Using ICESat's Geoscience Laser Altimeter System (GLAS) to assess large-scale forest disturbance caused by hurricane Katrina

In 2005, hurricane Katrina resulted in a large disturbance to U.S. forests. Recent estimates of damage from hurricane Katrina have relied primarily on optical remote sensing and field data. This paper is the first large-scale study to use satellite-based lidar data to quantify changes in forest structure from that event. GLAS data for the years prior to and following hurricane Katrina were compared to wind speed, forest cover, and damage data to assess the adequacy of sensor sampling, and to estimate changes in Mean Canopy Height (MCH) over all areas that experienced tropical force winds and greater. Statistically significant decreases in MCH post-Katrina were found to increase with wind intensity: Tropical Storm ?MCH = − 0.5 m, Category 1 ?MCH = − 2 m, and Category 2 ?MCH = − 4 m. A strong relationship was also found between changes in non-photosynthetic vegetation (?NPV), a metric previously shown to be related to storm damage, and post-storm MCH. The season of data acquisition was shown to influence calculations of MCH and MCH loss, but did not preclude the detection of major large-scale patterns of damage. Results from this study show promise for using space-borne lidar for large-scale assessments of forest disturbance, and highlight the need for future data on vegetation structure from space.     

Codelivery of NOD2 and TLR9 Ligands via Nanoengineered Protein Antigen Particles for Improving and Tuning Immune Responses

Vaccine adjuvants that can induce robust protective immunity are highly sought after for the development of safer and more effective vaccines. Vaccine formulation parameters that govern efficacy are still far from clear, such as the diverse impacts of codelivering agonist molecules for innate cell receptors (e.g., pattern recognition receptors). In this study, a mesoporous silica‐templating approach is used to fabricate protein antigen (ovalbumin) particles covalently functionalized with agonists for NOD‐like receptor 2 (NOD2) and Toll‐like receptor 9 (TLR9). Particle‐induced combinatorial NOD2/TLR9 signaling results in synergistic inflammatory cytokine secretion by mouse macrophages (RAW 264.7). Administration of NOD2/TLR9 particles in mice results in adaptive immune responses that are both quantitatively and qualitatively different than those resulting from administration of particles conjugated with either NOD2 or TLR9 agonists alone. While delivery of NOD2 agonists alone activates T helper 2 (Th2)‐type responses (and no CD8+ T cell activation) and delivery of TLR9 agonists alone activates CD8+ T cell and T helper 1 (Th1)‐type responses, codelivery of NOD2 and TLR9 agonists enhances Th1‐type responses and abrogates CD8+ T cell activation. The results illustrate that in the particle‐based system, NOD2 activation plays different roles in polarizing adaptive immune responses depending on coactivation of TLR9.     

Employee job attitudes and organizational characteristics as predictors of cyberloafing

Cyberloafing is the personal use of the Internet by employees while at work. The purpose of this study is to examine whether employee job attitudes, organizational characteristics, attitudes towards cyberloafing, and other non-Internet loafing behaviors serve as antecedents to cyberloafing behaviors. We hypothesize that the employee job attitudes of job involvement and intrinsic involvement are related to cyberloafing. In addition, we hypothesize that organizational characteristics including the perceived cyberloafing of one’s coworkers and managerial support for internet usage are related to cyberloafing. We also hypothesize that attitudes towards cyberloafing and the extent to which employees participate in non-Internet loafing behaviors (e.g., talking with coworkers, running personal errands) will both be related to cyberloafing. One hundred and forty-three working professional from a variety of industries were surveyed regarding their Internet usage at work. As hypothesized, the employee job attitudes of job involvement and intrinsic involvement were negatively related to cyberloafing. Also as predicted, the organizational characteristics of the perceived cyberloafing of one’s coworkers and managerial support for internet usage were positively related to cyberloafing. Finally, results showed that attitudes towards cyberloafing and participation in non-Internet loafing behaviors were positively related to cyberloafing. Implications for both organizations and employees are discussed.     

