Growth of Streptococcus bovis and a Butyrivibrio in batch and continuous culture and the relationship of molar growth yield to intermicrobial competition : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Microbiology.

Cell growth yield of Streptococcus bovis and Butyrivibrio were determined in batch cultures where growth was separately limited by glucose, CO2 and trypticase. With bovis, glucose limited growth and a Yg of 39.6 g / M in the presence of excess CO2 was determined. S. bovis grew in the absence of CO2 , but the Yg was reduced to 16.5 g / M. In the presence of excess CO2 the Yg determined for Butyrivibrio was 55 g / M. Butyrivibrio was strictly limited by CO2 and the YCO2 was equal to Yg. This led to the suggestion that CO2 metabolism allows the generation of at least two additional ATP when combined with glucose metabolism for both organisms. Monod growth constants were determined for both organisms in continuous culture under glucose limitation. Ks and μmax for S. bovis were 0.429 mM / 1 and 2.47 hr-1 , respectively. For Butyrivibrio, Ks and μmax were 0.332 mM / 1 and 0.704 hr-1 , respectively. The cell growth yields for S. bovis and Butyrivibrio were determined to be 39.6 g / M and 69.1 g / M, respectively. At growth rates less than 0.2 hr-1 colony forming units and total cell counts of S. bovis decreased, but cell yield did not. Colony forming units, total counts and cell growth yield of Butyrivibrio did not decrease at low growth rates. When S. bovis and Butyrivibrio were grown in continuous mixed culture, Butyrivibrio dominated at growth rates below 0.5 hr-1 and growth of S. bovis was strongly depressed. That Butyrivibrio dominated mixed cultures supports the proposition that an organism deriving more ATP per mole of substrate that another will dominate in environments comparable with continuous culture. The roles of maintenance energy, Ks and μmax and cell yield in competition are considered

Do fundamental fears differentially contribute to pain-related fear and pain catastrophizing? An evaluation of the sensitivity index

Three fundamental fears - anxiety sensitivity (AS), injury/illness sensitivity (IS) and fear of negative evaluation (FNE) - have been proposed to underlie common fears and psychopathological conditions. In pain research, the relation between AS and (chronic) pain processes was the subject of several studies, whereas the possible role of IS has been ignored. The current research examines the role of IS with respect to various pain-related variables in two studies. In the first study, 192 healthy college students completed the Sensitivity Index (SI; a composite measure assessing the three fundamental fears) and various pain-related questionnaires. In a second study, 60 students out of the original sample took part in a pain induction procedure and completed the SI as well. We first examined the properties of the SI. Factor analysis on the SI replicated the proposed factor structure [Taylor S. The structure of fundamental fears, J Behav Ther Exp, Psychiat 1993;24:289-99]. However, some items of the ASI did show problematic loadings and were therefore excluded in subsequent analyses. The main hypothesis of the current study states that IS is a stronger predictor than AS of pain catastrophizing and fear of pain as assessed by self-report measures, and of pain tolerance and anticipatory fear of pain as assessed in a pain induction study. This hypothesis could be confirmed for all variables, except for pain tolerance, which was not predicted by any of the three fundamental fears. The current study can be considered as an impetus for devoting attention to IS in future pain research

Pain-related anxiety influences pain perception differently in men and women: A quantitative sensory test across thermal pain modalities

The sexes differ with respect to perception of experimental pain. Anxiety influences pain perception more in men than in women; however, there lacks research exploring which anxiety constructs influence pain perception differentially between men and women. Furthermore, research examining whether depression is associated with pain perception differently between the sexes remains scant. The present investigation was designed to examine how trait anxiety, pain-related anxiety constructs (ie, fear of pain, pain-related anxiety, anxiety sensitivity), and depression are associated with pain perception between the sexes. A total of 95 nonclinical participants (55% women) completed measures assessing the constructs of interest and participated in quantitative sensory testing using heat and cold stimuli administered by a Medoc Pathway Pain and Sensory Evaluation System. The findings suggest that pain-related anxiety constructs, but not trait anxiety, are associated with pain perception. Furthermore, these constructs are associated with pain intensity ratings in men and pain tolerance levels in women. This contrasts with previous research suggesting that anxiety influences pain perception mostly or uniquely in men. Depression was not systematically associated with pain perception in either sex. Systematic relationships were not identified that allow conclusions regarding how fear of pain, pain-related anxiety, and anxiety sensitivity may contribute to pain perception differentially in men and women; however, anxiety sensitivity was associated with increased pain tolerance, a novel finding needing further examination. The results provide directions for future research and clinical endeavors and support that fear and anxiety are important features associated with hyperalgesia in both men and women.MAT was supported by a Canadian Institutes of Health research doctoral award (FRN 113434). The current research was also made possible by a Canadian Institutes of Health Research master’s award granted to PGW (FRN 89120) and by a Canadian Institutes of Health Research operating grant held by GJGA (FRN 86658)

