Association of white matter hyperintensities and gray matter volume with cognition in older individuals without cognitive impairment

Both presence of white matter hyperintensities (WMH) and smaller total gray matter volume on brain magnetic resonance imaging (MRI) are common findings in old age, and contribute to impaired cognition. We tested whether total WMH volume and gray matter volume had independent associations with cognition in community-dwelling individuals without dementia or mild cognitive impairment (MCI). We used data from participants of the Rush Memory and Aging Project. Brain MRI was available in 209 subjects without dementia or MCI (mean age 80; education = 15 years; 74 % women). WMH and gray matter were automatically segmented, and the total WMH and gray matter volumes were measured. Both MRI-derived measures were normalized by the intracranial volume. Cognitive data included composite measures of five different cognitive domains, based on 19 individual tests. Linear regression analyses, adjusted for age, sex, and education, were used to examine the relationship of logarithmically-transformed total WMH volume and of total gray matter volume to cognition. Larger total WMH volumes were associated with lower levels of perceptual speed (p < 0.001), but not with episodic memory, semantic memory, working memory, or visuospatial abilities (all p > 0.10). Smaller total gray matter volumes were associated with lower levels of perceptual speed (p = 0.013) and episodic memory (p = 0.001), but not with the other three cognitive domains (all p > 0.14). Larger total WMH volume was correlated with smaller total gray matter volume (p < 0.001). In a model with both MRI-derived measures included, the relation of WMH to perceptual speed remained significant (p < 0.001), while gray matter volumes were no longer related (p = 0.14). This study of older community-dwelling individuals without overt cognitive impairment suggests that the association of larger total WMH volume with lower perceptual speed is independent of total gray matter volume. These results help elucidate the pathological processes leading to lower cognitive function in aging

Building the capacity to solve complex health challenges in Sub-Saharan Africa : CARTA’s multidisciplinary PhD training

Objectives: To develop a curriculum (Joint Advanced Seminars- JAS) that produced PhD fellows who understood that health is an outcome of multiple determinants within complex environments and that approaches from a range of disciplines is required to address health and development within the Consortium for Advanced Research Training in Africa. We sought to attract PhD fellows, supervisors and teaching faculty from a range of disciplines into the program. Methods: Multidisciplinary teams developed the JAS curriculum. CARTA PhD fellowships were open to academics in consortium member institutions, irrespective of primary discipline, interested in doing a PhD in public and population health. Supervisors and JAS faculty were recruited from CARTA institutions. We use routine JAS evaluation data (closed and open ended questions) collected from PhD fellows at every JAS, a survey of one CARTA cohort and an external evaluation of CARTA to assess the impact of the JAS curriculum on learning. Results: We describe our pedagogic approach arguing its centrality to an appreciation of multiple disciplines and illustrate how it promotes working in multidisciplinary ways. CARTA has attracted PhD fellows, supervisors and JAS teaching faculty from across a range of disciplines. Evaluations indicate PhD fellows have a greater appreciation of how disciplines other than their own are important to understand health and its determinants and an appreciation and capacity to employ mixed methods research. Conclusions: In the short-term, we have been effective in promoting an understanding of multidisciplinarity resulting in fellows using methods from beyond their discipline of origin. This curriculum has international application

Worldline CPT and massless supermultiplets

The action for a massless particle in 4D Minkowski space–time has a worldline-time reversing symmetry corresponding to CPT invariance of the quantum theory. The analogous symmetry of the $\mathscr{N}$-extended superparticle is shown to be anomalous when $\mathscr{N}$ is odd; in the supertwistor formalism this is because a CPT-violating worldline-Chern–Simons term is needed to preserve the chiral $\textbf{U(1)}$ gauge invariance. This accords with the fact that no massless $\mathscr{N}$=1 super-Poincaré irrep is CPT-self-conjugate. There is a CPT self-conjugate supermultiplet when $\mathscr{N}$ is even, but it has $\textbf{2}$$^{\mathscr{N}+1}$ states when $\frac{1}{2}$$\mathscr{N}$ is odd (e.g. the $\mathscr{N}$=2 hypermultiplet) in contrast to just $\textbf{2}$$^{\mathscr{N}}$ when $\frac{1}{2}$$\mathscr{N}$ is even (e.g. the $\mathscr{N}$=4 Maxwell supermultiplet). This is shown to follow from a Kramers degeneracy of the superparticle state space when $\frac{1}{2}$$\mathscr{N}$ is odd.A.S. Arvanitakis and P. K. Townsend acknowledge support from the UK Science and Technology Facilities Council (grant ST/L000385/1).A.S. Arvanitakis also acknowledges support from Clare Hall College, Cambridge, and from the Cambridge Trust

The use of Bacillus thuringiensis and Neem alternation on Plutella xylostella (Lepidoptera: Plutellidae) and its effects on natural enemies in cabbage production

