Changes In Nutrient Status Research Articles

MTORC1-CTLH E3 ligase regulates the degradation of HMG-CoA synthase 1 through the Pro/N-degron pathway

Mammalian target of rapamycin (mTOR) senses changes in nutrient status and stimulates the autophagic process to recycle amino acids. However, the impact of nutrient stress on protein degradation beyond autophagic turnover is incompletely understood. We report that several metabolic enzymes are proteasomal targets regulated by mTOR activity based on comparative proteome degradation analysis. In particular, 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A (CoA) synthase 1 (HMGCS1), the initial enzyme in the mevalonate pathway, exhibits the most significant half-life adaptation. Degradation of HMGCS1 is regulated by the C-terminal to LisH (CTLH) E3 ligase through the Pro/N-degron motif. HMGCS1 is ubiquitylated on two C-terminal lysines during mTORC1 inhibition, and efficient degradation of HMGCS1 in cells requires a muskelin adaptor. Importantly, modulating HMGCS1 abundance has a dose-dependent impact on cell proliferation, which is restored by adding a mevalonate intermediate. Overall, our unbiased degradomics study provides new insights into mTORC1 function in cellular metabolism: mTORC1 regulates the stability of limiting metabolic enzymes through the ubiquitin system.

Nutrient status changes bacterial interactions in a synthetic community.

Microbial interactions affect community stability and niche spaces in all ecosystems. However, it is not clear what factors influence these interactions, leading to changes in species fitness and ecological niches. Here, we utilized 16 monocultures and their corresponding pairwise co-cultures to measure niche changes among 16 cultivable bacterial species in a wide range of carbon sources, and we used resource availability as a parameter to alter the interactions of the synthetic bacterial community. Our results suggest that metabolic similarity drives niche deformation between bacterial species. We further found that resource limitation resulted in increased microbial inhibition and more negative interactions. At high resource availability, bacteria exhibited little inhibitory potential and stronger facilitation (in 71% of cases), promoting niche expansion. Overall, our results show that metabolic similarity induces different degrees of resource competition, altering pairwise interactions within the synthetic community and potentially modulating bacterial niches. This framework may lay the basis for understanding complex niche deformation and microbial interactions as modulated by metabolic similarity and resource availability.IMPORTANCEUnderstanding the intricate dynamics of microbial interactions is crucial for unraveling the stability and ecological roles of diverse ecosystems. However, the factors driving these interactions, leading to shifts in species fitness and ecological niches, remain inadequately explored. We demonstrate that metabolic similarity serves as a key driver of niche deformation between bacterial species. Resource availability emerges as a pivotal parameter, affecting interactions within the community. Our findings reveal heightened microbial inhibition and more negative interactions under resource-limited conditions. The prevalent facilitation is observed under conditions of high resource availability, underscoring the potential for niche expansion in such contexts. These findings emphasize that metabolic similarity induces varying degrees of resource competition, thereby altering pairwise interactions within the synthetic community and potentially modulating bacterial niches. Our workflow has broad implications for understanding the roles of metabolic similarity and resource availability in microbial interactions and for designing synthetic microbial communities.

Sediment records from Lake Nipissing (ON, Canada) register a lake-wide multi-trophic response to climate change and reveal its possible role for increased cyanobacterial blooms

