Academic literature on the topic 'Side chain linked'

We reported an enhanced ACE2 peptidomimetic with high binding affinity (16 nM) to the SARS-CoV-2 spike RBD that potently inhibits SARS-CoV-2 pseudovirus in Huh7-hACE2 cells and neutralizes authentic SARS-CoV-2 in Caco2 cells.

The preparation of ether-linked porphyrin dimers and oligomers which are analogues of those present in the anticancer drugs hematoporphyrin derivative and Photofrin IIR is described. These materials are prepared from the appropriately substituted porphyrins containing a 1-hydroxyethyl or a vinyl side chain through an intermediate 1-bromoethyl derivative. Ether-linked porphyrin dimers with ethyl, formyl , hydroxymethyl and 1-alkoxyethyl side chains were prepared, together with trimers and tetramers containing ethyl side chains. Some of the spectroscopic and biological properties of these compounds are discussed.

The preparation is described of all of the likely dimer and trimer ether-linked components of the anticancer material known as hematoporphyrin derivative. The hydroxyethyl side chain of one porphyrin, related to hematoporphyrin, reacts readily with a bromoethyl system derived from the same, or similar, hematoporphyrin -derived porphyrin to form a diporphyrin ether. The coupling reaction can be controlled to occur in situ, allowing the preparation of a symmetrical ether-linked dimer , or separately to provide an asymmetrically substituted porphyrin dimer . The bromoethyl groups can be formed from either the hydroxyethyl groups or, more slowly, from a vinyl side chain by using hydrogen bromide in dichloromethane. Ether-linked porphyrin trimers can be prepared by reacting a dibromoethyl system with 2 equiv. of a hydroxyethyl -containing porphyrin or by further reaction of an initially formed dimer. Hydroxyethyl side chains in the dimers and trimers are best obtained by reduction of an acetyl group. Some spectral properties of the products are described.

New azobenzene derivatives with dihydropyrazole heterocycle have been prepared and characterized. According to thermal polarizing microscopy and differential scanning calorimetry studies, the compounds consisting of four linearly linked rings and a long alkoxy chain on the azobenzene side ( 3a-8 and 3a-14 ) displayed no liquid crystal properties. When the length of mesogenic unit increased to five rings, except for compound 5a-8 , all compounds from 5a-10 to 5a-16 containing a long chain of 10–16 carbon atoms on the side of ester group displayed liquid crystalline properties, and the mesogenic domain gradually narrowed with increase of the chain length. However, in the case of the molecule with long alkoxy chains on both sides, only 5c-16 with a long chain of 16 carbon atoms exhibited liquid crystal behaviour. In addition, these azo compounds underwent isomerization from E to Z under ultraviolet irradiation and then thermal back relaxation slowly in the dark, which can be recycled many times.

The vacuolar protease B of Saccharomyces cerevisiae is a subtilisin-like protease encoded by the PRB1 gene. Antibodies raised against a synthetic peptide and an Escherichia coli-derived PRB1 open reading frame (ORF) protein cross-react with authentic protease B from yeast. By using these antibodies, the posttranslational biosynthetic pathway of protease B has been elucidated. Preproprotease B is a 76-kD unglycosylated precursor that enters the endoplasmic reticulum (ER), where it receives one asparagine-linked (Asn-linked) and an undetermined number of non-Asn-linked carbohydrate side chains. The large glycosylated intermediate is proteolytically processed to a 39-kD form before exiting the ER. In the Golgi complex, the 39-kD form becomes 40 kD, due to elaboration of the Asn-linked side chain. The carboxyterminal end of the 40-kD proprotease B undergoes protease A-mediated processing to a 37-kD intermediate, which in turn is quickly processed to 31-kD mature protease B. The ultimate processing step removes a peptide containing the Asn-linked chain; mature PrB has only non-Asn-linked carbohydrate.

The aim of the project was to synthesise a novel small peptide containing an ether linkage between two side chains. Computer modelling had shown the structure was likely to form a stable p turn in solution and would therefore be a good candidate to study this class of protein secondary structure. To do this a differentially protected bis-amino acid containing the ether linkage was retrosynthesised to chiral pool synthons L-aspartic acid and L-methionine. Many attempts were then made to differentially protect and manipulate the respective acid and sulfide side chains into synthons that would participate in Williamson ether synthesis. Techniques explored included N-chlorosuccinimide hemithioacetal formation, sulfonium salt displacement, bismuth trichloride and silver salt induced etherifications. Using molecules made during this research we then worked towards making a similarly constrained peptide containing a homolanthionine bridge, a thioether analogue of the anti-tryptic reactive site loop of Bowman Birk Inhibitor, a proteinase inhibitor protein. Chapter 1 contains a review of peptides constrained through bridging of side chains and the effects that this has upon them. Chapters 2 and 3 outline the synthetic steps that were used in the process of synthesising an ether linked bis-amino acid. Subchapter 2.2 shows the synthesis of protected homoserine, a nucleophile for ether reactions. Subchapter 2.3 highlights the difficulty in making differentially protected electrophilic amino acids and coupling reactions between the two synthons. In chapter 3 the protected electrophilic homoserine is coupled with cysteine to make a homolanthionine bridge which is then integrated into a short peptide. Chapter 6 contains the experimental procedures for the reactions carried out and the spectral data for isolated compounds.

