Systematic Patterns Of Variation Research Articles

An Analysis of How Language Usage Show Systematic Pattern of Variation Based on Linguistics and Social Factors

This study aims to determine the pattern of systematic variation in language use based on social and linguistic factors seen from a pragmatic point of view. This type of research uses qualitative research methods. The data collection technique used in this study is a library research method that focuses on the study of various literature by analyzing the content in it. In addition, the data collection research used in this study was observation and interviews. The data analysis technique used is a content analysis technique. The research sample in this article is the people from Medan. Based on the results of the research that language can affect systematic variation based on social and linguistic factors. Based on pragmatic linguistic factors, language use can influence systematic variation due to several factors, such as habitual factors, environmental factors, and interest factors in certain language styles. While social factors can affect systematic variations in language use, especially occupational factors, because the work environment greatly determines how a person's language style in everyday life.This study aims to determine the pattern of systematic variation in language use based on social and linguistic factors seen from a pragmatic point of view. This type of research uses qualitative research methods. The data collection technique used in this study is a library research method that focuses on the study of various literature by analyzing the content in it. In addition, the data collection research used in this study was observation and interviews. The data analysis technique used is a content analysis technique. The research sample in this article is the people from Medan. Based on the results of the research that language can affect systematic variation based on social and linguistic factors. Based on pragmatic linguistic factors, language use can influence systematic variation due to several factors, such as habitual factors, environmental factors, and interest factors in certain language styles. While social factors can affect systematic variations in language use, especially occupational factors, because the work environment greatly determines how a person's language style in everyday life.

Depth-Dependent Diversity Patterns of Rocky Subtidal Macrobenthic Communities Along a Temperate Fjord in Northern Chilean Patagonia

Understanding the distribution of biodiversity along environmental gradients allows us to predict how communities respond to natural and anthropogenic impacts. In fjord ecosystems, the overlap of strong salinity and temperature gradients provides us with the opportunity to assess the spatial variation of biodiversity along abiotic environmental gradients. However, in Northern Chilean Patagonia (NCP), a unique and at the same time threatened fjord system, the variation of macrobenthic communities along abiotic environmental gradients is still poorly known. Here, we tested whether macrobenthic species diversity and community structure followed systematic patterns of variation according to the spatial variation in salinity and temperature in Comau Fjord, NCP. A spatially extensive nested sampling design was used to quantify the abundance of subtidal macrobenthic species along the fjord axis (fjord sections: head, middle, and mouth) and a depth gradient (0–21 m). The vertical structure of the water column was strongly stratified at the head of the fjord, characterized by a superficial (depth to ca. 5 m) low-salinity and relatively colder layer that shallowed and decayed toward the mouth of the fjord. The biotic variation followed, in part, this abiotic spatial pattern. Species richness peaked at high salinities (>27 psu) between 5 and 10 m in the head section and between 15 and 21 m in the middle and mouth sections. Diversity and evenness were also highest at these salinities and depth ranges in the head and middle sections, but at shallower depth ranges in the mouth. Information theory-based model selection provided a strong empirical support to the depth- and section-dependent salinity, but not temperature, effects on the three biodiversity metrics. Erect algae and the edible mussel Aulacomya atra numerically dominated in shallow water (0–3 m) at the head and the middle of the fjord, coinciding with the horizontal extension of the low-density water layer—these taxa were further replaced by the crustose algae Lithothamnion sp. and deep-dwelling suspension filters (e.g., corals, polychaetes, and sponges) along depth gradient. Macrobenthic biodiversity correlated, therefore, with the influence of freshwater inputs and the density-driven stratification of the water column in this ecosystem. The spatially variable (across both, horizontal and vertical fjord axes) thresholds observed in our study question the widely accepted pattern of increasing biodiversity with increasing distance from the head of estuarine ecosystems. Finally, non-linear environmental stress models provide us a strong predictive power to understand the responses of these unique ecosystems to natural and anthropogenic environmental changes.

