34,094 research outputs found

    Electroantennogram Responses of the Armyworm (Lepidoptera: Noctuidae) and Cereal Leaf Beetle (Coleoptera: Chrysomelidae) to Volatile Chemicals of Seedling Oats

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    Armyworm, Pseudaletia unipuncta, eIectroantennogram (EAG) responses to 10 volatile chemicals of seedling oats and three of injured green plants were significantly different from each other while cereal leaf beetle, Oulema melallopus, EAG responses were not significantly different. The EAG responses of both species did not vary significantly with respect to sex, age, or between the antennae of the same specimen. (E)-2-hexenol, a compound extracted from injured green plants, yielded the highest peak response for the armyworm while more cereal leaf beetle antennae responded to this chemical than any other chemical. Armyworm antennallife averaged 38 + 20 min while those of the cereal leaf beetle averaged 6 + 14 min

    The role of Eag and HERG channels in cell proliferation and apoptotic cell death in SK-OV-3 ovarian cancer cell line.

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    The voltage gated potassium (K+) channels Eag and HERG have been implicated in the pathogenesis of various cancers, through association with cell cycle changes and programmed cell death. The role of these channels in the onset and progression of ovarian cancer is unknown. An understanding of mechanism by which Eag and HERG channels affect cell proliferation in ovarian cancer cells is required and therefore we investigated their role in cell proliferation and their effect on the cell cycle and apoptosis of ovarian cancer cells

    Biochemical Effects of Exercise on a Fasciocutaneous Flap in a Rat Model.

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    Importance: An overwhelming amount of data suggest that cardiovascular exercise has a positive effect on the mind and body, although the precise mechanism is not always clear. Objective: To assess the clinical and biochemical effects of voluntary cardiovascular exercise on pedicled flaps in a rodent model. Design, Setting, and Participants: Eighteen adult Sprague-Dawley male rats were randomized into a resting animal group (RAG) (n=9) and an exercise animal group (EAG) (n=9) for 14 days (July 23, 2013, through July 30, 2013). A pedicled transposition flap was performed on the ventral surface of the rat, and biopsy specimens were taken from the proximal, middle, and distal portions on postoperative days 0, 2, 5, and 9. Flap survival was analyzed planimetrically, and biopsy specimens were analyzed by hematoxylin-eosin-stained microscopy and immunoblotting. The housing, exercise, surgery, and analysis of the rats were conducted at a single basic science research laboratory at the tertiary care center campus of Thomas Jefferson University in Philadelphia, Pennsylvania. Exposures: The rats were caged for 14 days or housed in a cage connected to an exercise wheel and pedometer. Main Outcomes and Measures: Study measures were gross and micrographic necrosis and expression of proteins within cell survival and apoptosis pathways. Results: A total of 18 rats were studied, 9 in the RAG and 9 in the EAG. the mean (SEM) amount of necrosis in flaps was 41.3% (3%) in the RAG rats and 10.5% (3.5%) in the EAG rats (P \u3c .001). Immunoblotting revealed increased Caspase-9 activity resulting in poly-(adenosine diphosphate-ribose) polymerase 1 cleavage in the RAG vs the EAG, as well as lower phosphorylated protein kinase B (also known as Akt), signal transducer and activator of transcription 3, and total B-cell leukemia/lymphoma 2 protein levels. Throughout the postoperative period, the cumulative vascular endothelial growth factor A levels of the EAG flaps were significantly higher than those of the RAG flaps (2.30 vs 1.25 fold induction [FI], P = .002), with differences of 2.76 vs 1.54 FI in the proximal segment, 2.40 vs 1.20 FI in the middle segment, and 1.90 vs 0.79 FI in the distal segment. A similar response was noted when comparing phosphorylated Akt, with cumulative mean (SEM) p-Akt expression levels of 0.62 (0.04) for RAG and 1.98 (0.09) for EAG (P = .002 between the 2 groups). Conclusions and Relevance: Voluntary preoperative exercise improves survival in pedicled fasciocutaneous flaps; the EAG rats had less necrosis, decreased apoptotic markers, and increased amounts of vascular endothelial growth factor A and prosurvival proteins. These results have implications to increase flap survival in other mammal populations, such as humans. Level of Evidence: 3

    Modulation of different K+ currents in Drosophila: a hypothetical role for the Eag subunit in multimeric K+ channels

