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Selected Works

2007

Articles 1 - 14 of 14

Full-Text Articles in Life Sciences

Non-Standard Sources In A Standardized World: Responsible Practice And Ethics Of Acquiring Turtle Specimens For Scientific Use, Edgar Lehr, Russell Burke, Linda Ford, Steve Mockford, Peter Pritchard, Jose Rosado, Darrell Senneke, Bryan Stuart Nov 2007

Non-Standard Sources In A Standardized World: Responsible Practice And Ethics Of Acquiring Turtle Specimens For Scientific Use, Edgar Lehr, Russell Burke, Linda Ford, Steve Mockford, Peter Pritchard, Jose Rosado, Darrell Senneke, Bryan Stuart

Edgar Lehr

No abstract provided.

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Life History And Courtship Behavior Of Black Perch, Embiotoca Jacksoni (Teleostomi: Embiotocidae), From Southern California, Bridgette Froeschke, Larry Allen, Daniel Pondella Sep 2007

Life History And Courtship Behavior Of Black Perch, Embiotoca Jacksoni (Teleostomi: Embiotocidae), From Southern California, Bridgette Froeschke, Larry Allen, Daniel Pondella

Daniel Pondella

The black perch, Embiotoca jacksoni Agassiz, 1853, is a common reef fish associated with nearshore marine habitats of California, with the majority of the population occurring within the Southern California Bight. Black perch were collected throughout southern California from Santa Barbara to Carlsbad, including Santa Catalina Island, to determine their physical characteristics, growth, sex ratio, periodicity of reproduction, and length of gestation. Courtship observations were conducted using scuba along the King Harbor Breakwater in Redondo Beach, California, from January 2004 to December 2005 to verify periodicity of courting and associated reproductive behaviors. Specimens captured ranged from 75 to 220 mm …

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Bactericidal Efficacy Of Liposomal Aminoglycosides Against Burkholderia Cenocepacia, Ali Azghani Jul 2007

Bactericidal Efficacy Of Liposomal Aminoglycosides Against Burkholderia Cenocepacia, Ali Azghani

Ali Azghani

Objectives Burkholderia cenocepacia (formally a genotype of Burkholderia cepacia complex called genomovar III) has emerged as a serious opportunistic pathogen in individuals with cystic fibrosis. We developed a liposomal antibiotic formulation composed of 1,2-distearoyl-sn-glycero-3-phosphocholine and cholesterol (molar ratio 2:1) to overcome B. cenocepacia's resistance to commonly used aminoglycosidic antibiotics.
Methods The dehydration-rehydration vesicles technique was used to entrap antibiotics in liposomes. The size of liposome formulations was measured and encapsulation efficiencies were determined by microbiological assays. MICs of free and liposomal antibiotics against the clinical isolates of B. cenocepacia were determined by the standard broth …

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Structure And Function Of Haemocytes In Two Marine Gastropods, Megathura Crenulata And Aplysia Californica., Gary Martin, Christopher Oates, Heather Tousignant, Heather Crabtree, Rachel Yamakawa Jul 2007

Structure And Function Of Haemocytes In Two Marine Gastropods, Megathura Crenulata And Aplysia Californica., Gary Martin, Christopher Oates, Heather Tousignant, Heather Crabtree, Rachel Yamakawa

Gary Martin

Aplysia californica is an important mollusc for neurobiological research and Megathura crenulata is becoming valuable as the source of keyhole limpet haemocyanin (KLH) which shows promise in treating cancer, allergy and immunosuppression. The culture of these animals provides opportunities to assess their physiological responses to stress and disease. Molluscan haemocytes are known to be involved in a variety of physiological responses, yet the haemocytes of this opisthobranch and vetigastropod have not been characterized. The purpose of this study is to describe the morphology of these cells and summarize their functions based on a suite of assays previously developed on other …

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Tailed Forisomes Of Canavalia Gladiata: A New Model To Study Ca2+-Driven Protein Contractility, Winfried Peters, Michael Knoblauch, Stephen Warmann, Reinhard Schnetter, Amy Shen, William Pickard Jun 2007

Tailed Forisomes Of Canavalia Gladiata: A New Model To Study Ca2+-Driven Protein Contractility, Winfried Peters, Michael Knoblauch, Stephen Warmann, Reinhard Schnetter, Amy Shen, William Pickard

