A two-fold increase of carbon cycle sensitivity to tropical temperature variations

Earth system models project that the tropical land carbon sink will decrease in size in response to an increase in warming and drought during this century, probably causing a positive climate feedback. But available data are too limited at present to test the predicted changes in the tropical carbon balance in response to climate change. Long-term atmospheric carbon dioxide data provide a global record that integrates the interannual variability of the global carbon balance. Multiple lines of evidence demonstrate that most of this variability originates in the terrestrial biosphere. In particular, the year-to-year variations in the atmospheric carbon dioxide growth rate (CGR) are thought to be the result of fluctuations in the carbon fluxes of tropical land areas. Recently, the response of CGR to tropical climate interannual variability was used to put a constraint on the sensitivity of tropical land carbon to climate change. Here we use the long-term CGR record from Mauna Loa and the South Pole to show that the sensitivity of CGR to tropical temperature interannual variability has increased by a factor of 1.9 ± 0.3 in the past five decades. We find that this sensitivity was greater when tropical land regions experienced drier conditions. This suggests that the sensitivity of CGR to interannual temperature variations is regulated by moisture conditions, even though the direct correlation between CGR and tropical precipitation is weak. We also find that present terrestrial carbon cycle models do not capture the observed enhancement in CGR sensitivity in the past five decades. More realistic model predictions of future carbon cycle and climate feedbacks require a better understanding of the processes driving the response of tropical ecosystems to drought and warming.

A new high-resolution N2O emission inventory for China in 2008

The amount and geographic distribution of N2O emissions over China remain largely uncertain. In this study, county-level and 0.1° × 0.1° gridded anthropogenic N2O emission inventories for China (PKU-N2O) in 2008 are developed based on high-resolution activity data and regional emission factors (EFs) and parameters. These new estimates are compared with previous inventories, and with two sensitivity tests: one that uses high-resolution activity data but the default IPCC methodology (S1) and the other that uses regional EFs and parameters but starts from coarser-resolution activity data. The total N2O emissions are 2150 GgN2O/yr (interquartile range from 1174 to 2787 GgN2O/yr). Agriculture contributes 64% of the total, followed by energy (17%), indirect emissions (12%), wastes (5%), industry (2.8%), and wildfires (0.2%). Our national emission total is 17% greater than that of the EDGAR v4.2 global product sampled over China and is also greater than the GAINS-China, NDRC, and S1 estimates by 10%, 50%, and 17%, respectively. We also found that using uniform EFs and parameters or starting from national/provincial data causes systematic spatial biases compared to PKU-N2O. Spatial analysis shows nonlinear relationships between N2O emission intensities and urbanization. Per-capita and per-GDP N2O emissions increase gradually with an increase in the urban population fraction from 0.3 to 0.9 among 2884 counties, and N2O emission density increases with urban expansion.

Expression pattern of Ngn3 in dairy goat testis and its function in promoting meiosis by upregulating Stra8

OBJECTIVES

Ngn3 is a typical transcription factor and marker of differentiating spermatogonial stem cells (SSCs) in mouse, belonging to the basic helix-loop-helix (bHLH) family. Its gene is specifically expressed in A type spermatogonia in mouse testis, thus plays a critical role in controlling differentiation of SSCs. However, roles of Ngn3 and its protein in dairy goat testis remain unknown.

MATERIALS AND METHODS

Testis development and expression patterns of Ngn3 were analysed by immunofluorescence and quantitative reverse transcription-polymerase chain reaction (QRT-PCR) in the dairy goat. Furthermore, effects of its overexpression on male germline stem cells (mGSCs) were evaluated by QRT-PCR, immunofluorescence, luciferase reporter assay and western blotting.

RESULTS

Revealed that Ngn3 was expressed more highly during puberty and in the adult than in testis of other ages. Overexpression of Ngn3 promoted expression of meiosis-related gene Stra8 and stem-cell differentiation marker CD117, but suppressed expression of Plzf, a classical marker of SSCs. Furthermore, Ngn3 did not promote expression of Stra8 directly as shown in transcription and translation levels detected by luciferase reporter assay and western blotting.

