Uptake of nitrate and sulfate on dust aerosols during TRACE-P

Aerosol data collected near Asia on the DC-8 aircraft platform during TRACE-P has been examined for evidence of uptake of NO3− and SO4= on dust surfaces. Data is compared between a sector where dust was predominant and a sector where dust was less of an influence. Coincident with dust were higher mixing ratios of anthropogenic pollutants. HNO3, SO2, and CO were higher in the dust sector than the nondust sector by factors of 2.7, 6.2, and 1.5, respectively. The colocation of dust and pollution sources allowed for the uptake of NO3−and nss-SO4= on the coarse dust aerosols, increasing the mixing ratios of these particulates by factors of 5.7 and 2.6 on average. There was sufficient nss-SO4= to take up all of the NH4+present, with enough excess nss-SO4= to also react with dust CaCO3. This suggests that the enhanced NO3− was not in fine mode NH4NO3. Particulate NO3− (p-NO3−) constituted 54% of the total NO3− (t-NO3−) on average, reaching a maximum of 72% in the dust sector. In the nondust sector, p-NO3− contributed 37% to t-NO3−, likely due to the abundance of sea salts there. In two other sectors where the influence of dust and sea salt were minimal, p-NO3−accounted for \u3c15% of t-NO3−

Unusual Digital Patterns In EPS: Evidence On The Association Between Earnings Management And Company Characteristics

Prior studies (Thomas, 1989; Das and Zhang, 2003) provide evidence of earnings manipulation to achieve cognitive reference points in EPS.  The current study extends this line of research by examining the relation between unusual digital patterns in the right EPS position and specific firm characteristics.  Results suggest that the propensity to manage earnings to effect desired EPS results is particularly associated with company size and to a lesser degree with operating performance and the level of debt leverage employed

Morphoproteomic profiling of the mammalian target of rapamycin (mTOR) signaling pathway in desmoplastic small round cell tumor (EWS/WT1), Ewing's sarcoma (EWS/FLI1) and Wilms' tumor(WT1).

BackgroundDesmoplastic small round cell tumor (DSRCT) is a rare sarcoma in adolescents and young adults. The hallmark of this disease is a EWS-WT1 translocation resulting from apposition of the Ewing's sarcoma (EWS) gene with the Wilms' tumor (WT1) gene. We performed morphoproteomic profiling of DSRCT (EWS-WT1), Ewing's sarcoma (EWS-FLI1) and Wilms' tumor (WT1) to better understand the signaling pathways for selecting future targeted therapies.MethodologyThis pilot study assessed patients with DSRCT, Wilms' tumor and Ewing's sarcoma. Morphoproteomics and immunohistochemical probes were applied to detect: p-mTOR (Ser2448); p-Akt (Ser473); p-ERK1/2 (Thr202/Tyr204); p-STAT3 (Tyr 705); and cell cycle-related analytes along with their negative controls.Principal findingsIn DSRCT the PI3K/Akt/mTOR pathway is constitutively activated by p-Akt (Ser 473) expression in the nuclear compartment of the tumor cells and p-mTOR phosphorylated on Ser 2448, suggesting mTORC2 (rictor+mTOR) as the dominant form. Ewing's sarcoma had upregulated p-Akt and p-mTOR, predominantly mTORC2. In Wilm's tumor, the mTOR pathway is also activated with most tumor cells moderately expressing p-mTOR (Ser 2448) in plasmalemmal and cytoplasmic compartments. This coincides with the constitutive activation of one of the downstream effectors of the mTORC1 signaling pathway, namely p-p70S6K (Thr 389). There was constitutive activation of the Ras/Raf/ERK pathway p-ERK 1/2 (Thr202/Tyr204) expression in the Wilms tumor and metastatic Ewing's sarcoma, but not in the DSRCT.ConclusionMORPHOPROTEOMIC TUMOR ANALYSES REVEALED CONSTITUTIVE ACTIVATION OF THE MTOR PATHWAY AS EVIDENCED BY: (a) expression of phosphorylated (p)-mTOR, p-p70S6K; (b) mTORC 2 in EWS and DSRCT; (c) ERK signaling was seen in the advanced setting indicating these as resistance pathways to IGF1R related therapies. This is the first morphoproteomic study of such pathways in these rare malignancies and may have potential therapeutic implications. Further study using morphoproteomic assessments of these tumors are warranted

Unusual Digital Patterns in EPS: Evidence On the Association Between Earnings Management and Company Characteristics

Prior studies (Thomas, 1989; Das and Zhang, 2003) provide evidence of earnings manipulation to achieve cognitive reference points in EPS. The current study extends this line of research by examining the relation between unusual digital patterns in the right EPS position and specific firm characteristics. Results suggest that the propensity to manage earnings to effect desired EPS results is particularly associated with company size and to a lesser degree with operating performance and the level of debt leverage employed

Preliminary Evidence Of SFAS No. 130's Effect On Gains Trading In The Insurance Industry

Gains trading represents a form of earnings management whereby appreciated marketable securities are sold at a gain while those with a loss are retained. By not requiring unrealized gains and losses on available-for-sale securities to flow through income, SFAS No. 115 failed to close the door on this type of earnings management. With SFAS No. 130, however, these unrealized gains and losses must now be reported prominently in a financial statement as a component of comprehensive income. By examining the level of gains trading for a sample of companies in the insurance industry both before and after the implementation of SFAS No. 130, the current study provides evidence suggesting that this form of earnings management subsided subsequent to the adoption of SFAS No. 130

