The Effects of Diet and Cooler Aging on Specific Flavor Notes in Beef

Crossbred steers (n = 64) were grazed on warm- or cool-season grass-dominated pastures, without or with energy supplementation of wet distillers grains with solubles (WDGS), and were finished on a corn-based diet with or without 35% WDGS. Finishing on corn increased desirable flavor notes and decreasedundesirable flavor notes in both L. dorsi and B. femoris steaks. In addition, grazing on warm-season grasses increased the prevalence of undesirable flavors but was often dissipated by the addition WDGS supplementation. Longer aging periods tended to increase the prevalence of undesirable flavors, especially in B. femoris steaks. It is recommended producers provide WDGS supplementation, especially when grazing on warm-season grasses, and finish on an all corn diet in order to create a favorable flavor palate

Characterization and comparison of lesions on ornamental sweetpotato 'Blackie', tomato 'Maxifort', interspecific geranium 'Caliente Coral', and bat-faced cuphea 'Tiny Mice'.

Many plant species are prone to physiological disorders in which lesions develop on the leaf tissue. Nomenclature for such lesions has included intumescences, excrescences, neoplasms, galls, genetic tumors, enations, and oedemata. Interchangeably using these terms causes confusion as to whether these names refer to the same or different disorders. Two of the most commonly used names are oedema and intumescence. The objective of this research was to characterize the development of lesions on ornamental sweetpotato (Ipomoea batatas ‘Blackie’), tomato (Solanum lycopersicum ‘Maxifort’), interspecific hybrid geranium(Pelargonium· ‘CalienteCoral’), and bat-faced cuphea (Cuphea llavea ‘TinyMice’) to determine similarities and differences in morphology and nomenclature among these physiological disorders. Light microscopy was used to characterize differences in cross-sectional height, width, and area of lesions on each species. Additionally, leaf tissue samples were embedded in paraffin, and 10-mm cross-sections were stained with Toluidine blue O and observed using light microscopy to identify specific cell layers involved with lesion development. Field emission scanning electron microscopy (SEM) and digital photography were used to observe the microscopic and macroscopic stages of lesion development, respectively, on each species. The lesions observed on ornamental sweetpotato were significantly greater in height and area than on the other three species, whereas tomato lesions were significantly greater in width. Lesions on ornamental sweetpotato and bat-faced cuphea occurred predominantly on the adaxial surface of the leaf, whereas lesions on geraniumand tomato occurred predominantly on the abaxial surface.With lesions on tomato, ornamental sweetpotato, and bat-faced cuphea, the epidermis was often subjected to the same hypertrophy apparent in the underlying parenchyma cells, ultimately allowing for greater cell expansion. However, in geranium, the epidermis resisted the expansion of the underlying cells, resulting in the eventual tearing of this tissue layer. Previous research indicates that lesion development on geranium is closely related to water status within the plant and may result in a wound response or provide a means of facilitated gas exchange. On the contrary, development of lesions on ornamental sweetpotato and tomato is believed to involve light quality. Based on these results and observations, two disorders occur across these species. The term "intumescence’’ should be used when referring to abnormal lesions on ornamental sweetpotato and tomato, and the term ‘‘oedema’’ should be used when referring to lesions on geranium. The term ‘‘intumescence’’ should also be used when referring to bat-faced cuphea lesions resulting from the morphological and anatomical aspects of these lesions closely resembling development on ornamental sweetpotato and tomato. Future research should investigate the role of light quality regarding development on this species

Human Pluripotent Stem Cells Serve as an Effective In Vitro Model for Studies of Early Stages of Retinogenesis

poster abstractSpecification of the neural retina is one of the first events in human development and thus, efforts to study the initial stages of retinal specification have been largely limited. This is particularly true for the earliest event in retinogenesis, the establishment of a definitive retinal fate from a more primitive neural progenitor source. With the advent of human pluripotent stem cells (hPSCs), the complex interplay of transcription factors involved in early events of retinal development from an unspecified pluripotent population can be studied in an in vitro model. To examine this potential, hPSCs were directed to differentiate to a neuroretinal lineage in which a subpopulation of cells adopts a definitive retinal fate whereas others develop toward a forebrain lineage. Samples were collected over the first month of differentiation, starting from the undifferentiated state through when cells acquired either retinal or nonretinal forebrain identities and gene expression patterns were characterized using immunocytochemistry and quantitative RT-PCR. Results demonstrated that while neural transcription factors such as PAX6, OTX2, and LHX2 were expressed early in development, definite retinal transcription factors such as CHX10 were expressed later in differentiation. Furthermore, the expression of CHX10 was found to be uniquely associated with retinal populations and remained absent from the other neural populations, thereby illustrating the ability of this protocol to uniquely identify and isolate retinal populations and further study them in vitro. Overall, these studies will serve to further understand the specification of a retinal fate from a pluripotent population. Such information will assist in the establishment of more efficient methods to generate retinal cells from hiPSCs for translational purposes, as well as establish hiPSCs as a unique in vitro model system for studies of the earliest stages of human development. Mentor: Jason S. Meyer1-

