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Beyond ~13.9 cal kBP, the IntCal20 radiocarbon (14C) calibration curve is based upon combining data across a range of different archives including corals and planktic foraminifera. In order to reliably incorporate such marine data into an atmospheric curve, we need to resolve these records into their constituent atmospheric signal and marine reservoir age. We present results of marine reservoir age simulations enabling this resolution, applying the LSG ocean general circulation model forced with various climatic background conditions and with atmospheric radiocarbon changes according to the Hulu Cave speleothem record. Simulating the spatiotemporal evolution of reservoir ages between 54,000 and 10,700 cal BP, we find reservoir ages between 500 and 1400 yr in the low- and mid-latitudes, but also more than 3000 yr in the polar seas. Our results are broadly in agreement with available marine radiocarbon reconstructions, with the caveat that continental margins, marginal seas, or tropical lagoons are not properly resolved in our coarse-resolution model.
What is the role of Northeastern agricultural products in the US food system? This paper presents a typology that categorizes where agricultural production and distribution of a specific geographic area, in this case a multi-state region, fits within the US food system. The place of each food is defined based on its production volume, scope of distribution, market timing and agro-ecological niche. Six distinct roles that a region might play in supplying food are identified: (a) the region is a national production center, (b) the region is a seasonally important supplier, (c) regional production and distribution is the primary scale for supplying a food, (d) the product occupies an agro-ecological niche, (e) a product is a co-product of another industry in the region, and (f) the product is marketed explicitly for its geographic provenance as a local or regional product. Illustrative examples of each role are provided from the research of the Enhancing Food Security in the Northeast (EFSNE) regional food systems project. The examples draw from a variety of methodological approaches including regional self-reliance analysis, product case studies, supply chain models, and examination of spatial and temporal patterns in crop and livestock production and marketing. While presented in the context of the Northeast, the typology would likely be valuable for characterizing other regions of the country. We need such a typology to better understand and communicate the value of geographically dispersed agricultural production to creating a resilient food system, thereby improving our decisions of how to respond to future agricultural challenges
The lower Mississippian Ballagan Formation of northern Britain is one of only two successions worldwide to yield the earliest known tetrapods with terrestrial capability following the end-Devonian mass extinction event. Studies of the sedimentary environments and habitats in which these beasts lived have been an integral part of a major research project into how, why and under what circumstances this profound step in the evolution of life on Earth occurred. Here, a new palaeogeographic map is constructed from outcrop data integrated with new and archived borehole material. The map shows the extent of a very low-relief coastal wetland developed along the tropical southern continental margin of Laurussia. Coastal floodplains in the Midland Valley and Tweed basins were separated from the marginal marine seaway of the Northumberland–Solway Basin to the south by an archipelago of more elevated areas. A complex mosaic of sedimentary environments was juxtaposed, and included fresh and brackish to saline and hypersaline lakes, a diverse suite of floodplain palaeosols and a persistent fluvial system in the east of the region. The strongly seasonal climate led to the formation of evaporite deposits alternating with flooding events, both meteoric and marine. Storm surges drove marine floods from the SW into both the western Midland Valley and Northumberland–Solway Basin; marine water also flooded into the Tweed Basin and Tayside in the east. The Ballagan Formation is a rare example in the geological record of a tropical, seasonal coastal wetland that contains abundant, small-scale evaporite deposits. The diverse sedimentary environments and palaeosol types indicate a network of different terrestrial and aquatic habitats in which the tetrapods lived.
The biocomponent ratio in liquid fuels as well as the usage of renewable resources for fuel consumption in the transport sector needs to be increased as a result of EU directive 2003/30/EC. Based on radiocarbon (14C) measurements, it should be relatively simple and fast to measure the weight percentage of the fossil and biological sources by accelerator mass spectrometry (AMS) as recommended in the ASTM D 6866-12 and EN 16640 standards. In this study, a relatively easy and fast sample preparation and measurement method based on AMS measurements was developed at the Hertelendi Laboratory of Environmental Studies (HEKAL) using reference samples from the Hungarian MOL Nyrt. oil company. Considering the recent EU regulation for mixing rates of liquid fuels in the transport sector (0.7–2% biofuel content) and the projected higher rates (2–10% biofuel content), the method is applicable to determine fatty acid methyl ester (FAME) and/or hydrotreated vegetable oil (HVO) derived proportions of fuel blends with a 1σ uncertainty better than±0.3% m/m.
