Identification of Components of the Aggregation Pheromone of the Guam Strain of Coconut Rhinoceros Beetle,Oryctes rhinoceros,and Determination of Stereochemistry

The coconut rhinoceros beetle, Oryctes rhinoceros (Linnaeus 1758) (Coleoptera: Scarabaeidae: Dynastinae) (CRB), is endemic to tropical Asia where it damages both coconut and oil palm. A new invasion by CRB occurred on Guam in 2007 and eradication attempts failed using commonly applied Oryctes rhinoceros nudivirus (OrNV) isolates. This and subsequent invasive outbreaks were found to have been caused by a previously unrecognized haplotype, CRB-G, which appeared to be tolerant to OrNV. The male-produced aggregation pheromone of the endemic, susceptible strain of O. rhinoceros (CRB-S) was previously identified as ethyl 4-methyloctanoate. Following reports from growers that commercial lures containing this compound were not attractive to CRB-G, the aim of this work was to identify the pheromone of CRB-G. Initial collections of volatiles from virgin male and female CRB-G adults from the Solomon Islands failed to show any male- or female-specific compounds as candidate pheromone components. Only after five months were significant quantities of ethyl 4-methyloctanoate and 4-methyloctanoic acid produced by males but not by females. No other male-specific compounds could be detected, in particular methyl 4-methyloctanoate, 4-methyl-1-octanol, or 4-methyl-1-octyl acetate, compounds identified in volatiles from some other species of Oryctes. Ethyl 4-methyloctanoate elicited a strong electroantennogram response from both male and female CRB-G, but these other compounds, including 4-methyloctanoic acid, did not. The enantiomers of ethyl 4-methyloctanoate and 4-methyloctanoic acid were conveniently prepared by enzymatic resolution of the commercially-available acid, and the enantiomers of the acid, but not the ester, could be separated by gas chromatography on an enantioselective cyclodextrin phase. Using this approach, both ethyl 4-methyloctanoate and 4-methyloctanoic acid produced by male CRB-G were shown to be exclusively the (R)-enantiomers whereas previous reports had suggested male O. rhinoceros produced the (S)-enantiomers. However, re-examination of the ester and acid produced by male CRB-S from Papua New Guinea showed that these were also the (R)-enantiomers. In field trapping experiments carried out in the Solomon Islands, both racemic and ethyl (R)-4-methyloctanoate were highly attractive to both male and female CRB-G beetles. The (S)-enantiomer and the corresponding acids were only weakly attractive. The addition of racemic 4-methyloctanoic acid to ethyl 4-methyloctanoate did significantly increase attractiveness, but the addition of (R)- or (S)-4-methyloctanoic acid to the corresponding ethyl esters did not. Possible reasons for the difference in assignment of configuration of the components of the CRB pheromone are discussed along with the practical implications of these results.

     

世界建筑节是真正的全球盛会

建筑是真正全球范围的活动,全世界每年有数百万建筑得以落成。然而,一直以来,还没有一个单独的年度活动能让建筑师彼此会面,交流成果,并针对其作品和行业前景进行讨论。诚然,现在已经有一些国际活动,如威尼斯双年     

地质钻探过程中上返岩屑的组分研究

采用全俄石油钻进研究院提出的岩屑组分研究方法,分析了乌克兰顿巴斯矿区地质钻探过程中上返岩屑的组分研究结果,可为钻探冲洗液的选择提供理论依据。     

Do Hydropeaking Flows Alter Juvenile Fish Growth Rates? A Test with Juvenile Humpback Chub in the Colorado River

Riverine ecosystems have been altered in many large catchments by dam development to provide water, power, flood control and navigational benefits to humans. Conservation actions in these river ecosystems are commonly focused on minimum releases of water to downstream ecosystems. Increasingly minimum release approaches are being replaced with ‘experimental’ flows that mimic natural conditions in order to benefit riverine ecosystems. While these new policies are intuitive in their design, there is limited data of how riverine ecosystems actually respond to more natural flows. A test of more natural steady‐flow water release was compared with typical fluctuating hydropower flows in the adaptive management programme at Glen Canyon Dam, Arizona, during 2008–2011 to assess growth improvements of endangered juvenile humpback chub Gila cypha. Our results are counterintuitive and show that more natural steady flows reduced growth rates of juvenile humpback chub compared with fluctuating flows when both treatments occurred within the same year. Daily growth rates during steady flows of 2009 and 2010 were 0.05 and 0.07 mm day^?1 slower, respectively, than fluctuating flows those same years, despite similar water temperatures. Juvenile humpback chub also grew more slowly during steady flows that occurred in the same season. During the summer, juvenile humpback chub grew 0.12 and 0.16 mm day^?1 in fluctuating flow regimes in 2009 and 2010, respectively, and only 0.07 mm day^?1 in the experimental steady flow regime in 2011, despite higher water temperatures. Our results suggest that optimal conservation management policies for endangered species in regulated rivers may not always be achieved with more natural flows. Copyright © 2014 John Wiley & Sons, Ltd.     

Recipes for Spatial Statistics with Global Datasets: A Martian Case Study

The Mars Odyssey Gamma Ray Spectrometer has yielded planetary data of global extent. Such remote-sensing missions usually assign the value of a continuous-valued geospatial attribute to a uniform latitude-longitude grid of bins. Typical attributes include elemental-mass fraction, areal fraction of a mineral type, areal fraction of rocks, thermal inertia, etc. The fineness of the grid is chosen according to the spatial resolution of the orbiter and concomitant data processing. We describe methods to maximize the information extracted from both bin and regional data. Rigorous use of statistical parameters and related methods for inter- and intra- regional comparisons are also discussed. While we discuss results from the Mars Odyssey mission, the techniques we describe are applicable whenever continuous-valued attributes of a planet’s surface are characterized with bins and regions. Our goal is to distill the simplest statistical methods for regional comparisons that would be intuitively accessible to planetary scientists.     