The YsrS Paralog DygS Has the Capacity To Activate Expression of the Yersinia enterocolitica Ysa Type III Secretion System

ABSTRACT The Yersinia enterocolitica Ysa type III secretion system (T3SS) is associated with intracellular survival, and, like other characterized T3SSs, it is tightly controlled. Expression of the ysa genes is only detected following growth at low temperatures (26°C) and in high concentrations of sodium chloride (290 mM) in the medium. The YsrSTR phosphorelay (PR) system is required for ysa expression and likely responds to NaCl. During our investigations into the Ysr PR system, we discovered that genes YE3578 and YE3579 are remarkably similar to ysrR and ysrS , respectively, and are probably a consequence of a gene duplication event. The amino acid differences between YE3578 and ysrR are primarily clustered into two short regions. The differences between YE3579 and ysrS are nearly all located in the periplasmic sensing domain; the cytoplasmic domains are 98% identical. We investigated whether these paralogs were capable of activating ysa gene expression. We found that the sensor paralog, named DygS, is capable of compensating for loss of ysrS , but the response regulator paralog, DygR, cannot complement a ysrR gene deletion. In addition, YsrR, but not DygR, interacts with the histidine phosphorelay protein YsrT. Thus, DygS likely activates ysa gene expression in response to a signal other than NaCl and provides an example of a phosphorelay system in which two sensor kinases feed into the same regulatory pathway. IMPORTANCE All organisms need mechanisms to promote survival in changing environments. Prokaryotic phosphorelay systems are minimally comprised of a histidine kinase (HK) that senses an extracellular stimulus and a response regulator (RR) but can contain three or more proteins. Through gene duplication, a unique hybrid HK was created. We show that, while the hybrid appears to retain all of the phosphorelay functions, it responds to a different signal than the original. Both HKs transmit the signal to the same RR, which activates a promoter that transcribes a set of genes encoding a type III secretion system (T3SS) whose function is not yet evident. The significance of this work lies in finding that two HKs regulate this T3SS, highlighting its importance

Increasing Teachers\u27 Metacognition Develops Students\u27 Higher Learning during Content Area Literacy Instruction: Findings from the Read-Write Cycle Project

Success in the 21st century, for individuals and societies, requires competence in comprehending and communicating in the academic disciplines--the natural sciences, history, geography, and more. The Read-Write Cycle (RWC) Project, a three year longitudinal research study conducted from 2005-2008 in ten public elementary schools in southern California, explored the effectiveness of curriculum and instructional strategies that integrate literacy with disciplinary knowledge with the simultaneous goals of: (1) enhancing students\u27 literacy outcomes; and (2) broadening and deepening knowledge of the content area. Funded by the U.S. Institute of Education Sciences, the RWC Project concentrated over years one and two on 1,024 students in grades three through six and the ongoing professional development of 18 classroom teachers. This documentary account focuses on one aspect of the larger project, specifically the RWC Project\u27s effect on teachers\u27 metacognition about their own practice leading to upper elementary grade students\u27 higher learning by developing students\u27: (1) metacognition and reflection; (2) exploration and depth in content domains; and (3) integration of literacy in content areas

A Serendipitous Mutation Reveals the Severe Virulence Defect of a Klebsiella pneumoniae fepB Mutant

