309 research outputs found
Characterising the tumour morphological response to therapeutic intervention:an ex vivo model
In cancer, morphological assessment of histological tissue samples is a fundamental part of both diagnosis and prognosis. Image analysis offers opportunities to support that assessment through quantitative metrics of morphology. Generally, morphometric analysis is carried out on two dimensional tissue section data and so only represents a small fraction of any tumour. We present a novel application of three-dimensional (3D) morphometrics for 3D imaging data obtained from tumours grown in a culture model. Minkowski functionals, a set of measures that characterise geometry and topology in n-dimensional space, are used to quantify tumour topology in the absence of and in response to therapeutic intervention. These measures are used to stratify the morphological response of tumours to therapeutic intervention. Breast tumours are characterised by estrogen receptor (ER) status, human epidermal growth factor receptor (HER)2 status and tumour grade. Previously, we have shown that ER status is associated with tumour volume in response to tamoxifen treatment ex vivo. Here, HER2 status is found to predict the changes in morphology other than volume as a result of tamoxifen treatment ex vivo. Finally, we show the extent to which Minkowski functionals might be used to predict tumour grade.Minkowski functionals are generalisable to any 3D data set, including in vivo and cellular systems. This quantitative topological analysis can provide a valuable link among biomarkers, drug intervention and tumour morphology that is complementary to existing, non-morphological measures of tumour response to intervention and could ultimately inform patient treatment
Educational audit on drug dose calculation learning in a Tanzanian school of nursing
Background: Patient safety is a key concern for nurses; ability to
calculate drug doses correctly is an essential skill to prevent and
reduce medication errors. Literature suggests that nurses\u2019 drug
calculation skills should be monitored. Objective: The aim of the study
was to conduct an educational audit on drug dose calculation learning
in a Tanzanian school of nursing. Specific objectives were to assess
learning from targeted teaching, to identify problem areas in
performance and to identify ways in which these problem areas might be
addressed. Methods: A total of 268 registered nurses and nursing
students in two year groups of a nursing degree programme were the
subjects for the audit; they were given a pretest, then four hours of
teaching, a post-test after two weeks and a second post-test after
eight weeks. Results: There was a statistically significant improvement
in correct answers in the first post-test, but none between the first
and second post-tests. Particular problems with drug calculations were
identified by the nurses / students, and the teacher; these identified
problems were not congruent. Conclusion: Further studies in different
settings using different methods of teaching, planned continuing
education for all qualified nurses, and appropriate pass marks for
students in critical skills are recommended
Child vulnerability in the Iraqw and Datoga of Haydom village, Northern Tanzania
Child vulnerability is a complex human phenomenon that varies contextually. This thesis explores the views of Iraqw and Datoga residents of Haydom village relating to child vulnerability using a concept analysis. The study is a mixed methods study carried out in three stages. The first stage is a non-empirical qualitative literature review; findings from this stage were used to construct questions for the subsequent stage of the study. The second stage of the study is empirical and qualitative, using a focused ethnographic approach. Semi-structured interviews were conducted with thirty-two adults of the Iraqw and Datoga ethnic groups. Five main themes emerged from a thematic analysis of these interviews; 1) antecedents: lack of resources, 2) contributing antecedents: intentional mistreatment, 3) defining attributes: deprivations in a young individual, 4) consequences: losses suffered, and 5) strategies: dealing with deprivation. Informantsâ views were used to construct items for a questionnaire, which was administered in the third stage of the study. This quantitative stage involved eighty young adult respondents of the Iraqw and Datoga ethnic groups. The data in the third stage of the study was analysed statistically, and generally supported the findings of the second stage of the study.
Significant Haydom findings congruent with the literature include that poverty and parental alcoholism are antecedents for child vulnerability, that fathers may be unreliable and that some children cope by persevering and working hard. Findings in Haydom that differ from the literature include the following: some people perceive large family size as a protective factor handicapped, illegitimate and foster children may be mistreated former wealth may predispose to lacking coping skills children as a resource child vulnerability has potential for deterioration, stasis or improvement informants suggested a limited range of strategies, including institutional care, with little stress on volunteerism unrelated fostering is unusual but acceptable to many people.
