Spatial Patterns Of Accumulation Research Articles

Spatial equity of urban parks from the perspective of recreational opportunities and recreational environment quality: A case study in Singapore

Spatial equity in urban park recreational services can significantly contribute to sustainable urban planning. However, there are shortcomings in research comparing the spatial equity of different categories of parks and urban parks overall from the perspective of recreational opportunities and recreational environment quality available to residents across various neighborhoods. In this paper, emphasizing park access within a 10-minute walk, we proposed an evaluation system at the neighborhood level for regional parks, community parks, and urban parks overall (regional and community parks combined) from this under-researched perspective. Taking Singapore as a case study, the feasibility of this evaluation system has been verified. We applied Lorenz curve, Gini coefficient, locational entropy, and spatial autocorrelation analysis to compare the differences of horizontal spatial equity and spatial distribution patterns of different categories of parks and urban parks overall from the perspective of recreational opportunities and recreational environment quality. Results showed that the horizontal spatial inequity of recreational opportunities is higher than that of recreational environment quality with respect to regional parks, community parks, and urban parks overall. Compared with regional parks, community parks have a greater effect on improving the horizontal spatial equity of recreational opportunities and recreational environment quality of urban parks overall. Park recreational opportunities and recreational environment quality available to residents in each neighborhood have significant spatial accumulation patterns. The evaluation system and its application enable a more comprehensive assessment of the spatial distribution of neighborhood-level park recreational opportunities and recreational environment quality.

Diffusion law of coal gangue slurry and the application of fluidized filling technology of gangue in caving area

In order to deeply study the basic characteristics, diffusion laws, and flow laws of coal gangue and coal gangue slurry, the basic characteristic parameters of coal gangue and coal gangue slurry were obtained through particle size distribution test, electron microscope scanning test, X-ray diffraction test, X-ray fluorescence spectrum test, and angle of repose test. The conveying performance test of coal gangue slurry was carried out, and based on this, a simulation test of coal gangue slurry caving areas was designed. The diffusion and flow laws of coal gangue slurry under the same inclination angle were summarized, and the field test of fluidization filling in the caving areas was conducted. The results show that: (1) The water-to-gangue ratio was the main controlling factor for the conveying performance of coal gangue slurry. The extensibility, slump, and bleeding rate of the coal gangue slurry increased with the increase of the water-to-gangue ratio. (2) The diffusion profile of coal gangue slurry at different dip angles was arc-shaped, and the diffusion distance of slurry increased with the increase of infiltration time. However, there were differences in the sustained diffusion ability of different dip angles. (3) At the same time interval, the spatial accumulation patterns of scattered gangue in different regions will lead to differences in the diffusion speed of the slurry. (4) Both burying and hanging pipes in the falling area can safely and efficiently fill the gangue slurry. The diffusion distance of the caving areas in the test working face was basically consistent with the diffusion distance of the slurry in the simulation test of the coal gangue slurry caving areas.

Microspatial distribution of trace elements in feline dental hard tissues: early life exposure to essential and toxic elements.

Trace elements play a key role in dental tissue development, as dental hard tissues accumulate both essential and toxic trace elements during mineralization. Characterization of the spatial accumulation pattern of trace elements may provide insight into exposure to toxic elements over time and to the nature of disease processes affecting the hard dental tissues. Here, we present the first report of the use of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to map the microspatial distribution of multiple trace elements, essential and toxic, across feline dental hard tissues. Eleven teeth were extracted from 8 cats. Nine teeth were from 7 cats diagnosed with idiopathic tooth resorption on intraoral radiographs prior to extraction. Two teeth were included from a cadaver that had no signs of tooth resorption on intraoral radiographs. The normal dental tissue was analyzed from each sample using LA-ICP-MS to map the microspatial distribution of essential and toxic trace elements across feline enamel, dentin, and cementum. Results showed a higher accumulation of barium and strontium in coronal dentin as compared to root dentin. The timing of the accumulation mirrors nursing timelines seen in teeth from human and non-human primates, consistent with barium and strontium being sourced from maternal milk. Results also showed a higher uptake of lead in the coronal dentin, suggesting this lead exposure was likely passed from mother to offspring. This work characterizes a baseline for elemental distribution in feline teeth linked to early life exposure to toxic elements such as lead and provides a framework for future studies investigating long-term environmental exposures to trace elements, essential and toxic, and their involvement in feline systemic and dental diseases.