Analyzing speech in both time and space: Generalized additive mixed models can uncover systematic patterns of variation in vocal tract shape in real-time MRI

We present a method of using generalized additive mixed models (GAMMs) to analyze midsagittal vocal tract data obtained from real-time magnetic resonance imaging (rt-MRI) video of speech production. Applied to rt-MRI data, GAMMs allow for observation of factor effects on vocal tract shape throughout two key dimensions: time (vocal tract change over the temporal course of a speech segment) and space (location of change within the vocal tract). Examples of this method are provided for rt-MRI data collected at a temporal resolution of 20 ms and a spatial resolution of 1.41 mm, for 36 native speakers of German. The rt-MRI data were quantified as 28-point semi-polar-grid aperture functions. Three test cases are provided as a way of observing vocal tract differences between: (1) /aː/ and /iː/, (2) /aː/ and /aɪ/, and (3) accentuated and unstressed /aː/. The results for each GAMM are independently validated using functional linear mixed models (FLMMs) constructed from data obtained at 20% and 80% of the vowel interval. In each case, the two methods yield similar results. In light of the method similarities, we propose that GAMMs are a robust, powerful, and interpretable method of simultaneously analyzing both temporal and spatial effects in rt-MRI video of speech.

Thermal limits of summer-collected Pardosa wolf spiders (Araneae: Lycosidae) from the Yukon Territory (Canada) and Greenland

Arctic and sub-Arctic terrestrial ectotherms contend with large daily and seasonal temperature ranges. However, there are few data available on the thermal biology of these high-latitude species, especially arachnids. We determined the lower and upper thermal limits of seven species of wolf spider from the genus Pardosa (Araneae: Lycosidae) collected in summer from the Yukon Territory (Canada) and Southern Greenland. None of these species survived freezing, and while spiderlings appeared freeze-avoidant, surviving to their supercooling point (SCP, the temperature at which they spontaneously freeze), chill-susceptible adults and juveniles died at temperatures above their SCP. The critical thermal minimum (CTmin, the lower temperature of activity) and SCP were very close (spiders continued moving until they freeze), and at − 5.4 to − 8.4 °C, are not substantially lower than those of lower-latitude species. The SCP of spiderlings was significantly lower than that of overwintering juveniles or adults, likely because of their small size. There was no systematic variation in SCP among collection sites, latitude, or species. Critical thermal maxima (CTmax) ranged from + 42.3 to + 46.8 °C, showed no systematic patterns of variation, and were also similar to those of lower-latitude relatives. Overall, heat tolerances of the Pardosa spp. were likely sufficient to tolerate even very warm Arctic summer temperatures, but cold tolerance is probably inadequate to survive winter conditions. We expect that seasonal thermal plasticity is necessary for overwintering in these species.

Capability of Biowaste Composite of High Density Polythene with Egg Shell and Wood Sawdust for Sorption of Heavy Metals in Industrial Waste Water

The health hazards posed by heavy metals in water and the need to mitigate the hazards have attracteda flurry of research interests on the technologies and methods of removing them from water. The industrial waste waterfrom a gutter within the neighbourhood of the Delta Shopping Mall in Effurun was used to test the heavy metal sorptioncapacity of the waste high density polythene and biowaste composites compounded by the author using a locallyconstructed extruder. Some of the physico – chemical properties of the waste water determined with PH Kent meter (model7020) and Hach conductivity meter (C0150) where within WHO acceptable limits while some were not. The metalconcentrations were determined using Atomic Absorption Spectrometer(Perkin Elmer Absorption Analyst 400 model)The Composite of 2:1.5:0.5 (HDPE: saw dust: egg shell) sorbed the highest concentration of the metals ( 0.168mg/L, Fe;0.072mg/L, Ni and 0.082mg/L, Cr than the other composites of 1.5: 1: 1.5 and 2:1:1 except Cd while the composite, 2:1:1sorbed the least concentration of metals( 0.061mg/L, Fe; 0.044mg/L, Ni; 0.071mg/L, Cr and 0.002mg/L, Cd during thefirst 24 hours of sorption exposure. Chromium was the most sorbed metal, 97.6% while cadmium was the least, 20.0%.There was no systematic pattern of variation for metal absorption in the next 24 hours due probably to the blocking of thepore sites during the first twenty four hours of sorption exposure. The composite, 2:1.5:0.5 exhibited a good potential asan economic heavy metal sorbent.Keywords: Sorption capacity, heavy metals, composites, waste water, extruder

