Relevant Structural Elements Research Articles

Regulation of young-adult neurogenesis and neuronal differentiation by neural cell adhesion molecule 2 (NCAM2).

Adult neurogenesis persists in mammals in the neurogenic zones, where newborn neurons are incorporated into preexisting circuits to preserve and improve learning and memory tasks. Relevant structural elements of the neurogenic niches include the family of cell adhesion molecules (CAMs), which participate in signal transduction and regulate the survival, division, and differentiation of radial glial progenitors (RGPs). Here we analyzed the functions of neural cell adhesion molecule 2 (NCAM2) in the regulation of RGPs in adult neurogenesis and during corticogenesis. We characterized the presence of NCAM2 across the main cell types of the neurogenic process in the dentate gyrus, revealing different levels of NCAM2 amid the progression of RGPs and the formation of neurons. We showed that Ncam2 overexpression in adult mice arrested progenitors in an RGP-like state, affecting the normal course of young-adult neurogenesis. Furthermore, changes in Ncam2 levels during corticogenesis led to transient migratory deficits but did not affect the survival and proliferation of RGPs, suggesting a differential role of NCAM2 in adult and embryonic stages. Our data reinforce the relevance of CAMs in the neurogenic process by revealing a significant role of Ncam2 levels in the regulation of RGPs during young-adult neurogenesis in the hippocampus.

Prospects for the development of the logistics system and its structural elements

The purpose of the study is to carry out a critical analysis of the elements of the logistics system of a modern enterprise, identify their functional characteristics and connections, and develop proposals for the stages of forming an improved model of the logistics system. The article highlights the issues related to the specifics of the formation of an effective logistics system of the enterprise by its constituent elements. It has been proven that the modern design of the logistics system should have not only traditional, but also innovative elements for high-quality performance of logistics functions. On the basis of the conducted analysis, the use of the graphic method and generalization, the relevant structural elements of the logistics system were identified. The role of the stimulating function of management in the matter of encouraging logistics workers to perform their duties in a high-quality manner is defined. In this context, the experience of Poland is given as an example. Comparing the salary level of employees at different levels of procurement and logistics departments, identifying the advantages of their functional powers and status made it possible to develop directions for improving internal and external relations to ensure mutual positive influence and achieve the effect of synergy. Taking this into account, a scheme of stages of the formation of an improved logistics system has been developed. Based on the results of the analysis, a conclusion was made regarding the expediency of using traditional and innovative logistics tools, as well as modern dominants associated with the use of technical achievements. The application of the author's proposals will make it possible to form a high-quality logistics system of a modern enterprise on a practical level. This will ultimately have a positive effect on the management of logistics processes and ensure better efficiency and effectiveness of the enterprise.

Automated non-destructive integrity assessment of metal structures

Offshore windmills and pipeline networks are examples of strategic infrastructures used for the production of clean energy and for the storage and long-distance transportation of hydrocarbons, hydrogen and water. The relevant structural elements are mainly made of welded portions of steel pipes, which often interact with aggressive fluids and hostile environments. Material aging is thus accelerated and localized damage processes are promoted, harming the design safety factors. The structural health of such components can be monitored in operation, throughout their lifetime, by non-destructive testing performed by portable devices. The equipment at present available on the market permits to develop fully automated testing campaigns, overcoming the difficulties associated to large extension and difficult accessibility. The data collected on site can be transferred through virtual networks, to be evaluated and processed in order to permit the quantitative evaluations required by the optimization and the planning of repair and retrofit operations. This contribution discusses the potential offered by the current practice and illustrates the methodological adaptations that produce effective diagnostic tools in the outlined context.

