Digital Commons Network^™

Biomimetic Actuators: Where Technology And Cell Biology Merge [Review Article], Michael Knoblauch, Winfried Peters

Winfried S. Peters

Comments On Eusopondis And Proctoporus (Squamata: Gymnophthalmidae) From Peru, With The Description Of Three New Species And A Key To The Peruvian Species, Edgar Lehr, Gunther Kohler

Edgar Lehr

We describe two new species of Proctoporus and a new species of Euspondylus (all from central Peru, Departamento de Huanuco, 2545 to 3010 m elevation). The new species are distinguished from all species presently assigned to Proctoporus and Euspondylus by unique characteristics of pholidosis, morphometrics, and color pattern. A key to the Peruvian species of Proctoporus and Euspondylus is provided. The current allocation of species to Proctoporus and Euspondylus may not reflect the phylogenetic relationships of the species under consideration. Based on the available data there appears to be no evidence to justify the separation of these genera. However, because …

Photo- And Electropatterning Of Hydrogel-Encapsulated Living Cell Arrays, Dirk Albrecht, Valerie Tsang, Robert Sah, Sangeeta Bhatia

Dirk R. Albrecht

Living cells have the potential to serve as sensors, naturally integrating the response to stimuli to generate predictions about cell fate (e.g., differentiation, migration, proliferation, apoptosis). Miniaturized arrays of living cells further offer the capability to interrogate many cells in parallel and thereby enable high-throughput and/or combinatorial assays. However, the interface between living cells and synthetic chip platforms is a critical one wherein the cellular phenotype must be preserved to generate useful signals. While some cell types retain tissue-specific features on a flat (2-D) surface, it has become increasingly apparent that a 3-D physical environment will be required for others. …

Lateral Hypothalamic Signaling Mechanisms Underlying Feeding Stimulation: Differential Contributions Of Src Family Tyrosine Kinases To Feeding Triggered Either By Nmda Injection Or By Food Deprivation, Arshad Khan, Herman H. Cheung, Elizabeth R. Gillard, Jennifer A. Palarca, Derek S. Welsbie, James W. Gurd, B. Glenn Stanley

Arshad M. Khan, Ph.D.

No abstract provided.

Rhodobacter Capsulatus Porphobilinogen Synthase, A High Activity Metal Ion Independent Hexamer, David W. Bollivar, Cheryl Clauson, Rachel Lighthall, Siiri Forbes, Bashkim Kokona, Robert Fairman, Lenka Kundrat, Eileen K. Jaffe

David Bollivar

Background: The enzyme porphobilinogen synthase (PBGS), which is central to the biosynthesis of heme, chlorophyll and cobalamins, has long been known to use a variety of metal ions and has recently been shown able to exist in two very different quaternary forms that are related to metal ion usage. This paper reports new information on the metal ion independence and quaternary structure of PBGS from the photosynthetic bacterium Rhodobacter capsulatus. Results: The gene for R. capsulatus PBGS was amplified from genomic DNA and sequencing revealed errors in the sequence database. R. capsulatus PBGS was heterologously expressed in E. coli and …

Evidence For And Characterization Of Ca2+ Binding To The Catalytic Region Of Arabidopsis Thaliana Phospholipase Dβ, Xuemin Wang

Xuemin (Sam) Wang

Embryonic Expression Of Pre-Initiation Dna Replication Factors In Xenopus Laevis, Brian Walter, Jonathan Henry

Brian Walter

We examined the expression of various DNA replication factors, including: cdc45, the factors of the GINS heterotetramer (Sld5, Psf1, Psf2, Psf3), and PCNA, in Xenopus laevis during embryonic development via whole mount in situ hybridization. For the most part, these factors were expressed in similar patterns, with some subtle variations, throughout development within the anterior CNS, pharyngeal arches, and various placodes. More significant variations were also observed, including expression of only Psf1 and Psf2 in the pronephros and unique Psf2 expression in the somitic mesoderm. Overall, these results suggest that common regulatory mechanisms are involved in the transcriptional deployment of …

Is There An Antipredator Blood-Squirting Defense In The Bull Horned Lizard, Phrynosoma Taurus?, George Middendorf

George Middendorf

No abstract provided.