Sexual size dimorphism in Ground Beetles and its modeling in latitude gradient Primary tabs

Large-scale systematic patterns of variation lie in the heart of organismic biology and have interested biologists ever since the beginning. These are most obvious in terms of body size, probably the single most important quantitative trait of an individual. In this relation Ground Beetles are poorly studied, though they are regarded to be sensitive to environmental changes and are accepted bioindicators. Beetles were sampled in 8 provinces of Russia, situated at different latitudes. We measured elytra length in six paleartic eurytopic species of carabids. We used mixed linear models to infer the mean latitude effect on size and sexual dimorphism of females and males. Regression coefficients in both sexes were negative and differed in different species. In C. cancellatus, C.hortensis, P. niger modulus of regression coefficients were larger in females, then, in that species females were more variable than males. In C. granulates and P. melanarius modulus of regression coefficients were larger in males, then, in those species males were more variable in latitude gradient. It is noteworthy that species, sharing the same ecological niches, had different strategies in realizing sex – specific body size variation in latitude gradient. E. g., C. granulatus - C. cancellatus, P. niger - P. melanarius. In general body size decreased in latitude gradient both in females and males. Shifts were steeper in Carabus species, than in Pterostichus. Despite SSD occurred in some analyzed latitudes and mainly at the margins of area, modeling results did not confirm opinion that SSD systematically changes in latitude gradient.

The cultural evolution of national constitutions

We explore how ideas from infectious disease and genetics can be used to uncover patterns of cultural inheritance and innovation in a corpus of 591 national constitutions spanning 1789–2008. Legal “ideas” are encoded as “topics”—words statistically linked in documents—derived from topic modeling the corpus of constitutions. Using these topics we derive a diffusion network for borrowing from ancestral constitutions back to the US Constitution of 1789 and reveal that constitutions are complex cultural recombinants. We find systematic variation in patterns of borrowing from ancestral texts and “biological”‐like behavior in patterns of inheritance, with the distribution of “offspring” arising through a bounded preferential‐attachment process. This process leads to a small number of highly innovative (influential) constitutions some of which have yet to have been identified as so in the current literature. Our findings thus shed new light on the critical nodes of the constitution‐making network. The constitutional network structure reflects periods of intense constitution creation, and systematic patterns of variation in constitutional lifespan and temporal influence.

Attractor States in Teaching and Learning Processes: A Study of Out-of-School Science Education.

In order for out-of-school science activities that take place during school hours but outside the school context to be successful, instructors must have sufficient pedagogical content knowledge (PCK) to guarantee high-quality teaching and learning. We argue that PCK is a quality of the instructor-pupil system that is constructed in real-time interaction. When PCK is evident in real-time interaction, we define it as Expressed Pedagogical Content Knowledge (EPCK). The aim of this study is to empirically explore whether EPCK shows a systematic pattern of variation, and if so whether the pattern occurs in recurrent and temporary stable attractor states as predicted in the complex dynamic systems theory. This study concerned nine out-of-school activities in which pupils of upper primary school classes participated. A multivariate coding scheme was used to capture EPCK in real time. A principal component analysis of the time series of all the variables reduced the number of components. A cluster revealed general descriptions of the components across all cases. Cluster analyses of individual cases divided the time series into sequences, revealing High-, Low-, and Non-EPCK states. High-EPCK attractor states emerged at particular moments during activities, rather than being present all the time. Such High-EPCK attractor states were only found in a few cases, namely those where the pupils were prepared for the visit and the instructors were trained.

