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The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
Substantial clinical heterogeneity of major depressive disorder (MDD) suggests it may group together individuals with diverse aetiologies. Identifying distinct subtypes should lead to more effective diagnosis and treatment, while providing more useful targets for further research. Genetic and clinical overlap between MDD and schizophrenia (SCZ) suggests an MDD subtype may share underlying mechanisms with SCZ.
The present study investigated whether a neurobiologically distinct subtype of MDD could be identified by SCZ polygenic risk score (PRS). We explored interactive effects between SCZ PRS and MDD case/control status on a range of cortical, subcortical and white matter metrics among 2370 male and 2574 female UK Biobank participants.
There was a significant SCZ PRS by MDD interaction for rostral anterior cingulate cortex (RACC) thickness (β = 0.191, q = 0.043). This was driven by a positive association between SCZ PRS and RACC thickness among MDD cases (β = 0.098, p = 0.026), compared to a negative association among controls (β = −0.087, p = 0.002). MDD cases with low SCZ PRS showed thinner RACC, although the opposite difference for high-SCZ-PRS cases was not significant. There were nominal interactions for other brain metrics, but none remained significant after correcting for multiple comparisons.
Our significant results indicate that MDD case-control differences in RACC thickness vary as a function of SCZ PRS. Although this was not the case for most other brain measures assessed, our specific findings still provide some further evidence that MDD in the presence of high genetic risk for SCZ is subtly neurobiologically distinct from MDD in general.
Chromosome 22q11.2 deletion syndrome (22q11DS) is associated with high rates of psychiatric disorders, including schizophrenia in up to 30% of individuals with the syndrome. Despite this, we know relatively little about trajectories and predictors of persistence of psychiatric disorders from middle childhood to early adulthood. Accordingly, we followed youth over four timepoints, every 3 years, to assess long-term trajectories of attention-deficit hyperactivity disorder (ADHD), anxiety, mood, and psychosis-spectrum disorders (PSDs), as well as medication usage.
Eighty-seven youth with 22q11DS and 65 controls between the ages of 9 and 15 years at the first timepoint (T1; mean age 11.88 ± 2.1) were followed for 9 years (mean age of 21.22 ± 2.01 years at T4). Baseline cognitive, clinical, and familial predictors of persistence were identified for each class of psychiatric disorders.
Baseline age and parent-rated hyperactivity scores predicted ADHD persistence [area under curve (AUC) = 0.81]. The presence of family conflict predicted persistence of anxiety disorders (ADs) whereas parent ratings of child internalizing symptoms predicted persistence of both anxiety and mood disorders (MDs) (AUC = 0.84 and 0.83, respectively). Baseline prodromal symptoms predicted persistent and emergent PSDs (AUC = 0.83). Parent-reported use of anti-depressants/anxiolytics increased significantly from T1 to T4.
Psychiatric, behavioral, and cognitive functioning during late childhood and early adolescence successfully predicted children with 22q11DS who were at highest risk for persistent psychiatric illness in young adulthood. These findings emphasize the critical importance of early assessments and interventions in youth with 22q11DS.
Late Quaternary reflooding of the Persian Gulf climaxed with the mid-Holocene highstand previously variously dated between 6 and 3.4 ka. Examination of the stratigraphic and paleoenvironmental context of a mid-Holocene whale beaching allows us to accurately constrain the timing of the transgressive, highstand and regressive phases of the mid- to late Holocene sea-level highstand in the Persian Gulf. Mid-Holocene transgression of the Gulf surpassed today's sea level by 7100–6890 cal yr BP, attaining a highstand of > 1 m above current sea level shortly after 5290–4570 cal yr BP before falling back to current levels by 1440–1170 cal yr BP. The cetacean beached into an intertidal hardground pond during the transgressive phase (5300–4960 cal yr BP) with continued transgression interring the skeleton in shallow-subtidal sediments. Subsequent relative sea-level fall produced a forced regression with consequent progradation of the coastal system. These new ages refine previously reported timings for the mid- to late Holocene sea-level highstand published for other regions. By so doing, they allow us to constrain the timing of this correlatable global eustatic event more accurately.