Recurring cyanobacterial blooms have been reported in Lake Nipissing (Ontario, Canada) since at least 2000. However, monitoring data indicate that surface water nutrient concentrations have not increased over the past ∼45 years in this large, shallow, mesotrophic lake. Applying paleolimnological methods, we establish baseline environmental conditions and extend the Lake Nipissing water quality data to pre-industrial times. Lake-wide assessment of changes in nutrient status, algal production, and effects of climate warming are provided by examining: 1) modern and pre-industrial sedimentary diatom assemblages from nine locations; 2) temporal trends in sedimentary photosynthetic pigments over ∼200 years from five locations; and 3) detailed sedimentary profiles of diatom and chironomid assemblage composition from Callander Bay, spanning the past ∼200 years. A pronounced shift in diatom assemblage composition was registered at all sites with pre-industrial sediments dominated by Aulacoseira spp. and modern samples dominated by Discostella stelligera. The detailed diatom analysis for Callander Bay indicated that this shift occurred ca. 1990. Since ca. 1975, cyanobacterial production (spectrally inferred from sediments) exceeded the ∼200-year mean and matches the observed increase in bloom reports. Twentieth century shifts in chironomid assemblages in Callander Bay from Procladius to Chironomus spp. dominance indicate lower hypolimnetic oxygen in recent decades. Collectively, these changes suggest that previously polymictic Lake Nipissing is now experiencing periods of thermal stratification and development of transient anoxia in bottom waters. These conditions are more prevalent and widespread in modern Lake Nipissing, consistent with a response to recent warming, decreased wind speed, and a longer ice-free period.

Estimation of water quality variables based on machine learning model and cluster analysis-based empirical model using multi-source remote sensing data in inland reservoirs, South China

Reservoirs play important roles in the drinking water supply for urban residents, agricultural water provision, and the maintenance of ecosystem health. Satellite optical remote sensing of water quality variables in medium and micro-sized inland waters under oligotrophic and mesotrophic status is challenging in terms of the spatio-temporal resolution, weather conditions and frequent nutrient status changes in reservoirs, etc., especially when quantifying non-optically active components (non-OACs). This study was based on the surface reflectance products of unmanned aerial vehicle (UAV) multispectral images, Sentinel-2B Multispectral instrument (MSI) images and Landsat 7 Enhanced Thematic Mapper Plus (ETM+) by utilizing fuzzy C-means (FCM) clustering algorithm was combined with band combination (BC) model to construct the FCM-BC empirical model, and used mixed density network (MDN), extreme gradient boosting (XGBoost), deep neural network (DNN) and support vector regression (SVR) machine learning (ML) models to invert 12 kinds of optically active components (OACs) and non-OACs. Compared with the unclustered BC (UC) model, the mean coefficient of determination (MR) of the FCM-BC models was improved by at least 46.9%. MDN model showed best accuracy (R2 in the range of 0.60–0.98) and stability (R2 decreased by up to 13.2%). The accuracy of UAV was relatively higher in both empirical methods and machine learning methods. Additionally, the spatio-temporal distribution maps of four water quality variables were mapped based on the MDN model and UAV images, all platforms showed good consistency. An inversion strategy of water quality variables in various monitoring frequencies and weather conditions were proposed finally. The purpose of introducing the UAV platform was to cooperate with the satellite to improve the monitoring response ability of OACs and non-OACs in small and micro-sized oligotrophic and mesotrophic water bodies.

Feature extraction using multi-view video analytics for dairy cattle body weight estimation

Accurate body weight (BW) estimation of livestock provides valuable information about animal health and welfare and can be used to assess changes in nutrient status of individuals or groups of animals. To obtain BW information regularly, automated low-cost methods that do not intrude upon normal farm operation are essential. Measurements of BW from 196 lactating, Holstein dairy cattle were collected across 5 days (655 +/- 77.1 kg; range 458 - 876 kg). This population of animals was used to develop a BW estimation system for dairy cattle using a synchronized two-camera system. The system applies deep-learning models and domain knowledge to both camera views to estimate BW of dairy cattle despite challenges such as occluding fences and crowded backgrounds. Videos from side and front-view were used to extract features about the anatomical locations and shape of the individual cows, and a regression model was applied to the features for BW prediction. We demonstrate that each view provides valuable information for BW estimation, where combining two views outperforms either view separately. This is despite the side view having distractors such as occluding fences and crowded backgrounds. The experimental results, applied to videos captured within the constraints of an operating dairy farm, demonstrate a root-mean-squared prediction error of 34 kg and a mean absolute percentage error of 4.1%, when a Random Forest is trained on four days of data and tested on the fifth unseen day. This model enabled 57% of cattle BW to be estimated within 25 kg of their measured BW. In addition, we demonstrated that linear regression generalized well to unseen data.

