1,724,154 research outputs found
Status and Hierarchy: A Framework for Understanding Stratification and Inequality in Today’s China
Full text linkA revised and shortened version of this paper is published as: Zhang, Qian Forrest. 2011. “Status and hierarchy.” Pp. 96-110 in Understanding Chinese Society. London: Routledge
White Jade Carving of Zhang Qian (Chang Ch’ien) and Sacred Pomegranate
No full textA white jade carving of Zhang Qian (Chang Ch’ien), a sage and traveller. He was an officer of the Palace guard sent by Emperor Wudi (Western Han dynasty) as ambassador to Central Asia in 126 B.C. He is credited with helping to open up the Silk Road and with bringing the pomegranate (shí liu) to China. The pomegranate is a Chinese symbol of fertility and prosperity.Shunzhi reign; Qing dynast
Data associated with the publication: Decadal-scale export of nitrogen, phosphorus, and sediment from the Susquehanna River basin, USA: Analysis and synthesis of temporal and spatial patterns
No full textFrom the study abstract: The export of nitrogen (N), phosphorus (P), and suspended sediment (SS) is a long-standing management concern for the Chesapeake Bay watershed, USA. Here we present a comprehensive evaluation of nutrient and sediment loads over the last three decades at multiple locations in the Susquehanna River basin (SRB), Chesapeake's largest tributary watershed. Sediment and nutrient riverine loadings, including both dissolved and particulate fractions, have generally declined at
all sites upstream of Conowingo Dam (non-tidal SRB outlet). Period-of-record declines in riverine yield are generally smaller than those in source input, suggesting the possibility of legacy contributions. Consistent with other watershed studies, these results reinforce the importance of considering lag time between the implementation of management actions and achievement of river quality improvement. Whereas flow-normalized loadings for particulate species have increased recently below Conowingo Reservoir, those for upstream sites have declined, thus substantiating conclusions from prior studies about decreased reservoir trapping efficiency. In regard to streamflow effects, statistically significant log-linear relationships between annual streamflow and annual constituent load suggest the dominance of hydrological control on the inter-annual variability of constituent export. Concentration-discharge relationships revealed general chemostasis and mobilization effects for dissolved and particulate species, respectively, both suggesting transport-limitation conditions. In addition to affecting annual export rates, streamflow has also modulated the relative importance of dissolved and particulate fractions, as reflected by its negative correlations with dissolved P/total P, dissolved N/total N, particulate P/SS, and total N/total P ratios. For land-use effects, period-of-record median annual yields of N, P, and SS all correlate positively with the area fraction of non-forested land but negatively with that of forested land under all hydrological conditions. Overall, this work has informed understanding with respect to four major factors affecting constituent export (i.e., source input, reservoir modulation, streamflow, and land use) and demonstrated the value of long-term river monitoring.
Note: This data archive for Zhang et al. (2016) [10.1016/j.scitotenv.2016.03.104] covers years between 1980s and 2013, and thus includes two additional years of data beyond those used in Zhang et al. (2013) [10.1016/j.scitotenv.2013.02.012]. Additionally, the applied WRTDS algorithms were based on EGRET version 2.2.0 as opposed to WRTDS version 4c in Zhang et al. (2013). The most important differences relate to the handling of edge effects and multiple samples on a single day.</p
Identifying microRNAs Involved in the Onset and Progression of Age-Related Hearing Loss
No full textAge-related hearing loss (ARHL) is a progressive sensorineural hearing loss that occurs as people get older. It is generally accepted that degeneration of the organ of Corti and atrophy of the stria vascularis in the inner ear are the two primary causes of ARHL. MicroRNAs (miRNAs), a class of short non-coding RNAs that regulate the expression of mRNA/protein targets, are important regulators of cellular senescence and aging. I examined miRNA gene expression profiles in the organ of Corti (OC) and stria vascularis (SV) of C57BL/6J and CBA/J mice at three different ages using microarray analysis, and hair cell and strial morphology and auditory function using immunocytochemistry and electrophysiology. One hundred eleven and 71 miRNAs exhibited differential expression in the OV of C57 and CBA mice, respectively, while 95 and 59 miRNAs were differentially expressed, respectively, in the SV of these mice. Downregulated miRNAs substantially outnumbered upregulated miRNAs during aging. The changes in the miRNA expression occurred well before morphological and functional changes were detected. Further experiments using quantitative real-time PCR (qPCR) and in situ hybridization showed that four separate subsets of miRNAs in the OC and SV were positively expressed in different areas in the cochlea. The changes were consistent with their presumptive roles in regulating growth and apoptosis. The potential targets of several apoptosis-related miRNAs were further explored using an apoptosis-related gene microarray technique and bioinformatic analyses. It appears that the underlying process and regulatory mechanisms of aging in the OC and SV involve repression of miRNAs important for proliferation and differentiation and enhancement of miRNAs that promote apoptosis. The present work is the first step in an effort to elucidate the roles of miRNAs and their regulatory networks in age-related degeneration of the inner ear. It lays the groundwork for future experiments that can explore whether suppression or overexpression of certain specific miRNAs can slow the onset and progression of ARHL.ProQuest Traditional Publishing Optio
