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Full-Text Articles in Life Sciences

Effectiveness Of A Novel Spontaneous Carvacrol Nanoemulsion Against Salmonella Enterica Enteritidis And Escherichia Coli O157:H7 On Contaminated Mung Bean And Alfalfa Seeds, Kyle Landry, Yuhua Chang, David Julian Mcclements, Lynne Mclandsborough Sep 2014

Effectiveness Of A Novel Spontaneous Carvacrol Nanoemulsion Against Salmonella Enterica Enteritidis And Escherichia Coli O157:H7 On Contaminated Mung Bean And Alfalfa Seeds, Kyle Landry, Yuhua Chang, David Julian Mcclements, Lynne Mclandsborough

Kyle S Landry

Outbreaks of foodborne illness from consumption of sprouts have been linked to contaminated seeds prior to germination. Due to the long sprouting period at ambient temperatures and high humidity, germinating seeds contaminated with low pathogen levels (0.1 log CFU/g) can result in sprouts with high numbers (≥ 108 CFU/g) of pathogens. Currently, the recommended treatment method involves soaking seeds in 20,000 ppm (2%) calcium hypochlorite prior to germination. In this study, an alternative treatment involving soaking seeds in a carvacrol nanoemulsion was tested for its efficacy against Salmonella enterica subspecies enterica serovar Enteritidis (ATCC BAA-1045) or EGFP expressing E. coli O157:H7 (ATCC 42895) …


Pubertal And Adult Leydig Cell Function In Mullerian Inhibiting Substance-Deficient Mice, Xiufeng Wu, Ramamani Arumugam, Stephen Baker, Mary Lee Sep 2014

Pubertal And Adult Leydig Cell Function In Mullerian Inhibiting Substance-Deficient Mice, Xiufeng Wu, Ramamani Arumugam, Stephen Baker, Mary Lee

Mary M. Lee

Mullerian inhibiting substance (MIS) causes Mullerian duct regression during sexual differentiation and regulates postnatal Leydig cell development. MIS knockout (MIS-KO) mice with targeted deletions of MIS develop Leydig cell hyperplasia, but their circulating androgen concentrations are reportedly unaltered. We compared reproductive hormone profiles, androgen biosynthesis, and the expression of key steroidogenic and metabolic enzymes in MIS-KO and wild-type (WT) mice at puberty (36 d) and sexual maturity (60 d). In pubertal animals, basal testosterone and LH concentrations in plasma were lower in MIS-KO than WT mice, whereas human chorionic gonadotropin-stimulated testosterone concentrations were similar. In adults, basal LH, and both …


Characterization Of A Recently Purified Thermophilic Dnase From A Novel Thermophilic Fungus, Kyle Landry, Robert Levin Jul 2014

Characterization Of A Recently Purified Thermophilic Dnase From A Novel Thermophilic Fungus, Kyle Landry, Robert Levin

Kyle S Landry

A newly isolated thermophilic fungus was found to produce a partially inducible extracellular DNase. This manuscript focuses on the characterization of this novel thermophilic DNase in terms of optimal enzyme conditions, molecular weight, and certain kinetic properties. The DNase was found to be inactivated by the presence of EDTA demonstrating its dependence on metal cofactors for activity. Maximum activity occurred at pH 6.0 with no activity at pH 2.0 or 10.0. The optimal temperature for the purified DNase was 65 °C. The thermophilic DNase was found to be an exonuclease with an estimated molecular weight of 56 kDa.


The Orientation Of Strophomenid Brachiopods On Soft Substrates, Roy Plotnick, Benjamin Dattilo, Daniel Piquard, Jennifer Bauer, Joshua Corrie Jul 2014

The Orientation Of Strophomenid Brachiopods On Soft Substrates, Roy Plotnick, Benjamin Dattilo, Daniel Piquard, Jennifer Bauer, Joshua Corrie

Benjamin F. Dattilo

Strophomenid brachiopods have long been interpreted as ‘‘snowshoe’’ strategists, with their flattened concavoconvex valves providing resistance to foundering in very soft sediments. There has been a sharp difference of opinion in whether the shells were oriented with their convex or their concave surface in contact with the sediment. This study, along with independent evidence from sedimentology, ichnology, and morphology, indicates that the strophomenids lived with their shells concave down (convex up). Experiments indicate the force required to push shells into soft cohesive muds is much greater for the convex up than for the convex down orientation. Forces also increase with …


Crystal Structure And Functional Assignment Of Yfau, A Metal Ion Dependent Class Ii Aldolase From Escherichia Coli K12, Dean Rea, Rebecca Hovington, John Rakus, John Gerlt, Vilmos Fu¨Lo¨P, Timothy Bugg, David Roper Jun 2014

Crystal Structure And Functional Assignment Of Yfau, A Metal Ion Dependent Class Ii Aldolase From Escherichia Coli K12, Dean Rea, Rebecca Hovington, John Rakus, John Gerlt, Vilmos Fu¨Lo¨P, Timothy Bugg, David Roper

