Fragments of the earliest land plants

The earliest fossil evidence for land plants comes from microscopic dispersed spores. These microfossils are abundant and widely distributed in sediments, and the earliest generally accepted reports are from rocks of mid-Ordovician age (Llanvirn, 475 million years ago). Although distribution, morphology and ultrastructure of the spores indicate that they are derived from terrestrial plants, possibly early relatives of the bryophytes, this interpretation remains controversial as there is little in the way of direct evidence for the parent plants. An additional complicating factor is that there is a significant hiatus between the appearance of the first dispersed spores and fossils of relatively complete land plants (megafossils): spores predate the earliest megafossils (Late Silurian, 425 million year ago) by some 50 million years. Here we report the description of spore-containing plant fragments from Ordovician rocks of Oman. These fossils provide direct evidence for the nature of the spore-producing plants. They confirm that the earliest spores developed in large numbers within sporangia, providing strong evidence that they are the fossilized remains of bona fide land plants. Furthermore, analysis of spore wall ultrastructure supports liverwort affinities

Review: The spectrum of clinical features seen with alpha synuclein pathology.

It has been recognized for many years that a number of chronic neurodegenerative diseases of the CNS are characterized by the development of intracellular inclusion bodies, but it is only relatively recently that the core proteins defining these pathologies have been defined. One such protein is alpha synuclein, that was found to be the main component of Lewy bodies in the late 1990s, and this discovery reinforced the emerging view that alpha synuclein was intimately linked to diseases characterized by this type of pathology--namely Parkinson's disease (PD) and Dementia with Lewy Bodies (DLB). Furthermore at around this time, this same protein was also found within the glial inclusion bodies of patients dying with multiple system atrophy (MSA). These three disorders constitute the majority of patients with an 'alpha synucleinopathy', although there are a number of rarer conditions that can also cause this pathology including inherited metabolic disorders such as Gaucher's disease (GD). In this review, we will concentrate on PD, the commonest alpha synucleinopathy, and its associated dementia (PDD), as well as discussing DLB and MSA and will highlight how the clinical features of these conditions vary as a function of pathology.Our own work on the natural history of Parkinson’s disease has been supported by the Wellcome Trust; MRC; Patrick Berthoud Trust; Cure Parkinson’s Trust; Parkinson’s UK and the Cambridge NIHR Biomedical Research Centre.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/nan.1230

Under one roof? A population-based survey of patient use and preference for sexual health services

To compare patterns of population service use and preference in areas with and without one-stop shop services. A number of strategy documents have recommended adopting a more integrated approach to sexual health service provision. One proposed model of integration is one-stop shops, where services for contraception and sexually transmitted infections are provided under the same roof. Currently, the potential impact of one-stop shop services on patient service use and preference is unclear, particularly at a population level. Three different models of one-stop shop were studied: a dedicated young persons’ service, a specialist mainstream service, and an enhanced general practice. In each model, the one-stop shop site was matched to two control sites with traditional service provision. Random samples of male and female patients were selected from general practices close to either the one-stop shop or control sites. These patients received a postal survey asking about their use or preference for services for six sexual health needs. One-stop shop and control samples were compared using multivariate logistic regression. Of the 14 387 patients surveyed, 3101 (21.6%) responded. In the young persons’ model, few significant differences were found in service use or preference between those living in one-stop shop and control site areas. In the specialist services model, women in the one-stop shop area were significantly more likely to cite specialist services for emergency contraception and abortion advice, when compared to those served by non-integrated control services. In the general practice model, respondents in the one-stop shop area were significantly more likely to cite general practice for all six sexual health needs. Overall, general practice was the preferred service provider cited for all sexual health needs, except condoms and pregnancy tests. These findings are discussed in terms of their implications for the provision of integrated sexual health services. In addition, key methodological issues and future research possibilities are identified. © 2009, Cambridge University Press. All rights reserved

Toll-like receptors and their therapeutic potential in Parkinson’s disease and α-synucleinopathies

Toll-like receptors (TLRs) are pattern recognition receptors which mediate an inflammatory response upon the detection of specific molecular patterns found on foreign organisms and on endogenous damage-related molecules. These receptors play a major role in the activation of microglia, the innate immune cells of the CNS, and are also expressed in peripheral tissues, including blood mononuclear cells and the gut. It is well established that immune activation, in both the brain and periphery, is a feature of Parkinson’s disease as well as other α-synucleinopathies. Aggregated forms of α-synuclein can act as ligands for TLRs (particularly TLR2 and TLR4), and hence these receptors may play a critical role in mediating a detrimental immune response to this protein, as well as other inflammatory signals in Parkinson’s and related α-synucleinopathies. In this review, the potential role of TLRs in contributing to the progression of these disorders is discussed. Existing evidence comes predominantly from studies in in vitro and in vivo models, as well as analyses of postmortem human brain tissue and pre-clinical studies of TLR inhibitors. This evidence is evaluated in detail, and the potential for therapeutic intervention in α-synucleinopathies through TLR inhibition is discussed.The authors are supported by the NIHR Cambridge Biomedical Research Centre Dementia Theme (146281) and the Rosetrees Trust (M369-F1). AK is supported by the Onassis Foundation and the Alborada Trust. CWG is funded by an MRC Clinician Scientist Fellowship (Grant: MR/R007446/1)

Progression of Neuropsychiatric Symptoms over Time in an Incident Parkinson's Disease Cohort (ICICLE-PD).

