917 resultados para New Orleans Public Library


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Christoph Franz of Lufthansa recently identified Ryanair, easyJet, Air Berlin and Emirates as the company’s main competitors – gone are the days when it could benchmark itself against BA or Air France-KLM! This paper probes behind the headlines to assess the extent to which different airlines are in competition, using evidence from the UK and mainland European markets. The issue of route versus network competition is addressed. Many regulators have put an emphasis on the former whereas the latter, although less obvious, can be more relevant. For example, BA and American will cease to compete between London and Dallas Fort Worth if their alliance obtains anti-trust immunity but 80% of the passengers on this route are connecting at one or both ends and hence arguably belong to different markets (e.g. London-San Francisco, Zurich-Dallas, Edinburgh-New Orleans) which may be highly contested. The remaining 20% of local traffic is actually insufficient to support a single point to point service in its own right. Estimates are made of the seat capacity major airlines are offering to the local market as distinct from feeding other routes. On a sector such as Manchester–Amsterdam, 60% of KLM’s passengers are transferring at Schiphol as against only 1% of bmibaby’s. Thus although KLM operates 5 flights and 630 seats per day against bmibaby’s 2 flights and 298 seats, in the point to point market bmibaby offers more seats than KLM. The growth of the Low Cost Carriers (LCCs) means that competition increasingly needs to be viewed on city pair markets (e.g. London-Rome) rather than airport pair markets (e.g. Heathrow-Fiumicino). As the stronger LCCs drive out weaker rivals and mainline carriers retrench to their major hubs, some markets now have fewer direct options than existed prior to the low cost boom. Timings and frequencies are considered, in particular the extent to which services are a true alternative especially for business travellers. LCCs typically offer lower frequencies and more unsociable timings (e.g. late evening arrivals at remote airports) as they are more focused on providing the cheapest service rather than the most convenient schedule. Interesting findings on ‘monopoly’ services are presented (including alliances) - certain airlines have many more of these than others. Lufthansa has a significant number of sectors to itself whereas at the other extreme British Airways has direct competition on almost every route in its network. Ryanair and flybe have a higher proportion of monopoly routes than easyJet or Air Berlin. In the domestic US market it has become apparent since deregulation that better financial returns can come from dominating a large number of smaller markets rather than being heavily exposed in the major markets - which are hotly fought over. Regional niches that appear too thin for Ryanair to serve (with its all 189 seat 737-800 fleet) are identified. Fare comparisons in contrasting markets provide some insights to marketing and pricing strategies. Data sources used include OAG (schedules and capacity), AEA (traditional European airlines traffic by region), the UK CAA (airport, airline and route traffic plus survey information of passenger types) and ICAO (international route traffic and capacity by carrier). It is concluded that airlines often have different competitors depending on the context but in surprisingly many cases there are actually few or no direct substitutes. The competitive process set in train by deregulation of European air services in the 1990s is leading back to one of natural monopolies and oblique alternatives. It is the names of the main participants that have changed however!

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D. João de Magalhães e Avelar (1754-1833) formou aquela que, ao tempo, era a maior biblioteca privada portuguesa. Com cerca de 36000 volumes, foi elogiada por personalidades nacionais e estrangeiras, por aliar à quantidade de volumes inúmeros e valiosíssimos manuscritos. Formada ao longo dos séculos XVIII e XIX, durante mais de 30 anos, originou, em 1833, o primeiro núcleo da actual Biblioteca Pública Municipal do Porto. Numa época em que possuir livros era sinónimo de prestígio social mas num período em que quase não havia tradição de bibliotecas públicas no nosso país, contrariamente ao que acontecia noutras realidades, a livraria privada de Avelar formou, com outras, a Real Biblioteca Pública da Cidade do Porto. Em 1833, aquando do primeiro aniversário da entrada do exército liberal no Porto, por decreto, criou-se a biblioteca portuense. Estabelecida na casa que servia de Hospício dos Religiosos de Santo António do Val da Piedade, à praça da Cordoaria, tinha como objectivo satisfazer a utilidade pública, estando aberta todos os dias, excepto domingos e feriados. Propriedade da cidade do Porto, ficava sujeita à administração da Câmara que se obrigava à sua guarda, manutenção, conservação, bem como à constante aquisição de espólio. Como veremos, tratou-se de um processo conflituoso mas o Porto obtinha, definitivamente, a sua biblioteca pública.

