Sorption, degradation and transport of veterinary antibiotics in New Zealand pastoral soils

Veterinary antibiotics are used worldwide for prevention and treatment of various diseases of livestock animals. After administration, the majority of antibiotics are excreted in urine and faeces as unchanged parent compound, and/or as their metabolites. With increases in the intensive use of antibiotics in New Zealand agriculture and direct land application of waste as manure, there is concern that excreted compounds could migrate to the receiving environment with potential impact on surface and groundwater. Antibiotic residues in soil could give rise to a variety of ecotoxicological problems and could also confer antibiotic resistance. As a first step towards assessing the risk of these compounds, it is important to investigate their fate and behaviour in the soil environment. The focus of this work was to determine the fate and transport behaviour of selected group of veterinary antibiotics in several New Zealand pastoral soils. A macrolide (TT) and three sulfonamide antibiotics (SMO, SCP and SM) were chosen for this study as they are commonly used overseas as well as in New Zealand. A simple, yet robust analytical method was developed to detect and quantify TT and the three sulfonamides using high performance liquid chromatography and ultraviolet detection. The limits of detection at signal: noise ratio of 3 were 20.0 µg L⁻¹ and 50 µg L⁻¹ for all SA’s and TT respectively. The average recoveries for all SA’s and TT in aqueous matrices ranged from 95 to 105% across the six concentrations investigated. Recoveries from the residual soils were slightly lower for SA’s and TT (~ 50 to 60%). The results of the kinetics studies showed that sorption was rapid in the first few hours of the contact time (0 to 2 h for SA’s and 0 to 4 h for TT) and thereafter an apparent equilibrium concentration was achieved slowly. Batch sorption results performed in six different pastoral soils showed that Freundlich isotherms were nonlinear (N ≠ 1) for most of the compounds. The degree of isotherm linearity (N) for SCP and SM varied between 0.87–1.11 in the six soils. SMO showed a highly non-linear pattern (N = 0.75) in just one soil (Manawatu). Isotherms of both TT and SMO were non-linear, with the degree of non-linearity for TT (N = 0.41–0.73) being greater than for SMO (0.88–1.21) in all soils. Concentration-dependent effective distribution coefficient (Kdeff ) values for the SMO, SCP and SM antibiotics in the soils ranged from 0.37 to 4.6 L kg⁻¹ and for TT Kdeff ranged from 1.2 to 500 L kg⁻¹. The sorption affinity for all soils followed an order: TT > SCP > SM > SMO. Statistical analysis of sorption data revealed a correlation between the sorption coefficients and soil properties such as % organic carbon, cation exchange capacity and clay content. Sorption of TT onto soils is mostly driven by the cation exchange capacity of the soil whereas for sulfonamides it is primarily due to hydrophobic interactions due to hydrophobic interactions. On further investigation it was found that sorption of the SMO antibiotic to soils was highly dependent on pH, ionic strength, and organic matter of the soil. Sorption of SMO decreased with the increases in pH, and increased with increasing ionic strength and organic carbon content. A hydrophobic pH-partitioning model linking sorbate speciation with species-specific sorption coefficients describing the pH dependence of the apparent sorption coefficients was successfully used to derive the fraction of each species of SMO that are likely to be present in the environment. The results from the biochar amended sorption studies showed that certain biochars can be used as a potential tool to remove residues of antibiotics. Soil amended with pine saw dust biochar was found to be the most effective in adsorbing antibiotics. Pine sawdust biochar absorbed 30 times more antibiotics than soil alone. This was attributed to its high surface area, which was four times higher than that of other biochars, or could be due to its high carbon content (91%). The results have shown that biochar applied at the rate of 0.5 to 1% by soil weight could prove to be an effective way to slow down the release of these contaminants to a manageable level thereby reducing the risk of ecotoxicity and antibiotic resistance. SMO degraded slowly in agricultural soils. The degradation times (DT₅₀) for SMO in Hamilton clay, Te Kowhai and Horotiu soils under non-sterilized conditions were 9.24, 4.3 and 13.33 days respectively. Soil dehydrogenase activities were directly correlated with degradation kinetics of SMO antibiotic. Results from degradation studies have shown that SMO is not likely to persist more than 90 days in all three soils suggesting that natural biodegradation may be sufficient for the removal of these contaminants from the soil. Both the degree of biological activity and temperature of the soil influenced overall degradation. SMO degradation in sterile soils indicated abiotic degradation and abiotic factors such as strong sorption of the antibiotic onto soil components also played a role in the degradation of SMO in soil. Four kinetic models, a single first-order model (SFO) and three biphasic kinetic models, were applied to fit the observed SMO degradation kinetics data. The results showed that the First-order double-exponential decay (FODED) and first-order two-compartment (FOTC) model was superior to the bi-exponential model (BEXP) and all three biphasic models were superior when compared to the SFO model for describing SMO degradation data. Use of the FOTC model enabled the estimation of the degradation endpoints. The results from two soil lysimeters indicate that the three sulfonamides were highly mobile and that at field collected soil pH mobility was similar to the mobility of the conservative bromide. The breakthrough curves of the three sulfonamides varied depending on soil type with Hamilton soil showing more retardation than Matawhero soil. For the three sulfonamides studied the order of breakthrough was generally observed to be: SM > SMO > SCP for both Matawhero and Hamilton soils. Residual antibiotic concentrations for SMO and SCP were detected up to depths of 18 cm. The CXTFIT model study described the peak arrival time as well as the maximum concentration of the antibiotic breakthrough curves but showed some underestimation at advanced stages of sulfonamide leaching, especially in the Hamilton soil. Results showed that the sulfonamides have weak sorption affinity and relatively high mobility in soils

