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Full-Text Articles in Life Sciences

Speciation In The Central American Seaway: The Importance Of Taxon Sampling In The Identification Of Trans-Isthmian Geminate Pairs, Matthew T. Craig, Philip A. Hastings, Daniel J. Pondella Ii May 2004

Speciation In The Central American Seaway: The Importance Of Taxon Sampling In The Identification Of Trans-Isthmian Geminate Pairs, Matthew T. Craig, Philip A. Hastings, Daniel J. Pondella Ii

Daniel Pondella

Aim  To create a molecular phylogenetic hypothesis for the closely related serranid genera Alphestes Bloch and Schneider and Dermatolepis Gill and assess the role of the Panamanian Isthmus in speciation within these reef fishes. Location  Tropical eastern Pacific, Caribbean, and Indian Oceans. Methods  Sequence data from one nuclear (TMO-4C4) and three mitochondrial genes (16S, 12S, and cytochrome b) were used in maximum parsimony and maximum likelihood analyses. Results  Here we show that previously hypothesized trans-isthmian geminate species are not each other's closest living relatives. Species of Alphestes Bloch and Schneider in the eastern Pacific are sister taxa indicating post-closure speciation. …


Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko May 2004

Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko

Pr. Mamoudou H. DICKO, PhD

The latest estimates of the FAO demonstrate the problems of the fight against hunger. These problems are manifested by the ever-increasing number of chronically undernourished people worldwide. Their numbers during the 1999-2001 period were estimated at about 840 million of which 798 million live in developing countries. Sub-Saharan Africa alone represented 198 million of those. In this part of Africa the prevalence of undernourishment ranges from 5-34%, causing growth retardation and insufficient weight gain among one third of the children under five years of age and resulting in a mortality of 5-15% among these children. Malnutrition resulting from undernourishment is …


A Major Evolutionary Transition To More Than Two Sexes?, Joel D. Parker Feb 2004

A Major Evolutionary Transition To More Than Two Sexes?, Joel D. Parker

Joel D Parker

Two recently discovered cases of genetic caste determination in social insects might provide the first example of a major evolutionary transition from two to more than two sexes. I argue here that the system can be interpreted as comprising primarily individuals requiring gametes from three parental types and having four sexes from the perspective of demographic extinction. Additionally, I show how this mating system can be seen as a major evolutionary transition. For these populations, it is apparent that the mechanism for a three- or four-sex system does not lie within the myriad of possible arrangements of chromosomes within individuals, …


Molecular Phylogenetic Evidence For An Extracellular Cu Zn Superoxide Dismutase Gene In Insects, Joel D. Parker Jan 2004

Molecular Phylogenetic Evidence For An Extracellular Cu Zn Superoxide Dismutase Gene In Insects, Joel D. Parker

Joel D Parker

Representatives of three ancient gene families of the antioxidant enzyme superoxide dismutase (SOD) can be found in most metazoans. In mammals and Caenorhabditis elegans , there is at least one gene each of the cytoplasmic, mitochondrial and extracellular lineages of SOD genes. The cytoplasmic SOD was one of the first enzymes to be implicated in ageing due to its protection against damaging oxygen free radicals. In contrast to other metazoans, insects were thought to lack a gene for the extracellular SOD. We have cloned and sequenced an SOD mRNA in the ant Lasius niger that appears to belong to this …


Low Cost Seismic Test Platform, David A. Bainbridge Jan 2004

Low Cost Seismic Test Platform, David A. Bainbridge

David A Bainbridge

The challenge of seismic safety is better testing of building systems rather than just components. This mobile test platform may offer an inexpensive method of testing building performance.


Dramatic Decline Of Wild South China Tigers Panthera Tigris Amoyensis: Field Survey Of Priority Tiger Reserves, Ronald Tilson, Hu Defu, Jeff Muntifering, Philip J. Nyhus Jan 2004

Dramatic Decline Of Wild South China Tigers Panthera Tigris Amoyensis: Field Survey Of Priority Tiger Reserves, Ronald Tilson, Hu Defu, Jeff Muntifering, Philip J. Nyhus

Philip J. Nyhus

This paper describes results of a Sino- American field survey seeking evidence of South China tigers Panthera tigris amoyensis in the wild. In 2001 and 2002 field surveys were conducted in eight reserves in five provinces identified by government authorities as habitat most likely to contain tigers. The surveys evaluated and documented evidence for the presence of tigers, tiger prey and habitat disturbance. Approximately 290 km of mountain trails were evaluated. Infrared remote cameras set up in two reserves captured 400 trap days of data. Thirty formal and numerous informal interviews were conducted with villagers to document wildlife knowledge, livestock …


'Willa Cather’S ‘River Of Silver Sound’: Woman As Ecosystem In The Song Of The Lark, Matthew Sivils Jan 2004

'Willa Cather’S ‘River Of Silver Sound’: Woman As Ecosystem In The Song Of The Lark, Matthew Sivils

Matthew Sivils

Willa Cather loved the Southwest. The landscapes and cu ltural history of the area held a prominent place in both her fiction and in her own creative consciousness.1 As Judith Fryer points out, after Cather visited New Mexico and Arizona in 1912, she became so enamored with the region that she returned many times over the fol lowing decade (41). During this period Cather published a novel heavily inspired by her affection for the Southwestern landscape-The Song of the Lark. This novel fol lows Thea Kronborg from her childhood in the fictional rural town of Moonstone, Colorado, through an artistic …


Concepts Of Bacterial Biodiversity For The Age Of Genomics, Frederick M. Cohan Dec 2003

Concepts Of Bacterial Biodiversity For The Age Of Genomics, Frederick M. Cohan

Frederick M. Cohan

No abstract provided.