Emission from field burning of crop residue, a common practice in many parts of the world today, has potential effects on air quality, atmosphere and climate. This study provides a comprehensive size ...and compositional characterization of particulate matter (PM) emission from rice straw (RS) burning using both
in situ experiments (11 spread field burning) and laboratory hood experiments (3 pile and 6 spread burning) that were conducted during 2003-2006 in Thailand. The carbon balance and emission ratio method was used to determine PM emission factors (EF) in the field experiments. The obtained EF varied from field to hood experiments reflecting multiple factors affecting combustion and emission. In the hood experiments, EF were found to be depending on the burning types (spread or pile), moisture content and the combustion efficiency. In addition, in the field experiments, burning rate and EF were also influenced by weather conditions, i.e. wind. Hood pile burning produced significantly higher EF (20
±
8
g
kg
−1 RS) than hood spread burning (4.7
±
2.2
g
kg
−1 RS). The majority of PM emitted from the field burning was PM
2.5 with EF of 5.1
±
0.7
g
m
−2 or 8.3
±
2.7
g
kg
−1 RS burned. The coarse PM fraction (PM
10–2.5) was mainly generated by fire attention activities and was relatively small, hence the resulting EF of PM
10 (9.4
±
3.5
g
kg
−1 RS) was not significantly higher than PM
2.5. PM size distribution was measured across 8 size ranges (from <0.4
μm to >9.0
μm). The largest fractions of PM, EC and OC were associated with PM
1.1. The most significant components in PM
2.5 and PM
10 include OC, water soluble ions and levoglucosan. Relative abundance of some methoxyphenols (e.g., acetylsyringone), PAHs (e.g., fluoranthene and pyrene), organochlorine pesticides and PCBs may also serve as additional signatures for the PM emission. Presence of these toxic compounds in PM of burning smoke increases the potential toxic effects of the emission. For illustration, an estimation of the annual RS field burning in Thailand was made using the obtained
in situ field burning EF and preliminary burning activity data.
Background
While the majority of studies report that a raised serum α‐fetoprotein (AFP) level before operation is associated with a high risk of recurrence and death in patients who undergo ...hepatectomy for hepatocellular carcinoma (HCC), results are conflicting. The aim of this study was to assess the prognostic value of AFP.
Methods
Serum AFP levels were measured in patients with hepatitis‐associated HCC who underwent hepatectomy between 1995 and 2012. Kaplan–Meier and multivariable analyses were performed to identify risk factors for overall and disease‐free survival. Univariable and multivariable Cox proportional hazards regression was used to evaluate the predictive value of AFP. Receiver operating characteristic (ROC) curves were generated to identify the AFP level that had the highest accuracy in discriminating between survivors and non‐survivors.
Results
Some 376 patients with hepatitis B virus (HBV)‐associated HCC were included in the study. The overall survival rate was 58·8 per cent in patients with an AFP level of 400 ng/ml or less compared with 40·4 per cent for those with a level exceeding 400 ng/ml (P = 0·001). AFP concentration above 400 ng/ml was an independent risk factor for shorter disease‐free and overall survival after surgery. ROC analysis indicated that the optimal cut‐off values for AFP varied for different subtypes of HCC. The sensitivity and specificity were lower with areas under the ROC curve of less than 0·600. An AFP level greater than 400 ng/ml was not sensitive enough to predict the prognosis in patients with an HCC diameter smaller than 3 cm.
Conclusion
A serum AFP level above 400 ng/ml predicts poor overall and recurrence‐free survival after hepatectomy in patients with HBV‐associated HCC. AFP is not a strong prognostic marker given its poor discriminatory power, with low sensitivity and specificity.
Not useful
The coupling of the ionosphere to processes from below remains an elusive and difficult problem, as rapidly changing external drivers from above mask variations related to lower atmospheric sources. ...Here we use superposition of unique circumstances, current deep solar minimum and a record‐breaking stratospheric warming event, to gain new insights into causes of ionospheric perturbations. We show large (50–150%) persistent variations in the low‐latitude ionosphere (200–1000 km) that occur several days after a sudden warming event in the high‐latitude winter stratosphere (∼30 km). We rule out solar irradiance and geomagnetic activity as explanations of the observed variation. Using a general circulation model, we interpret these observations in terms of large changes in atmospheric tides from their nonlinear interaction with planetary waves that are strengthened during sudden warmings. We anticipate that further understanding of the coupling processes with planetary waves, accentuated during the stratospheric sudden warming events, has the potential of enabling the forecast of low‐latitude ionospheric weather up to several days in advance.
