Higher order theory of quasi-isodynamicity near the magnetic axis of stellarators

The condition of quasi-isodynamicity is derived to second order in the distance from the magnetic axis. We do so using a formulation of omnigenity that explicitly requires the balance between the radial particle drifts at opposite bounce points of a magnetic well. This is a physically intuitive alternative to the integrated condition involving distances between bounce points, used in previous works. We investigate the appearance of topological defects in the magnetic field strength (``puddles''). A hallmark of quasi-isodynamic fields, the curved contour of minimum field strength, is found to be inextricably linked to these defects. Our results pave the way to constructing solutions that satisfy omnigenity to a higher degree of precision, and also to simultaneously consider other physical properties, like shaping and stability

Dorsal-CA1 hippocampal neuronal ensembles encode nicotine-reward contextual associations

Natural and drug rewards increase the motivational valence of stimuli in the environment that, through Pavlovian learning mechanisms, become conditioned stimuli that directly motivate behavior in the absence of the original unconditioned stimulus. While the hippocampus has received extensive attention for its role in learning and memory processes, less is known regarding its role in drug-reward associations. We used in vivo Ca2+ imaging in freely moving mice during the formation of nicotine preference behavior to examine the role of the dorsal-CA1 region of the hippocampus in encoding contextual reward-seeking behavior. We show the development of specific neuronal ensembles whose activity encodes nicotine-reward contextual memories and that are necessary for the expression of place preference. Our findings increase our understanding of CA1 hippocampal function in general and as it relates to reward processing by identifying a critical role for CA1 neuronal ensembles in nicotine place preference

Stress-induced reinstatement of nicotine preference requires dynorphin/kappa opioid activity in the basolateral amygdala

UNLABELLED: The dynorphin (DYN)/kappa-opioid receptor (KOR) system plays a conserved role in stress-induced reinstatement of drug seeking for prototypical substances of abuse. Due to nicotine\u27s high propensity for stress-induced relapse, we hypothesized that stress would induce reinstatement of nicotine seeking-like behavior in a KOR-dependent manner. Using a conditioned place preference (CPP) reinstatement procedure in mice, we show that both foot-shock stress and the pharmacological stressor yohimbine (2 mg/kg, i.p.) induce reinstatement of nicotine CPP in a norbinaltorphimine (norBNI, a KOR antagonist)-sensitive manner, indicating that KOR activity is necessary for stress-induced nicotine CPP reinstatement. After reinstatement testing, we visualized robust c-fos expression in the basolateral amygdala (BLA), which was reduced in mice pretreated with norBNI. We then used several distinct but complementary approaches of locally disrupting BLA KOR activity to assess the role of KORs and KOR-coupled intracellular signaling cascades on reinstatement of nicotine CPP. norBNI injected locally into the BLA prevented yohimbine-induced nicotine CPP reinstatement without affecting CPP acquisition. Similarly, selective deletion of BLA KORs in KOR conditional knock-out mice prevented foot-shock-induced CPP reinstatement. Together, these findings strongly implicate BLA KORs in stress-induced nicotine seeking-like behavior. In addition, we found that chemogenetic activation of Gαi signaling within CaMKIIα BLA neurons was sufficient to induce nicotine CPP reinstatement, identifying an anatomically specific intracellular mechanism by which stress leads to reinstatement. Considered together, our findings suggest that activation of the DYN/KOR system and Gαi signaling within the BLA is both necessary and sufficient to produce reinstatement of nicotine preference. SIGNIFICANCE STATEMENT: Considering the major impact of nicotine use on human health, understanding the mechanisms by which stress triggers reinstatement of drug-seeking behaviors is particularly pertinent to nicotine. The dynorphin (DYN)/kappa-opioid receptor (KOR) system has been implicated in stress-induced reinstatement of drug seeking for other commonly abused drugs. However, the specific role, brain region, and mechanisms that this system plays in reinstatement of nicotine seeking has not been characterized. Here, we report region-specific engagement of the DYN/KOR system and subsequent activation of inhibitory (Gi-linked) intracellular signaling pathways within the basolateral amygdala during stress-induced reinstatement of nicotine preference. We show that the DYN/KOR system is necessary to produce this behavioral state. This work may provide novel insight for the development of therapeutic approaches to prevent stress-related nicotine relapse

