780 research outputs found
Use of Multiple Stream Temperature Logger Models Can Alter Conclusions
Remote temperature loggers are often used to measure water temperatures for ecological studies and by regulatory agencies to determine whether water quality standards are being maintained. Equipment specifications are often given a cursory review in the methods; however, the effect of temperature logger model is rarely addressed in the discussion. In a laboratory environment, we compared measurements from three models of temperature loggers at 5 to 40 °C to better understand the utility of these devices. Mean water temperatures recorded by logger models differed statistically even for those with similar accuracy specifications, but were still within manufacturer accuracy specifications. Maximum mean temperature difference between models was 0.4 °C which could have regulatory and ecological implications, such as when a 0.3 °C temperature change triggers a water quality violation or increases species mortality rates. Additionally, precision should be reported as the overall precision (including a consideration of significant digits) for combined model types which in our experiment was 0.7 °C, not the â€0.4 °C for individual models. Our results affirm that analyzing data collected by different logger models can result in potentially erroneous conclusions when \u3c1 °C difference has regulatory compliance or ecological implications and that combining data from multiple logger models can reduce the overall precision of results
Bicrossed products for finite groups
We investigate one question regarding bicrossed products of finite groups
which we believe has the potential of being approachable for other classes of
algebraic objects (algebras, Hopf algebras). The problem is to classify the
groups that can be written as bicrossed products between groups of fixed
isomorphism types. The groups obtained as bicrossed products of two finite
cyclic groups, one being of prime order, are described.Comment: Final version: to appear in Algebras and Representation Theor
On the representation ring of the polynomial algebra over a perfect field
We consider the tensor product of modules over the polynomial algebra
corresponding to the usual tensor product of linear operators. We present a
general description of the representation ring in case the ground field k is
perfect. It is made explicit in the special cases when k is real closed
respectively algebraically closed. Furthermore, we discuss the generalisation
of this problem to representations of quivers. In particular the representation
ring of quivers of extended Dynkin type A is provided.Comment: 17 page
Constructing Fluorogenic Bacillus Spores (F-Spores) via Hydrophobic Decoration of Coat Proteins
Background: Bacterial spores are protected by a coat consisting of about 60 different proteins assembled as a biochemically complex structure with intriguing morphological and mechanical properties. Historically, the coat has been considered a static structure providing rigidity and mainly acting as a sieve to exclude exogenous large toxic molecules, such as lytic enzymes. Over recent years, however, new information about the coatâs architecture and function have emerged from experiments using innovative tools such as automated scanning microscopy, and high resolution atomic force microscopy. Principal Findings: Using thin-section electron microscopy, we found that the coat of Bacillus spores has topologically specific proteins forming a layer that is identifiable because it spontaneously becomes decorated with hydrophobic fluorogenic probes from the milieu. Moreover, spores with decorated coat proteins (termed F-spores) have the unexpected attribute of responding to external germination signals by generating intense fluorescence. Fluorescence data from diverse experimental designs, including F-spores constructed from five different Bacilli species, indicated that the fluorogenic ability of F-spores is under control of a putative germination-dependent mechanism. Conclusions: This work uncovers a novel attribute of spore-coat proteins that we exploited to decorate a specific layer imparting germination-dependent fluorogenicity to F-spores. We expect that F-spores will provide a model system to gai
State Sum Models and Simplicial Cohomology
We study a class of subdivision invariant lattice models based on the gauge
group , with particular emphasis on the four dimensional example. This
model is based upon the assignment of field variables to both the - and
-dimensional simplices of the simplicial complex. The property of
subdivision invariance is achieved when the coupling parameter is quantized and
the field configurations are restricted to satisfy a type of mod- flatness
condition. By explicit computation of the partition function for the manifold
, we establish that the theory has a quantum Hilbert space
which differs from the classical one.Comment: 28 pages, Latex, ITFA-94-13, (Expanded version with two new sections
Quantum Optics and Electronics
