Changes in Snow Phenology from 1979 to 2016 over the Tianshan Mountains, Central Asia

Snowmelt from the Tianshan Mountains (TS) is a major contributor to the water resources of the Central Asian region. Thus, changes in snow phenology over the TS have significant implications for regional water supplies and ecosystem services. However, the characteristics of changes in snow phenology and their influences on the climate are poorly understood throughout the entire TS due to the lack of in situ observations, limitations of optical remote sensing due to clouds, and decentralized political landscapes. Using passive microwave remote sensing snow data from 1979 to 2016 across the TS, this study investigates the spatiotemporal variations of snow phenology and their attributes and implications. The results show that the mean snow onset day (Do), snow end day (De), snow cover duration days (Dd), and maximum snow depth (SDmax) from 1979 to 2016 were the 78.2nd day of hydrological year (DOY), 222.4th DOY, 146.2 days, and 16.1 cm over the TS, respectively. Dd exhibited a spatial distribution of days with a temperature of \u3c0 \u3e°C derived from meteorological station observations. Anomalies of snow phenology displayed the regional diversities over the TS, with shortened Dd in high-altitude regions and the Fergana Valley but increased Dd in the Ili Valley and upper reaches of the Chu and Aksu Rivers. Increased SDmax was exhibited in the central part of the TS, and decreased SDmax was observed in the western and eastern parts of the TS. Changes in Dd were dominated by earlier De, which was caused by increased melt-season temperatures (Tm). Earlier De with increased accumulation of seasonal precipitation (Pa) influenced the hydrological processes in the snowmelt recharge basin, increasing runoff and earlier peak runoff in the spring, which intensified the regional water crisi

Streamflow Pattern Variations Resulting from Future Climate Change in Middle Tianshan Mountains Region in China

In arid and semi-arid regions of North West china, glacier-melt, seasonal snowmelt and rainfall are the primary sources of flow in the rivers that originate from alpine areas. Spring and summer peak flow resulting from snowmelt and rainfall, respectively, are the main characteristics of streamflow pattern. Because of the damages caused by the spring and summer peak flow, a better understanding of the streamflow pattern variation under future climate warming is crucial. To analyze the variation of streamflow pattern under climate warming, the Kaidu River and the Manasi River watersheds in northern and southern slopes of Middle Tianshan Mountains, located in Xinjiang were selected as study areas. These watersheds receive water from water sources in different proportions. A modified hydrological model was forced with metrological data from CIMP5 data set and the streamflow in Kaidu and Manasi River watersheds were simulated. The results indicate that one-peak-flow pattern is projected to turn to the two-peak-flow pattern in the Manasi River watershed in the future. The two-peak flow pattern will continue in the Kaidu River watershed, but the dominant peak flow will shift from summer to spring in future. This study provides useful information for water resources managers to take different actions to reduce damages caused by spring and summer peak flow under future climate warming

Developmental features and yields of three promising upland rice varieties in Zimbabwe

Three upland rice varieties: NERICA 1, 3 and 7 that were proved to be promising by previous trails in Zimbabwe, were selected as experimental materials to evaluate their developmental features and yields in irrigated conditions. The results indicate that plant height increased sharply first, and then slowly until the highest values that kept invariant. Tiller number per hill showed S-shaped curves which increased and reached relatively stable values first, then decreased slightly and finally increased again to produce the second time tiller. The leaf number per plant was apparently went up and down, which ascended to the peak values and then started to descend. NERICA 1 had many features which differed from NERICA 3 and NERICA 7, such as early maturing, short plant height, multiple tiller and multiple leave. It had the highest number of panicles and grains among the three varieties though it had nearly the same grain weight with NERICA 3 and NERICA 7. These results will be helpful to release these varieties in Zimbabwe.Keywords: Developmental feature, upland rice variety, yield, yield components, ZimbabweAfrican Journal of Biotechnology Vol. 12(21), pp. 3208-321

Changes in soil labile and recalcitrant carbon pools after land-use change in a semi-arid agro-pastoral ecotone in Central Asia

