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The thymus undergoes a critical period of growth and development early in gestation and, by mid-gestation, immature thymocytes are subject to positive and negative selection. Exposure to undernutrition during these periods may permanently affect phenotype. We measured thymulin concentrations, as a proxy for thymic size and function, in children (n = 290; aged 9–13 years) born to participants in a cluster-randomized trial of maternal vitamin A or β-carotene supplementation in rural Nepal (1994–1997). The geometric mean (95% confidence interval) thymulin concentration was 1.37 ng/ml (1.27, 1.47). A multivariate model of early-life exposures revealed a positive association with gestational age at delivery (β = 0.02; P = 0.05) and higher concentrations among children born to β-carotene-supplemented mothers (β = 0.19; P < 0.05). At ∼9–12 years of age, thymulin was positively associated with all anthropometric measures, with height retained in our multivariate model (β = 0.02; P < 0.001). There was significant seasonal variation: concentrations tended to be lower pre-monsoon (β = −0.13; P = 0.15), during the monsoon (β = −0.22; P = 0.04), and pre-harvest (β = −0.34; P = 0.01), relative to the post-harvest season. All early-life associations, except supplementation, were mediated in part by nutritional status at follow-up. Our findings underscore the known sensitivity of the thymus to nutrition, including potentially lasting effects of early nutritional exposures. The relevance of these findings to later disease risk remains to be explored, particularly given the role of thymulin in the neuroendocrine regulation of inflammation.
The electrical reliability of multilayer high density interconnection printed circuit boards (HDI-PCBs) is mainly affected by the thermo-mechanical stability of stacked micro via interconnections. Here, a critical failure mode is the stress related crack between the electrolytically filled via and the target pad, commonly known as target pad separation. The junction includes two Cu-Cu-interfaces, one between the target Cu pad and the thin electroless Cu layer and the second between electroless Cu and electrolytic Cu. In this paper we will show that state-of-the-art electroless Cu plating processes are able to provide solid, completely recrystallized and highly reliable stacked via junctions. Defect free interfaces were achieved by using ionic Pd-activators and electroless Cu baths with a cyanide based stabilizer system. Cyanide free electroless Cu baths tend more to the formation of nanometer sized defects, discovered via Transmission Electron Microscopy (TEM). In this case a precise adjustment of single stabilizer components is mandatory to achieve defect free layers. The defects are hollow and were identified as “nano voids”. A critical density of these nano voids weakens the interface, predefines the crack path and reduces the overall reliability of the junction. A precise localization of the nano voids within the junction was enabled by detecting the Ni-containing electroless Cu layer via TEM-Ni mapping. Slower volume exchange of the electroless Cu solution within the blind micro via (BMV) substantially increases the nano void density. The ability of nano voids to migrate and coalesce at elevated temperatures was investigated as well.
Maternal systemic inflammation during pregnancy may restrict embryo−fetal growth, but the extent of this effect remains poorly established in undernourished populations. In a cohort of 653 maternal−newborn dyads participating in a multi-armed, micronutrient supplementation trial in southern Nepal, we investigated associations between maternal inflammation, assessed by serum α1-acid glycoprotein and C-reactive protein, in the first and third trimesters of pregnancy, and newborn weight, length and head and chest circumferences. Median (IQR) maternal concentrations in α1-acid glycoprotein and C-reactive protein in the first and third trimesters were 0.65 (0.53–0.76) and 0.40 (0.33–0.50) g/l, and 0.56 (0.25–1.54) and 1.07 (0.43–2.32) mg/l, respectively. α1-acid glycoprotein was inversely associated with birth size: weight, length, head circumference and chest circumference were lower by 116 g (P = 2.3 × 10−6), and 0.45 (P = 3.1 × 10−5), 0.18 (P = 0.0191) and 0.48 (P = 1.7 × 10−7) cm, respectively, per 50% increase in α1-acid glycoprotein averaged across both trimesters. Adjustment for maternal age, parity, gestational age, nutritional and socio-economic status and daily micronutrient supplementation failed to alter any association. Serum C-reactive protein concentration was largely unassociated with newborn size. In rural Nepal, birth size was inversely associated with low-grade, chronic inflammation during pregnancy as indicated by serum α1-acid glycoprotein.
