Modeling sea ice albedo and transmittance measurements with a fully-coupled radiative transfer model.

A rigorous treatment of the sea ice medium has been incorporated in the advanced Coupled Ocean-Atmosphere Radiative Transfer (COART) model. The inherent optical properties (IOPs) of brine pockets and air bubbles over the 0.25-4.0 µm spectral region are parameterized as a function of the sea ice physical properties (temperature, salinity and density). We then test the performance of the upgraded COART model using three physically-based modeling approaches to simulate the spectral albedo and transmittance of sea ice, and compare them with measurements collected during the Impacts of Climate on the Ecosystems and Chemistry of the Arctic Pacific Environment (ICESCAPE) and the Surface Heat Budget of the Arctic Ocean (SHEBA) field campaigns. The observations are adequately simulated when at least three layers are used to represent bare ice, including a thin surface scattering layer (SSL), and two layers to represent ponded ice. Treating the SSL as a low-density ice layer yields better model-observation agreement than treating it as a snow-like layer. Sensitivity results indicate that air volume (which determines the ice density) has the largest impact on the simulated fluxes. The vertical profile of density drives the optical properties but available measurements are scarce. The approach where the scattering coefficient for the bubbles is inferred in lieu of density leads to essentially equivalent modeling results. For ponded ice, the albedo and transmittance in the visible are mainly determined by the optical properties of the ice underlying the water layer. Possible contamination from light-absorbing impurities, such as black carbon or ice algae, is also implemented in the model and is able to effectively reduce the albedo and transmittance in the visible spectrum to further improve the model-observation agreement.

Effects of Chronic Exposure to Microcystin-LR on the Gut Microbiota of Male Mice.

Increasing evidence indicates that environmental pollutants can change human gut microbiota. Microcystin-leucine arginine (MC-LR), considered a major hazard to mammals, is one of the important contaminants. However, little is known about the long-term influence of MC-LR on gut microbial communities. We aimed to investigate the effect of MC-LR on gut microbiota composition and functions by conducting a chronic exposure of male mice to MC-LR via the oral route. Using 16S rRNA gene sequencing analysis on cecum samples of mice, our results showed that significant changes of species diversity were observed in the gut microbiota of MC-LR-exposed mice. In addition, comparative analysis of the microbial communities showed that the reduction of the Actinobacteria and Saccharibacteria populations was detected in MC-LR-exposed mice. Collectively, our study highlighted the significant effects of MC-LR on the shift of gut microbial communities which could contribute to the development of metabolic syndromes.

TRIM14 promotes cell proliferation and inhibits apoptosis by suppressing PTEN in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is among the most frequent and lethal malignancies worldwide. Although great advances have been made in the treatment of CRC, prognosis remains poor. Our previous study indicated that tripartite motif-containing 14 (TRIM14) was upregulated in CRC samples. METHODS: In the current study, the association between TRIM14 and CRC was investigated. Protein expression was determined by Western blotting and immunohistochemistry. Further, the biological roles of TRIM14 in CRC cell proliferation and apoptosis were explored both in vitro and in vivo. RESULTS: We observed that increased TRIM14 expression in CRC tissues was closely related with aggressive clinicopathological characteristics and poor prognosis. TRIM14 knockdown markedly reduced proliferation and increased apoptosis in HT-29 and SW620 cells, whereas TRIM14 overexpression in LoVo cells displayed opposite results. Xenograft experiments using HT-29 cells confirmed suppression of tumor growth and induction of apoptosis upon TRIM14 knockdown in vivo. Furthermore, downregulation of TRIM14 inhibited the AKT pathway, as indicated by reduced levels of phosphorylated AKT, Bcl-2 and Cyclin D1, and elevated levels of phosphatase and tensin homology (PTEN) and p27. In addition, TRIM14 colocalized with PTEN in the cytoplasm and induced PTEN ubiquitination. Moreover, PTEN overexpression significantly inhibited pro-proliferative effects of TRIM14, indicating an involvement of PTEN/AKT signaling in mediating TRIM14 functions. CONCLUSIONS: The present data demonstrate that TRIM14 overexpression promotes CRC cell proliferation, suggesting TRIM14 as an attractive therapeutic target for CRC.