ФЕНОМЕНОЛОГІЯ МУНІЦИПАЛІЗМУ: ДО ВИОКРЕМЛЕННЯ СТРУКТУРНИХ БЛОКОВИХ ЕЛЕМЕНТ

The article is devoted to the analysis of the structural construction of the phenomenology of modern municipalism with the use of a systematic set of methods of legal knowledge. The author believes that taking into account characterological substantive, functional, narrative, connotational, contextual and identification features of the phenomenology of modern municipalism allows not only to identify, comprehend and understand the systemic criteria that form, determine, actualize and transform the studied period in the phenomenological but also to identify the relevant structural block elements that form and constitute it, including ideological, doctrinal, social, normative, praxeological, psychological, behavioral and other blocks. The conclusion is substantiated that the municipalization of public and state life, as well as the municipalization of the legal system of the state is an important driving force in the process of formation of structural block elements of modern municipalism. It is a complex process of restructuring and reorientation of social, state and normative constants of development and functioning of society, state, legal system from the needs of the state to the needs and interests of a person, its groups and collectives - to optimize social, state, normative technologies of existence and development man in a state-organized society, proper provision of its rights and freedoms. At the same time, the author added to this list the current trends of constitutionalization of international law and internationalization of constitutional law, which provide the phenomenology of municipalism of international legal personality, accompany and ensure its formation and development at the level of a state, associations and international community. Legal obligations contained in multilateral international agreements. It is concluded that taking into account the characterological content, functional, narrative, connotational, contextual and identification features of the phenomenology of modern municipalism allows not only to identify, comprehend and understand the systemic criteria that form, determine, actualize and transform the studied period in the studied but also to identify the relevant structural block elements that form and constitute it, including ideological, doctrinal, social, normative, praxeological, psychological, behavioral and other blocks. Restructuring the existing mechanisms, based on state statism and the priority of state interests in the opposite direction of the actual opposite teleological dominants, is one of the main tasks of municipal reform in Ukraine.

The Tenant of Wildfell Hall: El künstlerroman femenino como modelo didáctico en la literatura inglesa

Este artículo se centra en el análisis de la novela de Anne Brönte The Tenant of Wildfell Hall (1848) considerando el fin didáctico propuesto por la autora y tomando como referencia uno de los principales modelos literarios del siglo XIX: el künstlerroman o novela del artista. Se propone aquí una puesta en valor de la menos reconocida de las hermanas Brönte, siguiendo la línea argumentativa de relevantes estudios sobre el tema, como Hirsh y Langland (1983), Losano (2003) o Ellis (2017). Si bien la novela de desarrollo tradicional es esencialmente masculina, en el que el artista se recluye en su “torre de marfil”, este no es el caso en esta obra, en la que la heroína artista decimonónica ha de debatirse entre su rol femenino y su pasión artística. Es más, Anne Brönte articula la lucha interna de la protagonista como modelo sutilmente transgresor de la encorsetada sociedad decimonónica. Para profundizar en el modelo de conducta transgresor ejemplificado en la figura de Helen, la protagonista de la obra, se realizará en primer lugar una breve contextualización de los géneros narrativos en los que se enmarca: el bildungsroman y el künstlerroman. A continuación, se analizarán tanto la estructura de la obra como los pasajes más determinantes que inciden en la representación de la mujer como artista para, finalmente, validar la tesis inicial.

Effects of ownership structure and corporate and family governance on dynamic capabilities in family firms

By combining the resource-and capabilities-based view and agency theory, this paper offers a framework within which to examine the nature of dynamic capabilities in family firms, and how they are affected by the ownership, governance and management structures. We focus on technology-based innovation capabilities, differentiating between sensing, seizing and transforming capabilities. We expand the analysis of family involvement, defined as the family firm owner's ability to influence firm behavior, identifying three distinct structures that underpin decision-making power and control capacity in family firms: the capital structure, the governance and management structure of the business; and the governance structure of the family itself. The empirical research was carried out on a sample of 748 family firms from the Spanish tourism industry. We find that the effects of these dimensions of family involvement on dynamic capabilities are asymmetric. A concentrated ownership structure with a high degree of family control and a substantial share of family wealth committed to the business are shown to have a negative effect. The management structure is shown to be the key body for fostering the accumulation of dynamic capabilities, although a high level of family involvement in the top management team and having a family member as CEO represent major barriers to this process. On the other hand, the board of directors and its composition appear not to be relevant structural elements. The most powerful structural factor in facilitating the development of innovation capabilities is the existence of an effective family board and the implementation of family management instruments. These mechanisms help to mitigate the negative effects of a family-controlled ownership and management structure. The findings represent a significant contribution to the literature on family firms, innovation management and corporate governance.

Refinement of the Catalyst Backbone of Chiral Intramolecular Silicon–Sulfur Lewis Pairs: Improved Enantioselectivity in the Diels–Alder Reaction of Cyclohexa‐1,3‐diene and Chalcone Derivatives

The preparation and NMR spectroscopic characterization of a family of axial chiral, sulfur‐stabilized silicon cations is reported. These silicon Lewis acids have been applied as catalysts in difficult enantioselective Diels–Alder reactions of cyclohexa‐1,3‐diene and representative chalcone derivatives. To gain better understanding of the relevant structural elements in these catalysts, their silepine backbone and the aryl thioether group have been systematically modified. These efforts have led to an improved catalyst that induces 53 % ee for chalcone and even 65 % ee for a more hindered derivative. These cyclohexa‐1,3‐diene Diels–Alder reactions are endo selective. However, the corresponding cyclopentadiene Diels–Alder reactions predominantly yield the exo cycloadducts with no enantioinduction.

