AN ENTERPRISE COMPETITION ANALYSIS OF BEEF PRODUCTION IN THE SOUTH

Livestock Production/Industries,

A Laboratory Study of Buoyant Coarse Media Flocculation

In water treatment, flocculation is the unit operation in which destabilized particles are given the opportunities to collide with each other and aggregate into floc. Traditionally the mixing necessary for these collisions has been mechanically induced: mechanical mixers in the flocculation basins create velocity gradients in the water being flocculated and the conditions for the agglomeration of particles. However, the energy imparted to a water being flocculated does not necessarily have to come from mechanical mixing. Hydraulic flocculation is also widely used for the purpose of inducing velocity gradients. Hydraulic flocculation occurs when the turbulence in the water is not the result of mechanical action, but rather of the hydraulic design of the flocculator. The advantages of hydraulic flocculators are that there is less mechanical equipment and less maintenance than with mechanical flocculators, and performance is good at constant flow rates. The disadvantages of traditional hydraulic flocculators are a relatively high head loss and the difficulty of adjusting the system to changing flow rates. A pilot plant study of buoyant coarse media (BCM) flocculation was conducted at the University of North Carolina at Chapel Hill to determine the feasibility and possible applications of this process. BCM flocculation is a type of hydraulic flocculation in which passage of water through a bed of media provides the turbulence necessary for floe formation. As destabilized particles pass around the media, eddies in the pore spaces between the media create the turbulence needed for particle collisions and flocculation.Master of Science in Environmental Engineerin

A Diverse Group of Previously Unrecognized Human Rhinoviruses Are Common Causes of Respiratory Illnesses in Infants

Human rhinoviruses (HRVs) are the most prevalent human pathogens, and consist of 101 serotypes that are classified into groups A and B according to sequence variations. HRV infections cause a wide spectrum of clinical outcomes ranging from asymptomatic infection to severe lower respiratory symptoms. Defining the role of specific strains in various HRV illnesses has been difficult because traditional serology, which requires viral culture and neutralization tests using 101 serotype-specific antisera, is insensitive and laborious.To directly type HRVs in nasal secretions of infants with frequent respiratory illnesses, we developed a sensitive molecular typing assay based on phylogenetic comparisons of a 260-bp variable sequence in the 5' noncoding region with homologous sequences of the 101 known serotypes. Nasal samples from 26 infants were first tested with a multiplex PCR assay for respiratory viruses, and HRV was the most common virus found (108 of 181 samples). Typing was completed for 101 samples and 103 HRVs were identified. Surprisingly, 54 (52.4%) HRVs did not match any of the known serotypes and had 12-35% nucleotide divergence from the nearest reference HRVs. Of these novel viruses, 9 strains (17 HRVs) segregated from HRVA, HRVB and human enterovirus into a distinct genetic group ("C"). None of these new strains could be cultured in traditional cell lines.By molecular analysis, over 50% of HRV detected in sick infants were previously unrecognized strains, including 9 strains that may represent a new HRV group. These findings indicate that the number of HRV strains is considerably larger than the 101 serotypes identified with traditional diagnostic techniques, and provide evidence of a new HRV group

Comparative Genomic Characterization of Francisella tularensis Strains Belonging to Low and High Virulence Subspecies

Tularemia is a geographically widespread, severely debilitating, and occasionally lethal disease in humans. It is caused by infection by a gram-negative bacterium, Francisella tularensis. In order to better understand its potency as an etiological agent as well as its potential as a biological weapon, we have completed draft assemblies and report the first complete genomic characterization of five strains belonging to the following different Francisella subspecies (subsp.): the F. tularensis subsp. tularensis FSC033, F. tularensis subsp. holarctica FSC257 and FSC022, and F. tularensis subsp. novicida GA99-3548 and GA99-3549 strains. Here, we report the sequencing of these strains and comparative genomic analysis with recently available public Francisella sequences, including the rare F. tularensis subsp. mediasiatica FSC147 strain isolate from the Central Asian Region. We report evidence for the occurrence of large-scale rearrangement events in strains of the holarctica subspecies, supporting previous proposals that further phylogenetic subdivisions of the Type B clade are likely. We also find a significant enrichment of disrupted or absent ORFs proximal to predicted breakpoints in the FSC022 strain, including a genetic component of the Type I restriction-modification defense system. Many of the pseudogenes identified are also disrupted in the closely related rarely human pathogenic F. tularensis subsp. mediasiatica FSC147 strain, including modulator of drug activity B (mdaB) (FTT0961), which encodes a known NADPH quinone reductase involved in oxidative stress resistance. We have also identified genes exhibiting sequence similarity to effectors of the Type III (T3SS) and components of the Type IV secretion systems (T4SS). One of the genes, msrA2 (FTT1797c), is disrupted in F. tularensis subsp. mediasiatica and has recently been shown to mediate bacterial pathogen survival in host organisms. Our findings suggest that in addition to the duplication of the Francisella Pathogenicity Island, and acquisition of individual loci, adaptation by gene loss in the more recently emerged tularensis, holarctica, and mediasiatica subspecies occurred and was distinct from evolutionary events that differentiated these subspecies, and the novicida subspecies, from a common ancestor. Our findings are applicable to future studies focused on variations in Francisella subspecies pathogenesis, and of broader interest to studies of genomic pathoadaptation in bacteria

Grain-Fed Versus Grass-Fed Beef Production

The poor 1974 U.S. corn crop caused sharp rises in feed prices and many changes were made in beef production. Large numbers of cattle were forced to slaughter because of short feed supplies and nongrain-fed beef slaughter increased. World food shortages prompted much discussion about beef production being a wasteful use of food producing resources. Quantities of grain consumed by beef cattle per pound of beef produced are, however, less than that assumed by many