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Researchers increasingly rely on aggregations of radiocarbon dates from archaeological sites as proxies for past human populations. This approach has been critiqued on several grounds, including the assumptions that material is deposited, preserved, and sampled in proportion to past population size. However, various attempts to quantitatively assess the approach suggest there may be some validity in assuming date counts reflect relative population size. To add to this conversation, here we conduct a preliminary analysis coupling estimates of ethnographic population density with late Holocene radiocarbon dates across all counties in California. Results show that counts of late Holocene radiocarbon-dated archaeological sites increase significantly as a function of ethnographic population density. This trend is robust across varying sampling windows over the last 5000 BP. Though the majority of variation in dated-site counts remains unexplained by population density. Outliers reveal how departures from the central trend may be influenced by regional differences in research traditions, development-driven contract work, organic preservation, and landscape taphonomy. Overall, this exercise provides some support for the "dates-as-data" approach and offers insights into the conditions where the underlying assumptions may or may not hold. [ABSTRACT FROM AUTHOR]

The notion of 'place' has become a central concern in research on the populist radical right (PRR), but scholars seem to have different things in mind when talking about how geography affects individual political attitudes. In our paper, we therefore aim to structure the debate on the impact of place and to understand exactly how place affects PRR attitudes (nativism, right-wing authoritarianism, and populism). Conceptually, we identify four potentially relevant aspects of 'place' that underpin much of the current literature: place-related attitudes (localism and resentment), place-specific living conditions, socio-demographic composition, and characteristics unique to a particular place, i.e., its local history and culture. We also discuss how these aspects are related and how they may interact. Empirically, we assess the relative importance of these four aspects of place for PRR sentiment in Germany, a country that is particularly well suited to this type of analysis. Using fine-grained geocoded survey data collected prior to the 2017 election, we find that (1) there is considerable spatial variation and clustering in PRR attitudes, (2) a place's socio-demographic composition and (3) place resentment account for much of this, while (4) localism has weaker effects. We find (5) no relevant interaction between localism and place resentment, (6) no substantial evidence that mediation through place-related attitudes leads to an underestimation of the other aspects, and (7) no evidence for effects of the unique culture or history of the places we studied. Moreover, (8) location in the former GDR still has a substantial impact, whereas (9) other place-specific conditions (deprivation, demographic decline, migration, rurality) that could be addressed by policy interventions have no or rather weak effects. We conclude that PRR sentiment in 'places that don't matter' results also, though by no means exclusively, from a lack of recognition. [ABSTRACT FROM AUTHOR]

A fundamental open problem in the mechanics of granular media is the determination of the stress in the static state. It is known that the static stress depends strongly on how the grain assembly is created and the nature of confining boundaries. Non-trivial spatial variations have been observed even in simple geometries, posing long-standing challenges to continuum modelling. In this paper, we create gravity-deposited grain packings computationally and devise a method to visualise the paths of load transmission, which we call force lines. We show that the force lines reflect the flow during deposition, thereby encoding preparation history. We then show that the force lines coincide with ensemble averaged biased random walks in the particle contact network; this identification yields a closure relation for the stress, which together with the static momentum balances fully determines the stress field. The model makes accurate predictions for the stress in piles and silos, even for unusual deposition methods, thereby showing promise for more general scenarios. [ABSTRACT FROM AUTHOR]

Objective: To analyse the spatial variation and risk factors of the dual burden of childhood stunting and wasting in Myanmar. Design: Analysis was carried out on nationally representative data obtained from the Myanmar Demographic and Health Survey conducted during 2015–2016. Childhood stunting and wasting are used as proxies of chronic and acute childhood undernutrition. A child with standardised height-for-age Z score (HAZ) below –2 is categorised as stunted while that with a weight-for-height Z score (WHZ) below –2 as wasted. Setting: A nationally representative sample of households from the fifteen states and regions of Myanmar. Participants: Children under the age of five ($n$ 4162). Results: Overall marginal prevalence of childhood stunting and wasting was 28·9 % (95 % CI 27·5, 30·2) and 7·3 % (95 % CI 6·5, 8·0) while their concurrent prevalence was 1·6 % (95 % CI 1·2, 2·0). The study revealed mild positive association between stunting and wasting across Myanmar. Both stunting and wasting had significant spatial variation across the country with eastern regions having higher burden of stunting while southern regions having higher prevalence of wasting. Child age and maternal WHZ score had significant non-linear association with both stunting and wasting while child gender, ethnicity and household wealth quintile had significant association with stunting. Conclusion: The study provides data-driven evidence about the association between stunting and wasting and their spatial variation across Myanmar. The resulting insights can aid in the formulation and implementation of targeted, region-specific interventions towards improving the state of childhood undernutrition in Myanmar. [ABSTRACT FROM AUTHOR]

Air temperature inversions, a situation in which atmospheric temperature increases with height, are key components of the Arctic planetary boundary layer. The present study investigates the spatial and temporal variations of temperature inversions over different surface types (rock, gravel, snow, ice) along the Mittivakkat valley (southeast Greenland). For this purpose, 113 vertical profiles with high spatio-temporal resolution of air temperature and relative humidity were collected with unoccupied aerial vehicles (UAVs) during a 13-day field campaign in summer 2019. Air temperature inversions were present in 83% of the profiles, of which 24% were surface-based inversions and 76% were elevated inversions. The proglacial area covered with bare rock and gravel induces surface heating and convection during the day and, through interaction with local circulation patterns, leads to the frequent formation of elevated inversions. In contrast, the glacier surface itself acts as a persistent cooling surface and leads to the formation of surface-based inversions. A low-level fog layer that forms under the inversion layer may be causing non-linear vertical ablation gradients on Mittivakkat Gletsjer. Furthermore, we demonstrate that atmospheric measurements using UAVs can better capture small-scale processes than other products like radiosonde or modeled reanalysis data. [ABSTRACT FROM AUTHOR]

Bathymetry is an important factor affecting wave propagation in coastal environments but is often challenging to measure in practice. We propose a method for inferring coastal bathymetry from spatial variations in surface waves by combining a high-order spectral method for wave simulation and an adjoint-based variational data assimilation method. Recursion-formed adjoint equations are derived to obtain the sensitivity of the wave surface elevation to the underlying bottom topography to any desired order of nonlinear perturbation. We also develop a multiscale optimisation method to eliminate spurious high-wavenumber fluctuations in the reconstructed bathymetry data caused by sensitivity variations over the different length scales of surface waves. The proposed bottom detection method is validated with a realistic coastal wave environment involving complex two-dimensional bathymetry features, non-periodic incident waves and nonlinear broadband multidirectional waves. In numerical experiments at both laboratory and field scales, the bathymetry reconstructed from our method agrees well with the ground truth. We also show that our method is robust against imperfect surface wave data in the presence of limited sampling frequency and noise. [ABSTRACT FROM AUTHOR]