Doutoramento em Bioquímica
Os polissacarídeos são os componentes maioritários dos grãos de café verde e torrado e da bebida de café. Os mais abundantes são as galactomananas, seguindo-se as arabinogalactanas. Durante o processo de torra, as galactomananas e arabinogalactanas sofrem modificações estruturais, as quais estão longe de estar completamente elucidadas devido à sua diversidade e à complexidade estrutural dos compostos formados. Durante o processo de torra, as galactomananas e arabinogalactanas reagem com proteínas, ácidos clorogénicos e sacarose, originando compostos castanhos de alto peso molecular contendo nitrogénio, designados de melanoidinas. As melanoidinas do café apresentam diversas atividades biológicas e efeitos benéficos para a saúde. No entanto, a sua estrutura exata e os mecanismos envolvidos na sua formação permanecem desconhecidos, bem como a relação estrutura-atividade biológica. A utilização de sistemas modelo e a análise por espectrometria de massa permitem obter uma visão global e, simultaneamente, detalhada das modificações estruturais nos polissacarídeos do café promovidas pela torra, contribuindo para a elucidação das estruturas e mecanismos de formação das melanoidinas. Com base nesta tese, oligossacarídeos estruturalmente relacionados com a cadeia principal das galactomananas, (β1→4)-Dmanotriose (Man3), e as cadeias laterais das arabinogalactanas, (α1→5)-Larabinotriose (Ara3), isoladamente ou em misturas com ácido 5-Ocafeoilquínico (5-CQA), o ácido clorogénico mais abundante nos grãos de café verde, e péptidos compostos por tirosina e leucina, usados como modelos das proteínas, foram sujeitos a tratamento térmico a seco, mimetizando o processo de torra. A oxidação induzida por radicais hidroxilo (HO•) foi também estudada, uma vez que estes radicais parecem estar envolvidos na modificação dos polissacarídeos durante a torra. A identificação das modificações estruturais induzidas por tratamento térmico e oxidativo dos compostos modelo foi feita por estratégias analíticas baseadas principalmente em espectrometria de massa, mas também em cromatografia líquida. A cromatografia de gás foi usada na análise de açúcares neutros e ligações glicosídicas. Para validar as conclusões obtidas com os compostos modelo, foram também analisadas amostras de polissacarídeos do café obtidas a partir de resíduo de café e café instantâneo. Os resultados obtidos a partir dos oligossacarídeos modelo quando submetidos a tratamento térmico (seco), assim como à oxidação induzida por HO• (em solução), indicam a ocorrência de despolimerização, o que está de acordo com estudos anteriores que reportam a despolimerização das galactomananas e arabinogalactanas do café durante a torra. Foram ainda identificados outros compostos resultantes da quebra do anel de açúcares formados durante o tratamento térmico e oxidativo da Ara3. Por outro lado, o tratamento térmico a seco dos oligossacarídeos modelo (individualmente ou quando misturados) promoveu a formação de oligossacarídeos com um maior grau de polimerização, e também polissacarídeos com novos tipos de ligações glicosídicas, evidenciando a ocorrência de polimerização através reações de transglicosilação não enzimática induzidas por tratamento térmico a seco. As reações de transglicosilação induzidas por tratamento térmico a seco podem ocorrer entre resíduos de açúcares provenientes da mesma origem, mas também de origens diferentes com formação de estruturas híbridas, contendo arabinose e manose como observado nos casos dos compostos modelo usados. Os resultados obtidos a partir de amostras do resíduo de café e de café instantâneo sugerem a presença de polissacarídeos híbridos nestas amostras de café processado, corroborando a ocorrência de transglicosilação durante o processo de torra. Além disso, o estudo de misturas contendo diferentes proporções de cada oligossacarídeo modelo, mimetizando regiões do grão de café com composição distinta em polissacarídeos, sujeitos a diferentes períodos de tratamento térmico, permitiu inferir que diferentes estruturas híbridas e não híbridas podem ser formadas a partir das arabinogalactanas e galactomananas, dependendo da sua distribuição nas paredes celulares do grão e das condições de torra. Estes resultados podem explicar a heterogeneidade de estruturas de melanoidinas formadas durante a torra do café. Os resultados obtidos a partir de misturas modelo contendo um oligossacarídeo (Ara3 ou Man3) e 5-CQA sujeitas a tratamento térmico a seco, assim como de amostras provenientes do resíduo de café, mostraram a formação de compostos híbridos compostos por moléculas de CQA ligadas covalentemente a um número variável de resíduos de açúcar. Além disso, os resultados obtidos a partir da mistura contendo Man3 e 5-CQA mostraram que o CQA atua como catalisador das reações de transglicosilação. Por outro lado, nas misturas modelo contendo um péptido, mesmo contendo também 5-CQA e sujeitas ao mesmo tratamento, observou-se uma diminuição na extensão das reações transglicosilação. Este resultado pode explicar a baixa extensão das reações de transglicosilação não enzimáticas durante a torra nas regiões do grão de café mais ricas em proteínas, apesar dos polissacarídeos serem os componentes maioritários dos grãos de café. A diminuição das reações de transglicosilação na presença de péptidos/proteínas pode dever-se ao facto de os resíduos de açúcares redutores reagirem preferencialmente com os grupos amina de péptidos/proteínas por reação de Maillard, diminuindo o número de resíduos de açúcares redutores disponíveis para as reações de transglicosilação. Além dos compostos já descritos, uma diversidade de outros compostos foram formados a partir dos sistemas modelo, nomeadamente derivados de desidratação formados durante o tratamento térmico a seco. Em conclusão, a tipificação das modificações estruturais promovidas pela torra nos polissacarídeos do café abre o caminho para a compreensão dos mecanismos de formação das melanoidinas e da relação estrutura-atividade destes compostos.
Polysaccharides are the major components of green and roasted coffee beans, and coffee brew. The most abundant ones are galactomannans, followed by arabinogalactans. During the roasting process, galactomannans and arabinogalactans undergo structural modifications that are far to be completely elucidated due to their diversity and complexity of the compounds formed. During the roasting process, galactomannans and arabinogalactans react with proteins, chlorogenic acids, and sucrose, originating high molecular weight brown compounds containing nitrogen, known as melanoidins. Several biological activities and beneficial health effects have been attributed to coffee melanoidins. However, their exact structures and the mechanisms involved in their formation remain unknown, as well as the structure-biological activity relationship. The use of model systems and mass spectrometry analysis allow to obtain an overall view and, simultaneously, detailed, of the structural modifications in coffee polysaccharides promoted by roasting, contributing to the elucidation of the structures and formation mechanisms of melanoidins. Based on this thesis, oligosaccharides structurally related to the backbone of galactomannans, (β1→4)-D-mannotriose, and the side chains of arabinogalactans, (α1→5)-Larabinotriose, alone or in mixtures with 5-O-caffeoylquinic acid, the most abundant chlorogenic acid in green coffee beans, and dipeptides composed by tyrosine and leucine, used as models of proteins, were submitted to dry thermal treatments, mimicking the coffee roasting process. The oxidation induced by hydroxyl radicals (HO•) was also studied, since these radicals seem to be involved in the modification of the polysaccharides during roasting. The identification of the structural modifications induced by thermal and oxidative treatment of the model compounds was performed mostly by mass spectrometry-based analytical strategies, but also using liquid chromatography. Gas chromatography was used in the analysis of neutral sugars and glycosidic linkages. To validate the conclusions achieved with the model compounds, coffee polysaccharide samples obtained from spent coffee grounds and instant coffee were also analysed. The results obtained from the model oligosaccharides when submitted to thermal treatment (dry) or oxidation induced by HO• (in solution) indicate the occurrence of depolymerization, which is in line with previous studies reporting the depolymerization of coffee galactomannans and arabinogalactans during roasting. Compounds resulting from sugar ring cleavage were also formed during thermal treatment and oxidative treatment of Ara3. On the other hand, the dry thermal treatment of the model oligosaccharides (alone or when mixed) promoted the formation of oligosaccharides with a higher degree of polymerization, and also polysaccharides with new type of glycosidic linkages, evidencing the occurrence of polymerization via non-enzymatic transglycosylation reactions induced by dry thermal treatment. The transglycosylation reactions induced by dry thermal treatment can occur between sugar residues from the same origin, but also of different origins, with formation of hybrid structures, containing arabinose and mannose in the case of the model compounds used. The results obtained from spent coffee grounds and instant coffee samples suggest the presence of hybrid polysaccharides in these processed coffee samples, corroborating the occurrence of transglycosylation during the roasting process. Furthermore, the study of mixtures containing different proportions of each model oligosaccharide, mimicking coffee bean regions with distinct polysaccharide composition, subjected to different periods of thermal treatment, allowed to infer that different hybrid and non-hybrid structures may be formed from arabinogalactans and galactomannans, depending on their distribution in the bean cell walls and on roasting conditions. These results may explain the heterogeneity of melanoidins structures formed during coffee roasting. The results obtained from model mixtures containing an oligosaccharide (Ara3 or Man3) and 5-CQA and subjected to dry thermal treatment, as well as samples derived from spent coffee grounds, showed the formation of hybrid compounds composed by CQA molecules covalently linked to a variable number of sugar residues. Moreover, the results obtained from the mixture containing Man3 and 5-CQA showed that CQA acts as catalyst of transglycosylation reactions. On the other hand, in the model mixtures containing a peptide, even if containing 5-CQA and subjected to the same treatment, it was observed a decrease in the extent of transglycosylation reactions. This outcome can explain the low extent of non-enzymatic transglycosylation reactions during roasting in coffee bean regions enriched in proteins, although polysaccharides are the major components of the coffee beans. The decrease of transglycosylation reactions in the presence of peptides/proteins can be related with the preferential reactivity of reducing residues with the amino groups of peptides/proteins by Maillard reaction, decreasing the number of reducing residues available to be directly involved in the transglycosylation reactions. In addition to the compounds already described, a diversity of other compounds were formed from model systems, namely dehydrated derivatives formed during dry thermal treatment. In conclusion, the identification of the structural modifications in coffee polysaccharides promoted by roasting pave the way to the understanding of the mechanisms of formation of melanoidins and structure-activity relationship of these compounds.