Synthesis and solubility studies of brizziite, NaSbO3, have been undertaken to determine the possible role of this rare secondary phase in the immobilization of Sb under supergene conditions and the conditions responsible for its formation in the supergene zone. Solubility studies were undertaken at T = 298.15 K. A value of ΔGfө) (NaSbO3, s, 298.15 K) = –806.66 ± 1.4 kJ mol–1 was derived. Calculations involving tripuhyite, FeSbO4, byströmite, MgSb2O6, ordoñezite, ZnSb2O6 and rosiaite, PbSb2O6, show that brizziite is a thermodynamically stable phase only at negligible activities of Pb2+(aq) at high pH and high salinity. Calculations involving mopungite Na[Sb(OH)6] combined with reported mineral associations suggest that mopungite is the thermodynamically unstable precursor to brizziite and its presence in natural settings must be due to kinetic stability. This explains why brizziite is such a rare secondary phase and therefore why it cannot exert any significant influence on the dispersion of Sb in the supergene environment.
To examine the comparability of fruit and vegetable (F&V) intake data in the USA from 2001 to 2014 between data acquired from two national data collection programmes.
Cross-sectional analysis. Linear regression models estimated trends in daily per capita intake of total F&V. Pooled differences in intake of individual F&V (n 109) were examined by processing form (fresh, frozen, canned, dried and juice).
What We Eat in America (WWEIA, 2001–2014) and Loss-Adjusted Food Availability data series (LAFA, 2001–2014).
No temporal trends were observed in daily per capita intake of total F&V from 2001 to 2014 using WWEIA and LAFA. Modest differences between WWEIA and LAFA were observed in mean pooled intake of most individual F&V.
WWEIA and LAFA produced similar estimates of F&V intake. However, WWEIA may be best suited for monitoring intake at the national level because it allows for the identification of individual F&V in foods with multiple ingredients, and it is structured for sub-population analysis and covariate control. LAFA does retain advantages for other research protocols, specifically by providing the only nationally representative estimates of food losses at various points in the food system, which makes it useful for examining the adequacy of the food supply at the agricultural, retail and consumer levels.
Opportunities for alternative swine production and marketing are emerging across the value chain. Given the developing nature of the differentiated pork industry, measurements of niche performance and success are not yet fully known. For this reason, the objectives of this study were to determine performance metrics across all major life phases for niche pork production and compare such metrics with national averages of conventional commodity pork production. Additionally, this study aimed to quantify producers’ reasoning and barriers to successfully raising niche swine. Niche meat producers in the USA self-identified for this study (n = 176); their swine production had alternative characteristics that included small- to mid-sized farms, farrow-to-finish operations, heritage breeds, housing with bedding and outdoor or pasture access, no use of antibiotics (sub-therapeutic for growth promotion or no antibiotics ever), vegetarian feed, diverse agricultural enterprises and alternative marketing avenues. This study focused on the metric categories regarding reproduction, mortality, culling and growth characteristics. The niche system produced approximately 15% fewer weaned piglets per bred sow per year than the conventional system due to fewer breeding cycles, smaller litters and higher piglet mortality in alternative production. Similarly, niche production finished 12% fewer hogs per bred sow per year than conventional production. Regarding age benchmarks of finishing and breeding, the niche system averaged 18 additional days to finish hogs at a standardized market weight of 124 kg. Likewise, niche production gilts were first bred at 283 days, whereas conventional production breeds gilts at 225 days. All directly comparable metrics were found to be statistically significant with 95% confidence for the one-sample test of means. Regarding farmer attitudes toward niche pork, survey participants shared personal reasons for raising swine and barriers to successful niche production. Choosing niche over commodity swine, participants’ reasons were grouped into three intra-related categories: (1) farm and producer viability, (2) animal and environmental welfare, and (3) consumer preference and taste. Despite these benefits, participants were faced with numerous challenges, which were organized into four intra-related categories: (1) alternative production requirements, restrictions and knowledge; (2) access and affordability of credit and inputs; (3) alternative supply chain for processing, marketing and customers; and (4) non-niche production competition and governmental policies. In sum, the success of these niche pork operations equates to high welfare for the pigs, economic viability for the operation, personal enjoyment for the farmer, customer satisfaction with meat flavor and quality, and responsible environmental practices, inclusive of many components of an alternative food system.