A mathematical model for the effect of the spatial variation of the local evaporative flux on the evaporation of and deposition from a thin pinned particle-laden sessile droplet is formulated and solved. We then analyse the behaviour for a one-parameter family of local evaporative fluxes with the free parameter $n \, (>-1)$ that exhibits qualitatively different behaviours mimicking those that can be obtained by, for example, surrounding the droplet with a bath of fluid or using a mask with one or more holes in it to achieve a desired pattern of evaporation enhancement and/or suppression. We show that when $-1 (including the special cases $n=-1/2$ of diffusion-limited evaporation into an unbounded atmosphere and $n=0$ of spatially uniform evaporation), all of the particles are eventually advected to the contact line, and so the final deposit is a ring deposit at the contact line, whereas when $n>1$ all of the particles are eventually advected to the centre of the droplet, and so the final deposit is at the centre of the droplet. In particular, the present work demonstrates that a singular (or even a non-zero) evaporative flux at the contact line is not an essential requirement for the formation of a ring deposit. In addition, we calculate the paths of the particles when diffusion is slower than both axial and radial advection, and show that in this regime all of the particles are captured by the descending free surface before eventually being deposited onto the substrate. [ABSTRACT FROM AUTHOR]

This study aims to examine the spatial evolution of the geometrical features of the turbulent/turbulent interface (TTI) in a cylinder wake. The wake is exposed to various turbulent backgrounds in which the turbulence intensity and the integral length scale are varied independently, and comparisons to a turbulent/non-turbulent interface (TNTI) are drawn. The turbulent wake was marked with a high Schmidt number ($Sc$) scalar, and a planar laser induced fluorescence experiment was carried out to capture the interface between the wake and the ambient flow from $x/d = 5$ to 40, where $x$ is the streamwise coordinate from the centre of the cylinder, and $d$ is the cylinder's diameter. It is found that the TTI generally spreads faster towards the ambient flow than the TNTI. A transition region of the interfaces' spreading is found at $x/d \approx 15$ , after which the interfaces propagate at a slower rate than previously (upstream), and the mean interface positions of both the TNTI and TTI scale with the local wake half-width. The locations of both the TNTI and TTI have non-Gaussian probability density functions (PDFs) in the near wake because of the influence of the large-scale coherent motions present within the flow. Further downstream, after the large-scale coherent motions have dissipated, the TNTI position PDF does become Gaussian. For the first time, we explore the spatial variation of the 'roughness' of the TTI, quantified via the fractal dimension, from near field to far field. The length scale in the background flow has a profound effect on the TTI fractal dimension in the near wake, whilst the turbulence intensity becomes important only for the fractal dimension farther downstream. [ABSTRACT FROM AUTHOR]

Supraglacial debris cover regulates the melt rates of many glaciers in mountainous regions around the world, thereby modifying the availability and quality of downstream water resources. However, the influence of supraglacial debris is often poorly represented within glaciological models, due to the absence of a technique to provide high-precision, spatially continuous measurements of debris thickness. Here, we use high-resolution UAV-derived thermal imagery, in conjunction with local meteorological data, visible UAV imagery and vertically profiled debris temperature time series, to model the spatially distributed debris thickness across a portion of Llaca Glacier in the Cordillera Blanca of Peru. Based on our results, we simulate daily sub-debris melt rates over a 3-month period during 2019. We demonstrate that, by effectively calibrating the radiometric thermal imagery and accounting for temporal and spatial variations in meteorological variables during UAV surveys, thermal UAV data can be used to more precisely represent the highly heterogeneous patterns of debris thickness and sub-debris melt on debris-covered glaciers. Additionally, our results indicate a mean sub-debris melt rate nearly three times greater than the mean melt rate simulated from satellite-derived debris thicknesses, emphasising the importance of acquiring further high-precision debris thickness data for the purposes of investigating glacier-scale melt processes, calibrating regional melt models and improving the accuracy of runoff predictions. [ABSTRACT FROM AUTHOR]

In many natural settings, spatial variations in a fluid's viscosity arise due to changes in its local physico-chemical environment. We consider the low-Reynolds-number dynamics of slender bodies in fluids with a linearly varying viscosity. Assuming the spatial change in viscosity to be small compared to the spatial deviation of the body but large relative to the body's aspect ratio, we derive the modifications to resistive-force theory in a fluid due to a constant viscosity gradient. At leading order in the body slenderness, the results are identical to the classical theory in a constant-viscosity fluid but with the viscosity taking everywhere its local, non-constant value. At next order in slenderness, non-local terms arise due to the non-zero viscosity gradient. We use our results to predict the motion of straight and toroidal filaments settling under the action of gravity. We show that viscosity gradients induce rigid-body rotation of the filaments at a rate proportional to the components of the gradients along the filaments. This result contrasts with constant-viscosity fluids where the filaments do not rotate. We demonstrate further that if the viscosity gradient acts in the direction opposite to the gravitational field, then the filaments rotate towards a stable orientation, whose value depends on the ratio between the viscosity gradients parallel and perpendicular to the gravitational field; otherwise, the filaments align in the direction of the gravitational field. Our work shows that viscosity gradients can exert new forces on slender bodies, which could, for example, be used to control their orientation and drift. [ABSTRACT FROM AUTHOR]

The systematic development of coarse-grained (CG) models via the Mori–Zwanzig projector operator formalism requires the explicit description of a deterministic drift term, a dissipative memory term and a random fluctuation term. The memory and fluctuating terms are related by the fluctuation–dissipation relation and are more challenging to sample and describe than the drift term due to complex dependence on space and time. This work proposes a rational basis for a Markovian data-driven approach to approximating the memory and fluctuating terms. We assumed a functional form for the memory kernel and under broad regularity hypothesis, we derived bounds for the error committed in replacing the original term with an approximation obtained by its asymptotic expansions. These error bounds depend on the characteristic time scale of the atomistic model, representing the decay of the autocorrelation function of the fluctuating force; and the characteristic time scale of the CG model, representing the decay of the autocorrelation function of the momenta of the beads. Using appropriate parameters to describe these time scales, we provide a quantitative meaning to the observation that the Markovian approximation improves as they separate. We then proceed to show how the leading-order term of such expansion can be identified with the Markovian approximation usually considered in the CG theory. We also show that, while the error of the approximation involving time can be controlled, the Markovian term usually considered in CG simulations may exhibit significant spatial variation. It follows that assuming a spatially constant memory term is an uncontrolled approximation which should be carefully checked. We complement our analysis with an application to the estimation of the memory in the CG model of a one-dimensional Lennard–Jones chain with different masses and interactions, showing that even for such a simple case, a non-negligible spatial dependence for the memory term exists. [ABSTRACT FROM AUTHOR]

