Transition Zone Region Research Articles

Richness and endemism in Chusquea subg. Swallenochloa (Poaceae), a Neotropical subgenus adapted to temperate conditions

Chusquea subg. Swallenochloa comprises 52 species distributed in five biogeographical areas (Mexican Transition Zone, Brazilian subregion, South American Transition Zone, Chacoan subregion, and Andean region). Species of the subgenus grow from almost sea level in the Andean region to almost 4000 m in the northern South American Transition Zone (SATZ) and are often common or dominant elements of the vegetation. In this study, three questions related to species richness, endemism, and risk category of Chusquea subg. Swallenochloa were addressed. Analyses were based on the geo-referenced occurrence data of these 52 species, using different methods and software programs. Results indicate that the Chacoan subregion and SATZ had the highest richness with 16 and 15 species, respectively. The area of highest endemism was found in the Brazilian subregion. The AOO and EOO methods provided strongly differing estimations of conservation status.

Photosynthetic Rate and Root Growth Responses to Ascophyllum nodosum Extract–based Biostimulant in Creeping Bentgrass under Heat and Drought Stress

Creeping bentgrass (Agrostis stolonifera) experiences quality decline during summer in the United States transition zone and warmer regions. Various bioproducts have been used to improve creeping bentgrass performance and to mitigate effects of summer stress in the United States transition zone. This 2-year study was carried out to examine if foliar application of seaweed extract (SWE; Ascophyllum nodosum)-based biostimulant Utilize® could enhance creeping bentgrass nitrate reductase (NaR) activity, and root viability under heat and drought stress conditions. The Utilize® was sprayed biweekly on creeping bentgrass foliage at 0, 29, 58, 87, and 116 µL⋅m−2, with application volume of 815 L⋅ha−2. Two weeks after first application, plants were exposed to heat (35/25 °C, day/night) and drought stress (40% to 50% evapotranspiration replacement) conditions for 42 days in an environment-controlled growth chamber. In general, the abiotic stress caused turf quality reduction. Foliar application of Utilize® at 58, 87, and 116 µL⋅m−2 increased turf quality, leaf color ratings, leaf chlorophyll, carotenoid content, and net photosynthetic rate (Pn). Utilize® at 58, 87, and 116 µL⋅m−2 increased NaR activity by 26.5%, 16.3%, and 16.3%, respectively, when compared with the control. Utilize® at 58, 87, and 116 µL⋅m−2 increased root biomass, root length, surface area (SA), and root volume when compared with the control. Utilize® at 58 and 87 µL⋅m−2 improved root viability by 16.3% and 30.9%, respectively, when compared with the control. Our data indicate that the SWE-based biostimulant Utilize® improves nitrogen (N) metabolism and root viability. Utilize® treatment at 58 µL⋅m−2 biweekly can be considered an effective approach for improving creeping bentgrass performance during summer stress.

Simultaneous Improvement in Strength and Ductility of TC4 Matrix Composites Reinforced with Ti1400 Alloy and In Situ-Synthesized TiC

To overcome the tradeoff between strength and ductility of materials and obtain titanium matrix composites with excellent mechanical properties, in this study, the in situ-synthesized TiC particles and Ti-Al-V-Mo-Cr (Ti1400) alloy-reinforced Ti6Al4V (TC4) matrix composites ((Ti1400 + TiC)/TC4) were fabricated by low-energy ball milling and spark plasma sintering. The inhomogeneous distribution of TiC particles and Ti1400 alloy, as well as the compositional and structural transition zone, were characterized. The TiC/TC4 composite displayed a significantly higher yield strength and tensile strength compared to the TC4 alloy. However, the total elongation of the TiC/TC4 composite was only 57% of that in the TC4 alloy. In contrast, the (Ti1400 + TiC)/TC4 composites exhibited noticeably higher total elongation than the TiC/TC4 composite. Furthermore, the tensile strength of the composite increased with the increase in Ti1400 alloy content. The increase in strength can be attributed to solid solution strengthening and fine grain strengthening. The compositional and structural transition zone, formed by element diffusion, provided a better interface combination between the reinforcements and TC4 matrix. In the transition zone and Ti1400 region, a large number of α/β interfaces can effectively alleviate the stress concentration, and the increase in the β phase can bear more plastic deformation, which is conducive to improving the elongation of the composite. As a result, the (Ti1400 + TiC)/TC4 composites exhibited simultaneous improvements in strength and ductility.