Systematic variation in the stable hydrogen isotope (δ2H) composition of fur from summer populations of two species of temperate insectivorous bats

Stable hydrogen isotope techniques are increasingly used to investigate the migratory ecology of bats. This approach relies on the presence of predictable continental scale patterns in the stable hydrogen isotope composition of bat fur (δ2Hfur). While these patterns have been demonstrated repeatedly, there is local variation in δ2Hfur and the systematic patterns of variation are not well described for many bat species. We investigated local scale δ2Hfur variation in two species of North American bats, little brown myotis (Myotis lucifugus) and eastern red bats (Lasiurus borealis) obtained at two sites in southwestern Ontario. We found systematic differences in the δ2Hfur of multiple fur samples taken from the same bat, between mothers and their dependent young, and over the course of the summer season. We found substantial differences in the δ2Hfur profiles of two species from the same location as well as between populations of the same species at different but proximate locations. Our results inform sampling protocols for future stable hydrogen isotope investigations of bat ecology.

Factor Association with Multiple Correspondence Analysis in Vehicle–Pedestrian Crashes

In the United States, about 14% of total crash fatalities are pedestrian related. In 2012, 4,743 pedestrians were killed, and 76,000 pedestrians were injured in vehicle–pedestrian crashes in the United States. Vehicle– pedestrian crashes have become a key concern in Louisiana as a result of the high percentage of fatalities there in recent years. In 2012, pedestrians accounted for 17% of total crash fatalities in the state. This study used multiple correspondence analysis (MCA), an exploratory data analysis method used to detect and represent underlying structures in a categorical data set, to analyze 8 years (2004 to 2011) of vehicle–pedestrian crashes in Louisiana. Pedestrian crash data are best represented as transactions of multiple categorical variables, so the use of MCA was a unique choice to determine the relationship of the variables and their significance. The findings indicated several nontrivial focus groups (e.g., drivers with high-occupancy vehicles, female drivers in bad weather conditions, and drivers distracted by mobile phone use). The associated geometric factors were hillcrest roadways, dip or hump aligned roadways, roadways with multiple lanes, and roadways with no lighting at night. Male drivers were seen to be relatively susceptible to severe and moderate injury crashes. Fatal pedestrian crashes were correlated to two-lane roadways with no lighting at night. The MCA method helped measure significant contributing factors and degrees of association between the factors through the analysis of the systematic patterns of variation with categorical data sets of pedestrian crashes. The findings from this study will help transportation professionals improve countermeasure selection strategies.

Debris-Carrying in Larval Chrysopidae: Unraveling Its Evolutionary History

AbstractLarval debris-carrying, which occurs in many insect taxa, is a remarkable behavioral trait with substantial life history significance. For the Chrysopidae, information on the topic is scattered, and the habit's diversity and evolutionary history are unassessed. Here, we compile a comprehensive, annotated catalog on chrysopid debris-carrying and its associated larval morphology, and we identify emerging systematic patterns of variation, from larval nakedness to the construction of elaborate packets. Then, we examine these patterns in the context of available phylogenies with two objectives: 1) to begin unraveling the evolutionary history of chrysopid debris-carrying and 2) to evaluate the current and potential role of larval morphology (including debris-carrying modifications) in classification and phylogeny of this family. Debris-carrying: the literature revealed that debris-carrying occurs in the chrysopoid fossil record and in all three extant chrysopid subfamilies, including those proposed as basal (Nothochrysinae, Apochrysinae). Nevertheless, the family's ancestral state remains unresolved. The habit may have evolved at least once in Nothochrysinae or been lost several times. Larvae from only one genus of Apochrysinae are known, and they are debris-carriers. Each of the four tribes of the third subfamily, Chrysopinae, has distinctive debris-carrying characteristics. In ankylopterygine larvae, debris-carrying modifications seem relatively conserved. Among the ant-associated belonopterygine genera, debris-carrying is either highly evolved or, in one case, possibly absent. Within the large chrysopine tribe, nakedness and debris-carrying appear to have evolved independently numerous times; also, some reversals may have occurred. With one possible exception, leucochrysine genera have debris-carrying larvae. Larval morphology: scrutiny of the literature showed that all chrysopid genera whose larvae are known exhibit characteristic suites of anatomical structures related to carrying debris. Moreover, larval morphology provides strong (synapomorphic) evidence for the monophyly of four of the seven suprageneric chrysopid taxa: the subfamily Nothochrysinae and three of the four tribes of Chrysopinae (Ankylopterygini, Belonopterygini, and Leucochrysini). Larval morphological and debris-carrying characteristics appear to support some, but not all, previously proposed generic relationships within the tribe Chrysopini. Given the demonstrated potential advantages for including larval characters in chrysopid phylogenetic studies, it is essential to enhance the pool of available larval data. Therefore, we propose that citizen-scientists be involved in gathering verifiable data and that systematists develop comprehensive data matrices for comparative larval studies.