Metabolome, Plant Hormone, and Transcriptome Analyses Reveal the Mechanism of Spatial Accumulation Pattern of Anthocyanins in Peach Flesh.

Anthocyanins are important secondary metabolites in fruits, and anthocyanin accumulation in the flesh of peach exhibits a spatial pattern, but the relevant mechanism is still unknown. In this study, the yellow-fleshed peach, cv. 'Jinxiu', with anthocyanin accumulation in the mesocarp around the stone was used as the experimental material. Red flesh (RF) and yellow flesh (YF) were sampled separately for flavonoid metabolite (mainly anthocyanins), plant hormone, and transcriptome analyses. The results showed that the red coloration in the mesocarp was due to the accumulation of cyanidin-3-O-glucoside, with an up-regulation of anthocyanin biosynthetic genes (F3H, F3'H, DFR, and ANS), transportation gene GST, and regulatory genes (MYB10.1 and bHLH3). Eleven ERFs, nine WRKYs, and eight NACs were also defined as the candidate regulators of anthocyanin biosynthesis in peach via RNA-seq. Auxin, cytokinin, abscisic acid (ABA), salicylic acid (SA), and 1-aminocyclopropane-1-carboxylic acid (ACC, ethylene precursor) were enriched in the peach flesh, with auxin, cytokinin, ACC, and SA being highly accumulated in the RF, but ABA was mainly distributed in the YF. The activators and repressors in the auxin and cytokinin signaling transduction pathways were mostly up-regulated and down-regulated, respectively. Our results provide new insights into the regulation of spatial accumulation pattern of anthocyanins in peach flesh.

Transcription factor GLK1 promotes anthocyanin biosynthesis via an MBW complex-dependent pathway in Arabidopsis thaliana.

Anthocyanins are important natural plant pigments and play diverse roles in plant growth and adaptation. Anthocyanins function as screens to protect photosynthetic tissues from photoinhibition. However, the regulatory mechanisms underlying the biosynthesis and spatial accumulation pattern of anthocyanins remain some unresolved issues. Here, we demonstrate that the GARP-type transcription factor GOLDEN2-LIKE 1 (GLK1) functions as a positive factor in anthocyanin accumulation. GLK1 enhances the transcriptional activation activities of MYB75, MYB90, and MYB113 via direct protein-protein interactions to increase the expression of anthocyanin-specific biosynthetic genes. Anthocyanins accumulate in an acropetal manner in Arabidopsis. We also found that the expression pattern of GLK1 overall mimicked the accumulation pattern of anthocyanin from the base of the main stem to the shoot apex. Based on these findings, we established a working model for the role of GLK1 in anthocyanin accumulation and propose that GLK1 mediates the spatial distribution pattern of anthocyanins by affecting the transcriptional activation activities of MYB75, MYB90, and MYB113.

Equine odontoclastic tooth resorption and hypercementosis (EOTRH): microspatial distribution of trace elements in hypercementosis-affected and unaffected hard dental tissues

Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) is a common, painful and poorly understood disease. Enamel, dentin and cementum accumulate both essential and toxic trace elements during mineralization. Characterization of the spatial accumulation pattern of trace elements may provide insight into the role that toxic elements play and inform biological processes affecting these hard dental tissues for future research. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to map the distribution of multiple trace elements and heavy metals across equine healthy and diseased (hypercementosis-affected) hard dental tissues among four teeth extracted from horses with EOTRH. Results showed banding patterns of some trace elements (lead, strontium, barium), reflecting the temporal component of accumulation of trace elements during dentin mineralization. Essential elements zinc and magnesium did not show banding patterns. Comparison to the unaffected cementum and dentin adjacent to the hypercementosis region showed that there is an underlying incremental pattern in the uptake of some metals with spatial irregularities. This supports a possible metabolic change involved in hypercementosis lesion development. This represents the first use of LA-ICP-MS to study the microspatial distribution of trace elements in equine teeth, establishing a baseline for elemental distribution in normal and EOTRH impacted dental hard tissue.

