Adding rotation to translation: percepts and illusions

This study investigated how the perception of a translating object is affected by rotation. Observers were asked to judge the motion and trajectory of objects that rotated around their centroid while linearly translating. The expected percept, consistent with the actual dynamics used to generate the movie sequences, is that of a translating and rotating object, akin to a tumbling rugby ball. Observers, however, do not always report this and, under certain circumstances, perceive the object to translate on an illusory curved trajectory, similar to a car driving on a curved road. The prevalence of veridical versus nonveridical percepts depends on a number of factors. First, if the object's orientation remains within a limited range relative to the axis of translation, the illusory, curved percept dominates. If the orientation, at any point of the movie sequence, differs sufficiently from the axis of translation, the percept switches to linear translation with rotation. The angle at which the switch occurs is dependent upon a number of factors that relate to an object's elongation and, with it, the prominence of its orientation. For an ellipse with an aspect ratio of 3, the switch occurs at approximately 45°. Higher aspect ratios increase the range; lower ratios decrease it. This applies similarly to rectangular shapes. A line is more likely to be perceived on a curved trajectory than an elongated rectangle, which, in turn, is more likely seen on a curved path than a square. This is largely independent of rotational and translational speeds. Measuring perceived directions of motion at different instants in time allows the shape of the perceived illusory curved path to be extrapolated. This results in a trajectory that is independent of object size and corresponds closely to the actual object orientation at different points during the movie sequence. The results provide evidence for a perceptual transition from an illusory curved trajectory to a veridical linear trajectory (with rotation) for the same object. Both are consistent with special real-world cases such as objects rotating around a centre outside of the object so that their orientation remains tangent to the trajectory (cheetahs running along a curve, sailboats) or objects tumbling along simple trajectories (a monkey spinning in air, spinning cars on ice). In certain cases, the former is an illusion. </jats:p

Patients' and relatives' assessment of clozapine treatment

Published version: http://journals.cambridge.org/action/displayJournal?jid=PS

Microtopographic refuges enhance recruitment and survival, but inhibit growth of propagules of the tropical macroalga Sargassum swartzii

For organisms with discrete life-histories, any mechanism that enhances growth and/or survival at critical life-history transitions may significantly influence adult population size. On coral reefs, structurally complex microhabitats enhance the early post-settlement growth and/or survival of fishes and corals; however, the importance of such microhabitats to the early life stages of tropical macroalgae is largely unknown. Here, we investigate the effect of crevices on the recruitment, growth and survival of propagules of a common coral reef macroalga, Sargassum swartzii. We settled S. swartzii propagules onto terracotta settlement tiles that had a series of 3 mm deep crevices evenly spaced on their top (exposed) surface. Recruitment of S. swartzii was 21% greater, but propagules were 18% shorter, 18-days post-settlement within crevices than on adjacent exposed surfaces. Exposing tiles to local fish assemblages for five days showed that survival of propagules was 90% greater in crevices than on exposed areas of the tiles on the reef crest, but not on the reef flat. Underwater video footage revealed that few fishes fed from within the crevices (18% of all bites) with the majority of feeding being concentrated on the exposed surface of tiles. Interestingly, small-bodied fishes from the family Blenniidae (predominantly Ecsenius spp.) accounted for the majority of the feeding activity on the tiles, and likely contributed to the mortality of propagules. Structurally complex microhabitats, such as crevices, that shelter vulnerable early post-settlement propagules from herbivory may therefore be important for the persistence of macroalgae on coral reefs

Circle talks as situated experiential learning: Context, identity, and knowledgeability in \u27learning from reflection\u27

This article presents research that used ethnographic and sociolinguistic methods to study ways participants learn through reflection when carried out as a “circle talk.” The data indicate that participants in the event (a) invoked different contextual frames that (b) implicated them in various identity positions, which (c) affected how they could express their knowledge. These features worked together to generate socially shared meanings that enabled participants to jointly achieve conceptualization—the ideational role “reflection” is presumed to play in the experiential learning process. The analysis supports the claim that participants generate new knowledge in reflection, but challenges individualistic and cognitive assumptions regarding how this occurs. The article builds on situated views of experiential learning by showing how knowledge can be understood as socially shared and how learning and identity formation are mutually entailing processes