This thesis discusses the design and production of peptides with side chain linkers that are intended to bind to the F3 domain of talin. The talin F3 domain was targeted as it is involved in the activation of integrin membrane proteins present in platelets. The over activation of these integrins can result in clotting within the blood vessels causing heart disease, however, current medication targeting integrin have negative side effects. The design and synthesis of short peptides based on the sequence of the β3 integrin tail that binds to the F3 domain of talin is presented. The binding affinity of peptides to the talin F3 domain was tested using NMR titrations to reveal the ideal location for the linker in the production of potential therapeutics which target integrin activation. Side chain linked peptides with high helical content have previously been shown to improve binding affinity. This drove investigation of side chain constrained peptides to increase their helical content, and thus, their binding affinity to talin F3 domain and cellular uptake. It is demonstrated that side chain linkers are effective in stabilising the helical structure of the short peptides. When incorporated in the β3 integrin sequence in specific locations, lactam linkers improved binding affinity of these peptides to the talin F3 domain. Additionally, all-hydrocarbon and triazole linkers enhanced the peptide’s cellular uptake when compared to the native peptide of this sequence. The position and type of side chain linkers were investigated. The result of which showed that the position of the linker had a significant impact on the binding affinity to talin. The lactam linker between residues in positions 725 and 729 created a peptide (7) with the highest binding affinity. The cell penetration of peptides with different linker types was tested using NIH 3T3 mouse cells, and HEK298 cells. A number of side chain linkers were tested with the triazole linker producing the most α-helical peptide, and the all-hydrocarbon linker producing peptides with the greatest cellular uptake.
Thesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 2018

This chapter, which yanks the reader from mid-twentieth-century Detroit to early twenty-first-century Guangdong Province, recounts the author's discovery that the labor question can have many different configurations, especially when some of the most important and characteristic enterprises of our day are the big-box retailers, whose employee rolls and annual revenues now far outrank those of the largest manufacturing companies. It appears that the essence of the twenty-first-century labor question no longer resides at the point of production in a struggle between workers and the owners of the factories in which they labor. Instead, the site of value production is found at every link along a set of global supply chains, in which the manufacturer and the warehouse operator, the ports and the shipping companies, as well as the retailers and their branded vendors jockey for power and profit. In this disaggregated system, legal ownership of the forces of production has been divorced from operational control, making accountability for labor conditions diffuse and knowledge of the actual producers far from transparent.

This chapter distills the book’s responses to two pivotal questions. If a sweeping, politically driven curtailment of fundamental liberties happens again, would the Korematsu majority’s highly deferential 1944 approach be expanded to new purposes to legitimize present-day transgressions of essential democratic liberties? Or would the courts undertake watchful care over those liberties by scrutinizing the government’s claim of necessity so that the talismanic incantation of national security itself does not enervate the judicial role? The chapter coalesces prior themes by first linking rubber-stamp judicial passivity to the deeply problematic shadow side of national security law; second by highlighting Korematsu and its coram nobis reopening as a cautionary tale; third, by repudiating Korematsu’s unconditional deference to the government’s claim of necessity; fourth by implicating judicial legitimacy in affirming Korematsu’s stated commitment to careful judicial scrutiny; and finally, by moving toward justice by breaking a key link in the chain of enduring injustice.

Protists are involved in many ecological roles in natural environments, including primary production, herbivory and carnivory, and parasitism. Microbial ecologists have been interested in these single-cell eukaryotes since Antonie van Leeuwenhoek saw them in his stool and scum from his teeth. This chapter focuses on the role of protozoa (purely heterotrophic protists) and other protists in grazing on other microbes. Heterotrophic nanoflagellates, 3–5 microns long, are the most important grazers of bacteria and small phytoplankton in aquatic environments. In soils, flagellates are also important, followed by naked amoebae, testate amoebae, and ciliates. Many of these protists feed on their prey by phagocytosis, in which the prey particle is engulfed into a food vacuole into which digestive enzymes are released. This mechanism of grazing explains many factors affecting grazing rates, such as prey numbers, size, and composition. Ingestion rates increase with prey numbers before reaching a maximum, similar to the Michaelis–Menten equation describing uptake as a function of substrate concentration. Protists generally eat prey that are about ten-fold smaller than they are. In addition to flagellates, ciliates and dinoflagellates are often important predators in the microbial world and are critical links between microbial food chains and larger organisms Many protists are capable of photosynthesis. In some cases, the predator benefits from photosynthesis carried out by engulfed, but undigested photosynthetic prey or its chloroplasts. Although much can be learnt from the morphology of large protists, small protists (<10 μ‎m) often cannot be distinguished by morphology, and as seen several times in this book, many of the most abundant and presumably important protists are difficult to cultivate, necessitating the use of cultivation-independent methods analogous to those developed for prokaryotes. Instead of the 16S rRNA gene used for bacteria and archaea, the 18S rRNA gene is key for protists. Studies of this gene have uncovered high diversity in natural protist communities and, along with sequences of other genes, have upended models of eukaryote evolution. These studies indicate that the eukaryotic Tree of Life consists almost entirely of protists, with higher plants, fungi, and animals as mere branches.

AbstractTornado Cash, the most popular non-custodial coin mixer on Ethereum, is widely used to protect the privacy of addresses. However, some inappropriate transaction behaviors in Tornado Cash mixing mechanism lead to the risk of privacy leakage. More specifically, the malicious attackers can link multiple addresses of the same users according to the transaction data. Motivated by the above problem, this paper systematically analyzes the privacy issues of Tornado Cash for the first time. In this paper, we give the macroscopic analysis of Tornado Cash based on the on-chain data and formalize two types of transaction patterns. Focus on the presented transaction patterns, we propose three heuristic clustering rules to link the users’ addresses, which reduce the size of users’ anonymity set. Finally, we perform the experiment on real Tornado Cash transaction data to describe the effectiveness of the proposed clustering rules.

AbstractSmart farming contributes to exponential income growth, enhanced decision making, better services and products, as well as productivity and profitability. Nowadays, numerous agricultural technology providers are entering the market, focusing on aggregating farmers’ data. But many farmers, especially smallholders, do not benefit from the sharing and exchange of this data, which leaves them feeling disempowered. Until today, ethical considerations were often side-lined because gathering more data was seen as necessary, and concerns about how data might be abused or misused were only subsequently considered. However, with the increase of big data in smart farming, it is more essential than ever to focus on the ethical aspects of data governance (access, control, consent) and practices. Therefore, these ethical questions will provide valuable insights into how data is being collected and used, for what purposes, how to bridge the digital divide, and how to create transparency and build trust between stakeholders. This chapter will focus on farmers’ perspectives and how they could actively participate in a more equitable data sharing and exchange in the agri-food value chain by contributing to the design of a fairer data governance framework. The adoption of agricultural codes of conduct is the example that will be explored.

Abstract This study was carried out in two villages, Kizapala and Kazole, of the Mkuranga District, in the Coast Region of Tanzania. The objective of the study was to establish the role of cassava as an adaptation crop to the changing climate and household food security. Primary data were obtained using household questionnaires and different participatory rural appraisal (PRA) techniques which included focus group discussions (FGDs), key informants and expert meetings. Secondary data were collected through a literature review, whereas temperature and rainfall data from 1984 to 2014 was obtained from the Tanzania Meteorological Agency (TMA). In each village, a sample size of 10% of all households was interviewed. Findings showed that 96% of respondents from Kazole village and 90% from Kizapala linked climate change with major climatic extreme events such as prolonged droughts and occasional abnormal floods. Analysis of temperature data for the last 30 years (1984-2014) revealed that temperature had significantly risen by a correlation coefficient of R² = 0.4936 for maximum and R² = 0.777 for minimum temperature. The field survey results closely correlated with findings from the analysis of TMA rainfall and temperature data. Findings revealed a decline in crop production which resulted in food shortages and livelihood insecurity in the study villages. The respondents in both villages consider cassava as a crop that is least affected by climate and environmental extremes, thus serves to ensure food availability and security in their households. As a result, growing cassava should be considered as an adaptation strategy to climate change and variability now and in the future. Improving cassava production, processing, marketing and value chain infrastructures is, therefore, crucial for enhancing sustainable adaptation in the district.