Multiple micronutrient deficiencies are widespread in Ethiopia. However, the distribution of Se and Zn deficiency risks has previously shown evidence of spatially dependent variability, warranting the need to explore this aspect for wider micronutrients. Here, blood serum concentrations for Ca, Mg, Co, Cu and Mo were measured (n 3102) on samples from the Ethiopian National Micronutrient Survey. Geostatistical modelling was used to test spatial variation of these micronutrients for women of reproductive age, who represent the largest demographic group surveyed (n 1290). Median serum concentrations were 8·6 mg dl−1 for Ca, 1·9 mg dl−1 for Mg, 0·4 µg l−1 for Co, 98·8 µg dl−1 for Cu and 0·2 µg dl−1 for Mo. The prevalence of Ca, Mg and Co deficiency was 41·6 %, 29·2 % and 15·9 %, respectively; Cu and Mo deficiency prevalence was 7·6 % and 0·3 %, respectively. A higher prevalence of Ca, Cu and Mo deficiency was observed in north western, Co deficiency in central and Mg deficiency in north eastern parts of Ethiopia. Serum Ca, Mg and Mo concentrations show spatial dependencies up to 140–500 km; however, there was no evidence of spatial correlations for serum Co and Cu concentrations. These new data indicate the scale of multiple mineral micronutrient deficiency in Ethiopia and the geographical differences in the prevalence of deficiencies suggesting the need to consider targeted responses during the planning of nutrition intervention programmes. [ABSTRACT FROM AUTHOR]

The rate of star formation (SFR) is one of the important quantities that helps to study galaxies' evolutionary path. In fact, measuring the SFR during the life of the Universe shows us how galaxies have acquired their metallicity and star mass. In this regard, the galaxies of the Local Group give us a great opportunity to study the connection between different stellar populations and galaxy evolution. In this paper, we use the Long-Period variable stars to estimate the radial star formation in the disc of the M31 galaxy. These stars are powerful instruments to achieve this goal. They reach their peak luminosity and coldest state at the final point of their evolution. Also, there is a directly related between their mass and luminosity, so using stellar evolution theoretical models, we construct the mass function and hence the star formation history (SFH). In the disc of M31, we see an increase in the rate of star formation and a decrease in the age of stars in the outer parts. These results predict the inside-out growth well. [ABSTRACT FROM AUTHOR]

This article studies the persistent effects of past agrarian inequality on contemporary voting preferences. Although Western European countries became industrial (and later post-industrial) economies, the political effects of the agrarian cleavage are still visible in those countries in which the agrarian issue was dominant in the interwar period (the industrial laggards). Looking at the spatial variation in voting patterns in the fifteen elections held in Spain since 1977, we show through mediation analysis that areas with high historical agrarian inequality have higher levels of leftist vote. We examine two transmission channels: one economic (related to backwardness); the other political (related to family transmission of political allegiances). A survey analysis provides evidence in favour of family transmission. A brief exploration of other cases confirms the general argument: a similar effect is found in Italy (an industrial laggard), but not in England (an early industrializer). [ABSTRACT FROM AUTHOR]

We explore the two-dimensional flow past a cylinder undergoing forced transversal oscillations with the aim of elucidating the evolution of the topology of the wake under variation of the forcing amplitude at a Reynolds number of 100. In particular, we study the change from two single vortices (2S mode) to a pair and a single vortex (P + S mode) being shed per period. Matharu et al. (J. Fluid Mech., vol. 918, 2021, p. A21) showed that a dynamical symmetry-breaking pitchfork bifurcation plays a key role in this transition. We show that in addition to this bifurcation, a number of topological bifurcations in the vorticity field occur, both on the symmetric 2S branch and on the asymmetric P + S branch. The topological bifurcations are cusp bifurcations where an extremum of vorticity is created or destroyed. To describe the effect of the topological bifurcations we introduce an extended symbolic classification of the wake modes to account for the spatial variations of the vortex patterns that occur in the transition process.We identify four amplitude values that define critical stages in the transition, and provide a complete qualitative picture of the transition from 2S to P + S mode. We confirm the robustness of the observed transition process by simulations at Reynolds number 80. [ABSTRACT FROM AUTHOR]

This paper explores the screech closure mechanism for different axisymmetric modes in shock-containing jets. While many of the discontinuities in tonal frequency exhibited by screeching jets can be associated with a change in the azimuthal mode, there has to date been no satisfactory explanation for the existence of multiple axisymmetric modes at different frequencies. This paper provides just such an explanation. As shown in previous works, specific wavenumbers arise from the interaction of waves in the flow with the shocks. This provides new paths for driving upstream-travelling waves that can potentially close the resonance loop. Predictions using locally parallel and spatially periodic linear stability analyses and the wavenumber spectrum of the shock-cell structure suggest that the A1 mode resonance is closed by a wave generated when the Kelvin–Helmholtz mode interacts with the leading wavenumber of the shock-cell structure. The A2 mode is closed by a wave that arises owing to the interaction between the Kelvin–Helmholtz wave and a secondary wavenumber peak, which arises from the spatial variation of the shock-cell wavelength. The predictions are shown to closely match experimental data, and possible justifications for the dominance of each mode are provided based on the growth rates of the absolute instability. [ABSTRACT FROM AUTHOR]

This paper investigates German /l/-vocalization in the dialect region of South/Central Bavarian. In Austria, /l/-vocalization is said to be restricted to Central Bavarian, constituting the most salient dialect feature. However, its existence within the transition zone of South/Central Bavarian, including the urban and surrounding area of Graz, is often assumed. By analyzing natural speech data of different age groups from Greater Graz in a formal and an informal communication situation, we see that /l/-vocalization is already a well-established phenomenon, whereby the older age-group vocalizes considerably more often than the younger one. This suggests that /l/-vocalization serves as a sociolinguistic rather than a dialect marker indicating regional identity. [ABSTRACT FROM AUTHOR]

