Status of the DIII-D 110 GHz ECH system

The DIII-D program is presently commissioning the first NM gyrotron of a planned 3 MW, I 10 GHz electron cyclotron heating (ECH) system for off-axis electron heating and current drive. Advanced tokamak (AT) research in DIII-D and other tokamaks requires the ability to control the current density profile. ECH offers the ability to localize the heating and driven current in a controllable manner and is not dependent upon, the local plasma conditions, so it appears to be an ideal tool for AT research. The planned rf sources for the DIII-D system are I MW state-of-the-art internal mode-converter gyrotrons, with one gyrotron being manufactured by GYCOM, a Russian company, and two gyrotrons being manufactured by CPI (formerly Varian). The GYCOM gyrotron has been tested at the factory to 960 kW, 2 seconds and has been shipped to GA where it is now undergoing initial checkout and testing. The first CPI gyrotron has been assembled and factory tested to 530 kW, 2 seconds and 350 1352 kW, 10 seconds. Both the GYCOM and CPI gyrotrons are limited in pulse length at full power by thermal limits on the output window. The second CPI gyrotron is expected to be ready for testing in April 1996. This paper will report on the initial experiences of using the GYCOM I MW, 110 GHz internal mode- converter gyrotron, at General Atomics, and the observed effects the ECRH power has on the DIII-D plasma

Insect Eggs Can Enhance Wound Response in Plants: A Study System of Tomato Solanum lycopersicum L. and Helicoverpa zea Boddie

Insect oviposition on plants frequently precedes herbivory. Accumulating evidence indicates that plants recognize insect oviposition and elicit direct or indirect defenses to reduce the pressure of future herbivory. Most of the oviposition-triggered plant defenses described thus far remove eggs or keep them away from the host plant or their desirable feeding sites. Here, we report induction of antiherbivore defense by insect oviposition which targets newly hatched larvae, not the eggs, in the system of tomato Solanum lycopersicum L., and tomato fruitworm moth Helicoverpa zea Boddie. When tomato plants were oviposited by H. zea moths, pin2, a highly inducible gene encoding protease inhibitor2, which is a representative defense protein against herbivorous arthropods, was expressed at significantly higher level at the oviposition site than surrounding tissues, and expression decreased with distance away from the site of oviposition. Moreover, more eggs resulted in higher pin2 expression in leaves, and both fertilized and unfertilized eggs induced pin2 expression. Notably, when quantified daily following deposition of eggs, pin2 expression at the oviposition site was highest just before the emergence of larvae. Furthermore, H. zea oviposition primed the wound-induced increase of pin2 transcription and a burst of jasmonic acid (JA); tomato plants previously exposed to H. zea oviposition showed significantly stronger induction of pin2 and higher production of JA upon subsequent simulated herbivory than without oviposition. Our results suggest that tomato plants recognize H. zea oviposition as a signal of impending future herbivory and induce defenses to prepare for this herbivory by newly hatched neonate larvae

Salivary Glucose Oxidase from Caterpillars Mediates the Induction of Rapid and Delayed-Induced Defenses in the Tomato Plant

Caterpillars produce oral secretions that may serve as cues to elicit plant defenses, but in other cases these secretions have been shown to suppress plant defenses. Ongoing work in our laboratory has focused on the salivary secretions of the tomato fruitworm, Helicoverpa zea. In previous studies we have shown that saliva and its principal component glucose oxidase acts as an effector by suppressing defenses in tobacco. In this current study, we report that saliva elicits a burst of jasmonic acid (JA) and the induction of late responding defense genes such as proteinase inhibitor 2 (Pin2). Transcripts encoding early response genes associated with the JA pathway were not affected by saliva. We also observed a delayed response to saliva with increased densities of Type VI glandular trichomes in newly emerged leaves. Proteomic analysis of saliva revealed glucose oxidase (GOX) was the most abundant protein identified and we confirmed that it plays a primary role in the induction of defenses in tomato. These results suggest that the recognition of GOX in tomato may represent a case for effector-triggered immunity. Examination of saliva from other caterpillar species indicates that saliva from the noctuids Spodoptera exigua and Heliothis virescens also induced Pin2 transcripts

MiDAS 4: A global catalogue of full-length 16S rRNA gene sequences and taxonomy for studies of bacterial communities in wastewater treatment plants

Microbial communities are responsible for biological wastewater treatment, but our knowledge of their diversity and function is still poor. Here, we sequence more than 5 million high-quality, full-length 16S rRNA gene sequences from 740 wastewater treatment plants (WWTPs) across the world and use the sequences to construct the ‘MiDAS 4’ database. MiDAS 4 is an amplicon sequence variant resolved, full-length 16S rRNA gene reference database with a comprehensive taxonomy from domain to species level for all sequences. We use an independent dataset (269 WWTPs) to show that MiDAS 4, compared to commonly used universal reference databases, provides a better coverage for WWTP bacteria and an improved rate of genus and species level classification. Taking advantage of MiDAS 4, we carry out an amplicon-based, global-scale microbial community profiling of activated sludge plants using two common sets of primers targeting regions of the 16S rRNA gene, revealing how environmental conditions and biogeography shape the activated sludge microbiota. We also identify core and conditionally rare or abundant taxa, encompassing 966 genera and 1530 species that represent approximately 80% and 50% of the accumulated read abundance, respectively. Finally, we show that for well-studied functional guilds, such as nitrifiers or polyphosphate-accumulating organisms, the same genera are prevalent worldwide, with only a few abundant species in each genus

