Effect of ferrous ion on the biological activity in a UASB reactor: mathematical modeling and verification

The effect of ferrous ion on the biological activity in a upflow anaerobic sludge blanket (UASB) reactor was studied. A mathematical model was developed and validated in order to simulate the dynamic behavior of a UASB reactor. This model took into consideration of all the biological and physicochemical reactions. The model was able to simulate the accumulation of iron in the sludge bed and its effect on the biological activity of the anaerobic sludge. A significant increase in the maximum uptake rate of methanogens and acidogens was revealed when iron was supplemented to the UASB reactor. The addition of ferrous iron induced a stable and excellent COD conversion rate. The model can be a useful tool for the prediction of process performance in the future and can be used to assist in the operation of biogas plants. The ferrous ion addition proved to enhance the biological activity of UASB sludge. Thus, the model can be used for the design of treatment plants that will take advantage of the benefits of iron addition.     

Osteoactivin fragments produced by ectodomain shedding induce MMP-3 expression via ERK pathway in mouse NIH-3T3 fibroblasts

Intact osteoactivin, a novel type I membrane glycoprotein, were shed at a dibasic motif in the juxtamembrane region in C2C12 myoblasts. Extracellular fragments were secreted into the culture media by a putative metalloprotease. Extracellular fragments of osteoactivin, but not control protein, induced matrix metalloprotease-3 (MMP-3) expression in NIH-3T3 fibroblasts. Epidermal growth factor (ERK) kinase inhibitors inhibited the osteoactivin-mediated MMP-3 expression, whereas the extracellular fragment of osteoactivin activated ERK1/2 and p38 in the mitogen-activated protein kinase pathway. Our results suggest that the extracellular fragments of osteoactivin produced by shedding act as a growth factor to induce MMP-3 expression via the ERK pathway in fibroblasts.     

Reproduction strategy of Trias verrucosa (Orchidaceae) from China

Trias, an orchid genus, was reported in this paper from China as a newly recorded genus for the first time. The genus and its new species, T. verrucosa Z. J. Liu, L. J. Chen et S. P. Lei, were described and discussed. Trias consists of 19 species ranging from Assam of India to Indonesia and Australia in the southeast via Myanmar to Deccan of India in the southwest. Its occurrence in West Yunnan of China is a further indication of phytogeographical relations between this region and the tropical Asia. This new species grows on shady rocks in forests. By observing of its biological characteristics such as phenology and blooming biology, lots of cloned ramets of generation overlap were found, but there were no fruited plants, and that clonal reproduction could repeat had nothing to do with whether the ramet bloomed or not. The flowering season of this species is from early April to early May. The opening of flowers on plants or inflorescence was irregular and the florescence of single flowers was rather short, only lasting 4–5 d, and no fruited flowers were found. Based on the detection of mating systems, no flowers of artificial self-pollination and artificial cross-pollination have fruited. Since the flowering period is just before the rainy season in this region, the ecological conditions of dryness, strong wind, low temperature and weak light during that period of time are evidently unfavorable to plant blooming, pollinating and fruiting. Apparently, the short duration and sterility of each flower would avoid the invalid energy waste in unfavorable circumstances and save the limited energy for more valid asexual reproduction so that the opportunity of multiplication in an uncertain environment would be increased to ensure the progenitive success. The P/O value of T. verrucosa is 187.4 ± 22.4, which is obviously related with the highly valid usage of its conglutinated and hard tuberous pollinarium during pollination, indicating that this species could hold the characteristic of sexual reproduction. This is an adaptation of this type of plants to the rather atrocious ecological circumstance there by its reproduction strategy of strengthening asexual reproduction and weakening sexual reproduction, and so it enables the plants to survive in this region, long-distanced from the places where its relatives dwell.     

Birth defects interstate data exchange: a battle worth fighting?