Amending soil with used cooking oil to reduce nitrogen losses after cole crop harvest: a 15N study

After cole crop harvest, over 400 kg N ha^?1 may remain in the field as crop residues and soil mineral N. Thus, methods to reduce potential post-harvest N losses are needed. Urea with 5 % ¹⁵N excess was incorporated in mini-plots to produce ¹⁵N enriched broccoli (Brassica olecerea var italica L.). The fate of above-ground crop residue-derived N (¹⁵N_{residue-above}) and below-ground residual fertilizer or root biomass N (¹⁵N_{residue-below}) were studied from broccoli harvest (Aug and Sept 2011) to spring wheat (Triticum durum L.) harvest (July 2012), with and without an amendment of used cooking oil. The ¹⁵N_{residue-below} remained mostly as organic N, was not influenced by the amendment, and was resistant to post-harvest losses. With the oil amendment, soil mineral ¹⁵N_{residue-above} was reduced by 19 kg ha^?1 and microbial biomass ¹⁵N_{residue-above} was increased by 21 kg ha^?1 2 weeks after broccoli harvest, indicating immobilization of ¹⁵N_{residue-above} and reduced potential N losses. At spring wheat harvest, amended soil had greater total, organic, and mineral ¹⁵N_{residue-above} compared to the unamended control, by 44, 43, and 0.75 kg ha^?1, respectively. The amendment increased the recovery of ¹⁵N_{residue-above} in the soil total N pool by 209 % at spring wheat harvest, and it did not affect spring wheat yields or plant ¹⁵N_{residue-above} content. It is possible that the amendment facilitated the incorporation of ¹⁵N_{residue-above} into organic compounds, which were less susceptible to losses. Growers should consider applying used cooking oil at harvest to minimize potential N losses and to increase the soil organic N fraction.     

Impact of Fluid Flow Shear Stress on Osteoblast Differentiation and Cross-Talk with Articular Chondrocytes

Bone cells, in particular osteoblasts, are capable of communication with each other during bone growth and homeostasis. More recently it has become clear that they also communicate with other cell-types; including chondrocytes in articular cartilage. One way that this process is facilitated is by interstitial fluid movement within the pericellular and extracellular matrices. This stimulus is also an important mechanical signal in skeletal tissues, and is known to generate shear stresses at the micron-scale (known as fluid flow shear stresses (FFSS)). The primary aim of this study was to develop and characterize an in vitro bone–cartilage crosstalk system, to examine the effect of FFSS on these cell types. Specifically, we evaluated the response of osteoblasts and chondrocytes to FFSS and the effect of FFSS-induced soluble factors from the former, on the latter. This system will ultimately be used to help us understand the role of subchondral bone damage in articular cartilage degeneration. We also carried out a comparison of responses between cell lines and primary murine cells in this work. Our findings demonstrate that primary cells produce a more reliable and reproducible response to FFSS. Furthermore we found that at lower magnitudes , direct FFSS produces anabolic responses in both chondrocytes and osteoblasts, whereas higher levels produce more catabolic responses. Finally we show that exposure to osteoblast-derived factors in conditioned media experiments produced similarly catabolic changes in primary chondrocytes.     

Sex-Specific Effects of Plastic Caging in Murine Viral Myocarditis

Background: Myocarditis is an inflammatory heart disease caused by viral infections that can lead to heart failure, and occurs more often in men than women. Since animal studies have shown that myocarditis is influenced by sex hormones, we hypothesized that endocrine disruptors, which interfere with natural hormones, may play a role in the progression of the disease. The human population is exposed to the endocrine disruptor bisphenol A (BPA) from plastics, such as water bottles and plastic food containers. Methods: Male and female adult BALB/c mice were housed in plastic versus glass caging, or exposed to BPA in drinking water versus control water. Myocarditis was induced with coxsackievirus B3 on day 0, and the endpoints were assessed on day 10 post infection. Results: We found that male BALB/c mice that were exposed to plastic caging had increased myocarditis due to complement activation and elevated numbers of macrophages and neutrophils, whereas females had elevated mast cell activation and fibrosis. Conclusions: These findings show that housing mice in traditional plastic caging increases viral myocarditis in males and females, but using sex-specific immune mechanisms.     

Graduate Student Literature Review: Challenges and opportunities for human resource management on dairy farms

Dairy farms are increasing in size and moving from family to external labor. As such, dairy farmers now have the responsibilities of a human resource manager in addition to caring for their animals. The objective of this paper was to review literature in 5 areas of human resource management of a dairy farm: (1) professional accreditation and professional development, (2) extension activities, (3) the role of the advisor, (4) standard operating procedures, and (5) employee training. Although there has been an increase in research in this area in recent years, this review identified numerous areas for future research, including the relationships between farmers and their advisors and employees, and the role of standard operating procedures on dairy farms. In addition, we suggest that future studies could benefit from increased use of participatory research methods.     

