3-Hydroxy-2-butanone and the first encounter fight in the male lobster cockroach, Nauphoeta cinerea

Although agonistic behavior in the male lobster cockroach, Nauphoeta cinerea, has been known for more than 40 years, this is the first study to directly collect and quantify the emitted pheromones. In the present study, emitted volatile pheromones were collected from each male pair for 60 min during the first encounter fight and identified and quantified by gas chromatography–mass spectrometry. The major compound collected was 3-hydroxy-2-butanone (3H-2B). The strength of the attack by the dominant male was classified into three categories from weakest (C) to strongest (A). Of the 92 pairs, eight (8.7%) showed no agonistic interactions, and the amount of 3H-2B collected was 121.8±37.7 ng/male pair. In the five pairs (5.4%) displaying attack strength C, the amount of 3H-2B collected was 689.6±273.7 ng/male pair, and the attack duration was 9.6±2.4 min. In the 53 pairs (57.6%) showing attack strength B, the corresponding values were 5396.2±449.0 ng/male pair and 22.7±1.6 min, while those for the 26 pairs (28.3%) showing attack strength A were 7910.4±1120.6 ng/male pair and 24.9±2.9 min. For both attack strengths A and B, a linear relationship was found between the amount of 3H-2B collected and attack duration, suggesting that the longer the duration of the attack, the more 3H-2B was emitted. In addition, the rate of 3H-2B emission for attack strength A was significantly higher than that for attack strength B. Using Vaseline-coating, we demonstrated that, in the first encounter fight, the 3H-2B was emitted by the dominant male.     

Molecular Study of the Persistence of Infectious Human Norovirus on Food-Contact Surfaces

The aim of this study was to investigate the effect of relative humidity (RH) and temperature on norovirus (NoV) persistence as infectious particles on food-contact surfaces such as stainless steel and polyvinyl chloride (PVC). For this purpose, a new method combining enzymatic digestion with molecular beacon-based NASBA targeting the ORF1-ORF2 domain was developed to discriminate between infectious and noninfectious NoV. Stainless steel and PVC disks were contaminated with known amounts of human NoV and kept for 56 days at 7 and 20°C at high (86% ± 4%) and low (30% ± 10%) RH. NoV retained its putative infectivity for 56 days on PVC and for 49 days on stainless steel at 7°C and for 7 and 28 days, respectively, at low and high RH at 20°C on both tested surfaces. These results confirm that NoV persists in an infective state on inert surfaces for long periods of time and consequently may cause illness. The new molecular approach to detecting infectious NoV on inert surfaces may provide valuable information for evaluating environmental surface decontamination strategies.     

Carbon stocks in Swiss agricultural soils predicted by land-use,soil characteristics,and altitude

Effects of agricultural land-use and land-use change on soil organic carbon (SOC) pools play an important role in the mitigation of the global greenhouse effect. To estimate these effects, baseline SOC data for individual regions or countries are needed. The aim of this study was to quantify current SOC stocks in Swiss agricultural soils, to identify meaningful predictors for SOC, and to estimate historical SOC losses. SOC stocks in mineral soils were estimated from combined georeferenced data for land-use, topography, and profile data (n=544) from soil surveys. Mean SOC density in the layer 0–20 cm ranged between 40.6±8.9 t ha⁻¹ (±95% confidence interval (CI)) for arable land and 50.7±12.2 t ha⁻¹ for favourable permanent grassland, and in the layer 0–100 cm from 62.9±15.2 t ha⁻¹ for unfavourable grassland to 117.4±29.8 t ha⁻¹ for temporary grasslands (leys). SOC stocks in organic soils were quantified separately for intact and cultivated peatlands using data from peatland inventories and current SOC densities calculated from average peat decay rates. Organic soils account for less than 3% of the total area but store about 28% (47.2±7.3 Mt) of the total SOC stock of 170±17 Mt. Land-use type, clay content, and altitude (serving as a climate proxy for grassland soils at higher altitudes) were identified as main SOC predictors in mineral soils. Clay content explained up to 44% of the variability in SOC concentrations in the fine earth of arable soils, but was not significantly related to SOC in grassland soils at higher altitudes. SOC concentration under permanent grassland increases linearly with altitude, but because soil depth and stone content limit carbon storage in alpine grassland soils, no relationship was found between altitude and SOC stock. A preliminary estimate suggested that about 16% of the national SOC stock has been lost historically due to peatland cultivation, urbanisation, and deforestation. It seems unlikely that future changes in agricultural practices could compensate for this historical SOC loss in Swiss agricultural soils.     

