Life Sciences Commons^™

Maturation Requirements For Dendritic Cells In T Cell Stimulation Leading To Tolerance Versus Immunity, Helen O'Neill, Jonathan Tan

Jonathan Tan

The model that dendritic cell (DC) "maturation" describes the change from an immature, antigen-capturing cell to a mature, antigen-presenting cell is well-established. Classification of DCs in terms of function has been problematic previously. It is therefore proposed that mature and not immature DCs are responsible for antigen presentation and stimulation of T cells. Furthermore, DC antigen presentation to T cells can have two outcomes: tolerance or immunity. The particular outcomes appear to be determined by the activation state of the mature DC. DCs can be activated by a range of environmental stimuli or "danger signals". Here, the hypothesis is advanced …

Taxomic Status Atelophryniscus Chrysophorus Mccranie, Wilson And Williams, 1989, (Anura Bufonidae) Inferred From Phylogeny, Edgar Lehr, Jennifer Pramuk

Edgar Lehr

The family Bufonidae is nearly cosmopolitan in distribution and contains 33 genera. The monotypic bufonid genus Atelophryniscus was described relatively recently from Honduras. This taxon was distinguished from Buto on the basis of its unusual gastromyzophorus tadpole. Stream-dwelling gastromyzophorus tadpoles are atypical within Bufonidae and when Atelophryniscus was described, this type of tadpole was unknown among members of the genus Buto. To investigate the phylogenetic placement of this taxon, we analyzed 83 previously published morphological characters for a sampling of Old and New World bufonids and included newly coded data. The data indicate that (1) there are no autapomorphies supporting …

Pfcg2, A Plasmodium Falciparum Protein Peripherally Associated With The Parasitophorous Vacuolar Membrane, Is Expressed In The Period Of Maximum Hemoglobin Uptake And Digestion By Trophozoites, Roland A. Cooper, Janni Papakrivos, Kristen D. Lane, Hisashi Fujioka, Klaus Lingelbach, Thomas E. Wellems

Roland A. Cooper

Analysis Of Andes Frogs (Phrynopus, Leptodactylidae, Anura) Phylogeny Based On 12s And 16s Mitochondrial Rdna Sequences, Edgar Lehr, Guido Fritzsche, Anke Muller

Edgar Lehr

South American leptodactylid frogs of the genus Phrynopus occur in cloud-forest, páramo, subpáramo and puna habitats (1000–4400 m elevation) from Colombia to Bolivia. Currently, there are 34 described species; however, many additional species new to science have been reported from Colombia, Peru, and Bolivia. The phylogeny of the species-diverse Phrynopus is unknown and the position of the genus within Leptodactylidae is poorly understood. We present the results of a phylogenetic study based on 12S and 16S mitochondrial rDNA. Fifteen species of Phrynopus from Bolivia to Ecuador are included, along with several other genera of Leptodactylidae and representatives of other frog …

A New Species Of Bufo (Anura Bufonidae) From Andean Peru, Edgar Lehr, Jennifer Pramuk, Mikael Lundberg

Edgar Lehr

A new species of Bufo tentatively assigned to the Bulo veraguensis group is described from forests near Paucartambo de Pasco, Peru, at elevations of 2600-3000 m in the Cordillera Oriental of central Peru. The new species differs from all known bufonids by having numerous large glands with many keratinous tips on the dorsum, large glands on the tibia and forearm, and two large dorsal glands lying between the parotoids. The new species is most similar to Bufa chavin. Both species are compared to each other and B. veraguensis with respect to external characters and skull osteology. The tadpole and call …

Barriers And Flow As Limiting Factors In The Spread Of An Invasive Crayfish (Procambarus Clarkii) In Southern California Streams, Jacob Kerby, Seth Riley, Lee Kats, Paul Wilson