CONCLUSIONS

Taken together, these results suggest that Ngn3 plays an important role in spermatogenesis and that overexpression of Ngn3 can promote meiosis in testis of the dairy goat.

Location and characterization of female germline stem cells (FGSCs) in juvenile porcine ovary

OBJECTIVES

Existence of germline stem cells (GSCs) in juvenile mammalian female ovaries has been drastically debated recently since reports that adult mouse ovaries still have mitotically active germ cells have been proposed. In addition, definitive location of such female germline stem cells (FGSCs) had not been demonstrated.

MATERIALS AND METHODS

We segregated porcine FGSCs mechanically from ovary cortex, and tested our hypotheses by utilizing immunofluorescent staining, qRT-PCR and western blotting.

RESULTS

We attached emphasis to unambiguous location of FGSCs, which settle simultaneously in the theca. Dissected cells from porcine thecal layers maintained similar characteristics to mouse FGSCs and ESCs over 4-months in vitro culture.

CONCLUSION

These results may provide a new resource for the study of oogenesis and therapy for ovarian sterility.

miR-34c works downstream of p53 leading to dairy goat male germline stem-cell (mGSCs) apoptosis

OBJECTIVES

Recent lines of evidence have indicated that miR-34c can play important roles in regulation of the cell cycle, cell senescence and apoptosis of mouse and human tumour cells, spermatogenesis, and male germ-cell apoptosis. However, there is little information on the effects of miR-34c on proliferation and apoptosis of livestock male germ cells. The dairy goat is a convenient domestic species for biological investigation and application. The purpose of this study was to investigate the effects of miR-34c on apoptosis and proliferation of dairy goat male germline stem cells (mGSCs), as well as to determine the relationship between p53 and miR-34c in this species.

MATERIALS AND METHODS

Morphological observation, miRNA in situ hybridisation (ISH), bromodeoxyuridine staining, flow cytometry, quantitative-RT-PCR (Q-RT-PCR) and western blotting were utilized to ascertain apoptosis and proliferation of mGSCs, through transfection of miR-34c mimics (miR-34c), miR-34c inhibitor (anti-miR-34c), miR-34c mimics and inhibitors co-transfected (mixture) compared to control groups.

RESULTS

Results manifested that miR-34c over-expression promoted mGSCs apoptosis and suppressed their proliferation. Simultaneously, a variety of apoptosis-related gene expression was increased while some proliferation-related genes were downregulated. Accordingly, miR-34c promoted apoptosis in mGSCs and reduced their proliferation; moreover, expression of miR-34c was p53-dependent.

CONCLUSIONS

This study is the first to provide a model for study of miRNAs and mechanisms of proliferation and apoptosis in male dairy goat germ cells.

Short communication: heat resistance of Escherichia coli strains in raw milk at different subpasteurization conditions

A commonly applied treatment of raw milk to reduce bacterial loads is the short-time application of heat at subpasteurization levels under continuous flow, generally referred to as thermization, because this method retains some of the beneficial properties of raw milk. In a previous study, Escherichia coli strains exhibiting increased thermotolerance were found, demanding investigations into their ability to survive thermization. Nine E. coli strains, including 4 Shiga toxin-producing E. coli (STEC) strains, were investigated for their reduction during a thermization treatment in raw milk using a pilot-plant pasteurizer to reflect typically applied commercial conditions. Six of the 9 E. coli strains, including the 4 STEC strains, were similarly inactivated at 60, 62.5, and 65°C, whereas increased thermotolerance was observed for 3 E. coli strains. All strains were reduced to <2 log10 at 60 and 62.5°C within 25s. At 65°C, 6 of 9 E. coli strains were reduced by at least 5 log10 after 25s, whereas at 67.5°C, such a reduction was observed for 8 strains. A much higher thermotolerance was found for E. coli strain FAM21805. For some E. coli strains, time-temperature combinations above 65°C were required to obtain a substantial reduction during a thermization treatment.