Tracking Soil Health Changes in a Management-Intensive Grazing Agroecosystem

Management-intensive Grazing (MiG) has been proposed to sustainably intensify agroecosystems through careful management of livestock rotations on pastureland. However, there is little research on the soil health impacts of transitioning from irrigated cropland to irrigated MiG pasture with continuous livestock rotation. We analyzed ten soil health indicators using the Soil Management Assessment Framework (SMAF) to identify changes in nutrient status and soil physical, biological, and chemical health five to six years after converting irrigated cropland to irrigated pastureland under MiG. Significant improvements in biological soil health indicators and significant degradation in bulk density, a physical soil health indicator, were observed. Removal of tillage and increased organic matter inputs may have led to increases in β-glucosidase, microbial biomass carbon, and potentially mineralizable nitrogen, all of which are biological indicators of soil health. Conversely, trampling by grazing cattle has led to increased bulk density and, thus, a reduction in soil physical health. Nutrient status was relatively stable, with combined manure and fertilizer inputs leading to stabilized plant-available phosphorous (P) and increased potassium (K) soil concentrations. Although mixed effects on soil health were present, overall soil health did increase, and the MiG system appeared to have greater overall soil health as compared to results generated four to five years earlier. When utilizing MiG in irrigated pastures, balancing the deleterious effects of soil compaction with grazing needs to be considered to maintain long-term soil health.

Extraradical hyphae exhibit more plastic nutrient-acquisition strategies than roots under nitrogen enrichment in ectomycorrhiza-dominated forests.

Ectomycorrhizal (ECM) functional traits related to nutrient acquisition are impacted by nitrogen (N) deposition. However, less is known about whether these nutrient-acquisition traits associated with roots and hyphae differentially respond to increased N deposition in ECM-dominated forests with different initial N status. We conducted a chronic N addition experiment (25 kg N ha-1 year-1 ) in two ECM-dominated forests with contrasting initial N status, that is, a Pinus armandii forest (with relatively low N availability) and a Picea asperata forest (with relatively high N availability), to assess nutrient-mining and nutrient-foraging strategies associated with roots and hyphae under N addition. We show that nutrient-acquisition strategies of roots and hyphae differently respond to increased N addition. Root nutrient-acquisition strategies showed a consistent response to N addition, regardless of initial forest nutrient status, shifting from organic N mining toward inorganic N foraging. In contrast, the hyphal nutrient-acquisition strategy showed diverse responses to N addition depending on initial forest N status. In the Pinus armandii forest, trees increased belowground carbon (C) allocation to ECM fungi thus enhancing hyphal N-mining capacity under increased N availability. By comparison, in the Picea asperata forest, ECM fungi enhanced both capacities of P foraging and P mining in response to N-induced P limitation. In conclusion, our results demonstrate that ECM fungal hyphae exhibit greater plasticity in nutrient-mining and nutrient-foraging strategies than roots do in response to changes of nutrient status induced by N deposition. This study highlights the importance of ECM associations in tree acclimation and forest function stability under changing environments.

Fossil Diatoms Reveal Natural and Anthropogenic History of Jackson Lake (Wyoming, USA)

Jackson Lake supplies valuable cultural and provisioning ecosystem services to the Upper Snake River watershed in Wyoming and Idaho (western USA). Construction of Jackson Lake Dam in the early 20th century raised lake level by ∼12 m, generating an important water resource supporting agriculture and ranching, as well as tourism associated with Grand Teton National Park. Outlet engineering drastically altered Jackson Lake’s surface area, morphology, and relationship with the inflowing Snake River, yet the consequences for nutrient dynamics and algae in the lake are unknown. Here, we report the results of a retrospective environmental assessment completed for Jackson Lake using a paleolimnological approach. Paleoecological (diatoms) and geochemical datasets were developed on a well-dated sediment core and compared with available hydroclimate data from the region, to assess patterns of limnological change. The core spans the termination of the Little Ice Age and extends to the present day (∼1654–2019 CE). Diatom assemblages prior to dam installation are characterized by high relative abundances of plankton that thrive under low nutrient availability, most likely resulting from prolonged seasonal ice cover and perhaps a single, short episode of deep convective mixing. Following dam construction, diatom assemblages shifted to planktic species that favor more nutrient-rich waters. Elemental abundances of sedimentary nitrogen and phosphorous support the interpretation that dam installation resulted in a more mesotrophic state in Jackson Lake after ∼1916 CE. The data are consistent with enhanced nutrient loading associated with dam emplacement, which inundated deltaic wetlands and nearshore vegetation, and perhaps increased water residence times. The results of the study highlight the sensitivity of algal composition and productivity to changes in nutrient status that accompany outlet engineering of natural lakes by humans and have implications for water resource management.