AbstractThe health of people, the health of animals, including aquatic species and insects, the health of plants and the environment, including soils, are connected, and this is captured by the One Health approach. The Covid-19 pandemic has laid bare this interconnectedness. Zoonotic infectious disease spillover occurs most commonly where the agri-food system interfaces with natural ecosystems, as this is where humans, domesticated animals and wildlife interact. On the other hand, deficient human health adds to the favorable conditions for pathogen transmission. There are direct and indirect effects of pandemics on food systems and health; disease outbreaks disrupt overall mobility, the workforce and the supply chain. Such disruptions affect food security and, in many cases, workers’ income or the economic viability of businesses in the food system. In this chapter, we discuss the link between global food security and One Health, and how to prepare for, and minimize the chance of, future pandemics. Reducing the likelihood of spillover and onwards transmission risk of pathogens can be served through (i) reducing the need for natural habitat disruption, (ii) smart management of both sides of the interface between natural ecosystems and the agri-food system, and vigilance at the human-animal interface within the agri-food system, and (iii) improving overall human, animal and environmental health.

AbstractChimeric antigen receptor (CAR) is a synthetic transmembrane protein expressed at the surface of immune effector cells (IECs) that are reprogrammed either in vitro or in vivo (June et al. 2018; June and Sadelain 2018). Techniques for genetic engineering of autologous or allogeneic IECs are described in the next chapter. The synthetic CAR incorporates several functional domains. The extracellular domain is composed of a single chain variable fragment (ScFV) of immunoglobulin and recognizes the “tumour” antigen. The clinical relevance of the selected tumour antigen—with a view to minimize “on-target/off-tumour” side effects—is discussed in the third chapter of this section. Bispecific and trispecific CARs are currently being evaluated in preclinical and early clinical trials (Bielamowicz et al. 2018; Shah et al. 2020). The use of an immunoglobulin domain as the ligand of the target antigen means that recognition is not restricted to HLA antigens and that CAR-T cells are universally applicable as opposed to T cell receptor (TCR) transgenic T cells that recognize antigenic peptides presented in the context of a defined major histocompatibility complex (MHC), limiting clinical applications to subsets of patients with defined HLA typing. The intracellular domain is composed of the intracellular domain of the zeta chain of the CD3 component of the TCR, which will trigger signalling when the CAR engages the targeted ligand. The transmembrane region links the two extracellular and intracellular domains through the cell membrane and plays an important role in determining the conformation and flexibility of the CAR and its ability to efficiently bind the targeted antigen/epitope. Association of only these three functional domains characterized first generation CARs, as described in the original publications (Kuwana et al. 1987; Eshhar et al. 1993). However, full activation of T cells requires the addition of one (second generation CARs) or two (third generation CARs) domains from costimulatory molecules, such as CD28, 4-1BB/CD137, or OX40/CD134, that provide the T cell costimulatory signal. Currently approved CAR-T cells are second generation CAR-T cells; as an illustration, the CAR in tisagenlecleucel contains a 4-1BB domain, while the CAR in axicabtagene ciloleucel contains a CD28 domain. The nature of the costimulatory domain influences the ability of CAR-T cells to expand or persist (limit T cell exhaustion) in vivo after infusion into the patient, although it is unclear how this translates clinically and affects disease control, occurrence of adverse events, and overall survival due to the lack of head-to-head comparison between approved products. Finally, fourth generation CAR-T cells have been developed for preclinical projects. These cells, named armoured CAR cells or T cells redirected for universal cytokine-mediated killing (TRUCKS), encode not only a CAR (usually with one costimulatory domain, such as in second generation CARs) but also a cytokine, interleukin, pro-inflammatory ligand, or chemokine that will counteract the immune suppressive microenvironment that prevails in most solid tumours (Eshhar et al. 1993; Chmielewski and Abken 2015).

Until quite recently, there was relatively little reliable quantitative information on the relationship of stress to structure, primarily because of the uncontrolled manner in which elastomeric networks were generally prepared. Segments close together in space were linked irrespective of their locations along the chain trajectories, thus resulting in a highly random network structure in which the number and locations of the cross-links were essentially unknown. Such a structure is shown in figure 10.1. New synthetic techniques are now available, however, for the preparation of “model” polymer networks of known structure. More specifically, if networks are formed by end linking functionally terminated chains instead of haphazardly joining chain segments at random, then the nature of this very specific chemical reaction provides the desired structural information. Thus, the functionality of the cross links is the same as that of the end-linking agent, and the molecular weight Mc between cross-links and the molecular weight distribution are the same as those of the starting chains prior to their being end-linked. An example is the reaction shown in figure 10.2, in which hydroxyl-terminated chains of poly(dimethylsiloxane) (PDMS) are end-linked using tetraethyl orthosilicate. Characterizing the un-cross-linked chains with respect to molecular weight Mn and molecular weight distribution, and then carrying out the specified reaction to completion, gives elastomers in which the network chains have these characteristics; in particular, a molecular weight Mc between cross-links equal to Mn, a network chain-length distribution equal to that of the starting chains, and cross-links having the functionality of the end-linking agent. It is also possible to use chains having a known number of potential cross-linking sites placed as side chains along the polymer backbone, so long as their distribution is known as well. Because of their known structures, such model elastomers are now the preferred materials for the quantitative characterization of rubberlike elasticity. Such very specific cross-linking reactions have also been shown to be useful in the preparation of liquid-crystalline elastomers. Trifunctional and tetrafunctional PDMS networks prepared in this way have been used to test the molecular theories of rubber elasticity with regard to the increase in non-affineness of the network deformation with increasing elongation.

Polyphosphazenes comprise by far the largest class of inorganic macromolecules. At least 700 different polymers of this type have been synthesized, with a range of physical and chemical properties that rivals that known hitherto only for synthetic organic macromolecules. Most polyphosphazenes have the general molecular structure. The polymer backbone consists of alternating phosphorus and nitrogen atoms, with two side groups, R, being attached to each phosphorus. The side groups may be organic, organometallic, or inorganic units. Each macromolecule typically contains from 100 to 15,000 or more repeating units linked end to end, which means that (depending on the organic side groups) the highest molecular weights are in the range of 2 million to 10 million. The bonding structure in the backbone is formally represented as a series of alternating single and double bonds. However, this formulation is misleading. Structural measurements suggest that all the bonds along the chain are equal or nearly equal in length, but without the extensive conjugation found in organic polyunsaturated materials. This anomaly will be discussed later. In addition to linear polyphosphazenes with one type of side group, other molecular architectures have also been assembled. These include polyphosphazenes in which two or more different side groups, R1 and R2, are arrayed along the chain in random, regular, or block distributions. Other species exist with short phosphazene branches linked to phosphorus atoms in the main chain. Also available are macromolecules in which carbon or sulfur replace some of the phosphorus atoms in the skeleton. Star-geometry structures, using the symbolism defined, are also accessible. A new and growing area is the field of phosphazene-organic and phosphazene-polysiloxane hybrid linear copolymers, and comb copolymers of the types. In addition, polymers are known in which six-membered phosphazene rings are side groups linked to organic polymers, and where phosphazene rings are linked by organic connector groups to form cyclolinear or cyclomatrix materials.

A polymer is a very-long-chain macromolecule in which hundreds or thousands of atoms are linked together to form a one-dimensional array. The skeletal atoms usually bear side groups, often two in number, which can be as small as hydrogen, chlorine, or fluorine atoms or as large as aryl or long-chain alkyl units. Polymers are different from other molecules because the long-chain character allows the chains to become entangled in solution or in the solid state or, for specific macromolecular structures, to become lined up in regular arrays in the solid state. These molecular characteristics give rise to solid-state materials properties, such as strength, elasticity, fiber-forming qualities, or film-forming properties, that are not found for small molecule systems. The molecular weights of polymers are normally so high that, for all practical purposes, they are nonvolatile. These characteristics underlie the widespread use of polymers in all aspects of modern technology. Attempts to understand the relationship between the macromolecular structure and the unusual properties characterize much of the fundamental science in this field. Polymers are among the most complicated molecules known. They may contain thousands of atoms in the main chain, plus complex clusters of atoms that form the side groups attached to the skeletal units. How, then, can we depict such molecules in a manner that is easy to comprehend? First, an enormous simplification can be achieved if we remember that most synthetic polymers contain a fairly simple structure that repeats over and over down the chain. This simplest repetitive structure is known as the repeating unit, and it provides the basis for an uncomplicated representation of the structure of the whole polymer. For example, suppose that a polymer consists of a long chain of atoms of type A, to which are attached side groups, R. The polymer chain can be represented by the formula shown in 1.1. The two horizontal lines represent the bonds of the main chain. The brackets (or parentheses) indicate that the structure repeats many times. The actual number of repeating units present is normally not specified, but is represented by the subscript, n.

