This paper characterizes novel “star” defects in GaN films grown with metal–organic vapor phase deposition (MOVPE) on GaN substrates with electron channeling contrast imaging (ECCI) and high-resolution electron backscatter diffraction (HREBSD). These defects are hundreds of microns in size and tend to aggregate threading dislocations at their centers. They are the intersection of six nearly ideal low-angle tilt boundaries composed of $\langle a\rangle$-type pyramidal edge dislocations, each on a unique slip system.

Traditional ambulatory rhythm monitoring in children can have limitations, including cumbersome leads and limited monitoring duration. The ZioTM patch ambulatory monitor is a small, adhesive, single-channel rhythm monitor that can be worn up to 2 weeks. In this study, we present a retrospective cross-sectional analysis of the ZioTM monitor’s impact in clinical practice. Patients aged 0–18 years were included in the study. A total of 373 studies were reviewed in 332 patients. In all, 28.4% had structural heart disease, and 16.9% had a prior surgical, catheterisation, or electrophysiology procedure. The most common indication for monitoring was tachypalpitations (41%); 93.5% of these patients had their symptoms captured during the study window. The median duration of monitoring was 5 days. Overall, 5.1% of ZioTM monitoring identified arrhythmias requiring new intervention or increased medical management; 4.0% identified arrhythmias requiring increased clinical surveillance. The remainder had either normal-variant rhythm or minor rhythm findings requiring no change in management. For patients with tachypalpitations and no structural heart disease, 13.2% had pathological arrhythmias, but 72.9% had normal-variant rhythm during symptoms, allowing discharge from cardiology care. Notably, for patients with findings requiring intervention or increased surveillance, 56% had findings first identified beyond 24 hours, and only 62% were patient-triggered findings. Seven studies (1.9%) were associated with complications or patient intolerance. The ZioTM is a well-tolerated device that may improve what traditional Holter and event monitoring would detect in paediatric cardiology patients. This study shows a positive clinical impact on the management of patients within a paediatric cardiology practice.

The authors study the influence of domestic political dissent and violence on incumbent dictators and their regimes. They argue that elite with an interest in preserving the regime hold dictators accountable when there is a significant increase in terrorism. To pinpoint the accountability of dictators to elite who are strongly invested in the current regime, the authors make a novel theoretical distinction between reshuffling coups that change the leader but leave the regime intact and regime-change coups that completely change the set of elites atop the regime. Using a new data set that distinguishes between these two coup types, the authors provide robust evidence that terrorism is a consistent predictor of reshuffling coups, whereas forms of dissent that require broader public participation and support, such as protests and insurgencies, are associated with regime-change coup attempts. This article is the first to show that incumbent dictators are held accountable for terrorist campaigns that occur on their watch.

A key finding in the terrorism literature is that dictatorships experience less terrorism than democracies. However, we have few explanations for why some dictatorships experience substantial threats from terrorism while others do not. A growing body of work on authoritarian politics focuses on political institutions in these regimes to explain a broad range of political outcomes. Building on this literature, we argue that opposition political party activity increases the collective action capacity of regime opponents and that elected legislatures can channel this mobilized capacity into support for the government. However, when active opposition parties operate in the absence of legislatures, political opponents increasingly turn to terrorism. We find evidence that terrorist groups are most likely to emerge in dictatorships with opposition political parties but no elected legislature. These regimes also experience the highest volume of subsequent attacks.

New shell microstructure data for the Triassic pectinid Pleuronectites reinforce shell morphological data suggesting that its family Pectinidae was derived from the superfamily Aviculopectinoidea and not from the Pernopectinidae-Entolioidesidae-Entoliidae clade. This would make the superfamily Pectinoidea, as defined by recent authors, polyphyletic. This would also imply that alivincular-alate ligaments evolved independently in the Pernopectinidae-Entolioidesidae-Entolidae and Pectinidae clades.

The specimens of Gastrochaena cuneiformis Spengler, 1783, with Spengler-written labels at the Zoologisk Museum, Copenhagen, did not come from Spengler's type locality in the Nicobar Islands, and may instead be syntypes of Chemnitz's (1788) West Indies “Pholas hians”. the identity of Gastrochaena cuneiformis as a senior synonym of Gastrochaena gigantea (Deshayes, 1830) is established on the basis of Spengler's original descriptions and illustrations, and by examination of specimens from the type locality. A neotype for G. cuneiformis is designated and illustrated, and its genus is revised to exclude Rocellaria Blainville, 1829, and Lamychaena Freneix in Freneix and Roman, 1979. Gastrochaena Spengler, 1783 is the most plesiomorphic of these three genera, as shown by its simple boring, short siphons, and diffuse, poorly differentiated anterior pedal muscles. Rocellaria evolved from a close common ancestor with Gastrochaena, and is characterized by a ventral shift and fusion of the posteroventral pallial sinus with the posteroventral pallial band, low, irregular posterior commarginal lamellae, and well defined anterior pedal retractor muscles generally supported by myophores. Lamychaena evolved from Rocellaria during the Oligocene, extending its ctenidia far posterior into the siphonal part of the boring, and, in some species, uniting its anterior pedal retractor and protractor muscles as they approach the byssus apparatus.

Background. To evaluate the longitudinal course of psychiatric disorders in children of parents with panic disorder (PD) and major depression (MD) as they transition through the period of risk from childhood into adolescence.

Method. Over a 5-year follow-up, we compared psychiatric disorders in four groups of children: (1) offspring of parents with PD plus MD (n=136); (2) offspring of parents with PD without MD (n=27); (3) offspring of parents with MD but without PD (n=53); and (4) offspring of non-PD non-MD parents (n=103).

Results. Parental PD was significantly associated with increased risk for anxiety disorders, irrespective of parental MD. Parental MD was associated with increased risk for MD, disruptive behavior disorders, and deficits in psychosocial functioning, irrespective of parental PD.

Conclusions. These longitudinal findings confirm and extend previous cross-sectional results documenting significant associations between PD and MD in parents and patterns of psychopathology and dysfunction in their offspring.

We describe surface preparation and epilayer growth techniques that readily reduce the density of Vf drift inducing basal plane dislocations in epilayers to less than 10 cm-2 and permit the fabrication of bipolar SiC devices with very good Vf stability. The optimal process route requires etching the substrate surface prior to epilayer growth to enhance the natural conversion of basal plane dislocations into threading edge dislocations during epilayer growth. The surface of this relatively rough “conversion” epilayer is subsequently repolished prior to growing the device structure. We provide details on processing parameters and potential problems as well as describe devices produced using this low basal plane dislocation growth processes.