Influence of different organic amendments in modulation of soil physico-chemical characteristics and growth of marigold seedlings

Organic farming has emerged as a sustainable approach for increasing crop production while maintaining soil fertility. This eco-friendly practice relies on the use of various living microbes such as Rhizobia, arbuscular mycorrhiza fungi (AMF) and partially or fully decomposed biological materials like manure, compost, litter, coir, moss, and similar products used as soil supplements and/or conditioners for augmenting soil fertility. The present study was designed to evaluate the effect of these amendments on soil physico-chemical characteristics, and on germination and growth of marigold (Tagetes erecta) seedlings raised on these soils. The experiment was carried out in pots filled with garden soil amended with compost, moss, coir and NPK while un-amended garden soil served as control. Analysis of soil samples with organic materials show a slight change toward basic pH while inorganic fertilizer made the soil acidic. All the amendments led to increase in electrical conductivity while modulation of soil texture resulted in change in percolation rate. Amendments also resulted in changes in the soil nutrient content (organic C, N, P, K, Mg, Cu and Zn). However, coir and moss amendments did not bring about much change in nutrient status of the soil. There were notable changes in growth of marigold expressed in increased fresh weight, root length, shoot length as well number of nodes and number of leaves in amended soils. The study indicates that though coir and moss did not bring much change in nutrient status of soil but they altered the particle size for improved percolation.

Effect of Dam Emplacement and Water Level Changes on Sublacustrine Geomorphology and Recent Sedimentation in Jackson Lake, Grand Teton National Park (Wyoming, United States)

Dam installation on a deep hydrologically open lake provides the experimental framework necessary to study the influence of outlet engineering and changing base levels on limnogeological processes. Here, high-resolution seismic reflection profiles, sediment cores, and historical water level elevation datasets were employed to assess the recent depositional history of Jackson Lake, a dammed glacial lake located adjacent to the Teton fault in western Wyoming (USA). Prograding clinoforms imaged in the shallow stratigraphy indicate a recent lake-wide episode of delta abandonment. Submerged ∼11–12 m below the lake surface, these Gilbert-type paleo-deltas represent extensive submerged coarse-grained deposits along the axial and lateral margins of Jackson Lake that resulted from shoreline transgression following dam construction in the early 20th century. Other paleo-lake margin environments, including delta plain, shoreline, and glacial (drumlins, moraines) landforms were likewise inundated following dam installation, and now form prominent features on the lake floor. In deepwater, a detailed chronology was established using137Cs,210Pb, and reservoir-corrected14C for a sediment core that spans ∼1654–2019 Common Era (CE). Dam emplacement (1908–1916 CE) correlates with a nearly five-fold acceleration in accumulation rates and a depositional shift towards carbonaceous sediments. Interbedded organic-rich black diatomaceous oozes and tan silts track changes in reservoir water level elevation, which oscillated in response to regional climate and downstream water needs between 1908 and 2019 CE. Chemostratigraphic patterns of carbon, phosphorus, and sulfur are consistent with a change in nutrient status and productivity, controlled initially by transgression-driven flooding of supralittoral soils and vegetation, and subsequently with water level changes. A thin gravity flow deposit punctuates the deepwater strata and provides a benchmark for turbidite characterization driven by hydroclimate change. Because the Teton fault is a major seismic hazard, end-member characterization of turbidites is a critical first step for accurate discrimination of mass transport deposits controlled by earthquakes in more ancient Jackson Lake strata. Results from this study illustrate the influence of dam installation on sublacustrine geomorphology and sedimentation, which has implications for lake management and ecosystem services. Further, this study demonstrates that Jackson Lake contains an expanded, untapped sedimentary archive recording environmental changes in the American West.