Chapter 1 reviews basic principles of protein structure—the nature of proteins as polymers of amino acids, the variety of amino acids, and the way in which the physicochemical properties of amino acid side chains influence the folding of a polymer into a three-dimensional protein with specific functional properties. Whereas the main chain polypeptide is linked together by covalent bonds, the three-dimensional structure of native state proteins is mainly stabilized by a multitude of noncovalent, weakly polar interactions. After securing the base camp with this brief overview of protein structure, the subsequent chapters explore the functional properties of hemoglobin, the biophysical mechanisms underlying such properties, and the physiological role of hemoglobin in respiratory gas transport.

Recently, the phenomenon of out-of-plane bending (OPB) fatigue of mooring chain links emerged as an important parameter in the fatigue assessment of mooring lines. Vessel motions induce a bending moment at the top chain of a mooring line. This bending moment induces alternating local stresses in the link and thus contributes to fatigue damage of those links. High pretension mooring systems are particularly sensitive to this phenomenon, since a small vessel motion combined with a high tension results in a relatively large bending moment in the upper mooring chain links. In mooring systems with high pre-tensions, this damage is of much greater magnitude than the fatigue damage induced by tension-tension loading only. An extensive study has been executed to investigate the fatigue life of mooring chain in deep water systems. This paper presents the calculation procedure to include the effects of local chain bending in the overall mooring line fatigue analysis. It was concluded that despite the complexity of the OPB issue, it is a phenomenon that can be incorporated in the mooring analyses by means of numerical procedures. The developed method is based on extensive Finite Element Method (FEM) analyses of chain links. Models of multiple chain links have been used that take into account the plastic-elastic properties of the material and contact friction between chain links. The FE models are used to derive empirical relations, between load angles, interlink angles, bending moments and stresses. These calculations were made for different combinations of line tension, interlink friction and chain size. The results were stored in a database to gain insight in the out-of-plane bending phenomenon. This database provides empirical formulas to lead to the local stress in different points on a chain link. These empirical formulas are used to translate floater (vessel or buoy) motions into local stress variations and fatigue damages in chain links. The long-term motion behaviour of the floater is known, the long term tension and bending stress ranges can be obtained and thus a fatigue damage of the chain links can be calculated.

Abstract Fatigue design recommendations provided by API RP 2SK, ISO 19901-7 and DNVGL-OS-E301 for studless chain links are based on data of steel grades R3 and R4 and mainly of link diameter of 76mm. Mooring systems utilising larger diameter links and higher strength steels (e.g. grade R5) are now in operation. Consequently, industry expressed a need for fatigue test data in seawater of higher steel grade and larger diameter chain to confirm whether the existing fatigue design guidance is applicable. A joint industry project (JIP) was launched by TWI to investigate fatigue performance of high strength and large diameter mooring chain in free corrosion seawater. A test rig was designed and manufactured which was capable of testing studless mooring chain links up to 127mm link diameter under tension-tension loading. Twenty-three full-scale fatigue tests were conducted on high strength steel grades (R4 and R5) and larger diameter chains (76mm and 127mm) generating 72 link failures. Magnetic particle inspections (MPI) were carried out to characterise the location of cracking, crack size and crack growth rate. This paper describes the results obtained in the JIP.

Abstract A procedure is developed to optimize planar mechanism type. A Genetic Algorithm is used to cycle populations of kinematic chain link adjacency matrices, through selection, crossover, and mutation. During this optimization, fit kinematic chains survive while unfit kinematic chains do not. Upon convergence, synthesized kinematic chains of high fitness remain. This technique was lead to be called the Genetic Algorithm for Type Synthesis (GATS). GATS introduces four new ideas for the type synthesis of mechanisms. First, it does not permute all possible kinematic chains. It searches for the best kinematic chains depending on a designer’s specifications. Second, larger size mechanisms can be generated because of the genetic algorithm’s evolutionary naturalness. Third, a novel approach was applied to genetic algorithms to allow the encodings to mutate in size. This allowed for addition or elimination of links in kinematic chains during evolution. Forth, a new property was deduced from mechanism topography that describes the mechanism design flexibility.

In this paper we propose a method that includes stochastic and robust models for designing the network structure of a three-tiered supply chain involving suppliers, manufacturers and retailers under random demands of markets and by considering disruption probabilities in the procurement facilities and connecting links of the chain. Demands of the markets are as assumed to be random variables with normal distribution and the disruption of the chain is formulated by defining different scenarios. Having substitutable facilities and extra production capacities makes it possible to overcome the negative effects of demand fluctuations and disruption of facilities. First we determine the optimal number, location and capacity of facilities in the first and third tiers and the best flow of material and product throughout the chain in a way to maximize the expected profit from the chain. Then to reduce the difference between the performances of the chain in different scenarios, we propose the ISP-Robust technique based on P-Robust technique to make the model robust. We discuss the differences and advantages of this technique in comparison to the P-Robust technique. We illustrate our method using data from the petrochemical industry.

Experiences show that mooring line failures have occurred due to crack propagation in chain links. Moreover, the crack propagation is accelerated by corrosion. To maintain the safety of floating structures in a long-term period of, say 20–30 years, it is therefore crucial that these chain links are properly designed as well as inspected and repaired during operation. The aim of this paper is to establish a reliability-based formulation for assessing mooring chains under the deterioration due to combined fatigue cracking and corrosion wastage. The crack growth in chain links has been modelled using the 2-dimensional Paris-Erdogan equation, which is validated by comparison with the SN data on a reliability basis. The corrosion is treated by considering the diameter reduction and the fatigue crack growth rate, using three zones of corrosion, namely the splash, catenary and bottom zones. A fatigue reliability case study of studless chain links is carried out considering various system models and proper correlation between links. The material correlation is modelled by splitting variables for the global and local effect. Accumulated failure probabilities of one year up to twenty years have been calculated to illustrate the effect of corrosion on fatigue reliability. A sensitivity study has been carried out on the initial crack size, the crack aspect ratio and the material correlation between links, when applying the fracture mechanics approach. Based on the case study, it has been found that the splash zone has an important effect on the failure probability of the entire mooring line, especially under corrosion of long time.

Genetically abnormal, dysfunctional fibrinogen variants may be used as unique models for studies of structure-function relationships both in vitro and in vivo. Out of the over kO so far structurally elucidated abnormal fibrinogens only 4 have an amino acid substitution in the Bg-chain. These variants are named Fibrinogen Pontoise, Nev York I, Christchurch II and Seattle I.Fibrinogens Seattle I and Christchurch II are slow-clotting fibrinogens which on thrombin-treatment release only half the normal amount of fibrinopeptide B and therefore were expected to contain an amino acid substitution close to the thrombin cleavage site in the Bβ-chain. In order to sequence the abnormal Bg-chains the fibrinogens were cleaved with thrombin and cyanogen bromide. The abnormal Bβ-chain components were isolated from the mercapto-lysed-pyridylethylated N-terminal disulfide knots. After pyroglu-tamyl-peptidase digestion the Bβ 14 Arg→Cys substitutions could be demonstrated for both variants by direct N-terminal sequence analysis. The form of the cyst(e)ine residue was determined by amino acid analysis of the alkylated native fibrinogen. As no alkylated cysteine was detected it was concluded that Bβ 14 Cys participates in a disulfide bridge.Fibrinogens Seattle I and Christchurch II are the first two elucidated fibrinogens with substitutions at the Bβ-chain thrombin cleavage site. Surprisingly, both the thrombin and Reptilase times are prolonged. It may be assumed that the half-cystine residues in position 14 of the two Bβ-chains within one fibrinogen molecule are disulfide-linked to each other, in an analogous way to that already established for the half-cystine residues in position 16 of the Aα-chains of several abnormal fibrinogens.This additional disulfide bridge might change the conformation and charge in the N-terminal region sufficiently to explain the prolonged clotting times. Furthermore, this bridge would provide the evidence for the parallel arrangement of the Bβ-chains at the fibrinogen N-terminus in a similar way as previously shown for the Aα-chains.