Cloud scattering impact on thermal radiative transfer and global longwave radiation.

The potential importance of longwave (LW) cloud scattering has been recognized but the actual estimate of this effect on thermal radiation varies greatly among different studies. General circulation models (GCMs) generally neglect or simplify the multiple scattering in the LW. In this study, we use a rigorous radiative transfer algorithm to explicitly consider LW multiple-scattering and apply the GCM to quantify the impact of cloud LW scattering on thermal radiation fluxes. Our study shows that the cloud scattering effect on downward thermal radiation at the surface is concentrated in the infrared atmospheric window spectrum (800-1250 cm-1). The scattering effect on the outgoing longwave radiation (OLR) is also present in the window region over low clouds but it is mainly in the far-infrared spectrum (300-600 cm-1) over high clouds. For clouds with small to moderate optical depth (τ < 10), the scattering effect on thermal fluxes shows large variation with the cloud τ and has a maximum at an optical depth of ~3. For opaque clouds, the scattering effect approaches an asymptote and is smaller and less important. The 2-stream radiative transfer scheme could have an error over 10% with an RMS error around 3.5%-4.0% in the calculated LW flux. This algorithm error of the 2-stream approximation could readily exceed the no-scattering error in the LW, and thus it is worthless to include the time-consuming computation of multiple scattering in a 2-stream radiative transfer scheme. However, the calculation error rapidly decreases as stream number increases and the RMS error in LW flux using the 4-stream scheme is under 0.3%, an accuracy sufficient for most climate studies. We implement the 4-stream discrete-ordinate algorithm in the GISS GCM and run the GCM for 20 years with and without the LW scattering effect, respectively. When cloud LW scattering is included, we find that the global annual mean OLR is reduced by 2.7 W/m2, and the downward surface flux and the net atmospheric absorption are increased by 1.6 W/m2 and 1.8 W/m2, respectively. Using one year of ISCCP clouds and running the standalone radiative transfer offline, the global annual mean non-scattering errors in OLR, surface LW downward flux and net atmospheric absorption are 3.6W/m2, -1.1 W/m2, and -2.5 W/m2, respectively. The global scattering impact of 2.7 W/m2 on the OLR is small when compared to the typical global OLR value of 240W/m2, but it is significant when compared to cloud LW radiative forcing (30W/m2) and net cloud forcing (-14W/m2). Overall, the effect of neglecting scattering on the thermal fluxes is comparable to the reported clear sky radiative effect of doubling CO2.

TRIM14 promotes colorectal cancer cell migration and invasion through the SPHK1/STAT3 pathway.

BACKGROUND: Colorectal cancer (CRC) is one of the most lethal malignancies. Tripartite Motif Containing 14 (TRIM14) is a member of TRIM family proteins, which are involved in the pathogenesis of various cancers. This study aimed to investigate TRIM14 expression in CRC tissues, and its effects on the migration and invasion of CRC cell lines. METHODS: TRIM14 mRNA expression was detected by real-time PCR analysis. Cell migration and invasion were measured by Transwell assays. Protein expression was assessed by western blot analysis. RESULTS: The expression of TRIM14 was significantly higher in CRC tissues than in matched non-cancerous tissues. TRIM14 knockdown by specific short hairpin RNA (shRNA) attenuated CRC cell migration and invasion, whereas TRIM14 overexpression caused reverse effect. Moreover, TRIM14 positively regulated the protein levels of sphingosine kinase 1 (SPHK1) and phosphorylated STAT3 (p-STAT3), as well as the mRNA and protein expression of matrix metalloproteinase 2, MMP9 and vascular endothelial growth factor, which are transcriptional targets of the STAT3 signaling pathway. Importantly, the blockage of the SPHK1/STAT3 signaling pathway by SKI-II or AG490 could reverse the TRIM14-promoted CRC cell migration and invasion. CONCLUSIONS: Our results reveal a critical role for TRIM14 in promoting migration and invasion of CRC cells, and suggest TRIM14 may serve as a potential molecular target to prevent CRC metastasis.

The effects of fibroblast growth factor-2 delivered via a Gelfoam patch on the regeneration of myringosclerotic traumatic eardrum perforations lying close to the malleus.