The diamondback moth (DBM), Plutel/a xylostella (L.) is a major pest of cabbage in Senegal. Chemical control is the most commonly used control method despite its environmental and health issues. Bacillus thuringiensis (Bt) and Neembased products are considered as relevant alternatives to synthetic chemical insecticides. The aim of this study was to assess the effect of the alternation of Bt and Neem (Azadirachta indica) on P. xylostella and its effect on parasitoids compared to sole applications of Bt, Neem and Dimethoate. Plants treated with Dimethoate recorded three times more P. xylostella compared to applications of Bt, Bt/Neem and Neem. Results showed that although there were no significant differences between Bt, Bt/Neem and Neem, populations of P. xylostella were considerably reduced in tbese treatments as compared to Dimethoate and control. Four parasitoid species were recorded of which two species Oomyzus sokolowskii and Apanteles litae were important both in terms of abundance and parasitism. The parasitism rate was higher in the Neem treatment. The correlatioo between abundance of P. xyloste/la and parasitism rate was observed in all the treatments except that of Dimethoate and was much stronger in Bt/Neem and Neem. This study suggests that in the absence of chemical insecticides, parasitoids contribute significantly in DBM population control. Also the use of only four alternated applications of Bt and neem is as effective as sole treatmeots in the control of P. xylostella. This approach which îs more environmeotally friendly seems to be also more cost effective to farmers

Pauli-Lubanski, supertwistors, and the superspinning particle

We present a novel construction of the super-Pauli-Lubanski pseudo-vector for 4D supersymmetry and show how it arises naturally from the spin-shell constraints in the supertwistor formulation of superparticle dynamics. We illustrate this result in the context of a simple classical action for a “superspinning particle” of superspin 1/2. We then use an Sl(2;K)-spinor formalism for K=ℝ,ℂ,ℍ to unify our 4D results with previous results for 3D and 6D

Systematic review of factors influencing patient and practitioner delay in diagnosis of upper gastrointestinal cancer

As knowledge on the causation of cancers advances and new treatments are developed, early recognition and accurate diagnosis becomes increasingly important. This review focused on identifying factors influencing patient and primary care practitioner delay for upper gastrointestinal cancer. A systematic methodology was applied, including extensive searches of the literature published from 1970 to 2003, systematic data extraction, quality assessment and narrative data synthesis. Included studies were those evaluating factors associated with the time interval between a patient first noticing a cancer symptom and presenting to primary care, between a patient first presenting to primary care and being referred to secondary care, or describing an intervention designed to reduce those intervals. Twenty-five studies were included in the review. Studies reporting delay intervals demonstrated that the patient phase of delay was greater than the practitioner phase, whilst patient-related research suggests that recognition of symptom seriousness is more important than recognition of the presence of the symptom. The main factors related to practitioner delay were misdiagnosis, application and interpretation of tests, and the confounding effect of existing disease. Greater understanding of patient factors is required, along with evaluation of interventions to ensure appropriate diagnosis, examination and investigation

Modulation of 11β-hydroxysteroid dehydrogenase as a strategy to reduce vascular inflammation

Atherosclerosis is a chronic inflammatory disease in which initial vascular damage leads to extensive macrophage and lymphocyte infiltration. Although acutely glucocorticoids suppress inflammation, chronic glucocorticoid excess worsens atherosclerosis, possibly by exacerbating systemic cardiovascular risk factors. However, glucocorticoid action within the lesion may reduce neointimal proliferation and inflammation. Glucocorticoid levels within cells do not necessarily reflect circulating levels due to pre-receptor metabolism by 11β-hydroxysteroid dehydrogenases (11β-HSDs). 11β-HSD2 converts active glucocorticoids into inert 11-keto forms. 11β-HSD1 catalyses the reverse reaction, regenerating active glucocorticoids. 11β-HSD2-deficiency/ inhibition causes hypertension, whereas deficiency/ inhibition of 11β-HSD1 generates a cardioprotective lipid profile and improves glycemic control. Importantly, 11β-HSD1-deficiency/ inhibition is atheroprotective, whereas 11β-HSD2-deficiency accelerates atherosclerosis. These effects are largely independent of systemic risk factors, reflecting modulation of glucocorticoid action and inflammation within the vasculature. Here, we consider whether evidence linking the 11β-HSDs to vascular inflammation suggests these isozymes are potential therapeutic targets in vascular injury and atherosclerosis

The Brodmann Area 39/40 of the Brain in Alzheimer’s, Mild Cognitive Impairment, and No Cognitive Impairment Subjects at Advanced Age Demonstrate Comparable Levels of Blood-Brain Barrier Breach

• Alzheimer’s disease (AD) is one of the most common form of dementia • Mild cognitive impairment (MCI), specifically amnestic subtype, more likely to progress to AD • Pathogenesis Theories: o Accumulation of amyloid-beta peptides and neurofibrillary tangles containing hyperphosphorylated neuronal tau protein o Blood Brain Barrier (BBB) dysfunction is associated with AD pathogenesis • Brodmann area 39/40: regions of parietal cortex are responsible for language, spatial cognition, memory retrieval, attention, phonological processing, and emotional processing • Hypothesis: An increased BBB permeability in Brodmann area 39/40 of AD and age-matched MCI and no cognitive impairment (NCI) subject