Search

Manure produced in Midwestern U.S. pig finishing facilities is usually stored in concrete deep-pits beneath the building before land application. Manure foaming in deep-pit barns has recently become a problem, causing a safety hazard. Since no obvious cause for this foaming was observed, compositional analysis was conducted to reveal differences between foaming and non-foaming manure samples to determine any specific components that can be correlated to foaming. Result shows that foaming manure samples have higher concentrations of solids, lipids, trace metals, and proteins than non-foaming samples. [ABSTRACT FROM AUTHOR]

Foaming in deep manure pits beneath swine buildings has become a serious safety concern during the past few years in the Midwestern U.S. In addition to the loss of manure storage capacity, this foaming creates a serious safety risk of flash fires and explosions. In order to understand the mechanism of manure foaming, manure samples taken from foaming and non-foaming pits were studied to reveal potential causes. Among various compositional components found in the foaming and non-foaming manure samples, long-chain fatty acids (LCFA) were found to be a major contributing factor. Adding or removing LCFA in swine manure samples led to a significant change in their foaming capability. A significantly higher concentration of LCFA was also detected in the foam layers of foaming manure samples. LCFA surfactants are stimulating foaming, and the sources of these surfactants need to be determined in order to develop long-term mitigation plans for manure foaming. [ABSTRACT FROM AUTHOR]

Demonstrates the agreement between clades inferred from phylogenetic analysis of internal transcribed spacer region sequences and groups of species of Salsola based on morphological and physiological data. Characterization of two anatomical types of Salsoleae; Discussion of the five clades within the NADP-ME lineage; Evolutionary patterns in Salsoleae.

The natural geographical occurrence, carbon assimilation, and structural and biochemical diversity of species with C4 photosynthesis in the vegetation of Mongolia was studied. The Mongolian flora was screened for C4 plants by using 13C/12C isotope fractionation, determining the early products of 14CO2 fixation, microscopy of leaf mesophyll cell anatomy, and from reported literature data. Eighty C4 species were found among eight families: Amaranthaceae, Chenopodiaceae, Euphorbiaceae, Molluginaceae, Poaceae, Polygonaceae, Portulacaceae and Zygophyllaceae. Most of the C4 species were in three families: Chenopodiceae (41 species), Poaceae (25 species) and Polygonaceae, genus Calligonum (6 species). Some new C4 species in Chenopodiaceae, Poaceae and Polygonaceae were detected. C4 Chenopodiaceae species make up 45% of the total chenopods and are very important ecologically in saline areas and in cold arid deserts. C4 grasses make up about 10% of the total Poaceae species and these species naturally concentrate in steppe zones. Naturalized grasses with Kranz anatomy,of genera such as Setaria, Echinochloa, Eragrostis, Panicum and Chloris, were found in almost all the botanical-geographical regions of Mongolia, where they commonly occur in annually disturbed areas and desert oases. We analyzed the relationships between the occurrence of C4 plants in 16 natural botanical-geographical regions of Mongolia and their major climatic influences. The proportion of C4 species increases with decreasing geographical latitude and along the north-to-south temperature gradient; however grasses and chenopods differ in their responses to climate. The abundance of Chenopodiaceae species was closely correlated with aridity, but the distribution of the C4 grasses was more dependent on temperature. Also, we found a unique distribution of different C4 Chenopodiaceae structural and biochemical subtypes along the aridity gradient. NADP-malic enzyme (NADP-ME) tree-like species with a salsoloid type of Kranz anatomy, such as Haloxylon ammodendron and Iljinia regelii, plus shrubby Salsola and Anabasis species, were the plants most resistant to ecological stress and conditions in highly arid Gobian deserts with less than 100 mm of annual precipitation. Most of the annual C4 chenopod species were halophytes, succulent, and occurred in saline and arid environments in steppe and desert regions. The relative abundance of C3 succulent chenopod species also increased along the aridity gradient. Native C4 grasses were mainly annual and perennial species from the Cynodonteae tribe with NAD-ME and PEP-carboxykinase (PEP-CK) photosynthetic types. They occurred across much of Mongolia, but were most common in steppe zones where they are often dominant in grazing ecosystems. [ABSTRACT FROM AUTHOR]

Haloxylon aphyllum and H. persicum of Chenopodiaceae are dominant plants in the continental deserts of the Asian Irano-Turanian region. The photosynthetic organs, assimilating shoots and leaf-like cotyledons of these two species were studied to characterize their photosynthetic types. 13C/12C isotope ratios, the cellular anatomy of as similating organs, primary photosynthetic products, and activities of carbon metabolism enzymes, RUBP carboxylase, PEP carboxylase, malic enzymes, and aspartate aminotransferase, indicate different pathways of CO2 fixation in the photosynthetic organs. Assimilating shoots had attributes of the C4 photosynthesis entirely, while cotyledons lack Kranz-anatomy and incorporated CO2 via C3 photosynthesis. Cotyledons and seeds had lower δ13C values compared to shoots, consistent with the contribution of C3-like CO2 assimilation. Two pathways of carbon donation to the C3 cycle via decarboxylation of C4 acids in bundle sheath cells are suggested to occur in shoots of Haloxylon. The primary photosynthetic product malate can be utilized through NADP+-malic enzyme which occurs in high activity. NADδ-malic enzyme may contribute to C4 photosynthesis (some aspartate is formed as an initial product, the bundle sheath chloroplasts have some grana, and NAD+-malic enzyme is found in bundle sheath cells of shoots, all criteria for NAD+-malic enzyme type photosynthesis). We propose that organ diversity of CO2 fixation pathway in Haloxylon species is an important factor for their growth, survival and reproduction in continental climate deserts. [ABSTRACT FROM AUTHOR]

