Modelling spatial heterogeneity and nonstationarity in artifact-rich landscapes

In this paper we consider a crucial issue for survey archaeology: how we identify and make sense of the heterogeneous and often inter-dependent behaviours and processes responsible for apparent archaeological patterns across the landscape. We apply two spatial statistical tools, kriging and geographically weighted regression, to develop a model that addresses the spatial heterogeneity and spatial nonstationarity present in the pottery distributions identified by our intensive survey of the Greek island of Antikythera. Our modelling results highlight a clear spatial structure underlying different scales of pottery density as well as locally varying relationships between pottery densities and several environmental variables. This allows us to develop further testable hypotheses about long-term settlement and land-use patterns on Antikythera, including more explicit models of community organisation, and of the relationship between the island’s geomorphological structure and its history of past human activity

Collecting Biomarkers Using Trained Interviewers. Lessons Learned from a Pilot Study

This paper reports the design and outcomes of a pilot study for the UK Household Longitudinal Study (UKHLS), Understanding Society, to develop and test the feasibility of collection of biomarkers by trained non-clinical interviewers. Feasibility tests performance of procedures, that they are technically satisfactory and reasonable in relation to alternatives. The dimensions reported are recruitment and training of interviewers, completeness, acceptability and time required for data collection, and quality of the biological samples. Some comparisons are made with measures conducted by nurses in wave 2 of the UK Household Longitudinal Study, Understanding Society. Biomeasures included anthropometrics, blood pressure, grip strength and the collection of saliva and dried blood spots. We implemented measurement protocols, introduced training and certification of interviewers, who then collected data from 92 participants. The study produced information about duration of collection, participation and quality of blood and saliva samples. The pilot study informs the design decisions about the biosocial component of Understanding Societ

Income-based inequalities in hypertension and in undiagnosed hypertension: analysis of Health Survey for England data

Objective: To quantify income-based inequalities in hypertension and in undiagnosed hypertension. Methods: We used nationally representative data from 28 002 adults (aged 16 years and older) living in private households who participated in the cross-sectional Health Survey for England 2011–2016. Using bivariate probit regression modelling, we jointly modelled hypertension and self-reported previous diagnosis of hypertension by a doctor or nurse. We then used the model estimates to quantify inequalities in undiagnosed hypertension. Inequalities, using household income tertiles as an indicator of socioeconomic status, were quantified using average marginal effects (AMEs) after adjustment for confounding variables. Results: Overall, 32% of men and 27% of women had survey-defined hypertension (measured blood pressure ≥140/90 mmHg and/or currently using medicine to treat high blood pressure). Higher proportions (38% of men and 32% of women) either self-reported previous diagnosis or had survey-defined hypertension. Of these, 65% of men and 70% of women had diagnosed hypertension. Among all adults, participants in low-income versus high-income households had a higher probability of being hypertensive [AMEs: men 2.1%; 95% confidence interval (CI): −0.2, 4.4%; women 3.7%; 95% CI: 1.8, 5.5%] and of being diagnosed as hypertensive (AMEs: men 2.0%; 95% CI: 0.4, 3.7%; women 2.5%; 95% CI: 1.1, 3.9%). Among those classed as hypertensive, men in low-income households had a marginally lower probability of being undiagnosed than men in high-income households (AME: −5.2%; 95% CI: −10.5, 0.1%), whereas no difference was found among women. Conclusion: Our findings suggest that income-based inequalities in hypertension coexist with equity in undiagnosed hypertension

Roman pottery from an intensive survey of antikythera, Greece

Recent intensive survey over the entire extent of the small island of Antikythera has recovered an episodic sequence of human activity spanning some 7,000 years, including a Roman pottery assemblage that documents a range of important patterns with respect to land use, demography and on-island consumption. This paper addresses the typological and functional aspects of this assemblage in detail, and also discusses Roman period Antikythera's range of off-island contacts and affiliations

Vegetation recolonisation of abandoned agricultural terraces on Antikythera, Greece