In liberal economic thought, debating the “good society” was particularly prominent in the middle decades of the twentieth century, a period in which, as John Maynard Keynes (1883–1946) put it, people were “unusually expectant of a more fundamental diagnosis.” Good society here describes a normative horizon against which arguments are legitimized and toward which societies should strive. The term itself is mentioned rarely by economists. Mostly, they shared the notion that what is “good” cannot be defined in detail beyond the fact that it entails more than individual happiness and thus more than the hedonistic utilitarianism attached to the liberal tradition of the eighteenth and nineteenth centuries.
The origin of malnutrition in older age is multifactorial and risk factors may vary according to health and living situation. The present study aimed to identify setting-specific risk profiles of malnutrition in older adults and to investigate the association of the number of individual risk factors with malnutrition.
Data of four cross-sectional studies were harmonized and uniformly analysed. Malnutrition was defined as BMI < 20 kg/m2 and/or weight loss of >3 kg in the previous 3–6 months. Associations between factors of six domains (demographics, health, mental function, physical function, dietary intake-related problems, dietary behaviour), the number of individual risk factors and malnutrition were analysed using logistic regression.
Community (CD), geriatric day hospital (GDH), home care (HC), nursing home (NH).
CD older adults (n 1073), GDH patients (n 180), HC receivers (n 335) and NH residents (n 197), all ≥65 years.
Malnutrition prevalence was lower in CD (11 %) than in the other settings (16–19 %). In the CD sample, poor appetite, difficulties with eating, respiratory and gastrointestinal diseases were associated with malnutrition; in GDH patients, poor appetite and respiratory diseases; in HC receivers, younger age, poor appetite and nausea; and in NH residents, older age and mobility limitations. In all settings the likelihood of malnutrition increased with the number of potential individual risk factors.
The study indicates a varying relevance of certain risk factors of malnutrition in different settings. However, the relationship of the number of individual risk factors with malnutrition in all settings implies comprehensive approaches to identify persons at risk of malnutrition early.
Early development of the polychaetes Capitella sp. TF from Tampa, Florida and Capitella sp. TV from Tamiahua Lagoon, Veracruz was studied under laboratory conditions. Our observations indicate that hermaphrodites occur in Capitella sp. TF, but not in Capitella sp. TV. Length and volume of larvae and early juveniles were measured daily. Both species appear to have lecithotrophic development. Sizes and duration of the developmental stages varied widely, as in most known species of Capitella. Characteristic features of Capitella sp. TF include very small hermaphrodites with a distinct dorsal pigmentation pattern and characteristically shaped brood tubes with a centrally thickened region. Embryos forced to abandon the brood did not survive more than 3 days, and handling the brood produced alterations in timing. Ciliated metatrochophores from Capitella sp. TV survived inside the brood without the female for at least 14 days and some larvae hatched and died during settling. Some of these larvae were abnormal, with two rounded protuberances in the two ends. Mortality was high. Fungi and protozoans appeared in the dishes and probably partially induced the production of thicker mucus in the brood tubes, delay in metamorphosis, juvenile mortality, worm length and failure in coupling. Size and duration of the developmental stages were distinctly different from the other putative lecithotrophic species of the complex. These differences and other characteristics of each species discard the possibility that they belong to a previously described species. Our results are applicable to future ecological, morphological and molecular studies of each species, habitat and phylogenetics.
We documented the consequences of large-scale habitat loss on a community of Galápagos native bird species on San Cristóbal island, based on point counts conducted between 2010 and 2017. Surprisingly, despite considerable habitat change and a variety of other threats, the landbirds of San Cristóbal have fared much better than on the neighbouring islands Floreana or Santa Cruz. While two species went extinct very soon after human colonisation, the majority have adapted well to subsequent vegetation change and habitat loss. The endemic San Cristóbal Mockingbird Mimus melanotis is more widespread than previously thought and its population seems to be stable since the 1980s. We thus propose a change in IUCN classification from ‘Endangered’ to ‘Near threatened’. We present evidence gained by interviewing locals which suggests that a small population of the Least Vermilion Flycatcher Pyrocephalus dubius, classified as ‘Extinct’ by BirdLife International, may have persisted until very recently. Although extensive searches in 2018 and 2019 were unsuccessful, the possibility remains that a few birds may have survived in remote parts of the island. Further searches that involve the general public and other interested parties are therefore deemed necessary.
