Trace Metal Concentrations across Trophic Levels in Cotton Fields of Xinjiang Province, China

Trace metals become concentrated in urban and peri-urban soils with the use of agricultural practices and industrial emissions. Fertilizers, liming, sewage sludge, and irrigation water contain metals which accumulate in agricultural fields and pose a risk to humans and wildlife. Coal plants and brickyards release metals into the atmosphere which are deposited on soil and plant surfaces. This research quantifies the concentrations of nine trace metals in three different soil types. A total of 116 rodents were sampled in cotton fields and a desert. Cotton plants and triplicate soil samples were collected with each rodent capture. Soil samples were analyzed for organic carbon content, pH, soil texture, and trace metal concentrations. Soil, cotton plants, and rodents were digested and trace metal concentrations determined. Significant differences of nine trace metals, As, Ca, Cd, Cr, Cu, Ni, Pb, Se, and Zn, were found across three different soil types. Rodent tissue metal concentrations were found to be significantly different across soil types; As and Se were highest in loam soils. The lowest concentration of Cr in rodent tissue was found in fields with loam soil. Nine trace metal concentrations were not significantly different across five different species of rodents. Soil texture can influence the availability of trace metals; High clay soils can bind to metals decreasing their bioavailability

SPATIOTEMPORAL PATTERNS OF DISSOLVED ORGANIC NUTRIENT LABILITY ACROSS THE SUBTROPICAL NORTH PACIFIC

Net biologically produced organic matter integrated over an annual cycle in the euphotic zone of the global ocean is equal to annual net community production (ANCP). ANCP is limited by the rate of delivery of essential nutrients (nitrogen (N), phosphorus (P), and iron (Fe)) to the sunlit surface ocean and the efficiency with which these nutrients are either metabolized or returned to the ocean’s interior. In subtropical oceans, which are regions of large-scale downwelling and consequently characteristic of nutrient-depleted surface waters, ANCP remains comparable to more nutrient replete ecosystems (~2 – 5 mol C m-2 yr-1). To understand what may fuel this productivity, analyses of dissolved organic matter (DOM) within the upper 500 meters of the subtropical North Pacific gyre were performed. Observed meridional gradients suggest the consumption of dissolved organic phosphorus (DOP) and bioavailable dissolved organic nitrogen (bDON) may contribute bioavailable P and N on the order of 8.8 ± 2.2 mmol P m-2 y-1 and 14.3 ± 3.7 mmol N m-2 y-1 along the northward transit of waters from the southern edge towards the gyre core. Additionally, bioassay incubation experiments were performed within two vertically distinct layers of the euphotic zone to quantify the magnitude and rate of heterotrophic DOP remineralization in surface waters (5 m) and the deep chlorophyll maximum (DCM) (125 m) at two stations in the subtropical North Pacific; Station ALOHA (22.75°N) and 31°N along a transect on 158°W, north of Oahu, HI. Evidence for a measurable pool of labile DOP present in surface waters on the order of 25 – 60 nM was found to be consumed in ~5 days near the southern edge of the gyre at Station ALOHA. This consumption was ~1/3 of the latitudinal gradient in surface waters to 31°N, the core of the gyre. Additionally, a new method was deployed to estimate the fraction of the bulk dissolved organic nitrogen (DON) pool composed of bioavailable DON (bDON). A similar meridional gradient in surface ocean bDON was observed on the order of 230 nM N across the gyre, with a DON pool that was comprised of ~13.3 ± 3.5% bDON. The meridional gradients observed in the size of the surface ocean labile DOP and DON pools found in this study largely affirms the importance of upper-ocean lateral organic nutrient transport on supplying North Pacific subtropical gyre surface waters with bioavailable phosphorus and nitrogen and provides important observational data to validate existing models of marine organic nutrient cycling

