Performances of a full-scale novel multiplate anaerobic reactor treating cheese whey effluent

A 450-m(3) multiplate anaerobic reactor (MPAR) has been started-up in April 1992 for treating wastewater (whey permeate and domestic wastewater) at the Nutrinor (Lactel) cheese factory in Chambord (Québec, Canada). The MPAR consists of four superimposed sections. The liquid flows upwards from one section to the next, while the gas is collected below each plate and evacuated through side-outlets. The wastewater is concurrently distributed at the bottom of the first, second, and third sections, as 50%, 33%, and 17% of the total influent stream, respectively. Granular anaerobic sludge at an initial concentration of 30 kg of volatile suspended solids (VSS) per cubic meter of reactor liquid volume was used to inoculate the reactor. Under normal operation of the factory, the chemical oxygen demand (COD) concentration of the influent ranged from 20 to 37 kg COD m(-3). The reactor organic loading rate (OLR) fluctuated between 9 and 14.7 kg COD m(-3) d(-1) for hydraulic retention times (HRT) maintained between 55 and 68 h. At the highest OLR, the MPAR showed an efficiency of 98% and 92% for soluble and total COD removal, respectively, and a methane production rate averaging around 4 m(3) m(-3) d(-1).Biomass-specific activities ranged between 7 and 51, 1.3 and 8.5, 5.3 and 12.2, 60 and 119, and 119 and 211 mmol g(-1) VSS d(-1) for glucose, propionate, acetate, formate, and hydrogen, respectively. Average equivalent-diameter of the granules was around 0.65 mm. The MPAR reactor generally showed a large capacity for solid retention with a biomass content between 32 and 37 kg VSS m(-3). (c) 1995 John Wiley & Sons, Inc.     

Are short normal children at a disadvantage? The Wessex growth study.

OBJECTIVE: To examine whether short stature through childhood represents a disadvantage at around 12 years. DESIGN: Longitudinal non-intervention study of the physical and psychological development of children recruited from the community in 1986-7 after entry into primary school at age 5-6 years; this is the second psychometric assessment made in 1994-5 after entry into secondary school at age 11-13 years. SETTING: Southampton and Winchester health districts. SUBJECTS: 106 short normal children (< 3rd centile for height when recruited) and 119 controls of average stature (10th-90th centile). MAIN OUTCOME MEASURES: Psychometric measures of cognitive development, self concept development, behaviour, and locus of control. RESULTS: The short children did not differ significantly from the control children on measures of self esteem (19.4 v 20.2), self perception (104.2 v 102.4), parents'' perception (46.9 v 47.0), or behaviour (6.8 v 5.3). The short children achieved significantly lower scores on measures of intelligence quotient (IQ) (102.6 v 108.6; P < 0.005), reading attainment (44.3 v 47.9; P < 0.002), and basic number skills (40.2 v 43.5; P < 0.003) and displayed less internalisation of control (16.6 v 14.3; P < 0.001) and less satisfaction with their height (P < 0.0001). More short than control children, however, came from working class homes (P < 0.05). Social class was a better predictor than height of all measures except that of body satisfaction. Attainment scores were predicted by class and IQ together rather than by height. Height accounted for some of the variance in IQ and locus of control scores. CONCLUSIONS: These results provide only limited support for the hypothesis that short children are disadvantaged, at least up until 11-13 years old. Social class seems to have more influence than height on children''s psychological development.     

Gibberellic-acid-promoted transport of assimilates in stems of Phaseolus vulgaris L.

Gibberellic acid (GA₃), applied as a dispersion in aqueous lanolin to the stumps of decapitated stems of P. vulgaris plants, was found to promote the transfer of ¹⁴C-and ³²P-labelled assimilates to the site of hormone application. Measurements of the component transfer processes, operating between source and sink (site of hormone application), showed that GA₃ was not acting to promote assimilate transfer by increasing the photosynthetic rate of, or the assimilate export rate from the source, nor by altering the mobilizing ability of the competing root sink. Here, it also was found that the time between GA₃ application and detection of an enhanced transport flux was independent of the length of the transport pathway. Overall, the evidence obtained indicated that GA₃ was not acting on any transfer process remote from its point of hormone application but was acting locally at this latter point.Abbreviations GA₃ gibberellic acid - IAA indol-3yl-acetic acid     

Protective effects of soluble CR1 in complement- and neutrophil-mediated tissue injury.