Exploring Item Order in Anxiety-Related Constructs: Practical Impacts of Serial Position

The present study was designed to test for item order effects by measuring four distinct constructs that contribute substantively to anxiety-related psychopathology (i.e., anxiety sensitivity, fear of negative evaluation, injury/illness sensitivity, and intolerance of uncertainty). Participants (n = 999; 71% women) were randomly assigned to complete measures for each construct presented in one of two modalities: (a) items presented cohesively as measures or (b) items presented randomly interspersed with one another. The results suggested that item order had a relatively small impact on item endorsement, response patterns, and reliabilities. The small impact was such that item order appears unlikely to influence clinical decisions related to these measures. These findings not only have implications for these and other similar measures, but further inform a long-standing debate about whether item grouping is a substantial concern in measurement. Accessed 6,950 times on https://pareonline.net from April 21, 2012 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Miedo a caer. El taijiquan como forma de terapia de exposición gradual en vivo

Las caídas en las personas mayores pueden causar lesiones que llevan a una pérdida de independencia. La pérdida de control postural, de equilibrio, y los menores tiempos de reacción son factores importantes favorecedores de las caídas (Lajoie & Gallagher, 2004). Los programas de ejercicio tradicionales se centran en el estudio y tratamiento de estos factores (Tideiksaar, 1997); sin embargo, el miedo a la caída –otro fuerte elemento factor favorecedor– ha recibido una relativamente escasa atención en la literatura terapéutica (Maki et al., 1991). Existen indicadores de que existe una relación directa entre el miedo a caer y las caídas (Myers et al., 1996), así como una relación entre la evitación de actividades por miedo y las caídas (Delbaere et al., 2004). El taijiquan, una antigua arte marcial china convertida en método de ejercitación (Wolf et al., 2001), se ha mostrado como una práctica efectiva para mejorar el miedo a las caídas y a los antecedentes previos de caídas (Tsang et al., 2004). Como las terapias de exposición gradual, los practicantes de taijiquan logran lenta y progresivamente, en un entorno de calma, posiciones cada vez más difíciles que simulan situaciones potencialmente generadoras de miedo. En comparación con otros tratamientos mediante el ejercicio, tales como el entrenamiento del equilibrio computerizado, la educación y el ejercicio gradual, el taijiquan ha dado como resultado reducciones significativas del miedo a caer y de las caídas en sí mismas (McGibbon et al., 2005). En este trabajo se revisan las investigaciones existentes sobre el taijiquan y las caídas, defendiéndolo como una forma de terapia de exposición gradual para reducir el miedo a las caídas y las caídas en personas mayores. También se discutirán las consecuencias de estos trabajos y las futuras líneas de investigación

Does parental anxiety cause biases in the processing of child-relevant threat material?

OBJECTIVES: Anxiety leads to biases in processing personally relevant information. This study set out to examine whether anxious parents also experience biases in processing child-relevant material. DESIGN AND METHODS: Ninety parents acted as a control condition, or received a social anxiety or child-related anxiety induction. They completed a task examining attentional biases in relation to child-threat words and social-threat words, and a task examining ability to categorize emotion in children's faces and voices. RESULTS: There was a trend indicating group differences in attentional bias towards social-threat words, and this appears to have been only in the social anxiety condition, but not the child anxiety or control conditions. For child-threat words, attentional bias was present in the child anxiety condition, but not the social anxiety or control conditions. In the emotion recognition task, there was no difference between the control and child anxiety conditions, but the social anxiety condition were more likely to erroneously label children's faces and voices as sad. CONCLUSIONS: Parents' anxious biases may spill over into their child's world. PRACTITIONER POINTS: Parents' anxious biases may spill over into their child's world. Anxious parents may have attentional biases towards threats in their children's environment. Anxious parents may over-attribute negative emotion to children

