28 research outputs found
A Reinvestigation of Neokeronopsis Populations, Including the Description of N. asiatica nov. spec. (Ciliophora, Hypotricha)
We investigated the status of various Neokeronopsis populations, using protargol-impregnated type material, a new Chinese population, and literature data. This resulted not only in the recognition of a new species, Neokeronopsis asiatica, but also in upgrading Afrokeronopsis from subgenus to genus level. The genera Neokeronopsis and Afrokeronopsis differ mainly in the buccal depression (absent vs. present) and in the midventral cirri between proter and opisthe, which are either retained (Afrokeronopsis) or transformed into cirral anlagen (Neokeronopsis). Neokeronopsis asiatica nov. spec. differs from N. spectabilis (Kahl, 1932) by the following features: body size (~ 300 × 120 μm vs. 400 × 170 μm); posterior body end (acute with distinct indentation at site of caudal cirri vs. broadly rounded and without or indistinct indentation); posterior end of marginal rows (ending at different vs. same or similar level); dorsal kinety 1 (continuous vs. fragmented); and the size of the bases of the adoral membranelles (largest membranelles on average 18 μm vs. 29 μm wide). Improved diagnoses are provided for the family Neokeronopsidae and the genera contained therein, viz., Neokeronopsis, Afrokeronopsis, and Pattersoniella. Our study shows the importance of depositing type and voucher material in recognized repositories. Only this will allow future researchers to restudy the populations, for the sake of improved taxonomic and biogeographic knowledge
Universal isocontours for dissipative Kerr solitons
Dissipative Kerr solitons can be generated within an existence region defined on a space of normalized pumping power versus cavity-pump detuning frequency. The contours of constant soliton power and constant pulse width in this region are studied through measurement and simulation. Such isocontours impart structure to the existence region and improve understanding of soliton locking and stabilization methods. As part of the study, dimensionless, closed-form expressions for soliton power and pulse width are developed (including Raman contributions). They provide isocontours in close agreement with those from the full simulation, and, as universal expressions, can simplify the estimation of soliton properties across a wide range of systems
Promotion of Para-Chlorophenol Reduction and Extracellular Electron Transfer in an Anaerobic System at the Presence of Iron-Oxides
Anaerobic dechlorination of chlorophenols often subjects to their toxicity and recalcitrance, presenting low loading rate and poor degradation efficiency. In this study, in order to accelerate p-chlorophenol (p-CP) reduction and extracellular electron transfer in an anaerobic system, three iron-oxide nanoparticles, namely hematite, magnetite and ferrihydrite, were coupled into an anaerobic system, with the performance and underlying role of iron-oxide nanoparticles elucidated. The reductive dechlorination of p-CP was notably improved in the anaerobic systems coupled by hematite and magnetite, although ferrihydrite did not plays a positive role. Enhanced dechlorination of p-CP in hematite or magnetite coupled anaerobic system was linked to the obvious accumulation of acetate, lower oxidation–reduction potential and pH, which were beneficial for reductive dechlorination. Electron transfer could be enhanced by Fe2+/Fe3+ redox couple on the iron oxides surface formed through dissimilatory iron-reduction. This study demonstrated that the coupling of iron-oxide nanoparticles such as hematite and magnetite could be a promising alternative to the conventional anaerobic reduction process for the removal of CPs from wastewater
The hydrological change under extreme drought in the United States: Separating climate and landscape impacts