Functional, not Taxonomic, Composition of Soil Fungi Reestablishes to Pre-mining Initial State After 52 Years of Recultivation

Open-cast mining leads to the loss of naturally developed soils and their ecosystem functions and services. Soil restoration after mining aims to restore the agricultural productivity in which the functions of the fungal community play a crucial role. Whether fungi reach a comparable functional state as in the soil before mining within half a century of recultivation is still unanswered. Here, we characterised the soil fungal community using ITS amplicon Illumina sequencing across a 52-year chronosequence of agricultural recultivation after open-cast mining in northern Europe. Both taxonomic and functional community composition showed profound shifts over time, which could be attributed to the changes in nutrient status, especially phosphorus availability. However, taxonomic composition did not reach the pre-mining state, whereas functional composition did. Importantly, we identified a positive development of arbuscular mycorrhizal root fungal symbionts after the initial three years of alfalfa cultivation, followed by a decline after conversion to conventional farming, with arbuscular mycorrhizal fungi being replaced by soil saprobes. We conclude that appropriate agricultural management can steer the fungal community to its functional pre-mining state despite stochasticity in the reestablishment of soil fungal communities. Nonetheless, conventional agricultural management results in the loss of plant symbionts, favouring non-symbiotic fungi.

Feasibility and Effectiveness of a Multi-Micronutrient Intervention as a Palliative Care Therapy in Patients With Congestive Heart Failure

ObjectivesVeterans with HF are at risk of micronutrient depletion due to combined systemic disease and drug induced altered nutrient disposition. This pilot aimed to test feasibility and effectiveness of a MMI to improve micronutrient status, cardiac function and quality of life in Veterans with HF. MethodsA pre/post repeated measures design was used. Veterans with stable HF stage B-D, left ventricular ejection fraction (LVEF) ≤45%, from ischemic cardiomyopathy with systolic dysfunction were recruited. The 6-month MMI was 3 tabs daily providing thiamin (B1) 100 mg, 50 mg each of riboflavin, niacin, pantothenic acid, pyridoxine (B6), inositol, 25 mg phosphatidyl choline, 400 mcg folic acid, and 50 mcg each of B12 and biotin, and 50 mg elemental zinc (Zn). Ergocalciferol was given as 50,000 IU weekly for 2 months then every 2 weeks for 4 months. Micronutrient status and LVEF (echocardiogram) were determined as least-squares mean (± standard error, SE) estimated from general linear mixed effect models fitted to micronutrient measurements adjusting for age (18–65 Vs. > 65); feasibility of MMI assessed as % consumed. ResultsThis abstract focuses on the nutrient status at baseline, feasibility of the MMI, and change in nutrient status following MMI. Twenty-two male Veterans (86% Caucasian), median 64 years (59–75 interquartile range, IQR) started MMI; 20 completed. At baseline, median (IQR) dietary intake was 1639 (1472–1838) calories, 36 (28–41) % fat, 13 (10–15) % saturated fat, 2981 (2067–3534) mg sodium while following the American Heart Association diet with 2 gm sodium restriction. Micronutrient intake was 1.2 (0.9–1.4) mg B1, 1.2 (1.0–1.8) mg B6, 49 (38–166) IU Vitamin D, and 7 (5–10) mg zinc. Median % compliance with MMI at 3 and 6 months was ≥ 92 and ≥94, respectively. Baseline and changes in blood measures of micronutrients were: B1, 119 (SE 13) and 96 (SE 20, p< 0.0001) nmol/L; B6, 11.4 (SE 6.3) and 57.3 (SE 9.2, p< 0.0001) ng/mL; total 25-OH Vitamin D, 31.2 (SE 2.3) and 6.5 (SE 3.4, p = 0.057) ng/mL; Zn, 81.4 (SE 5.1) and 13.8 (7.6, p = 0.07) mcg/dL. LVEF at baseline and 6 months were 28.9 (SE 1.6) % and 30.0 (SE 1.7) %, respectively (p = 0.64). ConclusionsThe feasibility of adding MMI to complex pharmaceutical regimens in male Veterans with stable HF was high. MMI was effective in improving micronutrient status and preserved LVEF. Funding SourcesDepartment of Veterans Affairs