Acid- and base-catalyzed epoxy-phenol thermosets from catechol,resorcinol and hydroquinone: A structure–property study

In order to better understand the design rules of epoxy–phenol thermosets we will report on the chemistry and (thermo)mechanical properties of cured epoxy–phenol thermoset films. Ortho-, meta- and para-isomers of dihydroxybenzene (DHB) were reacted with the diglycidyl ether of bisphenol A (DGEBA) in the presence of an acid catalyst or triphenylphosphine (PPh₃). The glass transition temperatures (T_g) of the cross-linked films decreases in the order of meta- (T_g = 115°C) > ortho- (T_g = 102°C) > para-DHB (T_g = 96°C) as measured by differential scanning calorimetry. Uniaxial tensile testing of cross-linked films showed excellent stress–strain behavior. The average ultimate strength values ranged from 65 to 82 MPa and the average values of the strain-at-break ranged from 4.8% to 6.9% at 25°C for all cross-linked films. When a PPh₃ was used, the network properties were profoundly different. The base catalyzed thermoset of DGEBA and meta-DHB shows a T_g of 85°C, which is 30°C lower than the T_g of the acid-catalyzed analog. Tensile films appear to be more ductile, as they exhibit a strain-at-break of 20%. The results of this study confirm that simple dihydroxybenzene hardeners can be used to prepare cross-linked films with excellent thermomechanical properties.     

Promotion of lung adenocarcinoma following inhalation exposure to multi-walled carbon nanotubes

Background

Engineered carbon nanotubes are currently used in many consumer and industrial products such as paints, sunscreens, cosmetics, toiletries, electronic processes and industrial lubricants. Carbon nanotubes are among the more widely used nanoparticles and come in two major commercial forms, single-walled carbon nanotubes (SWCNT) and the more rigid, multi-walled carbon nanotubes (MWCNT). The low density and small size of these particles makes respiratory exposures likely. Many of the potential health hazards have not been investigated, including their potential for carcinogenicity. We, therefore, utilized a two stage initiation/promotion protocol to determine whether inhaled MWCNT act as a complete carcinogen and/or promote the growth of cells with existing DNA damage. Six week old, male, B6C3F1 mice received a single intraperitoneal (ip) injection of either the initiator methylcholanthrene(MCA, 10 μg/g BW, i.p.), or vehicle (corn oil). One week after i.p. injections, mice were exposed by inhalation to MWCNT (5 mg/m³, 5 hours/day, 5 days/week) or filtered air (controls) for a total of 15 days. At 17 months post-exposure, mice were euthanized and examined for lung tumor formation.

Results

Twenty-three percent of the filtered air controls, 26.5% of the MWCNT-exposed, and 51.9% of the MCA-exposed mice, had lung bronchiolo-alveolar adenomas and lung adenocarcinomas. The average number of tumors per mouse was 0.25, 0.81 and 0.38 respectively. By contrast, 90.5% of the mice which received MCA followed by MWCNT had bronchiolo-alveolar adenomas and adenocarcinomas with an average of 2.9 tumors per mouse 17months after exposure. Indeed, 62% of the mice exposed to MCA followed by MWCNT had bronchiolo-alveolar adenocarcinomas compared to 13% of the mice that received filtered air, 22% of the MCA-exposed, or 14% of the MWCNT-exposed. Mice with early morbidity resulting in euthanasia had the highest rate of metastatic disease. Three mice exposed to both MCA and MWCNT that were euthanized early had lung adenocarcinoma with evidence of metastasis (5.5%). Five mice (9%) exposed to MCA and MWCNT and 1 (1.6%) exposed to MCA developed serosal tumors morphologically consistent with sarcomatous mesotheliomas, whereas mice administered MWCNT or air alone did not develop similar neoplasms.

Conclusions

These data demonstrate that some MWCNT exposures promote the growth and neoplastic progression of initiated lung cells in B6C3F1 mice. In this study, the mouse MWCNT lung burden of 31.2 μg/mouse approximates feasible human occupational exposures. Therefore, the results of this study indicate that caution should be used to limit human exposures to MWCNT.     

E-empowerment: Empowerment by the Internet

This article focuses on the concept of empowerment and the ways in which the Internet is being utilized as an empowering tool. This analysis ranges from the personal to the global levels and the consequences of that empowerment are also discussed. We propose a four-level model that serves to explain what we term E-empowerment and the effects that can be observed at each of the four levels, ranging from (1) the personal; (2) the interpersonal; (3) group; and (4) citizenship. The potential for future development of E-empowerment is also discussed.