ANALISIS PERTUMBUHAN EKONOMI JAWA TENGAH DAN FAKTOR YANG MEMPENGARUHI BERDASARKAN PDRB

Economic conditions in Central Java Province have improved from time to time. So that a study was conducted to determine and analyze the factors that can affect the economic growth of Central Java Province for the 2020 period with reference to the 2015-2020 PDRB. The data is collected through the Central Java Statistics Agency and will be analyzed through the stages of data reduction, data display and conclusion drawing. The results of the analysis show that the increase in PDRB in 2015 to 2019 shows very good economic growth in Central Java but due to the pandemic period, PDRB in 2020 has decreased due to limited public consumption activities, government spending, investment and exports and imports. In the future, the Central Java Government can focus on infrastructure development and empowering the poor as well as creating open job opportunities for the unemployed

Not So Heavy Metals: Black Hole Feedback Enriches The Circumgalactic Medium

We examine the effects of SMBH feedback on the CGM using a cosmological hydrodynamic simulation \citep[{\sc Romulus25};][]{Tremmel2017} and a set of four zoom-in `genetically modified' Milky Way-mass galaxies sampling different evolutionary paths. By tracing the distribution of metals in the circumgalactic medium (CGM), we show that \ion{O}{6} is a sensitive indicator of supermassive black hole (SMBH) feedback. First, we calculate the column densities of \ion{O}{6} in simulated Milky Way-mass galaxies and compare them with observations from the COS-Halos Survey. Our simulations show column densities of \ion{O}{6} in the CGM consistent with those of COS-Halos star forming and quenched galaxies. These results contrast with those from previous simulation studies which typically underproduce CGM column densities of \ion{O}{6}. We determine that a galaxy's star formation history and assembly record have little effect on the amount of \ion{O}{6} in its CGM. Instead, column densities of \ion{O}{6} are closely tied to galaxy halo mass and BH growth history. The set of zoom-in, genetically modified Milky Way-mass galaxies indicates that the SMBH drives highly metal-enriched material out into its host galaxy's halo which in turn elevates the column densities of \ion{O}{6} in the CGM.Comment: 14 pages, 12 figures, Submitted to ApJ; Note: Figures have transparency that may not render in browse

Enzymatic Activity Detection via Electrochemistry for Enceladus

Electrochemical detection of biological molecules is a pertinent topic and application in many fields such as medicine, environmental spills, and life detection in space. Proteases, a class of molecules of interest in the search for life, catalyze the hydrolysis of peptides. Trypsin, a specific protease, was chosen to investigate an optimized enzyme detection system using electrochemistry. This study aims at providing the ideal functionalization of an electrode that can reliably detect a signal indicative of an enzymatic reaction from an Enceladus sample

Electrochemical Detection of the Molecules of Life

All forms of life on Earth contain cellular machinery that can transform and regulate chemical energy through metabolic pathways. These processes are oxidation-reduction reactions that are performed by four key classes of molecules: flavins, nicotinamaides, porphyrins, and quinones. By detecting the electrochemical interaction of these redox-active molecules with an electrode, a method of differentiating them by their class could be established and incorporated into future life-detecting missions. This body of work investigates the electrochemistry of ubiquitous molecules found in life and how they may be detected. Molecules can oxidise or reduce the surface of an electrode - giving or receiving electrons - and these interactions are represented by changes in current with respect to an applied voltage. This relationship varies with: electrolyte type and concentration, working electrode material, the redox-active molecule itself, and scan rate. Flavin adenine dinucleotide (FAD), riboflavin, nicotinamide adenine dinucleotide (NADH), and anthraquinone are all molecules found intracellularly in almost all living organisms. An organism-synthesised extracellular redox-active molecule, Plumbagin, was also selected as part of this study. The goal of this work is to detect these molecules in seawater and assess its application in searching for life on Ocean Worlds

When females compete and males care: Phenotypic differences in the spotted sandpiper

Ecology can shape variation in mating systems. Spotted sandpipers (Actitis macularius) are migratory shorebirds with a sequentially polyandrous mating system. Females compete for multiple mates, and males care for offspring, including through incubation and chick care. A study of a Midwestern population found that females have larger body mass and feather spots, but we do not know whether this pattern extends to other populations of this species. We studied a California population of spotted sandpipers surrounding Mono Lake. We used PCR to determine genetic sex from blood samples, and we used R to compare morphological traits between females and males. We find sexual dimorphism in several morphological traits, including tarsus, wing, and bill length, as well as body mass, suggesting the Midwestern and California populations have evolved similarly, and both have sexually dimorphic morphology