Effect of land use change on the carbon cycle in Amazon soils

The overall goal of this study was to provide a quantitative understanding of the cycling of carbon in the soils associated with deep-rooting Amazon forests. In particular, we wished to apply the understanding gained by answering two questions: (1) what changes will accompany the major land use change in this region, the conversion of forest to pasture? and (2) what is the role of carbon stored deeper than one meter in depth in these soils? To construct carbon budgets for pasture and forest soils we combined the following: measurements of carbon stocks in above-ground vegetation, root biomass, detritus, and soil organic matter; rates of carbon inputs to soil and detrital layers using litterfall collection and sequential coring to estimate fine root turnover; C-14 analyses of fractionated SOM and soil CO2 to estimate residence times; C-13 analyses to estimate C inputs to pasture soils from C-4 grasses; soil pCO2, volumetric water content, and radon gradients to estimate CO2 production as a function of soil depth; soil respiration to estimate total C outputs; and a model of soil C dynamics that defines SOM fractions cycling on annual, decadal, and millennial time scales

PATAXÓ: A Framework to Allow Updates Through XML Views

XML has become an important medium for data exchange, and is frequently used as an interface to (i.e., a view of) a relational database. Although a lot of work has been done on querying relational databases through XML views, the problem of updating relational databases through XML views has not received much attention. In this work, we map XML views expressed using a subset of XQuery to a corresponding set of relational views. Thus, we transform the problem of updating relational databases through XML views into a classical problem of updating relational databases through relational views. We then show how updates on the XML view are mapped to updates on the corresponding relational views. Existing work on updating relational views can then be leveraged to determine whether or not the relational views are updatable with respect to the relational updates, and if so, to translate the updates to the underlying relational database

EXPedite: A System for Encoded XML Processing

As XML becomes an increasingly popular format for information exchange, the efficient processing of broadcast XML data on a constrained device (for example, a cell phone or a PDA) becomes a critical task. In this paper we present the EXPedite system: a new model of data processing in an information exchange environment, which migrates the power of the data-sending server to receivers for efficient processing. It consists of a simple and general encoding scheme for servers, and streaming query processing algorithms on encoded XML stream for data receivers with constrained computing abilities. Experiments show the impressive performance of EXPedite

Completing below-ground carbon budgets for pastures, recovering forests, and mature forests of Amazonia

The objective of this grant was to complete below-ground carbon budgets for pastures and forest soils in the Amazon. Profiles of radon and carbon dioxide were used to estimate depth distribution of CO2 production in soil. This information is necessary for determining the importance of deep roots as sources of carbon inputs. Samples were collected for measuring root biomass from new research sites at Santana de Araguaia and Trombetas. Soil gases will be analyzed for CO2 and (14)CO2, and soil organic matter will be analyzed for C-14. Estimates of soil texture from the RADAMBRASIL database were merged with climate data to calculate soil water extraction by forest canopies during the dry season. In addition, a preliminary map of areas where deep roots are needed for deep soil water was produced. A list of manuscripts and papers prepared during the reporting periods is given

Theoretical Aspects of Schema Merging

A general technique for merging database schemas is developed that has a number of advantages over existing techniques, the most important of which is that schemas are placed in a partial order that has bounded joins. This means that the merging operation, when it succeeds, is both associative and commutative, i.e., that the merge of schemas is independent of the order in which they are considered — a property not possessed by existing methods. The operation is appropriate for the design of interactive programs as it allows user assertions about relationships between nodes in the schemas to be considered as elementary schemas. These can be combined with existing schemas using precisely the same merging operation. The technique is general and can be applied to a variety of data models. It can also deal with certain cardinality constraints that arise through the imposition of keys. A prototype implementation, together with a graphical interface, has been developed.