Historical temperature variability in a representative high-latitude region in the monsoon-continental climate transition zone in China

Global warming has exacerbated the instability of the climate and has led to the frequent occurrence of extreme cold and warm events. The complex geography of the high-latitude region of China's monsoon-continental transition zone makes it extremely sensitive to climate response, understanding temperature changes over long periods of time is crucial to revealing trends in climate change trends. In this study, we constructed a standardized tree-ring width chronology of Korean spruce growing in this area from 1845 to 2016 and used it to analyzed the response of the radial growth of Korean spruce to climatic factors such as temperature and precipitation. The results show that the annual mean temperature was the dominant climatic factor affecting the growth of Korean spruce. Hence, we reconstructed the annual mean temperature series of this region spanning the past 172 years. The analysis results show that the study area experienced five warm periods and five cold periods in the past 172 years. Cold years were dominant before 1960s, while temperature continuously rose and changed drastically in the early twenty-first century. The reconstructed annual mean temperature series has variability cycles of 3a, 7a, 10–12a, 15–22a and 30–40a. The results of this reconstruction enrich the tree-ring database in the representative regions of the monsoon-continental climate transition zone in China and provide a reference for systematically understanding the climate change patterns in the representative regions of the transition zone.

Distribution, Regionalization, and Diversity of the dung beetle genus Phanaeus MacLeay (Coleoptera: Scarabaeidae) using Species Distribution Models

The genus Phanaeus is a well-known group whose taxonomy has been described multiple times. Its distribution was previously classified into 11 ecogeographic groups that are equivalent to areas of endemism. Here we use Species Distribution Models to describe species richness patterns. We measured beta-diversity and regionalized its distribution into one region and one transition zone, both with three dominions: Mexican Transition Zone (North American, Mexican, and Mesoamerican dominions) and Neotropical region (Pacific, Brazilian, and Atlantic Forest dominions). We also present a species checklist and updated the distribution maps for 73 of 81 species described so far that reflects all the taxonomical updates. We include a list of all the recorded locations (by country, state, and province), list the recorded habitats and biomes, and describe the modelled environmental conditions for each species.

Evaluation of the ITZ modification efficiency via aggregate surface coating with nano SiO2 (NS) and its influence on properties

In order to effectively refine the porous microstructure of interfacial transition zone (ITZ) region in cement-based materials, the nano SiO2 (NS) was introduced into the mixture via aggregate pre-immerging in NS suspension to directly regulate the formation of ITZ microstructure. For comparison, a corresponding content of NS was directly added to the mixture during the casting process. The macro mechanical properties and micro pore structures of the specimens with varying modification methods and NS contents were assessed. The ITZ microstructures (in terms of porosity distribution and nano mechanical properties) were quantitatively characterized via the combination of BSE-SEM and nano indentation techniques. The results demonstrate that both modification methods could refine the microstructure of the bulk paste and ITZ. The directing adding method can more effectively modify the microstructure of the bulk paste with certain NS dosage (no more than 3%). At higher dosage, due to the agglomeration of the NS, the difference between two methods was not obvious. For ITZ modification, the aggregate pre-immerging method has more profound effect, from the aspects of reducing the ITZ thickness and decreasing the porosity of region in the extreme vicinity of aggregate surface (0–10 µm).

In situ architecture of the ciliary base reveals the stepwise assembly of intraflagellar transport trains.

The cilium is an antenna-like organelle that performs numerous cellular functions, including motility, sensing, and signaling. The base of the cilium contains a selective barrier that regulates the entry of large intraflagellar transport (IFT) trains, which carry cargo proteins required for ciliary assembly and maintenance. However, the native architecture of the ciliary base and the process of IFT train assembly remain unresolved. In this work, we used in situ cryo-electron tomography to reveal native structures of the transition zone region and assembling IFT trains at the ciliary base in Chlamydomonas. We combined this direct cellular visualization with ultrastructure expansion microscopy to describe the front-to-back stepwise assembly of IFT trains: IFT-B forms the backbone, onto which bind IFT-A, dynein-1b, and finally kinesin-2 before entry into the cilium.