BACKGROUND: Cross-sectional studies have identified that the prevalence of neuropsychiatric symptoms (NPS) in Parkinson's disease (PD) ranges from 70-89%. However, there are few longitudinal studies determining the impact of NPS on quality of life (QoL) in PD patients and their caregivers. We seek to determine the progression of NPS in early PD. METHODS: Newly diagnosed idiopathic PD cases (n = 212) and age-matched controls (n = 99) were recruited into a longitudinal study. NPS were assessed using the Neuropsychiatric Inventory with Caregiver Distress scale (NPI-D). Further neuropsychological and clinical assessments were completed by participants, with reassessment at 18 and 36 months. Linear mixed-effects modelling determined factors associated with NPI-D and QoL over 36 months. RESULTS: Depression, anxiety, apathy and hallucinations were more frequent in PD than controls at all time points (p < 0.05). Higher motor severity at baseline was associated with worsening NPI-D scores over time (β = 0.1, p < 0.05), but not cognition. A higher NPI total score was associated with poorer QoL at any time point (β = 0.3, p < 0.001), but not changed in QoL scores. CONCLUSION: NPS are significantly associated with poorer QoL, even in early PD. Screening for NPS from diagnosis may allow efficient delivery of better support and treatment to patients and their families

On the accuracy of language trees

Historical linguistics aims at inferring the most likely language phylogenetic tree starting from information concerning the evolutionary relatedness of languages. The available information are typically lists of homologous (lexical, phonological, syntactic) features or characters for many different languages. From this perspective the reconstruction of language trees is an example of inverse problems: starting from present, incomplete and often noisy, information, one aims at inferring the most likely past evolutionary history. A fundamental issue in inverse problems is the evaluation of the inference made. A standard way of dealing with this question is to generate data with artificial models in order to have full access to the evolutionary process one is going to infer. This procedure presents an intrinsic limitation: when dealing with real data sets, one typically does not know which model of evolution is the most suitable for them. A possible way out is to compare algorithmic inference with expert classifications. This is the point of view we take here by conducting a thorough survey of the accuracy of reconstruction methods as compared with the Ethnologue expert classifications. We focus in particular on state-of-the-art distance-based methods for phylogeny reconstruction using worldwide linguistic databases. In order to assess the accuracy of the inferred trees we introduce and characterize two generalizations of standard definitions of distances between trees. Based on these scores we quantify the relative performances of the distance-based algorithms considered. Further we quantify how the completeness and the coverage of the available databases affect the accuracy of the reconstruction. Finally we draw some conclusions about where the accuracy of the reconstructions in historical linguistics stands and about the leading directions to improve it.Comment: 36 pages, 14 figure

The longer your work hours, the worse your relationship? The role of selective optimization with compensation in the associations of working time with relationship satisfaction and self-disclosure in dual-career couples

This two-wave panel study investigates the associations between working time, selective optimization with compensation in private life and relationship outcomes (i.e. relationship satisfaction and self-disclosure) in dual-career couples. We propose that one partner’s selective optimization with compensation in private life either mediates or moderates the association of this partner’s working time and relationship outcomes (i.e. relationship satisfaction and self-disclosure). Moreover, we postulate the crossover (i.e. transmission) of relationship satisfaction and self-disclosure within the couple. To test these hypotheses, we conducted an online study with a time lag of six months, in which 285 dual-career couples took part. We found evidence for selective optimization with compensation in private life as a mediator: working time spent by partners in dual-career couples was associated with selective optimization with compensation in their private life that, in turn, predicted relationship satisfaction and self-disclosure. Results did not support the assumption that one partner’s selective optimization with compensation in private life moderates the association between working time and relationship satisfaction and self-disclosure. Relationship satisfaction, but not self-disclosure, crossed over within the couples. The results challenge the assumption that longer work hours have negative consequences for romantic relationships

Influence of vortex-vortex interaction on critical currents across low-angle grain boundaries in YBa2Cu3O7-delta thin films

Low-angle grain boundaries with misorientation angles theta < 5 degrees in optimally doped thin films of YBCO are investigated by magnetooptical imaging. By using a numerical inversion scheme of Biot-Savart's law the critical current density across the grain boundary can be determined with a spatial resolution of about 5 micrometers. Detailed investigation of the spatially resolved flux density and current density data shows that the current density across the boundary varies with varying local flux density. Combining the corresponding flux and current pattern it is found that there exists a universal dependency of the grain boundary current on the local flux density. A change in the local flux density means a variation in the flux line-flux line distance. With this knowledge a model is developped that explains the flux-current relation by means of magnetic vortex-vortex interaction.Comment: 7 pages, 14 figure

Anomalous Proximity Effect in Underdoped YBaCuO Josephson Junctions

Josephson junctions were photogenerated in underdoped thin films of the YBa$_2$Cu$_3$O$_{6+x}$ family using a near-field scanning optical microscope. The observation of the Josephson effect for separations as large as 100 nm between two wires indicates the existence of an anomalously large proximity effect and show that the underdoped insulating material in the gap of the junction is readily perturbed into the superconducting state. The critical current of the junctions was found to be consistent with the conventional Josephson relationship. This result constrains the applicability of SO(5) theory to explain the phase diagram of high critical temperature superconductors.Comment: 11 pages, 4 figure