COMPARING ANALYSES OF UNBALANCED SPLIT-PLOT EXPERIMENTS

Several procedures for constructing confidence intervals and testing hypotheses about fixed effects in unbalanced split-plot experiments have previously been presented and discussed by Remmenga and Johnson. They recommended a few of the procedures they considered as useful and reliable procedures. Since the advent of the SAS® MIXED procedure, mixed model analyses with REML estimates of the variance components are easily accessible to researchers. This paper compares the analysis of unbalanced split-plot experiments using mixed model procedures with REML estimates of the variance components to the previously established procedures by means of additional simulation studies

Speech and language therapy versus placebo or no intervention for speech problems in Parkinson's disease

Parkinson's disease patients commonly suffer from speech and vocal problems including dysarthric speech, reduced loudness and loss of articulation. These symptoms increase in frequency and intensity with progression of the disease). Speech and language therapy (SLT) aims to improve the intelligibility of speech with behavioural treatment techniques or instrumental aids

Constraints on Mars Aphelion Cloud Belt Phase Function and Ice Crystal Geometries

This study constrains the lower bound of the scattering phase function of Martian water ice clouds (WICs) through the implementation of a new observation aboard the Mars Science Laboratory (MSL). The Phase Function Sky Survey (PFSS) was a multiple pointing all-sky observation taken with the navigation cameras (Navcam) aboard MSL. The PFSS was executed 35 times during the Aphelion Cloud Belt (ACB) season of Mars Year 34 over a solar longitude range of L_s=61.4{\deg}-156.5{\deg}. Twenty observations occurred in the morning hours between 06:00 and 09:30 LTST, and 15 runs occurred in the evening hours between 14:30 and 18:00 LTST, with an operationally required 2.5 hour gap on either side of local noon due the sun being located near zenith. The resultant WIC phase function was derived over an observed scattering angle range of 18.3{\deg} to 152.61{\deg}, normalized, and compared with 9 modeled phase functions: seven ice crystal habits and two Martian WIC phase functions currently being implemented in models. Through statistical chi-squared probability tests, the five most probable ice crystal geometries observed in the ACB WICs were aggregates, hexagonal solid columns, hollow columns, plates, and bullet rosettes with p-values greater than or equal to 0.60, 0.57,0.56,0.56, and 0.55, respectively. Droxtals and spheres had p-values of 0.35, and 0.2, making them less probable components of Martian WICs, but still statistically possible ones. Having a better understanding of the ice crystal habit and phase function of Martian water ice clouds directly benefits Martian climate models which currently assume spherical and cylindrical particles.Comment: Accepted Manuscript by Planetary and Space Scienc

Mycobacterium tuberculosis evasion of Guanylate Binding Protein-mediated host defense in mice requires the ESX1 secretion system [preprint]

Cell-intrinsic immune mechanisms control intracellular pathogens that infect eukaryotes. The intracellular pathogen Mycobacterium tuberculosis (Mtb) evolved to withstand cell-autonomous immunity to cause persistent infections and disease. A potent inducer of cell-autonomous immunity is the lymphocyte-derived cytokine IFNγ. While the production of IFNγ by T cells is essential to protect against Mtb, it is not capable of fully eradicating Mtb infection. This suggests that Mtb evades a subset of IFNγ-mediated antimicrobial responses, yet what mechanisms Mtb resists remains unclear. The IFNγ-inducible Guanylate binding proteins (GBPs) are key host defense proteins able to control infections with intracellular pathogens. GBPs were previously shown to directly restrict Mycobacterium bovis BCG yet their role during Mtb infection has remained unknown. Here, we examine the importance of a cluster of five GBPs on mouse chromosome 3 in controlling Mycobacterial infection. While M. bovis BCG is directly restricted by GBPs, we find that the GBPs on chromosome 3 do not contribute to the control of Mtb replication or the associated host response to infection. The differential effects of GBPs during Mtb versus M. bovis BCG infection is at least partially explained by the absence of the ESX1 secretion system from M. bovis BCG, since Mtb mutants lacking the ESX1 secretion system become similarly susceptible to GBP-mediated immune defense. Therefore, this specific genetic interaction between the murine host and Mycobacteria reveals a novel function for the ESX1 virulence system in the evasion of GBP-mediated immunity

