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Land uses, especially harvesting and road building, are considered to be the primary cause of forest fragmentation in many parts of the world. To test this perception, we (1) quantified changes and rates of change in vegetative composition and structure within the Washburn Ranger District in northern Wisconsin using Landsat images, (2) examined changes in landscape structure, (3) assessed changes within the area of road influence (ARI), and (4) investigated changes in landscape composition and structure within the context of forest management activities. Our landscape classifications included six dominant cover types: mixed hardwood (MH), jack pine (JP), red pine (RP), mixed hardwood/conifer (MHC), non-forested bare ground (NFBG), and regenerating forest or shrub (RFS). Increases in NFBG and RFS, by 196% and 28% respectively, reflect expansion of the pine-barrens. Windthrow in the mature hardwoods during the late 1970s and jack pine budworm outbreaks during the mid-1990s correlated with decreases in those classes over the corresponding intervals. A 69% decrease in mean patch size and a 60% increase in edge density reflect increased fragmentation. An inverse relationship existed between the compositional trends of forested (excluding JP) cover types and RFS and NFBG cover types. ARI covered 8% of the landscape affecting species composition within the MH, RFS, and NFBG. Results from this study are key in assessing the links between management activities and ecological consequences and thereby facilitate adaptive management.

We propose a working framework for future studies of net carbon exchange (NCE) in disturbed landscapes at broad spatial scales based on the central idea that landscape-level NCE is determined by the land mosaic, including its age structure. Within this framework, we argue that the area-of-edge-influence (AEI), which is prevalent in many disturbed, fragmented landscapes, should constitute a distinct ecosystem type since numerous studies have indicated unique ecological properties within these areas. We present and justify four working hypotheses currently being tested in northern Wisconsin, based on this framework: (1) the area of an ecosystem that is influenced by structural edges (e.g., AEI) has NCE that is significantly different from the ecosystem interior; (2) age structure and composition of an ecosystem play critical roles in determining the ecosystem's contribution to the cumulative net ecosystem production (NEP) of the landscape mosaic; (3) the relative importance of different structural and biophysical controls of carbon exchange is ecosystem dependent; and (4) the frequency and intensity of disturbances in time and space control the cumulative NCE of the land mosaic through alteration of ecosystems that vary in age, structure, physical environment, and interactions. In addition, we describe five different research approaches to quantify NCE at broad scales, including biometric estimations, ecophysiological methods, micrometeorological methods, applications of remote sensing and GIS, and ecosystem models.

Assessing leaf level processes in the context of other hierarchical levels (e.g., whole-plant, canopy, species, and landscape) is a current focus of ecophysiologists, and a discipline requiring additional research. The primary study objective was to examine foliar responses to light gradients (i.e., photosynthetically active radiation, PAR) across different species, age classes, and vertical positions in two landscapes: the northern deciduous forests of Wisconsin (CNF) and the Ozark highlands of southeastern Missouri (Ozarks). We measured the photosynthetic response of several light curve characteristics (e.g., maximum photosynthetic rate (Amax), stomatal conductance at Amax (gsmax), apparent quantum yield ( ), and compensation point (Γ), and dark respiration rate (RD)) changes in microclimate (e.g., vapor pressure deficit (VPD), temperature, and fraction of PAR intercepted (fPAR)), leaf (e.g., SPAD chlorophyll concentration, (SCL)), and canopy characteristics (e.g., canopy openness) of ten tree species in two climatically different landscapes. Species include bigtooth aspen, paper birch, red oak, red maple and sugar maple (CNF) and shortleaf pine, hickory, scarlet, black, and white oaks (Ozarks). Three stand age classes (i.e., young, intermediate, and mature) were measured for all species in CNF. (Abstract shortened by UMI.)