Experimental demonstration of an OpenFlow based software-defined optical network employing packet, fixed and flexible DWDM grid technologies on an international multi-domain testbed

Software defined networking (SDN) and flexible grid optical transport technology are two key technologies that allow network operators to customize their infrastructure based on application requirements and therefore minimizing the extra capital and operational costs required for hosting new applications. In this paper, for the first time we report on design, implementation & demonstration of a novel OpenFlow based SDN unified control plane allowing seamless operation across heterogeneous state-of-the-art optical and packet transport domains. We verify and experimentally evaluate OpenFlow protocol extensions for flexible DWDM grid transport technology along with its integration with fixed DWDM grid and layer-2 packet switching.

Mutations of p53 gene in hepatocellular-carcinoma (hcc) correlate with tumor progression and patient prognosis - a study of 138 patients with unifocal hcc

The mutation spectrum of p53 gene and its biological significance were studied in 138 patients with unifocal primary hepatocellular carcinoma (HCC) in Taiwan. The p53 mutations were detected in 51 cases (37%); 36 (71%) were missense mutations. The others (29%) included mutations at the intron-exon junctions (5 cases), deletion or insertion (4 cases), nonsense mutations (4 cases), and silent mutations (2 cases). The mutation sites were scattered from exons 4 to 10, predominantly (75%) in exons 5, 7, and 8. Of these mutations, 72% were transversions, mostly G:C --> T:A change (46%); while only 28% were transitions. Mutation occurred at codon 249 only in 14 cases (10%), but accounted for 27% of the mutations. The p53 mutations correlated with allele loss of p53 locus (52% vs 17% p<0.02), alpha-fetoprotein elevation (45% vs 28%, p<0.04), and poorly differentiated HCC (46% vs 10%, p<0.0001). The p53 mutation rate was two times higher in large than in small HCC (48% vs 26%, p<0.008), and in more advanced tumor (stage 3 vs stages 1 and 2: 49% vs 21%, p<0.0007). HCC patients with mutated p53 gene had a worse outcome (5-year survival; 18% vs 38%, p<0.008). We conclude that p53 gene mutation is common in advanced HCC, occurs as a late event in HCC growth, correlates with tumor progression and aggression, and is a useful molecular prognostic parameter of HCC. The p53 mutation patterns did not correlate with HBV or HCV infection. The frequency of p53 mutations did not differ between Taiwanese patients and mainland Chinese in Taiwan. However, mutation at codon 249 was more common in Taiwanese patients (p<0.05), while mutations of other types more frequent in the mainlanders (p<0.03). Hence endogenous and exogenous factors other than aflatoxin may also play a role in p53 mutation in HCC.

Predictors of acid suppression success in patients with chronic laryngitis

BACKGROUND

Up to 50% of the patients suspected of reflux laryngitis syndrome failed to respond to acid suppression therapy. However, predictors of acid suppression success have not been determined.

METHODS

Consecutive patients with chronic laryngitis were enrolled prospectively. All the patients underwent laryngoscopy, esophagogastroduodenoscopy and 24-h multichannel intraluminal impedance and pH (MII-pH) monitoring before receiving rabeprazole 10 mg b.i.d. for 3 months. Patient was considered as a responder to acid suppression if the chief laryngeal complaint score during the last week since last interview had decreased by at least 50% after the start of therapy compared with baseline. Cox regression analysis was used to determine the independent predictors of acid suppression success.

