885 research outputs found
Half-integral finite surgeries on knots in
Suppose that a hyperbolic knot in admits a finite surgery, Boyer and
Zhang proved that the surgery slope must be either integral or half-integral,
and they conjectured that the latter case does not happen. Using the correction
terms in Heegaard Floer homology, we prove that if a hyperbolic knot in
admits a half-integral finite surgery, then the knot must have the same knot
Floer homology as one of eight non-hyperbolic knots which are known to admit
such surgeries, and the resulting manifold must be one of ten spherical space
forms. As knot Floer homology carries a lot of information about the knot, this
gives a strong evidence to Boyer--Zhang's conjecture.Comment: 15 page
Butterfly Factorization
The paper introduces the butterfly factorization as a data-sparse
approximation for the matrices that satisfy a complementary low-rank property.
The factorization can be constructed efficiently if either fast algorithms for
applying the matrix and its adjoint are available or the entries of the matrix
can be sampled individually. For an matrix, the resulting
factorization is a product of sparse matrices, each with
non-zero entries. Hence, it can be applied rapidly in operations.
Numerical results are provided to demonstrate the effectiveness of the
butterfly factorization and its construction algorithms
Asynchronous Decision-Making in Distributed Teams
Extensive use of CSCW applications can influence group decision-making practices. Unlike previous research focused on the influence of synchronous ICTs, our study examines how group decisions are made in asynchronous communication channels. Our inductive qualitative analysis of 360 decision episodes of six FLOSS projects revealed diversity in decision-making practices, which appears to be related to differences in project effectiveness and task type. We also find that standardization of procedures through CSCW tools transforms the nature of some software development work from non-routine to standard procedure
Ammonia Emissions from Layer Houses
Ammonia (NH3 ) emission rates from six high-rise (HR) and four manure-belt (MB) laying hen houses were measured for one year. Manure was stored in the lower level of the HR houses for a year, but removed daily or semiweekly from the MB houses. The results revealed an annual average NH3 emission rate of 0.87 (Ā±0.29) g d-1 hen-1 for the HR houses, 0.094 (Ā±0.062) for the MB houses with semiweekly manure removal, and 0.054 (Ā±0.026) g d-1 hen-1 for the MB houses with daily manure removal. Information of this study contributes to the U.S. national inventory on ammonia emissions from animal feeding operations with different housing and manure handling schemes and geographical locations
Heat shock-induced phosphorylation of TAR DNA-binding protein 43 (TDP-43) by MAPK/ERK kinase regulates TDP-43 function
TAR DNA-binding protein (TDP-43) is a highly conserved and essential DNA- and RNA-binding protein that controls gene expression through RNA processing, in particular, regulation of splicing. Intracellular aggregation of TDP-43 is a hallmark of amyotrophic lateral sclerosis and ubiquitin-positive frontotemporal lobar degeneration. This TDP-43 pathology is also present in other types of neurodegeneration including Alzheimer's disease. We report here that TDP-43 is a substrate of MEK, a central kinase in the MAPK/ERK signaling pathway. TDP-43 dual phosphorylation by MEK, at threonine 153 and tyrosine 155 (p-T153/Y155), was dramatically increased by the heat shock response (HSR) in human cells. HSR promotes cell survival under proteotoxic conditions by maintaining protein homeostasis and preventing protein misfolding. MEK is activated by HSR and contributes to the regulation of proteome stability. Phosphorylated TDP-43 was not associated with TDP-43 aggregation, and p-T153/Y155 remained soluble under conditions that promote protein misfolding. We found that active MEK significantly alters TDP-43-regulated splicing and that phosphomimetic substitutions at these two residues reduce binding to GU-rich RNA. Cellular imaging using a phospho-specific p-T153/Y155 antibody showed that phosphorylated TDP-43 was specifically recruited to the nucleoli, suggesting that p-T153/Y155 regulates a previously unappreciated function of TDP-43 in the processing of nucleolar-associated RNA. These findings highlight a new mechanism that regulates TDP-43 function and homeostasis through phosphorylation and, therefore, may contribute to the development of strategies to prevent TDP-43 aggregation and to uncover previously unexplored roles of TDP-43 in cell metabolism
Decision Making Paths in Self-Organizing Technology-Mediated Distributed Teams
This paper investigates decision making in self-organizing technology-mediated distributed teams. This context provides an opportunity to examine how the use of technological support to span temporal and organizational discontinuities affects decision-making processes. 258 software-modification decision episodes were collected from the public emailing lists of six Free/Libre Open Source Software (FLOSS) projects over a span of five years. Six decision-making paths were identified as 1) short-cut decision-making path; 2) implicit-development decision-making path; 3) implicit-evaluation decision-making path; 4) normative decision-making path; 5) dynamic decision-making path; and 6) interrupted/delayed decision-making path. We suggest that the nature of the tasks and the affordances of the technology used reduce the need for explicit coordination, resulting in a broader range of possible decision processes than are observed in face-to-face groups
Emergent Decision-Making Practices In Technology-Supported Self-Organizing Distributed Teams
We seek to identify work practices that make technology-supported, self-organizing, distributed (or virtual) teams (TSSODT for short) effective in producing outputs satisfactory to their sponsors, meeting the needs of their members, and continuing to function. A particularly important practice for team effectiveness is decision making: are the right decisions made at the right time to get the work done in a way that satisfies team sponsors, keeps contributors happy and engaged, and enables continued team success? In this research-in-progress paper, we report on an inductive qualitative analysis of 120 decision episodes taken by two Free/Libre Open Source Software development teams. Our analysis revealed differences in decision-making practices that seem to be related to differences in overall team effectiveness
Determination of pharmacy studentsā patient safety approach using the theory of planned behaviour: a mixed-method study
OBJECTIVES: To investigate pharmacy studentsā attitudes, subjective norms, perceived behavioural control, intentions and their behaviour towards patient safety using a theory of planned behaviour framework. DESIGN: Mixed-methods research. SETTING: Private university in Malaysia. PARTICIPANTS: Pharmacy undergraduate students participated in the study. There were 18 students participated in the qualitative study and 272 students responded to the survey questionnaire. METHODS: A convergent parallel-mixed method design, involving a quantitative survey and qualitative focus group discussions was used among pharmacy students in a private university in Malaysia. Qualitative data of transcribed verbatim texts were then subjected to a thematic content analysis framework. Multiple correlations were undertaken using the quantitative data to examine how the dependent variable (self-reported knowledge) related to the independent variables (attitudes, behavioural intentions, subjective norms, perceived behavioural control. PRIMARY OUTCOME: Pharmacy studentsā attitudes, subjective norms, perceived behavioural control, behavioural intentions constructs led to their behaviour towards patient safety. SECONDARY OUTCOME: The quantitative study revealed that there was a moderate positive correlation between studentsā self-reported knowledge and attitudes (r=0.48, p=0.03). RESULTS: Pharmacy studentsā attitudes and perceived behavioural control constructs had positive correlations with pharmacy studentsā self-reported knowledge on patient safety. There was no correlation between studentsā self-reported knowledge and subjective norms (r=0.27, p=0.23). There was a weak positive correlation between studentsā self-reported knowledge and perceived behavioural control (r=0.39, p=0.04). There was no correlation between studentsā self-reported knowledge and behavioural intention (r=0.20, p=0.56). CONCLUSIONS: Theory of planned behaviour constructs such as attitudes, subjective norms, perceived behavioural control and behavioural intentions of pharmacy students, defined their behaviour towards patient safety. Pharmacy studentsā attitudes and perceived behavioural control constructs were correlated with their self-reported knowledge on patient safety
- ā¦