129 research outputs found
The cone of curves of Fano varieties of coindex four
We classify the cones of curves of Fano varieties of dimension greater or
equal than five and (pseudo)index dim X -3, describing the number and type of
their extremal rays.Comment: 27 pages; changed the numbering of Theorems, Definitions,
Propositions, etc. in accordance with the published version to avoid
incorrect reference
Addendum to: Capillary floating and the billiard ball problem
We compare the results of our earlier paper on the floating in neutral
equilibrium at arbitrary orientation in the sense of Finn-Young with the
literature on its counterpart in the sense of Archimedes. We add a few remarks
of personal and social-historical character.Comment: This is an addendum to my article Capillary floating and the billiard
ball problem, Journal of Mathematical Fluid Mechanics 14 (2012), 363 -- 38
Dipolar quantum solids emerging in a Hubbard quantum simulator
In quantum mechanical many-body systems, long-range and anisotropic
interactions promote rich spatial structure and can lead to quantum
frustration, giving rise to a wealth of complex, strongly correlated quantum
phases. Long-range interactions play an important role in nature; however,
quantum simulations of lattice systems have largely not been able to realize
such interactions. A wide range of efforts are underway to explore long-range
interacting lattice systems using polar molecules, Rydberg atoms, optical
cavities, and magnetic atoms. Here, we realize novel quantum phases in a
strongly correlated lattice system with long-range dipolar interactions using
ultracold magnetic erbium atoms. As we tune the dipolar interaction to be the
dominant energy scale in our system, we observe quantum phase transitions from
a superfluid into dipolar quantum solids, which we directly detect using
quantum gas microscopy with accordion lattices. Controlling the interaction
anisotropy by orienting the dipoles enables us to realize a variety of stripe
ordered states. Furthermore, by transitioning non-adiabatically through the
strongly correlated regime, we observe the emergence of a range of metastable
stripe-ordered states. This work demonstrates that novel strongly correlated
quantum phases can be realized using long-range dipolar interaction in optical
lattices, opening the door to quantum simulations of a wide range of lattice
models with long-range and anisotropic interactions
The use of a ward's history in training psychiatric child care workers
The importance of the contribution of historical-cultural factors to an inpatient treatment setting's contemporaneous psycho-social climate has been given little attention in published discussions of ward staff problems and training. This report illustrates some ways in which such historical-cultural forces, embodied in social myths and entrenched traditions, operate. Examples are provided from a ward of disturbed adolescents, where young child care workers struggled as a group with the daily stresses of providing therapeutic milieu support to children ambivalently seeking and resisting external controls for their feelings and impulses. The process of incorporating the analysis of historical-cultural factors in an inservice training program is described.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44275/1/10566_2005_Article_BF01642066.pd
Expanding the role of supervision in child psychiatric education
Despite the burgeoning of available therapeutic interventions, the sparse literature devoted to child psychiatric supervision concentrates on individual psychotherapy. The non-cognitive aspects of the expanding supervisory challenge continues to converge on the clinician's personality, which is a focus of educational attention only in sequestered or haphazard parts of programs. The unidimensional supervisory literature addresses this issue by questioning the extent to which supervision should resemble traditional pedagogy or personal psychotherapy. In contrast to this emphasis on elusive unconscious influences on clinical work, scant attention has been devoted to other influences stemming from the clinician's current experiences, affiliations, identifications, aspirations and similar more easily modifiable factors that exert considerable leverage and tend to be more accessible to rational scrutiny in supervision. The latter half of this paper discusses these factors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43974/1/10578_2005_Article_BF01463219.pd
QUARTIC DOUBLE SOLIDS WITH ICOSAHEDRAL SYMMETRY
We study quartic double solids admitting icosahedral symmetry.Comment: 19 page
HpaC Controls Substrate Specificity of the Xanthomonas Type III Secretion System
The Gram-negative bacterial plant pathogen Xanthomonas campestris pv. vesicatoria employs a type III secretion (T3S) system to inject bacterial effector proteins into the host cell cytoplasm. One essential pathogenicity factor is HrpB2, which is secreted by the T3S system. We show that secretion of HrpB2 is suppressed by HpaC, which was previously identified as a T3S control protein. Since HpaC promotes secretion of translocon and effector proteins but inhibits secretion of HrpB2, HpaC presumably acts as a T3S substrate specificity switch protein. Protein–protein interaction studies revealed that HpaC interacts with HrpB2 and the C-terminal domain of HrcU, a conserved inner membrane component of the T3S system. However, no interaction was observed between HpaC and the full-length HrcU protein. Analysis of HpaC deletion derivatives revealed that the binding site for the C-terminal domain of HrcU is essential for HpaC function. This suggests that HpaC binding to the HrcU C terminus is key for the control of T3S. The C terminus of HrcU also provides a binding site for HrpB2; however, no interaction was observed with other T3S substrates including pilus, translocon and effector proteins. This is in contrast to HrcU homologs from animal pathogenic bacteria suggesting evolution of distinct mechanisms in plant and animal pathogenic bacteria for T3S substrate recognition
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