Winfried S. Peters

Background and Aims Forisomes are Ca2+-dependent contractile protein bodies that form reversible plugs in sieve tubes of faboid legumes. Previous work employed Vicia faba forisomes, a not entirely unproblematic experimental system. The aim of this study was to seek to establish a superior model to study these intriguing actuators.
Methods Existing isolation procedures were modified to study the exceptionally large, tailed forisomes of Canavalia gladiata by differential interference contrast microscopy in vitro. To analyse contraction/expansion kinetics quantitatively, a geometric model was devised which enabled the computation of time-courses of derived parameters such as forisome volume from simple parameters readily determined …

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Antioxidants Preserve Macrophage Phagocytosis Of Pseudomonas Aeruginosa During Hyperoxia, Ali Azghani Apr 2007

Antioxidants Preserve Macrophage Phagocytosis Of Pseudomonas Aeruginosa During Hyperoxia, Ali Azghani

Ali Azghani

Pseudomonas. aeruginosa (PA) is a leading cause of nosocomial pneumonia in patients receiving mechanical ventilation with hyperoxia. Exposure to supraphysiological concentrations of reactive oxygen species during hyperoxia may result in macrophage damage that reduces their ability to phagocytose PA. We tested this hypothesis in cultured macrophage-like RAW 264.7 cells and alveolar macrophages from mice exposed to hyperoxia. Exposure to hyperoxia induced a similarly impaired phagocytosis of both the mucoid and the nonmucoid forms of PA in alveolar macrophages and RAW cells. Compromised PA phagocytosis was associated with cytoskeleton disorganization and actin oxidation in hyperoxic macrophages. To test whether moderate concentrations …

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Reversible Birefringence Suggests A Role For Molecular Self-Assembly In Forisome Contractility, Winfried Peters, Reinhard Schnetter, Michael Knoblauch Apr 2007

Reversible Birefringence Suggests A Role For Molecular Self-Assembly In Forisome Contractility, Winfried Peters, Reinhard Schnetter, Michael Knoblauch

Winfried S. Peters

Forisomes are contractile protein bodies that control the effective diameter of the sieve elements of the faboid legumes by reversible, Ca2+-driven changes of shape. Forisomes consist of fibrils; we inferred from available electron-microscopical data (which necessarily provide images of fixed, non-functional forisomes) that a reversible assembly of ordered fibrillar arrays might be involved in the contractile mechanism. Here we examined functional forisomes isolated from Vicia faba L. by differential interference contrast microscopy and polarisation microscopy. We found them birefringent in the longitudinally expanded but not in the contracted state, showing ‘parallel extinction’ with the direction of vibration of the slow …

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Med19(Rox3) Regulates Intermodule Interactions In The Saccharomyces Cerevisiae Mediator Complex., Shamara Baidoobonso, Benjamin Guidi, Lawrence Myers Feb 2007

Med19(Rox3) Regulates Intermodule Interactions In The Saccharomyces Cerevisiae Mediator Complex., Shamara Baidoobonso, Benjamin Guidi, Lawrence Myers

Shamara M Baidoobonso, PhD

The Saccharomyces cerevisiae Mediator is a 25-subunit complex that facilitates both transcriptional activation and repression. Structural and functional studies have divided Mediator subunits into four distinct modules. The Head, Middle, and Tail modules form the core functional Mediator complex, whereas a fourth, the Cyc-C module, is variably associated with the core. By purifying Mediator from a strain lacking the Med19(Rox3) subunit, we have found that a complex missing only the Med19(Rox3) subunit can be isolated under mild conditions. Additionally, we have established that the entire Middle module is released when the Deltamed19(rox3) Mediator is purified under more stringent conditions. In …

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Taxonomy, Life History, And Population Sex Ratios Of North American Dasineura (Diptera: Cecidomyiidae) On Goldenrods (Asteraceae), Warren Abrahamson, N. Dorchin, C.E. Clarkin, E.R. Scott, M.P. Luongo Dec 2006

Taxonomy, Life History, And Population Sex Ratios Of North American Dasineura (Diptera: Cecidomyiidae) On Goldenrods (Asteraceae), Warren Abrahamson, N. Dorchin, C.E. Clarkin, E.R. Scott, M.P. Luongo

Warren G. Abrahamson, II

No abstract provided.

