PHYSICAL, OPTICAL, AND CHEMICAL PROPERTIES OF LIGHT ABSORBING AEROSOLS AND THEIR CLIMATIC IMPACTS

Aerosols are particles suspended in the atmosphere; they are emitted during natural phenomena such as dust storms, wildfires, and volcanic eruptions, and during anthropogenic activities like household wood burning, vehicles operations, and industrial productions, or they can form in the atmosphere from gas to particle partition. Aerosols impact earth’s weather and climate by absorbing and scattering the incoming solar and the outgoing earth thermal radiation and interacting with clouds. The optical properties of aerosols evolve as the chemical and physical properties vary during their residence in the atmosphere. In addition, the aerosols’ properties strongly depend on the vertical distribution in the atmosphere. Due to the dynamic and heterogenous nature of the aerosol properties, their optical characteristics are still highly uncertain and hence, it is essential to quantify their ability to absorb and scatter light. To address this knowledge gap, we studied atmospheric particles in three different regions of the world with different environmental conditions and particle compositions. To investigate the details of aerosols as a function of height, we studied how their optical properties vary vertically using a tethered balloon system at the U.S. Department of Energy Atmospheric Radiation Measurement Southern Great Plains site in Oklahoma. We also estimated the top of the atmosphere radiative forcing using Lorentz-Mie simulations and the Santa Barbara Disort Atmospheric Radiative Transfer (SBDART) model. In a second study, we collected aerosol samples at a mountaintop site in Italy to study aerosols transported over long ranges. In the samples, we found an abundance of tar balls which are a kind of particles often detected in biomass-burning plumes (e.g., wildfire smoke). Tar balls absorb light at shorter wavelengths falling within the particle category often referred to as brown carbon; however, the reported complex refractive indices in the literature are highly variable. Therefore, we estimated the refractive index (RI) and optical properties of single tar balls using electron energy loss spectroscopy. We also estimated their radiative forcing to understand their potential impacts on climate and weather systems. In a third study on aerosol processing in haze conditions, we used microscopy and mass spectrometry techniques to observe the abundance of organosulfates formed through multiphase chemical reactions between organic and sulfate particles collected in the Indo-Gangetic region. The formation of organosulfates was recently shown to increase the light absorption by organic particles in the ultraviolet and visible spectral range. Finally, we classified aerosols based on their chemical composition and phase state which also affect the aerosol optical properties in complex manners. My thesis discusses the chemical, physical, and optical properties of atmospheric aerosols providing data that can be used in climate and weather models to reduce uncertainties and enhance their predictability skills

Molecular and physical composition of tar balls in wildfire smoke: an investigation with complementary ionisation methods and 15-Tesla FT-ICR mass spectrometry

Tar balls (TBs) are a major carbonaceous product of wildfires and other biomass-burning events that often exceed soot or other elemental forms of carbon in number and mass. Being a recalcitrant fraction of organic carbon, TBs are capable of long-range atmospheric transport, and thus, exert influence not only in the vicinity of wildfires but also in remote regions. Here, we characterised ambient atmospheric aerosol samples with varying TB number fractions collected downwind of Pacific Northwest wildfires using a 15-Tesla Fourier transform-ion cyclotron resonance mass spectrometer (15-T FT-ICR MS). Relative to non-TB aerosol, we found 2006 and 851 molecular formulae exclusively in TB-rich aerosol using laser desorption ionisation (LDI) of samples directly from an aerosol-loaded substrate and electrospray ionisation (ESI) of ACN-extracted aerosol, respectively. Elemental composition from LDI/15-T FT-ICR MS revealed TBs to be abundant in molecular species of low volatility and high viscosity, providing molecular detail that was consistent with key climate and air quality-related properties of TBs. Our findings demonstrate that the TB-specific molecular composition obtained from (−)LDI/15-T FT-ICR MS not only complements (−)ESI analyses, but provides a more apt reflection of the physical properties of TBs as well. We provide proof-of-concept evidence for the potential value of using LDI/15-T FT-ICR MS in routine OA analyses, specifically smoke samples rich in refractory OA, and improve the representation of OA in atmospheric and climate modelling studies that aim to fully understand its impact and occurrence

Outcome and renal function following salvage surgery for bilateral Wilms tumor: a single-institution experience