The impact of non-invasive prenatal testing on anxiety in women considered at high or low risk for aneuploidy after combined first trimester screening

Objective: The aim of this study was to (1) examine the psychological impact of non-invasive prenatal testing (NIPT) in women with a high-risk (≥1 : 300) and low-risk (≤1 : 301) result on combined first trimester screening (cFTS) and (2) to examine factors influencing anxiety and decision-making in both risk populations. Method: Questionnaires and structured interviews were administered to low (n = 50) and high (n = 63) risk women at the time of NIPT blood draw (point A) and again at least 1 week after receiving their NIPT result (point B). Anxiety levels were measured at these two time points using the State–Trait Anxiety Inventory. Results: Both high-risk and low-risk cFTS groups demonstrated similar intrinsic (trait) anxiety levels (36 ± 10 vs 35 ± 10; p = 0.70). High-risk women had significantly higher levels of state anxiety at point A than low-risk women (42 ± 11 vs 36 ± 11; p < 0.01). Both groups had a statistically significant reduction (p < 0.01), to similar final levels of state anxiety at point B (30 ± 11 vs 29 ± 8; p = 0.61). Conclusion: Women receiving a high-risk result on cFTS have higher levels of state anxiety than their low-risk counterparts. Following a low-risk NIPT result, the anxiety levels in both populations are reduced to similar levels. © 2017 John Wiley & Sons, Ltd.     

Methane Emissions from Large Dams as Renewable Energy Resources: A Developing Nation Perspective

By means of a theoretical model, bootstrap resampling and data provided by the International Commission On Large Dams (ICOLD (2003) World register of dams. http://www.icold-cigb.org) we found that global large dams might annually release about 104 ± 7.2 Tg CH₄ to the atmosphere through reservoir surfaces, turbines and spillways. Engineering technologies can be implemented to avoid these emissions, and to recover the non-emitted CH₄ for power generation. The immediate benefit of recovering non-emitted CH₄ from large dams for renewable energy production is the mitigation of anthropogenic impacts like the construction of new large dams, the actual CH₄ emissions from large dams, and the use of unsustainable fossil fuels and natural gas reserves. Under the Clean Development Mechanism of the Kyoto Protocol, such technologies can be recognized as promising alternatives for human adaptations to climate change concerning sustainable power generation, particularly in developing nations owning a considerable number of large dams. In view of novel technologies to extract CH₄ from large dams, we estimate that roughly 23 ± 2.6, 2.6 ± 0.2 and 32 ± 5.1 Tg CH₄ could be used as an environmentally sound option for power generation in Brazil, China and India, respectively. For the whole world this number may increase to around 100 ± 6.9 Tg CH₄.     

Response of “Alamo” switchgrass tissue chemistry and biomass to nitrogen fertilization in West Tennessee,USA

Switchgrass (Panicum virgatum) is a perennial, warm-season grass that has been identified as a potential biofuel feedstock over a large part of North America. We examined above- and belowground responses to nitrogen fertilization in “Alamo” switchgrass grown in West Tennessee, USA. The fertilizer study included a spring and fall sampling of 5-year old switchgrass grown under annual applications of 0, 67, and 202 kg N ha^?1 (as ammonium nitrate). Fertilization changed switchgrass biomass allocation as indicated by root:shoot ratios. End-of-growing season root:shoot ratios (mean ± SE) declined significantly (P ≤ 0.05) at the highest fertilizer nitrogen treatment (2.16 ± 0.08, 2.02 ± 0.18, and 0.88 ± 0.14, respectively, at 0, 67, and 202 kg N ha^?1). Fertilization also significantly increased above- and belowground nitrogen concentrations and decreased plant C:N ratios. Data are presented for coarse live roots, fine live roots, coarse dead roots, fine dead roots, and rhizomes. At the end of the growing season, there was more carbon and nitrogen stored in belowground biomass than aboveground biomass. Fertilization impacted switchgrass tissue chemistry and biomass allocation in ways that potentially impact soil carbon cycle processes and soil carbon storage.     

