Tropospheric methanol observations from space: retrieval evaluation and constraints on the seasonality of biogenic emissions

Methanol retrievals from nadir-viewing space-based sensors offer powerful new information for quantifying methanol emissions on a global scale. Here we apply an ensemble of aircraft observations over North America to evaluate new methanol measurements from the Tropospheric Emission Spectrometer (TES) on the Aura satellite, and combine the TES data with observations from the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp-A satellite to investigate the seasonality of methanol emissions from northern midlatitude ecosystems. Using the GEOS-Chem chemical transport model as an intercomparison platform, we find that the TES retrieval performs well when the degrees of freedom for signal (DOFS) are above 0.5, in which case the model:TES regressions are generally consistent with the model:aircraft comparisons. Including retrievals with DOFS below 0.5 degrades the comparisons, as these are excessively influenced by the a priori. The comparisons suggest DOFS >0.5 as a minimum threshold for interpreting retrievals of trace gases with a weak tropospheric signal. We analyze one full year of satellite observations and find that GEOS-Chem, driven with MEGANv2.1 biogenic emissions, underestimates observed methanol concentrations throughout the midlatitudes in springtime, with the timing of the seasonal peak in model emissions 1-2 months too late. We attribute this discrepancy to an underestimate of emissions from new leaves in MEGAN, and apply the satellite data to better quantify the seasonal change in methanol emissions for midlatitude ecosystems. The derived parameters (relative emission factors of 11.0, 0.26, 0.12 and 3.0 for new, growing, mature, and old leaves, respectively, plus a leaf area index activity factor of 0.5 for expanding canopies with leaf area index <1.2) provide a more realistic simulation of seasonal methanol concentrations in midlatitudes on the basis of both the IASI and TES measurements.

The application of a violence risk assessment tool among Chinese psychiatric service users: a preliminary study

The Violence Risk Screening-10 (V-RISK-10) is one of the few instruments available for evaluating violence risk among general psychiatric service users. This naturalistic prospective study involved 376 inpatients in a general psychiatric hospital in Beijing and intended to determine whether this brief instrument could be applied to a sample of Chinese consumers and whether its predictive properties could be retained. Risk assessment at admission was compared to the record of aggression and violence during the first month of hospitalization. During the research period, 108 of the 376 consumers caused 265 incidences of aggression. Receiver operating characteristics for the V-RISK-10 Chinese version yielded an area under the curve of 0.63. Its sensitivity/specificity was 0.80/0.38 and the corresponding positive/negative predictive value was 0.34/0.82. Intraclass correlation coefficient for the whole instrument was 0.89. Compared to the results of the original V-RISK-10, its predictive accuracy was lower. However, with some modification, the V-RISK-10 still shows promise as an instrument for use in daily practice in Chinese clinical settings.

A time-varying source connectivity approach to reveal human somatosensory information processing

Exploration of neural sources and their effective connectivity based on transient changes in electrophysiological activities to external stimuli is important for understanding brain mechanisms of sensory information processing. However, such cortical mechanisms have not yet been well characterized in electrophysiological studies since (1) it is difficult to estimate the stimulus-activated neural sources and their activities and (2) it is difficult to identify transient effective connectivity between neural sources in the order of milliseconds. To address these issues, we developed a time-varying source connectivity approach to effectively capture fast-changing information flows between neural sources from high-density Electroencephalography (EEG) recordings. This time-varying source connectivity approach was applied to somatosensory evoked potentials (SEPs), which were elicited by electrical stimulation of right hand and recorded using 64 channels from 16 subjects, to reveal human somatosensory information processing. First, SEP sources and their activities were estimated, both at single-subject and group level, using equivalent current dipolar source modeling. Then, the functional integration among SEP sources was explored using a Kalman smoother based time-varying effective connectivity inference method. The results showed that SEPs were mainly generated from the contralateral primary somatosensory cortex (SI), bilateral secondary somatosensory cortex (SII), and cingulate cortex (CC). Importantly, we observed a serial processing of somatosensory information in human somatosensory cortices (from SI to SII) at earlier latencies (<150 ms) and a reciprocal processing between SII and CC at later latencies (>200 ms).