Analyzing spatial distribution between 18F-fluorodeoxyglucose and 18F-boronophenylalanine positron emission tomography to investigate selection indicators for boron neutron capture therapy

Background18F-FDG PET is often utilized to determine BNCT selection due to the limited availability of 18F-BPA PET, which is performed by synthesizing 18F into the boron drug used for BNCT, although the uptake mechanisms between those are different. Additionally, only a few non-spatial point parameters, such as maximum SUV (SUVmax), have reported a correlation between those in previous studies. This study aimed to investigate the spatial accumulation pattern between those PET images in tumors, which would be expected to either show higher uptake on 18F-BPA PET or be utilized in clinical, to verify whether 18F-FDG PET could be used as a selection indicator for BNCT.MethodsA total of 27 patients with 30 lesions (11 squamous cell carcinoma, 9 melanoma, and 10 rhabdomyosarcoma) who received 18F-FDG and 18F-BPA PET within 2 weeks were enrolled in this study. The ratio of metabolic tumor volumes (MTVs) to GTV, histogram indices (skewness/kurtosis), and the correlation of total lesion activity (TLA) and non-spatial point parameters (SUVmax, SUVpeak, SUVmin, maximum tumor-to-normal tissue ratio (Tmax/N), and Tmin/N) were evaluated. After local rigid registration between those images, distances of locations at SUVmax and the center of mass with MTVs on each image and similarity indices were also assessed along its coordinate.ResultsIn addition to SUVmax, SUVpeak, and Tmax/N, significant correlations were found in TLA. The mean distance in SUVmax was 25.2 pm 24.4; {text{mm}} and significantly longer than that in the center of mass with MTVs. The ratio of MTVs to GTV, skewness, and kurtosis were not significantly different. However, the similarities of MTVs were considerably low. The similarity indices of Dice similarity coefficient, Jaccard coefficient, and mean distance to agreement for MTV40 were 0.65 pm 0.21, 0.51 pm 0.21, and 0.27 pm 0.30 cm, respectively. Furthermore, it was worse in MTV50. In addition, spatial accumulation patterns varied in cancer types.ConclusionsSpatial accumulation patterns in tumors showed low similarity between 18F-FDG and 18F-BPA PET, although the various non-spatial point parameters were correlated. In addition, the spatial accumulation patterns were considerably different in cancer types. Therefore, the selection for BNCT using 18F-FDG PET should be compared carefully with using 18F-FBPA PET.

Tau heterogeneity in Aβ positive patients

AbstractBackgroundA substantial proportion of individuals on the AD continuum have tau PET burden that is not elevated, suggesting that they may be in an earlier stage on the AD continuum and/or have other copathologies that account for their impairment. To examine these possibilities, we compared Aβ+, cognitively impaired individuals with lower tau burden to theirAβ+ high tau counterparts across a variety of biomarker and clinical measurements.MethodWe identified Aβ+, impaired (MCI or AD) patients from ADNI with high and low tau burden using contemporaneous amyloid PET (florbetapir or florbetaben) and tau PET (flortaucipir) scans. The high/low tau threshold was the 90th percentile SUVr of Aβ‐ cognitively normal individuals for a composite flortaucipir region of interest spanning most of the medial/lateral temporal lobes and extratemporal neocortex relative to inferior cerebellar grey matter (Figure 1). We compared Aβ+ high vs low tau groups on AD/cerebrovascular biomarkers, and demographic, cognitive, risk factor, and clinical measurements.ResultOf 218 Aβ+ impaired ADNI patients, 91 (42%) had cortical tau in the normal range. Compared to their high tau counterparts, low tau individuals were more likely to be male, older, have more years of education, and lower Aβ (within the elevated/abnormal range), but did not differ on proportion of ApoE4 carriers. Low tau individuals were also more likely to have cardiovascular risk factors and cerebrovascular pathology, but had less severe hippocampal atrophy and temporoparietal hypometabolism and better cognitive performance than high tau individuals. Examination of baseline tau (Figure 2A) and longitudinal tau (Figure 2B) rankings across 70 FreeSurfer‐defined regions revealed a highly overlapping set of medial/lateral temporal regions common to both high/low groups.ConclusionFor impaired individuals on the AD pathway, low tau PET burden is associated with heterogeneous group characteristics that support a role for copathologies in accounting for cognitive symptoms, but also point to the less advanced stage of cognitive and biomarker progression in this group. Despite these striking group differences, the set of regions in which tau was highest in the brain was strikingly consistent between groups, suggesting a common spatial accumulation pattern regardless of the degree of tau burden.

