Accumulation of potassium in grapevine rootstocks (Vitis) grafted to ‘Shiraz’ as affected by growth, root-traits and transpiration

The concentration of potassium (K) in scions can be controlled by rootstocks (Vitis). However, differences between rootstocks in the accumulation of K and mechanisms of regulation of K, when rootstocks are grafted to a scion, are not clearly understood. Therefore, the current study addresses these issues. Rootstocks Freedom, Schwarzmann, Ramsey, 1103 Paulsen, 110 Richter, 140 Ruggeri and 101-14 were grafted with ‘Shiraz’ and grown in sand for 56 days in a glasshouse, with daily watering using solutions containing 3 mM K. At day 56, Freedom had highest total K uptake. Freedom and 101-14 had the highest and 140 Ruggeri the lowest concentration of K respectively, in shoot and roots. Accumulation of K in grapevine is affected by the interaction between rootstock and scion, with total K uptake increasing with total root length, total root surface area and percentage of roots in small diameter class (< 0.5 mm). Accumulation of K in the whole grapevine or in the shoot was not affected by either shoot/roots dry weight or transpiration, but was positively related to concentration of K (but not Na) in xylem. The current study highlights the positive impact of root based factors, specifically root traits and root pressure than other (e.g. shoot/roots dry weight, transpiration) in the accumulation of K in ‘Shiraz’ grapevines when assessed as grafted vines on a range of rootstocks. This knowledge will be important in selecting the new rootstocks for appropriate K uptake or accumulation.

Uptake, transport, accumulation and retranslocation of potassium in grapevine rootstocks (Vitis)

The concentration and content of potassium (K) within grapevine can be regulated by selective use of rootstocks. However, the mechanisms by which rootstocks differ in the accumulation of K in the shoot of grapevine are not well understood. Therefore, the current study addresses these issues. Ungrafted rootstocks 140 Ruggeri (140 R) and 101-14 Millardet de Grasset (101-14) were exposed to K tracer rubidium (Rb) in a glasshouse, for 4 hours through roots to study uptake and transport of Rb from roots to shoot, and for 24 hours through leaf to study downward transport of Rb, in each case assessed up to 48 hours following exposure to Rb. Transpiration rates and root traits were also measured. Results showed similar total Rb uptake and similar downward transport of Rb between the two rootstocks but lower accumulation of Rb in the shoot and lower shoot/roots Rb concentration (as a result of higher retention of Rb in roots), in 140 R than that in 101-14. Transpiration rates and total root length (but not total root surface area) remained similar between two rootstocks. The study shows that short term differences in the accumulation of K in roots and shoot between rootstocks are due to differences in the transport of K from roots to the shoot, rather than by differences in net uptake or retranslocation of K. In addition, such differences were not affected by transpiration rates. The results highlight that accumulation of K in shoot of grapevine rootstocks is regulated mainly by roots

Uptake, transport, accumulation and retranslocation of potassium in grapevine rootstocks (Vitis)

The concentration and content of potassium (K) within grapevine can be regulated by selective use of rootstocks. However, the mechanisms by which rootstocks differ in the accumulation of K in the shoot of grapevine are not well understood. Therefore, the current study addresses these issues. Ungrafted rootstocks 140 Ruggeri (140 R) and 101-14 Millardet de Grasset (101-14) were exposed to K tracer rubidium (Rb) in a glasshouse, for 4 hours through roots to study uptake and transport of Rb from roots to shoot, and for 24 hours through leaf to study downward transport of Rb, in each case assessed up to 48 hours following exposure to Rb. Transpiration rates and root traits were also measured. Results showed similar total Rb uptake and similar downward transport of Rb between the two rootstocks but lower accumulation of Rb in the shoot and lower shoot/roots Rb concentration (as a result of higher retention of Rb in roots), in 140 R than that in 101-14. Transpiration rates and total root length (but not total root surface area) remained similar between two rootstocks. The study shows that short term differences in the accumulation of K in roots and shoot between rootstocks are due to differences in the transport of K from roots to the shoot, rather than by differences in net uptake or retranslocation of K. In addition, such differences were not affected by transpiration rates. The results highlight that accumulation of K in shoot of grapevine rootstocks is regulated mainly by roots. Key words: Cation, nutrient, root, shoot, translocation, transpiration

Regulation of berry quality parameters in 'Shiraz' grapevines through rootstocks (Vitis)

The concentration of potassium (K) and pH in juice of grapevines is influenced by rootstocks (Vitis). However, the performance of rootstocks with respect to berry quality parameters and inter-relationships among berry quality parameters are not well understood. The current study addresses these issues. Berry and leaf samples at harvest maturity were collected from mature field-grown 'Shiraz' grapevines grafted with each of the rootstocks Dogridge, Freedom, Ramsey, 1103 Paulsen and 140 Ruggeri. Concentrations of K in juice and petiole and pH in juice were each highest for Dogridge and Freedom, but lowest for 140 Ruggeri and 1103 Paulsen. High concentration of K in juice was related to high concentrations of malic acid and TSS but low tartaric acid/malic acid ratio. In this study, lower concentrations of K in juice and in turn pH in juice of 'Shiraz' grapevines were maintained through rootstocks such as 140 Ruggeri and 1103 Paulsen that also show lower concentrations of K in petiole and TSS in juice, and higher tartaric/malic acid concentration ratio in juice at maturity. Selective use of these rootstocks in turn helps to produce quality grape juice and wine.