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Este trabalho de investigação assenta num estudo comparativo da realidade das Bibliotecas Escolares e das Bibliotecas Públicas, procurando quer os pontos de contacto, quer as divergências entre ambas. No âmbito da nova filosofia de edificação das bibliotecas construídas pela empresa pública Parque Escolar, EPE, prevê-se a implantação das mesmas junto à entrada das escolas, de forma a servir não só a população escolar, sua principal razão de ser, mas também facilitar a abertura à comunidade. Tendo em conta este duplo papel das bibliotecas, foram analisadas as implicações ao nível da Selecção, do Tratamento e da Difusão da Informação nas mesmas, bem como as políticas de funcionamento e os recursos humanos que a situação exige. O estudo desta nova realidade faz-se a partir da análise dos dois casos concretos de Bibliotecas Escolares duais, em funcionamento efectivo, em Portugal. Complementarmente, são também objecto de análise as directrizes nacionais e internacionais que sustentam o funcionamento das Bibliotecas Escolares e das Bibliotecas Públicas, procedendo-se ainda à investigação da existência deste tipo de realidade a nível internacional, como ponto de partida para comparativamente analisar a situação portuguesa, face à realidade internacional. A identificação de pontos fortes e de pontos fracos a nível nacional e internacional, permite perceber as implicações que esta política organizacional pressupõe, quer para os seus utilizadores, quer para os professores bibliotecários, quer para o eficaz funcionamento destas bibliotecas, que procuram cumprir um duplo papel de Biblioteca Escolar e de Biblioteca Pública.

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Background Primary bacterial endosymbionts of insects (p-endosymbionts) are thought to be undergoing the process of Muller's ratchet where they accrue slightly deleterious mutations due to genetic drift in small populations with negligible recombination rates. If this process were to go unchecked over time, theory predicts mutational meltdown and eventual extinction. Although genome degradation is common among p-endosymbionts, we do not observe widespread p-endosymbiont extinction, suggesting that Muller's ratchet may be slowed or even stopped over time. For example, selection may act to slow the effects of Muller's ratchet by removing slightly deleterious mutations before they go to fixation thereby causing a decrease in nucleotide substitutions rates in older p-endosymbiont lineages. Methodology/Principal Findings To determine whether selection is slowing the effects of Muller's ratchet, we determined the age of the Candidatus Riesia/sucking louse assemblage and analyzed the nucleotide substitution rates of several p-endosymbiont lineages that differ in the length of time that they have been associated with their insect hosts. We find that Riesia is the youngest p-endosymbiont known to date, and has been associated with its louse hosts for only 13–25 My. Further, it is the fastest evolving p-endosymbiont with substitution rates of 19–34% per 50 My. When comparing Riesia to other insect p-endosymbionts, we find that nucleotide substitution rates decrease dramatically as the age of endosymbiosis increases. Conclusions/Significance A decrease in nucleotide substitution rates over time suggests that selection may be limiting the effects of Muller's ratchet by removing individuals with the highest mutational loads and decreasing the rate at which new mutations become fixed. This countering effect of selection could slow the overall rate of endosymbiont extinction.