Emission of Volatile Organic Compounds After Herbivory from Trifolium pratense (L.) Under Laboratory and Field Conditions

Plants emit a wide range of volatile organic compounds in response to damage by herbivores, and many of the compounds have been shown to attract the natural enemies of insect herbivores or serve for inter- and intra-plant communication. Most studies have focused on volatile emission in the laboratory while little is known about emission patterns in the field. We studied the emission of volatiles by Trifolium pratense (red clover) under both laboratory and field conditions. The emission of 24 compounds was quantified in the laboratory, of which eight showed increased emission rates after herbivory by Spodoptera littoralis caterpillars, including (E)-β-ocimene, the most abundant compound, (Z)-β-ocimene, linalool, (E)-β-caryophyllene, (E,E)-α-farnesene, 4,8-dimethyl-1,3,7-nonatriene (DMNT), 1-octen-3-ol, and methyl salicylate (MeSA). While most of these compounds have been reported as herbivore-induced volatiles from a wide range of plant taxa, 1-octen-3-ol seems to be a characteristic volatile of legumes. In the field, T. pratense plants with varying herbivore damage growing in established grassland communities emitted only 13 detectable compounds, and the correlation between herbivore damage and volatile release was more variable than in the laboratory. For example, the emission of (E)-β-ocimene, (Z)-β-ocimene, and DMNT actually declined with damage, while decanal exhibited increased emission with increasing herbivory. Elevated light and temperature increased the emission of many compounds, but the differences in light and temperature conditions between the laboratory and the field could not account for the differences in emission profiles. Our results indicate that the release of volatiles from T. pratense plants in the field is likely to be influenced by additional biotic and abiotic factors not measured in this study. The elucidation of these factors may be important in understanding the physiological and ecological functions of volatiles in plants

Signals in the Soil: An Introduction to Wireless Underground Communications

In this chapter, wireless underground (UG) communications are introduced. A detailed overview of WUC is given. A comprehensive review of research challenges in WUC is presented. The evolution of underground wireless is also discussed. Moreover, different component of UG communications is wireless. The WUC system architecture is explained with a detailed discussion of the anatomy of an underground mote. The examples of UG wireless communication systems are explored. Furthermore, the differences of UG wireless and over-the-air wireless are debated. Different types of wireless underground channel (e.g., In-Soil, Soil-to-Air, and Air-to-Soil) are reported as well

Unexpected high diversity of galling insects in the Amazonian upper canopy: The savanna out there

A relatively large number of studies reassert the strong relationship between galling insect diversity and extreme hydric and thermal status in some habitats, and an overall pattern of a greater number of galling species in the understory of scleromorphic vegetation. We compared galling insect diversity in the forest canopy and its relationship with tree richness among upland terra firme, várzea, and igapó floodplains in Amazonia, Brazil. The soils of these forest types have highly different hydric and nutritional status. Overall, we examined the upper layer of 1,091 tree crowns. Galling species richness and abundance were higher in terra firme forests compared to várzea and igapó forests. GLM-ANCOVA models revealed that the number of tree species sampled in each forest type was determinant in the gall-forming insect diversity. The ratio between galling insect richness and number of tree species sampled (GIR/TSS ratio) was higher in the terra firme forest and in seasonally flooded igapó, while the várzea presented the lowest GIR/TSS ratio. In this study, we recorded unprecedented values of galling species diversity and abundance per sampling point. The GIR/TSS ratio from várzea was approximately 2.5 times higher than the highest value of this ratio ever reported in the literature. Based on this fact, we ascertained that várzea and igapó floodplain forests (with lower GIA and GIR), together with the speciose terra firme galling community emerge as the gall diversity apex landscape among all biogeographic regions already investigated. Contrary to expectation, our results also support the "harsh environment hypothesis", and unveil the Amazonian upper canopy as similar to vegetation habitats, hygrothermically stressed environments with temperature at lethal limits and high levels of leaf sclerophylly. © 2014 Julião et al

Prevention of multidrug resistance (MDR) in osteosarcoma by NSC23925

Background: The major limitation to the success of chemotherapy in osteosarcoma is the development of multidrug resistance (MDR). Preventing the emergence of MDR during chemotherapy treatment has been a high priority of clinical and investigational oncology, but it remains an elusive goal. The NSC23925 has recently been identified as a novel and potent MDR reversal agent. However, whether NSC23925 can prevent the development of MDR in cancer is unknown. Therefore, this study aims to evaluate the effects of NSC23925 on prevention of the development of MDR in osteosarcoma. Methods: Human osteosarcoma cell lines U-2OS and Saos were exposed to increasing concentrations of paclitaxel alone or in combination with NSC23925 for 6 months. Cell sublines selected at different time points were evaluated for their drug sensitivity, drug transporter P-glycoprotein (Pgp) expression and activity. Results: We observed that tumour cells selected with increasing concentrations of paclitaxel alone developed MDR with resistance to paclitaxel and other Pgp substrates, whereas cells cultured with paclitaxel–NSC23925 did not develop MDR and cells remained sensitive to chemotherapeutic agents. Paclitaxel-resistant cells showed high expression and activity of the Pgp, whereas paclitaxel–NSC23925-treated cells did not express Pgp. No changes in IC50 and Pgp expression and activity were observed in cells grown with the NSC23925 alone. Conclusions: Our findings suggest that NSC23925 may prevent the development of MDR by specifically preventing the overexpression of Pgp. Given the significant incidence of MDR in osteosarcoma and the lack of effective agents for prevention of MDR, NSC23925 and derivatives hold the potential to improve the outcome of cancer patients with poor prognosis due to drug resistance