Real-Time PCR Detection of Norovirus in Mussels Collected from the Bosphorus in Istanbul,Turkey

Norovirus (NoV) is recognised as one of the most common causes of foodborne infections, and shellfish are a well-documented source of this virus. The presence of NoV in shellfish has not previously been investigated in Turkey, and hence the aim of this study was to determine the frequency of human NoV genogroups I and II in mussels collected from the Bosphorus, Istanbul, Turkey. A total of 320 mussels representing 110 samples originating along the Bosphorus coast were collected from fish distributors. RNA was extracted using the RNeasy Mini Kit and real-time RT–PCR performed using primers specific for NoV genogroup I and II. Amongst the 110 samples, 5 (4.5%) were found to be positive for NoV genogroup II by SYBR Green assay; no genogroup I was detected. A positive signal was obtained by SYBR Green for NoV Genogroup II in mussels collected in October, November and December 2008, and February and July 2009. Only four out of five SYBR Green positive samples could be confirmed by the use of a NoV GII probe-based real-time RT–PCR. The average count and SD of Enterobactericaeae, E. coli and sulphide reductase anaerobic bacteria in PCR positive mussels were 3.56 log ± 0.96 log, 2.32 log ± 0.77 log and 1.70 log ± 0.56 log, respectively. This study shows that NoV Genogroup II is present in mussels collected from the Bosphorus, Istanbul, and may constitute a risk to human health.     

挂膜方法对生物膜特性及生化尾水深度处理的影响

为探索低浓度生化尾水生物深度处理的快速挂膜方法,采用4种方法（投加壳聚糖法、投加铁离子法、接种排泥法和自然挂膜法）进行挂膜,考察其对生物膜主要特性（生物膜量MLSS、胞外聚合物（EPS））和废水处理效果的影响.结果表明：在挂膜期间,投加壳聚糖法有利于生物膜量、EPS迅速增加,两者平均含量达到4种方法中的最大值,分别为（9.26 ±3.30） mg/cm³和（42.51 ±33.49） mg/（gSS）,但其生物膜活性f值最低,污染物的去除效果不是最佳;投加铁离子成膜时,生物膜特性稳定,活性高,污染物去除效果最佳,COD_Cr、NH₄⁺-N、TP去除率分别较快稳定在（66.13 ±2.30）%、（92.03 ±7.72）%和（62.75 ±4.41）%;接种排泥法的生物膜量、EPS均含量、污染物去除效果比投加壳聚糖、铁离子法稍低;自然挂膜法前期对污染物去除率低,稳定时间较长,除TP外,COD_Cr、NH₄⁺-N去除率在挂膜后期与投加壳聚糖法、接种排泥法相差不大.综合地看,投加铁离子法,虽然生物膜量、EPS含量略低于投加壳聚糖法,但生物膜活性高、污染去除效果好,是低浓度尾水挂膜的最佳方法.     

Anatomic and acoustic sexual dimorphism in the sound emission system of Phoenicoprocta capistrata (Lepidoptera: Arctiidae)

Both sexes of Phoenicoprocta capistrata have functional tymbals. The scanning electron microscopy revealed differences in the morphology of these organs in males and females. Male tymbals have a well-developed striated band, constituted by 21 ± 2 regularly arranged striae whereas female tymbals lack a striated band. This type of sexual dimorphism is rare in Arctiidae. The recording of the sound produced by moths held by the wings revealed that while males produced trains of pulses organized in modulation cycles, females produced clicks at low repetition rate following very irregular patterns. Statistically, there are differences between sexes in terms of the duration of pulses, which were 355 ± 24 μs in the case of males and 289 ± 29 μs for females. The spectral characteristics of the pulses also show sexual dimorphism. Male pulses are more tuned (Q ₁₀ = 5.2 ± 0.5) than female pulses (Q ₁₀ = 2.7 ± 0.5) and have a higher best frequency (42 ± 1 kHz vs. 29 ± 2 kHz). To our knowledge, this is the first report on an arctiid moth showing sexual dimorphism in tymbal’s anatomy that leads to a best frequency dimorphism. Males produce sound at mating attempts. The sounds recorded during mating are modulation cycles with the same spectral characteristics as those recorded when males are held by the wings. The morphological and acoustic features of female tymbals could indicate a process of degeneration and adaptation to conditions under which the emission of complex patterns is not necessary. Frank Coro no longer works at Universidad de La Habana.     

