DOC and DON from grass-clover - results from a field experiment

The C and N dynamics in perennial grass-clover mixtures are not fully understood although such mixtures dominate temperate grassland. The co-existence of clover and grass involves both competition for and transfer of nutrients between the species. The nutrients that are competed for and transferred may originate from leaky root systems, from a rapid turnover of the fine root systems, or from degradation of more stabile organic material. The aim of the present study was to investigate the origin of dissolved organic C and N in perennial grass-clover mixtures. In an existing grass-clover ley, field mezotrons (cylinders with a diameter 30 cm) were installed in the spring of 2003 to depths of 20, 40 and 60 cm. Suction cups was installed beneath the mezotrons in order to sample the soil solution during the growth season. In late June 2004 cross-labelling of clover and grass populations in the mezotrons was done by leaf labelling (5 days) of either grass or clover using 15N- and 14C-labelled urea. During the following 3 months the percolating soil solution was sampled either after heavy rain or after irrigation of the mezotrons and the content 15N- and 14C-labelled compounds were determined. Leaf material was harvested at tree times during the growth season and at the end of the growth season the mezotrons was excavated and the distribution of 15N and 14C in the plants and soil determined. 14C was detected in the percolating soil solution imediately after leaf-labelling was initiated, with the highest amounts occuring from labelled grass. The peak of 14C reached the depths of 20 and 40 cm between 3-10 and 5-15 days respectively after labelling was initiated while no 14C was detected beneath the 60 cm mezotrons. The majority of 14C in soil solution was identified to be 14CO2 originating either from root respiration or from biomass respiration of 14C-labelled root parts or root exudates. The transfer of 14C was higher from grass to clover than vice versa. This transfer of 14C properly occurs as 14CO2 exchange between the leaves or in the root zone. Transfer of 15N was highest from clover to grass, while the transfer from grass to clover was negligible. These observations confirm previous investigations of 15N transfer between grass and clover. No clear connection was found between the transfer of 14C and 15N. After excavation of the mezotrons 14C was found in higher amounts and at larger depths in the soil for grass compared to clover. The results from this experiment point to that in a grass-clover ley carbon would primarily originate from grass and nitrogen would come from clover. The depths at which 14CO2 is found in the soil solution seem to be somewhat related to the depth of 14C-labelled root material meaning that the rooting profile of a crop influence the deposition of carbon and nitrogen in the soil matrix. These findings add significant new dimensions to our current understanding of processes governing the build up of soil fertility under grass-clover leys

Dairy Carbon Credits

An overview of trends and opportunities in the carbon credits market

Mars manned fusion spaceship

Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium-3. Helium-3 can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system

Course Re-Design: What’s New on Campus

In a session designed to impact how you think about designing your classes, Dr. Jim Gigantino, Interim Vice Provost for Academic Affairs, will lead a discussion of the new modes of delivery that will be available on campus and some information about the mixed mode pilot that will be undertaken in the fall of 2023. Dr. David Jensen, Associate Professor of Mechanical Engineering, will discuss a course he designed to be taught in a mixed mode form and share how he has been using the materials the last couple of semesters. He will provide examples from his class along with two instructional designers from the Global Campus, Adam Brown and Ken Muessig, who assisted him as part of a TFSC grant. Kathryn Zawisza, Director of Academic Tech and Innovation, will discuss how Blackboard Ultra can help with re-designing a course due to the ease in using it across multiple devices. Information in the session can be useful to incorporate in your day to day classes, potential winter weather days, or even a new way of teaching your classes each semester