Anthracnose caused by Colletotrichum species is a serious disease of more than 30 plant genera. Several Colletotrichum species have been reported to infect chili in different countries. Although ...China is the largest chiliproducing country, little is known about the species
that have been infecting chili locally. Therefore, we collected samples of diseased chili from 29 provinces of China, from which 1285 strains were isolated. The morphological characters of all strains were observed and compared, and multi-locus phylogenetic analyses (ITS, ACT, CAL, CHS-1,
GAPDH, TUB2, and HIS3) were performed on selected representative strains. Fifteen Colletotrichum species were identified, with C. fioriniae, C. fructicola, C. gloeosporioides, C. scovillei, and C. truncatum being prevalent. Three new species, C. conoides, C. grossum,
and C. liaoningense, were recognised and described in this paper. Colletotrichum aenigma, C. cliviae, C. endophytica, C. hymenocallidis, C. incanum, C. karstii, and C. viniferum were reported for the first time from chili. Pathogenicity of all species isolated from chili
was confirmed, except for C. endophytica. The current study improves the understanding of species causing anthracnose on chili and provides useful information for the effective control of the disease in China.
The Earth's thermosphere and ionosphere (TI) are characterized by perpetual variability as integral parts of the atmosphere system, with intermittent disturbances from solar and geomagnetic forcing. ...This review examines how the TI variability is affected by processes originating from the lower atmosphere and implications for quantifying and forecasting the TI. This aspect of the TI variability has been increasingly appreciated in recent years from both observational and numerical studies, especially during the last extended solar minimum. This review focuses on the role of atmospheric waves, including tides, planetary waves, gravity waves, and acoustic waves, which become increasingly significant as they propagate from their source region to the upper atmosphere. Recent studies have led to better understanding of how these waves directly or indirectly affect TI wind, temperature, and compositional structures; the circulation pattern; neutral and ion species transport; and ionospheric wind dynamo. The variability of these waves on daily to interannual scales has been found to significantly impact the TI variability. Several outstanding questions and challenges have been highlighted: (i) large, seemingly stochastic, day‐to‐day variability of tides in the TI; (ii) control of model error in the TI region by the lower atmosphere; and (iii) the increasing importance of processes with shorter spatial and temporal scales at higher altitudes. Addressing these challenges requires model capabilities to assimilate observations of both lower and upper atmosphere and higher model resolution to capture complex interactions among processes over a broad range of scales and extended altitudes.
Key Points
Review the role of waves from lower atmosphere in thermosphere/ionosphere (TI) variability
Elucidate how predictability of the TI is affected by the lower atmosphere
Highlight outstanding questions in studying lower/upper atmosphere coupling
AIMS: The influence of bacterial species/strains in agitated culture was investigated on the morphology and structure characteristics of bacterial cellulose. METHODS AND RESULTS: Komagataeibacter ...nataicola Y19 and Gluconacetobacter entanii ACCC10215 were inoculated in Hestrin–Schramm (HS) medium and subjected to agitated cultivation. Different kinds of BCs were obtained including flocky asterisk‐like BC by G. entanii ACCC10215 and solid sphere‐like BC by K. nataicola Y19. The SEM results showed that the asterisk‐like BC had larger pores than the solid sphere‐like BC. The FT‐IR and X‐ray diffraction results showed the asterisk‐like BC had lower crystallinity (81·43%), higher cellulose Iα mass fraction (79·74%) and smaller crystallite size. CONCLUSIONS: The different species/strains can influence the morphology and structure characteristics of BC in agitated culture. SIGNIFICANCE AND IMPACT OF THE STUDY: We examined the influence of different species/strains on the morphology, macro‐ and microstructure of BCs produced in agitated culture for the first time, which suggest that different BCs with potential applications could be obtained by choosing different species or strains and fermentation method.
BACKGROUND: Although metabolic syndrome (MetS) has been reported to be associated with cognitive decline and dementia, little was known about late-life MetS and cognitive decline among older old ...population. The main purpose of this study was to evaluate the role of MetS and cognitive decline among men aged 75 and over in Taiwan. METHODS: This is a prospective cohort study which recruited men aged 75 years and older with intact cognitive function living in the Banciao Veterans Home, a retirement community for veterans in northern Taiwan. All participants received complete history taking, physical examinations, global cognitive tests and laboratory tests. Cognitive status was re-evaluated one year after enrollment to evaluate the role of MetS to cognitive decline in this study population. RESULTS: Overall, 338 people participated in the study and 62 of them were excluded due to low baseline MMSE score, and the remaining 276 people (mean age: 82.4±4.2 years) were enrolled for study. The prevalence of MetS and annual cognitive decline were 22.5% and 15.6%, respectively. During the follow-up period, 9 (3.3%) participants died, 229(83.0%) complete the study. Subjects with cognitive decline were older and had lower serum levels of serum total cholesterol. Multivariate logistic regression showed that older age (OR:1.13, 95% C.I.: 1.01–1.25, P=0.026) and central obesity (OR: 4.19, 95% CI: 1.26–13.91, P=0.019) were independent risk factors for cognitive decline; and MetS defined by Adult Treatment Panel III was a protective factor (OR: 0.20, 95% CI: 0.04–0.94, P=0.041). The protective effect of MetS remained the same when MetS was defined by the criteria of International Diabetes Federation. CONCLUSIONS: Age and central obesity were significant risk factors of cognitive decline, but late-life MetS, however defined, had protective effect on cognitive function. Further investigation is needed to clarify the possible mechanism of MetS and cognitive function in older adults.