Background. Variant influenza virus infections are rare but may have pandemic potential if person-to-person transmission is efficient. We describe the epidemiology of a multistate outbreak of an influenza A(H3N2) variant virus (H3N2v) first identified in 2011. Methods. We identified laboratory-confirmed cases of H3N2v and used a standard case report form to characterize illness and exposures. We considered illness to result from person-to-person H3N2v transmission if swine contact was not identified within 4 days prior to illness onset. Results. From 9 July to 7 September 2012, we identified 306 cases of H3N2v in 10 states. The median age of all patients was 7 years. Commonly reported signs and symptoms included fever (98%), cough (85%), and fatigue (83%). Sixteen patients (5.2%) were hospitalized, and 1 fatal case was identified. The majority of those infected reported agricultural fair attendance (93%) and/or contact with swine (95%) prior to illness. We identified 15 cases of possible person-to-person transmission of H3N2v. Viruses recovered from patients were 93%–100% identical and similar to viruses recovered from previous cases of H3N2v. All H3N2v viruses examined were susceptible to oseltamivir and zanamivir and resistant to adamantane antiviral medications. Conclusions. In a large outbreak of variant influenza, the majority of infected persons reported exposures, suggesting that swine contact at an agricultural fair was a risk for H3N2v infection. We identified limited person-to-person H3N2v virus transmission, but found no evidence of efficient or sustained person-to-person transmission. Fair managers and attendees should be aware of the risk of swine-to-human transmission of influenza viruses in these settings.

Early influenza activity during the 2012-13 season enabled estimation of the unadjusted effectiveness of the seasonal influenza vaccine. This report presents updated adjusted estimates based on 2,697 children and adults enrolled in the U.S. Influenza Vaccine Effectiveness (Flu VE) Network during December 3, 2012-January 19, 2013. During this period, overall vaccine effectiveness (VE) (adjusted for age, site, race/ethnicity, self-rated health, and days from illness onset to enrollment) against influenza A and B virus infections associated with medically attended acute respiratory illness was 56%, similar to the earlier interim estimate (62%). VE was estimated as 47% against influenza A (H3N2) virus infections and 67% against B virus infections. When stratified by age group, the point estimates for VE against influenza A (H3N2) and B infections were largely consistent across age groups, with the exception that lower VE against influenza A (H3N2) was observed among adults aged ≥65 years. These adjusted VE estimates indicate that vaccination with the 2012-13 influenza season vaccine reduced the risk for outpatient medical visits resulting from influenza by approximately one half to two thirds for most persons, although VE was lower and not statistically significant among older adults. Antiviral medications should be used as recommended for treatment of suspected influenza in certain patients, including those aged ≥65 years, regardless of their influenza vaccination status.

In the United States, annual vaccination against seasonal influenza is recommended for all persons aged ≥6 months. Each season since 2004-05, CDC has estimated the effectiveness of seasonal influenza vaccine to prevent influenza-associated, medically attended acute respiratory infection (ARI). This season, early data from 1,155 children and adults with ARI enrolled during December 3, 2012-January 2, 2013 were used to estimate the overall effectiveness of seasonal influenza vaccine for preventing laboratory-confirmed influenza virus infection associated with medically attended ARI. After adjustment for study site, but not for other factors, the estimated vaccine effectiveness (VE) was 62% (95% confidence intervals [CIs] = 51%-71%). This interim estimate indicates moderate effectiveness, and is similar to a summary VE estimate from a meta-analysis of randomized controlled clinical trial data; final estimates likely will differ slightly. As of January 11, 2013, 24 states and New York City were reporting high levels of influenza-like illness, 16 states were reporting moderate levels, five states were reporting low levels, and one state was reporting minimal levels. CDC and the Advisory Committee on Immunization Practices routinely recommend that annual influenza vaccination efforts continue as long as influenza viruses are circulating. Persons aged ≥6 months who have not yet been vaccinated this season should be vaccinated. However, these early VE estimates underscore that some vaccinated persons will become infected with influenza; therefore, antiviral medications should be used as recommended for treatment in patients, regardless of vaccination status. In addition, these results highlight the importance of continued efforts to develop more effective vaccines.