ABSTRACT Klebsiella pneumoniae is considered a significant public health threat because of the emergence of multidrug-resistant strains and the challenge associated with treating life-threatening infections. Capsule, siderophores, and adhesins have been implicated as virulence determinants of K. pneumoniae , yet we lack a clear understanding of how this pathogen causes disease. In a previous screen for virulence genes, we identified a potential new virulence locus and constructed a mutant ( smr ) with this locus deleted. In this study, we characterize the smr mutant and show that this mutation renders K. pneumoniae avirulent in a pneumonia model of infection. The smr mutant was expected to have a deletion of three genes, but subsequent genome sequencing indicated that a much larger deletion had occurred. Further analysis of the deleted region indicated that the virulence defect of the smr mutant could be attributed to the loss of FepB, a periplasmic protein required for import of the siderophore enterobactin. Interestingly, a Δ fepB mutant was more attenuated than a mutant unable to synthesize enterobactin, suggesting that additional processes are affected. As FepB is highly conserved among the members of the family Enterobacteriaceae , therapeutic targeting of FepB may be useful for the treatment of Klebsiella and other bacterial infections. IMPORTANCE In addition to having a reputation as the causative agent of several types of hospital-acquired infections, Klebsiella pneumoniae has gained widespread attention as a pathogen with a propensity for acquiring antibiotic resistance. It is capable of causing a range of infections, including urinary tract infections, pneumonia, and sepsis. Because of the rapid emergence of carbapenem resistance among Klebsiella strains, there is a dire need for a better understanding of virulence mechanisms and identification of new drug targets. Here, we identify the periplasmic transporter FepB as one such potential target

Nicarbazin OvoControl G Bait Reduces Hatchability of Eggs Laid by Resident Canada Geese in Oregon

Expanding populations of resident Canada geese (Branta canadensis) are resulting in increased conflicts with humans. Nonlethal and humane means are needed for managing Canada goose flocks at a variety of sites, including golf courses, industrial parks, government sites, and city parks. Decreased egg production and hatching are side effects of nicarbazin, a veterinary drug used to treat coccidiosis in chickens. Capitalizing on these effects, we developed nicarbazin as a reproductive inhibitor for Canada geese and conducted a field efficacy study. We recruited study sites in 2002 and 2003. Following laboratory testing, we conducted a field efficacy trial of nicarbazin for reducing the hatchability of Canada goose eggs in spring 2004 in Oregon, USA. The study began in February 2004 at 10 sites in Oregon, with 2 control and 3 treated sites on each side of the Cascades. We fed bait daily to resident Canada geese for approximately 6 weeks. We located and monitored nests until hatching or ≥5 days beyond the expected hatching date to determine hatchability. We completed data collection in May 2004. Geese consumed 8,000 kg of bait, with 5,100 kg of OvoControl G* (Innolytics, LLC, Rancho Santa Fe, CA) 2,500-ppm nicarbazin bait consumed among 6 treated sites and 2,900 kg of untreated bait consumed among 4 control sites. We monitored 63 nests at treated sites and 46 nests at control sites to determine hatching success of eggs. There was a 62% reduction in the percentage of nests with 100% hatchability at treated sites as compared to controls. There was a 93% increase in the percentage of nests at treated sites with 0% hatchability as compared to nests with no eggs hatching at control sites. Hatchability from treated sites versus control sites was reduced 36%(F=5.72, P=0.0622). We submitted results from this study to support Environmental Protection Agency registration of nicarbazin as a reproductive inhibitor for use in Canada geese. We have shown that treatment of resident Canada geese with OvoControl G 2,500-ppm nicarbazin bait by licensed, trained applicators immediately prior to and during the breeding season can reduce hatchability of eggs laid by treated geese, thereby reducing recruitment of goslings into problem resident Canada goose populations. ( JOURNAL OF WILDLIFE MANAGEMENT 71(1):135–143; 2007

Phylogeography of the Endangered Otago Skink, Oligosoma otagense: Population Structure, Hybridisation and Genetic Diversity in Captive Populations

Climatic cooling and substantial tectonic activity since the late Miocene have had a pronounced influence on the evolutionary history of the fauna of New Zealand's South Island. However, many species have recently experienced dramatic range reductions due to habitat fragmentation and the introduction of mammalian predators and competitors. These anthropogenic impacts have been particularly severe in the tussock grasslands of the Otago region. The Otago skink (Oligosoma otagense), endemic to the region, is one of the most critically endangered vertebrates in New Zealand. We use mitochondrial DNA sequence data to investigate the evolutionary history of the Otago skink, examine its population genetic structure, and assess the level of genetic diversity in the individuals in the captive breeding program. Our data indicate that the Otago skink diverged from its closest relatives in the Miocene, consistent with the commencement of tectonic uplift of the Southern Alps. However, there is evidence for past introgression with the scree skink (O. waimatense) in the northern Otago-southern Canterbury region. The remnant populations in eastern Otago and western Otago are estimated to have diverged in the mid-Pliocene, with no haplotypes shared between these two regions. This divergence accounts for 95% of the genetic diversity in the species. Within both regions there is strong genetic structure among populations, although shared haplotypes are generally evident between adjacent localities. Although substantial genetic diversity is present in the captive population, all individuals originate from the eastern region and the majority had haplotypes that were not evident in the intensively managed populations at Macraes Flat. Our data indicate that eastern and western populations should continue to be regarded as separate management units. Knowledge of the genetic diversity of the breeding stock will act to inform the captive management of the Otago skink and contribute to a key recovery action for the species