Brain–Machine Interfaces: The Role of the Neurosurgeon

The neurotechnology field is set to expand rapidly in the coming years as technological innovations in hardware and software are translated to the clinical setting. Given our unique access to patients with neurological disorders, expertise with which to guide appropriate treatments and technical skills to implant brain-machine interfaces (BMIs), neurosurgeons have a key role to play in the progress of this field. We outline the current state and key challenges in this rapidly advancing field including implant technology, implant recipients, implantation methodology, implant function, ethical, regulatory and economic considerations. Our key message is to encourage the neurosurgical community to proactively engage in collaborating with other healthcare professionals, engineers, scientists, ethicists and regulators in tackling these issues. By doing so, we will equip ourselves with the skills and expertise to drive the field forward and avoid being mere technicians in an industry driven by those around us

Planning stereoelectroencephalography using automated lesion detection: Retrospective feasibility study

OBJECTIVE: This retrospective, cross-sectional study evaluated the feasibility and potential benefits of incorporating deep-learning on structural magnetic resonance imaging (MRI) into planning stereoelectroencephalography (sEEG) implantation in pediatric patients with diagnostically complex drug-resistant epilepsy. This study aimed to assess the degree of colocalization between automated lesion detection and the seizure onset zone (SOZ) as assessed by sEEG. METHODS: A neural network classifier was applied to cortical features from MRI data from three cohorts. (1) The network was trained and cross-validated using 34 patients with visible focal cortical dysplasias (FCDs). (2) Specificity was assessed in 20 pediatric healthy controls. (3) Feasibility of incorporation into sEEG implantation plans was evaluated in 34 sEEG patients. Coordinates of sEEG contacts were coregistered with classifier-predicted lesions. sEEG contacts in seizure onset and irritative tissue were identified by clinical neurophysiologists. A distance of <10 mm between SOZ contacts and classifier-predicted lesions was considered colocalization. RESULTS: In patients with radiologically defined lesions, classifier sensitivity was 74% (25/34 lesions detected). No clusters were detected in the controls (specificity = 100%). Of the total 34 sEEG patients, 21 patients had a focal cortical SOZ, of whom eight were histopathologically confirmed as having an FCD. The algorithm correctly detected seven of eight of these FCDs (86%). In patients with histopathologically heterogeneous focal cortical lesions, there was colocalization between classifier output and SOZ contacts in 62%. In three patients, the electroclinical profile was indicative of focal epilepsy, but no SOZ was localized on sEEG. In these patients, the classifier identified additional abnormalities that had not been implanted. SIGNIFICANCE: There was a high degree of colocalization between automated lesion detection and sEEG. We have created a framework for incorporation of deep-learning-based MRI lesion detection into sEEG implantation planning. Our findings support the prospective evaluation of automated MRI analysis to plan optimal electrode trajectories

Challenging undue influence?:Rethinking children’s participation in contested child contact

Despite the widespread ratification of the United Nations Convention on the Rights of the Child, children continue to struggle to have their participation rights recognised and supported. This is evident within family law, where despite sometimes progressive and strong legislation, children’s views are often not heard, nor given due weight, when parent-child contact is contested within the courts. This paper explores barriers to children’s participation rights being realised. It uses Scotland as the example, due to its strong legal safeguards and mechanisms that aim to support participation rights. The paper draws on recent empirical research with legal professionals, combined with an analysis of reported case law and relevant literature, to explore the barriers ‘on the ground’ for children’s participation rights. Through our analysis, we offer new ways to conceptualise the notion of influence in children’s participation rights in family actions. We offer the conceptual devices of ‘the influenced child’ and ‘the influential child’ to elucidate how children’s participation rights are restricted

Drug-resistant focal epilepsy in children is associated with increased modal controllability of the whole brain and epileptogenic regions

Network control theory provides a framework by which neurophysiological dynamics of the brain can be modelled as a function of the structural connectome constructed from diffusion MRI. Average controllability describes the ability of a region to drive the brain to easy-to-reach neurophysiological states whilst modal controllability describes the ability of a region to drive the brain to difficult-to-reach states. In this study, we identify increases in mean average and modal controllability in children with drug-resistant epilepsy compared to healthy controls. Using simulations, we purport that these changes may be a result of increased thalamocortical connectivity. At the node level, we demonstrate decreased modal controllability in the thalamus and posterior cingulate regions. In those undergoing resective surgery, we also demonstrate increased modal controllability of the resected parcels, a finding specific to patients who were rendered seizure free following surgery. Changes in controllability are a manifestation of brain network dysfunction in epilepsy and may be a useful construct to understand the pathophysiology of this archetypical network disease. Understanding the mechanisms underlying these controllability changes may also facilitate the design of network-focussed interventions that seek to normalise network structure and function