Complement activation is an important step for triggering of acute inflammatory reactions. Soluble human recombinant complement receptor type 1 (sCR1) blocks complement activation by both classical and alternative pathways. In addition to glycogen-induced peritonitis, three models of complement-dependent acute inflammatory injury have been used to assess the protective effects of sCR1: lung and dermal injury after intraalveolar or intradermal deposition of IgG immune complexes; acute lung injury resulting from intravascular activation of complement after the i.v. injection of cobra venom factor; and acute skin and lung injury (at 4 h) after thermal trauma involving 25 to 30% total body surface area. Vascular injury was quantified by increases in vascular permeability, hemorrhage, neutrophil infiltration, and, as indicated, tissue water content. Intravenous infusion of sCR1 reduced lung and dermal vascular injury in all models studied. In glycogen-induced peritoneal exudates sCR1-reduced neutrophil accumulation by 79%. In animals undergoing IgG immune complex-induced alveolitis, sCR1 treatment reduced vascular permeability and hemorrhage by 72 and 71%, respectively, and tissue accumulation of neutrophils was reduced by 68%. After cobra venom factor injection, sCR1 reduced increases in lung vascular permeability by 67%, hemorrhage by 73%, and lung myeloperoxidase content by 55%. Four hours after thermal injury of skin, sCR1-treated animals demonstrated significant protection against lung injury; increases in vascular permeability and hemorrhage were reduced by 45 and 46%, respectively, and myeloperoxidase content was lowered by 39%. In thermal injury of the skin, sCR1 injection reduced dermal vascular permeability by 25% at 1 h (p = NS) and 44% at 4 h. Water content in skin biopsies was also decreased. There was a dose-response relationship between the amount of sCR1 infused and the extent of protection in each of the injury models. These data demonstrate that sCR1 offers significant protection against complement-dependent tissue injury in the animal models studied and that the protective effects are related to reduced neutrophil content.     

Construction and properties of replication-competent murine retroviral vectors encoding methotrexate resistance.

A series of replication-competent Moloney murine leukemia virus vectors was constructed in which each vector contained a mutant dihydrofolate reductase (DHFR) cDNA insert in the U3 region of the viral long terminal repeat. Two of the resulting viruses, MLV (murine leukemia virus) DHFR*-5 and MLV DHFR*-7, were able to stably transfer methotrexate resistance to infected fibroblast cells upon multiple rounds of virus replication and in the absence of drug selection. Cell lines producing recombinant virus with high titers were established, which indicated that the insert did not grossly interfere with viral replication functions. These vectors should be useful for introducing and expressing foreign genes in vivo in tissues and whole animals in which virus spread is needed for efficient infection.     

The Arabidopsis MALE STERILITY 2 protein shares similarity with reductases in elongation/condensation complexes

The Arabidopsis thaliana MALE STERILITY 2 ( MS2 ) gene product is involved in male gametogenesis. The first abnormalities in pollen development of ms2 mutants are seen at the stage in microsporogenesis when microspores are released from tetrads. Expression of the MS2 gene is observed in tapetum of wild-type flowers at, and shortly after, the release of microspores from tetrads. The MS2 promoter controls GUS expression at a comparable stage in the tapetum of transgenic tobacco containing an MS2 promoter–GUS fusion. The occasional pollen grains produced by mutant ms2 plants have very thin pollen walls. They are also sensitive to acetolysis treatment, which is a test for the presence of an exine layer. The MS2 gene product shows sequence similarity to a jojoba protein that converts wax fatty acids to fatty alcohols. A possible function of the MS2 protein as a fatty acyl reductase in the formation of pollen wall substances is discussed.     

Potential role of monocyte chemoattractant protein 1/JE in monocyte/macrophage-dependent IgA immune complex alveolitis in the rat.

We have examined the role of monocyte chemoattractant protein 1 (MCP 1) in the pathogenesis of monocyte/macrophage-dependent IgA immune complex alveolitis in the rat. Rat MCP 1 was cloned and expressed in order to facilitate analysis of its function in rat models of human disease. A cDNA library was constructed from rat pulmonary artery endothelial cells stimulated with TNF-alpha. The cDNA library was screened with synthetic oligonucleotide probes based on the recently published rat MCP 1 cDNA sequence. Among numerous MCP 1-positive clones, four full length (approximately 480 bp) cDNA were rescued, amplified by polymerase chain reaction, and ligated into a pJVETLZ baculovirus transfer vector. Spodoptera frugiperda insect cells (Sf-21) infected with baculovirus recombinants (Auto-grapha california nuclear polyhedrosis virus) bearing properly oriented MCP 1 cDNA (AcMCP 1) directed the expression of unique peptides of 18, 21, and 23 kDa. Treatment of AcMCP 1-infected Sf-21 cells with tunicamycin resulted in reduced production of the 21- and 23-kDa proteins and an increase in 16- to 18-kDa products, the predicted size range of uncleaved and nonglycosylated rat MCP 1. Denatured and refolded 23-kDa and 21-kDa rat MCP 1 species exhibited dose-dependent monocyte-specific chemotactic activity at concentrations as low as 10(-10) M whereas the 18-kDa species exhibited negligible activity. Antibodies that react with the immunoblot, block rat rMCP 1-directed monocyte chemotaxis, and neutralize monocyte-specific chemotactic activity secreted by TNF-stimulated rat endothelial cells were raised in rabbits immunized with the 23-kDa MCP 1 species. Intravenous administration of anti-MCP 1 antibodies upon initiation of IgA immune complex lung injury resulted in a marked reduction in lung injury as measured by pulmonary vascular permeability, alveolar hemorrhage, and pulmonary monocyte/macrophage recruitment and pulmonary monocyte/macrophage recruitment. These data suggest that MCP 1 may play an important role in the pathogenesis of monocyte/macrophage-dependent IgA immune complex alveolitis in the rat.