Soil organic matter is a heterogeneous and complex entity that consists of a diverse range of compounds. However, the responses of soil organic carbon (SOC) fractions with different biochemical stabilities to land-use change are inadequately addressed. In this study, soil samples (0-60 cm) were collected with a 10 cm interval from grassland (GS), cropland (CS), woodland (WS), and orchard (OS) using paired-site approach in a typical semi-arid agro-pastoral ecotone in the Ili River Valley, Central Asia, to: (1) clarify the vertical changes in soil labile (LPI and LPII) and recalcitrant C pools (RP) after GS conversion to CS and CS conversion to WS and OS; and to (2) evaluate the impact of land-use change on SOC stability. The results indicated that LPI stocks in topsoil (0-30 cm) and subsoil (30-60 cm) showed opposite responses to land-use change. In contrast, LPII and RP stocks in both soil layers significantly decreased after conversion of GS to CS, and significantly increased after CS afforestation. These results demonstrated that RP in subsoils could also be altered by land-use change. In general, conversion from GS to CS decreased the recalcitrance index of SOC (RISOC), which increased after conversion from CS to WS. The results implied that cultivation decreased the stability of SOC, causing the depletion of SOC stock, whereas CS conversion to WS enhanced the stability of SOC, promoting SOC sequestration. The negative correlations between RISOC, pH, and electrical conductivity (EC1:5) suggested that soil pH and salinity were potential indicators reflecting the biochemical recalcitrance of SOC. Since both soil pH and EC1:5 showed decreasing trends after conversion from CS to WS and OS, the results suggested that afforestation on CS contributed to mitigate soil salinization while promoting SOC sequestration in this semi-arid agro-pastoral ecotone

Spatial Separation of the Conformers of Methyl Vinyl Ketone

Methyl vinyl ketone (C$_4$H$_6$O) is a volatile, labile organic compound of importance in atmospheric chemistry. We prepared a molecular beam of methyl vinyl ketone with a rotational temperature of 1.2(2)~K and demonstrated the spatial separation of the \emph{s-cis} and \emph{s-trans} conformers of methyl vinyl ketone using the electrostatic deflector. The resulting sample density was $1.5(2)\times10^{8}~\text{cm}^{-3}$ for the direct beam in the laser ionization region. These conformer-selected methyl vinyl ketone samples are well suited for conformer-specific chemical reactivity studies such as in Diels-Alder cycloaddition reactions.Comment: Accepted by J. Phys. Chem. A. Manuscript: 5 pages, 3 figures; Supporting information: 3 pages, 5 figure

Self-Assembled Copper Polypyridyl Supramolecular Metallopolymer Achieving Enhanced Anticancer Efficacy

Metallopolymers, a combination of organic polymers and metal center, contain metal atoms in repeating monomers can change its dynamic and thermodynamic properties through the directionality of coordination bonds and chemical tailoring of ligands. In the past decade, self-assembled functional supramolecular metallopolymers have aroused a surge of research interest, and have demonstrated application potential in cancer therapy. In this chapter, we have summarized the progress in the rational design of biological application of different metallopolymers. Especially, a copper polypyridyl complex was found be able to self-assemble into a supramolecular metallopolymer driven by the intermolecular interactions, which could enhance the uptake in cancer cells through endocytosis, thus effectively inhibit tumor growth in vivo without damage to the major organs. This study may provide a good example to use self-assembled metallopolymer to achieve enhanced anticancer efficacy

Streamflow Forecast and Reservoir Operation Performance Assessment Under Climate Change

This study attempts to investigate potential impacts of future climate change on streamflow and reservoir operation performance in a Northern American Prairie watershed. System Dynamics is employed as an effective methodology to organize and integrate existing information available on climate change scenarios, watershed hydrologic processes, reservoir operation and water resource assessment system. The second version of the Canadian Centre for Climate Modelling and Analysis Coupled Global Climate Model is selected to generate the climate change scenarios with daily climatic data series for hydrologic modeling. Watershed-based hydrologic and reservoir water dynamics modeling focuses on dynamic processes of both streamflow generation driven by climatic conditions, and the reservoir water dynamics based on reservoir operation rules. The reliability measure describes the effectiveness of present reservoir operation rules to meet various demands which are assumed to remain constant for the next 100 years in order to focus the study on the understanding of the structure and the behaviour of the water supply. Simulation results demonstrate that future climate variation and change may bring more high-peak-streamflow occurrences and more abundant water resources. Current reservoir operation rules can provide a high reliability in drought protection and flood control

