Genetic diversity and population structure in Vitis species illustrate phylogeographic patterns in eastern North America.

Geographical distribution and diversity of current plant species have been strongly shaped by climatic oscillations during the Quaternary. Analysing the resulting divergence among species and differentiation within species is crucial to understand the evolution of taxa like the Vitis genus, which provides very useful genetic resources for grapevine improvement and might reveal original recolonization patterns due to growth habit and dispersal mode. Here, we studied the genetic structure in natural populations of three species from eastern North America: Vitis aestivalis, V. cinerea and V. riparia using different marker types. Vitis aestivalis and V. cinerea showed higher diversity than V. riparia. The two former species are less differentiated, confirming an earlier divergence of V. riparia. V. aestivalis and V. riparia exhibited different genetic groups on both sides of the Appalachian Mountains that could mirror different recolonization routes from southern refugia. Genetic structure was stronger in V. cinerea, for which two varieties (var. berlandieri and var. cinerea) are morphologically recognized. Our results confirm this distinction and suggest the existence of three other lineages within var. cinerea. These discontinuities appear linked to adaptation of var. berlandieri to dry and limy areas of Texas and partially to the Mississippi River Valley. Rapid range expansions from refugia upon climate warming are also suggested by the low linkage disequilibrium values observed. Furthermore, large variation for downy mildew resistance was observed in the three species. Our findings appeared consistent with the vegetation history of eastern North America.

Understanding the needs and experiences of people with young onset dementia: a qualitative study.

AIM: Despite an estimated 40 000 people diagnosed with young onset dementia (YOD) in the UK, there is a general lack of awareness of the condition when compared with late onset dementia. The aim of this study was to explore the experiences and needs of people living with YOD (younger than 65 years) and gain an understanding of the issues that impact on them. SETTING: Participants' homes, support group premises or university rooms. PARTICIPANTS: 14 people with a diagnosis of YOD from a northern UK city. DESIGN: Semistructured, in-depth interviews were audio recorded, transcribed and analysed cross-sectionally following principles of interpretative phenomenological analysis. RESULTS: Four superordinate themes are reported on 'process of diagnosis', 'the impact of living YOD', 'needs of people with YOD' and 'living well with YOD'. Nine subordinate themes captured participant experiences of developing cognitive difficulties, after being diagnosed with YOD, and subsequently living with the condition. Key issues that emerging included a lack of general awareness of YOD; how this can delay help seeking; commonalities in prediagnosis trajectories; retrospective understanding of prediagnosis symptom patterns; the difficulties of obtaining a firm diagnosis; the importance of face-to-face support and difficulties associated with daily living. Participants also described the emotional and psychological impact of the condition and the importance of formal and informal support networks. CONCLUSIONS: People who have a diagnosis of YOD regard themselves as distinct from older people with dementia. Despite similar symptoms, the context in which they experience the condition creates a range of distinct psychosocial concerns not commonly well addressed by health and social care services. As awareness of YOD continues to grow, the development (or adaptation) of services that take into account the idiosyncratic needs of people with YOD should be addressed.

Metabolic engineering of Pseudomonas putida for the utilization of parathion as a carbon and energy source.

Pseudomonas putida KT2442 was engineered to use the organophosphate pesticide parathion, a compound similar to other organophosphate pesticides and chemical warfare agents, as a source of carbon and energy. The initial step in the engineered degradation pathway was parathion hydrolysis by organophosphate hydrolase (OPH) to p-nitrophenol (PNP) and diethyl thiophosphate, compounds that cannot be metabolized by P. putida KT2442. The gene encoding the native OPH (opd), with and without the secretory leader sequence, was cloned into broad-host-range plasmids under the control of tac and taclac promoters. Expression of opd from the tac promoter resulted in high OPH activity, whereas expression from the taclac promoter resulted in low activity. A plasmid-harboring operons encoding enzymes for p-nitrophenol transformation to beta-ketoadipate was transformed into P. putida allowing the organism to use 0.5 mM PNP as a carbon and energy source. Transformation of P. putida with the plasmids harboring opd and the PNP operons allowed the organism to utilize 0.8 mM parathion as a source of carbon and energy. Degradation studies showed that parathion formed a separate dense, non-aqueous phase liquid phase but was still bioavailable.