Carbapenem-resistant Acinetobacter baumannii is the top-ranked pathogen in the World Health Organization priority list of antibiotic-resistant bacteria. It emerged as a global pathogen due to the successful expansion of a few epidemic lineages, or international clones (ICs), producing acquired class D carbapenemases (OXA-type). During the past decade, however, reports regarding IC-I isolates in Latin America are scarce and are non-existent for IC-II and IC-III isolates. This study evaluates the molecular mechanisms of carbapenem resistance and the epidemiology of 80 non-duplicate clinical samples of A. baumannii collected from February 2014 through April 2016 at two tertiary care hospitals in Lima. Almost all isolates were carbapenem-resistant (97.5%), and susceptibility only remained high for colistin (95%). Pulsed-field gel electrophoresis showed two main clusters spread between both hospitals: cluster D containing 51 isolates (63.8%) associated with sequence type 2 (ST2) and carrying OXA-72, and cluster F containing 13 isolates (16.3%) associated with ST79 and also carrying OXA-72. ST2 and ST79 were endemic in at least one of the hospitals. ST1 and ST3 OXA-23-producing isolates were also identified. They accounted for sporadic hospital isolates. Interestingly, two isolates carried the novel OXA-253 variant of OXA-143 together with an upstream novel insertion sequence (ISAba47). While the predominant A. baumannii lineages in Latin America are linked to ST79, ST25, ST15, and ST1 producing OXA-23 enzymes, we report the emergence of highly resistant ST2 (IC-II) isolates in Peru producing OXA-72 and the first identification of ST3 isolates (IC-III) in Latin America, both considered a serious threat to public health worldwide. / This study was supported by Cienciactiva of CONCYTEC, contract no. 164-2016-FONDECYT; Planes Nacionales de I+D+i 2008-2011/2013-2016, Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI RD12/0015/0013 and REIPI RD16/0016/ 0010); the 2017 call for Strategic Action on Health (PI17/01932), co-financed by European Development Regional Fund “A way to achieve Europe” and operative program Intelligent Growth 2014-2020; and grant 2014 SGR 0653 from the Departament d’Universitats, Recerca i Societat de la Informació, of the Generalitat de Catalunya. I.R. was supported by the Department of Health, Generalitat de Catalunya, grant SLT002/16/00349. Part of these data have been presented as a poster communication at the 18th International Congress on Infectious Diseases, 3–4 March, 2018, Buenos Aires, Argentina, and at the XXVIII-European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), Madrid (Spain), 21–24 April, 2018 / Revisión por pares

This study is concerned with non-heterosexual women, who are commonly known as lalas in China. The conditions for non-heterosexuals in China have been improving since the beginning of the reform period. But despite that the life of lalas is still full of difficulties because how the government, family and market operate is under heavy influence of heterosexism. Compared with other non-heterosexuals such as gay men, the difficulties faced by lalas receive much less attention not only in society but also in academic communities. To address this important but understudied area, this research focuses on the social exclusion faced by lalas and the anti-exclusion strategies they prefer to use. No study has been done on these issues in a systematic way before. The findings of the study serve to enhance our understanding of lalas and develop effective anti-exclusion strategies preferred by them. Moreover, the discussion of the findings of this study is intended to contribute to knowledge advancement especially in identifying the grey areas of the studies of the welfare mix approaches and the adult worker models. Against this background, this research focuses on two main research questions (What are the patterns of social exclusion faced by lalas in China? What are the strategies preferred by lalas in China?) and two supplementary research questions (What are the implications of the study of social exclusion experience of lalas in China on the study of the welfare mix approaches? What are the implications of the study of the social exclusion experience of lalas in China on the study of adult worker models?) Thanks to the 20 lalas informants, this research project obtains their important views on social exclusion through in-depth interviews. Despite the unfavorable conditions for non-heterosexuals to share views about their life in China, the lalas informants provide valuable information about social exclusion (or inclusion) issues they face in their daily life in the past, present and future (such as discriminations in school, work and difficulties to get along with family members) and the ways they try to deal with these issues (such as making plans on contract marriage, migration and cohabitation). This information, supplemented by those obtained from reviews of formal and informal document, and participant observations, provides insights into the examination of the anti-exclusion strategies (such as the RED, SID and social detachment) preferred by them, and the discussion of the importance of developing welfare mix approaches and the adult worker models based on non-heterosexism Furthermore, the findings show the commonalities and differences between lalas in their response to social exclusion. It is important to note that there is a gap between the anti-exclusion strategies many lalas prefer and what they could actually use. It is equally important to note that some lalas could effectively deal with most of the life difficulties and become an invulnerable at least in some period of life. This discovery is useful both in gaining recognition of the unique life experience of each lala, and exploring the possibilities for lalas to tackle their shared problems in joint efforts.