Human Migration through Bottlenecks from Southeast Asia into East Asia during Last Glacial Maximum Revealed by Y Chromosomes

Molecular anthropological studies of the populations in and around East Asia have resulted in the discovery that most of the Y-chromosome lineages of East Asians came from Southeast Asia. However, very few Southeast Asian populations had been investigated, and therefore, little was known about the purported migrations from Southeast Asia into East Asia and their roles in shaping the genetic structure of East Asian populations. Here, we present the Y-chromosome data from 1,652 individuals belonging to 47 Mon-Khmer (MK) and Hmong-Mien (HM) speaking populations that are distributed primarily across Southeast Asia and extend into East Asia. Haplogroup O3a3b-M7, which appears mainly in MK and HM, indicates a strong tie between the two groups. The short tandem repeat network of O3a3b-M7 displayed a hierarchical expansion structure (annual ring shape), with MK haplotypes being located at the original point, and the HM and the Tibeto-Burman haplotypes distributed further away from core of the network. Moreover, the East Asian dominant haplogroup O3a3c1-M117 shows a network structure similar to that of O3a3b-M7. These patterns indicate an early unidirectional diffusion from Southeast Asia into East Asia, which might have resulted from the genetic drift of East Asian ancestors carrying these two haplogroups through many small bottle-necks formed by the complicated landscape between Southeast Asia and East Asia. The ages of O3a3b-M7 and O3a3c1-M117 were estimated to be approximately 19 thousand years, followed by the emergence of the ancestors of HM lineages out of MK and the unidirectional northward migrations into East Asia

Greenhouse Gas Emissions from Cotton Field under Different Irrigation Methods and Fertilization Regimes in Arid Northwestern China

Drip irrigation is broadly extended in order to save water in the arid cotton production region of China. Biochar is thought to be a useful soil amendment to reduce greenhouse gas (GHG) emissions. Here, a field study was conducted to compare the emissions of nitrous oxide (N2O) and methane (CH4) under different irrigation methods (drip irrigation (D) and furrow irrigation (F)) and fertilization regimes (conventional fertilization (C) and conventional fertilization + biochar (B)) during the cotton growth season. The accumulated N2O emissions were significantly lower with FB, DC, and DB than with FC by 28.8%, 36.1%, and 37.6%, while accumulated CH4 uptake was 264.5%, 226.7%, and 154.2% higher with DC, DB, and FC than that with FB, respectively. Irrigation methods showed a significant effect on total global warming potential (GWP) and yield-scaled GWP (P<0.01). DC and DB showed higher cotton yield, water use efficiency (WUE), and lower yield-scaled GWP, as compared with FC and FB. This suggests that in northwestern China mulched-drip irrigation should be a better approach to increase cotton yield with depressed GHG. In addition, biochar addition increased CH4 emissions while it decreased N2O emissions

Effects of levofloxacin hydrochlordie on photosystem II activity and heterogeneity of Synechocystis sp.

Effects of LH on photosynthesis of Synechocystis sp. were investigated by a variety of in vivo chlorophyll fluorescence. O-2 evolution and the photosystem II (PSII) activity were clearly inhibited by LH. Exposure to LH increased the proportion of PSII beta and this weakened the connectivity between PS11 units and hindered excitation energy-transfer between PSII units. LH decreased the density of the active photosynthetic reaction centers, inhibited electron transport, and increased the dissipated energy flux per reaction center. The inhibitory effect of LH on Q(A)(-) reoxidation process could be divided into several stages. LH first inhibited the electron transfer from Q(A)(-) to Q(B) by weakening the connectivity between Q(A)(-) and Q(B), and PQ binding began taking part in Q(A)(-) reoxidation. At the second stage, the connectivity between Q(A)(-) and PQ pool was broken and inhibition on PQ binding occurred. At this stage, some Q(A)(-) began to be oxidized by S-2(Q(A)Q(B))(-). Finally, when the connectivity between Q(A)(-) and Q(B) and PQ was completely broken, all Q(A)(-) was oxidized through charge recombination. (C) 2009 Elsevier Ltd. All rights reserved