972 resultados para ESSENTIAL SPECTRUM OF SEMIGROUP


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Bipolar disorder (BP) is among the top ten most disabling illnesses worldwide. This review includes findings from recent studies employing functional neuroimaging to examine functional abnormalities in neural systems underlying core domains of the psychopathology in BP: emotion processing, emotion regulation and executive control, and common comorbid features of BP, that are relevant to the wide spectrum of BP rather than focused on the more traditional BPI subtype, and that may facilitate future identification of diagnostically-relevant biomarkers of the disorder. In addition, an emerging number of studies are reviewed that demonstrate the use of neuroimaging to elucidate biomarkers whose identification may help to (1) identify at-risk individuals who will subsequently develop the illness to facilitate early intervention, (2) identify targets for treatment and markers of treatment response. The use of newer neuroimaging techniques and potential confounds of psychotropic medication upon neuroimaging findings in BP are also examined. These approaches will help to improve diagnosis and the mental well-being of all individuals with BP.

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Background: A natural glycoprotein usually exists as a spectrum of glycosylated forms, where each protein molecule may be associated with an array of oligosaccharide structures. The overall range of glycoforms can have a variety of different biophysical and biochemical properties, although details of structure–function relationships are poorly understood, because of the microheterogeneity of biological samples. Hence, there is clearly a need for synthetic methods that give access to natural and unnatural homogeneously glycosylated proteins. The synthesis of novel glycoproteins through the selective reaction of glycosyl iodoacetamides with the thiol groups of cysteine residues, placed by site-directed mutagenesis at desired glycosylation sites has been developed. This provides a general method for the synthesis of homogeneously glycosylated proteins that carry saccharide side chains at natural or unnatural glycosylation sites. Here, we have shown that the approach can be applied to the glycoprotein hormone erythropoietin, an important therapeutic glycoprotein with three sites of N-glycosylation that are essential for in vivo biological activity. Results: Wild-type recombinant erythropoietin and three mutants in which glycosylation site asparagine residues had been changed to cysteines (His10-WThEPO, His10-Asn24Cys, His10-Asn38Cys, His10-Asn83CyshEPO) were overexpressed and purified in yields of 13 mg l−1 from Escherichia coli. Chemical glycosylation with glycosyl-β-N-iodoacetamides could be monitored by electrospray MS. Both in the wild-type and in the mutant proteins, the potential side reaction of the other four cysteine residues (all involved in disulfide bonds) were not observed. Yield of glycosylation was generally about 50% and purification of glycosylated protein from non-glycosylated protein was readily carried out using lectin affinity chromatography. Dynamic light scattering analysis of the purified glycoproteins suggested that the glycoforms produced were monomeric and folded identically to the wild-type protein. Conclusions: Erythropoietin expressed in E. coli bearing specific Asn→Cys mutations at natural glycosylation sites can be glycosylated using β-N-glycosyl iodoacetamides even in the presence of two disulfide bonds. The findings provide the basis for further elaboration of the glycan structures and development of this general methodology for the synthesis of semi-synthetic glycoproteins. Results: Wild-type recombinant erythropoietin and three mutants in which glycosylation site asparagine residues had been changed to cysteines (His10-WThEPO, His10-Asn24Cys, His10-Asn38Cys, His10-Asn83CyshEPO) were overexpressed and purified in yields of 13 mg l−1 from Escherichia coli. Chemical glycosylation with glycosyl-β-N-iodoacetamides could be monitored by electrospray MS. Both in the wild-type and in the mutant proteins, the potential side reaction of the other four cysteine residues (all involved in disulfide bonds) were not observed. Yield of glycosylation was generally about 50% and purification of glycosylated protein from non-glycosylated protein was readily carried out using lectin affinity chromatography. Dynamic light scattering analysis of the purified glycoproteins suggested that the glycoforms produced were monomeric and folded identically to the wild-type protein. Conclusions: Erythropoietin expressed in E. coli bearing specific Asn→Cys mutations at natural glycosylation sites can be glycosylated using β-N-glycosyl iodoacetamides even in the presence of two disulfide bonds. The findings provide the basis for further elaboration of the glycan structures and development of this general methodology for the synthesis of semi-synthetic glycoproteins

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2000 Mathematics Subject Classification: 47A10, 47A13.

