Showing papers by "University of New Hampshire published in 2006"

A Global Crisis for Seagrass Ecosystems

Abstract: Seagrasses, marine flowering plants, have a long evolutionary history but are now challenged with rapid environmental changes as a result of coastal human population pressures. Seagrasses provide key ecological services, including organic carbon production and export, nutrient cycling, sediment stabilization, enhanced biodiversity, and trophic transfers to adjacent habitats in tropical and temperate regions. They also serve as “coastal canaries,” global biological sentinels of increasing anthropogenic influences in coastal ecosystems, with large-scale losses reported worldwide. Multiple stressors, including sediment and nutrient runoff, physical disturbance, invasive species, disease, commercial fishing practices, aquaculture, overgrazing, algal blooms, and global warming, cause seagrass declines at scales of square meters to hundreds of square kilometers. Reported seagrass losses have led to increased awareness of the need for seagrass protection, monitoring, management, and restoration. However, seagrass science, which has rapidly grown, is disconnected from public awareness of seagrasses, which has lagged behind awareness of other coastal ecosystems. There is a critical need for a targeted global conservation effort that includes a reduction of watershed nutrient and sediment inputs to seagrass habitats and a targeted educational program informing regulators and the public of the value of seagrass meadows.

The Reification of Absorptive Capacity: A Critical Review and Rejuvenation of the Construct

Abstract: We conduct a detailed analysis of 289 absorptive capacity papers from 14 journals to assess how the construct has been utilized, examine the key papers in the field, and identify the substantive contributions to the broader literature using a thematic analysis. We argue that research in this area is fundamentally driven by five critical assumptions that we conclude have led to its reification and that this reification has led to stifling of research in this area. To address this, we propose a model of absorptive capacity processes, antecedents, and outcomes.

Bacterial and Fungal Contributions to Carbon Sequestration in Agroecosystems

Abstract: This paper reviews the current knowledge of microbial processes affecting C sequestration in agroecosystems. The microbial contribution to soil C storage is directly related to microbial community dynamics and the balance between formation and degradation of microbial byproducts. Soil microbes also indirectly influence C cycling by improving soil aggregation, which physically protects soil organic matter (SOM). Consequently, the microbial contribution to C sequestration is governed by the interactions between the amount of microbial biomass, microbial community structure, microbial byproducts, and soil properties such as texture, clay mineralogy, pore-size distribution, and aggregate dynamics. The capacity of a soil to protect microbial biomass and microbially derived organic matter (MOM) is directly and/or indirectly (i.e., through physical protection by aggregates) related to the reactive properties of clays. However, the stabilization of MOM in the soil is also related to the efficiency with which microorganisms utilize substrate C and the chemical nature of the byproducts they produce. Crop rotations, reduced or no-tillage practices, organic farming, and cover crops increase total microbial biomass and shift the community structure toward a more fungal-dominated community, thereby enhancing the accumulation of MOM. A quantitative and qualitative improvement of SOM is generally observed in agroecosystems favoring a fungal-dominated community, but the mechanisms leading to this improvement are not completely understood. Gaps within our knowledge on MOM-C dynamics and how they are related to soil properties and agricultural practices are identified.

The global abundance and size distribution of lakes, ponds, and impoundments

Abstract: One of the major impediments to the integration of lentic ecosystems into global environmental analyses has been fragmentary data on the extent and size distribution of lakes, ponds, and impoundments. We use new data sources, enhanced spatial resolution, and new analytical approaches to provide new estimates of the global abundance of surface-water bodies. A global model based on the Pareto distribution shows that the global extent of natural lakes is twice as large as previously known (304 million lakes; 4.2 million km2 in area) and is dominated in area by millions of water bodies smaller than 1 km2. Similar analyses of impoundments based on inventories of large, engineered dams show that impounded waters cover approximately 0.26 million km 2 . However, construction of low-tech farm impoundments is estimated to be between 0.1% and 6% of farm area worldwide, dependent upon precipitation, and represents .77,000 km 2 globally, at present. Overall, about 4.6 million km2 of the earth’s continental ‘‘land’’ surface (.3%) is covered by water. These analyses underscore the importance of explicitly considering lakes, ponds, and impoundments, especially small ones, in global analyses of rates and processes.

