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Despite being identified as a pervasive emotion in the modern workplace (Pfeffer & Sutton, 2000), fear oddly has not received a corresponding amount of attention among management researchers. In fact, Kish-Gephart, Detert, Treviño, and Edmondson (2009, p. 163) observe that we still have much to learn about the nature of fear in workplace settings, including “what it is, how and why it is experienced, and to what effects.” Bennis (1966) notes further that fear has always been a part of the work environment (see also Connelly & Turner, 2018), but it remains an especially important issue in today’s workplaces because of the effects of rapid and ongoing organizational change, which are often linked to uncertain outcomes (Bordia, Hobman, Jones, Gallois, & Callan, 2004; Tiedens & Linton, 2001). Our aim in this chapter is to provide an overview of fear (arising from uncertainty) as a discrete emotion, to identify stimuli that may trigger fear at work, and to identify the potential positive and negative outcomes that can be linked to employees’ fear. We also outline potential pathways for future research on fear of uncertainty in the workplace.
Early life stress (ELS) is a risk factor for the development of depression in adolescence; the mediating neurobiological mechanisms, however, are unknown. In this study, we examined in early pubertal youth the associations among ELS, cortisol stress responsivity, and white matter microstructure of the uncinate fasciculus and the fornix, two key frontolimbic tracts; we also tested whether and how these variables predicted depressive symptoms in later puberty. A total of 208 participants (117 females; M age = 11.37 years; M Tanner stage = 2.03) provided data across two or more assessment modalities: ELS; salivary cortisol levels during a psychosocial stress task; diffusion magnetic resonance imaging; and depressive symptoms. In early puberty there were significant associations between higher ELS and decreased cortisol production, and between decreased cortisol production and increased fractional anisotropy in the uncinate fasciculus. Further, increased fractional anisotropy in the uncinate fasciculus predicted higher depressive symptoms in later puberty, above and beyond earlier symptoms. In post hoc analyses, we found that sex moderated several additional associations. We discuss these findings within a broader conceptual model linking ELS, emotion dysregulation, and depression across the transition through puberty, and contend that brain circuits implicated in the control of hypothalamic–pituitary–adrenal axis function should be a focus of continued research.
This paper considers the manner in which turbulent premixed flames respond to a superposition of turbulent and narrowband disturbances. This is an important fundamental problem that arises in most combustion applications, as turbulent flames exist in hydrodynamically unstable flow fields and/or in confined systems with narrowband acoustic waves. This paper presents the first measurements of the sensitivity of the turbulent displacement speed to harmonically oscillating flame wrinkles. The flame is attached to a transversely oscillating, heated wire, resulting in the introduction of coherent, convecting wrinkles on the flame. The approach flow turbulence is varied systematically using a variable turbulence generator, enabling quantification of the effect of turbulent flow disturbances on the harmonic wrinkles. Mie scattering measurements are used to quantify the flame edge dynamics, while high speed particle image velocimetry is used to measure the flow field characteristics. By ensemble averaging the results, the ensemble-averaged flame edge and flow characteristics are recovered. For low turbulence intensities, sharp cusps are present in the negative curvature regions of the ensemble-averaged flame position, similar to laminar flames. These cusps are smoothed out at high turbulence intensities. The coherent, ensemble-averaged flame wrinkle amplitude decays with increasing turbulence intensity and with downstream distance. In addition, the ensemble-averaged turbulent flame speed is modulated in space and time. The most significant result of these measurements is the clear demonstration of the correlation between the ensemble-averaged turbulent flame speed and ensemble-averaged flame curvature, with the phase-dependent flame speed increasing in regions of negative curvature. These results have important implications on turbulent combustion physics and modelling, since quasi-coherent velocity disturbances are nearly ubiquitous in shear driven, high turbulent flows and/or confined systems with acoustic feedback. Specifically, these data clearly show that nonlinear interactions occur between the multi-scale turbulent disturbances and the more narrowband disturbances associated with coherent structures. In other words, conceptual models of the controlling physics in combustors with shear driven turbulence must account for the fundamentally different effects of spectrally distributed turbulent disturbances and more narrowband, quasi-coherent disturbances.