Spatio-temporal hazard estimation in San Miguel volcano, El Salvador

Despite being one of the most active volcanoes in El Salvador, San Miguel is surrounded by important population nuclei and infrastructures. We used existing historical records of past eruptive activity, available geological knowledge and monitoring data gathered over the past sixteen years to conduct the first comprehensive, long-term hazard assessment of this volcano, aimed at helping to reduce the potential risk it poses. We applied probabilistic methods (QVAST and HASSET) specifically designed for volcanic hazard assessment to conduct two hazard analyses, one with a forecasting time window of two years using information on volcanic activity over the past 430years (historical period), and another with a forecasting window of six months, with information from the past 16years (monitoring period). In both cases we used the same susceptibility map constructed using the most relevant structural elements, which indicates the spatial probabilities of hosting a new vent on San Miguel volcano. Then, we calculated the most likely eruptive scenarios for each analysis and their corresponding forecasting windows, which revealed that the most hazardous areas correspond to Conacastal canton and hamlets of San Jorge, San Miguel and San Rafael Oriente – all lie within 5km of the central crater on the northern and southern flanks. This methodology is easy to update, and results can be improved by incorporating new information. This long-term hazard assessment is a significant contribution that will enable local authorities to implement more rational territorial planning and to design better emergency plans for coping with future volcanic crises.

The First Person Book of Terminal Addiction: William Burroughs’s Junky

The subject of this article is William Burroughs’s first work, Junky ([1953] 2003. London: Penguin). In particular, the relationship within it between experience and representation, text and biography, author and narrator are discussed, as are questions of genre and relevant structural elements. Of particular interest is the construction of the narrator, William Lee, in relation to the author, and as a figure manifesting Burroughs’s subcultural journey into addiction, and the meanings it takes in the text. Through Lee’s narrative, but also through the unavoidable reading of this text through the prism of Burroughs’s later subcultural fame, the real and fictional events depicted in Junky, and the mode of their representation, constitute a comment on Burroughs’s lifelong literary concerns and artistic outlook.

Specificity and mechanism of mandelamide hydrolase catalysis

The best-studied amidase signature (AS) enzyme is probably fatty acid amide hydrolase (FAAH). Closely related to FAAH is mandelamide hydrolase (MAH), whose substrate specificity and mechanism of catalysis are described in this paper. First, we developed a convenient chromogenic substrate, 4-nitrophenylacetamide, for MAH. The lack of reactivity of MAH with the corresponding ethyl ester confirmed the very limited size of the MAH leaving group site. The reactivity of MAH with 4-nitrophenyl acetate and methyl 4-nitrophenyl carbonate, therefore, suggested formation of an “inverse” acyl-enzyme where the small acyl-group occupies the normal leaving group site. We have interpreted the specificity of MAH for phenylacetamide substrates and small leaving groups in terms of its active site structure, using a homology model based on a FAAH crystal structure. The relevant structural elements were compared with those of FAAH. Phenylmethylboronic acid is a potent inhibitor of MAH (Ki = 27 nM), presumably because it forms a transition state analogue structure with the enzyme. O-Acyl hydroxamates were not irreversible inactivators of MAH but some were found to be transient inhibitors.

Arylthiosemicarbazones as antileishmanial agents

Based on a screening process, we targeted substituted thiosemicarbazone as potential antileishmanial agents. Our objective was to identify the key structural elements contributing to the anti-parasite activity that might be used for development of effective drugs. A series of 32 compounds was synthesized and their efficacy was evaluated against the clinically relevant intracellular amastigotes of Leishmania donovani. From these, 22 compounds showed EC50 values below 10 μM with the most active derivative (compound 14) showing an EC50 of 0.8 μM with very low toxicity on two different mammalian cell lines. The most relevant structural elements required for higher activity indicate that the presence of a fused bicyclic aromatic ring such as a naphthalene bearing an alkyl or an alkoxy group substituent are prerequisites. Owing to the easy synthesis, high activity and low toxicity, the most active compounds could be considered as a lead for further development.