Aquaporin 4 is not present in normal porcine and human lamina cribrosa.

Aquaporin 4 is absent from astrocytes in the rodent optic nerve head, despite high expression in the retina and myelinated optic nerve. The purpose of this study was to quantify regional aquaporin channel expression in astrocytes of the porcine and human mouse optic nerve (ON). Ocular tissue sections were immunolabeled for aquaporins 1(AQP1), 4(AQP4), and 9(AQP9), myelin basic protein (MBP), glial fibrillary acidic protein (GFAP) and alpha-dystroglycan (αDG) for their presence in retina, lamina, myelin transition zone (MTZ, region just posterior to lamina) and myelinated ON (MON). Semi- quantification of AQP4 labeling & real-time quantitative PCR (qPCR) data were analyzed in retina and ON tissue. Porcine and control human eyes had abundant AQP4 in Müller cells, retinal astrocytes, and myelinated ON (MON), but minimal expression in the lamina cribrosa. AQP1 and AQP9 were present in retina, but not in the lamina. Immunolabeling of GFAP and αDG was similar in lamina, myelin transition zone (MTZ) and MON regions. Semi-quantitative AQP4 labeling was at background level in lamina, increasing in the MTZ, and highest in the MON (lamina vs MTZ, MON; p≤0.05, p≤0.01, respectively). Expression of AQP4 mRNA was minimal in lamina and substantial in MTZ and MON, while GFAP mRNA expression was uniform among the lamina, MTZ, and MON regions. Western blot assay showed AQP4 protein expression in the MON samples, but none was detected in the lamina tissue. The minimal presence of AQP4 in the lamina is a specific regional phenotype of astrocytes in the mammalian optic nerve head.

Detailed mechanical characterization of the transition zone: New insight into the integration between the annulus and nucleus of the intervertebral disc

The Nucleus Pulposus (NP) and Annulus Fibrous (AF) are two primary regions of the intervertebral disc (IVD). The interface between the AF and NP, where the gradual transition in structure and type of fibers are observed, is known as the Transition Zone (TZ). Recent structural studies have shown that the TZ contains organized fibers that appear to connect the NP to the AF. However, the mechanical characteristics of the TZ are yet to be explored. The current study aimed to investigate the mechanical properties of the TZ at the anterolateral (AL) and posterolateral (PL) regions in both radial and circumferential directions of loading using ovine IVDs (N = 28). Young's and toe moduli, maximum stress, failure strain, strain at maximum stress, and toughness were calculated mechanical parameters. The findings from this study revealed that the mechanical properties of the TZ, including young's modulus (p = 0.001), failure strain (p < 0.001), strain at maximum stress (p = 0.002), toughness (p = 0.027), and toe modulus (p = 0.005), were significantly lower for the PL compared to the AL region. Maximum stress was not significantly different between the PL and AL regions (p = 0.164). We found that maximum stress (p = 0.002), failure strain (p < 0.001), and toughness (p = 0.001) were significantly different in different loading directions. No significant differences for modulus (young's; p = 0.169 and toe; p = 0.352) and strain at maximum stress (p = 0.727) were found between the radial and circumferential loading directions. Statement of significanceTo date there has not been a study that has investigated the mechanical characterization of the annulus (AF)-nucleus (NP) interface (transition zone; TZ) in the intervertebral disc (IVD), nor is it known whether the posterolateral (PL) and anterolateral (AL) regions of the TZ exhibit different mechanical properties. Accordingly, the TZ mechanical properties have been rarely used in the development of computational IVD models and relevant tissue-engineered scaffolds. The current research reported the mechanical properties of the TZ region and revealed that its mechanical properties were significantly lower for the PL compared to the AL region. These new findings enhance our knowledge about the nature of AF-NP integration and may help to develop more realistic tissue-engineered or computational IVD models.