Oxidative stress in marine environments: biochemistry and physiological ecology.

Abstract: Oxidative stress-the production and accumulation of reduced oxygen intermediates such as superoxide radicals, singlet oxygen, hydrogen peroxide, and hydroxyl radicals-can damage lipids, proteins, and DNA. Many disease processes of clinical interest and the aging process involve oxidative stress in their underlying etiology. The production of reactive oxygen species is also prevalent in the world's oceans, and oxidative stress is an important component of the stress response in marine organisms exposed to a variety of insults as a result of changes in environmental conditions such as thermal stress, exposure to ultraviolet radiation, or exposure to pollution. As in the clinical setting, reactive oxygen species are also important signal transduction molecules and mediators of damage in cellular processes, such as apoptosis and cell necrosis, for marine organisms. This review brings together the voluminous literature on the biochemistry and physiology of oxidative stress from the clinical and plant physiology disciplines with the fast-increasing interest in oxidative stress in marine environments.

Deploying a wireless sensor network on an active volcano

Abstract: Augmenting heavy and power-hungry data collection equipment with lighten smaller wireless sensor network nodes leads to faster, larger deployments. Arrays comprising dozens of wireless sensor nodes are now possible, allowing scientific studies that aren't feasible with traditional instrumentation. Designing sensor networks to support volcanic studies requires addressing the high data rates and high data fidelity these studies demand. The authors' sensor-network application for volcanic data collection relies on triggered event detection and reliable data retrieval to meet bandwidth and data-quality demands.

Psychological resilience, positive emotions, and successful adaptation to stress in later life.

Abstract: In 3 studies, the authors investigated the functional role of psychological resilience and positive emotions in the stress process. Studies 1a and 1b explored naturally occurring daily stressors. Study 2 examined data from a sample of recently bereaved widows. Across studies, multilevel random coefficient modeling analyses revealed that the occurrence of daily positive emotions serves to moderate stress reactivity and mediate stress recovery. Findings also indicated that differences in psychological resilience accounted for meaningful variation in daily emotional responses to stress. Higher levels of trait resilience predicted a weaker association between positive and negative emotions, particularly on days characterized by heightened stress. Finally, findings indicated that over time, the experience of positive emotions functions to assist high-resilient individuals in their ability to recover effectively from daily stress. Implications for research into protective factors that serve to inhibit the scope, severity, and diffusion of daily stressors in later adulthood are discussed.

Reconciling carbon-cycle concepts, terminology, and methods

Abstract: Recent projectionsofclimatic change havefocused a great deal of scientific and public attention on patterns of carbon (C) cycling as well as its controls, particularly the factors that determine whether an ecosystem is a net source or sink of atmospheric carbon dioxide (CO2). Net ecosystem production (NEP), a central concept in C-cycling research, has been used by scientists to represent two different concepts. We propose that NEP be restricted to just one of its two original definitions—the imbalance between gross primary production (GPP) and ecosystem respiration (ER). We further propose that a new term—net ecosystem carbon balance (NECB)—be applied to the net rate of C accumulation in (or loss from [negative sign]) ecosystems. Net ecosystem carbon balance differs from NEP when C fluxesotherthanCfixationandrespiration occur,or when inorganic C enters or leaves in dissolved form. These fluxes include the leaching loss or lateral transfer of C from the ecosystem; the emission of volatile organic C, methane, and carbon monoxide; and the release of soot and CO2 from fire. Carbon fluxes in addition to NEP are particularly important determinants of NECB over long time scales. However, even over short time scales, they are important in ecosystems such as streams, estuaries, wetlands, and cities. Recent technological advances have led to a diversity of approaches to the measurement of C fluxes at different temporal and spatial scales. These approaches frequently capture different components of NEP or NECB and can therefore be compared across scales only by carefully specifying the