Objective: The aim of this study was to determine the surgical outcomes and renal function following salvage surgery for bilateral Wilms tumor (BWT). Summary background data The challenge for the surgeon treating BWT lies in striking a fine balance between renal preservation and oncological clearance.Methods: This is a retrospective review of medical records in a tertiary care hospital in India. Nine children with BWT who presented between 2005 and 2015 were reviewed and followed up through telephone. Survival rates were calculated using the Kaplan–Meier method. A P value of less than 0.05 was considered statistically significant.Results: Seven (78%) of nine children were boys and two (22%) were syndromic. Six (67%) children presented at less than 1 year of age. Eight (89%) children presented with an abdominal mass. There were no metastases at presentation. All children underwent trucut biopsy and neoadjuvant chemotherapy. Six children underwent surgery: four underwent bilateral nephron sparing surgery (NSS) and two underwent unilateral nephrectomy with contralateral NSS. Tumor recurred in two children. The mean follow-up was 38 months (range: 5–108 months). Creatinine clearance (CrCl) improved postoperatively in all children. Postoperative hypertension was transient and resolved with improvement in CrCl.Conclusion: Children with BWT in the Indian subcontinent may be younger than those in the rest of the world. NSS yields good outcomes even for recurrences. Postoperative hypertension is transient in the majority of patients and correlated with improvement in CrCl. Prognosis is related to operability and syndromic association.Keywords: bilateral Wilms, creatinine clearance, hypertension, nephron sparing surger

Docosatetraenoyl LPA is elevated in exhaled breath condensate in idiopathic pulmonary fibrosis

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease with no effective medical therapies. Recent research has focused on identifying the biological processes essential to the development and progression of fibrosis, and on the mediators driving these processes. Lysophosphatidic acid (LPA), a biologically active lysophospholipid, is one such mediator. LPA has been found to be elevated in bronchoalveolar lavage (BAL) fluid of IPF patients, and through interaction with its cell surface receptors, it has been shown to drive multiple biological processes implicated in the development of IPF. Accordingly, the first clinical trial of an LPA receptor antagonist in IPF has recently been initiated. In addition to being a therapeutic target, LPA also has potential to be a biomarker for IPF. There is increasing interest in exhaled breath condensate (EBC) analysis as a non-invasive method for biomarker detection in lung diseases, but to what extent LPA is present in EBC is not known. Methods: In this study, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to assess for the presence of LPA in the EBC and plasma from 11 IPF subjects and 11 controls. Results: A total of 9 different LPA species were detectable in EBC. Of these, docosatetraenoyl (22:4) LPA was significantly elevated in the EBC of IPF subjects when compared to controls (9.18 pM vs. 0.34 pM; p = 0.001). A total of 13 different LPA species were detectable in the plasma, but in contrast to the EBC, there were no statistically significant differences in plasma LPA species between IPF subjects and controls. Conclusions: These results demonstrate that multiple LPA species are detectable in EBC, and that 22:4 LPA levels are elevated in the EBC of IPF patients. Further research is needed to determine the significance of this elevation of 22:4 LPA in IPF EBC, as well as its potential to serve as a biomarker for disease severity and/or progression

Serum Amyloid P Therapeutically Attenuates Murine Bleomycin-Induced Pulmonary Fibrosis via Its Effects on Macrophages

Macrophages promote tissue remodeling but few mechanisms exist to modulate their activity during tissue fibrosis. Serum amyloid P (SAP), a member of the pentraxin family of proteins, signals through Fcγ receptors which are known to affect macrophage activation. We determined that IPF/UIP patients have increased protein levels of several alternatively activated pro-fibrotic (M2) macrophage-associated proteins in the lung and monocytes from these patients show skewing towards an M2 macrophage phenotype. SAP therapeutically inhibits established bleomycin-induced pulmonary fibrosis, when administered systemically or locally to the lungs. The reduction in aberrant collagen deposition was associated with a reduction in M2 macrophages in the lung and increased IP10/CXCL10. These data highlight the role of macrophages in fibrotic lung disease, and demonstrate a therapeutic action of SAP on macrophages which may extend to many fibrotic indications caused by over-exuberant pro-fibrotic macrophage responses

Predicted distribution of the yellow-throated marten Martes flavigula (Mammalia: Carnivora: Mustelidae) on Borneo

The yellow-throated marten Martes flavigula is a wide-ranging species across much of Asia. It is active mainly during the day, is semi-arboreal and has an omnivorous diet. On Borneo, it has a wide elevation range, from coastal lowland to lower montane habitat of 1700 m a.s.l. Records from camera-trapping and other wildlife surveys imply a widespread distribution, but the species is encountered less frequently than in many other parts of its global range. We collected a total of 195 occurrence records from all political units of Borneo except South Kalimantan. To reduce possibly confounding effects of sampling bias on habitat suitability we used 56 records in a Balanced Model and 94 records in a Spatial Filtering Model. Respondents’ opinions on habitat preference showed large variation, except for lowland and upland dipterocarp forests, which were consistently perceived as highly suitable; disturbed areas such as burnt forests and bare areas were perceived to be less favourable. The habitat suitability model predicted that the yellow-throated marten is widespread within Borneo, likely to occur in mosaics of lowland and upland forests, including old plantations and active logging areas; but unlikely to use young plantations and crops, perhaps including oil palm plantations. The effects of logging on yellow-throated marten are not well understood, yet the species’s population size on Borneo will depend on how tree plantations and logging concessions are managed and harvested. More surveys above about 1200 m a.s.l., where information is still limited, would enable more confident habitat assessments. Further research could determine if the Bornean subspecies, M. f. saba, could be a cryptic species