Early life stress (ELS) is a significant risk factor for the emergence of internalizing problems in adolescence. Beginning in adolescence, females are twice as likely as males to experience internalizing disorders. The present study was designed to examine sex differences in the association between ELS and internalizing problems in early pubertal adolescents, and whether and how corticolimbic function and connectivity may underlie these associations. Fifty-nine early pubertal males and 78 early pubertal females, ages 9–13 years (all Tanner Stage 3 or below) underwent functional magnetic resonance imaging as they performed an emotion label task that robustly interrogates corticolimbic function. Participants were also interviewed about their experience of ELS. Females exhibited a positive association between ELS and internalizing problems, whereas males exhibited no such association. Whole-brain and amygdala region of interest analyses indicated that whereas females exhibited a positive association between ELS and the ventrolateral prefrontal cortex during implicit emotion regulation, males showed no such association. Activation in these regions was positively associated with internalizing problems in females but not males; however, activation in these regions did not mediate the association between ELS and internalizing problems. Finally, both boys and girls exhibited an association between ELS and increased negative connectivity between the right ventrolateral prefrontal cortex and bilateral amygdala. Using a carefully characterized sample of early pubertal adolescents, the current study highlights important sex differences in the development of corticolimbic circuitry during a critical period of brain development. These sex differences may play a significant role in subsequent risk for internalizing problems.
Plasmodium knowlesi has risen in importance as a zoonotic parasite that has been causing regular episodes of malaria throughout South East Asia. The P. knowlesi genome sequence generated in 2008 highlighted and confirmed many similarities and differences in Plasmodium species, including a global view of several multigene families, such as the large SICAvar multigene family encoding the variant antigens known as the schizont-infected cell agglutination proteins. However, repetitive DNA sequences are the bane of any genome project, and this and other Plasmodium genome projects have not been immune to the gaps, rearrangements and other pitfalls created by these genomic features. Today, long-read PacBio and chromatin conformation technologies are overcoming such obstacles. Here, based on the use of these technologies, we present a highly refined de novo P. knowlesi genome sequence of the Pk1(A+) clone. This sequence and annotation, referred to as the ‘MaHPIC Pk genome sequence’, includes manual annotation of the SICAvar gene family with 136 full-length members categorized as type I or II. This sequence provides a framework that will permit a better understanding of the SICAvar repertoire, selective pressures acting on this gene family and mechanisms of antigenic variation in this species and other pathogens.
Conjugated polymers have been proposed as promising materials for scaffolds in tissue engineering applications. However, the restricted processability and biodegradability of conjugated polymers limit their use for biomedical applications. Here we synthesized a block-co-polymer of aniline tetramer and PCL (AT–PCL), and processed it into fibrous non-woven scaffolds by electrospinning. We showed that fibronectin (Fn) adhesion was dependent on the AT–PCL oxidative state, with a reduced Fn unfolding length on doped membranes. Furthermore, we demonstrated the cytocompatibility and potential of these membranes to support the growth and osteogenic differentiation of MC3T3-E1 cells over 21 days.
We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.
Tuberous sclerosis complex (TSC) is associated with intellectual disability, but the risk pathways are poorly understood.
The Tuberous Sclerosis 2000 Study is a prospective longitudinal study of the natural history of TSC. One hundred and twenty-five UK children age 0–16 years with TSC and born between January 2001 and December 2006 were studied. Intelligence was assessed using standardized measures at ≥2 years of age. The age of onset of epilepsy, the type of seizure disorder, the frequency and duration of seizures, as well as the response to treatment was assessed at interview and by review of medical records. The severity of epilepsy in the early years was estimated using the E-Chess score. Genetic studies identified the mutations and the number of cortical tubers was determined from brain scans.
TSC2 mutations were associated with significantly higher cortical tuber count than TSC1 mutations. The extent of brain involvement, as indexed by cortical tuber count, was associated with an earlier age of onset and severity of epilepsy. In turn, the severity of epilepsy was strongly associated with the degree of intellectual impairment. Structural equation modelling supported a causal pathway from genetic abnormality to cortical tuber count to epilepsy severity to intellectual outcome. Infantile spasms and status epilepticus were important contributors to seizure severity.
The findings support the proposition that severe, early onset epilepsy may impair intellectual development in TSC and highlight the potential importance of early, prompt and effective treatment or prevention of epilepsy in tuberous sclerosis.