What is Democratic Education

Abstract: Why does education matter in a democratic society and in particular, why does higher education matter? What should a democratic education be like, and who should decide how future citizens will be educated? These questions suggest that education is a political matter as much as it is about teaching and curriculum. Plato understood this when he placed education at the center of his construction of the ideal Republic. Thomas Jefferson also understood this from the earliest days of the democratic revolution in America. In 1779, Jefferson submitted a bill to the Virginia legislature that, had it passed, would have provided a system of education from primary school through university at public expense. His “Bill for the More General Diffusion of Knowledge” included a selection system through which young men (yes, only young men) of ability could rise through the system to university education regardless of family background and means.1 He offered three interconnected rationales. First, ignorance enslaved the mind, and only education could liberate people from the powers of tyrants and the superstitions of priests. Second, publicly supported education would break down the artificial, inherited aristocracy that was characteristic of Europe and would replace it with an egalitarian society. Finally, Jefferson also well knew the inherent risks when the people rule. The rule of the people can so easily degenerate into the tyranny of the many. It has been said that in a democracy, one depends on the wisdom of strangers. It is, therefore, in our mutual interest to support the education, including higher education, of citizens in a democracy, since our fate depends on them. This was a new and radical idea, because it rested on a new and radical conception of citizenship. How should we educate citizens for democracy? How we answer this question depends, in part, on what we think about democracy. Too often we identify democracy with such institutions as voting, representative government, the rule of law, constitutional protections of individual rights, and so forth. As important as these are, democracy is more than this. John Dewey observed that “a democracy is more than a form of government; it is primarily a mode of associated living, of conjoint communicated experience” in which we understand our own actions and interests in relation to shared concerns of other citizens.2 At its core, a democratic form of life is grounded in respect for individuals and our recognition of an obligation to come together with other individuals to make decisions about our common good. This is more difficult than it sounds in a pluralist society such as ours. We often bring very different backgrounds and moral and religious perspectives to many of the issues that we must decide as a people. Think, for example, of the war in Iraq, of abortion policy, or of support for embryonic stem cell research. Our disagreement about the best policy is often based on fundamental differences in basic moral and political values—on different views about America’s role in the world, for example, or the right to life vs. right to choice, or when life begins. In a pluralist democracy, can anyone legitimately claim to be in possession of the truth of the matter and declare that opposing views are false? Plato wanted a philosopher king—someone who had ultimate wisdom—to rule. But in a democracy, the people rule (which is why Plato disliked democracy). And in a pluralistic democracy, the people often disagree about fundamental values, yet we still must make decisions that bind us all. Political philosopher Benjamin Barber once observed that “democracy begins where certainty ends.” 3 For him, the political world is necessarily uncertain; a world in which reasonable people can come to very different conclusions, a world in which we must recognize that other citizens have different values and also recognize the fallibility of our own best judgments. How should citizens and future citizens be educated for the challenges of a pluralistic democracy?

Effective sea-level rise and deltas: Causes of change and human dimension implications

Abstract: An assessment is made of contemporary effective sea-level rise (ESLR) for a sample of 40 deltas distributed worldwide. For any delta, ESLR is a net rate, defined by the combination of eustatic sea-level rise, the natural gross rate of fluvial sediment deposition and subsidence, and accelerated subsidence due to groundwater and hydrocarbon extraction. ESLR is estimated under present conditions using a digital data set of delta boundaries and a simple model of delta dynamics. The deltas in this study represent all major climate zones, levels of population density, and degrees of economic development. Collectively, the sampled deltas serve as the endpoint for river basins draining 30% of the Earth's landmass, and 42% of global terrestrial runoff. Nearly 300 million people inhabit these deltas. For the contemporary baseline, ESLR estimates range from 0.5 to 12.5 mm yr −1 . Decreased accretion of fluvial sediment resulting from upstream siltation of artificial impoundments and consumptive losses of runoff from irrigation are the primary determinants of ESLR in nearly 70% of the deltas. Approximately 20% of the deltas show accelerated subsidence, while only 12% show eustatic sea-level rise as the predominant effect. Extrapolating contemporary rates of ESLR through 2050 reveals that 8.7 million people and 28,000 km 2 of deltaic area in the sample set of deltas could suffer from enhanced inundation and increased coastal erosion. The population and area inundated rise significantly when considering increased flood risk due to storm surge. This study finds that direct anthropogenic effects determine ESLR in the majority of deltas studied, with a relatively less important role for eustatic sea-level rise. Serious challenges to human occupancy of deltaic regions worldwide are thus conveyed by factors which to date have been studied less comprehensively than the climate change–sea-level rise question. © 2005 Elsevier B.V. All rights reserved.