Lee Kats

Invasive crayfish are a major threat to stream ecosystems, yet research has seldom identified successful ways of preventing their spread. Thirty-two stream sections were surveyed during 2000 and 2001 in the Santa Monica Mountains of southern California to determine the distribution of the invasive crayfish Procambarus clarkii. Streams with large barriers (waterfalls, culverts) often did not have crayfish present upstream of barriers. A mark-recapture study indicated that P. clarkii moved both up and downstream between pools, but that barriers significantly reduced movement between pools. Seasonal high flow velocities likely increase passive movement downstream and reduce movement upstream. Results indicate that …

Three New Species Of Phyrnopus From Central Peru (Amphibia Anura: Leptodactylidae), Edgar Lehr, Mikael Lundberg, Cesar Aguilar

Edgar Lehr

Three new species of Phrynopus (Anura: Leptodactylidae) are described from cloud forest and puna habitats in central Peruvian Departamento de Pasco between 3600 and 4390 m elevation, the latter is the highest known elevation of the genus. The new species have first finger shorter than second, vomerine teeth absent, and tympanic membrane and tympanic annulus absent, but differ in snout-vent length, skin texture, and coloration. Currently 37 species of Phrynopus are described, 26 (70.3%) of which are endemic to Peru.

A New Species Of The Eleutherodactylus Nigrovittatus Group (Anura: Leptodactylidae) From Andean Peru, Edgar Lehr

Edgar Lehr

No abstract provided.

Cgkb-Cyanogroup Genomics Knowledge Base, Tin-Chun Chu, Lee Lee, Shankar Srinivasan, John Gaynor, Quinn Vega, Bonnie Lustigman

Tin-Chun Chu, Ph.D.

No abstract provided.

Pfcrt Is More Than The Plasmodium Falciparum Chloroquine Resistance Gene: A Functional And Evolutionary Perspective, Roland A. Cooper, Carmony L. Hartwig, Michael T. Ferdig

Roland A. Cooper

Historical Analysis And Impact Of Ken Dryden’S The Game, Don Morrow

Donald Morrow

No abstract provided.

My Teaching Experience In Cambodia, Stephen Asma

Stephen T Asma

No abstract provided.

Effect Of Cadmium On The Growth Of Chlamydomonas, Suzen Awad, Tin-Chun Chu, Bonnie Lustigman, Lee Lee

Tin-Chun Chu, Ph.D.

No abstract provided.

A Literary Analysis Of Ken Dryden’S The Game.”, Don Morrow

Donald Morrow

No abstract provided.

Plethodon Albagula (Western Slimy Salamander), Vocalization, Joseph Milanovich

Joseph Milanovich

No abstract provided.

Sport In Canada: A History, Donald Morrow, Kevin Wamsley

Donald Morrow

No abstract provided.

Diadophis Punctatus Sticktogenys (Mississippi Ringneck Snake), Diet, Joseph Milanovich

Joseph Milanovich

No abstract provided.

Talking Politics And Engaging Politics: An Examination Of The Interactive Relationships Between Structural Features Of Political Talk And Discussion Engagement, Ann Williams

Ann E Williams

This study takes a process-oriented approach to understand the current status of political discussion research and identifies discussion engagement—discussion attention and integrative discussion—as an unexplored but important facet of political discussion. As a block, these two variables of discussion engagement independently accounted for significant variance in two criterion variables of political engagement, political knowledge and political participation, after controlling for not only a host of demographic, attitudinal, and media use variables but also three most researched structural features of political discussion—network size, discussion frequency, and network heterogeneity. In addition, the study analyzes the interplay between various attributes of political discussion …

The Immunogenicity Of Dendritic Cell-Derived Exosomes, Ben Quah, Helen O'Neill

Helen O'Neill

Exosome production represents an alternate endocytic pathway for secretion. Multivesicular endosomes (MVE) fuse with the plasma membrane expelling internal vesicles or exosomes from cells. Exosome production has been recently described for immune cells including B cells, dendritic cells (DC), mast cells, macrophages and T cells. Exosomes derived from some DC populations stimulate T lymphocyte proliferation in vitro and have potent capacity to generate anti-tumour immune responses in vivo. These reported studies have involved in vitro grown mature DC expanded from precursors with cytokines. However, immature DC produce higher numbers of exosomes than mature DC and this is thought to be …

Sonora Semiannulata (Ground Snake), Geographic Distribution And Range Extension, Joseph Milanovich

Joseph Milanovich

No abstract provided.