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2010 Mathematics Subject Classification: 47A10.

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Antibiotic resistance, production of alginate and virulence factors, and altered host immune responses are the hallmarks of chronic Pseudomonas aeruginosa infection. Failure of antibiotic therapy has been attributed to the emergence of P. aeruginosa strains that produce β-lactamase constitutively. In Enterobacteriaceae, β-lactamase induction involves four genes with known functions: ampC, ampR, ampD, and ampG, encoding the enzyme, transcriptional regulator, amidase and permease, respectively. In addition to all these amp genes, P. aeruginosa possesses two ampG paralogs, designated ampG and ampP. In this study, P. aeruginosa ampC, ampR, ampG and ampP were analyzed. Inactivation of ampC in the prototypic PAO1 failed to abolish the β-lactamase activity leading to the discovery of P. aeruginosa oxacillinase PoxB. Cloning and expression of poxB in Escherichia coli confers β-lactam resistance. Both AmpC and PoxB contribute to P. aeruginosa resistance against a wide spectrum of β-lactam antibiotics. The expression of PoxB and AmpC is regulated by a LysR-type transcriptional regulator AmpR that up-regulates AmpC but down-regulates PoxB activities. Analyses of P. aeruginosa ampR mutant demonstrate that AmpR is a global regulator that modulates the expressions of Las and Rhl quorum sensing (QS) systems, and the production of pyocyanin, LasA protease and LasB elastase. Introduction of the ampR mutation into an alginate-producing strain reveals the presence of a complex co-regulatory network between antibiotic resistance, QS alginate and other virulence factor production. Using phoA and lacZ protein fusion analyses, AmpR, AmpG and AmpP were localized to the inner membrane with one, 16 and 10 transmembrane helices, respectively. AmpR has a cytoplasmic DNA-binding and a periplasmic substrate binding domains. AmpG and AmpP are essential for the maximal expression of β-lactamase. Analysis of the murein breakdown products suggests that AmpG exports UDP-N-acetylmuramyl-L-alanine-γ-D-glutamate-meso-diaminopimelic acid-D-alanine-D-alanine (UDP-MurNAc-pentapeptide), the corepressor of AmpR, whereas AmpP imports N-acetylglucosaminyl-beta-1,4-anhydro-N-acetylmuramic acid-Ala-γ-D-Glu-meso-diaminopimelic acid (GlcNAc-anhMurNAc-tripeptide) and GlcNAc-anhMurNAc-pentapeptide, the co-inducers of AmpR. This study reveals a complex interaction between the Amp proteins and murein breakdown products involved in P. aeruginosa β-lactamase induction. In summary, this dissertation takes us a little closer to understanding the P. aeruginosa complex co-regulatory mechanism in the development of β-lactam resistance and establishment of chronic infection. ^

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Chloroperoxidase (CPO) is the most versatile heme-containing enzyme that catalyzes a broad spectrum of reactions. The remarkable feature of this enzyme is the high regio- and enantio-selectivity exhibited in CPO-catalyzed oxidation reactions. The aim of this dissertation is to elucidate the structural basis for regio- and enantio-selective transformations and investigate the application of CPO in biodegradation of synthetic dyes. ^ To unravel the mechanism of CPO-catalyzed regioselective oxidation of indole, the dissertation explored the structure of CPO-indole complex using paramagnetic relaxation and molecular modeling. The distances between the protons of indole and the heme iron revealed that the pyrrole ring of indole is oriented toward the heme with its 2-H pointing directly at the heme iron. This provides the first experimental and theoretical explanation for the "unexpected" regioselectivity of CPO-catalyzed indole oxidation. Furthermore, the residues including Leu 70, Phe 103, Ile 179, Val 182, Glu 183, and Phe 186 were found essential to the substrate binding to CPO. These results will serve as a lighthouse in guiding the design of CPO mutants with tailor-made activities for biotechnological applications. ^ To understand the origin of the enantioselectivity of CPO-catalyzed oxidation reactions, the interactions of CPO with substrates such as 2-(methylthio)thiophene were investigated by nuclear magnetic resonance spectroscopy (NMR) and computational techniques. In particular, the enantioselectivity is partly explained by the binding orientation of substrates. In third facet of this dissertation, a green and efficient system for degradation of synthetic dyes was developed. Several commercial dyes such as orange G were tested in the CPO-H2O 2-Cl- system, where degradation of these dyes was found very efficient. The presence of halide ions and acidic pH were found necessary to the decomposition of dyes. Significantly, the results revealed that this degradation of azo dyes involves a ferric hypochlorite intermediate of CPO (Fe-OCl), compound X.^