PTSD and the Experience of Pain: Research and Clinical Implications of Shared Vulnerability and Mutual Maintenance Models

It is common for individuals with symptoms of posttraumatic stress disorder (PTSD) to present with cooccurring pain problems, and vice versa. However, the relation between these conditions often goes unrecognized in clinical settings. In this paper, we describe potential relations between PTSD and chronic pain and their implications for assessment and treatment. To accomplish this, we discuss phenomenological similarities of these conditions, the prevalence of chronic pain in patients with PTSD, and the prevalence of PTSD in patients with chronic pain. We also present several possible explanations for the co-occurrence of these disorders, based primarily on the notions of shared vulnerability and mutual maintenance. The paper concludes with an overview of future research directions, as well as practical recommendations for assessing and treating patients who present with co-occurring PTSD or chronic pain symptoms.During the writing of this paper, Dr Asmundson was supported by a Canadian Institutes of Health Research operating grant, and Dr Katz was supported by a Canada Research Chair

Neuroanatomical substrates for the volitional regulation of heart rate

The control of physiological arousal can assist in the regulation of emotional state. A subset cortical and subcortical brain regions are implicated in autonomic control of bodily arousal during emotional behaviors. Here, we combined human functional neuroimaging with autonomic monitoring to identify neural mechanisms that support the volitional regulation of heart rate, a process that may be assisted by visual feedback. During functional magnetic resonance imaging (fMRI), 15 healthy adults performed an experimental task in which they were prompted voluntarily to increase or decrease cardiovascular arousal (heart rate) during true, false, or absent visual feedback. Participants achieved appropriate changes in heart rate, without significant modulation of respiratory rate, and were overall not influenced by the presence of visual feedback. Increased activity in right amygdala, striatum and brainstem occurred when participants attempted to increase heart rate. In contrast, activation of ventrolateral prefrontal and parietal cortices occurred when attempting to decrease heart rate. Biofeedback enhanced activity within occipito-temporal cortices, but there was no significant interaction with task conditions. Activity in regions including pregenual anterior cingulate and ventral striatum reflected the magnitude of successful task performance, which was negatively related to subclinical anxiety symptoms. Measured changes in respiration correlated with posterior insula activation and heart rate, at a more lenient threshold, change correlated with insula, caudate, and midbrain activity. Our findings highlight a set of brain regions, notably ventrolateral prefrontal cortex, supporting volitional control of cardiovascular arousal. These data are relevant to understanding neural substrates supporting interaction between intentional and interoceptive states related to anxiety, with implications for biofeedback interventions, e.g., real-time fMRI, that target emotional regulation

Korean Anxiety Sensitivity Index-3: Its Factor Structure, Reliability, and Validity in Non-Clinical Samples

ObjectiveaaThe aim here is to examine the factorial structure, internal consistency, and concurrent validity of the Korean version of the Anxiety Sensitivity Index-3 (K-ASI-3) in student samples in Korea. Also, we investigated the cross-cultural differences in the Social Concerns factor. MethodsaaK-ASI-3 was administered to non clinical samples in Korea. Internal consistency, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA) were undertaken to examine the factorial structure and reliability of the K-ASI-3. ResultsaaResults from CFA comparing our data to factor solutions commonly reported as representative of European-American samples indicated an adequate fit. The K-ASI-3 showed good performance on the indices of internal consistency and concurrent validity. In addition, using regression analyses, we found the Social Concerns factor is most strongly related to life satisfaction and worry. However, we found no evidence that Korean college students express more Social Concerns than their European Caucasian counterparts. ConclusionaaThe authors demonstrate that the K-ASI-3 has highly internally consistent and psychometrically sound items, and that it reliably measures three lower-order domains assessing Physical, Social, and Cognitive Concerns. Psychiatry Investig 2012;9:45-53 Key Wordsaa�Anxiety sensitivity, Factor structure, Anxiety Sensitivity Index-3, Cross-cultural difference, Korean