This research is part of a larger project which aims at developing a tool to help designers create effective GD&T schemas. The first step towards this goal is to determine the particular directions in which dimensions and tolerances need to be controlled. These directions we label here as “Directions of (Dimensional) Control” or DoC for short. Regardless of whether one uses chain dimensioning, reference dimensioning or geometric tolerancing, all size and basic dimensions of position line up in a finite number of directions or Directions of Control. This paper presents an approach for automatically identifying the directions of control from CAD models of mechanical parts. The only input to the system is the geometry of parts or assemblies in STEP file format. The analysis is done part by part for an assembly. First, planar and cylindrical features are recognized and their normal/axes extracted. The extracted features are then organized into groups of parallel normal or axes directions. Cylindrical features can belong to two or more Directions of Control, while planar features belong can only belong to one. Features in each DoC are then ordered based on perpendicular relative distances. Each ordered feature list forms a linear chain in which nodes represent features and links are attributed with relative distance to the nearest neighbors on each side. DoC chains are related to each other by relative orientation. Therefore, the chains are combined into a unified graph, using the junction nodes to contain the relative orientation between the chains. The extracted Directions of Control can be output in both textual and graphical form. Although the primary motivation for automatic DoC graph generation is computer assisted tolerancing and automatic tolerance analysis, the paper also discusses other applications in manufacturing.

Abstract The paper proposes that the UK should be the global centre of hydrogen production and explores why and how this ambition could be achieved. The paper focuses on what government and industry need to do to realise this dream. We explain the technology, commerciality and legislation required in order to raise ambitions and create a sense of urgency within the hydrogen community. The paper justifies this bold statement, highlighting the fundamentals that the UK enjoys and compares these against other rival global centres, by considering the existing infrastructure whilst explaining the merits of the UKs diverse gas supply chain. The paper also explores and debunks technology readiness and perceived risks associated with hydrogen production. The paper concludes that the UK should adopt a bolder ambition for hydrogen, and suggests how the UK can move forward faster with recommendations for new commercial frameworks. The paper also demonstrates that the current perceived risks linked with blue hydrogen development, both technological and subsurface, are overstated. The paper sets out a commercial landscape that would enable rapid hydrogen development. The paper focuses on blue hydrogen production infrastructure, setting a timeframe of achievability whilst allowing for demand side influences. The paper also considers how to future-proof hydrogen infrastructure to facilitate green hydrogen co-production. The paper highlights the possible errors of decommissioning depleted oil fields where carbon dioxide (CO2) storage could be used to extend the life of the facilities, with possible enhanced oil recovery as an upside. The paper discusses how the liabilities currently hindering integrated hydrogen developments are more theoretical than real, by consideration of minimised leak paths and corrosion mechanisms. The paper also explains why these liabilities should ultimately be underwritten by government institutions.

Three years ago, several mooring chains of an off-loading buoy failed after only 8 months of service. These chains were designed according to conventional fatigue assessment using API RP 2SK T-N curves to a fatigue life or 20 years with a factor of safety equal to 3 on life. Of particular interest is that the mooring chain failure underwent significant mooring chain motions that caused interlink rotations. Although traditionally neglected, these interlink rotations, when combined with significant chain tensions can cause bending stresses in the chain links (See Figure 1). This recently identified phenomena, Out-of-Plane Bending (OPB), explains the extensive fatigue damage causing the mooring chains of the off-loading buoy to fail [3][4][5]. References [3] and [4] document full scale tests of the OPB mechanism using a full scale test frame with the ability of applying inter-link rotation to a pre-tensioned chain. This testing confirmed that interlink rotations with a constant tension load can result in significantly high stresses. OPB stresses were measured on four different chain sizes of various grades: 1) 81 mm Studded Grade R3S, 2) 107 mm Stud-less Grade RQ3, 3) 124 mm Stud-less Grade R4, and 4) 146 mm Stud-less Grade RQ4, Grade R3 in [3] and [4], but no actual fatigue tests were performed. References [3] and [5] document analytical and computational efforts to explain and quantify the OPB stresses. In this paper, special focus is placed on obtaining actual fatigue failures of chains from OPB loading. Smaller chain sizes (40 mm) are used to accommodate the load limits of the testing frame. To mimic the actual loading as close as possible, sub size models of actual chainhawses were used in the testing. Two chainhawses were used: 1) the chainhawse has internal curvature where a link rests on the intrados, similar to offloading buoy that failed in eight months, and 2) a straight chainhase, a design that is in use today with demonstrated improved fatigue performance over the curved chainhawse. OPB stresses are measured and reported. Fatigue loading in the OPB mode was applied for several configurations. The two chainhawse exhibit very different stress levels and fatigue performance. An empirical relationship previously reported in [3][4][5] is compared to the measured OPB stresses with mixed results. Although limited in number, the fatigue tests indicate that overall the chain fatigue performance is at or above the B1 DnV curve. The BS B1 curve is also compared.

Recognizing the widespread concern that disruptions created by technology have not yet benefited middle- and low-income households, this study explores the potential of PropTech to positively impact the housing challenges in the region, with a particular focus on the poor or vulnerable populations. This study reveals several emerging trends that offer insight to those thinking about digital transformation in the housing and real estate sector for Latin America and the Caribbean and serve as the foundation for more research. PropTech startups are defined broadly as fast-growing actors that are developing technology-based business models for housing real estate markets. This includes companies operating on most phases of the housing value chain, from the housing units supply side (land, construction, access to services, and home improvement) to the demand side (financing, renting, buying, selling, and commercializing units). PropTech startups mainly address two key issues in the traditional real estate market: lack of transparency and processes inefficiencies. Reducing costs and making information available equalizes the markets playing field. The opportunity for PropTech startups to develop business models that cover lower income brackets is still largely unexplored. Currently, profitable businesses are mostly serving high-income bracket groups. Thus, large-scale solutions that would make investing in the low-income segment profitable remain an opportunity for PropTech companies to target. Also, opportunities remain for startups to explore housing solutions that strengthen adaptation to climate change and curb harmful environmental impact through technology innovations through retrofitting efforts or the repurposing of existing units. The report pays special attention to the different links in the value chain and highlights success stories that are having an impact on the current housing market, resulting in a snapshot of scalable, private-sector-led solutions currently deployed to solve pressing housing problems in the region.