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The abuse of antibiotics and the emergence of multi-drug resistant bacterial strains have created the need to explore alternative methods of controlling microbial pathogens. The bacteriocin family of antimicrobial peptides has been proposed as one such alternative to classic antibiotics. Nisin A belongs to the subgroup of bacteriocins called the lantibiotics, which contain several unusual amino acids as a consequence of enzyme-mediated post-translational modifications. As nisin is produced by generally regarded as safe (GRAS) microorganisms, it could potentially be applied in a clinical setting. However, as lantibiotics are naturally produced in such small quantities, this can hinder their industrial potential. In order to overcome this, several approaches can be utilised. For example, given the gene encoded nature of lantibiotics, genetic engineering approaches can be implemented in order to yield variants with enhanced properties. Here, the use of mutagenesis-based strategies was employed to obtain a derivative of nisin with enhanced bioactivity in vitro. Investigations with purified peptide highlighted the enhanced specific activity of this variant, nisin M21V, against food-borne Listeria monocytogenes strains. Furthermore, this specific enhanced bioactivity was evident in a mouse model of listeriosis. Reductions in bioluminescence and microbial counts in organs from infected mice were observed following treatment with nisin M21V compared to that of wild-type nisin A. Peptide bioengineering approaches were also implemented to obtain additional novel derivatives of nisin. The generation of “S5X” and “S33X” banks (representing a change of natural serines at positions 5 and 33 to all possible alternative residues) by a combination of site-saturation and site-directed mutagenesis led to the identification of several derivatives exhibiting improved stability. This allowed the rational design of variants with enhanced stability compared to that of wild type nisin. Another means of tackling issues associated with lantibiotic yield is to combine lantibiotics with other antimicrobials. This could circumvent the need for enhanced production while also reducing concentrations of the peptide antimicrobials. We observed that combinations of nisin variants and low levels of plant essential oils (thymol, carvacrol, trans-cinnamaldehyde) significantly controlled Gram negative foodborne pathogens in in vitro assays compared to nisin A-essential oil combinations. This enhanced control was also evident in model food systems. Nisin variants used in conjunction with carvacrol significantly reduced numbers of E. coli O157:H7 in apple juice while a commercial nisin preparation used in combination with citric acid significantly controlled C. sakazakii in infant milk formula. It is noteworthy that while nisin is generally associated with Gram positive targets, upon combination with plant essential oils the spectrum of inhibition was broadened to Gram negative targets.

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A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf A Minimum Essential Standard of Living (MESL) is derived from a negotiated consensus on what people believe is a minimum standard. It is a standard of living that meets an individual’s or a household’s physical, psychological and social needs. This is calculated by identifying the goods and services required by different household types in order to meet their needs. While an MESL is based on needs, not wants, it is a standard of living below which nobody should be expected to live. This report focuses on food, one of the 16 elements of the Minimum Essential Standard of Living (MESL) data. It is based on a methodology called Consensual Budget Standards (CBS). The report is presented in the context of increasing concerns about the issue of food poverty in the Republic of Ireland (ROI) and an increase in the number of people reporting that they do not have enough money to buy food. Recent data from The Organisation for Economic Co-operation and Development (OECD) have shown that the number of people believing they cannot afford food doubled from 4.2% in 2008 to 9% in 2014. Data from Eurostat show that in 2013, food and non-alcoholic beverage prices in Ireland were 17% higher than the EU average. Moreover, research by Carney and Maitre, using data from the Survey on Income and Living Conditions (SILC), found that one in ten people are living in food poverty in Ireland. Food poverty is defined as the inability to have an adequate and nutritious diet due to issues of affordability and access to food. This has related effects on health, culture and social participation. The 2013 data from the Survey on Income and Living Conditions (SILC) show that 1.4 million people, almost 31% of the population, suffer from deprivation. This means that they are unable to afford two items from a list of 11 very basic items (of which one is not being able to eat a meal with meat, chicken, fish or a vegetarian equivalent every second day). The highest levels of deprivation are experienced by lone parents (63%), unemployed people (55%) and people not at work because of illness or disability (53%). The experience of the Vincentian Partnership for Social Justice (VPSJ) is that expenditure on food tends to be one of the least important considerations when households are dealing with competing demands on an inadequate income. - See more at: http://www.safefood.eu/Publications/Research-reports/The-cost-of-a-healthy-food-basket.aspx#sthash.RiBpj5no.dpuf