KEY RESULTS

Of 92 patients (age 42.4 ± 14.3 years, 50 women), 42 (45.7%) responded to acid suppression after 3 months. Gastroesophageal reflux disease was defined in 22 patients, of whom 19 patients had pathological distal esophageal acid exposure and 5 were defined as erosive esophagitis. The time to response showed a significant hazard ratio for patients with increased distal esophageal acid exposure time (β: 0.93; HR: 2.55; 95% CI: 1.24-5.24; P = 0.011) and increased laryngopharyngeal bolus exposure time (BET; β: 0.96; HR: 2.61; 95% CI: 1.36-5.00; P = 0.004). The latter had the best Youden Index (0.34) and accuracy (68.5%).

CONCLUSIONS & INFERENCES

The success of acid suppression on chronic laryngitis could be predicted using reflux parameters detected by MII-pH, among which increased laryngopharyngeal BET is the best.

Surface urban heat island across 419 global big cities

Urban heat island is among the most evident aspects of human impacts on the earth system. Here we assess the diurnal and seasonal variation of surface urban heat island intensity (SUHII) defined as the surface temperature difference between urban area and suburban area measured from the MODIS. Differences in SUHII are analyzed across 419 global big cities, and we assess several potential biophysical and socio-economic driving factors. Across the big cities, we show that the average annual daytime SUHII (1.5 ± 1.2 °C) is higher than the annual nighttime SUHII (1.1 ± 0.5 °C) (P < 0.001). But no correlation is found between daytime and nighttime SUHII across big cities (P = 0.84), suggesting different driving mechanisms between day and night. The distribution of nighttime SUHII correlates positively with the difference in albedo and nighttime light between urban area and suburban area, while the distribution of daytime SUHII correlates negatively across cities with the difference of vegetation cover and activity between urban and suburban areas. Our results emphasize the key role of vegetation feedbacks in attenuating SUHII of big cities during the day, in particular during the growing season, further highlighting that increasing urban vegetation cover could be one effective way to mitigate the urban heat island effect.

New alkaloids from the seeds of Notopterygium incisum

Three new alkaloids, N-hexacosanoylanthranilic acid (1), N-octacosanoylanthranilic acid (2) and N-eicosanoyltyramine (3), along with 19 known compounds, were isolated from the seeds of Notopterygium incisum, whose rhizomes are used as a traditional Tibetan medicine. Their structures were elucidated by 1D, 2D NMR spectra and ESI-MS spectrometer evidence.

Phase I/II study to assess safety, pharmacokinetics, and efficacy of the oral MEK 1/2 inhibitor GSK1120212 (GSK212) dosed in combination with the oral BRAF inhibitor GSK2118436 (GSK436)

CRA8503

Background: In preclinical models, the BRAF/MEK inhibitor (i) combination GSK436/GSK212 has demonstrated enhanced activity against BRAF-mutant cancer cells compared to either drug alone, delayed emergence of GSK436 resistance, and prevented proliferative skin lesions attributable to BRAFi exposure. Methods: Eligible patients (pts) had BRAF V600 mutation positive solid tumors. Part 1: pharmacokinetic (PK) drug-drug interaction (DDI) study. Part 2: Dose escalation of continuous daily dosing of the combination followed by expansion cohorts; Part 3: Randomized phase II trial in untreated stage IV melanoma. Results: 45 pts have received ≥ 1 dose of GSK212 + GSK436, including 43 melanoma (all BRAFi naïve), 1 NSCLC and 1 salivary duct carcinoma. PK results of 7 pts in Part 1 showed no effect of GSK212 on single dose of GSK436. There was no clinically meaningful DDI between GSK436 and GSK212 after repeat dosing of the combination (Part 2). GSK436 was dosed 75-150 mg BID in combination with GSK212 1.0, 1.5, 2.0 mg QD. The recommended dose was 2 mg QD GSK212 in combination with 150 mg BID GSK436. At 1.5 mg GSK212, there was one DLT, a recurrent grade (G) 2 neutrophilic panniculitis. The only G4 adverse event (AE) was a sepsis-like syndrome with fever/hypotension. G3 AEs included generalized rash (n=2, 4%) and neutropenia (n=2, 4%). Skin toxicity ≥ G2 occurred in 9 (20%) pts; of these, G2 rash (n=4, 8%) and G2 macular rash (n=1, 2%). No cutaneous squamous cell carcinoma (SCC) or hyperproliferative skin lesions have occurred at any dose level. Other common G2 toxicities were pyrexia (n=5, 11%), vomiting (n=2, 4%) and fatigue (n=2, 4%). Of 16 evaluable pts in Part 2, 13 pts had PR and 3 SD for an ORR of 81% (95% CI 54.4%-96.0%) and all but 2 pts remain on study. In 10 evaluable pts who received 150 mg BID GSK436 + ≥1 mg QD GSK212, 9 pts had PR and 1 SD. Conclusions: GSK212 at 2 mg QD combines safely with GSK436 150 mg BID, no SCC thus far and decreased frequency of rash compared to previous trials of single agent GSK436 and GSK212, respectively. The preliminary anti-tumor activity warrants further investigation; the randomized phase II trial (Part 3) is accruing.