Dynamic characteristics of multisensory facilitation and inhibition

Multimodal integration, which mainly refers to multisensory facilitation and multisensory inhibition, is the process of merging multisensory information in the human brain. However, the neural mechanisms underlying the dynamic characteristics of multimodal integration are not fully understood. The objective of this study is to investigate the basic mechanisms of multimodal integration by assessing the intermodal influences of vision, audition, and somatosensory sensations (the influence of multisensory background events to the target event). We used a timed target detection task, and measured both behavioral and electroencephalographic responses to visual target events (green solid circle), auditory target events (2 kHz pure tone) and somatosensory target events (1.5 ± 0.1 mA square wave pulse) from 20 normal participants. There were significant differences in both behavior performance and ERP components when comparing the unimodal target stimuli with multimodal (bimodal and trimodal) target stimuli for all target groups. Significant correlation among reaction time and P3 latency was observed across all target conditions. The perceptual processing of auditory target events (A) was inhibited by the background events, while the perceptual processing of somatosensory target events (S) was facilitated by the background events. In contrast, the perceptual processing of visual target events (V) remained impervious to multisensory background events.

First Report of a Leaf Spot on Conyza sumatrensis Caused by Phoma macrostoma in China

Conyza sumatrensis (Asteraceae), an annual or biennial plant, is native to North and South America. It is an invasive, noxious weed that is widespread in southern and southeastern China. It invades farm land and causes great losses to dry land crops, including wheat, corn, and beans. It also reduces biological diversity by crowding out native plants in the infested areas (3,4). During a search for fungal pathogens that could serve as potential biological control agents of C. sumatrensis, a leaf spot disease was observed in 2010 in Chongqing, China. An isolate (SMBC22) of a highly virulent fungus was obtained from diseased leaves. Pathogenicity tests were performed by placing 6-mm-diameter mycelial disks of 7-day-old potato dextrose agar (PDA) cultures of SMBC22 on leaves of 15 healthy greenhouse-grown plants of C. sumatrensis; the same number of control plants was treated with sterile PDA disks. Treated plants were covered with plastic bags for 24 h and maintained in a growth chamber with daily average temperatures of 24 to 26°C, continuous light (3,100 lux), and high relative humidity (>90%). Lesions similar to those observed in the field were first obvious on the SMBC22-inoculated leaves 3 days after inoculation. Symptoms became severe 7 to 9 days after inoculation. Control plants remained healthy. The fungus was reisolated from inoculated and diseased leaves and it was morphologically the same as SMBC22. The pathogenicity test was conducted three times. A survey of 10 southern and southeastern Chinese provinces revealed that the disease was widespread and it attacked leaves and stems of seedlings and mature plants of C. sumatrensis. Lesions on leaves were initially small, circular, and water soaked. The typical lesion was ovoid or fusiform, dark brown, and surrounded by a yellow halo. The spots coalesced to form large lesions and plants were often completely blighted. Fungal colonies of SMBC22 on PDA plates were initially white and turned dark gray. Colonies were circular with smooth edges with obvious rings of pycnidia on the surface. Aerial hyphae were short and dense. Pycnidia, black and immersed or semi-immersed in the medium, were visible after 12 days of incubation. Pycnidia were 72 to 140 μm in diameter. Conidia were produced in the pycnidia and were hyaline, unicellular, ellipsoidal, and 4.4 to 6.1 × 1.6 to 2.2 μm. To confirm identification of the fungus, genomic DNA was extracted from mycelia of a 7-day-old culture on PDA at 25°C (2). The internal transcribed spacer (ITS) gene of rDNA was amplified using primers ITS4/ITS5. The gene sequence was 524 bp long and registered in NCBI GenBank (No. HQ645974). BLAST analysis showed that the current sequence had 99% homology to an isolate of Phoma macrostoma (DQ 404792) from Cirsium arvense (Canada thistle) in Canada and reported to cause chlorotic symptoms on that host plant (1). To our knowledge, this is the first report of P. macrostoma causing disease on C. sumatrensis in China. P. macrostoma, thought of as a biocontrol agent of broadleaf weeds in Canada, has been patented in the United States. The current isolate of P. macrostoma is considered as a potential biocontrol agent of C. sumatrensis. References: (1) P. R. Graupner et al. J. Nat. Prod. 66:1558, 2004. (2) S. Takamatsu et al. Mycoscience 42:135, 2001. (3) W. Z. Tan et al. Page 177 in: Manual of Emergency Control Technology Invasive Pests in China. G. L. Zhang, ed. Science Press, Beijing, 2010. (4) C. Wang et al. J. Wuhan Bot. Res. 28:90, 2010.