Studies on the use of power ultrasound in solid–liquid myrobalan extraction process

Focus on eco-friendly processing techniques makes vegetable tanning a viable option in leather processing and establishes the subsequent need for the more efficient methods of extraction in tannin manufacture. Application of ultrasound has been tried in the extraction of tannins from myrobalan nuts in order to improve the extraction efficiency, to perform the extraction under milder process conditions and to reduce the process time. The influence of process parameters such as ultrasonic output power, time and temperature has been studied. Scale-up trials and the use of ultrasound in pulse mode have also been attempted. The results show that a three- to fivefold improvement is possible with ultrasonic output from 20 to 100 W. Extraction efficiency has been calculated from the maximum extractable materials from myrobalan nuts. Extraction efficiency is found to be 90% for ultrasound, 100 W without external heating as compared to 77% for control process at 70 °C for 4 h. Therefore, ultrasound could be employed even dispensing with provision for temperature controls. The use of ultrasound in pulse mode offered 70% extraction efficiency of continuous mode. Scale-up trials indicate that there exists an optimum ultrasonic output power depending on the amount of nuts used, to achieve better extraction efficiency. The effectiveness of ultrasonically extracted tannin solution has also been tested in the tanning process for its applicability. The degree of tanning efficacy has been assessed by shrinkage temperature measurement. The results indicate that ultrasonically extracted tannin solution is suitable for tanning process. Therefore, application of ultrasound in tannin extract manufacture is a viable option with added advantages.     

Application of ecosystem health cost-effect analysis in eco-planning in Guangzhou City,China

Ecosystem health has been a focal point and research frontier of applied ecology in recent years, increasingly used in urban ecological studies. To quantify the effect of ecological improvement from eco-planning, an ecosystem health assessment method is used in eco-planning evaluation and decision support in the urban eco-planning research of Guangzhou City of China. Based on features of an urban ecosystem, five factors such as vigor, organizational structure, resilience, ability to maintain ecosystem service, and influence on people’s health were selected to develop the assessment indicator system. Then, to evaluate the validity of planning measures, a cost-effect analysis of the different scenarios on eco-planning was made, taking investment of the planned projects as the cost and ecosystem health state after implementing the scenarios as the effect. To establish priority of all the proposed planning schemes or countermeasures, variation of the ecosystem health state was evaluated when the investment of eco-environmental construction projects changes by ±10%, ±20% and ±50%, respectively. Thus, the order of importance of eco-environment construction projects to the urban ecosystem health state can be worked out, providing a reference for prioritizing the implementation of such urban eco-environmental projects. The study proved the trial value of an ecosystem health evaluation method in urban eco-planning research. Translated from China Population, Resources and Environment, 2005, 15(5): 126–130 [译自: 中国人口资源与环境]     

Cerumen of Australian stingless bees (<Emphasis Type="Italic">Tetragonula carbonaria</Emphasis>): gas chromatography-mass spectrometry fingerprints and potential anti-inflammatory properties