This study recommends local identification of and advocacy for vulnerable childrenâs rights, and planning of evidence based but culturally acceptable strategies to help them.Health StudiesD. Litt. et Phil. (Health Studies
Complete Genome Sequences of Four Putatively Antibiotic-Producing Bacteria Isolated from Soil in Arkansas, USA
Soil bacteria can be a valuable source of antimicrobial compounds. Here, we report the complete genomes of four soil bacteria that were isolated by undergraduate microbiology students as part of a course-based research experience. These genomes were assembled using a hybrid approach combining paired-end Illumina reads with Oxford Nanopore Technologies MinION reads
Knowledge of pre-eclampsia in women living in Makole Ward, Dodoma, Tanzania.
Background: Pre-eclampsia is a hypertensive disorder specific to
pregnancy responsible for significant maternal morbidity and mortality
in Africa. The majority of deaths related to pre-eclampsia could be
avoided with timely and effective care. \u201cPhase one delays\u201d
arise because of lack of knowledge. Objectives: This study aimed to
assess the knowledge levels of women living in Makole ward, comparing
respondent subgroups with different demographic characteristics. It
also aimed to compare knowledge levels in respect to six subtopics of
pre-eclampsia. This was to allow for planning of appropriate activities
to reduce delays in seeking health care. Methods: This study surveyed
200 adult women randomly identified in the community. They were asked
36 questions on preeclampsia requiring yes / no answers. The data was
analysed quantitatively. Results: Overall knowledge levels were low
with an average of 41% of correct answers. Minor differences in the
knowledge levels of demographic subgroups were found. Statistically
significant differences were identified between sub-topics of
preeclampsia; signs and symptoms were the least well known. Conclusion:
Educational systems (formal and informal) are failing to provide
communities with potentially life-saving information. Health centre,
community and school based education programmes are recommended
Neural Processing of Emotional Musical and Nonmusical Stimuli in Depression
Background Anterior cingulate cortex (ACC) and striatum are part of the emotional neural circuitry implicated in major depressive disorder (MDD). Music is often used for emotion regulation, and pleasurable music listening activates the dopaminergic system in the brain, including the ACC. The present study uses functional MRI (fMRI) and an emotional nonmusical and musical stimuli paradigm to examine how neural processing of emotionally provocative auditory stimuli is altered within the ACC and striatum in depression.
Method Nineteen MDD and 20 never-depressed (ND) control participants listened to standardized positive and negative emotional musical and nonmusical stimuli during fMRI scanning and gave subjective ratings of valence and arousal following scanning.
Results ND participants exhibited greater activation to positive versus negative stimuli in ventral ACC. When compared with ND participants, MDD participants showed a different pattern of activation in ACC. In the rostral part of the ACC, ND participants showed greater activation for positive information, while MDD participants showed greater activation to negative information. In dorsal ACC, the pattern of activation distinguished between the types of stimuli, with ND participants showing greater activation to music compared to nonmusical stimuli, while MDD participants showed greater activation to nonmusical stimuli, with the greatest response to negative nonmusical stimuli. No group differences were found in striatum.
Conclusions These results suggest that people with depression may process emotional auditory stimuli differently based on both the type of stimulation and the emotional content of that stimulation. This raises the possibility that music may be useful in retraining ACC function, potentially leading to more effective and targeted treatments
The occupation of a box as a toy model for the seismic cycle of a fault
We illustrate how a simple statistical model can describe the quasiperiodic
occurrence of large earthquakes. The model idealizes the loading of elastic
energy in a seismic fault by the stochastic filling of a box. The emptying of
the box after it is full is analogous to the generation of a large earthquake
in which the fault relaxes after having been loaded to its failure threshold.