Abstract The mast cells are an integral part of the human immune system. They are important modulators of inflammatory and physiological processes. Mast cells exert their functions through degranulation and release of inflammatory mediators, such as histamine, proteases and cytokines. There are two main pathways leading to the mast cell activation, the immunoglobulin-dependent and the immunoglobulin-independent pathway. The latter pathway can be triggered by several non-immunological stimuli, and two novel receptors responsible for the activation have been identified, the MAS-related G protein-coupled receptor X1 (MRGPRX1) and X2. The MRGPRX1 and MRGPRX2 have two established functions: i) they trigger the degranulation of mast cells and ii) they are involved in pain perception and itch on a specific subset of sensory neurons. These receptors are not expressed in all of the populations of mast cells, only in the tryptase and chymase containing mast cells, contributing to the mast cell heterogeneity. Unlike most G protein-coupled receptors, the MRGPRX1 and MRGPRX2 are quite non-selective, binding an ever growing list of different ligands. Their ligands include endogenous neuropeptides, host defense peptides and protein fragments, as well as synthetic compounds such as different antibiotics. Their endogenous ligands could be a triggering signal in some mast cell-related diseases by degranulating mast cells and thereby inducing inflammation. Due to the non-selectivity of MRGPRX1 and MRGPRX2, they probably still have many hitherto unknown ligands. The aim of this study was to isolate novel endogenous ligands for the MRGPRX1 and MRGPRX2 from human tissues with the “reverse pharmacology approach” and to determine their potential to degranulate mast cells. The starting materials for the isolation, human platelets and plasma, contained MRGPRX1 and MRGPRX2 activating compounds. From the human plasma, three fragments of albumin able to activate the MRGPRX2 were isolated and sequenced. These fragments were dose-dependently activating the MRGPRX2 and degranulating mast cells. Two MRGPRX1 activating hemoglobin β-chain fragments were isolated from human platelets. These fragments were dose-dependently activating the MRGPRX1, but had no effect on mast cell degranulation. / Tiivistelmä Syöttösolut on tärkeä osa ihmisen immuunijärjestelmää. Ne ovat tärkeitä tulehdus- ja fysiologistenprosessien säätelijöitä. Syöttösolujen vaikutus välittyy degranulaation ja siinä vapautuvien tulehdusvälittäjäaineiden kautta. Vapautuviin aineisiin lukeutuu esim. histamiini ja lukuisia sytokiinejä, sekä proteaaseja. Syöttösolujen aktivaatio voi tapahtua immunoglobuliineista riippuvaa tai immunoglobuliineista riippumatonta reittiä pitkin. Monet ei-immunologiset tekijät voivat laukaista jälkimmäisen reitin ja kaksi uutta tähän vaikuttavaa G-proteiinikytkentäistä reseptoria on löydetty, MAS-related G protein-coupled receptor X1 (MRGPRX1) ja X2. MRGPRX1:llä ja MRGPRX2:lla on kaksi tunnettua tehtävää: i) ne laukaisevat syöttösolujen degranulaation ja ii) ne osallistuvat kivun ja kutinan aistimiseen tietyissä tuntohermoissa. Näitä reseptoreita ei ilmennetä kaikissa syöttösoluissa, vaan ainoastaa tryptaasia ja kymaasia sisältävissä syöttösoluissa, ja täten osaltaan selittävät syöttösolujen monimuotoisuutta. Useimmista G-proteiinikytkentäisistä reseptoreista poiketen MRGPRX1 ja MRGPRX2 ovat laajakirjoisia, sitoen monia erilaisia ligandeja. Ligandeihin kuuluu endogeenisia neuropeptidejä, antimikrobiaalisia peptidejä ja proteiinin fragmentteja, sekä synteettisiä yhdisteitä kuten erilaisia antibiootteja. Reseptoreiden endogeeniset ligandit voivat toimia laukaisijana jossain syöttösoluihin liittyvissä sairauksissa, degranuloidessaan syöttösoluja ja aiheuttaen paikallisen tulehdustilan. Reseptoreiden laajakirjoisuudesta johtuen niillä on oletettavasti monia vielä tuntemattomia ligandeja. Tämän tutkimuksen tarkoitus oli eristää uusia endogeenisiä ligandeja MRGPRX1:lle ja MRGPRX2:lle ihmisen kudoksista ”kääteisfarmakologista lähestymistapaa” hyödyntäen ja selvittää ligandien kyky syöttösolujen degranulaatioon. Lähtömateriaalina käytetyt ihmisen verihiutaleet ja plasma sisälsivät MRGPRX1:ta ja MRGPRX2:ta aktivoivia yhdisteitä. Plasmasta eristettiin ja sekvensoitiin kolme albumiinin fragmenttia, jotka aktivoivat MRGPRX2:ta. Nämä fragmentit aktivoivat MRGPRX2:ta ja degranuloivat syöttösoluja annosriippuvaisesti. Kaksi MRGPRX1:tä aktivoivaa hemoglobiinin β-ketjun fragmenttia eristettiin ihmisen verihiutaleista. Nämä fragmentit tunnistettiin hemorfiineiksi ja ne aktivoivat MRGPRX1:tä annosriippuvaisesti, mutta eivät vaikuttaneet syöttösolujen degranulaatioon.

