The tropics contain the overwhelming majority of Earth's biodiversity: their terrestrial, freshwater and marine ecosystems hold more than three-quarters of all species, including almost all ...shallow-water corals and over 90% of terrestrial birds. However, tropical ecosystems are also subject to pervasive and interacting stressors, such as deforestation, overfishing and climate change, and they are set within a socio-economic context that includes growing pressure from an increasingly globalized world, larger and more affluent tropical populations, and weak governance and response capacities. Concerted local, national and international actions are urgently required to prevent a collapse of tropical biodiversity.
There is sufficient evidence that the pathological process that causes Parkinson’s disease begins years before the clinical diagnosis is made. Over the last 15 years, there has been much interest in ...the existence of a prodrome in some patients, with a particular focus on non-motor symptoms such as reduced sense of smell, REM-sleep disorder, depression, and constipation. Given that the diagnostic criteria for Parkinson’s disease depends on the presence of bradykinesia, it is somewhat surprising that there has been much less research into the possibility of subtle motor dysfunction as a pre-diagnostic pointer. This review will focus on early motor features and provide some advice on how to detect and measure them.
Although low-dimensional S = 1 antiferromagnets remain of great interest, difficulty in obtaining high-quality single crystals of the newest materials hinders experimental research in this area. ...Polycrystalline samples are more readily produced, but there are inherent problems in extracting the magnetic properties of anisotropic systems from powder data. Following a discussion of the effect of powder-averaging on various measurement techniques, we present a methodology to overcome this issue using thermodynamic measurements. In particular we focus on whether it is possible to characterise the magnetic properties of polycrystalline, anisotropic samples using readily available laboratory equipment. We test the efficacy of our method using the magnets Ni(H2O)2(3,5-lutidine)4(BF4)2 and Ni(H2O)2(acetate)2(4-picoline)2, which have negligible exchange interactions, as well as the antiferromagnet Ni(H2O)2(pyrazine)2(BF4)2, and show that we are able to extract the anisotropy parameters in each case. The results obtained from the thermodynamic measurements are checked against electron-spin resonance and neutron diffraction. We also present a density functional method, which incorporates spin-orbit coupling to estimate the size of the anisotropy in Ni(H2O)2(pyrazine)2(BF4)2.
Andrew Lees looks back at the writings of Gabriel García Márquez, and considers what works such as One Hundred Years of Solitude and The Autumn of the Patriarch can teach us about memory and about ...the disadvantages – but also the benefits – of forgetting.
We have carried out a systematic review of the case files of 242 donors with pathologically verified Parkinson's disease at the Queen Square Brain Bank for Neurological Disorders in an attempt to ...corroborate the data-driven subtype classification proposed by Lewis and colleagues (Heterogeneity of Parkinson's disease in the early clinical stages using a data driven approach. J Neurol Neurosurg Psychiatry 2005; 76: 343–8). Cases were segregated into earlier disease onset (25%), tremor dominant (31%), non-tremor dominant (36%) and rapid disease progression without dementia (8%) subgroups. We found a strong association between a non-tremor dominant disease pattern and cognitive disability. The earlier disease onset group had the longest duration to death, and greatest delay to the onset of falls and cognitive decline. Patients with a tremor dominant disease pattern did not live significantly longer than non-tremor dominant patients and showed no difference in mean time to onset of falls and hallucinations. Rapid disease progression was associated with older age, early depression and early midline motor symptoms, and in 70% of the cases, tremulous onset. The non-tremor dominant subgroup had a significantly higher mean pathological grading of cortical Lewy bodies than all other groupings (P < 0.05) and more cortical amyloid-β plaque load and cerebral amyloid angiopathy than early disease onset and tremor dominant groups (P = 0.047). An analysis of cases with pathologically defined neocortical Lewy body disease confirmed the link between bradykinetic onset, cognitive decline and Lewy body deposition in the neocortex. Although neuropathological examination failed to distinguish the other subtypes, the classification scheme was supported by an analysis of clinical data that were independent of the basic subgroup definitions.
Ten-year follow-up results from the Parkinson's Disease Research Group of the United Kingdom trial demonstrated that there were no long-term advantages to initiating treatment with bromocriptine ...compared with l-dopa in early Parkinson disease (PD). Increased mortality in patients on selegiline combined with l-dopa led to premature termination of this arm after 6 years.
Between 1985 and 1990, 782 patients were recruited into an open pragmatic multicenter trial and were randomized to l-dopa/decarboxylase inhibitor (DDCI), l-dopa/DDCI plus selegiline, or bromocriptine. The main endpoints were mortality, disability, and motor complications. For final follow-up, health-related quality of life and mental function were also assessed.
Median duration of follow-up at final assessment was 14 years in the 166 (21%) surviving participants who could be contacted. After adjustment for baseline characteristics, disability scores were better in the l-dopa than in the bromocriptine arm (Webster: 16.6 vs 19.8; p = 0.03; Northwestern University Disability: 34.3 vs 30.0, p = 0.05). Physical functioning (difference 20.8; 95% CI 10.0, 31.6; p < 0.001) and physical summary scores (difference 5.2; 95% CI 0.7, 9.7; p = 0.03) on the 36-item short-form health survey were also superior on l-dopa. Differences in mortality rates and prevalence of dyskinesias, motor fluctuations, and dementia were not significantly different.
Initial treatment with the dopamine agonist bromocriptine did not reduce mortality or motor disability and the initially reduced frequency in motor complications was not sustained. We found no evidence of a long-term benefit or clinically relevant disease-modifying effect with initial dopamine agonist treatment.
Although it is clear that microtubule associated protein tau (MAPT) is involved in Alzheimer's disease (AD) pathology, it has not been clear whether it is involved genetically. We have recently ...examined the MAPT locus in progressive supranuclear palsy and found that a haplotype (H1c) on the background of the well-described H1 clade is associated with PSP. Here we report that the same haplotype is associated with the risk of AD in two autopsy confirmed series of cases with ages at death >65 years.
Bird watching on the asphalt Lees, A J
Brain (London, England : 1878),
02/2021, Letnik:
144, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Attempting to make a diagnosis from a collection of baffling symptoms is comparable to the challenge of identifying an unusual bird that refuses to stay still. Andrew Lees describes how bird watching ...and a love of natural history helped turn him not only into a noticer, but ultimately into a neurologist.
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