Fidelity and yield in a volcano monitoring sensor network

Abstract: We present a science-centric evaluation of a 19-day sensor network deployment at Reventador, an active volcano in Ecuador. Each of the 16 sensors continuously sampled seismic and acoustic data at 100 Hz. Nodes used an event-detection algorithm to trigger on interesting volcanic activity and initiate reliable data transfer to the base station. During the deployment, the network recorded 229 earthquakes, eruptions, and other seismoacoustic events.The science requirements of reliable data collection, accurate event detection, and high timing precision drive sensor networks in new directions for geophysical monitoring. The main contribution of this paper is an evaluation of the sensor network as a scientific instrument, holding it to the standards of existing instrumentation in terms of data fidelity (the quality and accuracy of the recorded signals) and yield (the quantity of the captured data). We describe an approach to time rectification of the acquired signals that can recover accurate timing despite failures of the underlying time synchronization protocol. In addition, we perform a detailed study of the sensor network's data using a direct comparison to a standalone data logger, as well as an investigation of seismic and acoustic wave arrival times across the network.

A comparison of global estimates of marine primary production from ocean color

Abstract: The third primary production algorithm round robin (PPARR3) compares output from 24 models that estimate depth-integrated primary production from satellite measurements of ocean color, as well as seven general circulation models (GCMs) coupled with ecosystem or biogeochemical models. Here we compare the global primary production fields corresponding to eight months of 1998 and 1999 as estimated from common input fields of photosynthetically-available radiation (PAR), sea-surface temperature (SST), mixed-layer depth, and chlorophyll concentration. We also quantify the sensitivity of the ocean-color-based models to perturbations in their input variables. The pair-wise correlation between ocean-color models was used to cluster them into groups or related output, which reflect the regions and environmental conditions under which they respond differently. The groups do not follow model complexity with regards to wavelength or depth dependence, though they are related to the manner in which temperature is used to parameterize photosynthesis. Global average PP varies by a factor of two between models. The models diverged the most for the Southern Ocean, SST under 10 degrees C, and chlorophyll concentration exceeding 1 mg Chlm(-3). Based on the conditions under which the model results diverge most, we conclude that current ocean-color-based models are challenged by high-nutrient low-chlorophyll conditions, and extreme temperatures or chlorophyll concentrations. The GCM-based models predict comparable primary production to those based on ocean color: they estimate higher values in the Southern Ocean, at low SST, and in the equatorial band, while they estimate lower values in eutrophic regions (probably because the area of high chlorophyll concentrations is smaller in the GCMs). Further progress in primary production modeling requires improved understanding of the effect of temperature on photosynthesis and better parameterization of the maximum photosynthetic rate. (c) 2006 Elsevier Ltd. All rights reserved.

Salesperson Adaptive Selling Behavior and Customer Orientation: A Meta-Analysis

Abstract: The authors combine findings from 155 samples of more than 31,000 salespeople to test alternative models of antecedents and consequences of adaptive selling behavior (ASB) and customer orientation (CO). A random-effects meta-analysis yields average values for 28 different correlations ranging from −.16 to .35, 19 of which are significant. Controlling for salesperson gender and selling experience, structural equation modeling indicates that ASB increases self-rated, manager-rated, and objective measures of performance, whereas CO increases only self-rated performance. Both ASB and CO increase job satisfaction. Tests of reciprocal relationships indicate that ASB increases CO and job satisfaction increases performance rather than vice versa. Selling experience increases performance but not job satisfaction, and saleswomen rate their performance and satisfaction slightly higher than salesmen do. The magnitudes of the relationships indicate that ASB and selling experience have greater effects than CO ...