No description available.

Master of Science / Department of Electrical and Computer Engineering / William B. Kuhn / Crosstalk and electromagnetic interference (EMI) are constant problems in the design of RF circuits. There have been several studies to analyze and improve isolation of transmission lines, but the focus has been mainly on digital circuits or the isolation goals have been on the order of 40-60 dB. When the isolation goals are much more stringent, such as 80-100 dB, much of a designer’s time is still spent ensuring that a circuit meets isolation and EMI constraints. This typically involves the use of extensive metal shielding over a circuit board. This thesis presents results from an isolation and EMI study to provide a simple reference that can be applied to typical substrates, provided proper scaling is used between substrates. The results in this thesis are reported from DC to 30 GHz using a low cost 4-layer FR4 process. The changes in isolation between various transmission lines types are investigated while varying line separation and length. It is shown that isolation between ground-backed coplanar waveguide (GBCPW) and stripline traces can reach 100dB through L-band and 60dB through Ku-band for 1.3in traces separated by 150mils. Due to the heavy usage of filters in RF design, the isolation between edge-coupled bandpass filters is also studied. It is seen that isolation levels of 100dB through L-band by enclosing the filters within stripline technology is possible, provided that signal launches and layer transitions are carefully designed. Within the passband of the 20 GHz filter tested, the isolation is less but is still significantly improved by use of enclosed stripline. Lastly, a preliminary assessment of EMI is presented which focuses on radiation levels as well as variables that can degrade isolation performance. The data illustrated in this thesis can provide guidance in the early stages of RF circuit design to determine appropriate structures to meet given design requirements. It also helps to assess the degree to which additional metal shielding can be avoided in PC board systems that use multi-layer technologies.

A number of exoglycosidases have been prepared from bacterial and plant sources using established methods for the separation of enzymes, in conjunction with certain novel purification systems hitherto not described in the literature for these enzymes. The enzyme, beta-galactosidase from E. coli has been prepared using previously described methods of phase separation and ion-exchange chromatography. As a final step in this purification, the use of a new hydroxyl-rich chromatographic support for the isolation of high-grade enzyme suitable for use in enzyme immunoassays was investigated. Methods have also been studied for the recovery of alpha-mannosidase as a by-product of the procedure used for the extraction of urease from jack bean (Canavalia ensiformis). The inclusion of a novel step involving the use of hydrophobic-interaction chromatography on Phenyl-Sepharose led to excellent recoveries of enzyme suitable for commercial use. Studies on a second glycosidase, beta-N-acetylhexosaminidase, from the same source (jack bean) paved the way for an adaptation of existing purification methods to provide increased yields and an improved quality of enzyme. Since the research unit in which this work was performed is associated with commercial organizations responsible for the preparation and marketing of biologically active products, it is important that the methods of purification described in this thesis are compatible with the requirements for largescale purification.