Cerumen, or propolis, is a mixture of plant resins enriched with bee secretions. In Australia, stingless bees are important pollinators that use cerumen for nest construction and possibly for colony’s health. While extensive research attests to the therapeutic properties of honeybee (Apis mellifera) propolis, the biological and medicinal properties of Australian stingless bee cerumen are largely unknown. In this study, the chemical and biological properties of polar extracts of cerumen from Tetragonula carbonaria in South East Queensland, Australia were investigated using gas chromatography-mass spectrometry (GC-MS) analyses and in vitro 5-lipoxygenase (5-LOX) cell-free assays. Extracts were tested against comparative (commercial tincture of A. mellifera propolis) and positive controls (Trolox and gallic acid). Distinct GC-MS fingerprints of a mixed diterpenic profile typical of native bee cerumen were obtained with pimaric acid (6.31 ± 0.97%, w/w), isopimaric acid (12.23 ± 3.03%, w/w), and gallic acid (5.79 ± 0.81%, w/w) tentatively identified as useful chemical markers. Characteristic flavonoids and prenylated phenolics found in honeybee propolis were absent. Cerumen extracts from T. carbonaria inhibited activity of 5-LOX, an enzyme known to catalyse production of proinflammatory mediators (IC₅₀ 19.97 ± 2.67 μg/ml, mean ± SEM, n = 4). Extracts had similar potency to Trolox (IC₅₀ 12.78 ± 1.82 μg/ml), but were less potent than honeybee propolis (IC₅₀ 5.90 ± 0.62 μg/ml) or gallic acid (IC₅₀ 5.62 ± 0.35 μg/ml, P < 0.001). These findings warrant further investigation of the ecological and medicinal properties of this stingless bee cerumen, which may herald a commercial potential for the Australian beekeeping industry.     

Assessment and Evaluation of an Integrated Hybrid Anaerobic–Aerobic Sewage Treatment System for the Removal of Enteric Viruses

The capability of a cost-effective and a small size decentralized pilot wastewater treatment plant (WWTP) to remove enteric viruses such as rotavirus, norovirus genogroup I (GGI), norovirus genogroup II (GGII), Hepatitis E virus (HEV), and adenovirus was studied. This pilot plant is an integrated hybrid anaerobic/aerobic setup which consisted of anaerobic sludge blanket (UASB), biological aerated filter (BAF), and inclined plate settler (IPS). Both the UASB and BAF are packed with a non-woven polyester fabric (NWPF). Results indicated that the overall log₁₀ reductions of enteric viruses’ genome copies through the whole system were 3.1 ± 1, 3.3 ± 0.5, and 2.6 ± 0.9 log₁₀ for rotavirus, norovirus GGI, and adenovirus, respectively. Reduction efficiency for both norovirus GGII and HEV after the different treatment steps could not be calculated because there were no significant numbers of positive samples for both viruses. The overall reduction of rotavirus infectious units through the whole system was 2.2 ± 0.8 log₁₀ reduction which is very close to the overall log₁₀ reduction of adenovirus infectious units through the whole system which was 2.1 ± 0.8 log₁₀ reduction. There was no considerable difference in the removal efficiency for different rotavirus G and P types. Adenovirus 41 was the only type detected in the all positive samples. Although the pilot WWTP investigated is cost effective, has a small footprint, does not need a long distance network pipes, and easy to operate, its efficiency to remove enteric viruses is comparable with the conventional centralized WWTPs.     

Evaluation of ecological design strategies in traditional houses in Diyarbakir,Turkey

This study focuses on the ecological design between traditional Diyarbak?r houses and their physical environment (topography and climate) and structural environment (building form, spatial organization, material, landscape and planting, and technical infrastructure). The basic principle was to identify the criteria that would use natural energy sources and provide the most benefit to the inhabitants. The influence of different seasons on thermal perception was investigated. The average temperature differences between the outdoor and indoor environment of the houses were 7 °C in winter, 6 °C in summer and ±2 °C in spring and autumn. Consequently, this paper discusses ecological design solutions used in traditional houses and their applicability to modern buildings and recognizes that architecture should coexist and maintain harmony with nature.     