Jual Obat Bius Di Makasar 082313333253 Alamat Apotik Jual Obat Tidur / Bius Di Makasar, Toko Afeng Obat Kuat Bogor

toko afeng obat kuat bogor

Thermal And Sodium Dodecylsulfate Induced Transitions Of Streptavidin, Mark Waner, Irina Navrotskaya, Amanda Bain, Edward Oldham, David Mascotti

David P. Mascotti

The strong specific binding of streptavidin (SA) to biotin is utilized in numerous biotechnological applications. The SA tetramer is also known to exhibit significant stability, even in the presence of sodium dodecylsulfate (SDS). Despite its importance, relatively little is known about the nature of the thermal denaturation pathway for SA. This work uses a homogeneous SA preparation to expand on the data of previous literature reports, leading to the proposal of a model for temperature induced structural changes in SA. Temperature dependent data were obtained by SDS and native polyacrylamide gel electrophoresis (PAGE), differential scanning calorimetry (DSC), and fluorescence and …

The Multidisciplinary Influence Of Common Sustainability Indices, Audrey L. Mayer, Hale W. Thurston, Christopher W. Pawlowski

Audrey Mayer

The Functions Of Animal Micrornas., Victor Ambros

Victor R. Ambros

MicroRNAs (miRNAs) are small RNAs that regulate the expression of complementary messenger RNAs. Hundreds of miRNA genes have been found in diverse animals, and many of these are phylogenetically conserved. With miRNA roles identified in developmental timing, cell death, cell proliferation, haematopoiesis and patterning of the nervous system, evidence is mounting that animal miRNAs are more numerous, and their regulatory impact more pervasive, than was previously suspected.

'Mass Delusion' Or 'True Myth'? Pbs Considers The Question Of God, Stephen Asma

Stephen T Asma

The Question of God is a new 4-hour miniseries from PBS. It is based on a long-running course taught by Harvard University psychiatry professor Armand Nicholi that compares the biographies and theories of Sigmund Freud, skeptic, and C. S. Lewis, believer. On balance, the miniseries succeeds as an introduction to complex issues.

A Spiroplasma Associated With Tremor Disease In The Chinese Mitten Crab (Eriocheir Sinensis), Wen Wang, Bohai Wen, Gail E. Gasparich, Ningning Zhu, Liwen Rong, Jianxiu Chen, Zaikuan Xu

Gail Gasparich

Receptivity For Probiotic Products Among Pre-Menopausal Female Students In An African University, Kingsley Anukam, Emmanuel Osazuwa, Gregor Reid, Melanie Katsivo

Kingsley C Anukam

OBJECTIVE: The objective of this study was to examine the receptivity for probiotic products among premenopausal female students in an African university. GOAL: The goal of this study was to determine the local knowledge in Nigeria of probiotics and the willingness of young women to use them should they be introduced. STUDY: Closed-ended questionnaires were administered to a sample of 280 participants and these addressed age, marital status, perceived risk of HIV infection for the next 3 years, and history of urogenital infections. The participants were also asked whether they would welcome a probiotic product in oral/vaginal form and in …

Size And Organic Content Of Eggs Of Marine Annelids, And The Underestimation Of Egg Energy Content By Dichromate Oxidation, William Jaeckle, Bruno Pernet

William Jaeckle

Dichromate oxidation is a simple technique that is often used to estimate the energy content of eggs in studies of marine invertebrate life histories (1). We used this method to measure the energy contents of the eggs of 12 species of marine annelids. In combination with measures of egg ash-free dry weight (AFDW), these data yielded estimates of AFDW-specific energy density that were mostly lower than the average weight-specific energy density of carbohydrates. This seemed unlikely to be correct, as invertebrate eggs typically contain little carbohydrate and instead are composed primarily of energy-dense protein and lipid (1, 2). After validating …