An important generalization of classical finite-state automata are multi-tape automata, which are used for recognizing relations of a particular type. The so-called regular relations (also refered to as ‘rational relations’) offer a natural way to formalize all kinds of translations and transformations, which makes multi-tape automata interesting for many practical applications and explains the general interest in this kind of device. A natural subclass are monoidal finite-state transducers, which can be defined as two-tape automata where the first tape reads strings. In this chapter we present the most important properties of monoidal multi-tape automata in general and monoidal finite-state transducers in particular. We show that the class of relations recognized by n-tape automata is closed under a number of useful relational operations like composition, Cartesian product, projection, inverse etc. We further present a procedure for deciding the functionality of classical finite-state transducers.
As a starting point we study finite-state automata, which represent the simplest devices for recognizing languages. The theory of finite-state automata has been described in numerous textbooks both from a computational and an algebraic point of view. Here we immediately look at the more general concept of a monoidal finite-state automaton, and the focus of this chapter is general constructions and results for finite-state automata over arbitrary monoids and monoidal languages. Refined pictures for the special (and more standard) cases where we only consider free monoids or Cartesian products of monoids will be given later.
In this chapter we present C(M) implementations of the main automata constructions. Our aim is to provide full descriptions of the implementations that are clear and easy to follow. In some cases the simplicity of the implementation is achieved at the expense of some inefficiency.
This chapter describes a special construction based on finite-state automata with important applications: the Aho–Corasick algorithm is used to efficiently find all occurrences of a finite set of strings (also called pattern set, or dictionary) in a given input string, called the ‘text’. Search is ‘online’, which means that the input text is neither fixed nor preprocessed in any way. This problem is a special instance of pattern matching in strings, and other automata constructions are used to solve other pattern matching tasks. From an automaton point of view, the Aho–Corasick algorithm comes in two variants. We first present the more efficient version where a classical deterministic finite-state automaton is built for text search. The disadvantage of this first construction is that the resulting automaton can become very large, in particular for large pattern alphabets. Afterwards we present the second version, where an automaton with additional transitions of a particular kind is built, yielding a much smaller device for text search.
Classical finite-state automata represent the most important class of monoidal finite-state automata. Since the underlying monoid is free, this class of automaton has several interesting specific features. We show that each classical finite-state automaton can be converted to an equivalent classical finite-state automaton where the transition relation is a function. This form of ‘deterministic’ automaton offers a very efficient recognition mechanism since each input word is consumed on at most one path. The fact that each classical finite-state automaton can be converted to a deterministic automaton can be used to show that the class of languages that can be recognized by a classical finite-state automaton is closed under intersections, complements, and set differences. The characterization of regular languages and deterministic finite-state automata in terms of the ‘Myhill–Nerode equivalence relation’ to be introduced in the chapter offers an algebraic view on these notions and leads to the concept of minimal deterministic automata.
In this chapter we explore deterministic finite-state transducers. Obviously, it only makes sense to ask for determinism if we restrict attention to transducers with a functional input-output behaviour. In this chapter we focus on transducers that are deterministic on the input tape (called sequential or subsquential transducers). We shall see that only a proper subset of all regular string functions can be represented by this kind of device and we describe a decision procedure for testing whether a functional transducer can be determinized. Further we present a subsequential transducer minimization procedure based on the Myhill–Nerode relation for string functions.
A common task arising in many contexts is rewriting parts of a given input string to another form. Subparts of the input that match specific conditions are replaced by other output parts. In this way, the complete input string is translated to a new output form. Due to the importance of text rewriting, many programming languages offer matching/rewriting operations for subexpressions of strings, also called replace rules. When using strictly regular relations and functions for representing replace rules, a cascade of replace rules can be composed into a single transducer. If the transducer is functional, an equivalent bimachine or (in some cases) a subsequential transducer can be built, thus achieving theoretically and practically optimal text processing speed. In this chapter we introduce basic constructions for building text rewriting transducers and bimachines from replace rules and provide implementations. A first simple version in general leads to an ambiguous form of text rewriting with several outputs. A second more sophisticated construction solves conflicts using the leftmost-longest match strategy and leads to functional devices.
A fundamental task in natural language processing is the efficient representation of lexica. From a computational viewpoint, lexica need to be represented in a way directly supporting fast access to entries, and minimizing space requirements. A standard method is to represent lexica as minimal deterministic (classical) finite-state automata. To reach such a representation it is of course possible to first build the trie of the lexicon and then to minimize this automaton afterwards. However, in general the intermediate trie is much larger than the resulting minimal automaton. Hence a much better strategy is to use a specialized algorithm to directly compute the minimal deterministic automaton in an incremental way. In this chapter we describe such a procedure.