The duration of the filling process is analogous to the seismic cycle, the time
interval between two successive large earthquakes in a particular fault. The
simplicity of the model enables us to derive the statistical distribution of
its seismic cycle. We use this distribution to fit the series of earthquakes
with magnitude around 6 that occurred at the Parkfield segment of the San
Andreas fault in California. Using this fit, we estimate the probability of the
next large earthquake at Parkfield and devise a simple forecasting strategy.Comment: Final version of the published paper, with an erratum and an
unpublished appendix with some proof
Soil respiration in a northeastern US temperate forest: a 22âyear synthesis
To better understand how forest management, phenology, vegetation type, and actual and simulated climatic change affect seasonal and interâannual variations in soil respiration (Rs), we analyzed more than 100,000 individual measurements of soil respiration from 23 studies conducted over 22 years at the Harvard Forest in Petersham, Massachusetts, USA. We also used 24 siteâyears of eddyâcovariance measurements from two Harvard Forest sites to examine the relationship between soil and ecosystem respiration (Re).
Rs was highly variable at all spatial (respiration collar to forest stand) and temporal (minutes to years) scales of measurement. The response of Rs to experimental manipulations mimicking aspects of global change or aimed at partitioning Rs into component fluxes ranged from â70% to +52%. The response appears to arise from variations in substrate availability induced by changes in the size of soil C pools and of belowground C fluxes or in environmental conditions. In some cases (e.g., logging, warming), the effect of experimental manipulations on Rs was transient, but in other cases the time series were not long enough to rule out longâterm changes in respiration rates. Interâannual variations in weather and phenology induced variation among annual Rs estimates of a magnitude similar to that of other drivers of global change (i.e., invasive insects, forest management practices, N deposition). At both eddyâcovariance sites, aboveground respiration dominated Re early in the growing season, whereas belowground respiration dominated later. Unusual aboveground respiration patternsâhigh apparent rates of respiration during winter and very low rates in midâtoâlate summerâat the Environmental Measurement Site suggest either bias in Rs and Re estimates caused by differences in the spatial scale of processes influencing fluxes, or that additional research on the hardâtoâmeasure fluxes (e.g., wintertime Rs, unaccounted losses of CO2 from eddy covariance sites), daytime and nighttime canopy respiration and its impacts on estimates of Re, and independent measurements of flux partitioning (e.g., aboveground plant respiration, isotopic partitioning) may yield insight into the unusually high and low fluxes. Overall, however, this dataârich analysis identifies important seasonal and experimental variations in Rs and Re and in the partitioning of Re aboveâ vs. belowground
Soil respiration in a northeastern US temperate forest: a 22âyear synthesis
To better understand how forest management, phenology, vegetation type, and actual and simulated climatic change affect seasonal and interâannual variations in soil respiration (Rs), we analyzed more than 100,000 individual measurements of soil respiration from 23 studies conducted over 22 years at the Harvard Forest in Petersham, Massachusetts, USA. We also used 24 siteâyears of eddyâcovariance measurements from two Harvard Forest sites to examine the relationship between soil and ecosystem respiration (Re).
Rs was highly variable at all spatial (respiration collar to forest stand) and temporal (minutes to years) scales of measurement. The response of Rs to experimental manipulations mimicking aspects of global change or aimed at partitioning Rs into component fluxes ranged from â70% to +52%. The response appears to arise from variations in substrate availability induced by changes in the size of soil C pools and of belowground C fluxes or in environmental conditions. In some cases (e.g., logging, warming), the effect of experimental manipulations on Rs was transient, but in other cases the time series were not long enough to rule out longâterm changes in respiration rates. Interâannual variations in weather and phenology induced variation among annual Rs estimates of a magnitude similar to that of other drivers of global change (i.e., invasive insects, forest management practices, N deposition). At both eddyâcovariance sites, aboveground respiration dominated Re early in the growing season, whereas belowground respiration dominated later. Unusual aboveground respiration patternsâhigh apparent rates of respiration during winter and very low rates in midâtoâlate summerâat the Environmental Measurement Site suggest either bias in Rs and Re estimates caused by differences in the spatial scale of processes influencing fluxes, or that additional research on the hardâtoâmeasure fluxes (e.g., wintertime Rs, unaccounted losses of CO2 from eddy covariance sites), daytime and nighttime canopy respiration and its impacts on estimates of Re, and independent measurements of flux partitioning (e.g., aboveground plant respiration, isotopic partitioning) may yield insight into the unusually high and low fluxes. Overall, however, this dataârich analysis identifies important seasonal and experimental variations in Rs and Re and in the partitioning of Re aboveâ vs. belowground
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