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BACKGROUND: Surgical conditions represent a significant proportion of the global burden of disease, and therefore, surgery is an essential component of health systems. Achieving universal health coverage requires effective monitoring of access to surgery. However, there is no widely accepted standard for the required capabilities of a first-level hospital. We aimed to determine whether a group of operations could be used to describe the delivery of essential surgical care.

METHODS: We convened an expert panel to identify procedures that might indicate the presence of resources needed to treat an appropriate range of surgical conditions at first-level hospitals. Using data from the World Health Organization Emergency and Essential Surgical Care Global database, collected using the WHO Situational Analysis Tool (SAT), we analysed whether the ability to perform each of these procedures-which we term "bellwether procedures"-was associated with performing a full range of essential surgical procedures.

FINDINGS: The ability to perform caesarean delivery, laparotomy, and treatment of open fracture was closely associated with performing all obstetric, general, basic, emergency, and orthopaedic procedures (p < 0.001) in the population that responded to the WHO SAT Survey. Procedures including cleft lip, cataract, and neonatal surgery did not correlate with performing the bellwether procedures.

INTERPRETATION: Caesarean delivery, laparotomy, and treatment of open fractures should be standard procedures performed at first-level hospitals. With further validation in other populations, local managers and health ministries may find this useful as a benchmark for what first-level hospitals can and should be able to perform on a 24/7 basis in order to ensure delivery of emergency and essential surgical care to their population. Those procedures which did not correlate with the bellwether procedures can be referred to a specialized centre or collected for treatment by a visiting specialist team.

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Chloroperoxidase (CPO) is the most versatile heme-containing enzyme that catalyzes a broad spectrum of reactions. The remarkable feature of this enzyme is the high regio- and enantio-selectivity exhibited in CPO-catalyzed oxidation reactions. The aim of this dissertation is to elucidate the structural basis for regio- and enantio-selective transformations and investigate the application of CPO in biodegradation of synthetic dyes. To unravel the mechanism of CPO-catalyzed regioselective oxidation of indole, the dissertation explored the structure of CPO-indole complex using paramagnetic relaxation and molecular modeling. The distances between the protons of indole and the heme iron revealed that the pyrrole ring of indole is oriented toward the heme with its 2-H pointing directly at the heme iron. This provides the first experimental and theoretical explanation for the "unexpected" regioselectivity of CPO-catalyzed indole oxidation. Furthermore, the residues including Leu 70, Phe 103, Ile 179, Val 182, Glu 183, and Phe 186 were found essential to the substrate binding to CPO. These results will serve as a lighthouse in guiding the design of CPO mutants with tailor-made activities for biotechnological applications. To understand the origin of the enantioselectivity of CPO-catalyzed oxidation reactions, the interactions of CPO with substrates such as 2-(methylthio)thiophene were investigated by nuclear magnetic resonance spectroscopy (NMR) and computational techniques. In particular, the enantioselectivity is partly explained by the binding orientation of substrates. In third facet of this dissertation, a green and efficient system for degradation of synthetic dyes was developed. Several commercial dyes such as orange G were tested in the CPO-H2O2-Cl- system, where degradation of these dyes was found very efficient. The presence of halide ions and acidic pH were found necessary to the decomposition of dyes. Significantly, the results revealed that this degradation of azo dyes involves a ferric hypochlorite intermediate of CPO (Fe-OCl), compound X.