The role of spatial transcriptomic profiling to determine androgen receptor signaling and immune infiltration in prostate cancer

272 Background: Prostate cancer (PCa) in the transition zone (TZ) accounts for approximately 30% of disease and tends to present with higher PSAs with a lower risk of seminal vesicle invasion, extra-capsular extension, and risk of biochemical recurrence compared with peripheral zone (PZ) tumors. The underlying biological mechanism for these differences is poorly understood. Here, we performed spatial transcriptomic profiling to elucidate the molecular differences between TZ and PZ PCa. Methods: We identified three patients who underwent radical prostatectomy for PCa (one each with PZ only, TZ only, and both PZ and TZ tumors) and used the NanoString’s Digital Spatial Profiling (DSP) platform to quantify whole transcriptomic gene expression data (17,128 genes) in multiple regions of interest (ROI) per patient (42 cancer and 8 normal samples). Four morphology markers to facilitate ROI selection in both cancer and normal areas (SYTO13 for nucleus, PanCK for epithelium, SMA for stroma and CD45 for immune cells) were selected. Raw counts for 17,128 genes were imported to R v.4.1.0 for downstream data analyses. Counts were Q3 normalized and scaled (Z-score) to enable plotting of all genes on the same axes. Differential gene expression analysis using a linear model fit by empirical Bayes moderation, gene set enrichment analysis (GSEA) by cancer hallmarks, XCell gene sets for pathway enrichment and immune cell deconvolution using CIBERSORT was performed. Results: There were grade group (GG) 4 (n=10) and 5 (n=10) tumors in PZ and GG 3 (n=10), 4 (n=11) and 5 (n=1) cancers in TZ regions. We observed distinct gene expression profiles between PZ (n = 20) and TZ (n=22) tumors. Interestingly, androgen receptor (AR) signaling was significantly higher in TZ PCa ROIs compared to PZ ROIs in both GSEA (false discovery rate &lt; 5%) and the androgen subcomponent of the genomic prostate score (p&lt;0.001), regardless of grade, epithelial, stromal or immune component of the region. To standardize the comparison, CIBERSORT’s absolute immune signature scores were only computed for GG4 tumors and found to be significantly higher in PZ GG4 tumors compared to TZ GG4 tumors. Notably, CD4+ memory T cells were significantly higher in PZ GG4 regions compared to TZ GG4 tumor regions (p&lt;0.05). Conclusions: Here, we demonstrate distinct gene expression profiles of PZ and TZ PCa. Specifically, we observed higher AR signaling in TZ cancers and higher levels of immune infiltration on PZ cancers. This is in concordance with prior knowledge that TZ tumors may be associated with higher serum PSA and PZ tumors may be associated with inflammation. Further studies are needed to discern the biological and clinical significance of the different molecular features of PZ and TZ PCa.

IFT trains overcome an NPHP module barrier at the transition zone.

Cilia harbor diffusion barriers for soluble and membrane proteins within their proximal-most transition zone (TZ) region and employ an intraflagellar transport (IFT) system to form dynamic motile and signaling compartments. In this issue, De-Castro and colleagues (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202010178) uncover a long-suspected role for the TZ in gating IFT particles.

Autosegmentation of Prostate Zones and Cancer Regions from Biparametric Magnetic Resonance Images by Using Deep-Learning-Based Neural Networks.

The accuracy in diagnosing prostate cancer (PCa) has increased with the development of multiparametric magnetic resonance imaging (mpMRI). Biparametric magnetic resonance imaging (bpMRI) was found to have a diagnostic accuracy comparable to mpMRI in detecting PCa. However, prostate MRI assessment relies on human experts and specialized training with considerable inter-reader variability. Deep learning may be a more robust approach for prostate MRI assessment. Here we present a method for autosegmenting the prostate zone and cancer region by using SegNet, a deep convolution neural network (DCNN) model. We used PROSTATEx dataset to train the model and combined different sequences into three channels of a single image. For each subject, all slices that contained the transition zone (TZ), peripheral zone (PZ), and PCa region were selected. The datasets were produced using different combinations of images, including T2-weighted (T2W) images, diffusion-weighted images (DWI) and apparent diffusion coefficient (ADC) images. Among these groups, the T2W + DWI + ADC images exhibited the best performance with a dice similarity coefficient of 90.45% for the TZ, 70.04% for the PZ, and 52.73% for the PCa region. Image sequence analysis with a DCNN model has the potential to assist PCa diagnosis.