We agree with Lake and colleagues on their list of “key ingredients” for building human-like intelligence, including the idea that model-based reasoning is essential. However, we favor an approach that centers on one additional ingredient: autonomy. In particular, we aim toward agents that can both build and exploit their own internal models, with minimal human hand engineering. We believe an approach centered on autonomous learning has the greatest chance of success as we scale toward real-world complexity, tackling domains for which ready-made formal models are not available. Here, we survey several important examples of the progress that has been made toward building autonomous agents with human-like abilities, and highlight some outstanding challenges.
The mechanism of trailing vortex wandering has long been debated and is often attributed to either wind-tunnel effects or an instability. Using particle image velocimetry data obtained in the wake of a NACA0012 airfoil, we remove the effect of wandering from the measured velocity field and, through a triple decomposition, recover the coherent wandering motion. Based on this wandering motion, the most energetic structures are computed using the proper orthogonal decomposition (POD) and exhibit a helical mode with an azimuthal wavenumber of
whose kinetic energy grows monotonically in the downstream direction. To investigate the nature of the vortex wandering, we perform a spatial stability analysis of a matched Batchelor vortex. The primary stability mode is found to be marginally stable and nearly identical in both size and structure to the leading POD mode. The strikingly similar structure, coupled with the measured energy growth, supports the proposition that the vortex wandering is the result of an instability. We conclude that the cause of the wandering is the non-zero radial velocity of the
mode on the vortex centreline, which acts to transversely displace the trailing vortex, as observed in experiments. However, the marginal nature of the stability mode prevents a definitive conclusion regarding the specific type of instability.
Mitochondrial gene markers have been used in molecular systematics for well over 25 years and they have an established role in resolving phylogenetic and ecological patterns in a multitude of phyla and across a range of taxonomic levels (Randi 2000; Avise 2004). However, there are some problems and limitations in their use; in-depth studies over the last three decades have shown that mitochondrial DNA (mtDNA) is not always inherited clonally through the maternal line, nor is it evolving neutrally (Ballard and Whitlock 2004; Galtier et al. 2009). Also, PCR-based approaches can inadvertently amplify nuclear copies of mitochondrial genes (NUMTs) thus introducing non-homologous signal to datasets (Bensasson et al. 2001). However, for the molecular taxonomist and systematist ‘mtDNA is the most convenient and cheapest solution when a new species has to be genetically explored in the wild’ (Galtier et al. 2009, p. 4541).
Meanwhile, the use of entire mitochondrial genomes (mitogenomes) in systematics has had a varied history since they became available as a tractable source of phylogenetic data. Often met with either enthusiasm or hostility it is clear that their reliability as accurate estimators of species trees has been dependent upon our knowledge of the mitogenomes themselves and how to model the evolutionary signal contained within while accounting for lineage-specific differences in rate heterogeneity and nucleotide composition. Only through denser taxonomic sampling across the Metazoa have mitogenomes become better understood, easier to characterize, and more attractive as a source of homologous markers across multiple levels of organization; from nucleotides to amino acids, from gene content to genetic code and gene order. In order to expand on the known mitogenomes, NGS techniques offer a diversity of methods for fast characterization of novel mitogenomes but, depending on the starting material and the NGS platform, there remain barriers as to which techniques might be most cost-effective and reliable. Here we review recent published studies, report on unpublished work of our own, provide empirical evidence from simulations and cast a critical eye over the prospects and limitations we currently see for reliable use of NGS and high-throughput mitogenome sequencing in the context of systematics and biodiversity studies.