The Content of Phosphorus in the Needles of Pinus sylvestris L. Affected by Industrial Air Pollution

A facility for disposal of toxic substances had been functioning in Kirov Oblast between 2006 and 2015. Destruction of phosphorus-containing substances resulted in formation of inorganic phosphorus compounds, which could enter the environment as components of gaseous emissions. The aim of the present work was to study the spatial patterns of accumulation of phosphorus compounds in the needles of Pinus sylvestris L. in the production area. The study was carried out at monitoring sites, which were represented by forest communities (southern taiga subzone) located at different distances from the pollution source (0.96–9.63 km). The total phosphorus in second-year pine needles was determined by the spectrophotometric method. During the research period (2011–2017), total phosphorus in the needles of P. sylvestris varied between 730 and 2229 μg/g. Based on results of cluster analysis, the sites were classified into two groups, which differed in levels of phosphorus accumulation in the needles of Р. sylvestris. The first group included sites with increased accumulation of total phosphorus in pine needles, which were located near the source of pollution in the direction of the prevailing winds. In sites belonging to the second group, the needles contained reduced amounts of phosphorus compounds. During the research period, variations in the amount of phosphorus in pine needles followed a similar pattern. From 2011 to 2016, the accumulation of phosphorus in the needles increased at monitoring sites of both groups. A decrease in total phosphorus in needles in 2017 was caused by a decrease in the release of phosphorus compounds to the environment and the involvement of accumulated phosphorus in the life processes of P. sylvestris. The increased accumulation of phosphorus compounds in needles in the sites near the source of air pollution was not favorable for vital processes of P. sylvestris needles and resulted in a reduction in their lifespan. Thus, the needles of P. sylvestris can be used as an accumulative indicator in areas affected by industrial air pollution by phosphorus compounds

Pattern-based downscaling of snowpack variability in the western United States

The decline in snowpack across the western United States is one of the most pressing threats posed by climate change to regional economies and livelihoods. Earth system models are important tools for exploring past and future snowpack variability, yet their coarse spatial resolutions distort local topography and bias spatial patterns of accumulation and ablation. Here, we explore pattern-based statistical downscaling for spatially-continuous interannual snowpack estimates. We find that a few leading patterns capture the majority of snowpack variability across the western US in observations, reanalyses, and free-running simulations. Pattern-based downscaling methods yield accurate, high resolution maps that correct mean and variance biases in domain-wide simulated snowpack. Methods that use large-scale patterns as both predictors and predictands perform better than those that do not and all are superior to an interpolation-based “delta change” approach. These findings suggest that pattern-based methods are appropriate for downscaling interannual snowpack variability and that using physically meaningful large-scale patterns is more important than the details of any particular downscaling method.

Long‐term accumulation of macro‐ and secondary elements in subtropical treatment wetlands

AbstractThe Everglades Stormwater Treatment Areas (STAs) are a complex of large constructed wetlands that are an integral component of the State and Federal efforts to restore the Everglades ecosystem. The overall objective of this study was to determine the accumulation rates of macro‐elements including carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and associated secondary elements including calcium (Ca), magnesium (Mg), aluminum (Al), and iron (Fe) in two Everglades STAs over their periods of operation. The study was conducted in STA‐2 with parallel flow‐ways consisting of emergent aquatic vegetation (EAV) and submerged aquatic vegetation (SAV) and the Western flow‐way of STA‐3/4 with EAV and SAV cells operated in series. Elemental accumulation rates were determined in the unconsolidated surficial sediments (floc) and recently accreted soil (RAS) that have accumulated on top of the antecedent soil over the 14‐ and 10‐yr periods of operation for STA‐2 and STA‐3/4, respectively. Flow‐ways with SAV were more efficient than EAV in accreting mineral matter, resulting in increased bulk density and higher accumulation rates of elements. Average C accumulation in the floc and RAS of SAV flow‐ways was 320 g·m−2·yr−1 with approximately equal proportions of inorganic and organic C, while in the EAV flow‐ways accumulation rates of C ranged from 116 to 147 g·m−2·yr−1 with mostly organic C. Phosphorus accumulation rates were approximately 2–3 times higher in SAV than in EAV flow‐ways. Differences in accumulation of elements between SAV and EAV were largest for Ca with 17–42 times more Ca in SAV than EAV systems. This suggests that in the SAV systems, possible occlusion of macro‐elements and metals during CaCO3 precipitation facilitated accretion of material with high mineral content. In EAV, biomass turnover and associated biotic processes regulated organic matter accumulation rates. The spatial accumulation patterns of P, C, and N in the EAV areas of STA‐2 and STA‐3/4 were similar to those observed in the EAV areas of the natural wetlands in Water Conservation Areas, suggesting that constructed wetland systems function similarly to natural wetlands dominated by EAV areas in retaining and storing macro‐ and secondary elements.

