Pattern Of Symptom Development Research Articles

Development of Plasmodiophora brassicae in the root cortex of cabbage over time

Pathogen development in the root cortex of three cabbage (Brassica oleracea var. capitata) cultivars that differed in clubroot reaction (susceptible ‘Bronco’, partially resistant ‘B-2819’, resistant ‘Tekila’) was assessed over time in plants inoculated with 1 × 106, 1 × 107 and 2 × 108 spores mL−1 of Plasmodiophora brassica in a controlled environment study. Cortical colonization and symptom development in ‘Bronco’ and ‘B-2819’ were affected by inoculum concentration. When inoculated at 1 × 106 and 1 × 107 spores·mL−1, clubroot levels were generally higher on ‘Bronco’ relative to ‘B-2819’. However, there were no differences at 2 × 108 spores because incidence and severity in both ‘Bronco’ and ‘B-2819’ were near the maximum. Similarly, the area colonized by P. brassicae (%) on root cross-sections was much higher in ‘Bronco’ than ‘B-2819’ at 1 × 106 spores, but differences in cortical colonization, if any, were small at higher inoculum concentrations. The concentration of P. brassicae DNA in inoculated roots (assessed using qPCR) was higher in ‘Bronco’ relative to ‘B-2819’ at 1 × 106 spores, and there were no differences between the two cultivars at the highest inoculum concentration, which matched with the pattern of symptom development. In contrast, symptom development in ‘B-2819’ lagged behind increases in DNA level at 1 × 107 spores. No cortical infection was observed in ‘Tekila’ at the two lower inoculum concentrations, and only a few spindle clubs developed at the highest concentration. These results demonstrated that this source of partial resistance was strongly affected by inoculum concentration, while strong resistance was much less affected.

Patterns of symptom development in patients with motor neuron disease

Objective: To investigate whether symptom development in motor neuron disease (MND) is a random or organized process. Methods: Six hundred patients with amyotrophic lateral sclerosis (ALS), upper motor neuron (UMN) or lower motor neuron (LMN) phenotypes were invited for a questionnaire concerning symptom development. A binomial test was used to examine distribution of symptoms from site of onset. Development of symptoms over time was evaluated by Kaplan-Meier analysis. Results: There were 470 respondents (ALS = 254; LMN = 100; UMN = 116). Subsequent symptoms were more often in the contralateral limb following unilateral limb onset (ALS: arms p = 1.05 × 10−8, legs p < 2.86 × 10−15; LMN phenotype: arms p = 6.74 × 10−9, legs p = 6.26 × 10−6; UMN phenotype: legs p = 4.07 × 10−14). In patients with limb onset, symptoms occurred significantly faster in the contralateral limb, followed by the other limbs and lastly by the bulbar region. Patterns of non-contiguous symptom development were also reported: leg symptoms followed bulbar onset in 30%, and bulbar symptoms followed leg onset in 11% of ALS patients. Conclusions: Preferred spread of symptoms from one limb to the contralateral limb, and to adjacent sites appears to be a characteristic of MND phenotypes, suggesting that symptom spread is organized, possibly involving axonal connectivity. Non-contiguous symptom development, however, is not uncommon, and may involve other factors.

A Decade of War: Prospective Trajectories of Posttraumatic Stress Disorder Symptoms Among Deployed US Military Personnel and the Influence of Combat Exposure.

Posttraumatic stress disorder (PTSD) is a common psychiatric disorder among service members and veterans. The clinical course of PTSD varies between individuals, and patterns of symptom development have yet to be clearly delineated. Previous studies have been limited by convenience sampling, short follow-up periods, and the inability to account for combat-related trauma. To determine the trajectories of PTSD symptoms among deployed military personnel with and without combat exposure, we used data from a population-based representative sample of 8,178 US service members who participated in the Millennium Cohort Study from 2001 to 2011. Using latent growth mixture modeling, trajectories of PTSD symptoms were determined in the total sample, as well as in individuals with and without combat exposure, respectively. Overall, 4 trajectories of PTSD were characterized: resilient, pre-existing, new-onset, and moderate stable. Across all trajectories, combat-deployed service members diverged from non-combat-deployed service members, even after a single deployment. The former also generally had higher PTSD symptoms. Based on the models, nearly 90% of those without combat exposure remained resilient over the 10-year period, compared with 80% of those with combat exposure. Findings demonstrate that although the clinical course of PTSD symptoms shows heterogeneous patterns of development, combat exposure is uniformly associated with poor mental health.

