in addition to the autonomic innervation of cerebral blood vessels. To investigate the potential role of NO and more specifically the neuronal nitric oxide synthase (nNOS) gene in migraine susceptibility, we investigated two microsatellite repeat variants residing within the 5′ and 3′ regions of the nNOS gene. Population genomic evaluation of the two nNOS repeat variants indicated significant linkage disequilibrium between the two loci. Z-DNA conformational sequence structures within the 5′ region of the nNOS gene have the potential to enhance or repress gene promoter activity. We suggest that genetic analysis of this 5′ repeat variant is the more functional variant expressing gene wide information that could affect endogenous NO synthesis and potentially result in diseased states. However, no association with migraine (with or without aura) was seen in our extensive case-control cohort (n = 579 affected with matched controls), when both the 5′ and 3′ genetic variants were investigated.

Aligned poly(L-lactic-co-ε-caprolactone) electrospun microfibers and knitted structure: a novel composite scaffold for ligament tissue engineering

We developed a novel technique involving knitting and electrospinning to fabricate a composite scaffold for ligament tissue engineering. Knitted structures were coated with poly(L-lactic-co-e-caprolactone) (PLCL) and then placed onto a rotating cylinder and a PLCL solution was electrospun onto the structure. Highly aligned 2-μm-diameter microfibers covered the space between the stitches and adhered to the knitted scaffolds. The stress–strain tensile curves exhibited an initial toe region similar to the tensile behavior of ligaments. Composite scaffolds had an elastic modulus (150 ± 14 MPa) similar to the modulus of human ligaments. Biological evaluation showed that cells proliferated on the composite scaffolds and they spontaneously orientated along the direction of microfiber alignment. The microfiber architecture also induced a high level of extracellular matrix secretion, which was characterized by immunostaining. We found that cells produced collagen type I and type III, two main components found in ligaments. After 14 days of culture, collagen type III started to form a fibrous network. We fabricated a composite scaffold having the mechanical properties of the knitted structure and the morphological properties of the aligned microfibers. It is difficult to seed a highly macroporous structure with cells, however the technique we developed enabled an easy cell seeding due to presence of the microfiber layer. Therefore, these scaffolds presented attractive properties for a future use in bioreactors for ligament tissue engineering.

Fluid-structure interaction analysis of full scale vehicle-barrier impact using coupled SPH-FEA

Portable water-filled barriers (PWFB) are roadside structures used to separate moving traffic from work-zones. Numerical PWFB modelling is preferred in the design stages prior to actual testing. This paper aims to study the fluid-structure interaction of PWFB under vehicular impact using several methods. The strategy to treat water as non-structural mass was proposed and the errors were investigated. It was found that water can be treated with the FEA-NSM model for velocities higher than 80kmh-1. However, full SPH/FEA model is still the best treatment for water and necessary for lower impact velocities. The findings in this paper can be used as guidelines for modelling and designing PWFB.

Validation of a new tool to measure responsiveness and structure in the feeding context : the Authoritative Feeding Practices Questionnaire

How mothers interact with their toddlers around food lays the foundations for healthy eating and healthy weight gain in later life. This research involving 467 Australian first-time mothers of 2-year-old children resulted in the development of a new self-report tool, the Authoritative Feeding Practices Questionnaire, assessing maternal responsive feeding and mealtime structure. Secondary analysis of the NOURISH randomised controlled trial included theory-driven item selection, confirmatory factor analysis, evaluation of psychometric properties and construct validation. The result is a brief, reliable and valid new tool for evaluating the maternal feeding practices that support children to become healthy, independent eaters.

Neurons Activated During Fear Memory Consolidation and Reconsolidation are Mapped to a Common and New Topography in the Lateral Amygdala

A key question in neuroscience is how memory is selectively allocated to neural networks in the brain. This question remains a significant research challenge, in both rodent models and humans alike, because of the inherent difficulty in tracking and deciphering large, highly dimensional neuronal ensembles that support memory (i.e., the engram). In a previous study we showed that consolidation of a new fear memory is allocated to a common topography of amygdala neurons. When a consolidated memory is retrieved, it may enter a labile state, requiring reconsolidation for it to persist. What is not known is whether the original spatial allocation of a consolidated memory changes during reconsolidation. Knowledge about the spatial allocation of a memory, during consolidation and reconsolidation, provides fundamental insight into its core physical structure (i.e., the engram). Using design-based stereology, we operationally define reconsolidation by showing a nearly identical quantity of neurons in the dorsolateral amygdala (LAd) that expressed a plasticity-related protein, phosphorylated mitogen-activated protein kinase, following both memory acquisition and retrieval. Next, we confirm that Pavlovian fear conditioning recruits a stable, topographically organized population of activated neurons in the LAd. When the stored fear memory was briefly reactivated in the presence of the relevant conditioned stimulus, a similar topography of activated neurons was uncovered. In addition, we found evidence for activated neurons allocated to new regions of the LAd. These findings provide the first insight into the spatial allocation of a fear engram in the LAd, during its consolidation and reconsolidation phase.