Chemical and physical properties of bulk aerosols within four sectors observed during TRACE-P

Chemical and physical aerosol data collected on the DC-8 during TRACE-P were grouped into four sectors based on back trajectories. The four sectors represent long-range transport from the west (WSW), regional circulation over the western Pacific and Southeast Asia (SE Asia), polluted transport from northern Asia with substantial sea salt at low altitudes (NNW) and a substantial amount of dust (Channel). WSW has generally low mixing ratios at both middle and high altitudes, with the bulk of the aerosol mass due to non-sea-salt water-soluble inorganic species. Low altitude SE Asia also has low mean mixing ratios in general, with the majority of the aerosol mass comprised of non-sea-salts, however, soot is also relatively important in this region. NNW had the highest mean sea salt mixing ratios, with the aerosol mass at low altitudes (\u3c2 km) evenly divided between sea salts, non-sea-salts, and dust. The highest mean mixing ratios of water-soluble ions and soot were observed at the lowest altitudes (\u3c2 km) in the Channel sector. The bulk of the aerosol mass exported from Asia emanates from Channel at both low and midaltitudes, due to the prevalence of dust compared to other sectors. Number densities show enhanced fine particles for Channel and NNW, while their volume distributions are enhanced due to sea salt and dust. Low-altitude Channel exhibits the highest condensation nuclei (CN) number densities along with enhanced scattering coefficients, compared to the other sectors. At midaltitudes (2–7 km), low mean CN number densities coupled with a high proportion of nonvolatile particles (≥65%) observed in polluted sectors (Channel and NNW) are attributed to wet scavenging which removes hygroscopic CN particles. Low single scatter albedo in SE Asia reflects enhanced soot

Complementary Lenses: Using Theories of Situativity and Complexity to Understand Collaborative Learning as Systems-Level Social Activity

This article highlights possibilities for understanding challenges related to collaborative learning by bringing two complementary lenses into theoretical and empirical conversation—complexity and situativity. After presenting a theoretical comparison that characterizes complementarity between complexity and situativity in order to frame their relative contributions to a systems-level understanding of learning processes, we examine persistently unproductive social activity during a 14-session, collaborative engineering design project in a fifth-grade peer group from both perspectives. We do so in order to demonstrate the value of these complementary perspectives for understanding collaborative learning processes and to suggest different explanations of why unproductive social activity sometimes persists and possibilities for interrupting such dynamics. We thus suggest a shift from explanatory accounts of system processes to prospective processes for systems of action within social ecologies of change. Such a framework can resolve the social activity of collaborative learning around a systems-level orientation

Spectral aerosol extinction (SpEx): a new instrument for in situ ambient aerosol extinction measurements across the UV/visible wavelength range

We introduce a new instrument for the measurement of in situ ambient aerosol extinction over the 300– 700 nm wavelength range, the spectral aerosol extinction (SpEx) instrument. This measurement capability is envisioned to complement existing in situ instrumentation, allowing for simultaneous measurement of the evolution of aerosol optical, chemical, and physical characteristics in the ambient environment. In this work, a detailed description of the instrument is provided along with characterization tests performed in the laboratory. Measured spectra of NO2 and polystyrene latex spheres (PSLs) agreed well with theoretical calculations. Good agreement was also found with simultaneous aerosol extinction measurements at 450, 530, and 630 nm using CAPS PMex instruments in a series of 22 tests including nonabsorbing compounds, dusts, soot, and black and brown carbon analogs. SpEx measurements are expected to help identify the presence of ambient brown carbon due to its 300 nm lower wavelength limit compared to measurements limited to longer UV and visible wavelengths. Extinction spectra obtained with SpEx contain more information than can be conveyed by a simple power law fit (typically represented by Ångström exponents). Planned future improvements aim to lower detection limits and ruggedize the instrument for mobile operation

The impact of local sources and long-range transport on aerosol properties over the northeast U.S. region during INTEX-NA

We use data collected aboard the NASA DC-8 aircraft during the summer 2004, Intercontinental Transport and Chemical Evolution Experiment over North America (INTEX-NA) field campaign to examine the origin, composition, physical and optical properties of aerosols within air masses sampled over and downwind of the northeastern U.S. We note that aerosol concentrations within the region exhibited steep vertical gradients and significant variability in both time and space. An examination of air mass chemical signatures and backward trajectories indicates that transport from four, significantly different source regions contributed to the variability: the subtropical Atlantic Ocean (AO); the U.S. west coast and eastern Pacific (WCP); the U.S. east coast and Midwestern states (EC); and northwest Canada and Alaska (CA). AO air masses were typically confined to below 2 km altitude, exhibited low pollutant contents, contained enhanced levels of sea salt, and were typically observed when the Bermuda High strengthened. The most common air mass present in the upper troposphere, WCP air often contained weak dust and aged pollution enhances from convective input occurring over the central part of the continent. CA air exhibited enhancements in anthropogenic pollution tracers below 2 km and contained some black-carbon rich haze layers between 3 and 5 km that could be traced to forest fires burning in western Canada and Alaska. EC air was prevalent at lower elevations throughout the study area and exhibited enhanced scattering along with elevated levels of sulfate aerosols and combustion tracers. There is an overall balance between the observed cations and anions for all cases, except EC air mass below 4 km