Previous work on the binding of resting platelets to the basement membrane glycoprotein, laminin, has identified the Ic/IIa integrin c01aplex (CD49f/CD29), also known as VLA-6, as the receptor. There exists however, another protein with a molecular weight of 67kDa, that mediates this function on other cells. It is abundantly expressed on the membranes of breast cancer cells, where it plays a key role in both the localisation at, and penetration of vascular beds, by metastases. The objectives of this study were: * The development of a micro-titre assay similar to those used in previous studies, standardised and calibrated to characterize the adhesion of unstimulated normal human platelets to laminin-coated surfaces. * To determine the effect on adhesion of platelet activation, enzymatic surface-glycoprotein removal, antibodies to specific receptors and interaction with other adhesive proteins known to bind to platelet membranes. * To establish the in vivo relevance of the experimental findings, by the assay of adhesion of glycoprotein IIb/IIIa-deficient platelets of two patients with Glanzmann's Thrombasthenia. These studies serve d to distinguish specific binding sites for laminin from the known surface receptors of platelets. The methodology used to isolate laminin receptors from the membranes of breast carcinoma cells was then applied to platelet concentrates. Membranes were obtained by centrifuging the ultrasonic lysate of a unit of platelets. These were solubilized and passed over a laminin-Sepharose column. The bound components were eluted and identified by means of SDS-gel electrophoresis, after which a concentrate was tested for laminin binding by means of dot-blot methodology. The principle contribution of this work is the finding of a 67kDa receptor for laminin on the surface membranes of platelets. The combination of the various approaches applied to characterise the adhesion of platelets to laminin, show that this is a specific, Mg²⁺-dependent process, inhibited by Ca²⁺ and not enhanced by platelet activation. Adhesion was decreased by proteolysis with trypsin and chymotrypsin, showing that the adhesion is mediated by a surface glycoprotein. Proteolysis with the Serratia marcescens metalloprotease, which cleaves off glycoprotein lb, did not affect adhesion, proving that this well-known receptor for platelet adhesion is not involved in the adhesion. The receptors GPIV and glycocalicin were also excluded, as the presence of antibodies to these receptors had no effect. Prior incubation with fibrinogen or von Willebrand factor, which binds to specific receptors on the platelet membrane, inhibited adhesion, most likely due to spatial interference with the receptor site for laminin. The presence of the tetrapeptide recognised by the membrane receptors for many adhesive proteins, RGDS, at concentrations of up to 1mM, had no effect. The platelets of the two subjects with Glanzmann's Thrombasthenia adhered normally, definitively ruling out the involvement of GPIIb/IIIa, which is absent from these platelets. The isolation process recovered a membrane component from the laminin-Sepharose column with an elution pattern identical to that for the well characterised 67kDa receptor for laminin on the surface of breast carcinoma cells. They have the same molecular weights in both the reduced (67kDa) and non-reduced (53kDa) states. Blot identification demonstrated laminin binding by the eluate. In the last part of the work, collaborative studies using more sophisticated methodology have confirmed that platelet receptors for laminin play a role in their adhesion to living tissue. Anti-laminin Fab antibodies significantly decreased the adhesion when whole blood was perfused over isolated rabbit aortic segments. That these receptors are identical to the 67kDa receptor of breast carcinoma cells was shown by the specific, high affinity binding of antibodies directed at the carcinoma receptors to the surface of platelets when examined by flow cytometry. In addition, they inhibit platelet adhesion by 50-60% in the micro-titre assay. It is proposed that both the VLA-6 and the 67kDa receptors are required for platelet adhesion to laminin, possibly as a two-stage process, similar to the systems for adhesion to von Willebrand factor, where binding is initially to GPIb, followed by binding to GPIIb/IIIa. The possible relevance of this receptor in the pathophysiology of the metastatic process is discussed.

The research for this thesis was done on a comparative, documentary level, rather than on an empirical one. The issue as to whether or not dagga is physiologically harmful will probably be finally settled by medical and pharmacological study. This thesis does not go into these aspects; instead it attempts to set the development of dagga smoking as a social problem in historical perspective. The research has been done from secondary sources. These include the original works of some of the theorists on deviant behaviour, the reports of government committees of inquiry, as well as commentary on drug abuse in various academic and professional journals and in more popular publications. Special mention must be made of the use of newspaper reports as sources of reference in this study. In evaluating the rapidly- changing problem of drug abuse and social attitudes towards this phenomenon, it is often Press reports that carry the most up-to-date information on current research and changes in social policy. For this reason references to professional journals and other academic sources have in some instances been supplemented by relevant newspaper articles and reports. The validity of this approach is especially evident when dealing with South Africa. For example, the dimensions of the drug problem in the Republic were first revealed in a series of reports in a Johannesburg newspaper, the Rand Daily Mail, which brought home to the public the extent to which the problem of dagga abuse involved the youth of South Africa. These reports contributed directly to the appointment in 1970 of a Committee of Inquiry to investigate the abuse of drugs in this country.