Evaluation of remote sensing based terrestrial productivity from MODIS using regional tower eddy flux network observations

Abstract: The Moderate Resolution Spectroradiometer (MODIS) sensor has provided near real-time estimates of gross primary production (GPP) since March 2000. We compare four years (2000 to 2003) of satellite-based calculations of GPP with tower eddy CO2 flux-based estimates across diverse land cover types and climate regimes. We examine the potential error contributions from meteorology, leaf area index (LAI)/fPAR, and land cover. The error between annual GPP computed from NASA's Data Assimilation Office's (DAO) and tower-based meteorology is 28%, indicating that NASA's DAO global meteorology plays an important role in the accuracy of the GPP algorithm. Approximately 62% of MOD15-based estimates of LAI were within the estimates based on field optical measurements, although remaining values overestimated site values. Land cover presented the fewest errors, with most errors within the forest classes, reducing potential error. Tower-based and MODIS estimates of annual GPP compare favorably for most biomes, although MODIS GPP overestimates tower-based calculations by 20%-30%. Seasonally, summer estimates of MODIS GPP are closest to tower data, and spring estimates are the worst, most likely the result of the relatively rapid onset of leaf-out. The results of this study indicate, however, that the current MODIS GPP algorithm shows reasonable spatial patterns and temporal variability across a diverse range of biomes and climate regimes. So, while continued efforts are needed to isolate particular problems in specific biomes, we are optimistic about the general quality of these data, and continuation of the MOD17 GPP product will likely provide a key component of global terrestrial ecosystem analysis, providing continuous weekly measurements of global vegetation production

The large-scale freshwater cycle of the Arctic

Abstract: This paper synthesizes our understanding of the Arctic's large-scale freshwater cycle. It combines terrestrial and oceanic observations with insights gained from the ERA-40 reanalysis and land surface and ice-ocean models. Annual mean freshwater input to the Arctic Ocean is dominated by river discharge (38%), inflow through Bering Strait (30%), and net precipitation (24%). Total freshwater export from the Arctic Ocean to the North Atlantic is dominated by transports through the Canadian Arctic Archipelago (35%) and via Fram Strait as liquid (26%) and sea ice (25%). All terms are computed relative to a reference salinity of 34.8. Compared to earlier estimates, our budget features larger import of freshwater through Bering Strait and larger liquid phase export through Fram Strait. While there is no reason to expect a steady state, error analysis indicates that the difference between annual mean oceanic inflows and outflows (∼8% of the total inflow) is indistinguishable from zero. Freshwater in the Arctic Ocean has a mean residence time of about a decade. This is understood in that annual freshwater input, while large (∼8500 km3), is an order of magnitude smaller than oceanic freshwater storage of ∼84,000 km3. Freshwater in the atmosphere, as water vapor, has a residence time of about a week. Seasonality in Arctic Ocean freshwater storage is nevertheless highly uncertain, reflecting both sparse hydrographic data and insufficient information on sea ice volume. Uncertainties mask seasonal storage changes forced by freshwater fluxes. Of flux terms with sufficient data for analysis, Fram Strait ice outflow shows the largest interannual variability.

Examining characteristics and associated distress related to Internet harassment: findings from the Second Youth Internet Safety Survey.

