Food Security Crop Price Transmission and Formation in Nigeria

The three studies in this dissertation explore the current conditions and operations of markets for seven key food security crops (cassava, cowpeas, maize, millet, rice, sorghum, and yams) in Nigeria. Chapter 2 is an empirical analysis of the current agricultural statistics system in Nigeria. A number of sources gather and report agricultural statistics for the country. Since there has not been an agricultural census implemented there for multiple decades, however, there is no objective source for data verification. Therefore, this study uses two additional types of “on the ground information” to assess if agricultural production estimates reflect growing conditions: prices and remote sensing data in the form of the normalized difference vegetation index (NDVI). The results show that existing production estimates are poorly correlated with both prices and the NDVI. Prices and the NDVI data are highly correlated, however. These findings imply that existing production estimates do not reflect growing conditions, and, therefore, are of poor quality. Chapter 3 is a comprehensive analysis of crop price transmission from global and neighbor country prices to Nigerian commercial hub and urban markets, and from commercial hubs to other urban and rural markets within the country. The results show that tradability matters for price transmission, but that tradability varies across crops and scopes of markets. Nigerian urban rice prices are highly correlated with prices on global markets and those in neighboring countries. Coarse grain prices appear disconnected from global markets, however, but move closely with those in neighboring countries. Large margins were estimated for prices of rice imported from global markets (in all regions), and for coarse grains to Southern Nigerian markets only. The existence of large margins implies that there are transactions costs and/or quality premiums that vary systematically with the world price, and/or mark-ups by traders with market power in these markets. While domestic market prices are almost always cointegrated, perfect price transmission is generally found only between commercial hubs and other urban markets. Moreover, long lags were found for price transmission across all scopes of markets, but especially between urban and rural prices in some regions. These results imply that local conditions (e.g., weather) are relatively more important than external market prices for explaining price variation in rural markets, especially in the short-run. Chapter 4 incorporates NDVI data into price formation models to estimate whether observable growing conditions explain price variation in Nigerian food security crop markets. Four issues related to use of NDVI data that exist within the literature are investigated: whether NDVI is a valid proxy for expected production, how NDVI is a proxy for seasonality, the relationship between market size and the area scope used to average NDVI values across space, and if anomalous harvest expectations can change long-run price variation and price relationships between markets. The results show that information on growing conditions is more informative for isolated than interconnected markets. Even for those local prices, however, other non-weather and non-external market price factors are relatively more important for explanation of price variation. An implication of these results is that Nigeria cannot plausibly rely solely on direct imports from global markets to meet short-run demand during future weather shock periods. Thus, storage is required to ensure stability of food security, either for imports or domestically produced surpluses acquired in non-crisis periods. Given the isolation of rural markets, local and on-farm stocks are at least as important as large facilities in commercial hubs. Improvement of village level and on-farm storage systems and elimination of other market distortions that inhibit trade between urban and rural markets would make public storage less needed. The findings on poor quality of agricultural statistics indicate a clear priority to improve agricultural data, to facilitate better planning of any food security strategies. A combination of surveys with remote sensed and crowd sourced data may improve feasibility in the funding constrained environment

Local molecular and global connectomic contributions to cross-disorder cortical abnormalities

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Cognitive outcome in adults with moderate disability after pneumococcal meningitis

Objectives To assess cognitive outcome and quality of life in patients with moderate disability after bacterial meningitis as compared to patients with good recovery. Methods Neuropsychological evaluation was performed in 40 adults after pneumococcal meningitis; 20 patients with moderate disability at discharge on the glasgow outcome scale (GOS score 4) and 20 with good recovery (GOS score 5). Results Patients with GOS score 4 had similar test results as compared to patients with GOS score 5 for the neuropsychological domains ‘intelligence’, ‘memory’ and ‘attention and executive functioning’. Patients with GOS score 4 showed less cognitive slowness than patients with GOS score 5. In a linear regression analysis cognitive speed was related to current intelligence, years of education and time since meningitis. Overall performance on the speed composite score correlated significantly with time since meningitis (−0.62; P<0.001). Therefore, difference between both groups may have been related to a longer time between meningitis and testing for GOS four patients (29 vs. 12 months; P<0.001). Conclusions Patients with moderate disability after bacterial meningitis are not at higher risk for neuropsychological abnormalities than patients with good recovery. In addition, cognitive slowness after bacterial meningitis may be reversible in time

The Composition of the Modernist Book: Ulysses, A Draft of XXX Cantos and The Making of Americans.