Phylogenetic evaluation of Bipolaris and Curvularia species collected from turfgrasses

AbstractThe dothideomycete genera Bipolaris and Curvularia are important pathogens of grasses (Poaceae) and can associate with host tissues without disease symptoms. Species of both genera are responsible for leaf spot epidemics that commonly occur on turfgrass throughout the United States transition zone and southern regions. Recent species typifications with DNA sequences have made a broad examination of Bipolaris and Curvularia species obtained from turfgrass possible. Isolates for analysis were obtained from culture collections or isolated from symptomatic turfgrass samples. Phylogenies based on ITS, GPD, and TEF gene sequences were constructed using maximum likelihood and Bayesian analyses and used to determine intraspecific and intrageneric relationships among Bipolaris and Curvularia species isolated from turfgrasses. Similar to previous studies, Bipolaris and Curvularia species formed separate, well‐supported clades. Morphological identifications of genera and species based on published host‐based keys often disagreed with molecular groupings. For example, C. hawaiiensis (= B. hawaiiensis) could not be differentiated from B. cynodontis while C. australiensis (= B. australiensis) could not be differentiated from C. spicifera (= B. spicifera). Additionally, phylogenies suggest B. coffeana and B. cynodontis are synonymous. However, the number of pseudosepta per conidium was the only consistent morphological character. The delineation of species causing leaf spot diseases of warm‐season turfgrasses should improve disease management decisions and help identify potential pathogens in asymptomatic tissues.

Polyamines and ethylene metabolism during cold acclimation in zoysiagrass (Zoysia Japonica Steud.)

Zoysiagrass (Zoysia japonica Steud.) is a warm-season turfgrass species well adapted for lawns and golf courses in transition zone and other regions with warm climates; however, it losses color and goes into dormancy in late fall and winter. The physiological mechanisms of cold acclimation (CA) have not been well understood. This growth chamber study was designed to investigate changes in leaf polyamines (PAs) and activities of selected enzymes, and ethylene production in response to CA. Leaf chlorophyll content and photosynthesis rate declined and cell membrane electrolyte leakage and malondialdehyde increased during CA. Putrescine (Put) and spermidine declined and then increased after 10 days during CA. Ethylene increases after 15 days of CA. Put biosynthesis enzymes (arginine decarboxylase, ADC, ornithine decarboxylase, ODC, s-adenosylmethionine decarboxylase), and diamine oxidases and polyamine oxidase activities increased in response to CA, except for ADC which increased after 10 days of CA. Accumulation of O2- and H2O2 in leaf tissue was observed during CA. These results suggest that PAs and ethylene are involved in CA in zoysiagrass.

The ultrastructural organization of elastic fibers at the interface of the nucleus and annulus of the intervertebral disk

There has been no study to describe the ultrastructural organization of elastic fibers at the interface of the nucleus pulposus and annulus fibrosus of the intervertebral disk (IVD), a region called the transition zone (TZ). A previously developed digestion technique was optimized to eliminate cells and non-elastin ECM components except for the elastic fibers from the anterolateral (AL) and posterolateral (PL) regions of the TZ in ovine IVDs. Not previously reported, the current study identified a complex elastic fiber network across the TZ for both AL and PL regions. In the AL region, this network consisted of major thick elastic fibers (≈ 1 µm) that were interconnected with delicate (< 200 nm) elastic fibers. While the same ultrastructural organization was observed in the PL region, interestingly the size of the elastic fibers was smaller (< 100 nm) compared to those that were located in the AL region. Quantitative analysis of the elastic fibers revealed significant differences in the size (p < 0.001) and the orientation of elastic fibers (p = 0.001) between the AL and PL regions, with a higher orientation and larger size of elastic fibers observed in the AL region. The gradual elimination of cells and non-elastin extracellular matrix components identified that elastic fibers in the TZ region in combination with the extracellular matrix created a honeycomb structure that was more compact at the AF interface compared to that located close to the NP. Three different symmetrically organized angles of rotation (0⁰ and ±90⁰) were detected for the honeycomb structure at both interfaces, and the structure was significantly orientated at the TZ-AF compared to the TZ-NP interface (p = 0.003).

