The biochemical relationships in anaerobic digestion after thermal hydrolysis at Davyhulme

The commissioning of the largest thermal hydrolysis plant in the world at Davyhulme, Manchester involved detailed analysis of the digestion process. The plant consists of eight digesters, 20 thermal hydrolysis reactors and a maximum throughput of 121 000 tDS/year. The plant was converted from conventional digestion with a loading rate of 1.25 kgVS/m³/day to digestion fed with thermally hydrolysed sludge with a loading rate of 4.16 kgVS/m³/day. At the start of the commissioning and ramp‐up of the loading rate, control actions were based on acid/alkalinity, pH and foaming; however, it was found that the methane concentration was the parameter that changed quickest during digester instability. The monitoring was changed during commissioning to use methane concentration as the primary control parameter. It was found that the rate of increased organic loading is dependent on the availability of seed biomass already acclimatised to thermally hydrolysed feed sludge and the presence of a high alkalinity buffer.     

Stimuli-responsive releasing of gold nanoparticles and liposomes from aptamer-functionalized hydrogels

Controlled release of therapeutic agents is important for improving drug efficacy and reducing toxicity. Recently, hydrogels have been used for controlled release applications. While the majority of the previous work focused on releasing the cargo in response to physical stimuli such as temperature, light, electric field, and pH, we aim to trigger cargo release in the presence of small metabolites. In our system a DNA aptamer that can bind to adenosine, AMP, and ATP was used as a linker to attach either DNA-functionalized gold nanoparticles or liposomes to DNA-functionalized hydrogels. In the presence of the metabolite, both the nanoparticle and liposome cargos were released. The effect of salt, temperature, target concentration, and drying has been systematically studied. Interestingly, we found that the gel can be completely dried while retaining the DNA linkages and adenosine induced release was still achieved after rehydration. Our work demonstrates that aptamers can be used to control the release of drugs and other materials attached to hydrogels.     

Application of ozone for enhancing the microbiological safety and quality of foods: a review.

Ozone (O3) is a strong antimicrobial agent with numerous potential applications in the food industry. High reactivity, penetrability, and spontaneous decomposition to a nontoxic product (i.e., O2) make ozone a viable disinfectant for ensuring the microbiological safety of food products. Ozone has been used for decades in many countries and recently, the generally recognized as safe (GRAS) status of this gas has been reaffirmed in the United States. Ozone, in the gaseous or aqueous phases, is effective against the majority of microorganisms tested by numerous research groups. Relatively low concentrations of ozone and short contact time are sufficient to inactivate bacteria, molds, yeasts, parasites, and viruses. However, rates of inactivation are greater in ozone demand-free systems than when the medium contains oxidizable organic substances. Susceptibility of microorganisms to ozone also varies with the physiological state of the culture, pH of the medium, temperature, humidity, and presence of additives (e.g., acids, surfactants, and sugars). Ozone applications in the food industry are mostly related to decontamination of product surface and water treatment. Ozone has been used with mixed success to inactivate contaminant microflora on meat, poultry, eggs, fish, fruits, vegetables, and dry foods. The gas also is useful in detoxification and elimination of mycotoxins and pesticide residues from some agricultural products. Excessive use of ozone, however, may cause oxidation of some ingredients on food surface. This usually results in discoloration and deterioration of food flavor. Additional research is needed to elucidate the kinetics and mechanisms of microbial inactivation by ozone and to optimize its use in food applications.     

Deletion of cell division cycle 2-like 1 gene locus on 1p36 in non-Hodgkin lymphoma

Our laboratories have documented a significantly high occurrence of chromosome 1p36 rearrangements in non-Hodgkin lymphoma (NHL). The cell division cycle 2-like 1(CDC2L1) (also known as TP58 or PITSLRE) gene, a protein kinase implicated in apoptotic signaling, is located at the very distal region of chromosome 1p36 and is likely to be disrupted by structural rearrangements involving 1p36. To determine the molecular consequences of the recurrent involvement of the 1p36 region, we examined metaphases containing 1p36 abnormalities from 31 specimens derived from 26 patients for the possible deletion of CDC2L1 by fluorescence in situ hybridization (FISH) using the TP58clk-1 DNA probe. Twenty-three cases exhibited the loss of CDC2L1 from the abnormal chromosome 1. In 2 of 26 cases, the gene locus was translocated to the partner chromosome, and in four specimens, all derived from one case, CDC2L1 was not deleted. This pilot investigation suggests that 1p36 rearrangements, and consequently the loss of the CDC2L1 gene locus, is important in NHL. This work also opens avenues for further molecular studies and prognostic correlations.     