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Hydroperiod And Metamorphosis In The Small-Mouthed Salamander Dec 2006

Hydroperiod And Metamorphosis In The Small-Mouthed Salamander

Travis J. Ryan

Ambystoma texanum (Small-mouthed Salamander) breeds primarily in temporary wetlands, and while natural history studies have suggested a minimum larval period of about 2 mo, it is not clear how hydroperiod (the length of time that a temporary wetland holds water) infl uences populations. I conducted a mesocosm experiment to investigate the effects of hydroperiod on the completion of metamorphosis, as well as age and size at metamorphosis. I used hydroperiods of 50, 75, and 100 d, and a non-drying treatment as a control. Survival to the end of each hydroperiod was consistent among all groups, but no individuals completed metamorphosis …

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Water Uptake By Older Roots: Evidence From Desert Succulents, Gretchen North, E. Baker Dec 2006

Water Uptake By Older Roots: Evidence From Desert Succulents, Gretchen North, E. Baker

Gretchen North

Desert succulents are renowned for their rapid recovery of shoot function after periods of drought as a result of shoot succulence, root–shoot interactions, and key root properties. Near the base of the shoot, the proximal (generally older) roots appear to play a major role in the rapid uptake and delivery of water, especially after a period of soil drying when the rest of the root system has a lower hydraulic conductance. In all of the cacti, agaves, and yuccas examined to date, hydraulic conductance for the proximal root zone is unexpectedly high. Substantial water uptake by older roots of cacti …

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Legacy Of Land Use In Southern Appalachian Forests: Effects On Terrestrial Salamander Abundance Along Edges And Within Abandoned Logging Roads, R. Semlitsch,, Travis Ryan, M. Chatfield, B. Drehman, K. Hamed, N. Pekarek, M. Spath Dec 2006

Legacy Of Land Use In Southern Appalachian Forests: Effects On Terrestrial Salamander Abundance Along Edges And Within Abandoned Logging Roads, R. Semlitsch,, Travis Ryan, M. Chatfield, B. Drehman, K. Hamed, N. Pekarek, M. Spath

Travis J. Ryan

Roads may be one of the most common disturbances in otherwise continuous forested habitat in the southern Appalachian Mountains. Despite their obvious presence on the landscape, there is limited data on the ecological effects along a road edge or the size of the “road-effect zone.” We sampled salamanders at current and abandoned road sites within the Nantahala National Forest, North Carolina (U.S.A.) to determine the road-effect zone for an assemblage of woodland salamanders. Salamander abundance near the road was reduced significantly, and salamanders along the edges were predominantly large individuals. These results indicate that the road-effect zone for these salamanders …

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Effects Of Resource Availability On Tolerance Of Herbivory: A Review And Assessment Of Three Opposing Models, Warren Abrahamson, M.J. Wise Dec 2006

Effects Of Resource Availability On Tolerance Of Herbivory: A Review And Assessment Of Three Opposing Models, Warren Abrahamson, M.J. Wise

Warren G. Abrahamson, II

No abstract provided.

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Fisheries Independent Assessment Of A Returning Fishery: Abundance Of Juvenile White Seabass (Atractoscion Nobilis) In The Shallow Nearshore Waters Of The Southern California Bight, 1995–2005, Larry G. Allen, Daniel J. Pondella Ii, Michael A. Shane Dec 2006

Fisheries Independent Assessment Of A Returning Fishery: Abundance Of Juvenile White Seabass (Atractoscion Nobilis) In The Shallow Nearshore Waters Of The Southern California Bight, 1995–2005, Larry G. Allen, Daniel J. Pondella Ii, Michael A. Shane

Daniel Pondella

Nearshore, coastal and embayment areas off southern California were sampled to determine the spatial and temporal patterns abundance and size distributions of young white seabass in the shallow (5–14 m) waters from Santa Barbara south to Imperial Beach off San Diego. A total of 19 stations, 13 in nearshore coastal waters and 6 in embayments, dispersed along the Southern California Bight were surveyed in each sampling month using 45.7 m variable mesh, monofilament gill nets. In the 11-year period of sampling (April 1995–June 2005), a total of 8075 juvenile white seabass was captured in 42 sampling months. The mean catch-per-unit-effort …

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