Controlled cardiac reoxygenation does not improve myocardial function following global myocardial ischemia

AbstractBackgroundIt has been shown that abrupt re-exposure of ischemic myocardium to oxygen can lead to increased peroxidative damage to myocytes (oxygen paradox). Controlled cardiac reoxygenation, as an adjunct to substrate-enhanced cardioplegia, has been shown to improve myocardial function and limit reperfusion injury when utilizing standardized hyperoxic cardiopulmonary bypass (CPB). The objective of our study was to evaluate the effect of controlled reoxygenation on myocardial function following global ischemia employing normoxic CPB.Study designNineteen female swine (30–40kg) were placed on vented, normoxic CPB. They were subjected to 45–50min of unprotected global ischemia (aortic cross clamping) followed by 30min of controlled cardiac reperfusion utilizing substrate-enhanced cardioplegia. Group 1 maintained normoxic pO2 (O2 tension of 90–110mmHg). In Group 2, reoxygenation was titrated gradually and increased from venous to arterial levels (O2 tensions from 40 to 110mmHg over 15min). We measured coronary sinus blood samples for CK, CK-MB, nitric oxide, and conjugated dienes at baseline, 5min into the cardioplegic resuscitation, 5min after the cross clamp removal, and just prior to the termination of the study. Hearts were pathologically studied and scored for evidence of tissue peroxidation.ResultsAlthough not significantly different, Group 1 (normoxic reperfusion) animals were more likely to wean from CPB (p=0.141) and had a higher mean arterial pressure (p=0.556). In Group 1, conjugated dienes were significantly higher 5min into the resuscitative protocol (p=0.018) and at the termination of bypass (p=0.035). Five of six animals in Group 1 eventually attained normal sinus rhythm as opposed to three out of 13 in Group 2 (p=0.041). There was no significant difference in histology scoring between the two groups for tissue peroxidation.ConclusionThis study of controlled cardiac reoxygenation in a lethal ischemic swine model failed to demonstrate that the use of controlled reoxygenation on the myocardial function following global ischemia was better with maintained normoxic pO2 (with O2 tensions of 90–110mmHg) than when reoxygenation was titrated gradually and increased from venous to arterial levels (O2 tensions from 40 to 110mmHg over 15min)

Chlamydia Prevalence Trends among Women and Men Entering the National Job Training Program from 1990 Through 2012

Background Evaluating chlamydia prevalence trends from sentinel surveillance is important for understanding population disease burden over time. However, prevalence trend estimates from surveillance data may be misleading if they do not account for changes in risk profiles of individuals who are screened (case mix) and changing performance of the screening tests used. Methods We analyzed chlamydia screening data from a sentinel surveillance population of 389,555 young women (1990-2012) and 303,699 young men (2003-2012) entering the US National Job Training Program. This period follows the introduction of national chlamydia screening programs designed to prevent transmission and reduce population disease burden. After ruling out bias due to case mix, we used an expectation-maximization-based maximum likelihood approach to account for measurement error from changing screening tests, and generated minimally biased long-term chlamydia prevalence trend estimates among youth and young adults in this sentinel surveillance population. Results Adjusted chlamydia prevalence among women was high throughout the study period, but fell from 20% in 1990 to 12% in 2003, and remained between 12% and 14% through 2012. Adjusted prevalence among men was steady throughout the study period at approximately 7%. For both women and men, adjusted prevalence was highest among Black and American Indian youth and young adults, and in the Southern and Midwestern regions of the United States throughout the study period. Conclusions Our minimally biased trend estimates provide support for an initial decrease in chlamydia prevalence among women soon after the introduction of national chlamydia screening programs. Constant chlamydia prevalence in more recent years suggests that screening may not be sufficient to further reduce chlamydia prevalence among high-risk youth and young adults