The proposed research was directed at determining the activation/binding domains and gene regulation of the PBAN-R’s thereby providing information for the design and screening of potential PBAN-R-blockers and to indicate possible ways of preventing the process from proceeding to its completion. Our specific aims included: (1) The identification of the PBAN-R binding domain by a combination of: (a) in silico modeling studies for identifying specific amino-acid side chains that are likely to be involved in binding PBAN with the receptor and; (b) bioassays to verify the modeling studies using mutant receptors, cell lines and pheromone glands (at tissue and organism levels) against selected, designed compounds to confirm if compounds are agonists or antagonists. (2) The elucidation ofthemolecular regulationmechanisms of PBAN-R by:(a) age-dependence of gene expression; (b) the effect of hormones and; (c) PBAN-R characterization in male hair-pencil complexes. Background to the topic Insects have several closely related G protein-coupled receptors (GPCRs) belonging to the pyrokinin/PBAN family, one with the ligand pheromone biosynthesis activating neuropeptide or pyrokinin-2 and another with diapause hormone or pyrokinin-1 as a ligand. We were unable to identify the diapause hormone receptor from Helicoverpa zea despite considerable effort. A third, related receptor is activated by a product of the capa gene, periviscerokinins. The pyrokinin/PBAN family of GPCRs and their ligands has been identified in various insects, such as Drosophila, several moth species, mosquitoes, Triboliumcastaneum, Apis mellifera, Nasoniavitripennis, and Acyrthosiphon pisum. Physiological functions of pyrokinin peptides include muscle contraction, whereas PBAN regulates pheromone production in moths plus other functions indicating the pleiotropic nature of these ligands. Based on the alignment of annotated genomic sequences, the primary and secondary structures of the pyrokinin/PBAN family of receptors have similarity with the corresponding structures of the capa or periviscerokinin receptors of insects and the neuromedin U receptors found in vertebrates. Major conclusions, solutions, achievements Evolutionary trace analysisof receptor extracellular domains exhibited several class-specific amino acid residues, which could indicate putative domains for activation of these receptors by ligand recognition and binding. Through site-directed point mutations, the 3rd extracellular domain of PBAN-R was shown to be critical for ligand selection. We identified three receptors that belong to the PBAN family of GPCRs and a partial sequence for the periviscerokinin receptor from the European corn borer, Ostrinianubilalis. Functional expression studies confirmed that only the C-variant of the PBAN-R is active. We identified a non-peptide agonist that will activate the PBAN-receptor from H. zea. We determined that there is transcriptional control of the PBAN-R in two moth species during the development of the pupa to adult, and we demonstrated that this transcriptional regulation is independent of juvenile hormone biosynthesis. This transcriptional control also occurs in male hair-pencil gland complexes of both moth species indicating a regulatory role for PBAN in males. Ultimate confirmation for PBAN's function in the male tissue was revealed through knockdown of the PBAN-R using RNAi-mediated gene-silencing. Implications, both scientific and agricultural The identification of a non-peptide agonist can be exploited in the future for the design of additional compounds that will activate the receptor and to elucidate the binding properties of this receptor. The increase in expression levels of the PBAN-R transcript was delineated to occur at a critical period of 5 hours post-eclosion and its regulation can now be studied. The mysterious role of PBAN in the males was elucidated by using a combination of physiological, biochemical and molecular genetics techniques.

Campylobacter spp. are the most common bacterial cause of foodborne illness in the UK, with chicken considered to be the most important vehicle for this organism. The UK Food Standards Agency (FSA) agreed with industry to reduce Campylobacter spp. contamination in raw chicken and issued a target to reduce the prevalence of the most contaminated chickens (those with more than 1000 cfu per g chicken neck skin) to below 10 % at the end of the slaughter process, initially by 2016. To help monitor progress, a series of UK-wide surveys were undertaken to determine the levels of Campylobacter spp. on whole UK-produced, fresh chicken at retail sale in the UK. The data obtained for the first four years was reported in FSA projects FS241044 (2014/15) and FS102121 (2015 to 2018). The FSA has indicated that the retail proxy target for the percentage of highly contaminated raw whole retail chickens should be less than 7% and while continued monitoring has demonstrated a sustained decline for chickens from major retailer stores, chicken on sale in other stores have yet to meet this target. This report presents results from testing chickens from non-major retailer stores (only) in a fifth survey year from 2018 to 2019. In line with previous practise, samples were collected from stores distributed throughout the UK (in proportion to the population size of each country). Testing was performed by two laboratories - a Public Health England (PHE) laboratory or the Agri-Food & Biosciences Institute (AFBI), Belfast. Enumeration of Campylobacter spp. was performed using the ISO 10272-2 standard enumeration method applied with a detection limit of 10 colony forming units (cfu) per gram (g) of neck skin. Antimicrobial resistance (AMR) to selected antimicrobials in accordance with those advised in the EU harmonised monitoring protocol was predicted from genome sequence data in Campylobacter jejuni and Campylobacter coli isolates The percentage (10.8%) of fresh, whole chicken at retail sale in stores of smaller chains (for example, Iceland, McColl’s, Budgens, Nisa, Costcutter, One Stop), independents and butchers (collectively referred to as non-major retailer stores in this report) in the UK that are highly contaminated (at more than 1000 cfu per g) with Campylobacter spp. has decreased since the previous survey year but is still higher than that found in samples from major retailers. 8 whole fresh raw chickens from non-major retailer stores were collected from August 2018 to July 2019 (n = 1009). Campylobacter spp. were detected in 55.8% of the chicken skin samples obtained from non-major retailer shops, and 10.8% of the samples had counts above 1000 cfu per g chicken skin. Comparison among production plant approval codes showed significant differences of the percentages of chicken samples with more than 1000 cfu per g, ranging from 0% to 28.1%. The percentage of samples with more than 1000 cfu of Campylobacter spp. per g was significantly higher in the period May, June and July than in the period November to April. The percentage of highly contaminated samples was significantly higher for samples taken from larger compared to smaller chickens. There was no statistical difference in the percentage of highly contaminated samples between those obtained from chicken reared with access to range (for example, free-range and organic birds) and those reared under standard regime (for example, no access to range) but the small sample size for organic and to a lesser extent free-range chickens, may have limited the ability to detect important differences should they exist. Campylobacter species was determined for isolates from 93.4% of the positive samples. C. jejuni was isolated from the majority (72.6%) of samples while C. coli was identified in 22.1% of samples. A combination of both species was found in 5.3% of samples. C. coli was more frequently isolated from samples obtained from chicken reared with access to range in comparison to those reared as standard birds. C. jejuni was less prevalent during the summer months of June, July and August compared to the remaining months of the year. Resistance to ciprofloxacin (fluoroquinolone), erythromycin (macrolide), tetracycline, (tetracyclines), gentamicin and streptomycin (aminoglycosides) was predicted from WGS data by the detection of known antimicrobial resistance determinants. Resistance to ciprofloxacin was detected in 185 (51.7%) isolates of C. jejuni and 49 (42.1%) isolates of C. coli; while 220 (61.1%) isolates of C. jejuni and 73 (62.9%) isolates of C. coli isolates were resistant to tetracycline. Three C. coli (2.6%) but none of the C. jejuni isolates harboured 23S mutations predicting reduced susceptibility to erythromycin. Multidrug resistance (MDR), defined as harbouring genetic determinants for resistance to at least three unrelated antimicrobial classes, was found in 10 (8.6%) C. coli isolates but not in any C. jejuni isolates. Co-resistance to ciprofloxacin and erythromycin was predicted in 1.7% of C. coli isolates. 9 Overall, the percentages of isolates with genetic AMR determinants found in this study were similar to those reported in the previous survey year (August 2016 to July 2017) where testing was based on phenotypic break-point testing. Multi-drug resistance was similar to that found in the previous survey years. It is recommended that trends in AMR in Campylobacter spp. isolates from retail chickens continue to be monitored to realise any increasing resistance of concern, particulary to erythromycin (macrolide). Considering that the percentage of fresh, whole chicken from non-major retailer stores in the UK that are highly contaminated (at more than 1000 cfu per g) with Campylobacter spp. continues to be above that in samples from major retailers more action including consideration of interventions such as improved biosecurity and slaughterhouse measures is needed to achieve better control of Campylobacter spp. for this section of the industry. The FSA has indicated that the retail proxy target for the percentage of highly contaminated retail chickens should be less than 7% and while continued monitoring has demonstrated a sustained decline for chickens from major retailer stores, chicken on sale in other stores have yet to meet this target.