Characterization of immortalized mesenchymal stem cells derived from foetal porcine pancreas

Islet replacement therapy is limited by shortage of donor islet cells. Usage of islet cells derived from porcine pancreatic stem cells (PSCs) is currently viewed as the most promising alternative for human islet transplantation. However, PSCs are rare and have a finite proliferative lifespan. In this study, we isolated and established an immortalized mesenchymal stem cell (MSC) line derived from foetal porcine pancreas, by transfecting human telomerase reverse transcriptase (hTERT) and called these immortalized pancreatic mesenchymal stem cells (iPMSCs). The iPMSCs have been cultured for more than 80 passages and have capacity to differentiate into neurons, cardiomyocytes, germ cells and islet-like cells, analysed by morphology, RT-PCR, western blotting, immunofluorescence, immunocytochemistry and transplantation assay. Islets derived from iPMSCs reversed hyperglycaemia in streptozotocin-induced diabetic mice and secreted insulin and C-peptide in vitro. These results demonstrated that iPMSCs might provide unlimited resources for islet replacement therapy and models for functional cell differentiation.

Innovative DNA vaccine for human papillomavirus (HPV)-associated head and neck cancer

Human papillomavirus (HPV), particularly type 16, has been associated with a subset of head and neck cancers. The viral-encoded oncogenic proteins E6 and E7 represent ideal targets for immunotherapy against HPV-associated head and neck cancers. DNA vaccines have emerged as attractive approaches for immunotherapy due to its simplicity, safety, and ease of preparation. Intradermal administration of DNA vaccine via gene gun represents an efficient method to deliver DNA directly into dendritic cells for priming antigen-specific T cells. We have previously shown that a DNA vaccine encoding an invariant chain (Ii), in which the class II-associated Ii peptide (CLIP) region has been replaced by a Pan-DR-epitope (PADRE) sequence to form Ii-PADRE, is capable of generating PADRE-specific CD4+ T cells in vaccinated mice. In the current study, we hypothesize a DNA vaccine encoding Ii-PADRE linked to E6 (Ii-PADRE-E6) will further enhance E6-specific CD8+ T cell immune responses through PADRE-specific CD4+ T helper cells. We found that mice vaccinated with Ii-PADRE-E6 DNA generated comparable levels of PADRE-specific CD4+ T cell immune responses as well as significantly stronger E6-specific CD8+ T cell immune responses and antitumor effects against the lethal challenge of E6-expressing tumor compared to mice vaccinated with Ii-E6 DNA. Taken together, our data indicates that vaccination with Ii-E6 DNA with PADRE replacing the CLIP region is capable of enhancing the E6-specific CD8+ T cell immune response generated by the Ii-E6 DNA. Thus, Ii-PADRE-E6 represents a novel DNA vaccine for the treatment of HPV-associated head and neck cancer and other HPV-associated malignancies.