Current climate change characterized by increasing temperature has led to an increase in the intensity and frequency of extreme droughts that have more prolonged and profound ecohydrological and social impacts. By paying attention to the hydrological change before and after extreme drought and the patterns of drought recovery of ecohydrological system, it is possible to better understand the consequences of extreme drought on ecohydrological system. Both climate change and landscape change have an influence on catchment hydrological condition. The drought-related hydrological change is, therefore, the combination of changes induced by these two drivers. To further explore extreme drought impacts and the root causes of hydrological change under extreme drought events, it is necessary to separate the impact of drought-related climate change from the impact of landscape change. This study aims to characterize the variations in hydroclimatic conditions before and after extreme drought by studying the hydroclimatic movements in Budyko space, explore post-drought ecohydrological system recovery, and further separate and investigate the effects of climate and landscape change on catchment hydrological conditions. Monthly SPEI at a 12-month timescale was used to characterize and define the extreme drought events. The Budyko framework was applied to study the hydroclimatic changes of 63 basins in the United States induced by extreme drought events from 1990 to 2013 by quantifying the hydroclimatic movements in Budyko space. The climate effect on precipitation partitioning was distinguished from the landscape effect that is mainly related to vegetation response to extreme drought events. The contributions of precipitation and potential evaporation were quantified to further understand the effect of climate change which is caused by alterations of these climatic variables. To understand the effect of drought-related vegetation change on catchment precipitation partitioning, NDVI was applied to examine the response of vegetation to drought in terms of alteration in vegetation greenness and patterns of vegetation recovery. There were significant hydroclimatic changes in the basins before and after extreme drought. In post-drought period, more precipitation tended to be partitioned into evaporation in most basins. Change in streamflow was larger than the change in evaporation. 63.5% of all the basins experienced wetter conditions and more precipitation after drought. All basins gradually recovered in post-drought period, but not fully restored to their pre-drought states. The hydrological change under extreme drought was not explained by climate change alone in these basins, suggesting the existence of landscape drivers. The climate and landscape effects on precipitation partitioning could either enhance or counteract each other. The landscape drivers contributed more to change in catchment precipitation partitioning. In terms of the climatic effect that associated with the change in aridity index, climate change affects catchment precipitation partitioning by changing the precipitation and potential evaporation, among which precipitation is a more crucial climatic driver. From a vegetation-related landscape perspective, vegetation greenness reverted to pre-drought level within three years in most basins. The rapid or slow recovery, regrowth and even degradation of vegetation in post-drought period cause landscape-driven changes in catchment precipitation partitioning through directly changing vegetation transpiration and streamflow.Water Managemen
Infraciliature and Cell Division of the Little Known Freshwater Ciliate Uroleptus cf. magnificus (Kahl, 1932) Olmo, 2000 (Hypotricha, Uroleptidae), and List of Published Names in Uroleptus Ehrenberg, 1831 and Paruroleptus Wenzel, 1953
In 1988, we found a large (250–400 × 80–150 μm in protargol preparations) Uroleptus-like hypotrich in a freshwater pond in Harbin, China. We studied the morphology of non-dividers and the cell division using protargol impregnation. Since we disregarded live observations and due to the lack of a modern revision of the uroleptids, a final identification was not possible. A detailed comparison with the most similar limnetic Uroleptus-like hypotrichs and with Rigidothrix goiseri revealed that the Chinese population is very likely identical with Uroleptus magnificus [basionym Holosticha (Paruroleptus) magnificus Kahl, 1932], a very rare species possibly confined to limnetic, stagnant water bodies of the holarctic region. Besides the large size, main features of U. cf. magnificus are: (i) about 80 adoral membranelles; (ii) three or four inconspicuous transverse cirri; (iii) 5–8 dorsomarginal kineties; (iv) the oral primordium originates de novo left of the postoral midventral cirri; (v) the frontal-ventral-transverse cirri anlagen of the proter and the opisthe originate via primary primordia; (vi) the left frontal cirrus of the proter originates from the middle portion of the disorganizing parental paroral; (vii) the parental endoral becomes the undulating membrane anlage for the proter; and (viii) the frontoterminal cirri originate in the plesiomorphic manner, that is, from the rearmost anlage. A compilation reveals that 59 species, subspecies, etc. have been described in or assigned to Uroleptus and Paruroleptus, but only about 50% of them seem to be true uroleptids. Many species of this predominantly limnetic group are little known