Filling Linnean shortfalls increases endemicity patterns: conservation and biogeographical implications for the extreme case ofLiolaemus(Liolaemidae, Squamata) species

AbstractLinnean shortfalls, or the discrepancy between formally described species and the number of existing species, imply noteworthy biodiversity conservation constraints. The case of Argentinian reptiles is unique in this context. The genus Liolaemus represents ~60% of the Argentine reptile fauna and has a current species description rate of 3.25 spp./year, leading to a significant increase in the number of known species. Filling Linnean shortfalls within this genus has revealed an extraordinary recent evolutionary radiation that strongly modifies the spatial accumulation patterns of richness and endemism, mainly in the Patagonian steppe and Monte ecoregions of Argentina. Thus, while 40 years ago none of the studied species was considered endemic at the ecoregional level, today the genus represents an essential element to define the southernmost terrestrial ecoregions of the world. Furthermore, the remarkable decrease in the average extent of occurrence (EOO) of Liolaemus species implies an increased extinction risk in light of threats caused by humans. Based on the thresholds for the IUCN Red List B1 criteria, and 11 well-studied clades of Liolaemus, we show that, while in 1980 87% of the described species would not qualify as threatened based on EOO, today 80% of the species have an EOO smaller than 20 000 km2. Therefore, they may qualify as threatened based on the B1 EOO thresholds, which demonstrates the importance of the recent increase of knowledge regarding the taxonomy, systematics and genetics of the group.

Smaller-scale land grabs and accumulation from below: Violence, coercion and consent in spatially uneven agrarian change in Shan State, Myanmar

Abstract This article presents field research data on a smallholder maize crop boom in Shan State, northern Myanmar, and its spatially uneven dispossessory effects. Local research teams studied eight villages, four in the north and an equal number in the south of Shan State, using focus group discussions and randomized household interviews, supplemented with key informant interviews. This study deepens the global land grab debate by highlighting the role of smallholder cash crop booms in “smaller-scale” land grabs that have been shown to be significant drivers of agrarian transformation, especially in Southeast Asia. The article builds on the conceptualization of “accumulation from below” by accounting for the geographically differentiated processes of dispossession from smallholder contract farming arrangements, its variant forms of coercion and consent, and the political contingencies that give rise to and help explain uneven agrarian change. The study’s findings demonstrate how political contingency shapes spatial patterns of accumulation and dispossession through regional and local variations in the politics of ethnic identity, migration, insurgency and an illicit drugs economy. These political dynamics inform the hierarchy of power and cultural familiarity between smallholders and local state-supported “silent strongmen”, in this case town moneylenders and village elites, which—together with several other identified factors, especially the poppy economy—influence the spatial distribution of dispossession. Neither extra-economic coercion within orbits of state power nor simply accumulation from below by market opportunities adequately explains uneven agrarian transformation. Instead, the analytical frame on forms of violence in capital accumulation should be expanded and deepened in order to better capture the complex coming together of violence, coercion and consent that is geographically specific, and taken together is more than the sum of their parts.

Spatial pattern of accumulation at Taylor Dome during Marine Isotope Stage 4: stratigraphic constraints from Taylor Glacier

Abstract. New ice cores retrieved from the Taylor Glacier (Antarctica) blue ice area contain ice and air spanning the Marine Isotope Stage (MIS) 5–4 transition, a period of global cooling and ice sheet expansion. We determine chronologies for the ice and air bubbles in the new ice cores by visually matching variations in gas- and ice-phase tracers to preexisting ice core records. The chronologies reveal an ice age–gas age difference (Δage) approaching 10 ka during MIS 4, implying very low snow accumulation in the Taylor Glacier accumulation zone. A revised chronology for the analogous section of the Taylor Dome ice core (84 to 55 ka), located to the south of the Taylor Glacier accumulation zone, shows that Δage did not exceed 3 ka. The difference in Δage between the two records during MIS 4 is similar in magnitude but opposite in direction to what is observed at the Last Glacial Maximum. This relationship implies that a spatial gradient in snow accumulation existed across the Taylor Dome region during MIS 4 that was oriented in the opposite direction of the accumulation gradient during the Last Glacial Maximum.