Herbicidal Control of Grasses

Necessity of the herbicidal application for controlling undesirable grasses, by the Defence Services, Military farms and Inter Service Organisations is highlighted. Control of grasses by herbicidal chemicals, registered under the Insecticides Act 1968 in this country, is reviewed apart from a mention of non-chemical methods

Sorption of sulfamethoxazole, sulfachloropyridazine and sulfamethazine onto six New Zealand dairy farm soils

We have investigated the sorption potential of three sulfonamides (SAs) in six New Zealand dairy farming soils using a modified batch equilibrium method employing 0.005 M CaCl₂ as background solution. Both liquid and solid phases were extracted to analyse for the antibiotic concentrations in order to avoid underestimation that may arise a result of photolysis or biotic degradation. The experimental data were later used to construct Freundlich isotherms to determine the effective distribution coefficients. Low log Koc value for all SAs suggests considerable leaching potential for SAs under conditions that are conducive for leaching. The sorption affinity for all soils followed the trend SCP>SMZ>SMO

Modular Scan Test for SoC Design

In this paper we try to reconfigure the existing scan system to a Modular Scan (MS) in order to adapt itself for future complexities of the chip design. One specific application of MS is the Multiprocessor System-on-Chip (MPSoC) design, where each core can have its own scan chain and also have concurrent testing procedure. MS is a process of arranging the scan chains flexibly for multiple usages during scan test. MS can be used in large chip designs to reduce the length of scan chains, and to reduce the testing time. MS based tests allow the test engineer to easily reconstruct the scan chain in an MPSoC design, if any of the existing cores needs to be replaced with a new core in order to meet the new set of specifications. To achieve such a type of testing, generic scan chain architecture needs to be developed in order to ensure an easy plug-n-play scan chain in the system architecture

Modular Scan Test for SoC Design

In this paper we try to reconfigure the existing scan system to a Modular Scan (MS) in order to adapt itself for future complexities of the chip design. One specific application of MS is the Multiprocessor System-on-Chip (MPSoC) design, where each core can have its own scan chain and also have concurrent testing procedure. MS is a process of arranging the scan chains flexibly for multiple usages during scan test. MS can be used in large chip designs to reduce the length of scan chains, and to reduce the testing time. MS based tests allow the test engineer to easily reconstruct the scan chain in an MPSoC design, if any of the existing cores needs to be replaced with a new core in order to meet the new set of specifications. To achieve such a type of testing, generic scan chain architecture needs to be developed in order to ensure an easy plug-n-play scan chain in the system architecture

