Chronic Loss of Melanin-Concentrating Hormone Affects Motivational Aspects of Feeding in the Rat

Current epidemic obesity levels apply great medical and financial pressure to the strenuous economy of obesity-prone cultures, and neuropeptides involved in body weight regulation are regarded as attractive targets for a possible treatment of obesity in humans. The lateral hypothalamus and the nucleus accumbens shell (AcbSh) form a hypothalamic-limbic neuropeptide feeding circuit mediated by Melanin-Concentrating Hormone (MCH). MCH promotes feeding behavior via MCH receptor-1 (MCH1R) in the AcbSh, although this relationship has not been fully characterized. Given the AcbSh mediates reinforcing properties of food, we hypothesized that MCH modulates motivational aspects of feeding

Characterization of eight polymorphic microsatellite loci for the California spiny lobster, Panulirus interruptus and cross-amplification in other achelate lobsters

Microsatellite sequences were isolated from both non-enriched and enriched genomic libraries of California spiny lobster, Panulirus interruptus. Eight consistently amplifying, scorable and polymorphic loci were characterized for 79 individuals collected at Santa Cruz and San Clemente Islands, California, and tested for cross-species amplification in four closely related Panulirus spp., as well as four other species of the order Achelata. The number of alleles observed per locus ranged from three to 54 and observed heterozygosities ranged from 0.57 to 0.98. Quality control testing shows that all loci were reliably scorable, independently segregating, inherited in Mendelian ratios, and had low to moderate (≤14.4%) frequencies of null alleles and high statistical power for detecting fine scale genetic structure

Characterization of eight polymorphic microsatellite loci for the California spiny lobster, Panulirus interruptus and cross-amplification in other achelate lobsters

Microsatellite sequences were isolated from both non-enriched and enriched genomic libraries of California spiny lobster, Panulirus interruptus. Eight consistently amplifying, scorable and polymorphic loci were characterized for 79 individuals collected at Santa Cruz and San Clemente Islands, California, and tested for cross-species amplification in four closely related Panulirus spp., as well as four other species of the order Achelata. The number of alleles observed per locus ranged from three to 54 and observed heterozygosities ranged from 0.57 to 0.98. Quality control testing shows that all loci were reliably scorable, independently segregating, inherited in Mendelian ratios, and had low to moderate (≤14.4%) frequencies of null alleles and high statistical power for detecting fine scale genetic structure

Diversity and Structure of Parrotfish Assemblages across the Northern Great Barrier Reef

The structure and dynamics of coral reef environments vary across a range of spatial scales, with patterns of associated faunal assemblages often reflecting this variability. However, delineating drivers of biological variability in such complex environments has proved challenging. Here, we investigated the assemblage structure and diversity of parrotfishes—a common and ecologically important group—across 6° of latitude on the Northern Great Barrier Reef (GBR), Australia. Parrotfish abundance and biomass were determined from stereo-video surveys across 82 sites spanning 31 reefs and assessed against geographic, biophysical, and management-related factors in a multivariate framework to determine major drivers and associated scales of assemblage structure. Large cross-shelf variation in parrotfish assemblages pervaded along the entire Northern GBR, with distinct assemblages associated with sheltered and exposed reefs. Species abundances and diversity generally decreased with decreasing latitude. The gradient of explicit predator biomass associated with management zoning had no effect on parrotfish assemblage structure, but was positively correlated with parrotfish diversity. Our results highlight the ubiquitous presence of cross-shelf variation, where the greatest differences in parrotfish community composition existed between sheltered (inner and mid shelf) and exposed (outer shelf) reef systems. Prior attempts to explain linkages between parrotfishes and fine-scale biophysical factors have demonstrated parrotfishes as habitat generalists, but recent developments in nutritional ecology suggest that their cross-shelf variation on the GBR is likely reflective of benthic resource distribution and species-specific feeding modes

The diverse lives of progenitors of hydrogen-rich core-collapse supernovae: the role of binary interaction

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The diverse lives of progenitors of hydrogen-rich core-collapse supernovae: the role of binary interaction

Hydrogen-rich supernovae, known as Type II (SNe II), are the most common class of explosions observed following the collapse of the core of massive stars. We used analytical estimates and population synthesis simulations to assess the fraction of SNe II progenitors that are expected to have exchanged mass with a companion prior to explosion. We estimate that 1/3 to 1/2 of SN II progenitors have a history of mass exchange with a binary companion before exploding. The dominant binary channels leading to SN II progenitors involve the merger of binary stars. Mergers are expected to produce a diversity of SN II progenitor characteristics, depending on the evolutionary timing and properties of the merger. Alternatively, SN II progenitors from interacting binaries may have accreted mass from their companion, and subsequently been ejected from the binary system after their companion exploded. We show that the overall fraction of SN II progenitors that are predicted to have experienced binary interaction is robust against the main physical uncertainties in our models. However, the relative importance of different binary evolutionary channels is affected by changing physical assumptions. We further discuss ways in which binarity might contribute to the observed diversity of SNe II by considering potential observational signatures arising from each binary channel. For supernovae which have a substantial H-rich envelope at explosion (i.e., excluding Type IIb SNe), a surviving non-compact companion would typically indicate that the supernova progenitor star was in a wide, non-interacting binary. We argue that a significant fraction of even Type II-P SNe are expected to have gained mass from a companion prior to explosion.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]