The production of livestock feed in the USA is geographically concentrated, which poses several risks. Extreme weather events and disease outbreaks have the potential to disrupt production in these areas, which could reduce the national output of meat, dairy and eggs. Additionally, geographically concentrated livestock and feed production systems have been observed to contribute excessive nutrient loads to surrounding soil and water bodies, thereby threatening environmental sustainability. Geographic relocation of production systems has been proposed as an adaptation strategy to increase system resilience and this could take the shape of more geographically dispersed livestock feed production. We estimate the degree to which the demand for meat, dairy and eggs in the Northeast region is met with current levels of regional feed and livestock production, a term that we refer to as regional self-reliance. We combine mean annual (2001–2010) data on Northeast regional land use; crop output; meat, dairy and egg output; and food consumption with a livestock feed requirements model. An annual mean of over 6.1 million ha of land in the Northeast was dedicated to livestock feed from 2001 to 2010, with nearly 80% located in just three states (Pennsylvania, New York and West Virginia). The region is a net importer of livestock feed (in terms of total digestible nutrients and crude protein), as well as meat, dairy and eggs (in terms of total human-edible energy and protein). This is the result of a confluence of long-term regional trends that include the movement of agricultural production out of the region with a concomitant increase in the regional population and an increase in the national demand for meat, dairy and eggs. Limited slaughter output in the region is a key limiting factor to increasing the region's self-reliance for livestock products.
The eastern bettong Bettongia gaimardi, a potoroid marsupial, has been extinct on the Australian mainland since the 1920s. Sixty adult bettongs were reintroduced from the island of Tasmania to two predator-free fenced reserves on mainland Australia. We examined baseline health parameters (body weight, haematology and biochemistry, parasites and infectious disease exposure) in a subset of 30 (13 male, 17 female) individuals at translocation and again at 12–24 months post-reintroduction. The mean body weight increased significantly post-reintroduction but there were no significant differences in body weight between the two reintroduction sites or between the sexes in response to reintroduction. Differences were evident in multiple haematological and biochemical variables post-reintroduction but there were few differences between the two reintroduced populations or between the sexes in response to reintroduction. Ectoparasite assemblages differed, with five of 13 species failing to persist, and an additional four species were identified post-reintroduction. None of the bettongs had detectable antibodies to the alphaherpesviruses Macropodid herpesvirus 1 and 2 post-reintroduction, including one individual that was seropositive at translocation. Similarly, the novel gammaherpesvirus potoroid herpesvirus 1 was not detected by polymerase chain reaction (PCR) in any of the bettongs post-reintroduction, including one individual that was PCR-positive at translocation. None of the bettongs had detectable antibodies to Toxoplasma gondii either at translocation or post-reintroduction. Our data demonstrate changing baseline health parameters in eastern bettongs following reintroduction to the Australian mainland are suggestive of improved health in the reintroduced populations, and provide additional metrics for assessing the response of macropodoids to reintroduction.
In order to clarify the roles that secondary minerals may have in determining the extent of dispersion of Sb in the supergene environment, syntheses and stability studies of the Sb(V) oxides byströmite, MgSb2O6, ordoñezite, ZnSb2O6 and rosiaite, PbSb2O6, have been undertaken. Solubilities in aqueous HNO3 were determined at 298.2 K and the data obtained used to calculate values of Δ at the same temperature. The derived Δ(s, 298.2 K) values for MgSb2O6 (–1554.1 ±3.6 kJ mol–1), ZnSb2O6 (–1257.0 ±2.6 kJ mol–1) and PbSb2O6 (–1154.2 ±2.6 kJ mol–1) have been used in subsequent calculations to determine their relative stabilities and relationships with other secondary Sb minerals.