A Comprehensive Approach to Supporting Homeless Communities through Free Clinical Screenings

Hearts for the Homeless Orlando is a part of an international organization that is “focused on eliminating health disparities through practicing preventative healthcare and providing free healthcare services.” At each event, free heart health and eye health screenings and education are given to the homeless population in Downtown Orlando. Once arriving at the screening location (Christian Service Center), a table is set up with 2 blood pressure monitors, the KardiaMobile EKG Monitor, hand sanitizing wipes, germicidal wipes, gloves, and pamphlet handouts. These supplies help volunteers understand the health conditions of the individuals who visit to the site, and allow volunteers to recommend them to nearby free health clinics to further check up on them. H4H has worked with the Mothers and Children’s Health Association to host donation drives, as well as with Service and Love Together to provide mobile showering for the homeless population.https://stars.library.ucf.edu/hip-2023fall/1008/thumbnail.jp

Developing the Computational Building Blocks for General Intelligent in SOAR

Cognitive architecture's purpose is to generate artificial agents with capacities similar to the human mind. Soar Cognitive Architecture is to produce the fixed computational building blocks needed for generally intelligent agents— agents that can outright a variety of tasks and encode, use, and learn all types of knowledge to realize the broad cognitive abilities present in humans. This paper introduced an arithmetic agent that does multicolumn, two-digit addition in SOAR. Here, we show the entire calculating procedure, including all of its operators. We are using episodic memory assistance to enhance the set of cognitive abilities that let the agent learn and reason

STUDIES ON THE PHYTOCHEMICAL SCREENING AND FREE RADICAL SCAVENGING POTENTIALS OF SOLANUM NIGRUM LEAVES EXTRACT

ABSTRACTSolanum nigrum is a paramount in medicinal perspective and belongs to family Solanacea. From different parts of the plant significant pharmacological and biological activities have been reported previously.  In the present study, the ethanolic extract of leaves was investigated for phytochemical analysis, vitamin and mineral content. Phytochemical analysis of the leaves revealed the presence of phenols, alkaloids, flavonoids, glycosides, saponins, tannins, phytosterols and triterpenoides. The leaves extract was found to contain appreciable amounts of flavonoids and phenols. The extract showed the presence of vitamins such as ascorbic acid, folic acid, and niacinamide. It has been found that the leaves of Solanum nigrum is rich in minerals like copper, magnesium, manganese, vanadium, chromium, calcium, zinc, sodium, and potassium. The antioxidant (free radical scavenging) activity of the extract was determined against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ABTS, Nitric oxide(NO) and Superoxide Scavenging assays. Solanum nigrum leaves extract was found to be antioxidant in nature which is evident from DPPH, ABTS, NO, Superoxide radical scavenging assays. These findings suggest that Solanum nigrum possess biologically important phytoconstituents, significant amounts of vitamins and minerals. IN addition, S. nigrum leaves extract exert free radical scavenging potential in vitro.Key words: Medicinal plants; Solanum nigrum leaves; phytoconstiuents;Antioxidant. Â

ArrayD: A general purpose software for Microarray design

BACKGROUND: Microarray is a high-throughput technology to study expression of thousands of genes in parallel. A critical aspect of microarray production is the design aimed at space optimization while maximizing the number of gene probes and their replicates to be spotted. RESULTS: We have developed a software called 'ArrayD' that offers various alternative design solutions for an array given a set of user requirements. The user feeds the following inputs: type of source plates to be used, number of gene probes to be printed, number of replicates and number of pins to be used for printing. The solutions are stored in a text file. The choice of a design solution to be used will be governed by the spotting chemistry to be used and the accuracy of the robot. CONCLUSIONS: ArrayD is a software for standard cartesian robots. The software aids users in preparing a judicious and elegant design. ArrayD is universally applicable and is available at