Using Learning Study to improve the teaching and learning of accounting in a school in Brunei Darussalam

PurposeThis paper reports on how a group of secondary school teachers collaborated in a school‐based professional development called Learning Study to improve accounting students' performance on the drawing up of cash budgets.Design/methodology/approachIn drawing up cash budgets – the object of learning – a power point presentation incorporating systematic variation was designed to reduce the overwhelming mass of (often irrelevant) data normally presented to students in textbooks and examiners' reports as part of the solutions to cash budget problems. In total, three lessons were designed focusing on how the object of learning could be handled. In each lesson the critical aspects corresponding to the object of learning were identified and a systematic pattern of variation was applied.FindingsIt was found that student learning improved progressively over the three lessons.Originality/valueThere is evidence to suggest that this Learning Study has made an impact, not only on student learning but also on teacher learning, and has contributed in some way to creating a learning culture in this school.

Salience and the Social Meaning of Declarative Contours

Most studies exploring the social meaning of variation have focused on phonological variables at the segmental level. This article investigates the social meaning of intonational variation in the speech of three gay professionals. To examine how intonational meanings can be exploited as symbolic resources, this study takes an intraspeaker approach, inspecting declarative intonation patterns across three situations per speaker. The analysis reveals that speakers exhibit systematic patterns of variation on either of two levels—the frequency with which variants are employed or their phonetic manifestations—depending on the salience of variants. The social significance of these patterns is inferred by situating them in their discourse and ethnographic contexts. Importantly, intonational meaning surfaces in both the choice of a variant and its phonetic rendering. The categorical choice of a variant conveys pragmatic meaning, while the variant’s phonetic realization reflects the strength of its social meaning.

Variation in universal temperature dependence of biological rates

For more than a century, biologists have known that body temperature strongly affects the capacities and rates of organisms and thus is a key determinant of organismal performance and Darwinian fitness (1⇓–3). Although rate/temperature (RT) relationships have been quantified for many traits and taxa, interest in RT studies is being revitalized because RT relationships are relevant to predicting biological responses to climate warming (4), as well as to testing the metabolic theory of ecology (MTE), a thermodynamic model of the impacts of body size, temperature, and metabolism on broad-scale biological patterns (5, 6). In PNAS, Dell et al. (7) present a massive compilation of RT data, evaluate quantitative predictions of MTE, and analyze systematic patterns of variation in temperature sensitivity. Their findings both support and challenge MTE, and their analyses will prompt new insights into systematic variation in temperature sensitivity of biological traits.

Choroidal thickness following extrafoveal photodynamic treatment with verteporfin in patients with central serous chorioretinopathy

To evaluate the effect of verteporfin photodynamic treatment (PDT) on choroidal thickness in patients with central serous chorioretinopathy (CSC). Choroidal thickness was measured with enhanced depth imaging- optical coherence tomography (EDI-OCT) before and after verteporfin PDT (full-dose verteporfin, half-light dose) in 16 eyes in 16 patients with serous detachment of the fovea secondary to extrafoveal angiographic fluorescein leakage. Treatment was confined to the area of leakage, whereas choroidal thickness before and after treatment was assessed over a larger area of the fundus using OCT. Complete resolution of the serous detachment was seen in all 16 eyes within 1 month of extrafoveal PDT, while choroidal thickness in the area where PDT was applied decreased from 407 μm [mean; 95% confidence interval (CI(95) ) 356-458 μm] to 349 μm (mean; CI(95) 300-399 μm; p < 0.0001), and subfoveal choroidal thickness was reduced from 421 μm (mean; CI(95) 352-489 μm) to 346 μm (mean; CI(95) 278-414 μm; p = 0.0001). Initially, subfoveal choroidal thickness was significantly increased in the treated eye compared with the healthy fellow eye (mean 324 μm; CI(95) 273-376 μm; p = 0.0003), but after treatment, the difference was not significant. Photodynamic therapy of active CSC was followed by choroidal thickness reduction, not only locally but also at considerable distance from the treated area. Thus, the process that causes choroidal thickening in CSC appears to spread laterally within the choroid.