Clinical efficacy of chemotherapy combined with verapamil in metastatic colorectal patients

In order to determine the clinical efficacy and adverse reactions of chemotherapy and verapamil infusion through a target artery to treat colorectal cancer patients with metastasis after failure with previous conventional treatments. Patients with metastatic colon cancer (n = 36) received an infusion of verapamil, interleukin-2, oxaliplatin (or hydroxy camptothecin or irinotecan hydrochloride), fluorouracil and calcium folinate through target artery using the Seldinger puncture technique. From the second day of infusion, the patients were treated with fluorouracil and calcium folinate via systematic intravenous injection for 2-3 days. Efficacy was evaluated after at least two treatment courses. The objective response including complete or partial response was 58.3% in the 36 patients; clinical benefit rate, evaluated by Karnofsky Performance Status score was 91.7%; by weight was 83.3%; by the amount of painkiller consumed was 80.6%. No patient experienced side effects associated with heart function. Post-treatment, the P-R period, Q-T period, QRS, and heart rate were not significantly different than before treatment. Liver function was significantly improved. Side effects of chemotherapy were minor in comparison to those observed with intravenous chemotherapy. Infusion of verapamil and chemotherapy directly into pelvic tumor tissue can increase treatment efficacy and has been shown to be a relatively safe technique.

Tranilast prevents the progression of chronic cyclosporine nephrotoxicity through regulation of transforming growth factor β/Smad pathways

PURPOSE

Our aim was to investigate the role of tranilast in transforming growth factor (TGF) β/Smad pathways using a rat model of chronic cyclosporine (CsA) nephrotoxicity.

METHODS

Thirty Sprague-Dawley (SD) rats were equally randomized in to 5 groups for gavage treatments daily for 4 weeks: normal control (N), olive oil; CsA (25 mg/kg), (M) CsA plus low-dose tranilast group (T1; CsA 25 mg/kg and tranilast 100 mg/kg); CsA plus medium-dose tranilast group (T2; CsA 25 mg/kg and tranilast 200 mg/kg); and CsA plus high-dose tranilast group (T4; CsA 25 mg/kg and tranilast 400 mg/kg). Kidneys were harvested at the end of the fourth week. TGF-β1 as well as Smad3 and Smad7 were detected by reverse-transcription polymerase chain reaction and immunohistochemistry.

RESULTS

The administration of tranilast decreased the expression of TGF-β1 and Smad3 by CsA-treated rats, whereas it increased both mRNA and protein levels of Smad7. Semiquantitative analysis of mRNA production revealed these treatments to markedly reduce the amount of TGF-β1: T1: 0.8452 ± 0.0825 vs 0.8529 ± 0.0606 (P < .05); T2: 0.8414 ± 0.0696 vs 0.8529 ± 0.0606 (P < .05); T4: 0.8336 ± 0.0592 vs 0.8529 ± 0.0606 (P < .05). For Smad3: T1: 0.8581 ± 0.0328 vs 0.8613 ± 0.0542 (P < .05); T2: 0.8528 ± 0.0599 vs 0.8613 ± 0.0542 (P < .05); T4: 0.8436 ± 0.0185 vs 0.8613 ± 0.0542 (P < .05). The significantly elevated dose-dependent amounts of Smad7 were: T1: 0.9026 ± 0.0522 vs 0.8678 ± 0.0246, (P < .05); T2: 0.9087 ± 0.0506 vs 0.8678 ± 0.0246 (P < .05); T4: 0.9151 ± 0.0793 vs 0.8678 ± 0.0246 (P < .05).

CONCLUSION

Regulation of TGF-β/Smad pathways is one of the mechanisims by which tranilast mitigates the progression of chronic CsA nephrotoxicity in rats.

Genetic variations and heterosexual HIV-1 infection: analysis of clustered genes encoding CC-motif chemokine ligands