Application Of Response Surface Methodology For Studying The Product Characteristics Of Extruded Rice-Cowpea-Groundnut Blends, Emmanuel Asare, Samuel Sefa-Dedeh, Emmanuel Ohene Afoakwa

Professor Emmanuel Ohene Afoakwa

Response surface methodology (with central composite rotatable design for k=3 was used to investigate the product properties of extruded rice-cowpea-groundnut blends in a single screw extruder. The combined effect of cowpea (0-20%), groundnut (0-10%), and feed moisture (14-48%) levels were used for formulation of the products. The product moisture, expansion ratio, bulk density and total colour change were studied using standard analytical methods. Well-expanded rice-legume blend extrudates of less bulk density and lower moisture content were produced at low feed moisture. Increasing legume addition affected the various shades of colour in the product. Models developed for the indices gave R2 …

The Microflora Of Fermented Nixtamalized Corn, Samuel Sefa-Dedeh, Beatrice Cornelius, Wisdom Amoa-Awua, Esther Sakyi-Dawson, Emmanuel Ohene Afoakwa

Professor Emmanuel Ohene Afoakwa

Nixtamalization is a traditional process that improves the nutritional quality of corn. To provide a means of utilizing the nutritional benefits of nixtamalized corn and improve product acceptability, lactic acid fermentation was applied. The objective of the study was to study the microbial profile and establish the important lactobacilli of fermenting nixtamalized corn dough. Two batches of cleaned whole corn were subjected to the process of nixtamalization, using two concentrations of lime (0.5 or 1.0%), milled, made into a dough (50% moisture) and fermented spontaneously for 72 h. A control sample was prepared without alkaline treatment. pH and titratable acidity …

Osedax: Bone-Eating Marine Worms With Dwarf Males, G W. Rouse, Shana K. Goffredi, R C. Vrijenhoek

Shana Goffredi

We describe a new genus, Osedax, and two new species of annelids with females that consume the bones of dead whales via ramifying roots. Molecular and morphological evidence revealed that Osedax belongs to the Siboglinidae, which includes pogonophoran and vestimentiferan worms from deep-sea vents, seeps, and anoxic basins. Osedax has skewed sex ratios with numerous dwarf (paedomorphic) males that live in the tubes of females. DNA sequences reveal that the two Osedax species diverged about 42 million years ago and currently maintain large populations ranging from 105 to 106 adult females.

Vibrio Parahaemolyticus And V. Harveyi Cause Detachment Of The Epithelium From The Midgut Trunk Of The Penaeid Shrimp, Sicyonia Ingentis., Gary G. Martin, Nicole Rubin, Erica Swanson

Gary Martin

Shrimp Sicyonia ingentis were either injected with Vibrio parahaemolyticus (104 CFU) or V. harveyi (106 CFU) or immersed in ASW containing either species at 105 CFU ml-1. These densities were shown in preliminary experiments to kill approximately half the population by 7 d. On Day 7, surviving shrimp were classified as either diseased or apparently healthy, and their midgut trunks (MGT) were examined by light and electron microscopy. All shrimp immersed in ASW containing either species of Vibrio showed detachment of the epithelium in the MGT. In shrimp injected with either species of Vibrio, epithelial detachment was common in diseased …

The Neurobiology Of Antiepileptic Drugs, Michael Rogawski, Wolfgang Löscher

Michael A. Rogawski

Antiepileptic drugs (AEDs) provide satisfactory control of seizures for most patients with epilepsy. The drugs have the remarkable ability to protect against seizures while permitting normal functioning of the nervous system. AEDs act on diverse molecular targets to selectively modify the excitability of neurons so that seizure-related firing is blocked without disturbing non-epileptic activity. This occurs largely through effects on voltage-gated sodium and calcium channels, or by promoting inhibition mediated by GABA-A (γ-aminobutyric acid, type A) receptors. The subtle biophysical modifications inchannel behaviour that are induced by AEDs are often functionally opposite to defects in channel properties that are caused …