Agriculture Beyond Food: Experiences from Indonesia

The ABF programme addresses one of today’s major societal challenges, how to achieve a sustainable and inclusive biobased economy, with high-level scientific research on the thin lines between food and non-food, commodities and waste products, livelihood opportunities and risks, and local and global economy. This book provides insights into the main issues and key questions relating to the biobased economy, reflects on the objectives of the ABF programme, and offers policy recommendations. It summarises the projects conducted within the three major clusters at the heart of the programme: migration and forest transformation, breakthroughs in biofuel production technology, and the commoditisation of an alternative biofuel crop. The book ends with a number of lessons learned from the ABF programme on interdisciplinary programming

Cavity induced modifications to the resonance fluorescence and probe absorption of a laser-dressed V atom

A cavity-modified master equation is derived for a coherently driven, V-type three-level atom coupled to a single-mode cavity in the bad cavity limit. We show that population inversion in both the bare and dressed-state bases may be achieved, originating from the enhancement of the atom-cavity interaction when the cavity is resonant with an atomic dressed-state transition. The atomic populations in the dressed state representation are analysed in terms of the cavity-modified transition rates. The atomic fluorescence spectrum and probe absorption spectrum also investigated, and it is found that the spectral profiles may be controlled by adjusting the cavity frequency. Peak suppression and line narrowing occur under appropriate conditions.Comment: 12 pages, 10 postscript figures, to be appeared in Phys. Rev.

Conditional inactivation of the Men1 gene leads to pancreatic and pituitary tumorigenesis but does not affect normal development of these tissues

Mutations of the MEN1 gene, encoding the tumor suppressor menin, predispose individuals to the cancer syndrome multiple endocrine neoplasia type 1, characterized by the development of tumors of the endocrine pancreas and anterior pituitary and parathyroid glands. We have targeted the murine Men1 gene by using Cre recombinase-loxP technology to develop both total and tissue-specific knockouts of the gene. Conditional homozygous inactivation of the Men1 gene in the pituitary gland and endocrine pancreas bypasses the embryonic lethality associated with a constitutional Men1(-/-) genotype and leads to beta-cell hyperplasia in less than 4 months and insulinomas and prolactinomas starting at 9 months. The pituitary gland and pancreas develop normally in the conditional absence of menin, but loss of this transcriptional cofactor is sufficient to cause beta-cell hyperplasia in some islets; however, such loss is not sufficient to initiate pituitary gland tumorigenesis, suggesting that additional genetic events are necessary for the latter

Genomic catastrophes frequently arise in esophageal adenocarcinoma and drive tumorigenesis

Oesophageal adenocarcinoma (EAC) incidence is rapidly increasing in Western countries. A better understanding of EAC underpins efforts to improve early detection and treatment outcomes. While large EAC exome sequencing efforts to date have found recurrent loss-offunction mutations, oncogenic driving events have been underrepresented. Here we use a combination of whole-genome sequencing (WGS) and single-nucleotide polymorphism-array profiling to show that genomic catastrophes are frequent in EAC, with almost a third (32%, n¼40/123) undergoing chromothriptic events. WGS of 22 EAC cases show that catastrophes may lead to oncogene amplification through chromothripsis-derived double-minute chromosome formation (MYC and MDM2) or breakage-fusion-bridge (KRAS, MDM2 and RFC3). Telomere shortening is more prominent in EACs bearing localized complex rearrangements. Mutational signature analysis also confirms that extreme genomic instability in EAC can be driven by somatic BRCA2 mutations. These findings suggest that genomic catastrophes have a significant role in the malignant transformation of EAC

Magnetic Behavior of a Mixed Ising Ferrimagnetic Model in an Oscillating Magnetic Field

The magnetic behavior of a mixed Ising ferrimagnetic system on a square lattice, in which the two interpenetrating square sublattices have spins +- 1/2 and spins +-1,0, in the presence of an oscillating magnetic field has been studied with Monte Carlo techniques. The model includes nearest and next-nearest neighbor interactions, a crystal field and the oscillating external field. By studying the hysteretic response of this model to an oscillating field we found that it qualitatively reproduces the increasing of the coercive field at the compensation temperature observed in real ferrimagnets, a crucial feature for magneto-optical applications. This behavior is basically independent of the frequency of the field and the size of the system. The magnetic response of the system is related to a dynamical transition from a paramagnetic to a ferromagnetic phase and to the different temperature dependence of the relaxation times of both sublattices.Comment: 10 figures. To be published in Phys.Rev

Formation of Giant Quasibound Cold Diatoms by Strong Atom-Cavity Coupling

We show that giant quasi-bound diatomic complexes, whose size is typically hundreds of nm, can be formed by intra-cavity cold diatom photoassociation or photodissociation in the strong atom-cavity coupling regime.Comment: 4 pages, 3 figure