Macroeconomic summary Several factors contributed to an increase in projected inflation on the forecast horizon, keeping it above the target rate. These included inflation in December that surpassed expectations (5.62%), indexation to higher inflation rates for various baskets in the consumer price index (CPI), a significant real increase in the legal minimum wage, persistent external and domestic inflationary supply shocks, and heightened exchange rate pressures. The CPI for foods was affected by the persistence of external and domestic supply shocks and was the most significant contributor to unexpectedly high inflation in the fourth quarter. Price adjustments for fuels and certain utilities can explain the acceleration in inflation for regulated items, which was more significant than anticipated. Prices in the CPI for goods excluding food and regulated items also rose more than expected. This was partly due to a smaller effect on prices from the national government’s VAT-free day than anticipated by the technical staff and more persistent external pressures, including via peso depreciation. By contrast, the CPI for services excluding food and regulated items accelerated less than expected, partly reflecting strong competition in the communications sector. This was the only major CPI basket for which prices increased below the target inflation rate. The technical staff revised its inflation forecast upward in response to certain external shocks (prices, costs, and depreciation) and domestic shocks (e.g., on meat products) that were stronger and more persistent than anticipated in the previous report. Observed inflation and a real increase in the legal minimum wage also exceeded expectations, which would boost inflation by affecting price indexation, labor costs, and inflation expectations. The technical staff now expects year-end headline inflation of 4.3% in 2022 and 3.4% in 2023; core inflation is projected to be 4.5% and 3.6%, respectively. These forecasts consider the lapse of certain price relief measures associated with the COVID-19 health emergency, which would contribute to temporarily keeping inflation above the target on the forecast horizon. It is important to note that these estimates continue to contain a significant degree of uncertainty, mainly related to the development of external and domestic supply shocks and their ultimate effects on prices. Other contributing factors include high price volatility and measurement uncertainty related to the extension of Colombia’s health emergency and tax relief measures (such as the VAT-free days) associated with the Social Investment Law (Ley de Inversión Social). The as-yet uncertain magnitude of the effects of a recent real increase in the legal minimum wage (that was high by historical standards) and high observed and expected inflation, are additional factors weighing on the overall uncertainty of the estimates in this report. The size of excess productive capacity remaining in the economy and the degree to which it is closing are also uncertain, as the evolution of the pandemic continues to represent a significant forecast risk. margin, could be less dynamic than expected. And the normalization of monetary policy in the United States could come more quickly than projected in this report, which could negatively affect international financing costs. Finally, there remains a significant degree of uncertainty related to the duration of supply chocks and the degree to which macroeconomic and political conditions could negatively affect the recovery in investment. The technical staff revised its GDP growth projection for 2022 from 4.7% to 4.3% (Graph 1.3). This revision accounts for the likelihood that a larger portion of the recent positive dynamic in private consumption would be transitory than previously expected. This estimate also contemplates less dynamic investment behavior than forecast in the previous report amid less favorable financial conditions and a highly uncertain investment environment. Third-quarter GDP growth (12.9%), which was similar to projections from the October report, and the fourth-quarter growth forecast (8.7%) reflect a positive consumption trend, which has been revised upward. This dynamic has been driven by both public and private spending. Investment growth, meanwhile, has been weaker than forecast. Available fourth-quarter data suggest that consumption spending for the period would have exceeded estimates from October, thanks to three consecutive months that included VAT-free days, a relatively low COVID-19 caseload, and mobility indicators similar to their pre-pandemic levels. By contrast, the most recently available figures on new housing developments and machinery and equipment imports suggest that investment, while continuing to rise, is growing at a slower rate than anticipated in the previous report. The trade deficit is expected to have widened, as imports would have grown at a high level and outpaced exports. Given the above, the technical staff now expects fourth-quarter economic growth of 8.7%, with overall growth for 2021 of 9.9%. Several factors should continue to contribute to output recovery in 2022, though some of these may be less significant than previously forecast. International financial conditions are expected to be less favorable, though external demand should continue to recover and terms of trade continue to increase amid higher projected oil prices. Lower unemployment rates and subsequent positive effects on household income, despite increased inflation, would also boost output recovery, as would progress in the national vaccination campaign. The technical staff expects that the conditions that have favored recent high levels of consumption would be, in large part, transitory. Consumption spending is expected to grow at a slower rate in 2022. Gross fixed capital formation (GFCF) would continue to recover, approaching its pre-pandemic level, though at a slower rate than anticipated in the previous report. This would be due to lower observed GFCF levels and the potential impact of political and fiscal uncertainty. Meanwhile, the policy interest rate would be less expansionary as the process of monetary policy normalization continues. Given the above, growth in 2022 is forecast to decelerate to 4.3% (previously 4.7%). In 2023, that figure (3.1%) is projected to converge to levels closer to the potential growth rate. In this case, excess productive capacity would be expected to tighten at a similar rate as projected in the previous report. The trade deficit would tighten more than previously projected on the forecast horizon, due to expectations of an improved export dynamic and moderation in imports. The growth forecast for 2022 considers a low basis of comparison from the first half of 2021. However, there remain significant downside risks to this forecast. The current projection does not, for example, account for any additional effects on economic activity resulting from further waves of COVID-19. High private consumption levels, which have already surpassed pre-pandemic levels by a large margin, could be less dynamic than expected. And the normalization of monetary policy in the United States could come more quickly than projected in this report, which could negatively affect international financing costs. Finally, there remains a significant degree of uncertainty related to the duration of supply chocks and the degree to which macroeconomic and political conditions could negatively affect the recovery in investment. External demand for Colombian goods and services should continue to recover amid significant global inflation pressures, high oil prices, and less favorable international financial conditions than those estimated in October. Economic activity among Colombia’s major trade partners recovered in 2021 amid countries reopening and ample international liquidity. However, that growth has been somewhat restricted by global supply chain disruptions and new outbreaks of COVID-19. The technical staff has revised its growth forecast for Colombia’s main trade partners from 6.3% to 6.9% for 2021, and from 3.4% to 3.3% for 2022; trade partner economies are expected to grow 2.6% in 2023. Colombia’s annual terms of trade increased in 2021, largely on higher oil, coffee, and coal prices. This improvement came despite increased prices for goods and services imports. The expected oil price trajectory has been revised upward, partly to supply restrictions and lagging investment in the sector that would offset reduced growth forecasts in some major economies. Elevated freight and raw materials costs and supply chain disruptions continue to affect global goods production, and have led to increases in global prices. Coupled with the recovery in global demand, this has put upward pressure on external inflation. Several emerging market economies have continued to normalize monetary policy in this context. Meanwhile, in the United States, the Federal Reserve has anticipated an end to its asset buying program. U.S. inflation in December (7.0%) was again surprisingly high and market average inflation forecasts for 2022 have increased. The Fed is expected to increase its policy rate during the first quarter of 2022, with quarterly increases anticipated over the rest of the year. For its part, Colombia’s sovereign risk premium has increased and is forecast to remain on a higher path, to levels above the 15-year-average, on the forecast horizon. This would be partly due to the effects of a less expansionary monetary policy in the United States and the accumulation of macroeconomic imbalances in Colombia. Given the above, international financial conditions are projected to be less favorable than anticipated in the October report. The increase in Colombia’s external financing costs could be more significant if upward pressures on inflation in the United States persist and monetary policy is normalized more quickly than contemplated in this report. As detailed in Section 2.3, uncertainty surrounding international financial conditions continues to be unusually high. Along with other considerations, recent concerns over the potential effects of new COVID-19 variants, the persistence of global supply chain disruptions, energy crises in certain countries, growing geopolitical tensions, and a more significant deceleration in China are all factors underlying this uncertainty. The changing macroeconomic environment toward greater inflation and unanchoring risks on inflation expectations imply a reduction in the space available for monetary policy stimulus. Recovery in domestic demand and a reduction in excess productive capacity have come in line with the technical staff’s expectations from the October report. Some upside risks to inflation have materialized, while medium-term inflation expectations have increased and are above the 3% target. Monetary policy remains expansionary. Significant global inflationary pressures and the unexpected increase in the CPI in December point to more persistent effects from recent supply shocks. Core inflation is trending upward, but remains below the 3% target. Headline and core inflation projections have increased on the forecast horizon and are above the target rate through the end of 2023. Meanwhile, the expected dynamism of domestic demand would be in line with low levels of excess productive capacity. An accumulation of macroeconomic imbalances in Colombia and the increased likelihood of a faster normalization of monetary policy in the United States would put upward pressure on sovereign risk perceptions in a more persistent manner, with implications for the exchange rate and the natural rate of interest. Persistent disruptions to international supply chains, a high real increase in the legal minimum wage, and the indexation of various baskets in the CPI to higher inflation rates could affect price expectations and push inflation above the target more persistently. These factors suggest that the space to maintain monetary stimulus has continued to diminish, though monetary policy remains expansionary. 1.2 Monetary policy decision Banco de la República’s board of directors (BDBR) in its meetings in December 2021 and January 2022 voted to continue normalizing monetary policy. The BDBR voted by a majority in these two meetings to increase the benchmark interest rate by 50 and 100 basis points, respectively, bringing the policy rate to 4.0%.