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A recently emerging bleeding canker disease, caused by Pseudomonas syringae pathovar aesculi (Pae), is threatening European horse chestnut in northwest Europe. Very little is known about the origin and biology of this new disease. We used the nucleotide sequences of seven commonly used marker genes to investigate the phylogeny of three strains isolated recently from bleeding stem cankers on European horse chestnut in Britain (E-Pae). On the basis of these sequences alone, the E-Pae strains were identical to the Pae type-strain (I-Pae), isolated from leaf spots on Indian horse chestnut in India in 1969. The phylogenetic analyses also showed that Pae belongs to a distinct clade of P. syringae pathovars adapted to woody hosts. We generated genome-wide Illumina sequence data from the three E-Pae strains and one strain of I-Pae. Comparative genomic analyses revealed pathovar-specific genomic regions in Pae potentially implicated in virulence on a tree host, including genes for the catabolism of plant-derived aromatic compounds and enterobactin synthesis. Several gene clusters displayed intra-pathovar variation, including those encoding type IV secretion, a novel fatty acid biosynthesis pathway and a sucrose uptake pathway. Rates of single nucleotide polymorphisms in the four Pae genomes indicate that the three E-Pae strains diverged from each other much more recently than they diverged from I-Pae. The very low genetic diversity among the three geographically distinct E-Pae strains suggests that they originate from a single, recent introduction into Britain, thus highlighting the serious environmental risks posed by the spread of an exotic plant pathogenic bacterium to a new geographic location. The genomic regions in Pae that are absent from other P. syringae pathovars that infect herbaceous hosts may represent candidate genetic adaptations to infection of the woody parts of the tree.

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Pre-term birth is the leading cause of perinatal and neonatal mortality, 40% of which are attributed to the pre-term premature rupture of amnion. Rupture of amnion is thought to be associated with a corresponding decrease in the extracellular collagen content and/or increase in collagenase activity. However, there is very little information concerning the detailed organisation of fibrillar collagen in amnion and how this might influence rupture. Here we identify a loss of lattice like arrangement in collagen organisation from areas near to the rupture site, and present a 9% increase in fibril spacing and a 50% decrease in fibrillar organisation using quantitative measurements gained by transmission electron microscopy and the novel application of synchrotron X-ray diffraction. These data provide an accurate insight into the biomechanical process of amnion rupture and highlight X-ray diffraction as a new and powerful tool in our understanding of this process.

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Background: Serine proteases are major components of viper venom and target various stages of the blood coagulation system in victims and prey. A better understanding of the diversity of serine proteases and other enzymes present in snake venom will help to understand how the complexity of snake venom has evolved and will aid the development of novel therapeutics for treating snake bites. Methodology and Principal Findings: Four serine protease-encoding genes from the venom gland transcriptome of Bitis gabonica rhinoceros were amplified and sequenced. Mass spectrometry suggests the four enzymes corresponding to these genes are present in the venom of B. g. rhinoceros. Two of the enzymes, rhinocerases 2 and 3 have substitutions to two of the serine protease catalytic triad residues and are thus unlikely to be catalytically active, though they may have evolved other toxic functions. The other two enzymes, rhinocerases 4 and 5, have classical serine protease catalytic triad residues and thus are likely to be catalytically active, however they have glycine rather than the more typical aspartic acid at the base of the primary specificity pocket (position 189). Based on a detailed analysis of these sequences we suggest that alternative splicing together with individual amino acid mutations may have been involved in their evolution. Changes within amino acid segments which were previously proposed to undergo accelerated change in venom serine proteases have also been observed. Conclusions and Significance: Our study provides further insight into the diversity of serine protease isoforms present within snake venom and discusses their possible functions and how they may have evolved. These multiple serine protease isoforms with different substrate specificities may enhance the envenomation effects and help the snake to adapt to new habitats and diets. Our findings have potential for helping the future development of improved therapeutics for snake bites.

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Parasitic mites associated with spiders are spreading world-wide through the trade in tarantulas and other pet species. Ljunghia pulleinei Womersley, a mesostigmatic laelapid mite originally found in association with the mygalomorph spider Selenocosmia stirlingi Hogg (Theraphosidae) in Australia, is redescribed and illustrated on the basis of specimens from the African theraphosid spider Pterinochilus chordatus (Gersta¨cker) kept in captivity in the British Isles (Wales). The mite is known from older original descriptions of Womersley in 1956; the subsequent redescription of Domrow in 1975 seems to be questionable in conspecificity of treated specimens with the type material. Some inconsistencies in both descriptions are recognised here as intraspecific variability of the studied specimens. The genus Arachnyssus Ma, with species A. guangxiensis (type) and A. huwenae, is not considered to be a valid genus, and is included in synonymy with Ljunghia Oudemans. A new key to world species of the genus Ljunghia is provided.