MR432: The Business Climate for Biotechnology in Maine

This report presents the findings from a survey of biotechnology firms located in Maine. The purpose of the survey, conducted during the spring of 2003, was to collect information on a variety of issues related to the companies. operations and the state.s business climate for biotechnology. Some of the issues addressed in the survey include the research and development activities of Maine biotechnology companies, partnerships formed within the biotechnology industry, and the companies’ participation in government-sponsored business assistance programs. The survey results present a “snapshot” of the industry in 2002, which can be used to establish a baseline against which to gauge future growth and changes to the industry in Maine.https://digitalcommons.library.umaine.edu/aes_miscreports/1021/thumbnail.jp

Homoclinic Orbits around Spinning Black Holes I: Exact Solution for the Kerr Separatrix

Under the dissipative effects of gravitational radiation, black hole binaries will transition from an inspiral to a plunge. The separatrix between bound and plunging orbits features prominently in the transition. For equatorial Kerr orbits, we show that the separatrix is a homoclinic orbit in one-to-one correspondence with an energetically-bound, unstable circular orbit. After providing a definition of homoclinic orbits, we exploit their correspondence with circular orbits and derive exact solutions for them. This paper focuses on homoclinic behavior in physical space, while in a companion paper we paint the complementary phase space portrait. The exact results for the Kerr separatrix could be useful for analytic or numerical studies of the transition from inspiral to plunge.Comment: 21 pages, some figure

Higgs Sector in Extensions of the MSSM

Extensions of the Minimal Supersymmetric Standard Model (MSSM) with additional singlet scalar fields solve the important mu-parameter fine tuning problem of the MSSM. We compute and compare the neutral Higgs boson mass spectra, including one-loop corrections, of the following MSSM extensions: Next-to-Minimal Supersymmetric Standard Model (NMSSM), the nearly-Minimal Supersymmetric Standard Model (nMSSM), and the U(1)'-extended Minimal Supersymmetric Standard Model (UMSSM) by performing scans over model parameters. We find that the Secluded U(1)'-extended Minimal Supersymmetric Standard Model (sMSSM) is identical to the nMSSM if three of the additional scalars decouple. The dominant part of the one-loop corrections are model-independent since the singlet field does not couple to MSSM particles other than the Higgs doublets. Thus, model-dependent parameters enter the masses only at tree-level. We apply constraints from LEP bounds on the Standard Model and MSSM Higgs boson masses and the MSSM chargino mass, the invisible Z decay width, and the Z-Z' mixing angle. Some extended models permit a Higgs boson with mass substantially below the SM LEP limit or above theoretical limits in the MSSM. Ways to differentiate the models via masses, couplings, decays and production of the Higgs bosons are discussed.Comment: 65 pages, 15 figures. Figure replaced and typos corrected. Version to appear in Phys. Rev.

Proceedings of the 21st Annual Meeting, Southern Soybean Disease Workers (March 6-8, 1994, Tulsa, Oklahoma)