The Atlas Mountains, Not The Strait Of Gibraltar, As A Biogeographic Barrier For Mauremys Leprosa (Reptilia: Testudines), Edgar Lehr, Uwe Fritz, Guido Fritzsch, Jean-Marc Ducotterd, Anke Muller

Edgar Lehr

Sequence data of the mitochondrial cytochrome b gene of stripe-necked terrapins (Mauremys leprosa) have been compared from localities north and south of the Atlas Mts . (Ceuta; Morocco) and from Donana National Park (Spain). A low maximum sequence divergence (approximately I %) corresponds to two major clades; one is re presented by localities to the north of the Atlas Mts. and in Dofiana National Park and the other by localities to the south of the Atlas Mts. Differentiation between populations north and south of the Atlas Mts. is much more pronounced than that found between samples from each side of …

Maturation Requirements For Dendritic Cells In T Cell Stimulation Leading To Tolerance Versus Immunity, Helen O'Neill, Jonathan Tan

Helen O'Neill

The model that dendritic cell (DC) "maturation" describes the change from an immature, antigen-capturing cell to a mature, antigen-presenting cell is well-established. Classification of DCs in terms of function has been problematic previously. It is therefore proposed that mature and not immature DCs are responsible for antigen presentation and stimulation of T cells. Furthermore, DC antigen presentation to T cells can have two outcomes: tolerance or immunity. The particular outcomes appear to be determined by the activation state of the mature DC. DCs can be activated by a range of environmental stimuli or "danger signals". Here, the hypothesis is advanced …

Resurrection Of The Stenocercus Torquatus Boulenger, A Spiny-Tailed Iguanid Lizard (Squamata: Iguania) From Peru, Edgar Lehr, Mikael Lundberg, Omar Torres-Carvajal

Edgar Lehr

We resurrect and redescribe Stenocercus torquatus from the Andes of central Peru in departamentos JUnln and Pasco at elevations between 800 and 1800 m. This species was erroneously synonymized with Stenocercus crassicaudatus, which occurs allopatrically in the Andes of southeastern Peru, departamento Cusco. In addition to several scale counts, Stenocercus torquatus differs from S. crassicaudatus in having a black antehumeral collar, two black transverse bands anterior to the antehumeral collar, a shorter tail, the ability to change color, and an arboreal life-style.

Effects Of Urbanization On The Distribution And Abundance Of Amphibians And Invasive Species In Southern California Streams, Seth Riley, Gary Busteed, Lee Kats, Thomas Vandergon, Lena Lee, Rosi Dagit, Jacob Kerby, Robert Fisher, Raymond Sauvajot

Lee Kats

Urbanization negatively affects natural ecosystems in many ways, and aquatic systems in particular. Urbanization is also cited as one of the potential contributors to recent dramatic declines in amphibian populations. From 2000 to 2002 we determined the distribution and abundance of native amphibians and ex- otic predators and characterized stream habitat and invertebrate communities in 35 streams in an urbanized landscape north of Los Angeles (U.S.A.). We measured watershed development as the percentage of area within each watershed occupied by urban land uses. Streams in more developed watersheds often had exotic crayfish ( Procambarus clarkii) and fish, and had fewer …

Vh Gene Usage In Humans: Biased Usage Of The Vh6 Gene In Immature B Lymphoid Cells, Jeffrey Berman, Katherine Nickerson, Roberta Pollock, Jeremy Barth, Ruud Schuurman, Daniel Knowles, Leonard Chess, Frederick Alt

Roberta Pollock

No abstract provided.

Which Drugs Cause Cancer? Animal Tests Yield Misleading Results, Andrew Knight, Jarrod Bailey, Jonathan P. Balcombe

Jonathan Balcombe, Ph.D.

No abstract provided.