BACKGROUND: Regardless of where infants and children are delivered, diagnosed, or treated, an important aspect of population-based birth defects surveillance is ensuring the inclusion of children with birth defects in the catchment area. However, little is known as to how the lack of interstate birth defects data exchange affects program surveillance, monitoring, prevention, and referral activities. The study objectives were to determine the status of interstate birth defects data exchange agreements and to quantify statewide data on resident births occurring in nonresident states. METHODS: In 2004, surveys were distributed to all population-based birth defects programs in the United States to determine: 1) the types of interstate birth defects data exchange agreements that exist among birth defects programs, 2) perceived barriers in establishing exchange agreements, and 3) the extent to which out-of-state births affect a program's catchment area. The National Center for Health Statistics (NCHS) data for 2002 on live birth residency were used to determine the actual frequency of out-of-state live birth occurrence. RESULTS: Of the 52 states and territories that were surveyed, 65% (n = 34) responded. Approximately 21% (n = 7) of those that responded had an interstate data exchange agreement that allowed sharing of birth defects data with another state or a facility within another state. Approximately 53% (n = 18) of responding states indicated plans to develop an interstate birth defects data exchange agreement with other states, hospitals, or both. The NCHS data showed that the actual percentage of resident out-of-state live births ranged from 0.16 to 11.51. NCHS data also reveal that 78% of states would be able to capture >75% of their out-of-state births by sharing data on out-of-state births with the three neighboring states ranking highest in terms of such occurrences. CONCLUSIONS: Few states have interstate birth defects data exchange agreements, though all states have resident births occurring out of state. While suggestive, data beyond residency of live births are needed to quantify the degree to which the objectives of state-based birth defects programs are compromised. Resources exist to guide programs in establishing interstate data exchange agreements. Efforts to establish such agreements with only a few neighboring states could be a large step toward improving birth defects surveillance on a state, regional, and national level.     

Characterization of structural and optical properties of Mn2+-doped Zn2GeO4 nanorods as an efficient green phosphor for solid-state lighting

A series of Mn²⁺-doped zinc germinate ZGO:xMn²⁺ (x = 0–0.05) nanorods was synthesized successfully using a hydrothermal method. XRD revealed that crystal phases of the ZGO:xMn²⁺ were rhombohedral and in the R-3 space group. The Williamson–Hall equation was also used to explain the strain, nanocrystalline size, and stacking fault. Green LEDs were successfully fabricated by coating ZGO:Mn²⁺ nanorods onto UV-LED chips. For high color purity, CIE of the fabricated green LEDs were (0.2404, 0.5428), which made this material a promising candidate for fabrication of UV-based green LEDs.     

基于Cfku70基因失活策略构建果生刺盘孢的高效基因敲除底盘菌株

果生刺盘孢侵染危害多种植物,是重要的植物病原真菌。在一些丝状真菌中,敲除非同源末端连接修复通路的关键基因ku70或ku80可显著提高同源重组效率,进而提高靶基因置换频率。本研究从果生刺盘孢基因组鉴定到Cfku70和Cfku80两个基因,并明确了基因失活对菌株生物学表型和基因敲除效率的影响。敲除Cfku70或Cfku80不影响菌株的菌落形态、营养生长、产孢、分生孢子萌发、侵染结构发育和致病;Cfku70基因敲除还大幅提升3个测试基因的敲除效率。本研究证实Cfku70基因失活能显著提高果生刺盘孢的基因敲除效率,适宜作为高效基因敲除的底盘菌株,研究结果为通过批量敲除策略筛选新型致病因子奠定重要基础。     

Coastal zone use and migratory behaviour of the southern population of Mugil liza in Brazil

We analysed the ratios Sr:Ca and Ba:Ca in the otoliths of 55 adults of the southern population of Mugil liza in Brazil (Paraná to Rio Grande do Sul) to investigate its coastal zone use and migratory behaviour. All individual M. liza analysed had Sr:Ca and Ba:Ca values indicating that their birth was in the marine environment, which is consistent with the southern population migration to spawn in the ocean,. Juveniles exhibited at least three coastal use and recruitment strategies (contingents): the majority (89%) of M. liza juveniles migrated toward brackish water. They entered the estuary before completing the first year of life (64%) or after (25%) their first year of life. The remaining 11% did not appear to enter brackish or freshwater water as a nursery or at any point in their life cycle. Some adults returned to the estuary after spawning in the ocean but others (of both sexes) never returned to the estuary after spawning, remaining in the marine environment. The pattern of juvenile habitat use in the Brazilian southern population of M. liza seems to be recurrent throughout the extent of its distribution as a consequence of the reproductive spawning aggregation behaviour, which mixes all contingents (with marine or estuarine preferences).     

Uptake and transport of Pb across the iron plaque of waterlogged dropwort (Oenanthe javanica DC.) based on micro-XRF and XANES

Plant and Soil - Iron plaque at the soil-root interface is a key position for uptake of heavy metals by plants. Exploring iron plaque’s role in Pb uptake by edible vegetable roots aids...     

Photosynthesis supported by a chlorophyll f-dependent,entropy-driven uphill energy transfer in Halomicronema hongdechloris cells adapted to far-red light

Photosynthesis Research - The phototrophic cyanobacterium Halomicronema hongdechloris shows far-red light-induced accumulation of chlorophyll (Chl) f, but the involvement of the pigment in...