Exit Polling in a Cold Climate: The BBC–ITV Experience in Britain in 2005

SummaryConducting an exit poll to forecast the outcome of a national election in terms of both votes and seats is particularly difficult in Britain. No official information is available on how individual polling stations voted in the past, use of single-member plurality means that there is no consistent relationship between votes and seats, electors can choose to vote by post and most of those who vote in person do so late in the day. In addition, around one in every six intended exit poll respondents refuses to participate. Methods that were developed to overcome these problems, and their use in the successful 2005 British Broadcasting Corporation–Independent Television exit poll, are described and evaluated. The methodology included a panel design to allow the estimation of electoral change at local level, coherent multiple-regression modelling of multiparty electoral change to capture systematic patterns of variation, probabilistic prediction of constituency winners to account for uncertainty in projected constituency level shares, collection of information about the voting intentions of postal voters before polling day and access to interviewer guesses on the voting behaviour of refusals. The coverage and accuracy of the exit poll data are critically examined, the effect of key aspects of the statistical modelling of the data is assessed and some general lessons are drawn for the design and analysis of electoral exit polls.

Latitudinal gradient in species richness

What is the gradient? Amongst the earliest remarked, and best documented, of broad-scale spatial patterns of life on Earth is a trend for more species to be found towards lower latitudes. The latitudinal gradient in species richness is such that most extant eukaryote, perhaps also prokaryote, species are found in the tropics. Even when counted over quite small areas in which it is present, the species richness of a taxonomic group might commonly vary by orders of magnitude between high and low latitudes.How general is the gradient? The latitudinal gradient in species richness occurs in terrestrial, freshwater and marine realms, is repeated for local and regional assemblages, and has been documented for a wide range of taxonomic groups, including viruses, bacteria, plants, arthropods and vertebrates. There are some exceptions, but these tend foremost to concern relatively species-poor taxonomic groups. This said, for any group typically only at rather coarse spatial resolutions is the gradient one of relatively continuous increase in richness towards lower latitudes. More usually, it is quite variable, with substantial regions in which richness can be notably high or low in comparison with the broad trend, and the peak often being displaced from the equator. In particular, the gradient can be influenced by the shape of continents or ocean basins, marked discontinuities in environmental conditions, and major historical events (such as periods of glaciation). It is helpful to consider the gradient in the context of the wider patterns of spatial variation in richness of which it is a part, rather than in isolation.How long has the gradient persisted? It is strongly suspected that the latitudinal gradient in species richness has been a persistent feature of life on Earth for much of its history, although obviously the positions of land and water masses have shifted, and the geographic pattern of environmental conditions has altered dramatically. There is evidence, however, that for some particular groups of organisms that remain quite speciose the latitudinal gradient has become steeper through evolutionary time.Why does the gradient occur? Ultimately, the latitudinal gradient in species richness must be a consequence of a greater period of net diversification in the tropics, likely following the origins of life there, or higher speciation rates and/or lower extinction rates at low latitudes compared with other regions. There is evidence that many temperate clades had their origins in the tropics. The prevailing view is that the tropics seem also to have been a ‘cradle of diversity’ (with high speciation rates), and that they have served as a ‘museum of diversity’ (with low extinction rates). The balance between the two rates is not well understood, and is a topic of much research interest. Some empirical evidence suggests that rates of speciation may have been lower at low latitudes but, accompanied by sufficiently low extinction rates, have nonetheless led to higher richness in the tropics.The proximate reasons for any latitudinal differences in speciation and extinction rates continue to be much debated. It is difficult to disentangle the potential influences of the many abiotic and biotic variables that show systematic patterns of variation with latitude. In the absence of substantial constraints on water supply, high speciation rates in the tropics may have resulted from higher and more stable temperatures leading to high biological rates, and hence shorter generation times and higher mutation rates. Extinction rates may be lower in the tropics because of environmental conditions that support a greater and more stable biomass, enabling more species to persist at low abundances. Speciation rates may also have been heightened and extinction rates reduced by the greater extent of the tropics in the past, and the accumulation of species at higher latitudes may have been reduced by the historical adaptation of most clades to tropical environments.What are the consequences of the gradient for conservation? Perhaps the most obvious consequence of the latitudinal gradient in species richness is that maintenance of the absolute numbers of species on Earth, or at least reduction of their current rates of loss, requires disproportionate attention to be paid to conservation activities in the tropics. Indeed, global schemes for identifying priority areas for conservation almost invariably place the majority of these in the tropics. A high proportion of tropical species tend also to have rather limited geographic distributions, which means that conservation efforts need to be dispersed throughout much of the tropics.Are there other significant implications of the gradient? The vast majority of studies in biology have been conducted on organisms from mid- to high northern latitudes. This means that they have usually concerned species that exist under conditions, and perhaps face challenges, that are very different from those relevant to most extant species. The consequences for understanding of many facets of biology could be profound.

