Differences in Thermal Tolerance Between Two Thermally Isolated and Genetically Indistinct Populations of \u3ci\u3eParagnetina Media\u3c/i\u3e (Walker) (Plecoptera: Perlodidae)

The critical thermal maximum (CTM) of Paragnetina media (Walker) (Plecoptera: Perlodidae) was studied at two sites of the Big Sable River in northwestern Lower Michigan during summer 2013. The sites were separated by ~8 km and differed in temperature by ~1°C in the early spring to ~5°C in mid-summer. Individual P. media specimens from the warm site had consistently higher CTM when acclimated to the mean temperature of the two sites for 3 days prior to experimental trials during May, June, and July. When acclimated for an additional 3 days to a higher or lower temperature, this thermal disadvantage disappeared. Groups of individuals from both sites simultaneously acclimated to both site temperatures for 3 days exhibited similar CTMs, except that cold site specimens acclimated to the cold temperature had a lower CTM than the other treatments. Sequencing of the CO1 gene revealed that nearly 75% of specimens shared a single haplotype, which was found in both warm and cold site individuals. Our results suggest that both long term and short term thermal history can influence thermal tolerance within populations of the same species that do not appear genetically distinct

Differences in Thermal Tolerance Between Two Thermally Isolated and Genetically Indistinct Populations of \u3ci\u3eParagnetina Media\u3c/i\u3e (Walker) (Plecoptera: Perlodidae)

The critical thermal maximum (CTM) of Paragnetina media (Walker) (Plecoptera: Perlodidae) was studied at two sites of the Big Sable River in northwestern Lower Michigan during summer 2013. The sites were separated by ~8 km and differed in temperature by ~1°C in the early spring to ~5°C in mid-summer. Individual P. media specimens from the warm site had consistently higher CTM when acclimated to the mean temperature of the two sites for 3 days prior to experimental trials during May, June, and July. When acclimated for an additional 3 days to a higher or lower temperature, this thermal disadvantage disappeared. Groups of individuals from both sites simultaneously acclimated to both site temperatures for 3 days exhibited similar CTMs, except that cold site specimens acclimated to the cold temperature had a lower CTM than the other treatments. Sequencing of the CO1 gene revealed that nearly 75% of specimens shared a single haplotype, which was found in both warm and cold site individuals. Our results suggest that both long term and short term thermal history can influence thermal tolerance within populations of the same species that do not appear genetically distinct

Dynamic scaling for 2D superconductors, Josephson junction arrays and superfluids

The value of the dynamic critical exponent $z$ is studied for two-dimensional superconducting, superfluid, and Josephson Junction array systems in zero magnetic field via the Fisher-Fisher-Huse dynamic scaling. We find $z\simeq5.6\pm0.3$, a relatively large value indicative of non-diffusive dynamics. Universality of the scaling function is tested and confirmed for the thinnest samples. We discuss the validity of the dynamic scaling analysis as well as the previous studies of the Kosterlitz-Thouless-Berezinskii transition in these systems, the results of which seem to be consistent with simple diffusion ($z=2$). Further studies are discussed and encouraged.Comment: 19 pages in two-column RevTex, 8 embedded EPS figure

Custom Integrated Circuits

Contains table of contents for Part III, table of contents for Section 1 and reports on eleven research projects.IBM CorporationMIT School of EngineeringNational Science Foundation Grant MIP 94-23221Defense Advanced Research Projects Agency/U.S. Army Intelligence Center Contract DABT63-94-C-0053Mitsubishi CorporationNational Science Foundation Young Investigator Award Fellowship MIP 92-58376Joint Industry Program on Offshore Structure AnalysisAnalog DevicesDefense Advanced Research Projects AgencyCadence Design SystemsMAFET ConsortiumConsortium for Superconducting ElectronicsNational Defense Science and Engineering Graduate FellowshipDigital Equipment CorporationMIT Lincoln LaboratorySemiconductor Research CorporationMultiuniversity Research IntiativeNational Science Foundatio