The c. 1.5–1.3 Ga Wilton package, the upper succession of the greater McArthur Basin, preserves detailed tectono-sedimentary evidence for the Mesoproterozoic evolution of the North Australian Craton (NAC). In addition, it is a valuable global sedimentary repository for the poorly explored Mesoproterozoic. New detrital zircon U–Pb age and Lu–Hf isotope data, collected from multiple, geographically separated, basins that make up the Wilton package, are compiled with previously published data to illuminate the basin evolution. The spatial and temporal variation in sedimentary provenance illustrates two major geographic changes that correspond to continent-scale tectonic convulsions of the NAC during the Mesoproterozoic. The first is shown by the influx of sediment sourced from east and southeast terranes. This is linked to rifting between Proterozoic Australia and Laurentia at c. 1.45 Ga, resulting in the uplift of the eastern margin of the NAC–SAC (South Australian Craton). The second basin geographic change is illustrated by a flux of southerly-sourced detritus that is interpreted to be tectonically driven by the uplift of the southern NAC, during the subduction/closure of the Mirning Ocean at c. 1.32 Ga. Spatially, sediment in the Wilton package is separated into two depositional systems: sedimentary rocks within the Birrindudu Basin, the western component of the Wilton package, have different detrital signatures relative to other Wilton package successions found east of the Daly Waters Fault Zone, in the Beetaloo Sub-basin, the McArthur Basin and the South Nicholson Basin. The Daly Waters Fault Zone is interpreted as an ancient bathymetric high, blocking sediment transport. Although they differ in sources, rocks in both the Birrindudu Basin and the eastern Wilton package record coeval shifts of basin provenance to southern sources. The coherent evolution of basin provenance indicates a consistent tectono-sedimentation history, and links the Birrindudu Basin and the other Wilton successions in a tectonic framework. [ABSTRACT FROM AUTHOR]

This paper examines a new interpretation for spatial mutual information based on the mutual information between an attribute value and a spatial random variable. This new interpretation permits the measurement of variations in spatial mutual information over the domain, not only answering the question of whether a spatial dependency exists and the strength of that dependency, but also allowing the identification of where such dependencies exist. Using simulated and real vessel reporting data, the properties of this new interpretation of spatial mutual information are explored. The utility of the technique in detecting spatial boundaries between regions of data having different statistical properties is examined. The technique is shown to successfully identify vessel traffic boundaries, crossing points between traffic lanes, and transitions between regions having differing vessel movement patterns. [ABSTRACT FROM AUTHOR]

Long-term exploration of the Groningen gas field in the Netherlands led to induced seismicity. Over the past nine years, an increasingly sophisticated Ground Motion Model (GMM) has been developed to assess the site response and the related seismic hazard. The GMM output strongly depends on the shear-wave velocity (V S ), among other input parameters. To date, V S model data from soil profiles (Kruiver et al., Bulletin of Earthquake Engineering, 15(9): 3555–3580, 2017; Netherlands Journal of Geosciences, 96(5): s215–s233, 2017) have been used in the GMM. Recently, new V S profiles above the Groningen gas field were constructed using ambient noise surface wave tomography. These so-called field V S data, even though spatially limited, provide an independent source of V S to check whether the level of spatial variability in the GMM is sufficient. Here, we compared amplification factors (AF) for two sites (Borgsweer and Loppersum) calculated with the model V S and the field V S (Chmiel et al., Geophysical Journal International, 218(3), 1781–1795, 2019 and new data). Our AF results over periods relevant for seismic risk (0.01–1.0 s) show that model and field V S profiles agree within the uncertainty range generally accepted in geo-engineering. In addition, we compared modelled spectral accelerations using either field V S or model V S in Loppersum to the recordings of an earthquake that occurred during the monitoring period (ML 3.4 Zeerijp on 8 January 2018). The modelled spectral accelerations at the surface for both field V S and model V S are coherent with the earthquake data for the resonance periods representative of most buildings in Groningen (T = 0.2 and 0.3 s). These results confirm that the currently used V S model in the GMM captures spatial variability in the site response and represents reliable input for the site response calculations. [ABSTRACT FROM AUTHOR]

Summary: Grain sorghum [Sorghum bicolor (L.) Moench] is the major cereal crop used as staple crop in the arid and semi-arid regions of Ethiopia. Low sorghum yields are attributed to soil, climate and topographic factors. We investigated sorghum yield response to factorial combination of nitrogen and phosphorous (NP) as well as potassium (K), sulphur (S) and zinc (Zn), and how the position of farmers' fields belonging to different landscape positions (i.e., upslope, mid-slope, and foot slope) could explain fertilizer response and yield variability. The analysis in this study made use of dataset from two sets of on-farm experiments where trials were set at two farmers' fields for NPKS and three farmers' fields for NPZn experiments in each landscape position. The experiments were implemented at two sorghum-growing locations (i.e., Hayk and Sirinka) in parts of the north-eastern Amhara region in Ethiopia. Sorghum yield response to fertilizer application was strongly linked to the spatial variation along landscape positions and varied over locations. Fertilizer response was significantly higher at foot slopes compared to mid-slopes and upslope positions, where fields at foot slopes exhibited relatively homogeneous responses. Application of combined nitrogen (N) and phosphorus (P) fertilizers, landscape position and the interaction of fertilizer application and landscape positions strongly affected sorghum yield. There was a linear and significant increase in sorghum yield with the increase in the NP rates. The combined application of NP with different levels of KS as well as NP with Zn fertilizer rates did not result in significant yield difference. The results indicated that local factors were much more influential when accounting for the heterogeneity in sorghum yield response to fertilizer. This further acknowledges the importance of a landscape-based fertilizer management approach to respond yield potential variability related with the farmers' fields and landscape environment. Further investigation is needed to develop homogeneous fertilizer response units based on spatial variability of soil and topographic attributes along the landscape. [ABSTRACT FROM AUTHOR]