Forage herbs improve mineral composition of grassland herbage

Provision of an adequate mineral supply in the diets of ruminants fed mainly on grassland herbage can present a challenge if mineral concentrations are suboptimal for animal nutrition. Forage herbs may be included in grassland seed mixtures to improve herbage mineral content, although there is limited information about mineral concentrations in forage herbs. To determine whether herbs have greater macro- and micromineral concentrations than forage legumes and grasses, we conducted a 2-year experiment on a loamy-sand site in Denmark sown with a multi-species mixture comprised of three functional groups (grasses, legumes and herbs). Herb species included chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), caraway (Carum carvi L.) and salad burnet (Sanguisorba minor L.). We also investigated the effect of slurry application on the macro- and micromineral concentration of grasses, legumes and herbs. In general, herbs had greater concentrations of the macrominerals P, Mg, K and S and the microminerals Zn and B than grasses and legumes. Slurry application indirectly decreased Ca, S, Cu and B concentrations of total herbage because of an increase in the proportion of mineral-poor grasses. Our study indicates that including herbs in forage mixtures is an effective way of increasing mineral concentrations in herbage

Bombesin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

Mammalian bombesin (Bn) receptors comprise 3 subtypes: BB1, BB2, BB3 (nomenclature recommended by the NC-IUPHAR Subcommittee on bombesin receptors, [109]). BB1 and BB2 are activated by the endogenous ligands gastrin-releasing peptide (GRP), neuromedin B (NMB) and GRP-(18-27). bombesin is a tetradecapeptide, originally derived from amphibians. The three Bn receptor subtypes couple primarily to the Gq/11 and G12/13 family of G proteins [109]. Each of these receptors is widely distributed in the CNS and peripheral tissues [73, 109, 236, 265, 226, 348]. Activation of BB1 and BB2 receptors causes a wide range of physiological/pathophysiogical actions, including the stimulation of normal and neoplastic tissue growth, smooth-muscle contraction, feeding behavior, secretion and many central nervous system effects including regulation of circadian rhythm and mediation of pruritus [112, 113, 109, 115, 116, 155, 189, 236]. A physiological role for the BB3 receptor has yet to be fully defined although recently studies suggest an important role in glucose and insulin regulation, metabolic homeostasis, feeding, regulation of body temperature, obesity, diabetes mellitus and growth of normal/neoplastic tissues [73, 157, 203, 332]

Bombesin receptors in GtoPdb v.2023.1

Mammalian bombesin (Bn) receptors comprise 3 subtypes: BB1, BB2, BB3 (nomenclature recommended by the NC-IUPHAR Subcommittee on bombesin receptors, [117, 4]). BB1 and BB2 are activated by the endogenous ligands neuromedin B (NMB), gastrin-releasing peptide (GRP), and GRP-(18-27). bombesin is a tetra-decapeptide, originally derived from amphibians and structurally closely related to GRP. The three Bn receptor subtypes couple primarily to the Gq/11 and G12/13 family of G proteins [117]. Each of these receptors is widely distributed in the CNS and peripheral tissues [80, 117, 261, 290, 248, 375, 114, 164, 165]. Activation of BB1 and BB2 receptors causes a wide range of physiological/pathophysiogical actions, including the stimulation of normal and neoplastic tissue growth, smooth-muscle contraction, respiration, gastrointestinal motility, feeding behavior, secretion and many central nervous system effects including regulation of circadian rhythm, body temperature control, sighing, behavioral disorders and mediation of pruritus [153, 211, 255, 117, 205, 261, 318, 70, 35, 345, 212, 36]. BB3 is an orphan receptor, although some propose it is constitutively active [330]. BB3 receptor knockout studies show it has important roles in glucose and insulin regulation, metabolic homeostasis, feeding, regulation of body temperature, obesity, diabetes mellitus and growth of normal/neoplastic tissues [152, 80, 168, 224, 359, 209]. Bn receptors are one of the most frequently overexpressed receptors in cancers and are receiving increased attention for their roles in tumor growth, as well as for tumour imaging and for receptor-targeted cytotoxicity [211, 288, 9, 167, 171, 172, 135, 202]. Bn receptors are also receiving attention because they are one of the primary neurotransmitters for pruritus [36, 127, 35, 318]