Structure-preserving Runge-Kutta methods for stochastic Hamiltonian equations with additive noise

There has been considerable recent work on the development of energy conserving one-step methods that are not symplectic. Here we extend these ideas to stochastic Hamiltonian problems with additive noise and show that there are classes of Runge-Kutta methods that are very effective in preserving the expectation of the Hamiltonian, but care has to be taken in how the Wiener increments are sampled at each timestep. Some numerical simulations illustrate the performance of these methods.

Differential entrainment of neuroelectric delta oscillations in developmental dyslexia

Oscillatory entrainment to the speech signal is important for language processing, but has not yet been studied in developmental disorders of language. Developmental dyslexia, a difficulty in acquiring efficient reading skills linked to difficulties with phonology (the sound structure of language), has been associated with behavioural entrainment deficits. It has been proposed that the phonological ‘deficit’ that characterises dyslexia across languages is related to impaired auditory entrainment to speech at lower frequencies via neuroelectric oscillations (<10 Hz, ‘temporal sampling theory’). Impaired entrainment to temporal modulations at lower frequencies would affect the recovery of the prosodic and syllabic structure of speech. Here we investigated event-related oscillatory EEG activity and contingent negative variation (CNV) to auditory rhythmic tone streams delivered at frequencies within the delta band (2 Hz, 1.5 Hz), relevant to sampling stressed syllables in speech. Given prior behavioural entrainment findings at these rates, we predicted functionally atypical entrainment of delta oscillations in dyslexia. Participants performed a rhythmic expectancy task, detecting occasional white noise targets interspersed with tones occurring regularly at rates of 2 Hz or 1.5 Hz. Both groups showed significant entrainment of delta oscillations to the rhythmic stimulus stream, however the strength of inter-trial delta phase coherence (ITC, ‘phase locking’) and the CNV were both significantly weaker in dyslexics, suggestive of weaker entrainment and less preparatory brain activity. Both ITC strength and CNV amplitude were significantly related to individual differences in language processing and reading. Additionally, the instantaneous phase of prestimulus delta oscillation predicted behavioural responding (response time) for control participants only.

The effect of varied test instructions on neuropsychological performance following mild traumatic brain injury : an investigation of ‘diagnosis threat’

Diagnosis threat is a psychosocial factor that has been proposed to contribute to poor outcomes following mild traumatic brain injury (mTBI). This threat is thought to impair the cognitive test performance of individuals with mTBI because of negative injury stereotypes. University students (N= 45, 62.2% female) with a history of mTBI were randomly allocated to a diagnosis threat (DT, n=15), reduced threat (DT-reduced, n=15) or neutral (n=15) group. The reduced threat condition invoked a positive stereotype (i.e., that people with mTBI can perform well on cognitive tests). All participants were given neutral instructions before they completed baseline tests of: a) objective cognitive function across a number of domains; b) psychological symptoms; and, c) PCS symptoms, including self-reported cognitive and emotional difficulties. Participants then received either neutral, DT or DT-reduced instructions, before repeating the tests. Results were analyzed using separate mixed model ANOVAs; one for each dependent measure. The only significant result was for the 2 X 3 ANOVA on an objective test of attention/working memory, Digit Span, p<.05, such that the DT-reduced group performed better than the other groups, which were not different from each other. Although not consistent with predictions or earlier DT studies, the absence of group differences on most tests fits with several recent DT findings. The results of this study suggest that it is timely to reconsider the role of DT as a unique contributor to poor mTBI outcome.

A multilevel model of work-life : examining the impact of group structure and relational job design

One in five Australian workers believes that work doesn’t fit well with their family and social commitments. Concurrently, organisations are recognising that to stay competitive they need policies and practices that support the multiple aspects of employees’ lives. Many employees work in group environments yet there is currently little group level work-life balance research. This paper proposes a new theoretical framework developed to understand the design of work groups to better facilitate work-life balance. This new framework focuses on task and relational job designs, group structures and processes and workplace culture.