Abstract: OBJECTIVE. We sought to identify the characteristics of youth who are targets of Internet harassment and characteristics related to reporting distress as a result of the incident. PARTICIPANTS AND METHODS. The Second Youth Internet Safety Survey is a national telephone survey of a random sample of 1500 Internet users between the ages of 10 and 17 years conducted between March and June 2005. Participants had used the Internet at least once a month for the previous 6 months. RESULTS. Nine percent of the youth who used the Internet were targets of online harassment in the previous year. Thirty-two percent of the targets reported chronic harassment (ie, harassment ≥3 times in the previous year). In specific incidents, almost half (45%) knew the harasser in person before the incident. Half of the harassers (50%) were reportedly male, and half (51%) were adolescents. One in 4 targets reported an aggressive offline contact (eg, the harasser telephoned, came to the youth9s home, or sent gifts); 2 in 3 disclosed the incident to another person. Among otherwise similar youth, the odds of being a target of Internet harassment were higher for those youth who harassed others online, reported borderline/clinically significant social problems, and were victimized in other contexts. Likewise, using the Internet for instant messaging, blogging, and chat room use each elevated the odds of being a target of Internet harassment versus those who did not engage in these online activities. All other demographic, Internet-use, and psychosocial characteristics were not related to reports of online harassment. Thirty-eight percent of the harassed youth reported distress as a result of the incident. Those who were targeted by adults, asked to send a picture of themselves, received an aggressive offline contact (eg, the harasser telephoned or came to the youth9s home), and were preadolescents were each significantly more likely to report distress because of the experience. Conversely, the youth who visited chat rooms were significantly less likely to be distressed by the harassment. CONCLUSIONS. Internet harassment can be a serious event for some youth. Because there has been a significant increase in the prevalence of Internet harassment from 2000 to 2005, adolescent health professionals should continue to be vigilant about such experiences in the lives of young people with whom they interact. Social problems and online aggressive behavior are each associated with elevated odds of being the target of harassment. Thus, prevention efforts may be best aimed at improving the interpersonal skills of young people who choose to communicate with others using these online tools. Adolescent health professionals should be especially aware of events that include aggressive offline contacts by adult harassers or asking the child or adolescent to send a picture of themselves, because each of these scenarios increase the odds of reporting distress by more than threefold. Findings further support the call for the inclusion of Internet-harassment prevention in conventional antibullying programs empowering schools to address Internet bullying situations that occur between students. This will not solve all situations, however. We also must encourage Internet service providers to partner with consumers to be proactive in serious harassment episodes that violate criminal laws and service-provider codes of conduct.

The underpinnings of land‐use history: three centuries of global gridded land‐use transitions, wood‐harvest activity, and resulting secondary lands

Abstract: To accurately assess the impacts of human land use on the Earth system, information is needed on the current and historical patterns of land-use activities. Previous global studies have focused on developing reconstructions of the spatial patterns of agriculture. Here, we provide the first global gridded estimates of the underlying land conversions (land-use transitions), wood harvesting, and resulting secondary lands annually, for the period 1700–2000. Using data-based historical cases, our results suggest that 42–68% of the land surface was impacted by land-use activities (crop, pasture, wood harvest) during this period, some multiple times. Secondary land area increased 10–44 × 106 km2; about half of this was forested. Wood harvest and shifting cultivation generated 70–90% of the secondary land by 2000; permanent abandonment and relocation of agricultural land accounted for the rest. This study provides important new estimates of globally gridded land-use activities for studies attempting to assess the consequences of anthropogenic changes to the Earth's surface over time.

Phenology of a northern hardwood forest canopy

Abstract: While commonplace in other parts of the world, long-term and ongoing observations of the phenology of native tree species are rare in North America. We use 14 years of field survey data from the Hubbard Brook Experimental Forest to fit simple models of canopy phenology for three northern hardwood species, sugar maple (Acer saccharum), American beech (Fagus grandifolia), and yellow birch (Betula alleghaniensis). These models are then run with historical meteorological data to investigate potential climate change effects on phenology. Development and senescence are quantified using an index that ranges from 0 (dormant, no leaves) to 4 (full, green canopy). Sugar maple is the first species to leaf out in the spring, whereas American beech is the last species to drop its leaves in the fall. Across an elevational range from 250 to 825 m ASL, the onset of spring is delayed by 2.7±0.4 days for every 100 m increase in elevation, which is in reasonable agreement with Hopkin's law. More than 90% of the variation in spring canopy development, and just slightly less than 90% of the variation in autumn canopy senescence, is accounted for by a logistic model based on accumulated degree-days. However, degree-day based models fit to Hubbard Brook data appear to overestimate the rate at which spring development occurs at the more southerly Harvard Forest. Autumn senescence at the Harvard Forest can be predicted with reasonable accuracy in sugar maple but not American beech. Retrospective modeling using five decades (1957–2004) of Hubbard Brook daily mean temperature data suggests significant trends (P≤0.05) towards an earlier spring (e.g. sugar maple, rate of change=0.18 days earlier/yr), consistent with other studies documenting measurable climate change effects on the onset of spring in both North America and Europe. Our results also suggest that green canopy duration has increased by about 10 days (e.g. sugar maple, rate of change=0.21 days longer/yr) over the period of study.

