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Full-Text Articles in Life Sciences
Sex Can Be Dangerous: Acoustically-Orienting Parasitoids On Field Crickets (Orthoptera: Gryllidae), Gita R. Kolluru
Sex Can Be Dangerous: Acoustically-Orienting Parasitoids On Field Crickets (Orthoptera: Gryllidae), Gita R. Kolluru
Biological Sciences
The Orthopterists' Society generously awarded me grants in 1995 and 1997 to conduct research on Teleogryllus oceanicus (Orthoptera: Gryllidae) on the Big Island of Hawaii. Here I report results to date from fieldwork conducted in the past few years.
Exploitations Of Sexual Signals By Predators And Parasitoids, Marlene Zuk, Gita R. Kolluru
Exploitations Of Sexual Signals By Predators And Parasitoids, Marlene Zuk, Gita R. Kolluru
Biological Sciences
Signals used to attract mates are often conspicuous to predators and parasites, and their evolution via sexual selection is expected to be opposed by viability selection. Many secondary sexual traits may represent a compromise between attractiveness and avoidance of detection. Although such signal exploitation appears to be widespread, most examples come from species that use acoustic or olfactory mating signals, and relatively few cases of visual signal exploitation can be substantiated. Because males are usually the signaling sex, they are more at risk from predators or parasitoids that locate prey or hosts by sexual signals; this differential selection on the …
Photosynthetic Parameters And Empirical Modeling Of Primary Production: A Case Study On The Antarctic Peninsula Shelf, Mark A. Moline, Oscar Schofield, Nicolas P. Boucher
Photosynthetic Parameters And Empirical Modeling Of Primary Production: A Case Study On The Antarctic Peninsula Shelf, Mark A. Moline, Oscar Schofield, Nicolas P. Boucher
Biological Sciences
Eight hundred photosynthesis-irradiance relationships were determined in the shelf waters adjacent to Palmer Station, Antarctica during the spring/summer periods of 1991–94. Biomass specific maximum photosynthetic rate, PBmax, and the light limited photosynthetic efficiency, αB, were poorly correlated to the physical forcing and nutrient regimes at the sampling stations. The two photosynthetic parameters, however, did strongly covary indicating the minimum irradiance required to saturate photosynthesis, Ik, was relatively constant in this highly variable environment. The variability in Ik could partially be attributed to both depth in the water column and time of the …
Rostral-Caudal Variation In Troponin T And Parvalbumin Correlates With Differences In Relaxation Rates Of Cod Axial Muscle, Tierney M. Thys, Jason M. Blank, Fred H. Schachat
Rostral-Caudal Variation In Troponin T And Parvalbumin Correlates With Differences In Relaxation Rates Of Cod Axial Muscle, Tierney M. Thys, Jason M. Blank, Fred H. Schachat
Biological Sciences
Relaxation rate is an important determinant of axial muscle power production during the oscillatory contractions of undulatory locomotion. Recently, significant differences have been reported in the relaxation rates of rostral versus caudal white muscle fibers of the Atlantic cod Gadus morhua L. The present study investigates the biochemical correlates of this rostral-caudal physiological variation. Using denaturing gel electrophoresis, a series of fresh muscle samples from the dorsal epaxial muscle region was analyzed and several differences were detected. First, a gradual shift occurs in the expression of two troponin T isoforms along the length of the body. Second, rostral muscles were …
Metamorphis Is Not A New Beginning, Jan A. Pechenik, Dean E. Wendt, Jeremiah N. Jarrett
Metamorphis Is Not A New Beginning, Jan A. Pechenik, Dean E. Wendt, Jeremiah N. Jarrett
Biological Sciences
No abstract provided.