Background & Aims Subtle inter-patient genetic variation and environmental factors combine to determine disease progression in non-alcoholic fatty liver disease (NAFLD). Carriage of the PNPLA3 ...rs738409 c.444C >G minor allele (encoding the I148M variant) has been robustly associated with advanced NAFLD. Although most hepatocellular carcinoma (HCC) is related to chronic viral hepatitis or alcoholic liver disease, the incidence of NAFLD-related HCC is increasing. We examined whether rs738409 C >G was associated with HCC-risk in patients with NAFLD. Methods PNPLA3 rs738409 genotype was determined by allelic discrimination in 100 European Caucasians with NAFLD-related HCC and 275 controls with histologically characterised NAFLD. Results Genotype frequencies were significantly different between NAFLD-HCC cases (CC = 28, CG = 43, GG = 29) and NAFLD-controls (CC = 125, CG = 117, GG = 33) ( p = 0.0001). In multivariate analysis adjusted for age, gender, diabetes, BMI, and presence of cirrhosis, carriage of each copy of the rs738409 minor (G) allele conferred an additive risk for HCC (adjusted OR 2.26 95% CI 1.23–4.14, p = 0.0082), with GG homozygotes exhibiting a 5-fold 1.47–17.29, p = 0.01 increased risk over CC. When compared to the UK general population (1958 British Birth Cohort, n = 1476), the risk-effect was more pronounced (GC vs. CC: unadjusted OR 2.52 1.55–4.10, p = 0.0002; GG vs. CC: OR 12.19 6.89–21.58, p <0.0001). Conclusions Carriage of the PNPLA3 rs738409 C >G polymorphism is not only associated with greater risk of progressive steatohepatitis and fibrosis but also of HCC. If validated, these findings suggest that PNPLA3 genotyping has the potential to contribute to multi-factorial patient-risk stratification, identifying those to whom HCC surveillance may be targeted.
Numerical simulations are performed for a sudden stratosphere warming (SSW) under different atmospheric tide and planetary wave forcing conditions to investigate the tidal variability in the ...mesosphere and lower thermosphere (MLT). The influence of variability of different tides in the MLT on generating perturbations to the low latitude ionosphere is also investigated. Significant changes are found to occur in the migrating semidiurnal solar (SW2) and lunar (M2) tides as well as in the westward propagating nonmigrating semidiurnal tide with zonal wave number 1 (SW1). The changes in the zonal mean atmosphere that occur during SSWs lead to an enhancement in the SW2 and M2 tides. The vertical wavelength of the SW2 is also changed, resulting in phase variability in the SW2 at a constant altitude. Significant enhancements in the SW1 are found to occur only in the presence of additional planetary wave forcing, and this demonstrates that nonlinear planetary wave‒tide interactions lead to the enhanced SW1 during SSWs. The amplitude and phase variability of the SW2 is found to be capable of producing temporal variability in the vertical plasma drift velocity that is similar to the observed variability. Changes in the M2 during SSWs can contribute up to an additional ∼30% of the total ionosphere variability; however, the overall influence of the lunar tide is found to be dependent upon the phase of the moon relative to the timing of the SSW. Although the influence is relatively minor, the SW1 also contributes to the low latitude ionosphere variability during SSWs. The simulation results for the vertical plasma drift velocity and total electron content (TEC) further illustrate that significant longitude variability occurs in the ionosphere response to SSWs.
Key Points
SW2, SW1, and M2 tides all contribute to ionosphere response to SSWs.
Lunar tide contributes ~30% of ionosphere response to SSWs.
Ionosphere response to SSW exhibits significant longitude dependence.
We report the first results of a global ionosphere/thermosphere simulation study that self‐consistently generates large‐scale equatorial spread F (ESF) plasma bubbles in the postsunset ionosphere. ...The coupled model comprises the ionospheric code SAMI3 and the atmosphere/thermosphere code WACCM‐X. Two cases are modeled for different seasons and geophysical conditions: the March case (low solar activity: F10.7 = 70) and the July case (high solar activity: F10.7 = 170). We find that equatorial plasma bubbles formed and penetrated into the topside F layer for the March case but not the July case. For the March case, a series of bubbles formed in the Atlantic sector with irregularity spacings in the range 400–1,200 km, rose to over 800 km, and persisted until after midnight. These results are consistent with recent GOLD observations. Calculation of the generalized Rayleigh‐Taylor instability (GRTI) growth rate shows that the e‐folding time was shorter for the March case than the July case.
Key Points
The first results from a high‐resolution, global simulation of equatorial spread F using realistic thermospheric conditions
The development of equatorial plasma bubbles is both longitudinally and seasonally dependent
Atmospheric waves play an essential role in “seeding” the generalized Rayleigh‐Taylor instability responsible for the instability
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