Using ecosystem engineers to restore ecological systems

Abstract: Ecosystem engineers affect other organisms by creating, modifying, maintaining or destroying habitats. Despite widespread recognition of these often important effects, the ecosystem engineering concept has yet to be widely used in ecological applications. Here, we present a conceptual framework that shows how consideration of ecosystem engineers can be used to assess the likelihood of restoration of a system to a desired state, the type of changes necessary for successful restoration and how restoration efforts can be most effectively partitioned between direct human intervention and natural ecosystem engineers.

CME Theory and Models

Abstract: This chapter provides an overview of current efforts in the theory and modeling of CMEs. Five key areas are discussed: (1) CME initiation; (2) CME evolution and propagation; (3) the structure of interplanetary CMEs derived from flux rope modeling; (4) CME shock formation in the inner corona; and (5) particle acceleration and transport at CME driven shocks. In the section on CME initiation three contemporary models are highlighted. Two of these focus on how energy stored in the coronal magnetic field can be released violently to drive CMEs. The third model assumes that CMEs can be directly driven by currents from below the photosphere. CMEs evolve considerably as they expand from the magnetically dominated lower corona into the advectively dominated solar wind. The section on evolution and propagation presents two approaches to the problem. One is primarily analytical and focuses on the key physical processes involved. The other is primarily numerical and illustrates the complexity of possible interactions between the CME and the ambient medium. The section on flux rope fitting reviews the accuracy and reliability of various methods. The section on shock formation considers the effect of the rapid decrease in the magnetic field and plasma density with height. Finally, in the section on particle acceleration and transport, some recent developments in the theory of diffusive particle acceleration at CME shocks are discussed. These include efforts to combine self-consistently the process of particle acceleration in the vicinity of the shock with the subsequent escape and transport of particles to distant regions.

The Arabidopsis Histidine Phosphotransfer Proteins Are Redundant Positive Regulators of Cytokinin Signaling

Abstract: Arabidopsis thaliana histidine phosphotransfer proteins (AHPs) are similar to bacterial and yeast histidine phosphotransfer proteins (HPts), which act in multistep phosphorelay signaling pathways. A phosphorelay pathway is the current model for cytokinin signaling. To assess the role of AHPs in cytokinin signaling, we isolated T-DNA insertions in the five AHP genes that are predicted to encode functional HPts and constructed multiple insertion mutants, including an ahp1,2,3,4,5 quintuple mutant. Single ahp mutants were indistinguishable from wild-type seedlings in cytokinin response assays. However, various higher-order mutants displayed reduced sensitivity to cytokinin in diverse cytokinin assays, indicating both a positive role for AHPs in cytokinin signaling and functional overlap among the AHPs. In contrast with the other four AHPs, AHP4 may play a negative role in some cytokinin responses. The quintuple ahp mutant showed various abnormalities in growth and development, including reduced fertility, increased seed size, reduced vascular development, and a shortened primary root. These data indicate that most of the AHPs are redundant, positive regulators of cytokinin signaling and affect multiple aspects of plant development.

Resolving Mismatches in U.S. Ocean Governance

Abstract: Problems in ocean resource management derive from governance, not science. Ocean zoning would replace mismatched and fragmented approaches with integrated regulatory domains.