Synthesis of alanyl nucleobase amino acids and their incorporation into proteins

Proteins which bind to nucleic acids and regulate their structure and functions are numerous and exceptionally important. Such proteins employ a variety of strategies for recognition of the relevant structural elements in their nucleic acid substrates, some of which have been shown to involve rather subtle interactions which might have been difficult to design from first principles. In the present study, we have explored the preparation of proteins containing unnatural amino acids having nucleobase side chains. In principle, the introduction of multiple nucleobase amino acids into the nucleic acid binding domain of a protein should enable these modified proteins to interact with their nucleic acid substrates using Watson-Crick and other base pairing interactions. We describe the synthesis of five alanyl nucleobase amino acids protected in a fashion which enabled their attachment to a suppressor tRNA, and their incorporation into each of two proteins with acceptable efficiencies. The nucleobases studied included cytosine, uracil, thymine, adenine and guanine, i.e. the major nucleobase constituents of DNA and RNA. Dihydrofolate reductase was chosen as one model protein to enable direct comparison of the facility of incorporation of the nucleobase amino acids with numerous other unnatural amino acids studied previously. The Klenow fragment of DNA polymerase I was chosen as a representative DNA binding protein whose mode of action has been studied in detail.

Integrated non-destructive assessment of relevant structural elements of an Italian heritage site: the Carthusian monastery of Trisulti

The analysis of historical structures in need of preservation and restoration interventions is a very complex task due to the large uncertainties in the characterization of structural properties and detailing in view of the structural response. Moreover, the predictive performance of numerical analyses and simulations depend on the availability of information about the constructional properties of the architectural complex, crack patterns and active degradation phenomena. In particular, local changes in material properties or damage due to past events (such as earthquakes) can affect individual structural elements. They can be hardly detected as a result of the maintenance interventions carried out over the centuries and the possibility to carry out limited or even no destructive investigations due to the historical relevance of the structure. Thus, non-destructive investigations play a fundamental role in the assessment of historical structures minimizing, at the same time, the invasiveness of interventions. The present paper deals with an explanatory case study concerning the structural investigations carried out in view of the seismic assessment of an Italian historical monument, the Carthusian monastery of Trisulti in Collepardo, erected in 1204 under Pope Innocenzo HI. The relevance of the case study is due to the application, in combination, of different NDT methods, such as sonic tests, and active and passive infrared thermography, in order to characterize relevant masonry elements. Moreover, an advanced system for the in-situ nondestructive vibration-based estimation of the tensile loads in ancient tie-rods is described and the main results obtained from its application for the characterization of the tie-rods of the cloister are presented.

A hydrotectonic model of a geothermal reservoir – A study in Lahendong, Indonesia

In this study tectonic structural features and their hydraulic characteristics of fault zones were integrated into a consistent hydrotectonic model of the Lahendong geothermal reservoir, Indonesia. Moreover, these elements were analysed with respect to their relevance for the operation of the geothermal power plant at initial conditions, i.e. before the start of operation. The complex tectonic setting with volcanic activity provides evidence for relevant structural and hydrogeological elements, such as fault zones, surface spring discharge and joints at different spatial scales. The study area is highly variable with respect to hydraulic properties and chemical composition of the fluids. It consists of two types of fluids. Acid brine water with a pH of around 3 and an electrical conductivity ranging between 4620μS/cm and 9700μS/cm is characteristic for the reservoir in the North with temperatures up to 274°C. A moderate pH between 4 and 7, an electrical conductivity in the range of 400–1730μS/cm and temperatures of up to 340°C characterise the southern study area. The Lahendong geothermal field is subdivided into two sub-reservoirs. Faults are less permeable perpendicular to the strike of the faults than parallel to the strike. The characteristics of the complex reservoir system could be explained by the combination of hydrotectonics and hydrogeological parameters. Understanding the permeability distribution along fault zones is crucial to investigate subsurface fluid pathways as well as to sustainably use the reservoir. A compartmentalisation of the reservoir was derived from a stress field analysis of the tectonic elements and from hydrogeological observations. The information on underground fluid flow is essential to understand the subsurface flow of geothermal fluids. Here, the permeability of structures is identified as the limiting factor.