Invasive earthworms Amynthas tokioensis and Amynthas agrestis alter macronutrients (Ca, Mg, K, P) in field and laboratory forest soils

Pheretimoid earthworms of the family Megascolecidae are invading deciduous forests across the northern and northeastern United States with unknown consequences on soil and nutrient dynamics. This study investigated plant macronutrients (Ca, Mg, K, and P) at partially invaded forest sites in Madison, WI, USA, and in forest soil incubated with Amynthas agrestis or Amynthas tokioensis. Exchangeable, organic-bound, and/or inorganic Ca, Mg, K, and P concentrations and pools were typically greater inside than outside the invasion front. Exchangeable K and organic K were significantly increased by Amynthas earthworms. These changes in nutrient status were associated with an increased pH and greater soil organic matter (SOM), suggesting litter decomposition by Amynthas was likely responsible for nutrient additions. Under laboratory soil incubations, increases in Ca, Mg, K, and P occurred for A. tokioensis but this was less consistent for A. agrestis. Soil incubations also demonstrated that A. tokioensis stabilized more nutrients and SOM than A. agrestis despite being fed one-third less oak litter. Thus, while Amynthas earthworms alter forest soils due to differences in feeding, digestion, and mineralization among species, whether these differences facilitate co-invasion or bring about long-term changes in ecosystem soil pools remains unclear.

Hepatokines and Non-Alcoholic Fatty Liver Disease: Linking Liver Pathophysiology to Metabolism.

The liver plays a key role in maintaining energy homeostasis by sensing and responding to changes in nutrient status under various metabolic conditions. Recently highlighted as a major endocrine organ, the contribution of the liver to systemic glucose and lipid metabolism is primarily attributed to signaling crosstalk between multiple organs via hepatic hormones, cytokines, and hepatokines. Hepatokines are hormone-like proteins secreted by hepatocytes, and a number of these have been associated with extra-hepatic metabolic regulation. Mounting evidence has revealed that the secretory profiles of hepatokines are significantly altered in non-alcoholic fatty liver disease (NAFLD), the most common hepatic manifestation, which frequently precedes other metabolic disorders, including insulin resistance and type 2 diabetes. Therefore, deciphering the mechanism of hepatokine-mediated inter-organ communication is essential for understanding the complex metabolic network between tissues, as well as for the identification of novel diagnostic and/or therapeutic targets in metabolic disease. In this review, we describe the hepatokine-driven inter-organ crosstalk in the context of liver pathophysiology, with a particular focus on NAFLD progression. Moreover, we summarize key hepatokines and their molecular mechanisms of metabolic control in non-hepatic tissues, discussing their potential as novel biomarkers and therapeutic targets in the treatment of metabolic diseases.

In situ monitoring of chlorophyll a fluorescence in Nannochloropsis oceanica cultures to assess photochemical changes and the onset of lipid accumulation during nitrogen deprivation.

In situ chlorophyll a fluorescence measurements were applied to monitor changes in the photochemical variables of Nannochloropsis oceanica cultures under nitrogen-deplete and nitrogen-replete (control) conditions. In addition, growth, lipid, fatty acid, and pigment contents were also followed. In the control culture, growth was promoted along with pigment content, electron transport rate (ETR), and polyunsaturated fatty acids, while total lipid content and fatty acid saturation level diminished. Under nitrogen-deplete conditions, the culture showed a higher de-epoxidation state of the xanthophyll cycle pigments. Fast transients revealed a poor processing efficiency for electron transfer beyond QA , which was in line with the low ETR due to nitrogen depletion. Lipid content and the de-epoxidation state were the first biochemical variables triggered by the change in nutrient status, which coincided with a 20% drop in the in situ effective quantum yield of PSII (ΔF'/Fm '), and a raise in the Vj measurements. A good correlation was found between the changes in ΔF'/Fm ' and lipid content (r = -0.96, p < 0.01). The results confirm the reliability and applicability of in situ fluorescence measurements to monitor lipid induction in N. oceanica.