Why Have Child Maltreatment and Child Victimization Declined

Abstract: Various forms of child maltreatment and child victimization declined as much as 40‐70% from 1993 until 2004, including sexual abuse, physical abuse, sexual assault, homicide, aggravated assault, robbery, and larceny. Other child welfare indicators also improved during the same period, including teen pregnancy, teen suicide, and children living in poverty. This article reviews a wide variety of possible explanations for these changes: demography, fertility and abortion legalization, economic prosperity, increased incarceration of offenders, increased agents of social intervention, changing social norms and practices, the dissipation of the social changes from the 1960s, and psychiatric pharmacology. Multiple factors probably contributed. In particular, economic prosperity, increasing agents of social intervention, and psychiatric pharmacology have advantages over some of the other explanations in accounting for the breadth and timing of the improvements. The worrisome stories about crimes against children that regularly fill the media have unfortunately obscured some more positive news from the statistical reports on these same offenses. Child victimization of various types has been declining since the early 1990s, in some cases declining dramatically. Facts about the Decline

Self-Reported Discrimination and Mental Health Status Among African Descendants, Mexican Americans, and Other Latinos in the New Hampshire REACH 2010 Initiative: The Added Dimension of Immigration

Abstract: Objectives. We examined whether self-reported racial discrimination was associated with mental health status and whether this association varied with race/ethnicity or immigration status.Methods. We performed secondary analysis of a community intervention conducted in 2002 and 2003 for the New Hampshire Racial and Ethnic Approaches to Community Health 2010 Initiative, surveying African descendants, Mexican Americans, and other Latinos. We assessed mental health status with the Mental Component Summary (MCS12) of the Medical Outcomes Study Short Form 12, and measured discrimination with questions related to respondents’ ability to achieve goals, discomfort/anger at treatment by others, and access to quality health care.Results. Self-reported discrimination was associated with a lower MCS12 score. Additionally, the strength of the association between self-reported health care discrimination and lower MCS12 score was strongest for African descendants, then Mexican Americans, then other Latinos. These pattern...

Supergravity microstates for BPS black holes and black rings

Abstract: We demonstrate a solution generating technique, modulo some constraints, for a large class of smooth supergravity solutions with the same asymptotic charges as a five dimensional 3-charge BPS black hole or black ring, dual to a D1/D5/P system. These solutions are characterized by a harmonic function with both positive and negative poles, which induces a geometric transition whereby singular sources have disappeared and all of the net charge at infinity is sourced by fluxes through two-cycles joining the poles of the harmonic function.

Condition and fate of logged forests in the Brazilian Amazon.

Abstract: The long-term viability of a forest industry in the Amazon region of Brazil depends on the maintenance of adequate timber volume and growth in healthy forests. Using extensive high-resolution satellite analyses, we studied the forest damage caused by recent logging operations and the likelihood that logged forests would be cleared within 4 years after timber harvest. Across 2,030,637 km2 of the Brazilian Amazon from 1999 to 2004, at least 76% of all harvest practices resulted in high levels of canopy damage sufficient to leave forests susceptible to drought and fire. We found that 16 1% of selectively logged areas were deforested within 1 year of logging, with a subsequent annual deforestation rate of 5.4% for 4 years after timber harvests. Nearly all logging occurred within 25 km of main roads, and within that area, the probability of deforestation for a logged forest was up to four times greater than for unlogged forests. In combination, our results show that logging in the Brazilian Amazon is dominated by highly damaging operations, often followed rapidly by deforestation decades before forests can recover sufficiently to produce timber for a second harvest. Under the management regimes in effect at the time of our study in the Brazilian Amazon, selective logging would not be sustained. Brazil forest disturbance remote sensing selective logging tropical forest

Dependence of the Dissipation Range Spectrum of Interplanetary Magnetic Fluctuationson the Rate of Energy Cascade

Abstract: We investigate the nature of turbulent magnetic dissipation in the solar wind We employ a database describing the spectra of over 800 intervals of interplanetary magnetic field and solar wind measurements recorded by the ACE spacecraft at 1 AU We focus on the spectral properties of the dissipation range that forms at spacecraft frequencies ≥03 Hz and show that while the inertial range at lower frequencies displays a tightly constrained range of spectral indexes, the dissipation range exhibits a broad range of power-law indexes We show that the explanation for this variation lies with the dependence of the dissipation range spectrum on the rate of energy cascade through the inertial range such that steeper spectral forms result from greater cascade rates