The introduction of the Manila clam into British coastal waters in the 1980s was contested by conservation agencies. While recognizing the value of the clam for aquaculture, the government decided that it posed no invasive risk, as British sea temperatures would prevent naturalization. This proved incorrect. Here we establish the pattern of introduction and spread of the species over the first 30 years of its presence in Britain. We report archival research on the sequence of licensed introductions and examine their relationship in time and space to the appearance of wild populations as revealed in the literature and by field surveys. By 2010 the species had naturalized in at least 11 estuaries in southern England. These included estuaries with no history of licensed introduction. In these cases activities such as storage of catch before market or deliberate unlicensed introduction represent the probable mechanisms of dispersal. In any event naturalization is not an inevitable consequence of introduction and the chances of establishment over the period in question were finely balanced. Consequently in Britain the species is not currently aggressively invasive and appears not to present significant risk to indigenous diversity or ecosystem function. However it is likely to gradually continue its spread should sea surface temperatures rise as predicted.
Aquifers of the Austral region are globally significant in terms of their biodiversity. They support a rich and unique fauna, specifically adapted to the harsh subterranean environment. In this chapter we review the nature and diversity of groundwater ecosystems across the Austral region. We consider first the global origins of the Australian groundwater fauna, and their distributions across Gondwana. As the Australian continent evolved, the western shield emerged from the sea during the Proterozoic, which has led to a distinct fauna in those ancient landscapes. In the ‘newer’ eastern Austral regions there has also emerged a rich groundwater fauna, and here we review the current knowledge of fauna in eastern Australia and New Zealand. Mining and agricultural development threaten groundwater ecosystems across the region, but perhaps the greatest threat is our current lack of knowledge of these unique and important ecosystems and their biota. New approaches for conservation planning provide hope for improved recognition and protection of groundwater ecosystems, but with relatively little surveying of groundwater fauna having been done across the region, much remains undiscovered.
Being the driest inhabited continent on Earth, the availability of water has always been a critical factor shaping the evolution and distribution of species across Australia. So too, the availability of water is critical to the survival and prosperity of human populations across the broader region, from small outback towns to major capital cities. As human pressures increase demand for water, groundwater is increasingly being used to meet water needs of households, industries and farms. Groundwater use accounts for around 20% of the total water used across Australia, it is more than 50% in New Zealand (Fenwick et al. 2004), and in many areas it is the only reliable water supply.
This paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.
Given the finite nature of global phosphorus (P) resources, there is an increasing concern about balancing agronomic and environmental impacts from P usage on dairy farms. Data from a 3-year (2009–2011) survey were used to assess farm-gate P balances and P use efficiency (PUE) on 21 intensive grass-based dairy farms operating under the good agricultural practice (GAP) regulations in Ireland. Mean stocking rate (SR) was 2·06 livestock units (LU)/ha, mean P surplus was 5·09 kg/ha, or 0·004 kg P/kg milk solids (MS), and mean PUE was 0·70. Phosphorus imports were dominated by inorganic fertilizer (7·61 kg P/ha) and feeds (7·62 kg P/ha), while exports were dominated by milk (6·66 kg P/ha) and livestock (5·10 kg P/ha). Comparison to similar studies carried out before the introduction of the GAP regulations in 2006 indicated that P surplus, both per ha and per kg MS, has significantly decreased (by 74 and 81%, respectively) and PUE increased (by 48%), mostly due to decreased inorganic fertilizer P import and improvements in P management. There has been a notable shift towards spring application of organic manures, indicating improved awareness of the fertilizer value of organic manures and good compliance with the GAP regulations regarding fertilizer application timing. These results suggested a positive impact of the GAP regulations on dairy farm P surplus and PUE, indicating an improvement in both environmental and economic sustainability of dairy production through improved resource use efficiencies. Such improvements will be necessary to achieve national targets of improved water quality and increased dairy production. Results suggest that optimizing fertilizer and feed P imports combined with improved on-farm P recycling are the most effective way to increase PUE. Equally, continued monitoring of soil test P (STP) and P management will be necessary to ensure that adequate soil P fertility is maintained. Mean P surplus was lower and PUE was much higher than the overall mean surplus (15·92 kg P/ha) and PUE (0·47) from three studies of continental and English dairy farms, largely due to the low import system that is more typical in Ireland, with seasonal milk production (compact spring calving), low use of imported feeds and high use of grazed grass.