Holocene Ice‐Flow Speedup in the Vicinity of the South Pole

AbstractThe South Pole Ice Core (SPICEcore) was drilled at least 180 km from an ice‐flow divide. Thus, the annual‐equivalent layer thicknesses in the core are affected by spatial variations in accumulation upstream in addition to temporal variations in regional accumulation. We use a new method to compare the SPICEcore accumulation record, derived by correcting measured layer thicknesses for thinning, with an accumulation record derived from new GPS and radar measurements upstream. When ice speeds are modeled as increasing by 15% since 10 ka, the upstream accumulation explains 77% of the variance in the SPICEcore‐derived accumulation (versus 22% without speedup). This result demonstrates that the ice‐flow direction and spatial pattern of accumulation were stable throughout the Holocene. The 15% speedup in turn suggests a slight (3–4%) steepening or thickening of the ice‐sheet interior and provides a new constraint on the evolution of the East Antarctic Ice Sheet following the glacial termination.

Measles outbreak risk in Pakistan: exploring the potential of combining vaccination coverage and incidence data with novel data-streams to strengthen control.

Although measles incidence has reached historic lows in many parts of the world, the disease still causes substantial morbidity globally. Even where control programs have succeeded in driving measles locally extinct, unless vaccination coverage is maintained at extremely high levels, susceptible numbers may increase sufficiently to spark large outbreaks. Human mobility will drive potentially infectious contacts and interact with the landscape of susceptibility to determine the pattern of measles outbreaks. These interactions have proved difficult to characterise empirically. We explore the degree to which new sources of data combined with existing public health data can be used to evaluate the landscape of immunity and the role of spatial movement for measles introductions by retrospectively evaluating our ability to predict measles outbreaks in vaccinated populations. Using inferred spatial patterns of accumulation of susceptible individuals and travel data, we predicted the timing of epidemics in each district of Pakistan during a large measles outbreak in 2012-2013 with over 30 000 reported cases. We combined these data with mobility data extracted from over 40 million mobile phone subscribers during the same time frame in the country to quantify the role of connectivity in the spread of measles. We investigate how different approaches could contribute to targeting vaccination efforts to reach districts before outbreaks started. While some prediction was possible, accuracy was low and we discuss key uncertainties linked to existing data streams that impede such inference and detail what data might be necessary to robustly infer timing of epidemics.

Top-down Metabolomic Approaches for Nitrogen-Containing Metabolites.

Streamlining the processes that reveal heteroatom-containing metabolites and their biosynthetic genes is essential in integrated metabolomics studies. These metabolites are especially targeted for their potential pharmaceutical activities. By using a Fourier-transform ion cyclotron resonance-mass spectrometry (FTICR-MS) instrument, we provide top-down targeted metabolomic analyses using ultrahigh-resolution liquid chromatography-mass spectrometry (LC-MS), high-resolution matrix-assisted laser desorption/ionization (MALDI), and high-resolution imaging mass spectrometry (IMS) with 15N labeling of nitrogen-containing metabolites. In this study, we efficiently extract known and unknown chemicals and spatial information from the medicinal plant Catharanthus roseus, which sources several cancer drugs. The ultrahigh-resolution LC-MS analysis showed that the molecular formula of 65 N-metabolites were identified using the petals, peduncles, leaves, petioles, stems, and roots of the non- and 15N-labeled Catharanthus plants. The high resolution MALDI analysis showed the molecular formula of 64 N-metabolites using the petals, leaves, and stems of the non- and 15N-labeled Catharanthus. The chemical assignments using molecular formulas stored in databases identified known and unknown metabolites. The comparative analyses using the assigned metabolites revealed that most of the organ-specific ions are derived from unknown N-metabolites. The high-resolution IMS analysis characterized the spatial accumulation patterns of 32 N-metabolites using the buds, leaves, stems, and roots in Catharanthus. The comparative analysis using the non- and 15N-labeled IMS data showed the same spatial accumulation patterns of a non- and 15N-labeled metabolite in the organs, showing that top-down analysis can be performed even in IMS analysis.

Spatial accumulation pattern of citrulline and other nutrients in immature and mature watermelon fruits.