This is a study of the composition of three Modernist first editions: Ulysses (1922), The Making of Americans (1925) and A Draft of XXX Cantos (1930). The bibliographical and figurative commitments made to being in print by Ulysses, A Draft of XXX Cantos and The Making of Americans set a coherent program for reading Modernist texts in their perfected form: in print. The editorial reception of the Modernist book has proceeded, however, with reference to the editorial and bibliographical principles established by the New Bibliographers. In deferring to the authors and manuscripts of Modernist books as the highest source of textual authority, the vital significance of being in print to literary Modernism is obscured. The figure of the ideal Book concentrates the central aesthetic, intellectual and bibliographic problem posed the Modernist book: the making of literature. The rhyme with The Making of Americans is appropriate: this book intensifies and consolidates the propositions made about objective and autonomous composition made more hesitantly by Ulysses and A Draft of XXX Cantos. These three books display a gradual refusal to equate inscription and intention; their composition effaces all traces of a sovereign creative subjectivity. The vision of the book guides Modernist composition, and requires a critical distinction be drawn between manuscripts and printed letters. Modernism must be read in print. The vestigial nostalgia for Romantic modes of textual production and creation in Ulysses is repeated on the placards and proof-pages for the book. Printed drafts are revised and reformed by the pen of the author. The finality asserted by the printed letter is only reluctantly ceded on the publication of Ulysses. The composition of A Draft of XXX Cantos represents a further transition away from the script economy of Romanticism. The interplay between authorial typescripts, early publications and the first edition of A Draft of XXX Cantos assert an intermediate order of Modernist textuality which takes the printed page as its foundation. The Making of Americans relies on the absolute objectivity and anonymity of its composition for the effect of its narrative. Objectivity is the intellectual and aesthetic strategy which produces literature rather than the personality and memory of the author. The impersonality of the apparently automatically written manuscripts and scarcely revised typescripts for The Making of Americans severs the visible links between the writing author and her page. In their unwillingness to corroborate the modes of textual generation described by the New Bibliographers, these three books thematise their own composition as the exemplary Modernist and modern mode of textual generation. The Modernist book attenuates or denies a Romantic connection between the creative hand of the author and the surface image of the page: the mechanisms of print deliberately detach the author from the literary text. The distance of the author from the scene of textual reproduction is measured by the printed book. The composition of this analytical object is not a fallacy but an actuality, commemorated in the archive, enacted by the book. Modernism is the literature of the imprimatur rather than of authorial inscription and accordingly it is towards the first editions of Modernist texts that the attentions of editors and textual scholars must be directed

Disturbed corpus callosum microstructure in the presence of normal volume characterizes patients with adult ADHD

Background: Microstructural changes and volume reductions in the corpus callosum (CC) are implicated in childhood ADHD. There are however indications that, in adulthood ADHD, reduced white matter integrity is persistent whereas CC volume normalizes. Our goal was to investigate this in a relatively large adult ADHD sample. In addition to commonly used fractional anisotropy (FA) and mean diffusivity (MD), we calculated parallel (axial diffusion; AD) and perpendicular (radial diffusion; RD) diffusivities to white matter tracts which may offer additional information regarding tissue microstructure. Methods: White matter integrity and volume of the CC were investigated in 87 adult ADHD patients and 98 matched controls. We used diffusion tensor imaging in conjunction with tract-based spatial statistics to examine FA, MD, AD and RD within the genu, body and splenium of the CC. Volumetrics of the CC and its subdivisions were determined using FreeSurfer software. Results: The body of the CC showed lower FA (p = .005) and higher MD (p = .019) and RD (p = .008) values in ADHD patients, compared to controls. Volume of the CC did not differ between the groups (p = .633). Conclusions: Our findings show that callosal volume becomes normal while disturbed white matter integrity of the CC is persistent in adult ADHD. Abnormalities in the body of the CC, the subdivision that contains the commissural fibers connecting the somatosensory, auditory and motor areas may play an important role in the pathophysiology of ADHD