Several CC-motif chemokine ligands (CCLs) can block HIV-1-binding sites on CC-motif chemokine receptor 5 (CCR5) and inhibit viral entry. We studied single-nucleotide polymorphisms (SNPs) in genes encoding three CCR5 ligands (CCL3 (MIP-1a), CCL4 (MIP-1b)and CCL5 (RANTES)) along with an adjacent gene encoding a CCR2ligand (CCL2 (MCP-1)) to identify candidate markers for HIV-1 infection and pathogenesis. Analyses of 567 HIV-1 serodiscordant Zambian couples revealed that rs5029410C (in CCL3 intron 2) was associated with lower viral load (VL) in seroconverters, adjusted for gender and age (regression β=-0.57 log(10), P=4x10(-6)). Inaddition, rs34171309A in CCL3 exon 3 was associated with increased risk of HIV-1 acquisition in exposed seronegatives(hazard ratio=1.52, P=0.006 when adjusted for VL of the initially seropositive partner and genital ulcer/inflammation). SNPrs34171309 encodes a conservative Glu-to-Asp substitution. Fiven eighboring SNPs in tight linkage disequilibrium with rs34171309all showed similar associations with HIV-1 acquisition. How these multiple CCL3 SNPs may alter the occurrence or course of HIV-1 infection remains to be determined [corrected].

Taking into account latency, amplitude, and morphology: improved estimation of single-trial ERPs by wavelet filtering and multiple linear regression

Across-trial averaging is a widely used approach to enhance the signal-to-noise ratio (SNR) of event-related potentials (ERPs). However, across-trial variability of ERP latency and amplitude may contain physiologically relevant information that is lost by across-trial averaging. Hence, we aimed to develop a novel method that uses 1) wavelet filtering (WF) to enhance the SNR of ERPs and 2) a multiple linear regression with a dispersion term (MLR(d)) that takes into account shape distortions to estimate the single-trial latency and amplitude of ERP peaks. Using simulated ERP data sets containing different levels of noise, we provide evidence that, compared with other approaches, the proposed WF+MLR(d) method yields the most accurate estimate of single-trial ERP features. When applied to a real laser-evoked potential data set, the WF+MLR(d) approach provides reliable estimation of single-trial latency, amplitude, and morphology of ERPs and thereby allows performing meaningful correlations at single-trial level. We obtained three main findings. First, WF significantly enhances the SNR of single-trial ERPs. Second, MLR(d) effectively captures and measures the variability in the morphology of single-trial ERPs, thus providing an accurate and unbiased estimate of their peak latency and amplitude. Third, intensity of pain perception significantly correlates with the single-trial estimates of N2 and P2 amplitude. These results indicate that WF+MLR(d) can be used to explore the dynamics between different ERP features, behavioral variables, and other neuroimaging measures of brain activity, thus providing new insights into the functional significance of the different brain processes underlying the brain responses to sensory stimuli.

The primary somatosensory cortex largely contributes to the early part of the cortical response elicited by nociceptive stimuli

Research on the cortical sources of nociceptive laser-evoked brain potentials (LEPs) began almost two decades ago (Tarkka and Treede, 1993). Whereas there is a large consensus on the sources of the late part of the LEP waveform (N2 and P2 waves), the relative contribution of the primary somatosensory cortex (S1) to the early part of the LEP waveform (N1 wave) is still debated. To address this issue we recorded LEPs elicited by the stimulation of four limbs in a large population (n=35). Early LEP generators were estimated both at single-subject and group level, using three different approaches: distributed source analysis, dipolar source modeling, and probabilistic independent component analysis (ICA). We show that the scalp distribution of the earliest LEP response to hand stimulation was maximal over the central-parietal electrodes contralateral to the stimulated side, while that of the earliest LEP response to foot stimulation was maximal over the central-parietal midline electrodes. Crucially, all three approaches indicated hand and foot S1 areas as generators of the earliest LEP response. Altogether, these findings indicate that the earliest part of the scalp response elicited by a selective nociceptive stimulus is largely explained by activity in the contralateral S1, with negligible contribution from the secondary somatosensory cortex (S2).

Isotropic non-ideal cloaks providing improved invisibility by adaptive segmentation and optimal refractive index profile from ordering isotropic materials

Mimicking the ideal cloak, which is anisotropic and inhomogeneous, can be achieved by alternating homogeneous isotropic materials, whose permittivity and permeability of each isotropic coating can be determined from effective medium theory. An improved two-fold method is proposed by optimally discretizing the cloak and re-ordering the combination of the effective parameters of each layer to form a smooth step-index profile. The roles of impedance matching and index matching are investigated for cloaking effects. Smoothing the index profile leads to better invisibility than that obtained by smoothing the impedance profile, since the forward scattering can be further diminished. Nonlinear-transformationbased spherical ideal cloaks are studied, and improved design method is explored together with different segmentation schemes. Significant improvement in invisibility is always observed for the optimal segmentation in virtual space with the proposed two-fold design method no matter how nonlinear the coordinate transformation is.