An Investigation into Landing Approach Visual Illusions

This experiment was designed to examine aspects of human visual perception during approaches to a runway. The runway width illusion has commonly been reported to contribute to the dangerous tendency of pilots to fly low approaches to runways that are wide and high approaches to runways that are narrow. Attempts to prevent the runway width illusion have not attempted to identify the ideal location for an indicator of altitude. Thus the present experiment examined the effect of varying runway width and manipulated scenes in order to determine whether the runway width illusion was present and where participants were focusing their attention in the scenes. Thirty-two non-pilot participants and 3 pilots took part in the experiment and viewed static and dynamic scenes of runways that were narrow (30.48m), medium (60.96m) or wide (91.44m) at one of three viewing heights low (30.48m), medium (45.72m) or high (60.96m). After viewing scenes, participants were required to estimate their altitude and aim-point. The results of this experiment revealed that participants were fairly inaccurate at estimating altitude and were inclined to overestimate aim-point, however the data also indicated that there was a robust runway width illusion that was present across static and dynamic trials and in both altitude and aim-point data. The standard marking on the runway in an attempt to prevent the runway width illusion was not effective at preventing incorrect altitude estimations but did assist participants to estimate aim-point. It was also found that the objects that participants' most commonly reported using to estimate altitude in the visual scene were located in the lower segment of the scenes

Environmental factors affecting survival of Campylobacter jejuni in vacuum packaged processed turkey

The effect of nitrite upon growth and survival of Campylobacter jejuni, and the effect of vacuum packaged storage at 4°C upon survival of C. jejuni in processed turkey ham and turkey were evaluated. Minimum inhibitory concentrations (MIC) and minimum lethal concentrations (MLC) of sodium nitrite for C. jejuni were determined at pH 6.0 and 7.0 by a modified tube dilution method. The MIC and MLC at both pH levels ranged from 200-1100 ppm and were above the legal limit of sodium nitrite that could be added to meats. It was concluded that sodium nitrite alone at \u3c156 ppm would not inhibit growth and survival ofC. jejuni in cured meats having a pH greater than 6.0. To determine the effect of vacuum packaged storage on survival of C. jejuni, turkey ham and turkey roll samples were sliced, inoculated with C. jejuni, vacuum packaged, and stored at 4°C for 0, 1, 3, 7, 10, and 14 d. An additional set of samples were prepared for turkey ham to extend storage to 28 d. Three different strains of C. jejuni were evaluated. An inoculated sample for each strain and a control sample with no inoculum were prepared for each sample and each storage period. After appropriate incubation, the inoculated samples were analyzed for surviving C. jejuni. Control samples were analyzed for aerobic plate count. Survival of C. jejuni during vacuum packaged storage at 4°C decreased significantly over time (P\u3c0.05). A significant difference in viability existed between the three test strains used (P\u3c0.05). Survival of C. jejuni was better in the turkey ham than the turkey roll. Aerobic plate count increased significantly during storage (P\u3c0.05) providing atagonistic competition for C. jejuni survival. Though survival of C. jejuni decreased over time, viable cells were detected up to 28 d. Apparently, the effect of vacuum packaged storage at 4°C in turkey ham and turkey roll upon survival of Campylobacter jejuni was inhibitory, though not immediately lethal

Functional studies of vertebrate β-defensins

The β-defensins are a family of small, cationic antimicrobial peptides. They are conserved in a variety of species ranging from lower vertebrates to mammals and plants, and were first identified for their broad-spectrum antimicrobial activity. Since their initial discovery, this role has broadened to include a number of diverse additional functions including the chemotaxis of immune cells (immature dendritic cells, macrophages and CD4+ T cells), the determination of coat colour in dogs and seed maturation in tomatoes.The aim of this thesis is to investigate the function of vertebrate beta-defensins. 1 address this question by assessing how mouse β-defensin structure affects its bactericidal activity and also by carrying out P-defensin knockdown studies in zebrafish.In this work, 1 address the question of how β-defensin structure affects its bactericidal activity by examining the effects of sequentially removing amino acids from the N-terminal of murine Defbl4. I show that these deletions reduce bactericidal activity however the effects are much more striking in gram positive species than gram negative. Through the comparison of monomeric and dimeric species as well as analysis of peptide charge and hydrophobicity, this work indicates that a combination of primary sequence and structure is responsible for the bactericidal properties of this peptide.In addition, this thesis describes the characterisation of three β-defensin-like peptides (Defbll, Defbl2 and DefbB) previously described in zebrafish. 1 utilise antimicrobial assays to determine the bactericidal properties of synthetic Defbl2 and DefbB against a panel of microbes and also show that Defbll is antimicrobially inactive. Furthermore, this work identifies the expression of defbll during zebrafish gastrulation and utilises a combination of wholemount in situ hybridisation, morpholino knockdown and rescue and microarray analysis to ascertain a novel essential role for this peptide in early development.This work is the first report of a β-defensin being involved in vertebrate development and presents a further widening of the influence of the defensin family