There is increasing concern about balancing agronomic and environmental gains from nitrogen (N) usage on dairy farms. Data from a 3-year (2009–2011) survey were used to assess farm-gate N balances and N use efficiency (NUE) on 21 intensive grass-based dairy farms operating under the good agricultural practice (GAP) regulations in Ireland. Mean stocking rate (SR) was 2·06 livestock units (LU)/ha, mean N surplus was 175 kg/ha, or 0·28 kg N/kg milk solids (MS), and mean NUE was 0·23. Nitrogen inputs were dominated by inorganic fertilizer (186 kg N/ha) and concentrates (26·6 kg N/ha), whereas outputs were dominated by milk (40·2 kg N/ha) and livestock (12·8 kg N/ha). Comparison with similar studies carried out before the introduction of the GAP regulations in 2006 would suggest that N surplus, both per ha and per kg MS, have significantly decreased (by 40 and 32%, respectively) and NUE increased (by 27%), mostly due to decreased inorganic fertilizer N input and improvements in N management, with a notable shift towards spring application of organic manures, indicating improved awareness of the fertilizer value of organic manures and good compliance with the GAP regulations regarding fertilizer application timing. These results would suggest a positive impact of the GAP regulations on dairy farm N surplus and NUE, indicating an improvement in both environmental and economic sustainability of dairy production through improved resource-use efficiencies. Such improvements will be necessary to achieve national targets of improved water quality and increased efficiency/sustainability of the dairy industry. The weak impact of SR on N surplus found in the present study would suggest that, with good management, increased SR and milk output per ha may be achievable, while decreasing N surplus per ha. Mean N surplus was lower than the overall mean surplus (224 kg N/ha) from six studies of northern and continental European dairy farms, while mean NUE was similar, largely due to the low input/output system that is more typical in Ireland, with seasonal milk production (compact spring calving), low use of concentrates, imported feed and forages, high use of grazed grass and lower milk yields per ha.
We studied the effect of a cross-conjugated bridging group (χC) on charge-transfer in a push-pull chromophore system. The hyperpolarizability of such molecules was found to be comparable to that of a fully π-conjugated molecule (πC) with the same donor and acceptor. The cross-conjugated moiety was then applied as a pendant to a fully π-conjugated chromophore containing a tricyanopyrroline acceptor (TCP). The addition of a χC moiety did not alter the intrinsic hyperpolarizability and provides an avenue for extending and aiding πC systems. The molecules were examined by X-ray diffraction (XRD), hyper-Raleigh scattering (HRS) and UV-visible (UV-vis) spectroscopy. Experimental results were compared with the predictions of density functional theory (DFT). Cross-conjugated molecules have comparable β values, relative to πC molecules, due to reduced spatial overlap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Thus, the χC architecture could facilitate independent modification of donor and acceptor strengths while minimizing unfavorable effects on electronic transitions and dipole moments.
Two methods for the fabrication of flexible and stretchable photonic crystal slabs are demonstrated and compared. In both cases a periodically nanostructured polydimethylsiloxane (PDMS) membrane is used as substrate. The first method is based on oblique-angle vapor deposition of SiO as a high refractive index material onto the nanostructured membrane. The deposition is made at an angle of 45° to the surface. The grooves of the nanostructure are aligned such that shading effects cause an inhomogeneous layer thickness distribution on the surface. This supports controlled, periodic cracking of the high index layer upon stretching. In the second approach ZnO nanoparticles are spin-coated on the nanostructured PDMS membrane. Here, the membrane can be stretched and serves as a photonic crystal slab without the need of any further treatment. For both types of flexible photonic crystal slabs a shift of the guided mode resonances to longer wavelengths is observed upon stretching. For a 20% strain perpendicular to the grating grooves a resonance shift of more than 50 nm is obtained.
It is well known that exposure to ultraviolet (UV) light can result in various physical and psychological diseases. Therefore, there is a strong demand for a reliable sensor to monitor UV exposure levels in the physiologically relevant intensity ranges of mW/cm2. Here, we demonstrate a UV sensor based on a silica whispering gallery mode microresonator. This UV sensor works over physiologically relevant intensity ranges with linear performance both in the forward and backward operating directions, with very high signal-to-noise ratio that can be utilized in monitoring the UV exposure for various applications.
The use of organic nonlinear optical (ONLO) materials in electro-optic (EO) modulators requires that the active molecular components (chromophores) be acentrically oriented. The fundamental molecular constituents are in a condensed, glassy phase. Molecular orientation in such systems is typically achieved by applying a DC poling field to the glassy material. We are developing efficient coarse-grained classical Monte Carlo (MC) methods to simulate the order of such systems. The most challenging aspects of these simulations are convergence to an experimentally relevant equilibrium ensemble and verification of simulation accuracy. We use a variety of molecular descriptions and a variety of MC methods to achieve proper order in the shortest number of computational cycles possible. Herein, we illustrate a few examples of the types of calculations and compare with experimental results with representative amorphous organic materials, including electro-optic chromophores.