Inductions from novel categories: The role of language and conceptual structure

Young children expect members of a familiar category to share nonobvious properties. The present experiments were designed to determine whether children expect unfamiliar objects with the same novel label to share nonobvious properties. In three experiments, 4-and 5-year-old children were taught properties about unfamiliar objects (e.g., a gnu-like animal) and then were tested on their generalization of each property to four test objects. The test objects were either similar or dissimilar in appearance to the target and received either the same or a different novel label from that of the target. When category labels and appearances were completely independent of one another, children drew inferences based on appearances rather than novel category labels. However, when the same pictures received familiar labels (e.g., a cow, a deer) instead of novel labels (e.g., a fep, a wug), children drew inferences based on category labels as well as appearances. Furthermore, children did draw inferences on the basis of novel labels when perceptual cues were not completely discrepant from the labels. These results suggest that novel labels help guide children's inferences from unfamiliar categories, but only when the conceptual basis of the names is clear.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28641/1/0000455.pd

Blood Pressure Reactivity to an Anger Provocation Interview Does Not Predict Incident Cardiovascular Disease Events: The Canadian Nova Scotia Health Survey (NSHS95) Prospective Population Study

We examined the association between blood pressure (BP) reactivity to an anger provocation interview and 10-year incident CVD events in 1,470 adults from the population-based 1995 Nova Scotia Health Survey (NSHS95). In an unadjusted model, those in the highest decile of systolic BP reactivity were more than twice as likely to have an incident CVD event compared to those in the decile with no reactivity (HR = 2.33, 95% CI = 1.15 – 4.69, P = 0.02). However, after adjusting for age and sex, and then also for Framingham risk score, body mass index, and education, this relationship was attenuated and not statistically significant. Diastolic BP reactivity was not associated with CVD incidence in any model. Individual differences in BP reactivity to a laboratory-induced, structured anger provocation interview may not play a major role in clinical CVD endpoints

Self-Esteem in Second Life: An inWorld Group Intervention for Women with Disabilities

We are developing and investigating the feasibility of a self-esteem enhancement intervention in Second Life for women with physical disabilities. We adapted the curriculum of a previously tested workshop intervention to include features unique to this environment. Results of the beta test were very positive. Everyone involved showed considerable enthusiasm for exploring the new world of SL. The group leaders were challenged to resolve technical problems on every occasion, but these diminished and were perceived as manageable as the intervention progressed. Beta testers gave positive ratings to the information presented, organization, and usefulness of the intervention and found it very enjoyable although fatigue and stress limited the participation of some. They appreciated the use of Internet technology as an accommodation to their disability, in place of requiring transportation and additional energy expenditure to attend face-to-face meetings. Research issues related to engagement, measurement, and participant safety, as well as future research directions, are discussed. We conclude that SL has great potential for delivering health promotion interventions to women with physical disabilities

Drought effects on litterfall, wood production and belowground carbon cycling in an Amazon forest: results of a throughfall reduction experiment

The Amazon Basin experiences severe droughts that may become more common in the future. Little is known of the effects of such droughts on Amazon forest productivity and carbon allocation. We tested the prediction that severe drought decreases litterfall and wood production but potentially has multiple cancelling effects on belowground production within a 7-year partial throughfall exclusion experiment. We simulated an approximately 35–41% reduction in effective rainfall from 2000 through 2004 in a 1 ha plot and compared forest response with a similar control plot. Wood production was the most sensitive component of above-ground net primary productivity (ANPP) to drought, declining by 13% the first year and up to 62% thereafter. Litterfall declined only in the third year of drought, with a maximum difference of 23% below the control plot. Soil CO2 efflux and its 14C signature showed no significant treatment response, suggesting similar amounts and sources of belowground production. ANPP was similar between plots in 2000 and declined to a low of 41% below the control plot during the subsequent treatment years, rebounding to only a 10% difference during the first post-treatment year. Live aboveground carbon declined by 32.5 Mg ha−1 through the effects of drought on ANPP and tree mortality. Results of this unreplicated, long-term, large-scale ecosystem manipulation experiment demonstrate that multi-year severe drought can substantially reduce Amazon forest carbon stocks