Effect of seeding date on development of clubroot in short-season Brassica crops

Recent studies on the effect of temperature on clubroot of Brassica spp., caused by Plasmodiophora brassicae, have demonstrated that temperature has an important impact on each component of the disease cycle under controlled conditions. The current study was conducted to assess the impact of temperature regime on clubroot incidence and severity on two short-season Asian vegetable crops, Shanghai pak choy (B. rapa subsp. chinensis var. communis) and Chinese flowering cabbage (B. rapa subsp. chinensis var. utilis) under field conditions. Each crop was seeded at about monthly intervals from May to September on a naturally infested site near Bradford, Ontario in 2008 and 2009. A soil-drench treatment with cyazofamid fungicide (trade name Ranman® 400 SC) was included at each seeding date to assess the interaction of fungicide and temperature. Clubroot severity was assessed at weekly intervals from 2–3 wk after planting until about 6 wk after planting using a 0–3 scale. Clubroot incidence and severity were consistently higher on Shanghai pak choy than Chinese flowering cabbage, but both host crops exhibited a similar pattern of symptom development. Clubroot severity was highest in the July seeding (warmest mean temperature), slightly lower in June and August, and lowest in the May and September seeding dates (lowest temperatures). Clubroot levels were also positively correlated with rainfall. Cyazofamid fungicide consistently reduced clubroot levels. We conclude that producers of short-season crops can select seeding dates to avoid losses from clubroot, even in heavily infested fields. Both moderate soil temperatures (17–26 °C) and adequate soil moisture must be present for the development of severe clubroot.

Long‐distance movement of Cauliflower mosaic virus and host defence responses in Arabidopsis follow a predictable pattern that is determined by the leaf orthostichy

Long-distance virus transport takes place through the vascular system and is dependent on the movement of photoassimilates. Here, patterns of symptom development, virus movement and gene expression were analysed in Arabidopsis following inoculation with Cauliflower mosaic virus (CaMV) on a single leaf. Virus accumulation and expression of markers for the salicylic acid (SA) and ethylene/jasmonate (Et/JA) defence pathways, PR-1 and PDF1.2, were analysed on a leaf-by-leaf basis by real-time reverse transcription polymerase chain reaction (qRT-PCR). Virus spread followed a strictly defined pattern identical to that of a source-sink relationship. This was exploited to study differences between local and systemic defence responses in a developmental and spatial manner. In infected plants, PR-1 transcripts accumulated primarily but not exclusively in leaves with a direct vascular connection to the inoculated leaf. Abundances fell significantly as virus accumulated. By contrast, PDF1.2 transcripts were significantly lower than in controls in all leaves at early stages of infection, but recovered as virus accumulated. Virus and PR-1 transcript abundances are negatively correlated, and SA- and Et/JA-mediated signalling of gene expression occurs independently of the presence of virus. Although SA-dependent signalling responses were mainly linked to the orthostichy, Et/JA-dependent responses were independent of vascular connections.

Calcium Deficiency Symptoms of Heartleaf Philodendron

Abstract Calcium deficiency symptoms of heartleaf philodendron (Philodendron scandens ssp. oxycardium) were reported to occur first on the vine's basal leaves, with the tip or uppermost leaves the last to develop symptoms (1). This pattern of symptom development was interpreted to indicate that philodendron was an exception to the generalization that Ca is immobile in plants, i.e., in philodendron, Ca was translocated from basal to upper leaves (5). Since Ca deficiency symptoms occur in meristematic areas (such as shoot and root tips), Ca is considered immobile in plants (2). Thus, the report of Ca deficiency symptoms on basal leaves of philodendron (1) was indeed exceptional. Unfortunately, there was no report of the recovery of the deficient plants when fertilized with Ca, nor any Ca analysis of philodendron tissue, to confirm that Ca deficiency was the cause of the observed symptoms (1) and to support the conclusion that Ca was mobile (5). The purpose of this study was to produce Ca deficiency symptoms in heartleaf philodendron to determine if Ca deficiency symptoms occur on basal leaves, as originally reported (1).

The Evaluation of a Questionnaire Measuring Severity of Alcohol Dependence*

This paper is concerned with the evaluation of the Hilton Drinking Behaviour Questionnaire (HDBQ), which is based on the proposition that although there are wide variations in the types of problems caused by alcohol abuse there are certain symptoms which are generally considered to indicate ‘alcoholism’. Also that there is an identifiable pattern of symptom development in the acquisition of dependence.The HDBQ proved to be a unidim.ensional scale which was valid and reliable as a m.easure of alcoholfsm, All items significantly discritninated between the alcoholic and control groups, and total scores correlated highly with those on the Alcadd test and with quantity-frequency measures of drinking. The theoretical and clinical implication of the results are discussed.