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The goal of this research was to investigate the changes in neural processing in mild cognitive impairment. We measured phase synchrony, amplitudes, and event-related potentials in veridical and false memory to determine whether these differed in participants with mild cognitive impairment compared with typical, age-matched controls. Empirical mode decomposition phase locking analysis was used to assess synchrony, which is the first time this analysis technique has been applied in a complex cognitive task such as memory processing. The technique allowed assessment of changes in frontal and parietal cortex connectivity over time during a memory task, without a priori selection of frequency ranges, which has been shown previously to influence synchrony detection. Phase synchrony differed significantly in its timing and degree between participant groups in the theta and alpha frequency ranges. Timing differences suggested greater dependence on gist memory in the presence of mild cognitive impairment. The group with mild cognitive impairment had significantly more frontal theta phase locking than the controls in the absence of a significant behavioural difference in the task, providing new evidence for compensatory processing in the former group. Both groups showed greater frontal phase locking during false than true memory, suggesting increased searching when no actual memory trace was found. Significant inter-group differences in frontal alpha phase locking provided support for a role for lower and upper alpha oscillations in memory processing. Finally, fronto-parietal interaction was significantly reduced in the group with mild cognitive impairment, supporting the notion that mild cognitive impairment could represent an early stage in Alzheimer’s disease, which has been described as a ‘disconnection syndrome’.

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BACKGROUND: Obesity is rising at an alarming rate globally. Different fermentable carbohydrates have been shown to reduce obesity. The aim of the present study was to investigate if two different fermentable carbohydrates (inulin and b-glucan) exert similar effects on body composition and central appetite regulation in high fat fed mice. METHODOLOGY/PRINCIPAL FINDINGS: Thirty six C57BL/6 male mice were randomized and maintained for 8 weeks on a high fat diet containing 0% (w/w) fermentable carbohydrate, 10% (w/w) inulin or 10% (w/w) b-glucan individually. Fecal and cecal microbial changes were measured using fluorescent in situ hybridization, fecal metabolic profiling was obtained by proton nuclear magnetic resonance (1H NMR), colonic short chain fatty acids were measured by gas chromatography, body composition and hypothalamic neuronal activation were measured using magnetic resonance imaging (MRI) and manganese enhanced MRI (MEMRI), respectively, PYY (peptide YY) concentration was determined by radioimmunoassay, adipocyte cell size and number were also measured. Both inulin and b-glucan fed groups revealed significantly lower cumulative body weight gain compared with high fat controls. Energy intake was significantly lower in b-glucan than inulin fed mice, with the latter having the greatest effect on total adipose tissue content. Both groups also showed an increase in the numbers of Bifidobacterium and Lactobacillus-Enterococcus in cecal contents as well as feces. b- glucan appeared to have marked effects on suppressing MEMRI associated neuronal signals in the arcuate nucleus, ventromedial hypothalamus, paraventricular nucleus, periventricular nucleus and the nucleus of the tractus solitarius, suggesting a satiated state. CONCLUSIONS/SIGNIFICANCE: Although both fermentable carbohydrates are protective against increased body weight gain, the lower body fat content induced by inulin may be metabolically advantageous. b-glucan appears to suppress neuronal activity in the hypothalamic appetite centers. Differential effects of fermentable carbohydrates open new possibilities for nutritionally targeting appetite regulation and body composition.