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Plants of genus Schinus are native South America and introduced in Mediterranean countries, a long time ago. Some Schinus species have been used in folk medicine, and Essential Oils of Schinus spp. (EOs) have been reported as having antimicrobial, anti-tumoural and anti-inflammatory properties. Such assets are related with the EOs chemical composition that depends largely on the species, the geographic and climatic region, and on the part of the plants used. Considering the difficulty to infer the pharmacological properties of EOs of Schinus species without a hard experimental setting, this work will focus on the development of an Artificial Intelligence grounded Decision Support System to predict pharmacological properties of Schinus EOs. The computational framework was built on top of a Logic Programming Case Base approach to knowledge representation and reasoning, which caters to the handling of incomplete, unknown, or even self-contradictory information. New clustering methods centered on an analysis of attribute’s similarities were used to distinguish and aggregate historical data according to the context under which it was added to the Case Base, therefore enhancing the prediction process.

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The objective of the present work was to develop stategies for raising the shelf-life of red raspberries (Rubus idaeus L.). The quality of red raspberries over shelf-life after coated with alginate plus Brazilian Citrus essential oils was evaluated. Edible coatings did not significantly influence the firmness loss, soluble solids content (SCC), and brightness of fruits over time, when compared to control, nevertheless all edible coatings with essential oils induced higher weight loss than those samples in which the essential oils were not incorporated. Fruits coated with alginate plus lime essential oil (0.2%) or orange essential oil (0.1%) after 15 days of storage had less red skin, but were darker than the remaining samples. The less red colour verified in these samples was also coincident with the lower concentration of anthocyanins at the end of the experiment as well as the lower capacity for scavenging ABTS free radicals or quenching singlet oxygen. The edible coatings supplemented with the essential oil of orange either at 0.1 % or 0.2 % were very efficient to control the yeasts and moulds growth after 15 days of storage. To control the development of aerobic mesophilic bacteria the use of essential oil of lemon 0.2% and essential oil of orange 0.1% were the most efficient. The essential oils used in the edible coatings did not significantly change the sensorial properties of the fruit. Cyanidin-3-O-sophoroside, cyanidin-3-O-glucosylrutinoside, cyanidin-3-O-xylosylrutinoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, pelargonidin-3-O-sophoroside, pelargonidin-3-O-glucosylrutinoside, pelargonidin 3-O-glucoside, pelargonidin 3-O-rutinoside were found in raspberries fruits. An unknown cyanidin derivative was also found in all samples, constituting 27.4% of total anthocyanin content.

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The Raman spectrum of holmquistite, a Li-containing orthorhombic amphibole from Bessemer City, USA has been measured. The OH-stretching region is characterized by bands at 3661, 3646, 3634 and 3614 cm–1 assigned to 3 Mg–OH, 2 Mg + Fe2+–OH, Mg + 2Fe2+–OH and 3 Fe2+–OH, respectively. These Mg and Fe2+ cations are located at the M1 and M3 sites and have a Fe2+/(Fe2+ + Mg) ratio of 0.35. The 960–1110 cm–1 region represents the antisymmetric Si–O–Si and O–Si–O stretching vibrations. For holmquistite, strong bands are observed around 1022 and 1085 cm–1 with a shoulder at 1127 cm–1 and minor bands at 1045 and 1102 cm–1. In the region 650–800 cm–1 bands are observed at 679, 753 and 791 cm–1 with a minor band around 694 cm–1 attributed to the symmetrical Si–O–Si and Si–O vibrations. The region below 625 cm–1 is characterized by 14 vibrations related to the deformation modes of the silicate double chain and vibrations involving Mg, Fe, Al and Li in the various M sites. The 502 cm–1 band is a Li–O deformation mode while the 456, 551 and 565 cm–1 bands are Al–O deformation modes.

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In Apriaden Pty Ltd v Seacrest Pty Ltd the Victorian Court of Appeal decided that termination of a lease under common law contractual principles following repudiation is an alternative to reliance upon an express forfeiture provision in the lease and that it is outside the sphere of statutory protections given against the enforcing of a forfeiture. The balance of authority supports the first aspect of the decision. This article focuses on the second aspect of it, which is a significant development in the law of leases. The article considers the implications of this decision for essential terms of clauses in leases, argues that common law termination for breach of essential terms should be subject to compliance with these statutory requirements and, as an alternative, suggests a way forward through appropriate law reform, considering whether the recent Victorian reform goes far enough.