Robust, 3-Dimensional Visualization of Human Colon Enteric Nervous System Without Tissue Sectioning

Small, 2-dimensional sections routinely used for human pathology analysis provide limited information about bowel innervation. We developed a technique to image human enteric nervous system (ENS) and other intramural cells in 3 dimensions. Using mouse and human colon tissues, we developed a method that combines tissue clearing, immunohistochemistry, confocal microscopy, and quantitative analysis of full-thickness bowel without sectioning to quantify ENS and other intramural cells in 3 dimensions. We provided 280 adult human colon confocal Z-stacks from persons without known bowel motility disorders. Most of our images were of myenteric ganglia, captured using a 20× objective lens. Full-thickness colon images, viewed with a 10× objective lens, were as large as 4× 5 mm2. Colon from 2 pediatric patients with Hirschsprung disease was used to show distal colon without enteric ganglia, as well as a transition zone and proximal pull-through resection margin where ENS was present. After testing a panel of antibodies with our method, we identified 16 antibodies that bind to molecules in neurons, glia, interstitial cells of Cajal, and muscularis macrophages. Quantitative analyses demonstrated myenteric plexus in 24.5% ± 2.4% of flattened colon Z-stack area. Myenteric ganglia occupied 34% ± 4% of myenteric plexus. Single myenteric ganglion volume averaged 3,527,678 ± 573,832 mm3 with 38,706 ± 5763 neuron/mm3 and 129,321 ± 25,356 glia/mm3. Images of large areas provided insight into why published values of ENS density vary up to 150-fold-ENS density varies greatly, across millimeters, so analyses of small numbers of thin sections from the same bowel region can produce varying results. Neuron subtype analysis revealed that approximately 56% of myenteric neurons stained with neuronal nitric oxide synthase antibody and approximately 33% of neurons produce and store acetylcholine. Transition zone regions from colon tissues of patients with Hirschsprung disease had ganglia in multiple layers and thick nerve fiber bundles without neurons. Submucosal neuron distribution varied among imaged colon regions. We developed a 3-dimensional imaging method for colon that provides more information about ENS structure than tissue sectioning. This approach could improve diagnosis for human bowel motility disorders and may be useful for other bowel diseases as well.

Danger-Associated Peptides Interact with PIN-Dependent Local Auxin Distribution to Inhibit Root Growth in Arabidopsis.

Plant elicitor peptides (Peps) are damage/danger-associated molecular patterns that are perceived by the receptor-like kinases, PEPR1 and PEPR2, to enhance innate immunity and to inhibit root growth in Arabidopsis (Arabidopsis thaliana). Here, we show that Arabidopsis Pep1 inhibits root growth in a PEPR2-dependent manner, which is accompanied by swelling epidermal and cortex cells and root hair formation in the transition zone (TZ). These Pep1-induced changes were mimicked by exogenous auxin application and were suppressed in the auxin perception mutants transport inhibitor response1 (tir1) and tir1 afb1 afb2 Pep1-induced auxin accumulation in the TZ region preceded cell expansion in roots. Because local auxin distribution depends on PIN-type auxin transporters, we examined Pep1-PEPR-induced root growth inhibition in several pin mutants and found that pin2 was highly sensitive but pin3 was less sensitive to Pep1. The pin2 pin3 double mutant was as sensitive to Pep1 treatment as wild-type plants. Pep1 reduced the abundance of PIN2 in the plasma membrane through activating endocytosis while increasing PIN3 expression in the TZ, leading to changes in local auxin distribution and inhibiting root growth. These results suggest that Pep-PEPR signaling undergoes crosstalk with auxin accumulation to control cell expansion and differentiation in roots during immune responses.