Quantification of net primary production of Chinese forest ecosystems with spatial statistical approaches

Net primary production (NPP) of terrestrial ecosystems provides food, fiber, construction materials, and energy to humans. Its demand is likely to increase substantially in this century due to rising population and biofuel uses. Assessing national forest NPP is of importance to best use forest resources in China. To date, most estimates of NPP are based on process-based ecosystem modeling, forestry inventory, and satellite observations. There are little efforts in using spatial statistical approaches while large datasets of in-situ observed NPP are available for Chinese forest ecosystems. Here we use the surveyed forest NPP and ecological data at 1,266 sites, the data of satellite forest coverage, and the information of climate and topography to estimate Chinese forest NPP and their associated uncertainties with two geospatial statistical approaches. We estimate that the Chinese forest and woodland ecosystems have total NPP of 1,325 ± 102 and 1,258 ± 186 Tg C year⁻¹ in 1.57 million km² forests with a regression method and a kriging method, respectively. These estimates are higher than the satellite-based estimate of 1,034 Tg C year⁻¹ and almost double the estimate of 778 Tg C year⁻¹ using a process-based terrestrial ecosystem model. Cross-validation suggests that the estimates with the kriging method are more accurate. Our developed geospatial statistical models could be alternative tools to provide national-level NPP estimates to better use Chinese forest resources.     

Greenhouse gas emissions in restored secondary tropical peat swamp forests

Restoration of deforested and drained tropical peat swamp forests is globally relevant in the context of reducing emissions from deforestation and forest degradation. The seasonal flux of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) in a restoration concession in Central Kalimantan, Indonesia, was measured in the two contrasting land covers: shrubs and secondary forests growing on peatlands. We found that land covers had high, but insignificantly different, soil carbon stocks of 949?+?56 and 1126?+?147 Mg ha^?1, respectively. The mean annual CO₂ flux from the soil of shrub areas was 52.4?±?4.1 Mg ha^?1 year^?1, and from secondary peat swamp forests was 42.9?±?3.6 Mg ha^?1 year^?1. The significant difference in mean soil temperature in the shrubs (31.2 °C) and secondary peat swamp forests (26.3 °C) was responsible for the difference in total CO₂ fluxes of these sites. We also found the mean annual total soil respiration was almost equally partitioned between heterotrophic respiration (20.8?+?1.3 Mg ha^?1 year^?1) and autotrophic respiration (22.6?+?1.5 Mg ha^?1 year^?1). Lowered ground water level up to ??40 cm in both land covers caused the increase of CO₂ fluxes to 40–75%. These numbers contribute to the provision of emission factors for rewetted organic soils required in the national reporting using the 2013 Supplement of the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for wetlands as part of the obligation under the United Nations Framework Convention on Climate Change (UNFCCC).

     

酵母菌降解胞外聚合物提升剩余活性污泥的脱水性能

剩余污泥的脱水性能直接影响到污泥处置的效果和成本,提升污泥脱水性是污泥减量化的重要途径.本研究提出利用复合酵母菌群降解剩余污泥胞外聚合物(EPS)来提升污泥脱水性能的方法.首先评价了复合酵母菌群对灭菌后EPS中各组分的降解效果;继而将混合酵母细胞接入剩余污泥中进行曝气,考察了酵母菌对污泥脱水性的提升效能.研究结果表明,酵母菌对提取的EPS中蛋白质、多糖和核酸的降解效果明显,振荡培养72 h内最多分别降低了(60. 43±2. 73)%、(18. 94±2. 39)%和(48. 30±3. 37)%.向2 L剩余污泥中接入1. 5 g混合酵母菌湿菌体进行曝气,24 h后污泥的毛细吸水时间(CST)下降了(17. 19±1. 16)%,比对照组多下降了(7. 03±1. 35)%;与此同时污泥中EPS总量比对照污泥多下降了(17. 46±3. 91)%,表明酵母菌可以通过原位降解污泥中EPS来提高污泥的脱水性能.     

<Emphasis Type="SmallCaps">l</Emphasis>-5-hydroxytryptophan resets the circadian locomotor activity rhythm of the nocturnal Indian pygmy field mouse, <Emphasis Type="Italic">Mus terricolor</Emphasis>