Objective: High salt intake is one of the leading diet-related risk factors for several non-communicable diseases. We aimed to estimate the prevalence of high salt intake in Iran. Design: A modelling study by the small area estimation method, based on a nationwide cross-sectional survey, Iran STEPwise approach to risk factor Surveillance (STEPS) 2016. The modelling estimated the prevalence of high salt intake, defined as a daily salt intake ≥ 5 g in all districts of Iran based on data from available districts. The modelling results were provided in different geographical and socio-economic scales to make the comparison possible across the country. Setting: 429 districts of all provinces of Iran, 2016. Participants: 18 635 salt intake measurements from individuals 25 years old and above who participated in the Iran STEPS 2016 survey. Results: All districts in Iran had a high prevalence of high salt intake. The estimated prevalence of high salt intake among females of all districts ranged between 72·68 % (95 % UI 58·48, 84·81) and 95·04 % (95 % UI 87·10, 100). Estimated prevalence for males ranged between 88·44 % (95 % UI 80·29, 96·15) and 98·64 % (95 % UI 94·97, 100). In all categorisations, males had a significantly higher prevalence of high salt intake. Among females, the population with the lower economic status had a higher salt consumption than the participants with higher economic status by investigating the concentration index. Conclusions: Findings of this study highlight the high salt intake as a prominent risk factor in all Iran regions, despite some variations in different scales. More suitable population-wide policies are warranted to handle this public health issue in Iran. [ABSTRACT FROM AUTHOR]

The East Asian winter monsoon (EAWM) is one of the most dynamic components of the global climate system. Although poorly understood, knowledge of long-term spatial differences in EAWM variability during the glacial–interglacial cycles is important for understanding the dynamic processes of the EAWM. We reconstructed the spatiotemporal characteristics of the EAWM since the last glacial maximum (LGM) using a comparison of proxy records and long-term transient simulations. A loess grain-size record from northern China (a sensitive EAWM proxy) and the sea surface temperature gradient of an EAWM index in sediments of the southern South China Sea were compared. The data–model comparison indicates pronounced spatial differences in EAWM evolution, with a weakened EAWM since the LGM in northern China but a strengthened EAWM from the LGM to the early Holocene, followed by a weakening trend, in southern China. The model results suggest that variations in the EAWM in northern China were driven mainly by changes in atmospheric carbon dioxide (CO2) concentration and Northern Hemisphere ice sheets, whereas orbital insolation and ice sheets were important drivers in southern China. We propose that the relative importance of insolation, ice sheets, and atmospheric CO2 for EAWM evolution varied spatially within East Asia. [ABSTRACT FROM AUTHOR]

Stable isotope ratios (δ18O and δD) in Antarctic snow and ice are basic proxy indices of climate in ice core studies. The relation between the ratios has important indicative significance for moisture sources. In general, the fractionation characteristics of the two isotopes vary with different meteorological and topographical conditions. This paper presents the spatial and temporal distribution of meteoric water line (MWL) slopes along a traverse from the Zhongshan Station (ZSS) to Dome A in East Antarctica. It is found that the slopes decrease with the increasing distance inland from the coast and the lowest slope occurred at Dome A, where the long-range transported moisture dominates and clear sky snowing have an influence. The slopes in different layers of the snowpack showed a decreasing trend with depth and this is attributed to the fractionation during the interstitial sublimation and re-condensation processes of the water vapor. Frost flower development on the interior plateau surface can greatly alter the depth evolution of the MWL slope. The coastal snow pits also go through the post-depositional smoothing effect, but their influences are not so significant as the inland regions. [ABSTRACT FROM AUTHOR]

With human influences driving populations of apex predators into decline, more information is required on how factors affect species at national and global scales. However, camera-trap studies are seldom executed at a broad spatial scale. We demonstrate how uniting fine-scale studies and utilizing camera-trap data of non-target species is an effective approach for broadscale assessments through a case study of the brown hyaena Parahyaena brunnea. We collated camera-trap data from 25 protected and unprotected sites across South Africa into the largest detection/non-detection dataset collected on the brown hyaena, and investigated the influence of biological and anthropogenic factors on brown hyaena occupancy. Spatial autocorrelation had a significant effect on the data, and was corrected using a Bayesian Gibbs sampler. We show that brown hyaena occupancy is driven by specific co-occurring apex predator species and human disturbance. The relative abundance of spotted hyaenas Crocuta crocuta and people on foot had a negative effect on brown hyaena occupancy, whereas the relative abundance of leopards Panthera pardus and vehicles had a positive influence. We estimated that brown hyaenas occur across 66% of the surveyed camera-trap station sites. Occupancy varied geographically, with lower estimates in eastern and southern South Africa. Our findings suggest that brown hyaena conservation is dependent upon a multi-species approach focussed on implementing conservation policies that better facilitate coexistence between people and hyaenas. We also validate the conservation value of pooling fine-scale datasets and utilizing bycatch data to examine species trends at broad spatial scales. [ABSTRACT FROM AUTHOR]

We investigate the spatial organization and temporal dynamics of large-scale, coherent structures in turbulent Rayleigh–Bénard convection via direct numerical simulation of a 6.3 aspect-ratio cylinder with Rayleigh and Prandtl numbers of $9.6\times 10^7$ and $6.7$ , respectively. Fourier modal decomposition is performed to investigate the structural organization of the coherent turbulent motions by analysing the length scales, time scales and the underlying dynamical processes that are ultimately responsible for the large-scale structure formation and evolution. We observe a high level of rotational symmetry in the large-scale structure in this study and that the structure is well described by the first four azimuthal Fourier modes. Two different large-scale organizations are observed during the duration of the simulation and these patterns are dominated spatially and energetically by azimuthal Fourier modes with frequencies of 2 and 3. Studies of the transition between these two large-scale patterns, radial and vertical variations in the azimuthal energy spectra, as well as the spatial and modal variations in the system's correlation time are conducted. Rotational dynamics are observed for individual Fourier modes and the global structure with strong similarities to the dynamics that have been reported for unit aspect-ratio domains in prior works. It is shown that the large-scale structures have very long correlation time scales, on the order of hundreds to thousands of free-fall time units, and that they are the primary source for a horizontal inhomogeneity within the system that can be observed during a finite, but a very long-time simulation or experiment. [ABSTRACT FROM AUTHOR]

Ptychites is among the most widely distributed ammonoid genera of the Triassic and is namesake of a family and superfamily. However, representatives of the genus mostly show low-level phenotypic disparity. Furthermore, a large number of taxa are based on only a few poorly preserved specimens, creating challenges to determine ptychitid taxonomy. Consequently, a novel approach is needed to improve ptychitid diversity studies. Here, we investigate Ptychites spp. from the middle and late Anisian of Nevada. The species recorded include Ptychites embreei n. sp., which is distinguished by an average conch diameter that is much smaller and shows a more evolute coiling than most of its relatives. The new species ranges from the Gymnotoceras mimetus to the Gymnotoceras rotelliformis zones, which makes it the longest-ranging species of the genus. For the first time, the ontogenetic development of Ptychites was obtained from cross sections where possible. Cross-sectioning highlights unique ontogenetic trajectories in ptychitids. This demonstrates that, despite showing little phenotypic disparity, Ptychites was highly ontogenetically differentiated, and thus the high taxonomic diversity at the species level is justified for the species investigated. UUID: http://zoobank.org/5abe2487-8a00-4b48-adc7-ec7db7a097f7 [ABSTRACT FROM AUTHOR]