Incursion of Alaska Coastal Water as a mechanism promoting small phytoplankton in the western Arctic Ocean

The inflow of Alaska Coastal Water (ACW) acts as a source of heat and freshwater for the Arctic Ocean, and contributes to ecosystem succession as well as phytoplankton change. To explore the mechanisms and patterns of the phytoplankton composition in response to the ACW, diagnostic pigments and environmental parameters were analyzed along three similar transects from shelf to basin in the Arctic Ocean during summer in 2008–2016. The results showed that the incursion of the ACW reduced the chlorophyll a (Chl a) concentration in the shelf areas, but favored phytoplankton growth in basin areas, especially that of small prasinophytes and chrysophytes. A possible explanation is the change in nutrient status, because during its northward flow, the ACW dissipates heat and receives nutrients from the surrounding cold water. The concentrations of Prasino and Chl b (the diagnostic pigments of prasinophytes) increase from barely detected in 2008 to higher than 15 ng/dm3 (Prasino) and 65 ng/dm3 (Chl b) respectively in 2014 and 2016, which occurred synchronously with presence of ACW and an increase in subsurface nitrate reservoirs. These findings indicate that the incursion of the ACW brings nutrients into subsurface basin layers, which could favor the growth of small phytoplankton in the western Arctic Ocean.

Performance of &lt;i&gt;Anthocephalus cadamba&lt;/i&gt; (Roxb.) Miq., &lt;i&gt;Bauhinia variegata&lt;/i&gt; Linn. and &lt;i&gt;Grewia optiva&lt;/i&gt; Drumm. Ex Burr in Tarai Bhabar region of Uttarakhand, India

Baljit Singh, R.i.s. Gill, Navneet Kaur And G.p.s. DhillonThe study was carried out on farmer's rainfed land in Dhaluwala majbata and Dhaluwala Kalan in Haridwar district of Uttarakhand in 2018-2020. Block planting of 6 month old seedling of Anthocephalus cadamba, Bauhinia variegata and Grewia optiva was done in 2 treatments of spacing i.e. 6 × 6 m and 6 × 8 m. On observation, it was found that A. cadamba stood first in spacing of 6 × 8 m with a height of 300.67 cm and girth 19.18 cm followed by G. optiva of height 292.45 cm and B. variegata of height 285.67 but in girth performance B. variegata i.e. 17.0 cm was found better than G. optiva i.e. 15.72 cm. On the basis of observations, it can be asserted that A. cadamba is a fast growing timber species and may be suitable species under agroforestry in sub tropics of Uttarakhand while B. variegata are slow growing but they are known as fodder species and may be grown as fodder species on a farmland. The study on soil property showed that pH of soil ranges from 6.47 to 7.47 i.e. slightly acidic to slightly alkaline and no remarkable changes in nutrient status were recorded.

TiO2 nanoparticles enhanced bioaccumulation and toxic performance of PAHs via trophic transfer