Glucocorticoids are lower at delivery in maternal, but not cord blood of obese pregnancies

Abstract Glucocorticoids are vital for lung maturation. We previously showed that cortisol is lower in obese pregnancy. Whether this is maintained at delivery is unknown but is clinically relevant as maternal and cord blood cortisol levels are correlated and offspring of obese are more likely to need neonatal respiratory support. We hypothesized that glucocorticoids are lower in maternal and cord blood at delivery in obese pregnancies. Glucocorticoids (cortisol and corticosterone) and their inactive versions (cortisone and 11-dehydrocorticosterone) were measured by LC-MS/MS in maternal and cord plasma from 259 Caucasian women at delivery (BMI 18–55 kg/m2). Analyses adjusted for labour status, delivery mode, offspring gender, birthweight and gestational age. Cortisol and corticosterone were significantly higher in maternal than cord blood. Inactive versions were significantly higher in cord than maternal blood. Increased maternal BMI associated with lower maternal cortisol, corticosterone and 11-dehydrocorticosterone. Despite significant positive correlations between maternal and cord blood glucocorticoid levels, increased maternal BMI was not associated with lower cord blood glucocorticoid levels. Conditions at delivery may overcome any potential negative effects of low maternal glucocorticoids on the fetus in the short-term. This may not preclude the longer-term effects of fetal exposure to lower glucocorticoid levels during obese pregnancy

Influence of the Valine Zipper Region on the Structure and Aggregation of the Basic Leucine Zipper (bZIP) Domain of Activating Transcription Factor 5 (ATF5)

Protein aggregation is a major problem for biopharmaceuticals. While the control of aggregation is critically important for the future of protein pharmaceuticals, mechanisms of aggregate assembly, particularly the role that structure plays, are still poorly understood. Increasing evidence indicates that partially folded intermediates critically influence the aggregation pathway. We have previously reported the use of the basic leucine zipper (bZIP) domain of Activating Transcription Factor 5 (ATF5) as a partially folded model system to investigate protein aggregation. This domain contains three regions with differing structural propensity: a N-terminal polybasic region, a central helical leucine zipper region, and a C-terminal extended valine zipper region. Additionally, a centrally positioned cysteine residue readily forms an intermolecular disulfide bond that reduces aggregation. Computational analysis of ATF5 predicts that the valine zipper region facilitates self-association. Here we test this hypothesis using a truncated mutant lacking the C-terminal valine zipper region. We compare the structure and aggregation of this mutant to the wild-type (WT) form under both reducing and non-reducing conditions. Our data indicate that removal of this region results in a loss of alpha-helical structure in the leucine zipper and a change in the mechanism of self-association. The mutant form displays increased association at low temperature but improved resistance to thermally induced aggregation

Identifying aquaponics information gaps: An examination of educational resources available to home hobbyists in Minneapolis garden center sites

Aquaponics home hobbyists may rely on garden centers as an important source of materials and information. Our study evaluated garden center staff knowledge about aquaponics in order to help the staff close their own information and training gaps, and strengthen their exchanges with home hobbyists. Over time this will strengthen the aquaponics network of garden centers and home hobbyists and enhance the diffusion of aquaponics systems

The New Hysteria: Borderline Personality Disorder and Epistemic Injustice

The diagnostic category of borderline personality disorder (BPD) has come under increasing criticism in recent years. In this paper, we contribute to that literature by analyzing the role and impact of epistemic injustice, specifically testimonial injustice, in relation to the diagnosis of BPD. We first offer a critical sociological and historical account, detailing and expanding a range of arguments that BPD is problematic nosologically. We then turn to explore the epistemic injustices that can result from a BPD diagnosis, showing that the experiences of testimonial injustice within BPD prevent patient engagement in meaning-making activities, thereby undermining standard therapeutic goals. We conclude by showing how our arguments bolster ongoing efforts to replace the diagnostic category of BPD with alternatives such as complex post-traumatic stress disorder