OBJECTIVE: We evaluated the effects of fibroblast growth factor-2 (FGF-2) delivered via a Gelfoam patch on the regeneration of myringosclerotic traumatic tympanic membrane perforations (TMPs) lying close to the malleus. STUDY DESIGN: A prospective, randomized, controlled clinical study. SETTING: A university-affiliated teaching hospital. SUBJECTS AND METHODS: We prospectively analyzed, in a randomized manner, the outcomes of treatment for traumatic TMPs constituting >25% of the tympanic membrane. The closure rates, closure times, and otorrhea rates were compared among patients treated via FGF-2-containing Gelfoam patches, Gelfoam patches alone, and observation only. RESULTS: We analyzed data from 138 patients. The perforation closure rates in the FGF-2 plus Gelfoam patch, Gelfoam patch, and observation alone groups were 97.9, 89.8, and 70.7%, respectively. Both the FGF-2 plus Gelfoam and Gelfoam alone groups exhibited significantly higher closure rates than the observational group (both p<0.05).The mean closure times were 15.7±5.1, 24.8±4.9, and 35.7±9.2days in the FGF-2 plus Gelfoam patch, Gelfoam patch alone, and observation alone groups, respectively. The FGF-2 plus Gelfoam patch group exhibited a significantly shorter closure time than the Gelfoam patch alone and observation alone groups (p<0.05). The incidences of purulent otorrhea were 14.6, 6.1, and 4.9% in the FGF-2 plus Gelfoam patch, Gelfoam patch alone, and observation alone groups, respectively. Surprisingly, 7 of 7 (100.0%) perforations associated with purulent otorrhea completely closed in the FGF-2 plus Gelfoam patch group; however, no such perforation healed in either the Gelfoam alone or observation alone group. CONCLUSIONS: FGF-2 plus Gelfoam patching significantly shortened the closure time compared to observation and Gelfoam patching alone, and it significantly improved the closure rate (compared to observation alone) of myringosclerotic perforations lying close the malleus. FGF-2 plus Gelfoam patching is a valuable, minimally invasive alternative treatment that may be readily applied to outpatient settings.

Assessment and spontaneous healing outcomes of traumatic eardrum perforation with bleeding.

OBJECTIVE: This study investigated the influence of the degree of bleeding from the remnant eardrum on the spontaneous healing of human traumatic tympanic membrane perforations (TMPs). STUDY DESIGN: A case series with chart review. SETTING: A tertiary university hospital. MATERIALS AND METHODS: The clinical records of traumatic TMP patients who met the case selection criteria were retrieved and categorized into two groups based on the documented degree of bleeding from the remnant eardrum: with and without bleeding. The demographic data and spontaneous healing outcomes (i.e., healing rate and duration) of these two TMP types were analyzed using the chi-squared test or t-test. RESULTS: One-hundred and eighty-eight cases met the inclusion criteria and were analyzed. Of these, 58.5% had perforations without bleeding and the remaining 41.5% had perforations with bleeding. The overall closure rate at the end of the 3-month follow-up period was 90.9% for perforations without bleeding and 96.2% for perforations with bleeding; the difference was not statistically significant (P>0.05). However, the average closure time differed significantly between the two groups (P<0.05): 29.4±3.7days for perforations without bleeding and 20.6±9.2days for perforations with bleeding. The closure rate was significantly different between the groups (62 vs. 15.6%, P<0.01) within 2weeks for medium-sized perforations. In total, 11 (39.3%) large-sized perforations achieved complete closure in the group with bleeding, while none of the large-sized perforations closed in the group without bleeding within 2weeks. The closure rate of medium-sized perforations was not significantly different (79.2 vs. 92%, P>0.05) between the groups without and with bleeding within 4weeks, while the closure rate of large-sized perforations was significantly different between the groups without and with bleeding (27.2 vs. 75%, P=0.0). CONCLUSION: This study shows that traumatic TMPs with bleeding significantly shortened the closure time compared to TMPs without bleeding. This finding indicates a significant correlation between the prognosis of traumatic TMPs and the degree of eardrum bleeding: severe bleeding from and a hematoma in the remnant eardrum appear to be good signs.

