1,195 research outputs found
Statistics of matrix elements of local operators in integrable models
We study the statistics of matrix elements of local operators in the basis of
energy eigenstates in a paradigmatic integrable many-particle quantum theory,
the Lieb-Liniger model of bosons with repulsive delta-function interaction.
Using methods of quantum integrability we determine the scaling of matrix
elements with system size. As a consequence of the extensive number of
conservation laws the structure of matrix elements is fundamentally different
from, and much more intricate than, the predictions of the eigenstate
thermalization hypothesis for generic models. We uncover an interesting
connection between this structure for local operators in interacting integrable
models, and the one for local operators that are not local with respect to the
elementary excitations in free theories. We find that typical off-diagonal
matrix elements in the
same macro-state scale as where the
probability distribution function for
are well described by Fr\'echet
distributions and depends only on macro-state information. In contrast,
typical off-diagonal matrix elements between two different macro-states scale
as , where depends only on macro-state information.
Diagonal matrix elements depend only on macro-state information up to
finite-size corrections.Comment: 30 pages, 40 figure
Physical accessible transformations on a finite number of quantum states
We consider to treat the usual probabilistic cloning, state separation,
unambiguous state discrimination, \emph{etc} in a uniform framework. All these
transformations can be regarded as special examples of generalized completely
positive trace non-increasing maps on a finite number of input states. From the
system-ancilla model we construct the corresponding unitary implementation of
pure pure, pure mixed, mixed pure, and mixed mixed
states transformations in the whole system and obtain the necessary and
sufficient conditions on the existence of the desired maps. We expect our work
will be helpful to explore what we can do on a finite set of input states.Comment: 7 page
Accelerators as authentic training experiences for nascent entrepreneurs
© 2017, © Emerald Publishing Limited. Purpose: The purpose of this paper is to address the role of accelerators as authentic learning-based entrepreneurial training programs. Accelerators facilitate the development and assessment of entrepreneurial competencies in nascent entrepreneurs through the process of creating a start-up venture. Design/methodology/approach: Survey data from applicants and participants of four start-accelerators are used to explore the linkages between accelerators and the elements of authentic learning. Authentic learning processes are then mapped onto the start-up processes that occur within the accelerators. Findings: Accelerators take in nascent entrepreneurs and work to create start-ups. This activity develops the participants’ entrepreneurial competencies and facilitates authentic self-reflection. Research limitations/implications: This study explores how accelerators can be useful as authentic learning platforms for the development of entrepreneurial competencies. Limitations include perceptual measures and the inability to conduct paired sampling. Practical implications: Entrepreneurship training is studied through the lens of authentic learning activities that occur within an accelerator. Participants develop and assess their mastery of and interest in entrepreneurship through tasks, exposure to experts and mentors, peer learning, and assessments such as pitching to investors at Demo Day. Originality/value: This paper reports on the authentic learning processes and its usefulness in competency development and self-appraisal by accelerators participants. The opportunity for competency development and self-appraisal by nascent entrepreneurs before escalating their commitment to a start-up may be an accelerator’s raison d’être
Combined use of zoledronic acid and 153Sm-EDTMP in hormone-refractory prostate cancer patients with bone metastases
Purpose: 153Sm-ethylenediaminetetramethylenephosphonic
acid (EDTMP; Quadramet®) is indicated for the treatment of
painful bone metastases, whereas zoledronic acid (Zometa®)
is indicated for the prevention of skeletal complications.
Because of the different therapeutic effects, combining the
treatments may be beneficial. Both, however, accumulate in
areas with increased osteoblastic activity. Possible drug
interactions were investigated.
Methods: Patients with hormone-refractory prostate cancer
were treated with 18.5 MBq/kg 153Sm-EDTMP in weeks 1
and 3 and with 37 MBq/kg in week 15. Treatment with 4 mg
zoledronic acid began in week 3 and continued every
4 weeks through week 23. In weeks 3 and 15, zoledronic
acid was administered 2 days before 153Sm-EDTMP
treatment. Urine was collected 48 h after injection of
153Sm-EDTMP, and whole-body images were obtained 6,
24 and 48 h post-injection. The effect of zoledronic acid on
total bone uptake of 153Sm-EDTMP was measured indirectly
by the cumulative activity excreted in the urine in weeks 1, 3
and 15. Biodistribution, safety, tolerability and effect on
prostate-specific antigen level were also studied.