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    We examined the role of the ether a go-go (eag) gene in modulation of K+ currents and the possibility of its protein product Eag as a subunit in the heteromultimeric assembly of K+ channels by voltage-clamp analysis of larval muscle membrane currents. Previous DNA sequence studies indicate that the eag gene codes for a polypeptide homologous to, but distinct from, the Shaker (Sh) K+ channel subunits (Warmke et al., 1991), and electrophysiological recordings revealed allele-specific effects of eag on four identified K+ currents in Drosophila larval muscles (Zhong and Wu, 1991). Further studies of eag alleles indicated that none of the eag mutations, including alleles producing truncated mRNA messages, eliminate any of the four K+ currents, and that the mutational effects exhibit strong temperature dependence. We found that both W7, an antagonist of Ca2+/calmodulin, and cGMP analogs modulated K+ currents and that their actions were altered or even abolished by eag mutations. These results suggest a role of eag in modulation of K+ currents that may subserve integration of signals at a converging site of the two independent modulatory pathways. The Sh locus is known to encode certain subunits of the IA channel in larval muscle. The existence of multiple eag and Sh alleles enabled an independent test of the idea of Eag as a K+ channel subunit by studying IA in different double-mutant combinations. An array of allele-specific interaction between eag and Sh was observed, which reflects a close association between the Sh and eag subunits within the IA channel. Taken together, our data strengthen the possibility that the eag locus provides a subunit common to different K+ channels. The role of the eag subunit for modulating channels, as opposed to that of Sh subunits required for gating, selectivity, and conductance of the channel, suggest a combinatorial genetic framework for generating diversified K+ channels

    Potassium channels as tumour markers

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    AbstractAn increasing number of ion channels are being found to be causally involved in diseases, giving rise to the new field of “channelopathies”. Cancer is no exception, and several ion channels have been linked to tumour progression. Among them is the potassium channel EAG (Ether-a-go-go). Over 75% of tumours have been tested positive using a monoclonal antibody specific for EAG, while inhibition of this channel decreased the proliferation of EAG expressing cells. The inhibition of EAG is accomplished using RNA interference, functional anti-EAG1 antibodies, or (unspecific) EAG channel blockers. Fluorescently labelled recombinant Fab fragments recognizing EAG allow the distribution of EAG to be visualized in an in vivo mouse tumour model

    Signaling, Learning and Screening Prior to Trial: Informational Implications of Preliminary Injunctions

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    The decision to request a preliminary injunction—a court order that bans a party from certain actions until their lawfulness are ascertained in a final court ruling at trial—is an important litigation instrument in many areas of the law including antitrust, copyright, patents, trademarks, employment and labor relations as well as contracts. The process of filing for a preliminary injunction and the court's ruling on such a request generates information that can affect possible settlement decisions. We consider these implications when there is uncertainty about both the plaintiff's damages as well as the merits of case in the eyes of the court. Both plaintiff and defendant revise their beliefs about the case strength in dispute once they observe the court's ruling on preliminary injunctive relief. We study how such learning affects the likelihood of settlement. A precursor to this analysis is the study of the strategic role of preliminary injunctions as a means to signal the plaintiff's willingness to settle.preliminary injunction, learning, signaling, screening, litigation, pre-trial motion, settlement

    Dynamic Contract Breach

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    This paper studies the design of optimal, privately-stipulated damages when breach of contract is possible at more than one point in time. It offers an intuitive explanation for why cancellation fees for some services (e.g., hotel reservations) increase as the time for performance approaches. If the seller makes investments over time to improve her value from trade, she will protect the value of her investments by demanding a higher compensation when the buyer breaches their contract at a time closer to when contract performance is due. Furthermore, it is shown that if the seller may be able to find an alternate buyer when breach occurs early but not when breach occurs late, the amount by which the damage for late breach exceeds the damage for early breach is increasing in the probability of finding an alternate buyer. (This result may explain why some hotels impose larger penalties for last-minute cancellations during the high season than during the low season.) When the probability of finding an alternate buyer is endogenized, the seller's private incentive to mitigate breach damages is shown to be socially insufficient whenever she does not have complete bargaining power with the alternate buyer. Finally, if renegotiation is possible after the arrival of each perfectly competitive entrant, the efficient breach and investment decisions are shown to be implementable with the same efficient expectation damages that implement the efficient outcomes absent renegotiation.Contract, Breach

    Against the Stand-Alone-Cost Test in U.S. Freight Rail Regulation

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    The stand-alone-cost test has become an expensive, extensive, and time-consuming part of the regulatory practice of the U.S. Surface Transportation Board in the performance of its statutory duty to protect "captive shippers" from monopoly rail rates. Worse, a close examination of the history of its adoption and application suggests only a very tenuous connection with its claimed intellectual foundations, the classic works of Faulhaber (1975) and Baumol, Panzar, and Willig (1982). It is time to retire this tool and replace it with something simpler and more effective and transparent.
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