We report that l-5-hydroxytryptophan (5-HTP), a serotonin precursor, resets the overt circadian rhythm in the Indian pygmy field mouse, Mus terricolor, in a phase- and dose-dependent manner. We used wheel running to assess phase shifts in the free-running locomotor activity rhythm. Following entrainment to a 12:12 h light–dark cycle, 5-HTP (100 mg/kg in saline) was intraperitoneally administered in complete darkness at circadian time (CT)s 0, 3, 6, 9, 12, 15, 18, and 21, and the ensuing phase shifts in the locomotor activity rhythm were calculated. The results show that 5-HTP differentially shifts the phase of the rhythm, causing phase advances from CT 0 to CT 12 and phase delays from CT 12 to CT 21. Maximum advance phase shift was at CT 6 (1.18 ± 0.37 h) and maximum delay was at CT 18 (−2.36 ± 0.56 h). No extended dead zone is apparent. Vehicle (saline) at any CT did not evoke a significant phase shift. Investigations with different doses (10, 50, 100, and 200 mg/kg) of 5-HTP revealed that the phase resetting effect is dose-dependent. The shape of the phase–response curve (PRC) has a strong similarity to PRCs obtained using some serotonergic agents. There was no significant increase in wheel-running activity after 5-HTP injection, ruling out behavioral arousal-dependent shifts. This suggests that this phase resetting does not completely depend on feedback of the overt rhythmic behavior on the circadian clock. A mechanistic explanation of these shifts is currently lacking.     

Development and characterization of microwave composite cladding

The development of cladding through microwave radiation is recently explored and very few, initial studies were reported elsewhere. In order to explore more viability of process, (EWAC (Ni based) + 20% Cr₂₃C₆ powder) composite cladding has been developed on substrate austenitic stainless steel (SS-316). The experiments were conducted in domestic microwave oven and the clad of thickness, approximate 500 m has been developed by the exposure of microwave radiation at frequency 2.45 GHz for duration of 360 s. Typical clads cross sections of composite clads showed good metallurgical bonding with the substrate by partial dilution. The back scattered electron image of clad cross section showed the reinforced chromium carbide (Cr₂₃C₆) particles are uniformly distributed and well embedded in the Ni based matrix. The developed clad is free from visible solidification cracking and has significantly less porosity which is of the order of 0.90%. The XRD pattern of the developed clad showed the presence of FeNi₃, NiSi and Cr₂₃C₆ phases. The average Vicker's microhardness of developed clad was observed as 425 ± 140 Hv.     

Effects of irrigation,fertilization and crop straw management on nitrous oxide and nitric oxide emissions from a wheat–maize rotation field in northern China

One-year winter wheat–summer maize rotation is the most popular double cropping system in north-central China, and this highly productive system is an important source of nitrous oxide (N₂O) and nitric oxide (NO) emissions due to the high fertilizer N and irrigation water inputs. To sustain the high crop production and mitigate the detrimental impacts of N₂O and NO emissions, improved management practices are extensively applied. The aim of this study is therefore to evaluate the effects of an improved management practice of irrigation, fertilization and crop straw on grain yield and N₂O and NO emissions for a wheat–maize rotation field in northern China. Using automated and manual chamber measuring systems, we monitored N₂O and NO fluxes for the conventional (CT, 2007–2008), improved (IT, 2007–2008), straw-amended (WS, 2008–2009), straw-not-amended (NS, 2008–2009), and no N-fertilizer treatments (WS–NN, 2008–2009), respectively, for one rotation-year. The grain yields were determined for CT and IT for three rotation-years (2005–2008) and for WS, NS and WS–NN for one rotation-year (2008–2009). The improved management of irrigation and fertilization reduced the annual N fertilization rate and irrigation amount by 17% and 30%, respectively; increased the maize yield by 7–14%; and significantly decreased the N₂O and NO emissions by 7% (p < 0.05) and 29% (p < 0.01), respectively. The incorporation of wheat straw increased the cumulative N₂O and NO emissions in the following maize season by 58% (p < 0.01) and 13%, respectively, whereas the effects of maize straw application were not remarkable. The N₂O and NO emission factors of applied N were 2.32 ± 2.32% and 0.42 ± 1.69% for wheat straw and 0.67 ± 0.23% and 0.54 ± 0.15% for chemical N-fertilizers, respectively. Compared to conventional management practices using high application rates of irrigation water and chemical N-fertilizer as well as the field burning of crop straw, the improved management strategy presented here has obvious environmentally positive effects on grain yield and mitigation of N₂O and NO emissions.