Antarease-like Zn-metalloproteases are ubiquitous in the venom of different scorpion genera

BackgroundThe venoms of several scorpion species have long been associated with pancreatitis in animal models and humans. Antarease, a Zn-metalloprotease from Tityus serrulatus, is able to penetrate intact pancreatic tissue and disrupts the normal vesicular traffic necessary for secretion, so it could play a relevant role in the onset of acute pancreatitis. MethodsThe cDNA libraries from five different scorpion species were screened for antarease homologs with specific primers. The amplified PCR products were cloned and sequenced. A structural model was constructed to assess the functionality of the putative metalloproteases. A phylogenetic analysis was performed to identify clustering patterns of these venom components. ResultsAntarease-like sequences were amplified from all the screened cDNA libraries. The complete sequence of the antarease from T. serrulatus was obtained. The structural model of the putative antarease from Tityus trivittatus shows that it may adopt a catalytically active conformation, sharing relevant structural elements with previously reported metalloproteases of the ADAM family. The phylogenetic analysis reveals that the reported sequences cluster in groups that correlate with the geographical localization of the respective species. ConclusionsAntareases are ubiquitous to a broad range of scorpion species, where they could be catalytically active enzymes. These molecules can be used to describe the evolution of scorpion venoms under different ecogeographic constrains. General significanceFor the first time the complete sequence of the antareases is reported. It is demonstrated that antareases are common in the venom of different scorpion species. They are now proposed as targets for antivenom therapies.

Qualitative Order of Magnitude Energy-Flow-Based Failure Modes and Effects Analysis

This paper presents a structured power and energy-flow-based qualitative modelling approach that is applicable to a variety of system types including electrical and fluid flow. The modelling is split into two parts. Power flow is a global phenomenon and is therefore naturally represented and analysed by a network comprised of the relevant structural elements from the components of a system. The power flow analysis is a platform for higher-level behaviour prediction of energy related aspects using local component behaviour models to capture a state-based representation with a global time. The primary application is Failure Modes and Effects Analysis (FMEA) and a form of exaggeration reasoning is used, combined with an order of magnitude representation to derive the worst case failure modes. The novel aspects of the work are an order of magnitude(OM) qualitative network analyser to represent any power domain and topology, including multiple power sources, a feature that was not required for earlier specialised electrical versions of the approach. Secondly, the representation of generalised energy related behaviour as state-based local models is presented as a modelling strategy that can be more vivid and intuitive for a range of topologically complex applications than qualitative equation-based representations.The two-level modelling strategy allows the broad system behaviour coverage of qualitative simulation to be exploited for the FMEA task, while limiting the difficulties of qualitative ambiguity explanation that can arise from abstracted numerical models. We have used the method to support an automated FMEA system with examples of an aircraft fuel system and domestic a heating system discussed in this paper.

Resistance and Response of Steel and Steel–Concrete Composite Structures in Progressive Collapse Assessment

Within this article particularities concerning the handling of material characteristics of steel-concrete composite for progressive collapse assessment are discussed. How to influence the redundancy of the global structure not only by high material strength but also by highly ductile material behaviour is highlighted. Beside the material characteristics strength and ductility further important properties under the aspect of robustness, like over-strength effects, strain rate sensitivity and absorption capacity are within the scope of the paper. For ultimate limit state and service limit state analysis under basic design conditions the proof of all relevant structural elements as separate members is state-of-the-art in most of the codes and standards and is in line with the safety concept. So, most practical engineers are only familiar with considering basic design criteria for planning. Going beyond the “normal loading conditions” additional considerations are necessary to ensure structural safety for abnormal loading and for mitigating progressive failure when local damage occurs. Therefore it is fundamental for the structural engineer to be aware of modelling the actual structural response in a correct manner. Besides the knowledge of the modelling technique itself, information about the actual material behaviour is of high importance. But in nearly all current codes only nominal material models are available. So it is hardly possible for the practical engineer to get expected material properties of the relevant material characteristic as input for progressive collapse assessment. Within this article detailed information about the actual behaviour of steel-concrete composite will be provided.

