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This paper investigates the distributions of triangle counts per vertex and edge, as a means for network description, analysis, model building, and other tasks. The main interest is in estimating these distributions through sampling, especially for large networks. A novel sampling method tailored for the estimation analysis is proposed, with three sampling designs motivated by several network access scenarios. An estimation method based on inversion and an asymptotic method are developed to recover the entire distribution. A single method to estimate the distribution using multiple samples is also considered. Algorithms are presented to sample the network under the various access scenarios. Finally, the estimation methods on synthetic and real-world networks are evaluated in a data study.

The introduction of mammal predators has been a major cause of species extinctions on oceanic islands. Eradication is only possible or cost-effective at early stages of invasion, before introduced species become abundant and widespread. Although prevention, early detection and rapid response are the best management strategies, most oceanic islands lack systems for detecting, responding to and monitoring introduced species. Wildlife managers require reliable information on introduced species to guide, assess and adjust management actions. Thus, a large-scale and long-term monitoring programme is needed to evaluate the management of introduced species and the protection of native wildlife. Here, we evaluate camera trapping as a survey technique for detecting and monitoring introduced small and medium-sized terrestrial mammals on an oceanic island, Terceira (Azores). Producing an inventory of introduced mammals on this island required a sampling effort of 465 camera-trap days and cost EUR 2,133. We estimated abundance and population trends by using photographic capture rates as a population index. We also used presence/absence data from camera-trap surveys to calculate detection probability, estimated occupancy rate and the sampling effort needed to determine species absence. Although camera trapping requires large initial funding, this is offset by the relatively low effort for fieldwork. Our findings demonstrate that camera trapping is an efficient survey technique for detecting and monitoring introduced species on oceanic islands. We conclude by proposing guidelines for designing monitoring programmes for introduced species., LLL was supported by a grant from the Fundação para a Ciência e Tecnologia—FCT (SFRH/BD/115022/2016).

Editorial.

Traditionally, single realizations of the turbulent state have been the object of study in shear flow turbulence. When a statistical quantity was needed it was obtained from a spatial, temporal or ensemble average of sample realizations of the turbulence. However, there are important advantages to studying the dynamics of the statistical state (the SSD) directly. In highly chaotic systems statistical quantities are often the most useful and the advantage of obtaining these statistics directly from a state variable is obvious. Moreover, quantities such as the probability density function (pdf) are often difficult to obtain accurately by sampling state trajectories even if the pdf is stationary. In the event that the pdf is time dependent, solving directly for the pdf as a state variable is the only alternative. However, perhaps the greatest advantage of the SSD approach is conceptual: adopting this perspective reveals directly the essential cooperative mechanisms among the disparate spatial and temporal scales that underly the turbulent state. While these cooperative mechanisms have distinct manifestation in the dynamics of realizations of turbulence both these cooperative mechanisms and the phenomena associated with them are not amenable to analysis directly through study of realizations as they are through the study of the associated SSD. In this review a selection of example problems in the turbulence of planetary and laboratory flows is examined using recently developed SSD analysis methods in order to illustrate the utility of this approach to the study of turbulence in shear flow.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. In this article, based on four decades of experience of using samples in diverse ways in experimental, particularly electroacoustic compositions, the author investigates the world of what he calls ‘sample-based sound-based music’ and suggests that there is a relative lack of scholarship in this important area. The article’s contextual sections focus on briefly delineating this world of sonic creativity and placing it within today’s sampling culture as well as dealing with two political aspects of sampling, a musician’s attitude towards the reuse of sonic materials and the legality of sampled sounds, including musical passages, in the discussion of which current legislation related to sampling is challenged. Following this, a number of categories are presented in terms of the types of sampling material that is being used as well as how sample-based works are presented. The subsequent section is perhaps the most poignant in the article, namely the opening up of this form of innovative composition from a more traditional ‘artist creates work’ mode of operation to a more collaborative one which is essentially already part of most other forms of sampling culture. The objective here is to suggest that such collaborative approaches will enable sample-based sound-based music to become part of the lives of a much broader group than those currently involved with it.

Radiocarbon (14C) activity in groundwater can be used to determine subsurface residence time up to ∼40 kyr, providing crucial information on dynamic properties of groundwater and on paleoclimate. However, commonly applied sampling methods for dissolved inorganic carbon (DIC-14C) are prone to low level of modern atmospheric contamination, resulting in underestimation of groundwater ages that cluster around 30–40 kyr. We extract CO2gas from groundwater using a device originally developed for studies of noble gas radionuclides. Carbon is collected in the gas phase, eliminating the possibility of fostering microbial activities and aqueous chemical reactions during sample storage. This method collects CO2-14C and radiokrypton (81Kr and85Kr) samples simultaneously. The presence of any shorter-lived85Kr is used to evaluate the degree of atmospheric contamination during sampling or mixing of young groundwater. Most groundwater samples showed lower CO2-14C activities than those of DIC-14C, presumably due to the absence of atmospheric contamination. Samples with81Kr age exceeding 150 kyr have no detectable CO2-14C except where mixing sources of young groundwater is suspected. These field data serve as confirmations for the reliability of the newly presented sample collection and CO2-14C method, and for the outstanding roles of radiokrypton isotopes in characterizing old groundwater.