Engineering nanoparticles (NPs) could act as accumulator and carrier of co-contaminants, affecting their fate and toxicity in environments. However, the effects of NPs on the bioaccumulation and trophic transfer of co-contaminants through the food chain and the ensuing effects on higher predators are unclear. In the present study, we investigated the effects of titanium dioxide nanoparticles (nTiO2) on the trophic transfer of phenanthrene (Phe) from prey Artemia salina to predator Scophthalmus maximus. We also evaluated the ensuing toxic performance of Phe in S. maximus after been transferred from A. salina in the presence and absence of nTiO2. The presence of nTiO2 significantly (p < 0.05) increased Phe accumulation in A. salina with higher bioconcentration factor (BCF) up to 90.9 than that of 38.6 in Phe exposure along. After trophic transfer, nTiO2 (1 mg/L) also promoted the bioaccumulation of Phe (1 μg/L) in predator S. maximus from 4.17 mg/kg to 7.85 mg/kg (dry weight). However, nTiO2 did not enhance the trophic transfer of Phe from A. salina to S. maximus since the biological magnification factor (BMF) decreased from 0.13 to 0.08. Nevertheless, the nTiO2-enhanced bioaccumulation of Phe did enhance Phe toxicity performance in predator S. maximus after trophic transfer, showing significant (p < 0.05) growth inhibition and changes of nutrient status in the predator, compared to those of the control. Further physio-biochemical investigations suggested that oxidative stress and inhibition of digestive functions might explain the growth inhibition in treatment with nTiO2 + Phe. This study demonstrates the first evidence that NP-enhanced bioaccumulation and toxic performance of co-existing pollutants across trophic transfer, which poses potential risks to marine ecosystems, and ultimately human health by seafood consumption.

The Effect of Multi-Vitamin/Multi-Mineral Supplementation on Nutritional Status in Older Adults Receiving Drug Therapies: A Double-Blind, Placebo-Controlled Trial

Polypharmacy regimens may increase the susceptibility of older adults to micronutrient inadequacy and deficiency via impairment of nutritional status. We hypothesized that a multi-vitamin-mineral supplement (MVMS) could improve nutritional status in older adults prescribed diuretics, metformin, and/or proton pump inhibitors (PPIs). We conducted a randomized, double-blind, placebo controlled, parallel clinical trial in which eligible subjects were instructed to consume either a MVMS or placebo for 16 wk. Fasting blood was collected at baseline, 8, and 16 wk and the status of selected vitamins and minerals determined. Thirty-five and 19 men and women aged 45–75 yrs in the in MVMS and placebo arms, respectively, completed the trial. The mean total number of medications among the three drug classes taken by participants did not differ between two groups. The status of vitamins B1, B12, C and folate and calcium, copper, magnesium and zinc at baseline were within normal ranges. The MVMS group had a greater change in nutrient status after 16 wk compared to the placebo group for serum folate (7.5 vs. –1.6 ng/mL, p < 0.0001), vitamin B12 (159.2 vs. –33.9 pg/mL, p = 0.007), and plasma vitamin C (0.2 vs. 0.0 mg/dL, p = 0.004). Other measured vitamins and minerals were not significantly changed during the intervention. In conclusion, the status of vitamins B12, C and folate improved with MVMS but remained within normal ranges in older adults taking diuretics, metformin, and/or PPIs.

Chemocline collapse in Lake Kivu as an analogue for nitrogen cycling during Oceanic Anoxic Events

One of the outstanding issues in the study of nutrient dynamics during Oceanic Anoxic Events (OAEs) is the preservation of 15N-depleted nitrogen isotope signals, which are not observed in analogous modern environments. The favored mechanism for δ15N values below 0‰ is utilization of excess ammonium derived from underlying anoxic waters by primary producers. However, there are few modern examples available for testing this hypothesis, due to the overall well-oxygenated state of modern oceans. Here, we present sedimentary δ13Corg and δ15Nbulk data, as well as pigment biomarker ratios, from the sediments of Lake Kivu, a meromictic lake in East Africa. This system serves as a potential analogue for the development of strongly depleted δ15Nbulk in OAE black shales. We focus on intervals of organic carbon enrichment (sapropels) that are interpreted to have been the result of lake water column mixing events. Sediment δ13Corg and δ15Nbulk decrease by up to 6 and 4‰ respectively near the base of sapropel layers. These negative excursions provide evidence for the mixing of 13C-depleted dissolved inorganic carbon and ammonium in excess of photosynthetic need, derived from the deeper anoxic basin of the lake. Support of this model is also provided by photosynthetic pigment biomarkers which show significant fluctuations in phototrophic ecology consistent with water column mixing and changes in nutrient status. Further evidence for the shallowing of the chemocline during sapropel deposition is found in the presence of bacteriochlorophyll derivatives produced by phototrophic sulfide oxidizers.