Responses Of Kit Foxes (Vulpes Macrotis) To Antipredator Blood-Squirting And Blood Of Texas Horned Lizards (Phrynosoma Cornutum), Wade Sherbrooke, George Middendorf, M E. Douglas

George Middendorf

Effects Of Cowpea Fortification, Dehydration Method And Storage Time On Some Quality Characteristics Of Maize-Based Traditional Weaning Foods., Emmanuel Ohene Afoakwa, Samuel Sefa-Dedeh, Esther Sakyi-Dawson

Professor Emmanuel Ohene Afoakwa

Fortification of cereal-based traditional foods with legume protein can improve their nutritional value. It is, however, important to find out the extent to which the addition of cowpea affects the desirable quality characteristics of traditional weaning foods prepared from fermented maize and also to assess the effect of dehydration method and storage time on the chemical, physico-chemical and functional properties of the products. A 3 x 2 x 4 factorial experiment with cowpea level, drying method and storage time as the respective variables was done. The traditional weaning food was prepared by steeping maize in water for 24 hours, mixed …

Two New Species Of Marsupial Frogs (Anura: Hylidae: Gastrotheca) From The Cordillera Oriental In Central Peru, Edgar Lehr, William E. Duellman, Daniel Rodriguez, Rudolf Von May

Edgar Lehr

A distinctive new species of Gastrotheca from the Rio Chanchamayo Valley in the Cordillera Oriental in Peru is the only known member of the genus that lacks a tympanum. Another new species from the Cordillera de Carpish is distinctive in having a pair of lateral brood pouches and only basal webbing on the foot.

Protein S-Glutathionylation In Retinal Pigment Epithelium Converts Heat Shock Protein 70 To An Active Chaperone., George Hoppe, Yuh-Cherng Chai, J. Crabb, Jonathan Sears

Yuh-Cherng Chai

A disulfide bond between key redox-sensitive cysteine residues and glutathione is one mechanism by which redox related allosteric effectors can regulate protein structure and function. Here we test the hypothesis that glutaredoxin-1 (Grx-1), a member of the oxidoreductase family of enzymes, may be a critical component of redox-sensitive molecular switches by mediating reversible protein S-glutathionylation and enzymatic catalysis of thiol/disulfide exchange. Deglutathionylation of a 70 kDa protein by Grx-1 was detected using a monoclonal antibody specific to protein S-glutathionylation. Heat shock cognate protein 70 (Hsc70) was identified as a substrate of Grx-1 through mass spectrometry. Recombinant Hsc70 was glutathionylated in …

A Striking New Species Of The Eleutherodactylus From Andean Peru (Anura: Leptodactylidae), Edgar Lehr, Cesar Aguilar, William Duellman

Edgar Lehr

No abstract provided.

Growth Rate Gradients And Extracellular Ph In Roots: How To Control An Explosion, Winfried S. Peters

Winfried S. Peters

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

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 …

The C. Elegans Heterochronic Gene Lin-46 Affects Developmental Timing At Two Larval Stages And Encodes A Relative Of The Scaffolding Protein Gephyrin., Anita Pepper, Jill Mccane, Kevin Kemper, Denise Yeung, Rosalind Lee, Victor Ambros, Eric Moss

Victor R. Ambros

The succession of developmental events in the C. elegans larva is governed by the heterochronic genes. When mutated, these genes cause either precocious or retarded developmental phenotypes, in which stage-specific patterns of cell division and differentiation are either skipped or reiterated, respectively. We identified a new heterochronic gene, lin-46, from mutations that suppress the precocious phenotypes caused by mutations in the heterochronic genes lin-14 and lin-28. lin-46 mutants on their own display retarded phenotypes in which cell division patterns are reiterated and differentiation is prevented in certain cell lineages. Our analysis indicates that lin-46 acts at a step immediately downstream …