Predicted distribution of the Sunda clouded leopard Neofelis diardi (Mammalia: Carnivora: Felidae) on Borneo

The Sunda clouded leopard Neofelis diardi is a medium sized (15–25 kg) cat, found only on the Sundaic islands of Borneo and Sumatra. In recent years intensive camera-trapping surveys in Borneo have begun to shed light on the habitat associations and basic ecology of this elusive wild cat, but its distribution on an island-wide scale remains very poorly known. Such information is an essential element in the assessment of the Sunda clouded leopard’s conservation status and in the development of conservation action. In this paper we use MaxEnt niche distribution modelling to make predictions regarding the current distribution of this cat on Borneo. We collected a total of 259 occurrence records for the Sunda clouded leopard, stemming from all Bornean regions apart from Brunei and South Kalimantan, of which 48 (Balanced Model) or 94 (Spatial Filtering Model) were used in our modelling. Our habitat suitability model suggests that this species has a widespread distribution over a large contiguous portion of Borneo. The only exception is South Kalimantan, which is predicted largely to comprise unsuitable habitat. The predicted distribution closely follows the current distribution of little-encroached forest on Borneo (including selectively logged and unlogged areas). The species is notably predicted to be absent from the extensive areas of oil palm plantation, particularly in much of the low-lying coastal land. The predicted range encompasses a large proportion of the existing and proposed protected area network on Borneo. We highlight the priority areas for the conservation of the Sunda clouded leopard in Borneo based on our predicted distribution

Fibrocytes in Human Lung Fibrosis

Idiopathic Pulmonary Fibrosis (IPF) is a rapidly progressing interstitial lung disease (ILD) with an unclear etiology and poorly understood pathogenesis. IPF has no known curative treatment and a grim prognosis. One emerging area of interest in the field of fibrosing diseases is the role that bone marrow-derived cells, specifically fibrocytes, play in lung repair and remodeling. Derived from circulating CD14+ progenitors in the peripheral blood, these cells are identified by CD45 and pro-Collagen I co-expression. There exist scant data regarding fibrocytes derived from the peripheral blood in patients with pulmonary fibrosis. We hypothesized that (1) fibrocyte levels in the peripheral blood of patients with IPF would be greater than in patients with non-specific interstitial pneumonia (NSIP), the second most common type of ILD; (2) intrapulmonary fibrocyte levels would vary significantly between patients with IPF and non-IPF pathology; and (3) plasma from subjects with high fibrocyte levels would reveal a profile of immunomediators differing from that of patients with lower fibrocyte levels, regardless of disease state. Peripheral blood from patients with IPF (n=16), NSIP (n=7), and age-matched healthy controls (n=15) was collected, their peripheral blood mononuclear cells (PBMCs) isolated by Ficoll separation, and their plasma stored for proteomic analysis. PBMCs and lung tissue digests from patients with fibrotic lung disease (n=9) or normal controls (n=3) were then co-stained for intracellular pro-Collagen I and CD45. Plasma underwent multi-analyte ELISA for a battery of immunologic targets. We found that patients with IPF had elevated fibrocytes as percentage of PBMCs (2.74±2.12%) when compared to NSIP (0.88±0.43%) and healthy controls (0.94±0.84%), as measured by flow cytometry for CD45 and pro-Collagen I co-expression (p \u3c 0.05 NSIP vs. IPF). Furthermore, within the IPF group, fibrocyte levels varied with disease severity (p \u3c 0.05). Interestingly, while lung tissue from patients with active fibrosing pulmonary processes contained elevated fibrocyte levels (3.97±2.7%) when compared with normal human lung tissue (1.04±0.43%, p=0.11), there was no difference between IPF and non-IPF pathology. Lastly, plasma from patients with higher fibrocytes as percentages of PBMCs revealed distinct immune mediator patterns. Specifically, patients with elevated fibrocytes had higher plasma levels of IL-18, IL-8, IL-10, β2-microglobulin, ICAM-1, and TIMP-1 (p \u3c 0.05). No previous study has compared fibrocyte levels in patients with IPF and NSIP. These data suggest there is a relationship between circulating fibrocytes and development of IPF. Moreover, patients with more severe IPF disease had higher levels of circulating fibrocytes, suggesting that they may be a biomarker of both disease state and severity. In addition, lungs of patients with both IPF and non-IPF fibrotic lung disease contained more fibrocytes than healthy lungs, suggesting a broader role for this cell type in the pathogenesis of ILD than previously hypothesized. Lastly, proteomic analysis suggests that elevated fibrocytes are associated with a distinct immunologic profile, but these results do not correlate with an expected dichotomy of profibrotic TH2 versus TH1 immune profiles. These findings advance our understanding of fibrocytes as they relate to fibrotic lung disease and suggest novel avenues for future investigation