Wintertime grassland dynamics may influence belowground biomass under climate change: a model analysis

Rising temperatures and changes in snow cover, as can be expected under a warmer global climate, may have large impacts on mountain grassland productivity limited by cold and long winters. Here, we combined two existing models, the multi-layer atmosphere-SOiL-VEGetation model (SOLVEG) and the BASic GRAssland model (BASGRA), which accounts for snow, freeze–thaw events, grass growth, and soil carbon balance. The model was applied to simulate the responses of managed grasslands to anomalously warm winter conditions. The grass growth module considered key ecological processes under a cold environment, such as leaf formation, elongation and death, tillering, carbon allocation, and cold acclimation, in terms of photosynthetic activity. Input parameters were derived for two pre-Alpine grassland sites in Germany, for which the model was run using 3 years of data that included a winter with an exceptionally small amount of snow. The model reproduced the temporal variability of observed daily mean heat fluxes, soil temperatures, and snow depth throughout the study period. High physiological activity levels during the extremely warm winter led to a simulated CO2 uptake of 100 gC m−2, which was mainly allocated into the belowground biomass and only to a minor extent used for additional plant growth during early spring. If these temporary dynamics are representative of long-term changes, this process, which is so far largely unaccounted for in scenario analysis using global terrestrial biosphere models, may lead to carbon accumulation in the soil and/or carbon loss from the soil as a response to global warming

Biliary reconstruction with right hepatic lobectomy due to delayed management of laparoscopic bile duct injuries: a case report.

We report a case requiring biliary reconstruction with right hepatic lobectomy due to biliary strictures caused by continuous cholangitis after laparoscopic bile duct injury. The patient, a 55-year-old woman, underwent laparoscopic cholecystectomy for cholelithiasis at another hospital. Although a bile leakage from the intraabdominal drain was observed several days after the operation, the patient was not given adequate treatment to stop the leakage. Two months after the initial laparoscopic cholecystectomy, she was referred to our hospital. Endoscopic retrograde cholangiopancreatography (ERCP) showed complete obstruction of the common hepatic duct, which was caused by clipping during laparoscopic cholecystectomy. Cholangiography from percutaneous transhepatic biliary drainage (PTBD) catheters revealed that sections of the secondary branches of the right intrahepatic bile duct had become constricted due to persistent cholangitis. Fortunately, the left hepatic duct was judged to be normal by imaging. Therefore, we elected to perform a right hepatic lobectomy and left hepaticojejunostomy, because we felt that performing a hepaticojejunostomy without hepatic resection would put the patient at risk of continuing to suffer from cholangitis. The patient was discharged on the 55 th postoperative day, and, 5 years after reconstructive surgery, is healthy and has remained free from biliary strictures in the remnant liver. Appropriate decision-making is essential in the treatment of biliary injury after laparoscopic cholecystectomy. Surgeons should not hesitate to perform biliary reconstruction with hepatic resection to reduce the risk of cholangitis or biliary strictures of the remnant liver. More importantly, preoperative clear imaging of the biliary tree and suitable management of any biliary injury which might occur are necessary to avoid having to perform reconstructive surgery.</p

Biomarkers Predictive of Distant Disease-free Survival Derived from Diffusion-weighted Imaging of Breast Cancer

Purpose: To investigate whether intravoxel incoherent motion (IVIM) and/or non-Gaussian diffusion parameters are associated with distant disease-free survival (DDFS) in patients with invasive breast cancer. Methods: From May 2013 to March 2015, 101 patients (mean age 60.0, range 28-88) with invasive breast cancer were evaluated prospectively. IVIM parameters (flowing blood volume fraction [ɪᴠɪᴍ] and pseudodiffusion coefficient [D*]) and non-Gaussian diffusion parameters (theoretical apparent diffusion coefficient [ADC] at a b value of 0 s/mm² [ADC₀] and kurtosis [K]) were estimated using a diffusion-weighted imaging series of 16 b values up to 2500 s/mm². Shifted ADC values (sADC₂₀₀-₁₅₀₀) and standard ADC values (ADC₀-₈₀₀) were also calculated. The Kaplan-Meier method was used to generate survival analyses for DDFS, which were compared using the log-rank test. Univariable Cox proportional hazards models were used to assess any associations between each parameter and distant metastasis-free survival. Results: The median observation period was 80 months (range, 35-92 months). Among the 101 patients, 12 (11.9%) developed distant metastasis, with a median time to metastasis of 79 months (range, 10-92 months). Kaplan-Meier analysis showed that DDFS was significantly shorter in patients with K > 0.98 than in those with K ≤ 0.98 ( = 0.04). Cox regression analysis showed a marginal statistical association between K and distant metastasis-free survival ( = 0.05). Conclusion: Non-Gaussian diffusion may be associated with prognosis in invasive breast cancer. A higher K may be a marker to help identify patients at an elevated risk of distant metastasis, which could guide subsequent treatment

Effects of adenoviral-mediated hepatocyte growth factor on liver regeneration after massive hepatectomy in rats

Resection is the only curative treatment for liver metastasis of colorectal cancers. Despite the supreme regenerative potential of the liver, major hepatectomy sometimes leads to liver failure, and the limitation of resectable liver volumes makes advanced tumors inoperable. This study was attempted to promote liver regeneration using hepatocyte growth factor (HGF) gene transfection by venous-administered adenovirus and to improve the survival of rats after massive hepatectomy. The adenovirus that encodes HGF was administered to rats before 85%-hepatectomy. The administration of HGF gene improved the survival of rats after massive hepatectomy, while the administration of control adenovirus deteriorated their survival. Gene transfection of HGF showed up-regulation of serum HGF, stimulation of hepatocellular proliferation and rapid liver regeneration. Moreover, HGF administration reduced apoptosis of hepatocytes. The administration of HGF gene prevented liver dysfunction after major hepatectomy and may be a new assist for surgery.</p

Probing the Long Gamma-Ray Burst Progenitor by Lyman-alpha Emission of Host Galaxies

Long gamma-ray bursts (GRBs) have been suggested to occur preferentially in low metallicity environment. We discuss the possibility and theoretical aspects of using Lyman alpha emission properties of long GRB host galaxies as a metallicity indicator of high redshift GRB environments, where direct metallicity measurements are not easy. We propose to use the fraction of Ly-alpha emitters (LAEs) in long GRB host galaxies as a function of UV luminosity, which can be compared with star-formation-rate weighted LAE fraction of Lyman-break galaxies as the standard in the case of no metallicity dependence. There are two important effects of metallicity dependence of long GRB rate to change the LAE fraction of host galaxies. One is the enhancement of intrinsic Ly-alpha equivalent width (EW) by stronger ionizing UV luminosity of low metallicity stellar population, and the other is extinction by interstellar dust to change the observable EW. Based on a latest theoretical model of LAEs that reproduce observations, we argue that the latter is likely to work in the opposite direction to the former, i.e., to decrease LAE fraction if GRBs preferentially occur in low-metallicity environments, because of the clumpy inter-stellar medium effect. The high LAE fraction of GRB host galaxies indicated by observations is quantitatively be explained by the LAE model if GRBs occur when Z < 0.1Z_sun, although this result is still indicative because of the limited statistics and theoretical uncertainties. This result demonstrates that the LAE statistics of GRB hosts may give us useful information in the future.Comment: 10 pages, 6 figures, accepted to ApJ, minor change