Children and adolescents' internal models of food-sharing behavior include complex evaluations of contextual factors.

This study examined internal representations of food sharing in 589 children and adolescents (8-19 years of age). Questionnaires, depicting a variety of contexts in which one person was asked to share a resource with another, were used to examine participants' expectations of food-sharing behavior. Factors that were varied included the value of the resource, the relation between the two depicted actors, the quality of this relation, and gender. Results indicate that internal models of food-sharing behavior showed systematic patterns of variation, demonstrating that individuals have complex contextually based internal models at all ages, including the youngest. Examination of developmental changes in use of individual patterns is consistent with the idea that internal models reflect age-specific patterns of interactions while undergoing a process of progressive consolidation.

Macroborers within coral framework at Discovery Bay, north Jamaica: species distribution and abundance, and effects on coral preservation

Macroboring organisms are recognised as key agents of reef framework modification and destruction, and while recent studies in the Pacific have improved understanding of spatial variations in macroboring community structure, and rates of macroboring within individual reefs, comparable studies from the Caribbean are largely lacking. This study assesses the distribution of macroboring species and the degree of framework infestation across the reefs at Discovery Bay, north Jamaica. Although individual species of borers exhibit variable distributions across the reef, relative abundances of the main groups of macroborers (sponges, bivalves, worms) illustrate clear distributional trends. Sponges are dominant at fore-reef sites, while sipunculan and polychaete worms are only of importance at back-reef/lagoon and shallow fore-reef sites. Bivalves are locally important within back-reef and lagoon patch reef framework. Average percentages of internal bioerosion (macroboring) vary between sites, but are highest at back-reef and deep fore-reef sites. No systematic pattern of variation occurs within back-reef/lagoon samples, but a significant trend of increased macroboring is recognised with increased water depth on the fore-reef. In addition, significant differences in terms of the susceptibility of individual coral species are recognised. These factors are likely to result in biasing of the fossil record, with variable styles of preservation evident both between sites (i.e. with depth/environment) and within sites (i.e. between coral species).

Generalizations about trust in marketing channel relationships using meta-analysis

This meta-analysis examines the role of trust in marketing channels. First, the analysis of pairwise relationships involving trust indicates that trust, on average, exhibits a robust and strong relationship with other channel relationship constructs under a wide range of different conditions. Next, we explored systematic patterns of variation in the correlations. The results demonstrate that the use of experiments, samples drawn from multiple industries, and US data tend to produce larger effects than the use of field studies, samples drawn from a single industry, and European data respectively do. Various other methodological characteristics of studies did not have significant effects. Finally, we examined the role of trust in a nomological net, involving some of the most frequently studied antecedents and consequences of trust. We find that trust contributes to satisfaction and long-term orientation over and beyond the effects of economic outcomes of the relationship. Both trust and economic outcomes—not just one or the other—are conducive to relationship marketing success.