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In addition to the expression of recombinant proteins, baculoviruses have been developed as a platform for the display of complex eukaryotic proteins on the surface of virus particles or infected insect cells. Surface display has been used extensively for antigen presentation and targeted gene delivery but is also a candidate for the display of protein libraries for molecular screening. However, although baculovirus gene libraries can be efficiently expressed and displayed on the surface of insect cells, target gene selection is inefficient probably due to super-infection which gives rise to cells expressing more than one protein. In this report baculovirus superinfection of Sf9 cells has been investigated by the use of two recombinant multiple nucleopolyhedrovirus carrying green or red fluorescent proteins under the control of both early and late promoters (vAcBacGFP and vAcBacDsRed). The reporter gene expression was detected 8 hours after the infection of vAcBacGFP and cells in early and late phases of infection could be distinguished by the fluorescence intensity of the expressed protein. Simultaneous infection with vAcBacGFP and vAcBacDsRed viruses each at 0.5 MOI resulted in 80% of infected cells coexpressing the two fluorescent proteins at 48 hours post infection (hpi), and subsequent infection with the two viruses resulted in similar co-infection rate. Most Sf9 cells were re-infectable within the first several hours post infection, but the reinfection rate then decreased to a very low level by 16 hpi. Our data demonstrate that Sf9 cells were easily super-infectable during baculovirus infection, and super-infection could occur simultaneously at the time of the primary infection or subsequently during secondary infection by progeny viruses. The efficiency of super-infection may explain the difficulties of baculovirus display library screening but would benefit the production of complex proteins requiring co-expression of multiple polypeptides.

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By modelling the average activity of large neuronal populations, continuum mean field models (MFMs) have become an increasingly important theoretical tool for understanding the emergent activity of cortical tissue. In order to be computationally tractable, long-range propagation of activity in MFMs is often approximated with partial differential equations (PDEs). However, PDE approximations in current use correspond to underlying axonal velocity distributions incompatible with experimental measurements. In order to rectify this deficiency, we here introduce novel propagation PDEs that give rise to smooth unimodal distributions of axonal conduction velocities. We also argue that velocities estimated from fibre diameters in slice and from latency measurements, respectively, relate quite differently to such distributions, a significant point for any phenomenological description. Our PDEs are then successfully fit to fibre diameter data from human corpus callosum and rat subcortical white matter. This allows for the first time to simulate long-range conduction in the mammalian brain with realistic, convenient PDEs. Furthermore, the obtained results suggest that the propagation of activity in rat and human differs significantly beyond mere scaling. The dynamical consequences of our new formulation are investigated in the context of a well known neural field model. On the basis of Turing instability analyses, we conclude that pattern formation is more easily initiated using our more realistic propagator. By increasing characteristic conduction velocities, a smooth transition can occur from self-sustaining bulk oscillations to travelling waves of various wavelengths, which may influence axonal growth during development. Our analytic results are also corroborated numerically using simulations on a large spatial grid. Thus we provide here a comprehensive analysis of empirically constrained activity propagation in the context of MFMs, which will allow more realistic studies of mammalian brain activity in the future.

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This thesis aims to investigate the development and functions of public libraries in Rome and the Roman world. After a preface with maps of libraries in Rome, Section I discusses the precursors for public library provision in the private book collections of Republican Rome, and their transfer into the public domain with the first public libraries of Asinius Pollio and Augustus. Section II contains three 'case studies' of public libraries' different roles. The Augustan library programme is used in Ch.II.l to examine the role of imperial public libraries in literary life and the connections between Rome's libraries and those of Alexandria. Chapter II.2 concentrates on the libraries of Trajan's Forum to explore the intersection of imperial public libraries and monumental public architecture. This chapter responds to an important recent article by arguing for the continued identification of the Forum's libraries with twin brick buildings at its northern end, and suggests a series of correspondences between these libraries and its other monumental components. The conclusions of this chapter are important when considering the public libraries of the wider empire, several of which seem to have been inspired by the Trajanic libraries. Chapter II.3 considers imperial public libraries and leisure by looking at the evidence for libraries within bath-house complexes, concluding that their presence there is consistent with the archaeological and epigraphic evidence and fits in well with what we know of the intellectual and cultural life of these structures. Section III examines various aspects of the practical function of Roman public libraries: their contents (books and archives), division into Latin and Greek sections, provisions for shelving and cataloguing, staff, usership, architectural form, decoration, and housing of works of art. The picture that emerges is of carefully designed and functional buildings intended to sustain public, monumental, and practical functions. Section IV uses a variety of texts to examine the way in which libraries were viewed and used. Ch. IV. 1 discusses the evidence for use of libraries by scholars and authors such as Gellius, Galen, Josephus, and Apuleius. Ch. IV.2 examines parallels between library collections and compendious encyclopaedic elements within Roman literature and considers how library collections came to be canon-forming institutions and vehicles for the expression of imperial approval or disapproval towards authors. The channels through which this imperial influence flowed are investigated in Ch. IV.3, which looks at the directors and staff of the public libraries of Rome. The final section (V) of the thesis concerns public libraries outside the city of Rome. Provincial libraries provide a useful case study in 'Romanisation': they reveal a range of influences and are shown to embody local, personal, and metropolitan imperial identities. There follows a brief conclusion, and a bibliography. There are also five appendices of numismatic and epigraphic material discussed in the text. This material has not been adequately or completely gathered elsewhere and is intended to assist the reader; where appropriate it includes illustrations, transcriptions, and translations.