Sequence Analysis Of Bacterial Dna In The Colon Of An Andean Mummy, Massimo Ubaldi, Stefania Luciani, Isolina Marota, Gino Fornaciari, Raul J. Cano, Franco Rollo
Sequence Analysis Of Bacterial Dna In The Colon Of An Andean Mummy, Massimo Ubaldi, Stefania Luciani, Isolina Marota, Gino Fornaciari, Raul J. Cano, Franco Rollo
Biological Sciences
We have isolated DNA from 14 tissue samples from the internal organs of an Andean human mummy (10th–11th century A.D.) and have checked the persistence of the original human and bacterial templates using the following main approaches: 1) amino acid racemization test; 2) quantification of mitochondrial DNA copy number; 3) survey of bacterial DNA in the different organs; 4) sequence analysis of bacterial amplicons of different lengths. The results demonstrate that both the original human DNA and the DNA of the bacteria of the mummy gut are preserved. In particular, sequence analysis of two (respectively 100 and 196 bp in …
Effect Of Larval Swimming Duration On Growth And Reproduction Of Bugula Neritina (Bryozoa) Under Field Conditions, Dean E. Wendt
Effect Of Larval Swimming Duration On Growth And Reproduction Of Bugula Neritina (Bryozoa) Under Field Conditions, Dean E. Wendt
Biological Sciences
A growing body of evidence indicates that even subtle events occurring during one portion of an animal's life cycle can have detrimental, and in some cases, lasting effects on later stages. Using a laboratory-field transplant design, postmetamorphic costs associated with the duration of larval swimming were investigated in the bryozoan Bugula neritina. Larvae were induced to metamorphose in the laboratory after swimming for either less than 1 h or between 23 and 24 h; colonies that developed from these two groups of larvae are referred to hereafter as "1-h colonies" and "24-h colonies," respectively. After completing metamorphosis, individuals were …
Rapid Detection Of Listeria Monocytogenes In Dairy Samples Utilizing A Pcr-Based Fluorogenic 5′ Nuclease Assay, T. Cox, C. Frazier, J. Tuttle, S. Flood, L. Yagi, C. T. Yamashiro, R. Behari, C. Paszko, R. J. Cano
Rapid Detection Of Listeria Monocytogenes In Dairy Samples Utilizing A Pcr-Based Fluorogenic 5′ Nuclease Assay, T. Cox, C. Frazier, J. Tuttle, S. Flood, L. Yagi, C. T. Yamashiro, R. Behari, C. Paszko, R. J. Cano
Biological Sciences
The presence of Listeria monocytogenes as a dairy food contaminant is a lethal threat to dairy industrialists; therefore, products tainted with L. monocytogenes must be quickly detected and removed from production. This fluorogenic PCR-based assay was developed to rapidly detect L. monocytogenes contamination in dairy samples before a final product is distributed. The detection method employed uses a PCR primer pair and a fluorogenic TaqMan probe which bind to a region of a virulence determinant gene specific to L. monocytogenes. As the DNA target is amplified, the 5′ nuclease activity of Taq DNA polymerase hydrolyzes the internal fluorogenic probe …
Is Population Genetics Mired In The Past?, Andrew J. Bohonak, Neil Davies, George K. Roderick, Francis X. Villablanca
Is Population Genetics Mired In The Past?, Andrew J. Bohonak, Neil Davies, George K. Roderick, Francis X. Villablanca
Biological Sciences
No abstract provided.
Identification Of A Functional Homolog Of The Yeast Copper Homeostasis Gene Atx1 From Arabidopsis, Edward Himelblau, Helena Mria, Su-Ju Lin, Valeria Cizewski Culotta, Lola Penarrubia, Richard M. Amasino
Identification Of A Functional Homolog Of The Yeast Copper Homeostasis Gene Atx1 From Arabidopsis, Edward Himelblau, Helena Mria, Su-Ju Lin, Valeria Cizewski Culotta, Lola Penarrubia, Richard M. Amasino
Biological Sciences
A cDNA clone encoding a homolog of the yeast (Saccharomyces cerevisiae) gene Anti-oxidant 1 (ATX1) has been identified from Arabidopsis. This gene, referred to as Copper CHaperone (CCH), encodes a protein that is 36% identical to the amino acid sequence of ATX1 and has a 48-amino acid extension at the C-terminal end, which is absent from ATX1 homologs identified in animals. ATX1-deficient yeast (atx1) displayed a loss of high-affinity iron uptake. Expression of CCH in the atx1 strain restored high-affinity iron uptake, demonstrating that CCH is a functional homolog of ATX1 …
Invasion Genetics Of The Mediterranean Fruit Fly: Variation In Multiple Nuclear Introns, F. X. Villablanca, G. K. Roderick, S. R. Palumbi
Invasion Genetics Of The Mediterranean Fruit Fly: Variation In Multiple Nuclear Introns, F. X. Villablanca, G. K. Roderick, S. R. Palumbi
Biological Sciences
Biological invasions generally start from low initial population sizes, leading to reduced genetic variation in nuclear and especially mitochondrial DNA. Consequently, genetic approaches for the study of invasion history and population structure are difficult. An extreme example is the Mediterranean fruit fly, Ceratitis capitata (Medfly), for which successive invasions during this century have resulted in a loss of 60% of ancestral genetic variation in isozymes and 75% of variation in mitochondrial DNA. Using Medflies as an example, we present a new approach to invasion genetics that measures DNA sequence variation within introns from multiple nuclear loci. These loci are so …