The aim of this project was to identify growth phase-specific heat shock proteins of Mycobacterium smegmatis LR222. A growth curve was constructed using the ATP assay. This method was shown by B. A. Ntolosi to be the most accurate indicator of when the organism entered the various phases of growth. It was possible to determine that M. smegmatis LR222 entered the exponential phase of growth after a short lag phase of 4 to 8 hours and persisted in this phase for 20 to 22 hours. It then reached the stationary phase, which lasted for 40 to 46 hours. Protein heat shock assays were performed on growth phase-specific samples. This allowed the identification of a 43-46 kDa in molecular weight stationary phase protein on one-dimensional SOS-PAGE. The protein was induced in cells entering the stationary phase of growth and not by heat shock as it was induced under both the control and the heat shock temperatures. The protein was further characterised by two-dimensional gel electrophoresis, which demonstrated resolution into two, strongly age-associated, proteins. Subtractive RNA hybridisation was attempted in order to obtain a subtraction cDNA probe from a stationary phase RNA sample depleted of sequences common in both the exponential and the stationary phase samples. Ribosomal RNA was removed from the total RNA by the process of photobiotinilation. The mRNA was then used as a template to synthesise with reverse transcriptase single stranded cDNA. cDNA/mRNA denatured hybrids were hybridised to the exponential phase RNA sample. The new hybrids were "subtracted" by chemical cross-linking with DZQ and the unique cDNA used to produce by random primers a radioactively labelled probe. A M. smegmatis library was probed but unfortunately no signal was observed. Further adjustments and improvements to this technique are required before it can be used effectively.

Dans une première partie, nous étudions la cohérence dans les systèmes transactionnels, en nous concentrant sur le problème de réconcilier la scalabilité avec des garanties transactionnelles fortes. Nous identifions quatre propriétés critiques pour la scalabilité. Nous montrons qu’aucun des critères de cohérence forte existants n’assurent l’ensemble de ces propriétés. Nous définissons un nouveau critère, appelé Non-Monotonic Snapshot Isolation ou NMSI, qui est le premier à être compatible avec les quatre propriétés à la fois. Nous présentons aussi une mise en œuvre de NMSI, appelée Jessy, que nous comparons expérimentalement à plusieurs critères connus. Une autre contribution est un canevas permettant de comparer de façon non biaisée différents protocoles. Elle se base sur la constatation qu’une large classe de protocoles transactionnels distribués est basée sur une même structure, Deferred Update Replication(DUR). Les protocoles de cette classe ne diffèrent que par les comportements spécifiques d’un petit nombre de fonctions génériques. Nous présentons donc un canevas générique pour les protocoles DUR.La seconde partie de la thèse a pour sujet la cohérence dans les systèmes de stockage non transactionnels. C’est ainsi que nous décrivons Tuba, un stockage clef-valeur qui choisit dynamiquement ses répliques selon un objectif de niveau de cohérence fixé par l’application. Ce système reconfigure automatiquement son ensemble de répliques, tout en respectant les objectifs de cohérence fixés par l’application, afin de s’adapter aux changements dans la localisation des clients ou dans le débit des requête. / In the first part, we study consistency in a transactional systems, and focus on reconciling scalability with strong transactional guarantees. We identify four scalability properties, and show that none of the strong consistency criteria ensure all four. We define a new scalable consistency criterion called Non-Monotonic Snapshot Isolation (NMSI), while is the first that is compatible with all four properties. We also present a practical implementation of NMSI, called Jessy, which we compare experimentally against a number of well-known criteria. We also introduce a framework for performing fair comparison among different transactional protocols. Our insight is that a large family of distributed transactional protocols have a common structure, called Deferred Update Replication (DUR). Protocols of the DUR family differ only in behaviors of few generic functions. We present a generic DUR framework, called G-DUR. We implement and compare several transactional protocols using the G-DUR framework.In the second part, we focus on ensuring consistency in non-transactional data stores. We introduce Tuba, a replicated key-value store that dynamically selects replicas in order to maximize the utility delivered to read operations according to a desired consistency defined by the application. In addition, unlike current systems, it automatically reconfigures its set of replicas while respecting application-defined constraints so that it adapts to changes in clients’ locations or request rates. Compared with a system that is statically configured, our evaluation shows that Tuba increases the reads that return strongly consistent data by 63%.