We study the fragmentation of a liquid drop that is hit by a laser pulse. The drop expands into a thin sheet that breaks by the radial expulsion of ligaments from its rim and the nucleation and growth of holes on the sheet. By combining experimental data from two liquid systems with vastly different time and length scales, we show how the early-time laser–matter interaction affects the late-time fragmentation. We identify two Rayleigh–Taylor instabilities of different origins as the prime cause of the fragmentation and derive scaling laws for the characteristic breakup time and wavenumber. The final web of ligaments results from a subtle interplay between these instabilities and deterministic modulations of the local sheet thickness, which originate from the drop deformation dynamics and spatial variations in the laser-beam profile. [ABSTRACT FROM AUTHOR]

Rosa x odorata (sect. Chinenses, Rosaceae) is an important species distributed only in Yunnan Province, China. There is an abundance of wild variation within the species. Using 22 germplasm resources collected from the wild, as well as R. chinensis var. spontanea, R. chinensis 'Old Blush' and R. lucidissima, this study involved morphological variation analysis, inter-trait correlation analysis, principal component analysis and clustering analysis based on 16 morphological traits. This study identified a high degree of morphological diversity in R. x odorata germplasm resources and the variation coefficients had a distribution range from 18.00 to 184.04%. The flower colour had the highest degree of variation, while leaflet length/width had the lowest degree of variation. Inter-trait correlation analysis revealed that there was an extremely significant positive correlation between leaflet length and leaflet width. There was also a significant positive correlation between the number of petals and duration of blooming, and the L* and a* values of flower colour were significantly negatively correlated. Principal component analysis screened five principal components with the highest cumulative contribution rate (81.679%) to population variance. Among the 16 morphological traits, style length, sepal width, flower diameter, flower colour, leaflet length and leaflet width were important indices that influenced the morphology of R. x odorata. This study offers guidance for the further development and utilization of R. x odorata germplasm resources. [ABSTRACT FROM AUTHOR]

We present a non-local 'microcontinuum' constitutive equation describing particle suspensions undergoing heterogeneous flows in the low Stokes and particle Reynolds number regime. Most prior models rely on mesoscale averages of structural dynamics that smear out non-local effects or otherwise place strong restrictions on flow type. We relieve this restriction here by ensemble averaging the exact equations that govern the suspension at the microscale, thereby obtaining explicit structure-property connections. The result is a pointwise, heterogeneous ensemble average of the suspension stress valid for suspended particles of arbitrary shape, size, composition and concentration, as well as arbitrary sources of heterogeneity, including non-uniform shear fields, heterogeneous force fields or spatially varying volume fractions. This non-local model accounts for spatial and temporal variations in the flow structure over arbitrary length and time scales. We express the microcontinuum constitutive equation as a superposition of gradient operators that automatically accounts for flow heterogeneity over any length scale larger than the particle size. Batchelor's result for a homogeneous suspension is recovered in the limit of zero gradients; non-zero gradient terms provide non-local corrections to the average stress and account for statistical heterogeneity in the suspension. We utilize energy methods to compute the influence of these gradient operators on the pointwise-averaged stress tensor, revealing a deep connection to the microhydrodynamics formalism. We apply this general framework to a dilute suspension of spherical particles and show that the resultant constitutive equations are consistent with experimental observations. [ABSTRACT FROM AUTHOR]

The green peafowl Pavo muticus is a highly threatened galliform species that was historically distributed widely across South-east Asia. Evidence shows a recent population decline and range contraction for this species, linked with habitat degradation and over-exploitation. This study aimed to determine the current known distribution across mainland South-east Asia and investigate potential habitat that could host remaining viable populations and contribute to the long-term survival of the species. We used locations from historical and recent records and habitat variables from a geographical information system database to model the probability of occurrence and classify key localities according to their relative importance for the species. Our results showed that the green peafowl probably occurs in less than 16% of its historical range across mainland South-east Asia and that remaining locations are fragmented. Four confirmed and two potential stronghold populations were identified for the species, based on the localities with high capacity to contribute to its long-term survival in large contiguous patches. These were in central Myanmar, western and northern Thailand, eastern Cambodia/south-central Viet Nam and northern Cambodia/southern Lao. Threats vary amongst countries, with continued habitat loss and degradation in many areas and hunting particularly acute in Viet Nam, Cambodia and Lao. Most of the remaining populations are in protected areas but the protection level varies widely. We propose conservation actions for each stronghold population, in accordance with the nature of the threats and protection level in each area, to prevent the local extinction of this species. [ABSTRACT FROM AUTHOR]

The Ross Ice Shelf (RIS) is host to a broadband, multimode seismic wavefield that is excited in response to atmospheric, oceanic and solid Earth source processes. A 34-station broadband seismographic network installed on the RIS from late 2014 through early 2017 produced continuous vibrational observations of Earth's largest ice shelf at both floating and grounded locations. We characterize temporal and spatial variations in broadband ambient wavefield power, with a focus on period bands associated with primary (10–20 s) and secondary (5–10 s) microseism signals, and an oceanic source process near the ice front (0.4–4.0 s). Horizontal component signals on floating stations overwhelmingly reflect oceanic excitations year-round due to near-complete isolation from solid Earth shear waves. The spectrum at all periods is shown to be strongly modulated by the concentration of sea ice near the ice shelf front. Contiguous and extensive sea ice damps ocean wave coupling sufficiently so that wintertime background levels can approach or surpass those of land-sited stations in Antarctica. [ABSTRACT FROM AUTHOR]