Development of a fast and accurate PCRTM radiative transfer model in the solar spectral region.

A fast and accurate principal component-based radiative transfer model in the solar spectral region (PCRTM-SOLAR) has been developed. The algorithm is capable of simulating reflected solar spectra in both clear sky and cloudy atmospheric conditions. Multiple scattering of the solar beam by the multilayer clouds and aerosols are calculated using a discrete ordinate radiative transfer scheme. The PCRTM-SOLAR model can be trained to simulate top-of-atmosphere radiance or reflectance spectra with spectral resolution ranging from 1 cm-1 resolution to a few nanometers. Broadband radiances or reflectance can also be calculated if desired. The current version of the PCRTM-SOLAR covers a spectral range from 300 to 2500 nm. The model is valid for solar zenith angles ranging from 0 to 80 deg, the instrument view zenith angles ranging from 0 to 70 deg, and the relative azimuthal angles ranging from 0 to 360 deg. Depending on the number of spectral channels, the speed of the current version of PCRTM-SOLAR is a few hundred to over one thousand times faster than the medium speed correlated-k option MODTRAN5. The absolute RMS error in channel radiance is smaller than 10-3 mW/cm2/sr/cm-1 and the relative error is typically less than 0.2%.

The protective role of montelukast against intestinal ischemia-reperfusion injury in rats.

Several drugs are effective in attenuating intestinal ischemia-reperfusion injury (IRI); however little is known about the effect of montelukast. Fifty rats were randomly assigned to 3 groups: model group (operation with clamping), sham group (operation without clamping), and study group (operation with clamping and 0.2, 2 and 20 mg/kg montelukast pretreatment). Intestinal ischemia-reperfusion was performed by occlusion (clamping) of the arteria mesenterica anterior for 45 min, followed by 24 h reperfusion. Intestinal IRI in the model group led to severe damage of the intestinal mucosa, liver and kidney. The Chiu scores of the intestines from the study group (2 and 20 mg/kg) were lower than that of the model group. Intestinal IRI induced a marked increase in CysLTR1, Caspase-8 and -9 expression in intestine, liver and kidney, which were markedly reduced by preconditioning with 2 mg/kg montelukast. Preconditioning with 2 g/kg montelukast significantly attenuated hepatic tissue injury and kidney damage, and decreased plasma interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels in plasma after intestinal IRI. In conclusion, preconditioning with montelukast could attenuate intestinal IRI and the subsequent systemic inflammatory response in rats.

A new parameterization of spectral and broadband ocean surface albedo.

A simple yet accurate parameterization of spectral and broadband ocean surface albedo has been developed. To facilitate the parameterization and its applications, the albedo is parameterized for the direct and diffuse incident radiation separately, and then each of them is further divided into two components: the contributions from surface and water, respectively. The four albedo components are independent of each other, hence, altering one will not affect the others. Such a designed parameterization scheme is flexible for any future update. Users can simply replace any of the adopted empirical formulations (e.g., the relationship between foam reflectance and wind speed) as desired without a need to change the parameterization scheme. The parameterization is validated by in situ measurements and can be easily implemented into a climate or radiative transfer model.

Analytical solution of radiative transfer in the coupled atmosphere-ocean system with a rough surface.

Using the computationally efficient discrete-ordinate method, we present an analytical solution for radiative transfer in the coupled atmosphere-ocean system with a rough air-water interface. The theoretical formulations of the radiative transfer equation and solution are described. The effects of surface roughness on the radiation field in the atmosphere and ocean are studied and compared with satellite and surface measurements. The results show that ocean surface roughness has significant effects on the upwelling radiation in the atmosphere and the downwelling radiation in the ocean. As wind speed increases, the angular domain of sunglint broadens, the surface albedo decreases, and the transmission to the ocean increases. The downward radiance field in the upper ocean is highly anisotropic, but this anisotropy decreases rapidly as surface wind increases and as ocean depth increases. The effects of surface roughness on radiation also depend greatly on both wavelength and angle of incidence (i.e., solar elevation); these effects are significantly smaller throughout the spectrum at high Sun. The model-observation discrepancies may indicate that the Cox-Munk surface roughness model is not sufficient for high wind conditions.