Towards a more realistic sink particle algorithm for the RAMSES code

We present a new sink particle algorithm developed for the Adaptive Mesh Refinement code RAMSES. Our main addition is the use of a clump finder to identify density peaks and their associated regions (the peak patches). This allows us to unambiguously define a discrete set of dense molecular cores as potential sites for sink particle formation. Furthermore, we develop a new scheme to decide if the gas in which a sink could potentially form, is indeed gravitationally bound and rapidly collapsing. This is achieved using a general integral form of the virial theorem, where we use the curvature in the gravitational potential to correctly account for the background potential. We detail all the necessary steps to follow the evolution of sink particles in turbulent molecular cloud simulations, such as sink production, their trajectory integration, sink merging and finally the gas accretion rate onto an existing sink. We compare our new recipe for sink formation to other popular implementations. Statistical properties such as the sink mass function, the average sink mass and the sink multiplicity function are used to evaluate the impact that our new scheme has on accurately predicting fundamental quantities such as the stellar initial mass function or the stellar multiplicity function.Comment: submitted to MNRAS, 24 pages, 19 figures, 5 table

Constrained Quantization on Symplectic Manifolds and Quantum Distribution Functions

A quantization scheme based on the extension of phase space with application of constrained quantization technic is considered. The obtained method is similar to the geometric quantization. For constrained systems the problem of scalar product on the reduced Hilbert space is investigated and possible solution of this problem is done. Generalization of the Gupta-Bleuler like conditions is done by the minimization of quadratic fluctuations of quantum constraints. The scheme for the construction of generalized coherent states is considered and relation with Berezin quantization is found. The quantum distribution functions are introduced and their physical interpretation is discussed.Comment: 42 page

On the Dynamics of Supermassive Black Holes in Gas-Rich, Star-Forming Galaxies: the Case for Nuclear Star Cluster Coevolution

We introduce a new model for the formation and evolution of supermassive black holes (SMBHs) in the RAMSES code using sink particles, improving over previous work the treatment of gas accretion and dynamical evolution. This new model is tested against a suite of high-resolution simulations of an isolated, gas-rich, cooling halo. We study the effect of various feedback models on the SMBH growth and its dynamics within the galaxy. In runs without any feedback, the SMBH is trapped within a massive bulge and is therefore able to grow quickly, but only if the seed mass is chosen larger than the minimum Jeans mass resolved by the simulation. We demonstrate that, in the absence of supernovae (SN) feedback, the maximum SMBH mass is reached when Active Galactic Nucleus (AGN) heating balances gas cooling in the nuclear region. When our efficient SN feedback is included, it completely prevents bulge formation, so that massive gas clumps can perturb the SMBH orbit, and reduce the accretion rate significantly. To overcome this issue, we propose an observationally motivated model for the joint evolution of the SMBH and a parent nuclear star cluster (NSC), which allows the SMBH to remain in the nuclear region, grow fast and resist external perturbations. In this scenario, however, SN feedback controls the gas supply and the maximum SMBH mass now depends on the balance between AGN heating and gravity. We conclude that SMBH/NSC co-evolution is crucial for the growth of SMBH in high-z galaxies, the progenitors of massive elliptical today.Comment: accepted for publication in MNRA

Schizophrenia in older adults

Although the number of persons over the age of 55 with schizophrenia is expected to double over the next 20 years, the research data on older people with schizophrenia is limited. This appears to be because until the middle of the 20th century, it was assumed that mental illness in older people was a part of the aging process and older people are often excluded from research investigations. There is a need for nursing research to explore how people with schizophrenia, as they age, learn to manage their problems, as well as how those who are first diagnosed with schizophrenia in later life adapt to their illness. Mental health nurses need to be cautious in assigning premature labels to older adults with mental illness that may lead to unsubstantiated assumptions about levels of disability. Instead, they should realize individual potential regarding undiscovered strengths and should attempt to create interventions that recognize and foster personal development for older adults with schizophrenia

Dementia Praecox or the Group of Schizophrenias

"Our literature is replete with complaints about the chaotic state of the systematics of psychoses and every psychiatrist knows that it is impossible to come to any common understanding on the basis of the old diagnostic labels. ... Thus, not even the masters of science can make themselves understood on the basis of the old concepts and with many patients the number of diagnoses made equals the number of institutions they have been too. ... Errors are the greatest obstacles to the progress of science; to correct such errors is of more practical value than to achieve new knowledge. We have here eliminated chaos of terms behind which useful concepts of disease were mistakenly sought; we have eliminated a veritable forest of boundary posts, not one of which indicated any natural line of demarcation. ... By the term „dementia praecox“ or „schizophrenia“ we designate a group of psychoses whose course is at times chronic, at times marked by intermittent attacks, and which can stop or retrograde at any stage, but does not permit a full restitutio ad integrum. The disease is characterized by a specific type of alteration of thinking, feeling, and relation to the external world which appears nowhere else in this particular fashion." Eugen Bleuler. Dementia Praecox or the Group of Schizophrenias. Translated by Joseph Zinkin. International Universities Press, New York, 1950

Endocrinological Psychiatry and Psychology

This is the text of a lecture given before the Henry Ford Hospital medical staff by Dr. Bleuer, who is the son of Eugen Bleuler, his predecessor as chairman of psychiatry at the University of Zurich and the man who first named schizophrenia . It is printed here with Dr. Bleuler\u27s permission

Towards a more realistic sink particle algorithm for the ramses code

We present a new sink particle algorithm developed for the adaptive mesh refinement code ramses. Our main addition is the use of a clump finder to identify density peaks and their associated regions (the peak patches). This allows us to unambiguously define a discrete set of dense molecular cores as potential sites for sink particle formation. Furthermore, we develop a new scheme to decide if the gas in which a sink could potentially form, is indeed gravitationally bound and rapidly collapsing. This is achieved using a general integral form of the virial theorem, where we use the curvature in the gravitational potential to correctly account for the background potential. We detail all the necessary steps to follow the evolution of sink particles in turbulent molecular cloud simulations, such as sink production, their trajectory integration, sink merging and finally the gas accretion rate on to an existing sink. We compare our new recipe for sink formation to other popular implementations. Statistical properties such as the sink mass function, the average sink mass and the sink multiplicity function are used to evaluate the impact that our new scheme has on accurately predicting fundamental quantities such as the stellar initial mass function or the stellar multiplicity functio