Results: The urinary excretion in week 3 divided by the
urinary excretion in week 1 (baseline) times 100% was
mean 98.4±11.6% (median 96.2%). From week 1 to 15,
after four zoledronic acid treatments, the mean ratio was
101.9±10.7% (median 101.8%). Bioequivalence could be
concluded by using a two-sample t test for both perprotocol
(n=13) and full-analysis sets (n=18). Toxicity was
comparable to of monotherapy with 153Sm-EDTMP.
Conclusion: Zoledronic acid treatment does not influence
153Sm-EDTMP skeletal uptake. Combined treatment is
feasible and safe
Some geochemical constraints upon models for the crystallization of the upper critical zone-main zone interval, northwestern Bushveld complex
Ratios between elements Mg, Fe, Co, Cr, Ni, V, and Sc are consistently different in mafic rocks of the upper critical zone, and those above the Bastard unit. Within the 300 m section above the Merensky Reef, 87Sr/86Sr ratios increase from c.0.7063 to c.0.7087, irrespective of rock type. Decoupling of Mg/(Mg + Fe2+) ratios and the Ca contents of plagioclase, and wide variations in the proportions of anorthosite within the Bastard, Merensky, and Merensky Footwall units, are inconsistent with anorthosite formation by simple fractional crystallization of magma batches of limited volume
Face engagement during infancy predicts later face recognition ability in younger siblings of children with autism
Face recognition difficulties are frequently documented in children with autism spectrum disorders (ASD). It has been hypothesized that these difficulties result from a reduced interest in faces early in life, leading to decreased cortical specialization and atypical development of the neural circuitry for face processing. However, a recent study by our lab demonstrated that infants at increased familial risk for ASD, irrespective of their diagnostic status at 3 years, exhibit a clear orienting response to faces. The present study was conducted as a follow-up on the same cohort to investigate how measures of early engagement with faces relate to face-processing abilities later in life. We also investigated whether face recognition difficulties are specifically related to an ASD diagnosis, or whether they are present at a higher rate in all those at familial risk. At 3 years we found a reduced ability to recognize unfamiliar faces in the high-risk group that was not specific to those children who received an ASD diagnosis, consistent with face recognition difficulties being an endophenotype of the disorder. Furthermore, we found that longer looking at faces at 7 months was associated with poorer performance on the face recognition task at 3 years in the high- risk group. These findings suggest that longer looking at faces in infants at risk for ASD might reflect early face-processing difficulties and predicts difficulties with recognizing faces later in life
Face engagement during infancy predicts later face recognition ability in younger siblings of children with autism
Face recognition difficulties are frequently documented in children with autism spectrum disorders (ASD). It has been hypothesized that these difficulties result from a reduced interest in faces early in life, leading to decreased cortical specialization and atypical development of the neural circuitry for face processing. However, a recent study by our lab demonstrated that infants at increased familial risk for ASD, irrespective of their diagnostic status at 3 years, exhibit a clear orienting response to faces. The present study was conducted as a follow-up on the same cohort to investigate how measures of early engagement with faces relate to face-processing abilities later in life. We also investigated whether face recognition difficulties are specifically related to an ASD diagnosis, or whether they are present at a higher rate in all those at familial risk. At 3 years we found a reduced ability to recognize unfamiliar faces in the high-risk group that was not specific to those children who received an ASD diagnosis, consistent with face recognition difficulties being an endophenotype of the disorder. Furthermore, we found that longer looking at faces at 7 months was associated with poorer performance on the face recognition task at 3 years in the high- risk group. These findings suggest that longer looking at faces in infants at risk for ASD might reflect early face-processing difficulties and predicts difficulties with recognizing faces later in life
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