Watermelon (Citrullus lanatus L.) originates from arid regions of southern Africa, and its fruit contains a large amount of the amino acid citrulline, an efficient hydroxyl radical scavenger. Citrulline is implicated in the production of nitric oxide in human endothelium, and potential health benefits including vasodilatation and antioxidant functions have been suggested. However, citrulline metabolism in watermelon fruits is poorly understood. This study examined the accumulation pattern of citrulline and other nutrients in immature and mature watermelon fruits. In mature fruits, highest citrulline concentration was observed in the outer peel, followed by the central portion of the flesh and inner rinds, whereas the level was lower in the peripheral portion of the flesh. Citrulline content was generally low in immature fruits. Spatial and developmental patterns of citrulline accumulation were largely different from those of the antioxidant lycopene, total proteins, and soluble sugars such as glucose, fructose, and sucrose. Principal component analysis suggested a clear distinction of the central flesh and outer peels in mature fruits from other tissues in terms of the levels of major nutrients. These observations suggested that citrulline accumulation may be regulated in a distinct manner from other nutrients during watermelon fruit maturation. © 2016 Society of Chemical Industry.

Methionine and S-methylmethionine exhibit temporal and spatial accumulation patterns during the Arabidopsis life cycle.

Methionine is a nutritionally essential sulfur-containing amino acid found at low levels in plant tissues. Yet, the factors that regulate its synthesis and accumulation in seeds are not fully known. Recent genetic studies demonstrate that Arabidopsis seeds are able to synthesize methionine de novo through the aspartate family pathway similarly to vegetative tissues; however, additional biochemical studies suggest that the S-methylmethionine (SMM) cycle also plays a major role in methionine synthesis in seeds. To better understand the contribution of these two pathways to methionine synthesis, we have sampled various vegetative and reproductive tissues during the Arabidopsis life cycle and determined the contents of soluble and protein-incorporated methionine, SMM, as well as the expression levels of the key genes involved in these two pathways. Our results strengthen the hypothesis that SMM that is produced in the rosette leaves from methionine contributes to methionine accumulation in seeds. However, the SMM cycle may have additional functions in plant tissues since its key genes were expressed in all of the examined tissues, although at different rates. The accumulation patterns of soluble and protein-incorporated methionine during the Arabidopsis life cycle were found to be similar to most of the other amino acids, especially to those belonging to the branched-chain and aromatic amino acids that are produced in chloroplasts together with methionine. This indicates that similar factors regulate the levels of amino acids during development.

Natural and human impacts on centennial sediment accumulation patterns on the Umpqua River margin, Oregon

Abstract Quantifying patterns of sediment accumulation rates (SARs) over the past ~ 125 years on continental margins provides insight into diverse processes spanning the land–ocean boundary. In particular, temporal changes in the export of fluvial sediment can lead to changes in ocean margin SARs, whereas spatial patterns of accumulation reflect the net effect of wave-driven resuspension and current transport averaged over many years. To explore these issues we quantified SARs using 210 Pb geochronology at 73 stations on the shelf and upper slope off the Umpqua River, Oregon. Three types of 210 Pb profiles were observed: a well-defined roughly 10-cm-thick surface mixing layer (SML) underlain by a zone of logarithmic decrease on the distal mid to outer shelf and slope (type 1, n = 45); a deep (20–30-cm thick) SML underlain by a zone of logarithmic decrease in the sandy inner shelf (type 2, n = 8); and a composite profile with two distinct zones of logarithmic decrease below an ~ 10-cm-thick SML in a mid-shelf depocenter adjacent to the river mouth (type 3, n = 21). Type 3 profiles imply a 2–4-fold increase in the SAR that occurred, on average, in 1967 ± 13 y. Such an increase in SARs is consistent with the history of industrial logging in the Umpqua basin, which peaked in the two decades after World War II and coincided with a wet phase of the Pacific Decadal Oscillation (1944–1978) when average and peak river flows were elevated. Comparison of the Umpqua River shelf depocenter with the well-studied Columbia and Eel River systems reveals some important similarities and differences between these ‘marine-dispersal dominated’ systems, whereby forcing (e.g., river–ocean coherence) on the Umpqua is comparable to that of the Eel, whereas the spatial pattern is more similar to that of the Columbia. These seemingly paradoxical results can be reconciled by considering the relative significant wave height during periods of elevated sediment delivery.