Tapeworms of the family Gryporhynchidae are endoparasites of fish-eating birds distributed worldwide. Currently the family contains 16 genera classified on the basis of the morphology of the rostellar apparatus, rostellar hooks and strobilar anatomy. However, the phylogenetic relationships among the genera are still unknown. In this study, sequences of the near complete 18S (SSU) and 28S (LSU) from rDNA of 13 species of gryporhynchids (adult specimens) representing eight genera (Cyclustera , Dendrouterina , Glossocercus , Gryporhynchidae gen. sp., Neovalipora , Paradilepis , Parvitaenia , Valipora) and one species of metacestode from fish (Neovalipora) were generated. Additionally, sequences of metacestodes of the genera Amirthalingamia , Neogryporhynchus , Paradilepis , Parvitaenia and Valipora from Africa recently added to the GenBank database were analysed. Phylogenetic relationships were inferred using maximum-likelihood (ML) and Bayesian inference of each (SSU and LSU) dataset. The phylogenetic analyses indicated that the family Gryporhynchidae is a well-supported monophyletic group within the Cyclophyllidea. The trees inferred with SSU and LSU datasets had similar topologies and suggested that the genera Glossocercus (two species sequenced) and Paradilepis (four spp.) are monophyletic. In contrast, Dendrouterina , Parvitaenia and Valipora are paraphyletic, suggesting that the species composition of these genera should be critically reviewed. Interestingly, species of the genera that use the same groups of definitive hosts such as herons (Ardeidae), cormorants (Phalacrocoracidae) and ibis (Threskiornithidae) are together in the phylogenetic tree, even though they differ markedly from each other in some morphological characters, especially shape and size of rostellar hooks. [ABSTRACT FROM AUTHOR]

The Kavango–Zambezi Transfrontier Conservation Area Programme promotes landscape-level connectivity between clusters of wildlife management areas in five neighbouring countries. However, declining regional biodiversity can undermine efforts to maintain, expand and link wildlife populations. Narratives promoting species connectivity should thus be founded on studies of system and state changes in key resources. By integrating and augmenting multiple data sources throughout eight wildlife management areas, covering 1.7 million ha, we report changes during 1978–2015 in the occurrence and distribution of 31 mammal species throughout a landscape linking the Greater Kafue System to adjacent wildlife management areas in Namibia and Botswana. Results indicate species diversity is largely unchanged in Kafue National Park and Mulobezi and Sichifulo Game Management Areas. However, 100% of large carnivore and 64% of prey diversity have been lost in the Simalaha areas, and there is no evidence of migrational behaviour or species recolonization from adjacent wildlife areas. Although temporal sampling scales influence the definition of species occupancy and distribution, and data cannot elucidate population size or trends, our findings indicate an emerging connectivity bottleneck within Simalaha. Evidence suggests that at current disturbance levels the Greater Kafue System, Zambia's majority component in the Kavango–Zambezi Transfrontier Conservation Area, is becoming increasingly isolated at the trophic scale of large mammals. Further investigations of the site-specific, interacting drivers influencing wildlife distribution and occurrence are required to inform appropriate conservation interventions for wildlife recovery in key areas identified to promote transboundary connectivity in the Kavango–Zambezi Transfrontier Conservation Area. [ABSTRACT FROM AUTHOR]

We report a systematic study of spatial variations of the probability density function (PDF) $P(\unicode[STIX]{x1D6FF}T)$ for temperature fluctuations $\unicode[STIX]{x1D6FF}T$ in turbulent Rayleigh–Bénard convection along the central axis of two different convection cells. One of the convection cells is a vertical thin disk and the other is an upright cylinder of aspect ratio unity. By changing the distance $z$ away from the bottom conducting plate, we find the functional form of the measured $P(\unicode[STIX]{x1D6FF}T)$ in both cells evolves continuously with distinct changes in four different flow regions, namely, the thermal boundary layer, mixing zone, turbulent bulk region and cell centre. By assuming temperature fluctuations in different flow regions are all made from two independent sources, namely, a homogeneous (turbulent) background which obeys Gaussian statistics and non-uniform thermal plumes with an exponential distribution, we obtain the analytic expressions of $P(\unicode[STIX]{x1D6FF}T)$ in four different flow regions, which are found to be in good agreement with the experimental results. Our work thus provides a unique theoretical framework with a common set of parameters to quantitatively describe the effect of turbulent background, thermal plumes and their spatio-temporal intermittency on the temperature PDF $P(\unicode[STIX]{x1D6FF}T)$. [ABSTRACT FROM AUTHOR]

Radiodonta, apex Cambrian predators such as Anomalocaris have been known from the Kinzers Formation (Cambrian Series 2, Stage 4 – Pennsylvania, USA) for nearly 100 years. Work over the last ten years, mainly on radiodont material from the Chengjiang (Cambrian Series 2, Stage 3 – Yunnan, China) and Burgess Shale (Miaolingian, Wuliuan – British Columbia, Canada), has greatly improved our knowledge of the diversity and disparity of radiodonts and their frontal appendages, including the description of new species, genera and families. Previous work identified two species of radiodonts from the Kinzers Formation: Anomalocaris pennsylvanica Resser, 1929 and Anomalocaris ? cf. pennsylvanica based on isolated frontal appendage material (Briggs, 1979). A restudy of Kinzers Formation material shows that only some of the specimens can be confirmed as Anomalocaris pennsylvanica , and a number of specimens previously attributed to Anomalocaris in fact belong to other more recently discovered radiodont genera Amplectobelua and Tamisiocaris. This reinterpretation makes the Kinzers Formation the most diverse Cambrian Stage 4 Burgess Shale Type Lagerstätten in terms of number of radiodont species. This assemblage includes the youngest known Tamisiocaris and the first from outside Greenland, the only Amplectobelua from Stage 4 and the oldest from Laurentia, two specimens tentatively assigned to the recently described Chengjiang genus Laminacaris , and the endemic Anomalocaris pennsylvanica. The identification of these new radiodont taxa increases the total known diversity of the Kinzers Formation to more than ten species, and so it should now be considered a Tier 2 Lagerstätte. [ABSTRACT FROM AUTHOR]

Glacier sliding over small obstacles relies on melting on their upstream sides and refreezing downstream. Previous treatments have appealed to 'pressure melting' as the cause of the spatial variations in melting temperature that drive this regelation process. However, we show that typical liquid pressure variations across small obstacles are negligible and therefore variations in ice pressure closely approximate variations in effective stress. For a given change in effective stress, the equilibrium melting temperature changes by an order of magnitude more than when the pressure of ice and liquid both change by an equal amount. In consequence, the temperature gradients that drive heat flow across small obstacles are larger than previously recognized and the rate of regelation is faster. Under typical conditions, the transition wavelength at which ice deformation and regelation contribute equally is of m-scale, several times longer than previous predictions, which have been reported to underestimate field inferences. [ABSTRACT FROM AUTHOR]