Staphylococcus Succi Nus Sp. Nov., Isolated From Dominican Amber, L. H. Lambert, T. Cox, K. Mitchell, R. A. Rosselló-Mora, C. Del Cueto, D. E. Dodge, P. Orkand, R. J. Cano
Staphylococcus Succi Nus Sp. Nov., Isolated From Dominican Amber, L. H. Lambert, T. Cox, K. Mitchell, R. A. Rosselló-Mora, C. Del Cueto, D. E. Dodge, P. Orkand, R. J. Cano
Biological Sciences
Two bacterial isolates, designated AMG-D1Tand AMG-D2, were recovered from 25-35-million-year-old Dominican amber. AMG-D1Tand AMG-D2 biochemically most closely resemble Staphylococcus xylosus; they differ physiologically from other staphylococci. Fatty acid analysis and comparisons with extensive databases were unable to show relatedness to any specific taxon. Moreover, AMG-D1Tand AMG-D2 contain tuberculostearic acid and meso-diaminopimelic acid, characteristic of the G+C-rich coryneform bacteria, as opposed to L-lysine characteristic of staphylococci. AMG-D1Tand AMG-D2 have a G+C ratio of 35 mol%. Phylogenetic analysis with the 16S rRNA gene indicated that AMG-D1Tand AMG-D2 were most closely …
Terminal Restriction Fragment Patterns (Trfps), A Rapid, Pcr-Based Method For The Comparison Of Complex Bacterial Communities, Brian G. Clement, Lucia E. Kehl, Kristin L. Debord, Christopher L. Kitts
Terminal Restriction Fragment Patterns (Trfps), A Rapid, Pcr-Based Method For The Comparison Of Complex Bacterial Communities, Brian G. Clement, Lucia E. Kehl, Kristin L. Debord, Christopher L. Kitts
Biological Sciences
Microbial populations in complex environmental samples are difficult to characterize; current techniques are incomplete and time consuming. We investigated a polymerase chain reaction (PCR)-based method for rapidly comparing bacterial communities independent of culture or cloning. Community 16S rRNA genes were amplified and fluorescently labeled by PCR. The labeled products were digested by a restriction enzyme and the labeled, terminal restriction fragments (TRFs) were separated by electrophoresis and detected by laser-induced fluorescence on an automated gene sequencer. PCR parameters were optimized using an in vitro model community of known organisms. Community comparisons were made between deer fecal pellets, petroleum hydrocarbon-contaminated sands …
Impact Of Temperature Acclimation On Photosynthesis In The Toxic Red-Tide Dinoflagellate Alexandrium Fundyense (Ca28), Oscar Schofield, Joseph Grzymski, Mark A. Moline, Raffael J.M. Jovine
Impact Of Temperature Acclimation On Photosynthesis In The Toxic Red-Tide Dinoflagellate Alexandrium Fundyense (Ca28), Oscar Schofield, Joseph Grzymski, Mark A. Moline, Raffael J.M. Jovine
Biological Sciences
This study assessed the impact of temperature on the photosynthetic activity in the dinoflagellate Alexandrium fundyense (Ca28) for cultures grown at 75 µmol photons m–2 s–1 over a range of temperatures. Increasing light intensity under static temperatures caused a 5-fold decrease in the maximum quantum yield for photosystern II (PSII) (FvlFm) Carbon fixation rates mirrored high-light depressions in (FvlFm). Cells in the presence of streptomycin showed an 83% recovery in (FvlFm); therefore, only a minor proportion of the decline in (FvlFm)was attributable …
Photoadaptive Response During The Development Of A Coastal Antarctic Diatom Bloom And Relationship To Water Column Stability, Mark A. Moline
Photoadaptive Response During The Development Of A Coastal Antarctic Diatom Bloom And Relationship To Water Column Stability, Mark A. Moline
Biological Sciences
The ratio of the xanthophyll pigments diadinoxanthin and diatoxanthin to chlorophyll a [(DD + DT): Chl a] was used as a photoadaptive index during the development of a large Antarctic diatom bloom. This index was found to track fluctuations in the incident solar irradiance and the in situ light field over a 3-order-magnitude change in the water column biomass. Depth profiles of the (DD + DT): Chl a ratio showed that the upper mixed layer, assessed by physical data, was in fact stable over the course of the month. Diel experiments conducted over the same period showed a delayed …
A New Niche For Vibrio Logei, The Predominant Light Organ Symbiont Of Squids In The Genus Sepiola, Pat M. Fidopiastis, Sigurd Von Boletzky, Edward G. Ruby
A New Niche For Vibrio Logei, The Predominant Light Organ Symbiont Of Squids In The Genus Sepiola, Pat M. Fidopiastis, Sigurd Von Boletzky, Edward G. Ruby
Biological Sciences
Two genera of sepiolid squids—Euprymna, found primarily in shallow, coastal waters of Hawaii and the Western Pacific, and Sepiola, the deeper-, colder-water-dwelling Mediterranean and Atlantic squids—are known to recruit luminous bacteria into light organ symbioses. The light organ symbiont of Euprymna spp. is Vibrio fischeri, but until now, the light organ symbionts of Sepiola spp. have remained inadequately identified. We used a combination of molecular and physiological characteristics to reveal that the light organs of Sepiola affinis and Sepiola robusta contain a mixed population of Vibrio logei and V. fischeri, with V. logei comprising between …