Sucrose is the starting point of glycolysis and end point of gluconeogenesis in higher plants. During both glycolysis and gluconeogenesis alternative enzymes are present at various steps to carry out parallel pathways; alternatives are available for utilizing nucleotide triphosphates and pyrophosphate; fructose 2,6‐bisphosphate serves as a strong internal regulator; and plants use these cytoplasmic alternatives as they develop and as their environments change. [ABSTRACT FROM AUTHOR]

Plant cells have two cytoplasmic pathways of glycolysis and gluconeogenesis for the reversible interconversion of fructose 6‐phosphate (F‐6‐P) and fructose 1,6‐bisphosphate (F‐1,6‐P2). One pathway is described as a maintenance pathway that is catalyzed by a nucleotide triphosphate‐dependent phosphofructokinase (EC 2.7.1.11; ATP‐PFK) glycolytically and a F‐1,6 bisphosphatase (EC 3.1.3.11) gluconeogenically. These are non‐equilibrium reactions that are energy consuming. The second pathway, described as an adaptive pathway, is catalyzed by a readily reversible pyrophosphate‐dependent phosphofructokinase (EC 2.7.1.90; PP‐PFK) in an equilibrium reaction that conserves energy through the utilization and the synthesis of pyrophosphate. A constitutive regulator cycle is also present for the synthesis and hydrolysis of fructose 2,6‐bisphosphate (F‐2,6‐P2) via a 2‐kinase and a 2‐phosphatase, respectively. The pathway catalyzed by the ATP‐PFK and F‐1,6‐bisphosphatase, the maintenance pathway, is fairly constant in maximum activity in various plant tissues and shows less regulation by F‐2,6‐P2. Plants use F‐2,6‐P2 initially to regulate the adaptive pathway at the reversible PPi‐PFK step. The adaptive pathway, catalyzed by PPi‐PFK, varies in maximum activity with a variety of phenomena such as plant development or changing biological and physical environments. Plants can change F‐2,6‐P2 levels rapidly, in less than 1 min when subjected to rapid environmental change, or change levels slowly over periods of hours and days as tissues develop. Both types of change enable plants to cope with the environmental and developmental changes that occur during their lifetimes. The two pathways of sugar metabolism can be efficiently linked by the cycling of uridylates and pyrophosphate required for sucrose breakdown via a proposed sucrose synthase pathway. The breakdown of sucrose via the sucrose synthase pathway requires half the net energy of breakdown via the invertase pathway. Pyrophosphate occurs in plant tissues as a substrate pool for biosynthetic reactions such as the PPi‐PFK or uridine diphosphate glucose pyrophosphorylase (EC 2.7.7.9; UDPG pyrophosphorylase) that function in the breakdown of imported sucrose. Also, pyrophosphate links the two glycolytic/gluco‐neogenic pathways; and in a reciprocal manner pyrophosphate is produced as an energy source during gluconeogenic carbon flow from F‐1,6‐P2 toward sucrose synthesis. [ABSTRACT FROM AUTHOR]

We studied root and stem sucrose metabolism in trees excavated from a 9-year-old artificially regenerated loblolly pine (Pinus taeda L.) plantation. Sucrose synthase (SS) activities in stem and taproot vascular cambial tissues followed similar seasonal patterns until they peaked during September. After September, stem SS activity disappeared quickly, whereas taproots exhibited SS activity even in January. Pyrophosphate-dependent phosphofructokinase (PPi-PFK) activity tracked SS activity. The activities of ATP-dependent PFK and several other glycolytic enzymes (e.g., phosphoglucomutase and phosphoglucoisomerase) remained relatively constant in cambial tissues of stem, taproot, and all first-order lateral roots (FOLRs) throughout the year. However, during the growing season, individual FOLRs exhibited variable sucrose metabolic activities that were independent of root diameter or position on the taproot. The FOLRs with low or no SS activity also had low PPi-PFK activity. We propose that when intense competition for sucrose occurs among different organs of a tree, the variable activities of the sucrose metabolic enzymes in FOLRs ensure that enough sucrose is allocated to the stem and taproot for growth. For a tree's long-term survival and growth, second or higher-order roots can be sacrificed, whereas FOLRs, stem and taproot are essential. [ABSTRACT FROM PUBLISHER]

About 95% of swamp tupelo (Nyssa sylvatica var. biflora (Walt.) Sarg.) and sweetgum (Liquidambar styraciflua L.) seedlings survived continuous root flooding for more than two years, whereas none of the swamp chestnut oak (Quercus michauxii Nutt.) and cherrybark oak (Q. falcata var. pagodifolia Ell.) seedlings survived one year of flooding. Death of oak seedlings occurred in phases associated with periods of major vegetative growth, e.g., after bud burst in spring, after summer stem elongation, and during the winter deciduous stage, suggesting that stored reserves and sources were inadequate to maintain the seedlings when vegetative sinks were forming. Additional evidence that flooding induced a source deficiency in oak was that leaves of flooded oak were 65 to 75% smaller than leaves of nonflooded oak. Flooded swamp tupelo seedlings had a normal leaf size and patchy stomatal opening compared with nonflooded seedlings. [ABSTRACT FROM PUBLISHER]

Determines the viability and infectivity of porcine reproductive and respiratory syndrome virus (PRRSV) in swine effluent lagoon. Details on the administration of swine waste purification facility; Evaluation of the infectious PRRSV for the animals; Findings on the risk of swine herds infected with the virus following contact with contaminated lagoon water.