John F. Rakus

One of the major challenges in the postgenomic era is the functional assignment of proteins using sequence- and structure-based predictive methods coupled with experimental validation. We have used these approaches to investigate the structure and function of theEscherichia coli K-12 protein YfaU, annotated as a putative 4-hydroxy-2-ketoheptane-1,7-dioate aldolase (HpcH) in the sequence databases. HpcH is the final enzyme in the degradation pathway of the aromatic compound homoprotocatechuate. We have determined the crystal structure of apo-YfaU and the Mg2+−pyruvate product complex. Despite greater sequence and structural similarity to HpcH, genomic context suggests YfaU is instead a 2-keto-3-deoxy sugar aldolase like the …


Stratigraphic Distribution And Suggested Evolution Of Dendroid Graptolites From The Silurian Of Eastern Australia, Barrie Rickards, Anthony Wright Apr 2014

Stratigraphic Distribution And Suggested Evolution Of Dendroid Graptolites From The Silurian Of Eastern Australia, Barrie Rickards, Anthony Wright

Anthony Wright

Five evolutionary lineages are proposed for Silurian species of the benthic dendroid graptolite genus Dictyonema, based largely on the exceptional eastern Australian records of the genus, comprising at least 25 species. These are: A, the delicatulum lineage with bifurcating ventral autothecal apertural spines; B, the paululum lineage with single ventral apertural spines or processes; C, the elegans lineage with isolated thecal apertures ± processes; D, the sherrardae lineage with dorsal apertural processes; and E, the venustum lineage with simple autothecal apertures. Brief comments are also made on other dendroid genera occurring in Australian strata, namely: Acanthograptus, Koremagraptus, Callograptus, Dendrograptus, Stelechocladia, …


Development Of A Novel Affinity Membrane Purification System For Deoxyribonuclease, Kyle Landry, Robert Levin Jan 2014

Development Of A Novel Affinity Membrane Purification System For Deoxyribonuclease, Kyle Landry, Robert Levin

Kyle S Landry

A membrane based affinity purification system was developed for the purification of the DNA specific nuclease, DNase I. Single stranded DNA was bound to unmodified polyvinylidene fluoride (PVDF) membranes which were used to purify DNase I from a solution of bovine serum albumin. Using coated membranes, a 6-fold increase in specific activity was achieved with 80 % enzyme recovery. This method provides a simple yet effective way to purify DNase I and can be very useful for the purification of other DNA specific enzymes.


The Evolution Of Billfish, Andrew Blitman Dec 2013

The Evolution Of Billfish, Andrew Blitman

Andrew Blitman

No abstract provided.


Insights Into The Cation Permeation Pathway Of Channelrhodopsin-2, Robert Dempski, Ryan Richards Dec 2013

Insights Into The Cation Permeation Pathway Of Channelrhodopsin-2, Robert Dempski, Ryan Richards

Robert E. Dempski

Channelrhodopsin-2 (ChR2) is a light-activated, non-selective cation channel endogenous to the green algae Chlamydomonas reinhardtii. The unique properties of ChR2 have made it a useful tool in the field of optogenetics. However, the mechanism of ion conductance is not well resolved. Elucidation of the crystal structure of the channelrhodopsin chimera C1C2 has provided structural insight on the putative ChR2 ion conductance pathway. However, it is not clear how the chimeric structure correlates to ChR2 function.


Purification Of An Inducible Dnase From A Thermophilic Fungus, Kyle Landry, Andrea Vu, Robert Levin Dec 2013

Purification Of An Inducible Dnase From A Thermophilic Fungus, Kyle Landry, Andrea Vu, Robert Levin

Kyle S Landry

The ability to induce an extracellular DNase from a novel thermophilic fungus was studied and the DNAse purified using both traditional and innovative purification techniques. The isolate produced sterile hyphae under all attempted growing conditions, with an average diameter of 2 μm and was found to have an optimal temperature of 45 °C and a maximum of 65 °C. Sequencing of the internal transcribed region resulted in a 91% match with Chaetomium sp., suggesting a new species, but further clarification on this point is needed. The optimal temperature for DNase production was found to be 55 °C and was induced by the …


Purification And Characterization Of Iso-Ribonucleases From A Novel Thermophilic Fungus, Kyle Landry, Robert Levin Dec 2013

Purification And Characterization Of Iso-Ribonucleases From A Novel Thermophilic Fungus, Kyle Landry, Robert Levin

Kyle S Landry

A thermophilic fungus previously isolated from composted horse manure was found to produce extracellular iso-RNases that were purified 127.6-fold using a combination of size exclusion chromatography and a novel affinity membrane purification system. The extent of purification was determined electrophoretically using 4%–15% gradient polyacrylamide gels. RNase activity was dependent on the presence of a metal co-factor with significantly more activity with Zn2+ or Mn2+ than Mg2+. The RNases exhibited maximum activity at both pH 3.0 and pH 7.0 with no activity at pH 2.0 or 10.0. The optimal temperature for the iso-RNase was 70 °C. The …