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Ascaris suum is one of the most prevalent nematode parasites in pigs and causes significant economic losses, and also serves as a good model for A. lumbricoides, the large roundworm of humans that is ubiquitous in developing countries and causes malnutrition, stunted growth and compromises immunity to other pathogens. New treatment options for Ascaris infections are urgently needed, to reduce reliance on the limited number of synthetic anthelmintic drugs. In areas where Ascaris infections are common, ethno-pharmacological practices such as treatment with natural plant extracts are still widely employed. However, scientific validation of these practices and identification of the active compounds are lacking, although observed effects are often ascribed to plant secondary metabolites such as tannins. Here, we extracted, purified and characterised a wide range of condensed tannins from diverse plant sources and investigated anthelmintic effects against A. suum in vitro. We show that condensed tannins can have potent, direct anthelmintic effects against A. suum, as evidenced by reduced migratory ability of newly hatched third-stage larvae and reduced motility and survival of fourth-stage larvae recovered from pigs. Transmission electron microscopy showed that CT caused significant damage to the cuticle and digestive tissues of the larvae. Furthermore, we provide evidence that the strength of the anthelmintic effect is related to the polymer size of the tannin molecule. Moreover, the identity of the monomeric structural units of tannin polymers may also have an influence as gallocatechin and epigallocatechin monomers exerted significant anthelmintic activity whereas catechin and epicatechin monomers did not. Therefore, our results clearly document direct anthelmintic effects of condensed tannins against Ascaris and encourage further in vivo investigation to determine optimal strategies for the use of these plant compounds for the prevention and/or treatment of ascariosis.

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Salmonella enterica serovars Derby and Mbandaka are isolated from different groups of livestock species in the UK. S. Derby is predominantly isolated from pigs and turkeys and S. Mbandaka is predominantly isolated from cattle and chickens. Alignment of the genome sequences of two isolates of each serovar led to the discovery of a new putative Salmonella pathogenicity island, SPI-23, in the chromosome sequence of S. Derby isolates. SPI-23 is 37 kb in length and contains 42 ORFs, ten of which are putative type III effector proteins. In this study we use porcine jejunum derived cell line IPEC-J2 and in vitro organ culture of porcine jejunum and colon, to characterise the association and invasion rates of S. Derby and S. Mbandaka, and tissue tropism of S. Derby respectively. We show that S. Derby invades and associates to an IPEC-J2 monolayer in significantly greater numbers than S. Mbandaka, and that S. Derby preferentially attaches to porcine jejunum over colon explants. We also show that nine genes across SPI-23 are up-regulated to a greater degree in the jejunum compared to the colon explants. Furthermore, we constructed a mutant of the highly up-regulated, pilV-like gene, potR, and find that it produces an excess of surface pili compared to the parent strain which form a strong agglutinating phenotype interfering with association and invasion of IPEC-J2 monolayers. We suggest that potR may play a role in tissue tropism.