Fundamentals of MRAM Technology

Developments in portable communication and computing systems are creating a growing demand for nonvolatile random access memory that is dense and fast. None of the existing solid-state memories can provide all the needed attributes in a single memory solution. Therefore, to achieve the required multiple functionality requirements, a number of different memories are being used while compromising performance and adding cost to the system. Magnetoresistive Random Access Memory (MRAM) has the potential to replace these memories in various systems with a single, universal memory solution. Key attributes of MRAM technology are nonvolatility and unlimited read and write endurance. In addition, MRAM can operate at high-speed and is expected to have competitive densities. In this paper we describe several fundamental technical and scientific aspects of MRAM with emphasis on recent accomplishments that enabled our successful demonstration of a 256 kbit memory chip.     

Effect of essential fatty acid depletion on tissue phospholipid fatty acids in spontaneously hypertensive and normotensive rats

Weanling male spontaneously hypertensive (SHR) and normotensive (WKY) rats were maintained on a fat-free semisynthetic diet and killed at various intervals. The effects of fat-depletion on the appearance of essential fatty acid (EFA) deficiency symptoms, the progressive changes of major fatty acids in plasma, liver, heart, and kidney phospholipids (PL), and in skin total lipids were compared between these two strains. After five weeks on the diet, the slower growth and the appearance of EFA deficiency symptoms became evident in SHR. In general, fat-depletion reduced the levels of n−6 fatty acids, whereas it increased those of 20∶3n−9. However, the fat-depletion induced reduction of 18∶2n−6 in heart PL and 20∶4n−6 in kidney, while the elevation of 20∶3n−9 in plasma, heart, and kidney PL were greater in WKY than in SHR. As a result, the elevation of biochemical EFA deficiency index—20∶3n−9/20∶4n−6 ratio—was greater in WKY than in SHR. In comparison with WKY, the concentrations of liver triacylglycerols and the weights of adipose tissues in SHR were reduced to a greater extent, indicating an active catabolism of triacylglycerols in SHR. This study suggests that the earlier appearance of morphological symptoms of EFA deficiency in SHR was not associated with the reducing n−6 EFA levels or with an elevation of triene/tetraene ratio, but possibly to a reduced supply of n−6 EFA for skin prostaglandin synthesis.     

Ethnography,ethnomethodology and the problem of generalisation in design

This paper discusses the relationship between sociological theory and method, ethnomethodology and design. It argues that social science theoretical and methodological interests cannot form a basis for interdisciplinarity. Much of the argument about the relevance of ethnography for design, and more specifically about ethnomethodological enquiry, has been cast firstly as problems of method and secondly in terms of the problem of generalisation. We argue that in both instances the problem is miscast. Drawing on the arguments of Wittgenstein and Winch, we suggest that forms of generalisation are to be found in ethnomethodological enquiry and that they may be useful in design-related enquiry. We further suggest, however, that they are not the forms to be found in explanatory social science.     

Social ties: Subgroup differences in costs and benefits.

Studied social support in response to stressful life events (i.e., whether social ties are stressful as well as supportive and whether there are subgroup differences in the efficacy of social support) among 314 women (mean age 34.7 yrs) with a mean educational level of 10.7 yrs and a mean family income of $7,500–20,000/yr. Ss completed measures of negative affect, perceived stressfulness of life events of significant others, and social support. Selected findings show that (1) the mobilization of social support was associated with better psychological well-being for Ss with greater personal resources; (2) Ss with lower levels of personal resources were more distressed by life events in the lives of their significant others, especially as the number of these events increased; and (3) subgroup effects of interpersonal support and stress on psychological well-being were independent and separate. It is concluded that Ss with greater material and psychological resources derived more beneficial support and suffered less stress from their social ties. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)