Ultra compact and low loss multimode interferenc splitter for arbitrary power splitting
Arbitrary power splitting ratio is obtained by an 1-to-2 asymmetric multimode interference splitter. The dimension of the multimode section is less than 1.5??m ?? 3??m while the excess loss is lower than 0.15 dB.EI
A Reinvestigation of Neokeronopsis Populations, Including the Description of N. asiatica nov. spec. (Ciliophora, Hypotricha)
We investigated the status of various Neokeronopsis populations, using protargol-impregnated type material, a new Chinese population, and literature data. This resulted not only in the recognition of a new species, Neokeronopsis asiatica, but also in upgrading Afrokeronopsis from subgenus to genus level. The genera Neokeronopsis and Afrokeronopsis differ mainly in the buccal depression (absent vs. present) and in the midventral cirri between proter and opisthe, which are either retained (Afrokeronopsis) or transformed into cirral anlagen (Neokeronopsis). Neokeronopsis asiatica nov. spec. differs from N. spectabilis (Kahl, 1932) by the following features: body size (~ 300 × 120 μm vs. 400 × 170 μm); posterior body end (acute with distinct indentation at site of caudal cirri vs. broadly rounded and without or indistinct indentation); posterior end of marginal rows (ending at different vs. same or similar level); dorsal kinety 1 (continuous vs. fragmented); and the size of the bases of the adoral membranelles (largest membranelles on average 18 μm vs. 29 μm wide). Improved diagnoses are provided for the family Neokeronopsidae and the genera contained therein, viz., Neokeronopsis, Afrokeronopsis, and Pattersoniella. Our study shows the importance of depositing type and voucher material in recognized repositories. Only this will allow future researchers to restudy the populations, for the sake of improved taxonomic and biogeographic knowledge
Infraciliature and Cell Division of the Little Known Freshwater Ciliate Uroleptus cf. magnificus (Kahl, 1932) Olmo, 2000 (Hypotricha, Uroleptidae), and List of Published Names in Uroleptus Ehrenberg, 1831 and Paruroleptus Wenzel, 1953
In 1988, we found a large (250–400 × 80–150 μm in protargol preparations) Uroleptus-like hypotrich in a freshwater pond in Harbin, China. We studied the morphology of non-dividers and the cell division using protargol impregnation. Since we disregarded live observations and due to the lack of a modern revision of the uroleptids, a final identification was not possible. A detailed comparison with the most similar limnetic Uroleptus-like hypotrichs and with Rigidothrix goiseri revealed that the Chinese population is very likely identical with Uroleptus magnificus [basionym Holosticha (Paruroleptus) magnificus Kahl, 1932], a very rare species possibly confined to limnetic, stagnant water bodies of the holarctic region. Besides the large size, main features of U. cf. magnificus are: (i) about 80 adoral membranelles; (ii) three or four inconspicuous transverse cirri; (iii) 5–8 dorsomarginal kineties; (iv) the oral primordium originates de novo left of the postoral midventral cirri; (v) the frontal-ventral-transverse cirri anlagen of the proter and the opisthe originate via primary primordia; (vi) the left frontal cirrus of the proter originates from the middle portion of the disorganizing parental paroral; (vii) the parental endoral becomes the undulating membrane anlage for the proter; and (viii) the frontoterminal cirri originate in the plesiomorphic manner, that is, from the rearmost anlage. A compilation reveals that 59 species, subspecies, etc. have been described in or assigned to Uroleptus and Paruroleptus, but only about 50% of them seem to be true uroleptids. Many species of this predominantly limnetic group are little known
Low-cost silicon photonic temperature sensor using broadband light source
A silicon photonic temperature sensor based on a novel asymmetric balanced Mach-Zehnder Interferometer is proposed. This new structure enables temperature sensing using low-cost broadband light sources such as LED.EICPCI-S(ISTP)