I conducted the list experiment with a nationally representative sample of 2,000 Kenyans. I designed the survey items and implemented them with the survey firm, Synovate, as part of their quarterly Social, Political, Economic, and Cultural Survey (SPEC). The surveywas conducted in Kiswahili by trained enumerators. Sampling points were selected through multistage cluster sampling. Using the 2009 census administrative boundaries, 55 of 69 districts were selected in the first stage. Sampling points—defined as the sub-location, the smallest administrative unit for which census data are available—were then selected using probability-proportion-to-size sampling, using data from the 2009 census. After arriving at the selected sampling points, interviewers selected respondents in the following manner. First, interviewers identified a landmark at the sampling site (church, school, shop, and so on). Starting from the landmark, the interviewers used the summation method to select the first household to be sampled. This involves summing the last two digits of the date to determine the first household to be sampled. If the interviews took place on the 27th, the interviewers would have selected the 9th household on the left from the landmark. After the first household, the interviewers sampled every fourth household on the left. If an interview attempt was unsuccessful, the interviewers continued to the immediate next household. After selecting a household, interviewers enumerated all occupants of the household over 18 years of age and used the serial number on the questionnaire to select the respondent. If the respondent was not home, the interviewer would return to the household three times to find the respondent. If the respondent was not available after the three attempts, another member of the household was substituted in the following manner: on even dates, the person above the original respondent on the household list was chosen and on odd dates the person below was selected.

1 Boltzmann generation of Random Combinatorial Structures Our aim is to describe a general purpose sampling algorithm for a given class of graphs. Notation: we denote by A any class of graphs, and write A = ⋃ n≥0An, where An consists of all elements of A that have n vertices. We will always assume that graphs are welllabeled, meaning that each graph in An has labels from the set [n]. If a graph G is not well-labeled, then we write ρ(G) for the graph obtained by relabeling G canonically, hence ρ(G) is well-labeled. Remark 1.1. A canonical relabeling is such that it preserves the order of the labels. For every n ≥ 0, let us set an = |An|. We will write

Statistical designs, sample surveys and evaluation designs are fundamental tools for solving queries related to population parameters and the effects of public programs and policies. This book explores the concepts of effective sampling and evaluation techniques in a cohesive and concise manner. Sampling design techniques, including simple random sampling, stratified sampling, systematic sampling and cluster sampling, are presented in detail. These techniques play a vital role when choosing an appropriate sample survey design. The concepts of multistage design, non-sampling errors and evaluation techniques including before-after design, one-time treatment and control design are discussed extensively. The book focuses on different methods of estimation, including multiple regression analysis and logistic regression. It covers the issue of bias in a design, the source of such bias and ways to overcome it. Clear guidelines with remedial measures are outlined to facilitate choosing a suitable sampling design.

SUMMARYMultiple cases of atypical scrapie in the same holding and co-existence with classical scrapie have been reported in Great Britain. A two-stage simulation tool was developed by combining a sampling algorithm and a hierarchical Bayesian model to simulate the number of positive cases of atypical scrapie from: (i) random sampling and (ii) using the actual sampled population in Great Britain, being the output probability of detection of flocks with one and more cases. Cluster analysis was conducted to assess the level of geographical over- and under-sampling over the years. The probability of detecting at least two cases of atypical scrapie in the same holding is much lower in simulated random data than in simulated actual data for all scenarios. Sampling bias in the selection of sheep for testing led to multiple sampling from fewer but larger holdings, Scotland, and areas of Wales were under-sampled and the South-West and East of England oversampled. The pattern of atypical scrapie cases observed is unlikely to be explained by a multi-case event epidemiologically linked. The co-existence of classical and atypical scrapie is a rare event with 19 holdings detected in GB and does not suggest an epidemiological link between the two types of disease.

The ability to directly record human face-to-face interactions increasingly enables the development of detailed data-driven models for the spread of directly transmitted infectious diseases at the scale of individuals. Complete coverage of the contacts occurring in a population is however generally unattainable, due for instance to limited participation rates or experimental constraints in spatial coverage. Here, we study the impact of spatially constrained sampling on our ability to estimate the epidemic risk in a population using such detailed data-driven models. The epidemic risk is quantified by the epidemic threshold of the susceptible-infectious-recovered-susceptible model for the propagation of communicable diseases, i.e. the critical value of disease transmissibility above which the disease turns endemic. We verify for both synthetic and empirical data of human interactions that the use of incomplete data sets due to spatial sampling leads to the underestimation of the epidemic risk. The bias is however smaller than the one obtained by uniformly sampling the same fraction of contacts: it depends nonlinearly on the fraction of contacts that are recorded and becomes negligible if this fraction is large enough. Moreover, it depends on the interplay between the timescales of population and spreading dynamics., 21 pages, 7 figures

SUMMARYEnvironmental samples are a cost-saving and easy-to-use approach to diagnose paratuberculosis at the herd level. Detailed knowledge concerning its uncertainties in herds with a low prevalence of Mycobacterium avium spp. paratuberculosis (MAP) is required to design sampling strategies in control programmes. This study aimed to calculate a threshold level of the apparent within-herd prevalence (WHPapp) as determined by individual mycobacterial cultivation (faecal culture; FC) of all cows thus allowing the detection of a herd as MAP-positive at a certain probability level (Pd). Out of 200 environmental samples taken twice from five predefined locations in a barn, 25 were positive by FC and 60 were positive by a quantitative real-time PCR method (qPCR). A logistic regression model was used to calculate the WHPapp threshold of detection. For 50% Pd, a WHPapp threshold of 2·9% was calculated for the combination of three samples (milking area, main cow alleyways, holding pen) tested simultaneously both by FC and qPCR. The threshold increased to 6·2% for 90% Pd. Repeated environmental sampling did not reduce the WHPapp threshold. Depending on the particular needs for prevalence estimation or in control programmes (single or repeated sampling) the provided WHPapp thresholds at different Pd will enable decisions to be made about various sampling strategies.