Spatial knowledge deficiencies drive taxonomic and geographic selectivity in data deficiency

The uncertain threat status of species inevitably influences their focus on conservation. Just as in extinction risk, the non-randomness phenomenon related to uncertainty (also referred to as selectivity), which is a certain character cluster in some groupings, also exists in data deficiency of species&#39; knowledge. In order to illustrate this kind of non-random phenomenon and explain the uncertainties it caused, we performed a hypergeometric test on taxonomic and geographic groupings of China&#39;s spermatophyte species and quantified two factors&mdash; frequency of collections and spatial accessibility&mdash; to indicate the primary causes of spatial knowledge deficiencies. We found that selectivity in data deficiency exists both taxonomically and geographically. Fifteen of the families were more deficient than expected, which included 30.0% of species and 56.3% ranked data deficient (DD). Among these, eight families were statistically highly significant with p &lt; 0.001 and included 25.2% of species and 50.0% ranked DD. Forty-six families were less deficient than expected. With respect to floristic division, four of 29 floristic regions and subregions were more deficient than expected, and seven were less deficient than expected. Spatial autocorrelation analysis on DD species suggested an aggregated pattern of data deficiency in China (Moran&#39;s I = 0.58, z-score = 27.0, p &lt; 0.001), and these areas that contained the highest numbers of DD species also contained the highest number of species (Spearman&#39;s R2 = 0.879, p &lt; 0.001). However, the largest DD ratio had a low correlation with the richest DD spatial diversity. Moreover, we found the larger the DD ratio was, the lower the frequency of collections and the poorer the spatial accessibility would be. In the research, we showed that the uncertainties associated with DD species would alter the non-randomness in the selectivity of data deficiency and further affect the focus of conservation. Only with a full understanding of the process and mechanisms of data deficiency can we determine where and what kind of actions are necessary to improve the knowledge of plant diversity. Citation:&nbsp;Lina Zhao, Yuchang Yang, Huiyuan Liu, Zhangjian Shan, Dan Xie, Zheping Xu, Jinya Li. Spatial knowledge deficiencies drive taxonomic and geographic selectivity in data deficiency. Biological Conservation.2019,231:174-180.DOI:10.1016/j.biocon.2018.12.009</p

Prolonged membrane potential depolarization in cingulate pyramidal cells after digit amputation in adult rats

The anterior cingulate cortex (ACC) plays an important role in higher brain functions including learning, memory, and persistent pain. Long-term potentiation of excitatory synaptic transmission has been observed in the ACC after digit amputation, which might contribute to plastic changes associated with the phantom pain. Here we report a long-lasting membrane potential depolarization in ACC neurons of adult rats after digit amputation in vivo. Shortly after digit amputation of the hind paw, the membrane potential of intracellularly recorded ACC neurons quickly depolarized from ~-70 mV to ~-15 mV and then slowly repolarized. The duration of this amputation-induced depolarization was about 40 min. Intracellular staining revealed that these neurons were pyramidal neurons in the ACC. The depolarization is activity-dependent, since peripheral application of lidocaine significantly reduced it. Furthermore, the depolarization was significantly reduced by a NMDA receptor antagonist MK-801. Our results provide direct in vivo electrophysiological evidence that ACC pyramidal cells undergo rapid and prolonged depolarization after digit amputation, and the amputation-induced depolarization in ACC neurons might be associated with the synaptic mechanisms for phantom pain

Micrometer-sized point temperature sensor in Er : ZBLALiP

A new kind of Erbium-doped heavy fluoride glass Er:ZBLALiP was elaborated, and microspheres were fabricated with this fluoride glass. Thermal properties and spectroscopic properties of Er:ZBLALiP excited at 805 nm were investigated. Based on this thermalization effects between upper levels of green fluorescence in Er:ZBLALiP, we proposed an optical temperature sensing using micrometer-sized spherical cavity. The sphere temperature is scaled by the ratio of green emission intensities at 522 and 547 nm. A wide dynamic temperature ranging from 100 K to 850 K can be utilized by this type of point temperature sensor

Environmental footprint assessment of green campus from a food-water-energy nexus perspective

Universities not only can be considered as small communities due to their intensive population and their provision of complex services, but also play a vital role in the education system for global sustainable future. Thus, the environmental impacts and green operation of universities has great reference value for the design of sustainable development. In this study, we develop an environmental footprint framework based on life cycle analysis (LCA) to systematically and comprehensively understand how universities interact with the hydrologic cycle, energy resources and climate. Using Keele University in UK as an example, we further quantified the nexus and trade-offs between environmental elements including water, energy, food, waste and carbon emissions. We believe that this method will contribute to the development of footprint assessment and sustainable development, and the findings could serve as reference for policy-makers who are interested in developing green campuses

Metallic liquids and glasses : atomic order and global packing

2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Consistent model of magnetism in ferropnictides

The discovery of superconductivity in LaFeAsO introduced the ferropnictides as a major new class of superconducting compounds with critical temperatures second only to cuprates. The presence of magnetic iron makes ferropnictides radically different from cuprates. Antiferromagnetism of the parent compounds strongly suggests that superconductivity and magnetism are closely related. However, the character of magnetic interactions and spin fluctuations in ferropnictides, in spite of vigorous efforts, has until now resisted understanding within any conventional model of magnetism. Here we show that the most puzzling features can be naturally reconciled within a rather simple effective spin model with biquadratic interactions, which is consistent with electronic structure calculations. By going beyond the Heisenberg model, this description explains numerous experimentally observed properties, including the peculiarities of the spin wave spectrum, thin domain walls, crossover from first to second order phase transition under doping in some compounds, and offers new insight in the occurrence of the nematic phase above the antiferromagnetic phase transition.Comment: 5 pages, 3 figures, revtex

Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity

We use neutron scattering to study the structural and magnetic phase transitions in the iron pnictides CeFeAsO1-xFx as the system is tuned from a semimetal to a high-transition-temperature (high-Tc) superconductor through Fluorine (F) doping x. In the undoped state, CeFeAsO develops a structural lattice distortion followed by a stripe like commensurate antiferromagnetic order with decreasing temperature. With increasing Fluorine doping, the structural phase transition decreases gradually while the antiferromagnetic order is suppressed before the appearance of superconductivity, resulting an electronic phase diagram remarkably similar to that of the high-Tc copper oxides. Comparison of the structural evolution of CeFeAsO1-xFx with other Fe-based superconductors reveals that the effective electronic band width decreases systematically for materials with higher Tc. The results suggest that electron correlation effects are important for the mechanism of high-Tc superconductivity in these Fe pnictides.Comment: 19 pages, 5 figure

Characteristics comparison of optimal L-band Er-doped ASE sources in different configurations

In this paper, we investigate the 1480nm pumped L-band erbium doped fiber amplified spontaneous emission source of three major configurations: one-stage double-pass forward pump configuration, two-stage with C-band ASE injection configuration, one-stage double-pass bi-directional pump configuration. The characteristics are compared in terms of the output power, pumping conversion efficiency, bandwidth, and mean wavelength stability. It is shown that the one-stage double-pass bi-directional pump configuration has a better performance than the other two configurations

Proximity of Iron Pnictide Superconductors to a Quantum Tricritical Point

We determine the nature of the magnetic quantum critical point in the doped LaFeAsO using a set of constrained density functional calculations that provide ab initio coefficients for a Landau order parameter analysis. The system turns out to be remarkably close to a quantum tricritical point, where the nature of the phase transition changes from first to second order. We compare with the effective field theory and discuss the experimental consequences.Comment: 4 pages, 4 figure