Contributors:Weicai Wang, Yang Gao, Pablo Iribarren Anacona, Yanbin Lei, Yang Xiang, Guoqing Zhang, Shenghai Li, Anxin Lu
Glacial lake outburst floods (GLOFs) have recently become one of the primary natural hazards in the Himalayas. There is therefore an urgent need to assess GLOF hazards in the region. Cirenmaco, a moraine-dammed lake located in the upstream portion of Zhangzangbo valley, Central Himalayas, has received public attention after its damaging 1981 outburst flood. Here, by combining remote sensing methods, bathymetric survey and 2D hydraulic modeling, we assessed the hazard posed by Cirenmaco in its current status. Inter-annual variation of Cirenmaco lake area indicates a rapid lake expansion from 0.10±0.08km2 in 1988 to 0.39±0.04km2 in 2013. Bathymetric survey shows the maximum water depth of the lake in 2012 was 115±2m and the lake volume was calculated to be 1.8×107m3. Field geomorphic analysis shows that Cirenmaco glacial lake is prone to GLOFs as mass movements and ice and snow avalanches can impact the lake and the melting of the dead ice in the moraine can lower the dam level. HEC-RAS 2D model was then used to simulate moraine dam failure of the Cirenmaco and assess GLOF impacts downstream. Reconstruction of Cirenmaco 1981 GLOF shows that HEC-RAS can produce reasonable flood extent and water depth, thus demonstrate its ability to effectively model complex GLOFs. GLOF modeling results presented can be used as a basis for the implementation of disaster prevention and mitigation measures. As a case study, this work shows how we can integrate different methods to GLOF hazard assessment.
Contributors:Qingrui Xu, Yu Cao, Xi Li, Lin Liu, Shishang Qin, Yuhao Wang, Yi Cao, Hui Xu, Dairong Qiao
Intracellular α-amylase was a special glycoside hydrolase in the cytoplasm. We cloned and expressed an intracellular α-amylase, Amy, from Paenibacillus sp. SSG-1. The recombinant enzyme was purified by metal-affinity chromatography, exhibited a molecular mass of 71.7 kDa. Amy exhibited unexpectedly sequence similarity and evolutionary relationships with alpha-glucanotransferase. The docked results of Amy with maltose showed it had similar catalytic residues with α-amylase and glucanotransferase. The substrate specificity experiment showed that Amy could hydrolyze typical substrates into glucose and maltose. It was noteworthy that Amy showed the catalytic capacity of cyclomaltodextrinase and pullulanase. Meanwhile, Amy could transfer sugar molecules and form maltotetraose upon the hydrolysis of substrates. These results indicated that Amy was a novel intracellular α-amylase with distinct catalytic ability characteristics of hydrolyzing glycogen/cyclodextrin/pullulan and transglycosylation. We deduced that Amy may play an important role in utilizing maltooligosaccharides that released from extracellular α-glucan or storage α-glucan (glycogen) in Paenibacillus sp. SSG-1.
Contributors:Cristian A. Kaufmann, Daniel J. Rafuse, Mariela E. González, María C. Álvarez, Agustina Massigoge, Nahuel A. Scheifler, María A. Gutiérrez
Inspired by the early fieldwork of G. Haynes with large sized predators in wilderness areas, the following paper presents data on bone damage patterns in a sample of guanacos killed by one of the largest predators in South America, the puma (Puma concolor, Felidae, Carnivora). We describe the bone modification pattern on the carcasses, including skeletal part representation, bone fractures, and tooth marks. Also, tooth mark modifications on bones collected from a puma enclosure at a local zoo were analyzed. Our results indicate a light modification of guanaco carcass by puma; bone damages located mainly in the upper portions of rear and forelimbs, rib cage, and scapular and pelvic girdles; and the presence of a low percentage of fractured bones. Scores, pits, and punctures are the best represented tooth marks. On average, punctures are 3.5–5 mm in diameter, although larger tooth impressions are observed. The light consumption of guanaco by the puma would provide a potential source for scavenging by other carnivores and humans.
Contributors:María José Presno, Manuel Landajo, Paula Fernández González
This paper studies stochastic convergence of per capita CO2 emissions in 28 OECD countries for the 1901–2009 period. The analysis is carried out at two aggregation levels: first for the whole set of countries (joint analysis) and then separately for developed and developing states (group analysis). A powerful time series methodology - adapted to a nonlinear framework that allows for quadratic trends with possibly smooth transition between regimes - is applied. This approach provides more robust conclusions in convergence path analysis, enabling (a) robust detection of the presence, and if so, the number of changes in the level and/or slope of the trend of the series; (b) inferences on stationarity of relative per capita CO2 emissions, conditionally on the presence of breaks and smooth transitions between regimes; and (c) estimation of change locations in the convergence paths. Finally, as stochastic convergence is attained when both stationarity around a trend and β-convergence simultaneously hold, the linear approach proposed by Tomljanovich and Vogelsang (2002) is extended in order to allow for more general, quadratic models. Overall, joint analysis finds some evidence of stochastic convergence in per capita CO2 emissions. Some dispersion in terms of β-convergence is detected by the group analysis, particularly among developed countries. This is in accordance with per capita GDP not being the sole determinant of convergence in emissions, with factors like search for more efficient technologies, fossil fuel substitution, innovation, and possibly industry outsourcing, also having a crucial role.