Antikythera is a small, relatively remote Mediterranean island, lying 35 km north-west of Crete, and its few contemporary inhabitants live mainly in the small village at the only port. However, an extensive network of terraces across the island bears witness to the past importance of farming on the island, although the intensity of use of these cultivated plots has changed according to fluctuating population levels. Most recently, the rural population and intensity of cultivation have dramatically declined. Our aim is to understand the recolonisation process of agricultural land by plants after terraces are no longer used for the cultivation of crops. The results demonstrate a relatively quick pace of vegetative recolonisation, with abandoned farm land covered by dense scrub within 20 to 60 years. The archaeological implications are that, following even relatively short periods of abandonment, the landscape would have required arduous reinvestment in the removal of scrub growth, as well as the repair and construction of stone terraces, to allow cultivation once again

From fabrics to island connections: Macroscopic and microscopic approaches to the prehistoric pottery of Antikythera

An intensive archaeological survey covering the entire extent of the island of Antikythera has recently revealed a sequence of prehistoric activity spanning the later Neolithic to Late Bronze Age, with cultural affiliations that variously link its prehistoric communities with their neighbours to the north, south and east. Here we present and discuss the results of a programme of both macroscopic and petrographie study of the prehistoric ceramics from Antikythera that defines a considerably varied group of fabrics and explores their implications with regard to regional potting traditions, on-island production versus imports, and changing patterns of human activity on the island through time. / Abstract in Greek: Μια εντατική επιφανειακή έρευνα που κάλυψε το σύνολο της έκτασης των Aντικυθήρων αποκάλυψε πρόσφατα μια ακολουθία προïστορικής δραστηριότητας που χρονολογείται από την προχωρημένη Nεολιθική μέχρι την ´Yστερη Eποχή του Xαλκού, και αντανακλά ποικίλες πολιτιστικές σχέσεις των προïστορικών κοινοτήτων του νησιού με γειτονικές περιοχές στα βόρεια, νότια καν ανατολικά. Eσώ παρουσιάςουμε και (τυςητάμε τα αποτελέσματα ενός προγράμματος μακροσκοπικής και πετρογραφικής μελέτης της προïστορικής κεραμικής από τα Aντικύθηρα, που προσδιορίςει μια σημαντική ποικνλία κεραμικών υλών και διερευνά τη σημασία τους σε σχέση με τις τοπικές παραδόσενς κεραμικής στην ευρύτερη περιοχή του Aιγαίου, την αντιδιαςτολή εγχώρνας παραγωγής καν ενσαγωγών, και τις δναχρονικές μεταβολές στο χαρακτήρα και την ένταση της ανθρώπινης δραστηριότητας στο νησί

Nested recursions with ceiling function solutions

Consider a nested, non-homogeneous recursion R(n) defined by R(n) = \sum_{i=1}^k R(n-s_i-\sum_{j=1}^{p_i} R(n-a_ij)) + nu, with c initial conditions R(1) = xi_1 > 0,R(2)=xi_2 > 0, ..., R(c)=xi_c > 0, where the parameters are integers satisfying k > 0, p_i > 0 and a_ij > 0. We develop an algorithm to answer the following question: for an arbitrary rational number r/q, is there any set of values for k, p_i, s_i, a_ij and nu such that the ceiling function ceiling{rn/q} is the unique solution generated by R(n) with appropriate initial conditions? We apply this algorithm to explore those ceiling functions that appear as solutions to R(n). The pattern that emerges from this empirical investigation leads us to the following general result: every ceiling function of the form ceiling{n/q}$ is the solution of infinitely many such recursions. Further, the empirical evidence suggests that the converse conjecture is true: if ceiling{rn/q} is the solution generated by any recursion R(n) of the form above, then r=1. We also use our ceiling function methodology to derive the first known connection between the recursion R(n) and a natural generalization of Conway's recursion.Comment: Published in Journal of Difference Equations and Applications, 2010. 11 pages, 1 tabl