Dexamethasone and long-term outcome in adults with bacterial meningitis

This follow-up study of the European Dexamethasone Study was designed to examine the potential harmful effect of adjunctive dexamethasone treatment on long-term neuropsychological outcome in adults with bacterial meningitis. METHODS: Neurological, audiological, and neuropsychological examinations were performed in adults who survived pneumococcal or meningococcal meningitis. RESULTS: Eighty-seven of 99 (88%) eligible patients were included in the follow-up study; 46 (53%) were treated with dexamethasone and 41 (47%) with placebo. Median time between meningitis and testing was 99 months. Neuropsychological evaluation showed no significant differences between patients treated with dexamethasone and placebo. The proportions of patients with persisting neurological sequelae or hearing loss were similar in the dexamethasone and placebo groups. The overall rate of cognitive dysfunction did not differ significantly between patients and control subjects; however, patients after pneumococcal meningitis had a higher rate of cognitive dysfunction (21 vs 6%; p = 0.05) and experienced more impairment of everyday functioning due to physical problems (p = 0.05) than those after meningococcal meningitis. INTERPRETATION: Treatment with adjunctive dexamethasone is not associated with an increased risk for long-term cognitive impairment. Adults who survive pneumococcal meningitis are at significant risk for long-term neuropsychological abnormalities

Is synthetic hexaploid wheat a useful germplasm source for increasing grain size and yield in bread wheat breeding?

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An overview of the first 5 years of the ENIGMA obsessive–compulsive disorder working group: The power of worldwide collaboration

Abstract Neuroimaging has played an important part in advancing our understanding of the neurobiology of obsessive?compulsive disorder (OCD). At the same time, neuroimaging studies of OCD have had notable limitations, including reliance on relatively small samples. International collaborative efforts to increase statistical power by combining samples from across sites have been bolstered by the ENIGMA consortium; this provides specific technical expertise for conducting multi-site analyses, as well as access to a collaborative community of neuroimaging scientists. In this article, we outline the background to, development of, and initial findings from ENIGMA's OCD working group, which currently consists of 47 samples from 34 institutes in 15 countries on 5 continents, with a total sample of 2,323 OCD patients and 2,325 healthy controls. Initial work has focused on studies of cortical thickness and subcortical volumes, structural connectivity, and brain lateralization in children, adolescents and adults with OCD, also including the study on the commonalities and distinctions across different neurodevelopment disorders. Additional work is ongoing, employing machine learning techniques. Findings to date have contributed to the development of neurobiological models of OCD, have provided an important model of global scientific collaboration, and have had a number of clinical implications. Importantly, our work has shed new light on questions about whether structural and functional alterations found in OCD reflect neurodevelopmental changes, effects of the disease process, or medication impacts. We conclude with a summary of ongoing work by ENIGMA-OCD, and a consideration of future directions for neuroimaging research on OCD within and beyond ENIGMA

Pleiotropic contribution of MECOM and AVPR1A to aggression and subcortical brain volumes

Reactive and proactive subtypes of aggression have been recognized to help parse etiological heterogeneity of this complex phenotype. With a heritability of about 50%, genetic factors play a role in the development of aggressive behavior. Imaging studies implicate brain structures related to social behavior in aggression etiology, most notably the amygdala and striatum. This study aimed to gain more insight into the pathways from genetic risk factors for aggression to aggression phenotypes. To this end, we conducted genome-wide gene-based cross-trait meta-analyses of aggression with the volumes of amygdala, nucleus accumbens and caudate nucleus to identify genes influencing both aggression and aggression-related brain volumes. We used data of large-scale genome-wide association studies (GWAS) of: (a) aggressive behavior in children and adolescents (EAGLE, N = 18,988); and (b) Magnetic Resonance Imaging (MRI)-based volume measures of aggression-relevant subcortical brain regions (ENIGMA2, N = 13,171). Second, the identified genes were further investigated in a sample of healthy adults (mean age (SD) = 25.28 (4.62) years; 43% male) who had genome-wide genotyping data and questionnaire data on aggression subtypes available (Brain Imaging Genetics, BIG, N = 501) to study their effect on reactive and proactive subtypes of aggression. Our meta-analysis identified two genes, MECOM and AVPR1A, significantly associated with both aggression risk and nucleus accumbens (MECOM) and amygdala (AVPR1A) brain volume. Subsequent in-depth analysis of these genes in healthy adults (BIG), including sex as an interaction term in the model, revealed no significant subtype-specific gene-wide associations. Using cross-trait meta-analysis of brain measures and psychiatric phenotypes, this study generated new hypotheses about specific links between genes, the brain and behavior. Results indicate that MECOM and AVPR1A may exert an effect on aggression through mechanisms involving nucleus accumbens and amygdala volumes, respectively