The Lower Meuse Valley crosses the Roer Valley Rift System and provides an outstanding example of well-preserved late glacial and Holocene river terraces. The formation, preservation, and morphology of these terraces vary due to reach-specific conditions, a phenomenon that has been underappreciated in past studies. A detailed palaeogeographic reconstruction of the terrace series over the full length of the Lower Meuse Valley has been performed. This reconstruction provides improved insight into successive morphological responses to combined climatic and tectonic external forcing, as expressed and preserved in different ways along the river. New field data and data obtained from past studies were integrated using a digital mapping method in GIS. Results show that late glacial river terraces with diverse fluvial styles are best preserved in the Lower Meuse Valley downstream sub-reaches (traversing the Venlo Block and Peel Block), while Holocene terrace remnants are well-developed and preserved in the upstream sub-reaches (traversing the Campine Block and Roer Valley Graben). This reach-to-reach spatial variance in river terrace preservation and morphology can be ascribed to tectonically driven variations in river gradient and subsurface lithology, and to river-driven throughput of sediment supply. [ABSTRACT FROM AUTHOR]

With the development of remote sensing and geostatistical technology, complex environmental variables are increasingly easily quantified and applied in modelling soil organic carbon (SOC). However, this emphasizes data redundancy and multicollinearity problems adding to the difficulty in selecting dominant influential auxiliary variables and uncertainty in estimating SOC stocks. The current paper considers the spatial characteristics of SOC density (SOCD) to construct prediction models of SOCD on the basis of reducing the data dimensionality and complexity using the principal component analysis (PCA) method. A total of 260 topsoil samples were collected from Chahe town, China. Eight environmental variables (elevation, aspect, slope, normalized difference vegetation index, normalized difference moisture index, nearest distance to construction area and road, and land use degree comprehensive index) were pre-analysed by PCA and then extracted as the main principal component variables to construct prediction models. Two geostatistical approaches (ordinary kriging and ordinary co-kriging) and two regression approaches (ordinary least squares and geographically weighted regression (GWR)) were used to estimate SOCD. Results showed that PCA played an important role in reducing the redundancy and multicollinearity of the auxiliary variables and GWR achieved the highest prediction accuracy in these four models. GWR considered not only the spatial characteristics of SOCD but also the related valuable information of the auxiliary attributes. In summary, PCA-GWR is a promising spatial method used here to predict SOC stocks. [ABSTRACT FROM AUTHOR]

Objective: To investigate spatial heterogeneity of stunting prevalence among children in Côte d'Ivoire and examine changes in stunting between 1994 and 2011, to assess the impact of the 2002-2011 civil war that led to temporary partitioning of the country.Design: Data from 1994, 1998 and 2011 Côte d'Ivoire Demographic and Health Surveys (DHS) were analysed using a geostatistical approach taking into account spatial autocorrelation. Stunting data were interpolated using ordinary kriging; spatial clusters with high and low stunting prevalence were identified using Kulldorff spatial scan statistics. Multilevel multivariable logistic regression was then carried out, with year of survey as the main independent variable and an interaction term for time by geographic zone (Abidjan, South, North).Setting: Côte d'Ivoire, West Africa.Subjects: Children aged 0-35 months included in three DHS (n 6709).Results: Overall stunting prevalence was 30·7, 28·7 and 27·8 % in 1994, 1998 and 2011, respectively (P=0·32). Clusters with high prevalence were found in 1994 (in the West region, P<0·001) and 1998 (in the West and North-West regions, P<0·01 and P=0·01, respectively), but not in 2011. Abidjan was included in a cluster with low prevalence in all surveys (P<0·05). Risk of stunting did not change between 1994 and 2011 at national level (adjusted OR; 95 % CI: 1·39; 0·72, 2·64), but decreased in the South (0·74; 0·58, 0·94) and increased from 1998 to 2011 in Abidjan (1·96; 1·06, 3·64).Conclusions: In Côte d'Ivoire, significant changes in stunting prevalence were observed at the sub-national level between 1994 and 2011. [ABSTRACT FROM AUTHOR]

Three species of belonid fish, Belone belone gracilis Lowe, 1839, Belone svetovidovi Collette & Parin, 1970 and Tylosurus acus imperialis (Rafinesque, 1810), caught off the eastern Tunisian coast were infected with eight species of Digenea. Among these, four species were commonly found in B. b. gracilis and are new host records for B. svetovidovi. They are: Lecithostaphylus retroflexus (Molin, 1859), Tergestia acanthocephala (Stossich, 1887) Stossich, 1899 and Aponurus laguncula Looss, 1907 in the intestine, and the metacercaria Condylocotyla pilodora Pearson and Prévot, 1985 in the pericardial sac. Four other digenean species were recorded from T. a. imperialis: Lecithostaphylus tylosuri Châari et al., 2013 and Tetrochetus coryphaenae Yamaguti, 1934 in the intestine, Oesophagotrema mediterranea Châari et al., 2011 in the oesophagus and vomer teeth, and Sclerodistomoides pacificus Kamegai, 1971 in the gall bladder. Tetrochetus coryphaenae and S. pacificus represent new host and geographical records. The spatial variation of digenean parasites within belonid host species is discussed. [ABSTRACT FROM AUTHOR]

Strong geographical variations have been noted in the twinning rate (TWR). In general, the rate is high among people of African origin, intermediate among Europeans, and low among most Asiatic populations. In Europe, there tends to be a south–north cline, with a progressive increase in the TWR from south to north and a minimum around the Basque provinces. The highest TWRs in Europe have been found among the Nordic populations. Furthermore, within larger populations, small isolated subpopulations have been identified to have extreme, mainly high, TWRs. In the study of the temporal variation of the TWR in Norway, we consider the period from 1900 to 2014. The regional variation of the TWR in Norway is analyzed for the different counties for two periods, 1916–1926 and 1960–1988. Heterogeneity between the regional TWRs in Norway during 1916–1926 was found, but the goodness of fit for the alternative spatial models was only slight. The optimal regression model for the TWR in Norway has the longitude and its square as regressors. According to this model, the spatial variation is distributed in a west–east direction. For 1960–1988, no significant regional variation was observed. One may expect that the environmental and genetic differences between the counties in Norway have disappeared and that the regional TWRs have converged towards a common low level. [ABSTRACT FROM PUBLISHER]

We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection. [ABSTRACT FROM AUTHOR]