Cytokinesis is an essential event in canonical cell division. In multicellular organisms, cells must divide in the context of neighboring cells in intact tissues. Recent studies have shown that tissue architecture can regulate the dynamics of and molecular requirements for cytokinesis. On the other hand, regulated cytokinesis failure occurs in, and is required for the proper function of, certain cell types and tissues including cardiomyocytes, hepatocytes, and germ lines. One way to build our understanding of cytokinesis in diverse cell types is to visualize cytokinesis in intact tissues. The nematode Caenorhabditis elegans is a powerful system for such inquiries due to the well-characterized, invariant lineage of each of its cells, the ease of genomic modifications including tagging proteins, and many more advantages. The clear cuticle of C. elegans allows for live imaging of intact tissues; however, the worm's motility can confound imaging. Here we introduce two C. elegans tissues, an epithelial tissue and the germ line, both excellent systems for the study of cytokinesis in the context of an intact animal. Additionally, we present three protocols for overcoming the challenges of live imaging in C. elegans.
Contributors:M. Fortier, S. Celton-Morizur, C. Desdouets
Polyploidy, the state of having greater than a diploid DNA content (tetraploid, octoploid, etc.) is a characteristic feature of mammalian hepatocytes and accompanies late fetal development and postnatal maturation of the liver. During the weaning period, diploid hepatocytes can engage either into normal cell division cycle giving rise to two diploid hepatocytes or follow a scheduled division program characterized by incomplete cytokinesis. In that case, diploid hepatocytes undergo mitosis, but do not form a contractile ring. Indeed, cleavage-plane specification is never established, because of the deficiencies of actin cytoskeleton reorganization. Furthermore, microtubules fail both to contact the cortex and to deliver their molecular signal, preventing localization and activation of RhoA. Therefore, cytokinesis aborts and a binucleate tetraploid liver cell is generated, which subsequently plays a pivotal role in liver progressive polyploidization. In this chapter, we describe detailed protocols to monitor hepatocyte proliferation and cytokinesis process by in situ and dynamic ex vivo approaches.
Contributors:Claude J. Bajada, Hamied A. Haroon, Hojjatollah Azadbakht, Geoff J.M. Parker, Matthew A. Lambon Ralph, Lauren L. Cloutman
Temporal lobe networks are associated with multiple cognitive domains. Despite an upsurge of interest in connectional neuroanatomy, the terminations of the main fibre tracts in the human brain are yet to be mapped. This information is essential given that neurological, neuroanatomical and computational accounts expect neural functions to be strongly shaped by the pattern of white-matter connections. This paper uses a probabilistic tractography approach to identify the main cortical areas that contribute to the major temporal lobe tracts. In order to associate the tract terminations to known functional domains of the temporal lobe, eight automated meta-analyses were performed using the Neurosynth database. Overlaps between the functional regions highlighted by the meta-analyses and the termination maps were identified in order to investigate the functional importance of the tracts of the temporal lobe. The termination maps are made available in the Supplementary Materials of this article for use by researchers in the field.
Contributors:L. Giammattei, N. Penet, F. Parker, M. Messerer
Spinal ependymomas are predominantly slow-growing lesions constituting approximately 30–88% of primary spinal intramedullary tumors. They usually present as circumscribed lesions, with regular margins and a clear surgical plane. Gross-total resection is often feasible and potentially curative but neurosurgeons should keep in mind that the ultimate goal of surgery is the preservation of spinal cord function. We present the surgical technique to safely resect an intramedullary ependymoma using a posterior median sulcus approach. A brief description of current management of this pathology is also presented.
Soluble receptor for advanced glycation end products (sRAGE), a natural inhibitor of RAGE, is considered to be a putative therapeutic molecule for a variety of diseases and a biomarker for certain conditions. To further study the function of sRAGE, recombinant rat sRAGE (rrsRAGE) was expressed and produced in a eukaryotic system. The open reading frame of rat sRAGE was cloned downstream of the methanol-inducible alcohol oxidase promoter of pPICZαA vector, and Pichia pastoris strain X-33 was used as the host strain. The expression of rrsRAGE was achieved by fermentation in a 15-L bioreactor and the resulting fermentation broth was subjected to purification on a cation exchange chromatography column. The purification of rrsRAGE reached 95% after size exclusion chromatography(SEC). The bioactivity of the purified protein was confirmed in a SH-SY5Y cell proliferation assay. The biological function of the purified rrsRAGE protein rat CCl4-induced model was then examined. Treatment with rrsRAGE resulted in significantly lower liver fibrosis and lower serum level of ALT, suggesting that sRAGE prevent liver from injury and fibrosis. In conclusion, we achieved high-efficiency production of bioactive rrsRAGE in Pichia pastoris.