Use of activated silica sol as a flocculant in the treatment of acid mine drainage to promote sludge stability

The most common treatment for acidic drainage is lime neutralization. The process involves neutralization and precipitation of a metal hydroxide-gypsum sludge using a flocculant, generally Percol. In the short term, the sludge is stable, but in the long term, any tendency of pH to drop can re-dissolve metal hydroxides and contaminate the surrounding area and groundwater. The use of activated silica sol, an inorganic silicate polymer used in municipal water treatment, as a replacement to Percol is investigated to improve long term stability of sludge. Silica sol is an effective flocculant, has neutralization potential, and forms metal–silica bonds more resistant to pH variation than metal hydroxides. Various mine effluents and simulated solutions were treated with lime and silica sol or Percol to pH 9–10. Results show that settling characteristics with low dosages of silica sol and Percol are similar. Leachability tests showed that the stability of the sludge improved when silica sol was used for one cycle, and after 4 cycles results were similar to Percol. Activated silica sol, therefore, has the potential to increase sludge stability in a single stage lime treatment process.     

Work stressors, role-based performance, and the moderating influence of organizational support.

As a test of the 2-dimensional model of work stressors, the present study proposed differential relationships between challenge stressors and hindrance stressors and role-based performance, which were expected to be moderated by organizational support. In a sample of 215 employees across 61 offices of a state agency, the authors obtained a positive relationship between challenge stressors and role-based performance and a negative relationship between hindrance stressors and role-based performance. In addition, organizational support moderated the relationship between challenge stressors and role-based performance but did not moderate the relationship between hindrance stressors and role-based performance. This suggests that organizations would benefit from increasing challenges in the workplace as long as they are supportive of employees and removing hindrances. Further implications for organizational theory and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Seeded growth of AlN crystals on nonpolar seeds via physical vapor transport

Seeded growth of AlN single crystals was demonstrated in an induction-heated, high-temperature reactor via a physical vapor transport (PVT) process. AlN seeds were prepared from a self-seeded boule containing large single-crystalline grains. Seeded growth was interrupted several times in order to refill the AlN powder source, and a dedicated process scheme was used to ensure epitaxial growth on the seed surface, after prior exposure to air. The growth temperatures were in the range of 2200–2300°C, and the reactor pressure was in the range of 500–900 torr of UHP-grade nitrogen during each growth run. Under these growth conditions, a seed (10 mm diameter) expanded at an angle of 45°, and a larger single crystal up to 18 mm in diameter was obtained. The as-grown surface had three facets, of which facet (1120) was smooth and featureless while the other two, (4150) and (2570), showed serrated morphologies. The double-crystal x-ray rocking curve and glow discharge mass spectroscopy analysis confirmed that the grown crystal was of high crystalline quality with low impurity incorporation.     

All-solid-state, high-power, deep-UV laser system based on cascaded sum-frequency mixing in CsLiB6O10 crystals

We report on an efficient use of CsLiB(6)O(10) (CLBO) crystals employed for an all-solid-state deep-UV laser system operated at 5 kHz. We obtained greater than 3 W of UV radiation around 242 nm by mixing the 349-nm third harmonic of a Nd:YLF laser with the tunable output from a Ti:sapphire laser in a CLBO crystal. This UV radiation was subsequently mixed with the residual 1047-nm output from the Nd:YLF laser in a second CLBO crystal. The system produced 1.5 W of deep-UV radiation at 196.3 nm, which is, to our knowledge, the highest deep-UV power below 200 nm generated in a nonlinear optical crystal. Additionally, the bandwidth of both outputs was estimated to be less than 200 MHz.     

High avidity CTLs for two self-antigens demonstrate superior in vitro and in vivo antitumor efficacy

A majority of the human tumor-associated Ags characterized to date are derived from nonmutated "self"-proteins. Little is currently understood about the nature of the self-reactive lymphocytes that recognize these Ags. We recently characterized two nonmutated tumor-associated Ags for the B16 murine melanoma: tyrosinase-related protein-2 (TRP-2) and the endogenous retroviral envelope protein, p15E. We previously reported that both TRP-2 and p15E reactive CTL could be detected in the spleens of naive animals after a single in vitro stimulation using 10(-5)-10(-6) M of the appropriate Kb-binding 9-amino acid epitope. In this report we show that the CTL found in naive animals are low avidity lymphocytes, that respond only to high concentrations of peptide in vitro. We demonstrate that titration of in vitro-stimulating peptide to limiting concentrations distinguishes qualitative differences in the lymphocyte reactivity to these two Ags between vaccinated and unvaccinated animals. We further demonstrate that in vitro expansion of CTL in either high or low concentrations of stimulating peptide generated CTL cultures with different avidities for the relevant epitopes. CTL expanded in low concentrations demonstrated higher avidity for peptide-pulsed targets and better tumor recognition, when compared to CTL generated in the presence of high concentrations of Ag. More importantly, high avidity CTL demonstrated superior in vivo antitumor activity. These results demonstrate that qualitative differences in the CTL that recognize these two self-Ags are critically important to their in vitro and in vivo anti-tumor efficacy.