Patient experiences of swallowing exercises after head and neck cancer:A qualitative study examining barriers and facilitators using behaviour change theory

Poor patient adherence to swallowing exercises is commonly reported in the dysphagia literature on patients treated for head and neck cancer. Establishing the effectiveness of exercise interventions for this population may be undermined by patient non-adherence. The purpose of this study was to explore the barriers and facilitators to exercise adherence from a patient perspective, and to determine the best strategies to reduce the barriers and enhance the facilitators. In-depth interviews were conducted on thirteen patients. We used a behaviour change framework and model [Theoretical domains framework and COM-B (Capability-opportunity-motivation-behaviour) model] to inform our interview schedule and structure our results, using a content analysis approach. The most frequent barrier identified was psychological capability. This was highlighted by patient reports of not clearly understanding reasons for the exercises, forgetting to do the exercises and not having a system to keep track. Other barriers included feeling overwhelmed by information at a difficult time (lack of automatic motivation) and pain and fatigue (lack of physical capability). Main facilitators included having social support from family and friends, the desire to prevent negative consequences such as long-term tube feeding (reflective motivation), having the skills to do the exercises (physical capability), having a routine or trigger and receiving feedback on the outcome of doing exercises (automatic motivation). Linking these findings back to the theoretical model allows for a more systematic selection of theory-based strategies that may enhance the design of future swallowing exercise interventions for patients with head and neck cancer

Patient experiences of swallowing exercises after head and neck cancer:A qualitative study examining barriers and facilitators using behaviour change theory

Poor patient adherence to swallowing exercises is commonly reported in the dysphagia literature on patients treated for head and neck cancer. Establishing the effectiveness of exercise interventions for this population may be undermined by patient non-adherence. The purpose of this study was to explore the barriers and facilitators to exercise adherence from a patient perspective, and to determine the best strategies to reduce the barriers and enhance the facilitators. In-depth interviews were conducted on thirteen patients. We used a behaviour change framework and model [Theoretical domains framework and COM-B (Capability-opportunity-motivation-behaviour) model] to inform our interview schedule and structure our results, using a content analysis approach. The most frequent barrier identified was psychological capability. This was highlighted by patient reports of not clearly understanding reasons for the exercises, forgetting to do the exercises and not having a system to keep track. Other barriers included feeling overwhelmed by information at a difficult time (lack of automatic motivation) and pain and fatigue (lack of physical capability). Main facilitators included having social support from family and friends, the desire to prevent negative consequences such as long-term tube feeding (reflective motivation), having the skills to do the exercises (physical capability), having a routine or trigger and receiving feedback on the outcome of doing exercises (automatic motivation). Linking these findings back to the theoretical model allows for a more systematic selection of theory-based strategies that may enhance the design of future swallowing exercise interventions for patients with head and neck cancer

Age Differences in Behavior and PET Activation Reveal Differences in Interference Resolution in Verbal Working Memory

Older adults were tested on a verbal working memory task that used the item-recognition paradigm. On some trials of this task, response-conflict was created by presenting test-items that were familiar but were not members of a current set of items stored in memory. These items required a negative response, but their familiarity biased subjects toward a positive response. Younger subjects show an interference effect on such trials, and this interference is accompanied by activation of a region of left lateral prefrontal cortex. However, there has been no evidence that the activation in this region is causally related to the interference that the subjects exhibit. In the present study, we demonstrate that older adults show more behavioral interference than younger subjects on this task, and they also show no reliable activation at the same lateral prefrontal site. This leads to the conclusion that this prefrontal site is functionally involved in mediating resolution among conflicting responses or among conflicting representations in working memory