Old Mice, Young Islands And Competing Biogeographical Hypotheses

Naturally occurring variation within a small rodent species native to the southeastern USA, Peromyscus polionotus, has interested biologists for nearly a century. This species has contributed significantly to our understanding of geographical variation and has often been presented as an example of adaptive evolution. Much of the interest in this organism has been predicated on assumptions that the species is relatively young (\u3c 300 000 bp) and that coastal populations have a very recent history (\u3c 10 000 bp). To test these assumptions and the prevailing biogeographical hypothesis (Recurrent Invasion), we examined nucleotide sequence data from the cytochrome b and D-loop mitochondrial regions (2449 bp) for 79 samples of P. polionotus collected across the Gulf Coast region of Florida and Alabama. Samples representing Peromyscus maniculatus bairdii, P. m. sonoriensis, P. m. pallescens, and P. keeni were used as outgroups. The degree of cytochrome b divergence (≈ 4.4%) between P. maniculatus and P. polionotus was higher than expected. Analyses consistently indicated that three distinct groups are represented within P. polionotus from the Gulf Coast region. Among these, coastal populations (beach mice) form a monophyletic group and apparently represent a substantially older group (≈ 200 000 year. separation) than previously recognized. Our results were counter to the core assumptions of the existing biogeographical model but were consistent with an alternative hypothesis (Shore-line Tracking) which provides a more parsimonious explanation for the observed patterns. This research provides new insight into the evolutionary history of P. polionotus and highlights the importance of considering biogeographical history when evaluating extant patterns of natural variation. © 2007 The Authors

Genetic Relatedness And Spatial Associations Of Jointly Captured Alabama Beach Mice (Peromyscus Polionotus Ammobates)

Genetic relatedness estimates and capture records were used to examine population ecology of endangered Alabama beach mice (Peromyscus polionotus ammobates). Because of their monogamous mating strategy, biparental natal care, and limited dispersal patterns, we hypothesized that beach mice form gamodemes with family groups representing the core units. Under this hypothesis, we predicted that groups of related individuals would utilize common habitat spaces and that nonrandom age or sex associations could occur. To test these predictions, livetrapping data from an 8-year study were used to examine demography and relatedness of mice involved in joint and single captures (4,683 capture events involving 1,404 individuals, of which 949 were genotyped using microsatellite data). Mice were observed in joint captures nonrandomly with respect to age and sex, implying that there are nonrandom spatial associations among beach mice. Specifically, adult females were captured more often than expected with adult males and subadults were involved in joint captures more often than expected. Subadults captured with adults were the most related cocaptures, which, along with parental assignment, provided evidence of familial clustering. Adult male-female cocaptures were among the least related pairings, suggesting that inbreeding avoidance may play a role in mate choice. © 2007 American Society of Mammalogists

Custom Integrated Circuits

Contains table of contents for Part III, table of contents for Section 1, and reports on twelve research projects.IBM CorporationMIT School of EngineeringNational Science Foundation Grant MIP 94-23221Defense Advanced Research Projects Agency/U.S. Army Intelligence Center Contract DABT63-94-C-0053Mitsubishi CorporationNational Science Foundation/Young Investigator Award Fellowship MIP 92-58376Defense Advanced Research Projects Agency/ U.S. Navy - Office of Naval Research Contract N00014-94-1-0985National Science Foundation Grant MIP 91-17724U.S. Navy - Office of Navel Research Contract N00174-93-K-0035Analog Devices CorporationFederal Bureau of Investigation Contract J-FBI-92-196Defense Advanced Research Projects Agency/Consortium for Superconducting Electronics Contract MDA 972-90-C-0021National Defense Science and Engineering Graduate FellowshipDefense Advanced Research Projects Agency Contract DABT63-94-C-0053Digital Equipment CorporationMIT Lincoln LaboratorySemiconductor Research Corporation Contract SRC 95-SJ-558U.S. Army Contract DABT63-95-C-0088Motorola Corporatio