Volcanic eruptions commonly produce buoyant ash-laden plumes that rise through the stratified atmosphere. On reaching their level of neutral buoyancy, these plumes cease rising and transition to horizontally spreading intrusions. Such intrusions occur widely in density-stratified fluid environments, and in this paper we develop a shallow-layer model that governs their motion. We couple this dynamical model to a model for particle transport and sedimentation, to predict both the time-dependent distribution of ash within volcanic intrusions and the flux of ash that falls towards the ground. In an otherwise quiescent atmosphere, the intrusions spread axisymmetrically. We find that the buoyancy-inertial scalings previously identified for continuously supplied axisymmetric intrusions are not realised by solutions of the governing equations. By calculating asymptotic solutions to our model we show that the flow is not self-similar, but is instead time-dependent only in a narrow region at the front of the intrusion. This non-self-similar behaviour results in the radius of the intrusion growing with time
, rather than
as suggested previously. We also identify a transition to drag-dominated flow, which is described by a similarity solution with radial growth now proportional to
. In the presence of an ambient wind, intrusions are not axisymmetric. Instead, they are predominantly advected downstream, while at the same time spreading laterally and thinning vertically due to persistent buoyancy forces. We show that close to the source, this lateral spreading is in a buoyancy-inertial regime, whereas far downwind, the horizontal buoyancy forces that drive the spreading are balanced by drag. Our results emphasise the important role of buoyancy-driven spreading, even at large distances from the source, in the formation of the flowing thin horizontally extensive layers of ash that form in the atmosphere as a result of volcanic eruptions.
Hospital evacuations that occur during, or as a result of, infrastructure outages are complicated and demanding. Loss of infrastructure services can initiate a chain of events with corresponding management challenges. This report describes a modeling case study of the 2001 evacuation of the Memorial Hermann Hospital in Houston, Texas (USA). The study uses a model designed to track such cascading events following loss of infrastructure services and to identify the staff, resources, and operational adaptations required to sustain patient care and/or conduct an evacuation. The model is based on the assumption that a hospital’s primary mission is to provide necessary medical care to all of its patients, even when critical infrastructure services to the hospital and surrounding areas are disrupted. Model logic evaluates the hospital’s ability to provide an adequate level of care for all of its patients throughout a period of disruption. If hospital resources are insufficient to provide such care, the model recommends an evacuation. Model features also provide information to support evacuation and resource allocation decisions for optimizing care over the entire population of patients. This report documents the application of the model to a scenario designed to resemble the 2001 evacuation of the Memorial Hermann Hospital, demonstrating the model’s ability to recreate the timeline of an actual evacuation. The model is also applied to scenarios demonstrating how its output can inform evacuation planning activities and timing.
VugrinED, VerziSJ, FinleyPD, TurnquistMA, GriffinAR, RicciKA, Wyte-LakeT. Modeling Evacuation of a Hospital without Electric Power. Prehosp Disaster Med. 2015;30(3):1-9
The Stanford Prison Experiment (SPE) is widely recognized as one of the most ethically controversial psychology studies ever conducted. In 1971, 24 college students who had volunteered to take part in a “psychological study of prison life” were randomly assigned to roles as guards and prisoners within a “prison” that had been specially constructed in the basement of the Stanford University psychology department. As most psychology students would be aware, the study had to be brought to a premature close after six days due to the intense distress that the prisoners were experiencing at the hand of the guards. At the time, the ethical framework for conducting research of this form was poorly defined and relatively informal. But partly as a consequence of the horrors it led to, after the SPE, psychologists’ code of research ethics was formalized and tightened, with the result that many felt it would never again be possible to conduct studies of this form.
Despite – or perhaps because of – this, since it was conducted, the SPE has exerted a vice-like grip over discussions about the issues of tyranny and evil that it investigated. This means that when reflecting on large-scale human atrocity, it is commonplace for researchers and commentators alike to reprise the argument that this reflects people’s “natural” tendency to conform uncritically to the specifications of any group roles they are assigned, however noxious they might be. This in itself is of major ethical concern, potentially letting perpetrators off the hook. Thus, if conducting studies like the SPE raises serious ethical issues, not conducting them is equally of ethical concern.