Contents 1993-94 SSDW Committee Chairs 1993-94 SSDW Officers Graduate student competition Resistance of Soybean Cultivars in Maturity Group IV-VIII to Rotylenchulus reniformis. JJ Cornelius and GW Lawrence Evaluation of Susceptibility of Soybean to Red Crown Rot caused by Calonectria crotalariae in the Field. KD Kim, JS Russin, and JP Snow Contributed papers Soybean Disease Loss Estimate for the Southern United States During 1993, Table 1. Estimated percent Joss of soybean yields in 1993 to disease, Table 2. Estimated reduction of soybean yields in 1993 to disease, and Table 3. Southern states soybean disease loss estimate total in bushels and dollars, 1993. Compiled by JA Wrather Aerial Blight Associated with Delayed Maturity of Soybean. IA Fox, MA Blaine, and GL Sciumbato Relationship of Phytophthora Resistance to Soybean Yield. GL Sciumbato., FG Hancock, JA Fox, and D Boykin Effects of Long-Term Tillage Practices on Soil Populations of Microsclerotia of Macrophomina phaseolina. SR Kendig and JA Wrather Effect of Maturity Group, Growth Stage, and Planting Date on Progress of Sudden Death Syndrome of Soybean. JC Rupe and EE Gebur, Jr Additional Soybean Plant Introductions Resistant to Soybean Cyst Nematode. LD Young Frogeye Leaf Spot Control in Soybeans with Foliar-Fungicides. AY Chambers Interaction of the Root-Knot Nematode, Meloidogyne incognita, with Selected Weed Species Present in Soybean Fields in Louisiana. EC McGawley, JS Russin, and JL Griffin Population Development by Meloidogyne incognita and Heterodera glycines on Soybean Stressed by Weeds and Defoliation. JS Russin, EC McGawley, and LL Griffin Resistance to Rotylenchulus reniformis in Soybean. RT Robbins and L Rakes Treasurer\u27s report. GG Hammes Proceedings of the Southern Soybean Disease Workers are published annually by the Southern Soybean Disease Workers. Text, references, figures, and tables are reproduced as they were submitted by the authors. The opinions exposed by the participants at this conference are their own and do not necessarily represent the views of the Southern Soybean Disease Workers. Mention of trademark or propriety products in this Proceedings does not constitute a guarantee, warranty, or endorsement of that product by the Southern Soybean Disease Workers

Proceedings of the 22nd Annual Meeting, Southern Soybean Disease Workers (February 20-22, 1995, St. Louis, Missouri)

Contents Business session Soybean Disease Loss Estimate for the Southern United States during 1994. JA Wrather Treasurer report. GG Hammes SSDW Committee Chairmen for 1994-1995 Graduate student papers Host preference of Rotylenchulus reniformis for weed species common to Louisiana soybean. CH Carter, EC McGawley, and JS Russin Development of an immunoassay for Heterodera glycines eggs. MJ Kennedy, JE Schoelz, TL Niblack, PA Donald Effects of delayed planting and host susceptibility on colonization of soybean by Calonectria crotalariae and development of red crown rot. PU Kuruppu, JS Russin, and EC McGawley Effects of long-term corn/soybean rotation on pathogenicity of Pythium populations on soybean. BQ Zhang and XB Yang Contributed papers Possible shift to more virulent Phytophthora races in Mississippi. GL Sciumbato and BL Keeling The relationship between trehalose content and dormancy of soybean cyst nematode, Heterodera glycines. JH Yen, AL Karr, TL Niblack, and WJ Weibold Fertilization effects on Sudden Death Syndrome (SDS) in soybeans. MA Newman, AY Chambers, and DD Howard Screening southern soybean cultivars for reaction to aerial blight. BG Harville, JS Russin, and RJ Habetz Comparison of continuous soybean, fallow, and rotation with sorghum-sudan grass hybrid for nematode control in a field infested with root-knot and soybean cyst nematodes. R Rodríguez-Kábana, DB Weaver, and EL Carden Recent progress in identifying soybean cultivars field tolerance of Macrophomina phaseolina. GS Smith and ON Carvil Major soybean diseases in Brazil. JT Yorinori Pre- and post-infection efficacy of benomyl for the control of stem canker of soybean. JC Rupe and CM Becton Comparison of continuous soybean and rotation with cotton for nematode control in a field infested with root-knot and soybean cyst nematodes. DB Weaver, R Rodríguez-Kábana, and EL Carden A rapid screening method for resistance to nematodes and soilborne pathogens using alginate films. N Kokalis-Burelle, N Martínez-Ochoa, DB Weaver, and R Rodríguez-Kábana Progress of a project to identify differential cultivars and races of Cercospora sojina. DV Phillips and HR Boerma Proceedings of the Southern Soybean Disease Workers are published annually by the Southern Soybean Disease Workers. Text, references, figures, and cables are reproduced as they were submitted by the authors. The opinions exposed by the participants at this conference are their own and do not necessarily represent the views of the Southern Soybean Disease Workers. Mention of trademark, or propriety products in this Proceedings does not constitute a guarantee, warranty, or endorsement of that produce by the Southern Soybean Disease Workers