Low heat input gas metal arc welding for dissimilar metal weld overlays part III: hydrogen-assisted cracking susceptibility

Dissimilar metal weld overlays of nickel-base alloys on low-alloy steel components are commonly used in the oil and gas, petrochemical, and power generation industries to provide corrosion and oxidation resistance in a wide range of service environments and temperatures. Traditionally, dissimilar weld overlays are produced using cold or hot wire gas tungsten arc welding. This study aims to identify and evaluate potential advantages of low heat input gas metal arc welding processes over the conventional gas tungsten arc welding in the production of such overlays. Parts I and II of this publication series described characteristics of the heat-affected zone and the transition zone region of alloy 625 on grade 22 steel overlays. These results indicate a good resistance against hydrogen-assisted cracking, which is being verified within this third part of the publication series. To determine the hydrogen-assisted cracking susceptibility, welded samples are tested using the delayed hydrogen-assisted cracking test. Fractography is performed using scanning electron microscopy along with energy dispersive spectroscopy. The results confirm the suitability and efficiency of low heat input gas metal arc welding for dissimilar weld overlays. Variation of the postweld heat treatment procedure bears potential for improvement in this respect.

Role of eddies on intensity of oxygen minimum zone in the Bay of Bengal

One of the strongest oxygen minimum zones (OMZ) in the world oceans occurs in the Bay of Bengal (BoB) with no systematic trends in dissolved oxygen (DO) since past half a century. An evaluation is made here to examine the influence of cyclonic (CE) and anticyclonic eddies (ACE) on OMZ in the BoB. Cyclonic eddy (CE) injected nutrients to photic zone leading to increase in integrated Chl-a to upper 100 m compared to ACE and Transition zone (TZ) region resulting in decrease in DO in the OMZ. In contrast, increase in DO concentrations, by 3–4 times, was observed between 100 and 200 m depth in the ACE compared to TZ region associated with vertical and horizontal supply of DO. This study suggested that CE intensify OMZ through increase in organic matter production and its subsequent decomposition whereas ACEs ventilate DO and weaken the OMZ in the BoB.

Quantification of Total and Intracellular Sodium Concentration in Primary Prostate Cancer and Adjacent Normal Prostate Tissue With Magnetic Resonance Imaging.

The aim of this study was to measure the tissue sodium concentration (TSC) within tumors and normal prostate in prostate cancer patients, using prostatectomy as pathological criterion standard. Fifteen patients with biopsy-proven, magnetic resonance imaging (MRI) visible, intermediate- or high-risk prostate cancer underwent a dedicated research sodium MRI, before treatment with radical prostatectomy. All participants signed written informed consent for this institutional review board-approved prospective study. 3 T MRI acquired using a dedicated multinuclear clamshell transmit coil and a bespoke dual-tuned H/Na endorectal receive coil, with intracellular-sodium imaging acquired using inversion recovery sequences; a phantom-based calibration enabled quantitative sodium maps. Regions of interest were defined for normal peripheral zone (PZ) and transition zone (TZ) and tumor regions, referenced from histopathology maps. A 1-way analysis of variance compared normal and tumor tissue, using Tukey test for multiple comparisons. Two patients were excluded due to artifact; software error resulted in 1 further intracellular-sodium failure. Fifteen tumors were detected (13 PZ, 2 TZ) in 13 patients: Gleason 3 + 3 (n = 1), 3 + 4 (6), 3 + 5 (2), 4 + 3 (5), 4 + 5 (1). Both mean TSC and intracellular-sodium were significantly higher in normal PZ (39.2 and 17.5 mmol/L, respectively) versus normal TZ (32.9 and 14.7; P < 0.001 and P = 0.02). Mean TSC in PZ tumor (45.0 mmol/L) was significantly higher than both normal PZ and TZ tissue (P < 0.001). Intracellular sodium in PZ tumors (19.9 mmol/L) was significantly higher than normal TZ (P < 0.001) but not normal PZ (P = 0.05). Mean TSC and intracellular-sodium was lower in Gleason ≤3 + 4 tumors (44.4 and 19.5 mmol/L, respectively) versus ≥4 + 3 (45.6 and 20.2), but this was not significant (P = 0.19 and P = 0.29). Tissue sodium concentration and intracellular sodium concentrations of prostate tumors were quantified, with PZ tumors demonstrating a significantly increased TSC.