3,073 research outputs found
Analysis of Spattering Activity at Halemaumau in 2015.
M.S. Thesis. University of HawaiÊ»i at MÄnoa 2017
On thermal nucleation of quark matter in compact stars
The possibility of a hadron-quark phase transition in extreme astrophysical
phenomena such as the collapse of a supernova is not discarded by the modern
knowledge of the high-energy nuclear and quark-matter equations of state. Both
the density and the temperature attainable in such extreme processes are
possibly high enough to trigger a chiral phase transition. However, the time
scales involved are an important issue. Even if the physical conditions for the
phase transition are favorable (for a system in equilibrium), there may not be
enough time for the dynamical process of phase conversion to be completed. We
analyze the relevant time scales for the phase conversion via thermal
nucleation of bubbles of quark matter and compare them to the typical
astrophysical time scale, in order to verify the feasibility of the scenario of
hadron-quark phase conversion during, for example, the core-collapse of a
supernova.Comment: 6 pages, 4 figures, talk given at the International Conference
SQM2009, Buzios, Rio de Janeiro, Brazil, Sep.27-Oct.2, 200
Evaluation of Aposphaeria amaranthi as a Bioherbicide for Pigweed (Amaranthus Spp.)
Studies were conducted to determine the potential of the fungus, Aposphaeria amaranth!, as a bioherbicide for pigweeds (Amaranthus spp.). Experiments to establish the environmental parameters necessary for control of tumble pigweed (A. albus) demonstrated that an 8-hr dew period was sufficient for control of seedlings with four to six leaves, and that temperatures ranging from 20 to 28 C were conducive for disease development. Conidial concentrations as lowas 1x 10s conidia per ml also were sufficient for plant mortality. Host range tests demonstrated pathogenicity of A. amaranthi to several other species of Amaranthus, including biotypes resistant to triazine herbicides. Disease on redroot pigweed (A. retroflexus) was enhanced by incorporation of surfactants into inoculum suspensions. Field tests conducted in 1990 resulted in 73% control of redroot pigweed and 99% control of tumble pigweed. These results suggest that Aposphaeria amaranthi has potential as a bioherbicide for controlling pigweeds
Gene Expression Profile Changes After Short-activating RNA-mediated Induction of Endogenous Pluripotency Factors in Human Mesenchymal Stem Cells
It is now recognized that small noncoding RNA sequences have the ability to mediate transcriptional activation of specific target genes in human cells. Using bioinformatics analysis and functional screening, we screened short-activating RNA (saRNA) oligonucleotides designed to target the promoter regions of the pluripotency reprogramming factors, Kruppel-like factor 4 (KLF4) and c-MYC. We identified KLF4 and c-MYC promoter-targeted saRNA sequences that consistently induced increases in their respective levels of nascent mRNA and protein expression in a time- and dose-dependent manner, as compared with scrambled sequence control oligonucleotides. The functional consequences of saRNA-induced activation of each targeted reprogramming factor were then characterized by comprehensively profiling changes in gene expression by microarray analysis, which revealed significant increases in mRNA levels of their respective downstream pathway genes. Notably, the microarray profile after saRNA-mediated induction of endogenous KLF4 and c-MYC showed similar gene expression patterns for stem cell- and cell cycle-related genes as compared with lentiviral vector-mediated overexpression of exogenous KLF4 and c-MYC transgenes, while divergent gene expression patterns common to viral vector-mediated transgene delivery were also noted. The use of promoter-targeted saRNAs for the activation of pluripotency reprogramming factors could have broad implications for stem cell research
Nucleation of quark matter in protoneutron star matter
The phase transition from hadronic to quark matter may take place already
during the early post-bounce stage of core collapse supernovae when matter is
still hot and lepton rich. If the phase transition is of first order and
exhibits a barrier, the formation of the new phase occurs via the nucleation of
droplets. We investigate the thermal nucleation of a quark phase in supernova
matter and calculate its rate for a wide range of physical parameters. We show
that the formation of the first droplet of a quark phase might be very fast and
therefore the phase transition to quark matter could play an important role in
the mechanism and dynamics of supernova explosions.Comment: v3: fits version published in Physical Review
Researching âbogusâ asylum seekers, âillegalâ migrants and âcrimmigrantsâ
Both immigration and criminal laws are, at their core, systems of inclusion and exclusion. They are designed to determine whether and how to include individuals as members of society or exclude them from it, thereby, creating insiders and outsiders (Stumpf 2006). Both are designed to create distinct categories of people â innocent versus guilty, admitted versus excluded or, as majority would say, âlegalâ versus âillegalâ (Stumpf 2006). Viewed in that light, perhaps it is not surprising that these two areas of law have become inextrica- bly connected in the official discourses. When politicians and policy makers (and also law enforcement authorities and tabloid press) seek to raise the barriers for non-citizens to attain membership in society, it is unremarkable that they turn their attention to an area of the law that similarly func- tions to exclude the âotherâ â transforming immigrants into âcrimmigrantsâ.1 As a criminological researcher one then has to rise up to the challenges of disentangling these so-called officially constructed (pseudo) realities, and breaking free from a continued dominance of authoritative discourses, and developing an alternative understanding of âcrimmigrationâ by connecting the processes of criminal is ation and âother ingâ with poverty, xe no-racism and other forms of social exclusion (see Institute of Race Relations 1987; Richmond 1994; Fekete 2001; Bowling and Phillips 2002; Sivanandan 2002; Weber and Bowling 2004)
Some remarks on the spectral functions of the Abelian Higgs Model
We consider the unitary Abelian Higgs model and investigate its spectral
functions at one-loop order. This analysis allows to disentangle what is
physical and what is not at the level of the elementary particle propagators,
in conjunction with the Nielsen identities. We highlight the role of the
tadpole graphs and the gauge choices to get sensible results. We also introduce
an Abelian Curci-Ferrari action coupled to a scalar field to model a massive
photon which, like the non-Abelian Curci-Ferarri model, is left invariant by a
modified non-nilpotent BRST symmetry. We clearly illustrate its non-unitary
nature directly from the spectral function viewpoint. This provides a
functional analogue of the Ojima observation in the canonical formalism: there
are ghost states with nonzero norm in the BRST-invariant states of the
Curci-Ferrari model.Comment: 32 pages, 12 figure
A Virtual Conversational Agent for Teens with Autism: Experimental Results and Design Lessons
We present the design of an online social skills development interface for
teenagers with autism spectrum disorder (ASD). The interface is intended to
enable private conversation practice anywhere, anytime using a web-browser.
Users converse informally with a virtual agent, receiving feedback on nonverbal
cues in real-time, and summary feedback. The prototype was developed in
consultation with an expert UX designer, two psychologists, and a pediatrician.
Using the data from 47 individuals, feedback and dialogue generation were
automated using a hidden Markov model and a schema-driven dialogue manager
capable of handling multi-topic conversations. We conducted a study with nine
high-functioning ASD teenagers. Through a thematic analysis of post-experiment
interviews, identified several key design considerations, notably: 1) Users
should be fully briefed at the outset about the purpose and limitations of the
system, to avoid unrealistic expectations. 2) An interface should incorporate
positive acknowledgment of behavior change. 3) Realistic appearance of a
virtual agent and responsiveness are important in engaging users. 4)
Conversation personalization, for instance in prompting laconic users for more
input and reciprocal questions, would help the teenagers engage for longer
terms and increase the system's utility
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