Data associated with the publication: Long-term trends of nutrients and sediment from the nontidal Chesapeake watershed: an assessment of progress by river and season
No full textFrom the study abstract: To assess historical loads of nitrogen (N), phosphorus (P), and suspended sediment (SS) from the nontidal Chesapeake Bay watershed (NTCBW), we analyzed decadal seasonal trends of flow-normalized loads at the fall-line of nine major rivers that account for >90% of NTCBW flow. Evaluations of loads by season revealed N, P, and SS load magnitudes have been highest in January-March and lowest in July-September, but the temporal trends have followed similar decadal-scale patterns in all seasons, with notable exceptions. Generally, total N (TN) load has dropped since the late 1980s, but particulate nutrients and SS have risen since the mid-1990s. The majority of these rises were from Susquehanna River and relate to diminished net trapping at the Conowingo Reservoir. Substantial rises in SS were also observed, however, in other rivers. Moreover, the summed rise in particulate P load from other rivers is of similar magnitude as from Susquehanna. Dissolved nutrient loads have dropped in the upland (Piedmont and above) rivers, but risen in two small rivers in the Coastal Plain affected by lagged groundwater input. In addition, analysis of fractional contributions revealed consistent N trends across the upland watersheds. Finally, total N:total P ratios have declined in most rivers, suggesting the potential for changes in nutrient limitation. Overall, this integrated study of historical data highlights the value of maintaining long-term monitoring at multiple watershed locations
Data associated with Long-term seasonal trends of nitrogen, phosphorus, and suspended sediment load from the non-tidal Susquehanna River Basin to Chesapeake Bay
No full textFrom the study abstract: Reduction of nitrogen (N), phosphorus (P), and suspended sediment (SS) load has been a principal focus of Chesapeake Bay Watershed management for decades. To evaluate the progress of management actions in the Bay's largest tributary, the Susquehanna River, we analyzed the long-term seasonal trends of flow-normalized N, P, and SS load over the last two to three decades, both above and below the Lower Susquehanna River Reservoir System. Our results indicate that annual
and decadal-scale trends of nutrient and sediment load generally followed similar patterns in all four seasons, implying that changes in watershed function and land use had similar impacts on nutrient and sediment load at all times of the year. Above the reservoir system, the combined loads from the Marietta and Conestoga Stations indicate general trends of N, P, and SS reduction in the Susquehanna River Basin, which can most likely be attributed to a suite of management actions on point, agricultural, and stormwater sources. In contrast, upward trends of SS and particulate-associated P and N were generally observed below the Conowingo Reservoir since the mid-1990s. Our analyses suggest that (1) the reservoirs' capacity to trap these materials has been diminishing over the past two to three decades, and especially so for SS and P since the mid-1990s, and that (2) the Conowingo Reservoir has already neared its sediment storage capacity. These changes in reservoir performance will pose significant new kinds of challenges to attainment of total maximum daily load goals for the Susquehanna River Basin, and particularly if also accompanied by increases in storm frequency and intensity due to climate change. Accordingly, the reservoir issue may need to be factored into the proper establishment of regulatory load requirements and the development of watershed implementation plans.
Note: This data archive for Zhang et al. (2013) [10.1016/j.scitotenv.2013.02.012] stores data that were obtained based on the WRTDS algorithms, version 4c. This archive also stores updated and unpublished estimates in the data folder 'B. Unpublished Data, Codes, and Output' that were obtained in 2014 using longer records (~ two additional years of data) and updated codes (i.e., EGRET version 2.2.0). The most important differences relate to the handling of edge effects.</p
Data and code from: Optimizing the design of flower areas to enhance their effectiveness in supporting ground-active predators: a meta-analysis across Europe
No full textThe dataset contains the raw data (Excel file) and the R script used to conduct the statistical analyses presented in "Optimizing the design of flower areas to enhance their effectiveness in supporting ground-active predators: a meta-analysis across Europe" (Journal of Applied Ecology
Data associated with An Improved Method for Interpretation of Riverine Concentration-Discharge Relationships Indicates Long-Term Shifts in Reservoir Sediment Trapping
No full textDerived from river monitoring data, concentration-discharge (C-Q) relationships are powerful indicators of export dynamics. Proper interpretation of such relationships can be made complex, however, if the ln(C)~ln(Q) relationships are nonlinear or if the relationships change over time, season, or discharge. Methods of addressing these issues by ‘binning’ data can introduce artifacts that obscure underlying interactions among time, discharge, and season. Here we illustrate these issues and propose an alternative method that uses the regression coefficients of the recently-developed WRTDS (‘Weighted Regressions on Time, Discharge, and Season’) model for examining (C-Q) relationships in long-term, discretely-sampled data for various water-quality constituents, including their uncertainties. The method is applied to sediment concentration data from Susquehanna River at Conowingo Dam, Maryland to illustrate how the coefficients can be accessed and presented in ways that provide additional insights toward the interpretation of river water-quality data, which reaffirms the recently-documented decadal-scale decline in reservoir trapping performance
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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