Contains reports on three research projects.U.S. Air Force - Office of Scientific Research (Contract F49620-79-C-0071)Joint Services Electronics Program (Contract DAAG29-78-C-0020)Joint Services Electronics Program (Contract DAAG29-80-C-0104)U.S. Navy - Office of Naval Research (Contract N00014-79-C-0694
Policy Comparison of Lead Hunting Ammunition Bans and Voluntary Nonlead Programs for California Condors
The endangered California condor (Gymnogyps californianus) is negatively affected by lead poisoning from spent leadâbased hunting ammunition. Because lead poisoning is the primary mortality factor affecting condors, the California Fish and Game Commission banned lead hunting ammunition during 2008 in the southern California condor range followed by a statewide ban implemented in 2019. In contrast, the Arizona Game and Fish Department instituted an outreach and awareness program encouraging voluntary use of nonlead hunting ammunition in the northern portion of the state during 2005 and a similar program was launched in Utah during 2012. The juxtaposition of policy tools provided a unique opportunity to evaluate the intended efforts to mitigate lead exposure in condors and their respective positive and negative effects. Herein we reflect upon the effectiveness of lead policy actions in the 3âstate region on the basis of condor bloodâlead levels, population status, and hunter awareness of the issue and use of nonlead hunting ammunition
Octonionic representations of Clifford algebras and triality
The theory of representations of Clifford algebras is extended to employ the
division algebra of the octonions or Cayley numbers. In particular, questions
that arise from the non-associativity and non-commutativity of this division
algebra are answered. Octonionic representations for Clifford algebras lead to
a notion of octonionic spinors and are used to give octonionic representations
of the respective orthogonal groups. Finally, the triality automorphisms are
shown to exhibit a manifest \perm_3 \times SO(8) structure in this framework.Comment: 33 page
Quantum Fourier transform, Heisenberg groups and quasiprobability distributions
This paper aims to explore the inherent connection among Heisenberg groups,
quantum Fourier transform and (quasiprobability) distribution functions.
Distribution functions for continuous and finite quantum systems are examined
first as a semiclassical approach to quantum probability distribution. This
leads to studying certain functionals of a pair of "conjugate" observables,
connected via the quantum Fourier transform. The Heisenberg groups emerge
naturally from this study and we take a rapid look at their representations.
The quantum Fourier transform appears as the intertwining operator of two
equivalent representation arising out of an automorphism of the group.
Distribution functions correspond to certain distinguished sets in the group
algebra. The marginal properties of a particular class of distribution
functions (Wigner distributions) arise from a class of automorphisms of the
group algebra of the Heisenberg group. We then study the reconstruction of
Wigner function from the marginal distributions via inverse Radon transform
giving explicit formulas. We consider applications of our approach to quantum
information processing and quantum process tomography.Comment: 39 page
When and how are lies told? And the role of culture and intentions in intelligenceâgathering interviews
Purpose: Lieâtellers tend to tell embedded lies within interviews. In the context of intelligenceâgathering interviews, human sources may disclose information about multiple events, some of which may be false. In two studies, we examined when lieâtellers from lowâ and highâcontext cultures start reporting false events in interviews and to what extent they provide a similar amount of detail for the false and truthful events. Study 1 focused on lieâtellers' intentions, and Study 2 focused on their actual responses. Methods: Participants were asked to think of one false event and three truthful events. Study 1 (N = 100) was an online study in which participants responded to a questionnaire about where they would position the false event when interviewed and they rated the amount of detail they would provide for the events. Study 2 (N = 126) was an experimental study that involved interviewing participants about the events. Results: Although there was no clear preference for lie position, participants seemed to report the false event at the end rather than at the beginning of the interview. Also, participants provided a similar amount of detail across events. Results on intentions (Study 1) partially overlapped with results on actual responses (Study 2). No differences emerged between lowâ and highâcontext cultures. Conclusions: This research is a first step towards understanding verbal cues that assist investigative practitioners in saving their cognitive and time resources when detecting deception regardless of interviewees' cultural background. More research on similar cues is encouraged
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