Influence of Microstructure on Damage in Advanced High Strength Steels

AHSS (Advanced High Strength Steels) combine high strength and good ductility. Their outstanding forming and work-hardening behavior predestines these steels for fabrication of strength relevant structural elements and automobile body parts. To characterize a material, not only tensile, but also hole-expansion and bending behavior are important and help predict the stretch-flange-formability. In this study, detailed analyses of the correlation between these three tests and the damage mechanisms during forming have been performed for selected steels. The results show that for AHSS one should differentiate between “local” and “global” failure. Furthermore, not only are certain materials more sensitive to local or global damage, but also various testing methods tend to provoke either local or global damage. Tensile testing provokes global failure whereas hole-expansion tends to induce local failure. A specimen fails during bending with a mixture of local and global modes. These failure modes are strongly attributed to the microstructure. DP-steels yield high elongation during tensile testing and poorer hole-expansion values. High-resolution EBSD has revealed that the microstructure of DP-steels is sensitive to localized damage, which is compensated by work-hardening around damaged regions and thus shifts the loading to un-hardened regions. This makes DP-microstructures well-suited to tensile loading but sensitive to hole-expansion. CP-steels of comparable strength show poorer tensile elongation and higher hole-expansion ratios due to a microstructure which is not sensitive to localized failure (but has limited capacity for work-hardening). The failure mode in TRIP-steels exhibits a similar character as in DP-steels, but only after the martensitic transformation of retained austenite.

Sparse geologic dictionaries for subsurface flow model calibration: Part I. Inversion formulation

Inference of heterogeneous rock properties from low-resolution dynamic flow measurements often leads to underdetermined nonlinear inverse problems that can have many non-unique solutions. The problem is usually regularized by reducing the number of unknown parameters and/or incorporating direct or indirect prior information. In subsurface flow modeling, structural connectivity in hydraulic properties plays a critical role in determining local and global flow and displacement processes. When reliable prior information about the structural connectivity of a formation is available it can be used to discourage implausible inversion solutions. In this two-part paper, we introduce a geologically-inspired conceptual framework, geologic dictionaries, for reconstructing complex subsurface physical properties from the flow data. We evaluate the performance of our method under both reliable and highly uncertain prior knowledge and measurements. In Part I, we present inversion with sparse geologic dictionaries, learned from prior models, for estimation of complex heterogeneous subsurface hydraulic properties. We show how learning methods can be adapted to build, from a prior training library, specialized sparse geologic dictionaries that contain relevant structural elements (words) for constructing the solution of subsurface flow inverse problems. The key property of the constructed geologic dictionaries that we invoke during flow data integration is its “sparsity”; that is, we require that only a small subset of geologic dictionary elements be sufficient for accurately approximating any prior model realizations in the training library, and hence the model calibration solution. Using the sparsity property of the geologic dictionary, we formulate and solve the nonlinear model calibration as a feature estimation problem. To construct a solution, we adopt an iteratively reweighted least-squares (IRLS) algorithm to identify the important dictionary elements by minimizing a sparsity-regularized data misfit objective function. We illustrate the flexibility and effectiveness of the proposed method by applying it to a series of numerical experiments in multiphase flow systems and compare it with parameterization by truncated singular vectors.

Quantitative Prediction of Cell Wall Polysaccharide Composition in Grape (Vitis vinifera L.) and Apple (Malus domestica) Skins from Acid Hydrolysis Monosaccharide Profiles

On the basis of monosaccharide analysis after acid hydrolysis of fruit skin samples of three wine grape cultivars, Vitis vinifera L. Cabernet Sauvignon, Merlot, and Shiraz, and of two types of apple, Malus domestica Red Delicious and Golden Delicious, an iterative calculation method is reported for the quantitative allocation of plant cell wall monomers into relevant structural polysaccharide elements. By this method the relative molar distribution (mol %) of the different polysaccharides in the red wine grape skins was estimated as 57-62 mol % homogalacturonan, 6.0-14 mol % cellulose, 10-11 mol % xyloglucan, 7 mol % arabinan, 4.5-5.0 mol % rhamnogalacturonan I, 3.5-4.0 mol % rhamnogalacturonan II, 3 mol % arabinogalactan, and 0.5-1.0 mol % mannans; the ranges indicate minor variations in the skin composition of the three different cultivars. These cell wall polysaccharides made up approximately 43-47% by weight of the skins (dry matter), the rest mainly being lignin. The predicted relative molar levels of the polysaccharide elements in the apple skins, which made up approximately 49-64% by weight of the skins (dry matter), appeared to be similar to those of the grape skins. The apple skins were estimated to be relatively richer than grape skins in arabinan, total levels 10-13 mol %, and relatively lower in mannan content, total levels </=0.3 mol %. The data also demonstrate the superiority of trifluoroacetic acid to hydrochloric acid for hydrolysis of plant cell wall material to monosaccharides, notably with respect to the galacturonic acid levels and, in turn, in relation to predicting the relative contents of structural pectin elements in the plant cell wall substrates.