M meson and a generalization of the Pomeranchuk relations

Under the hypothesis that a K-π resonance is vector, we examine its role in the associated production of Λ by π and in Λ production by K. We shall demonstrate the existence of a new symmetry between two reaction amplitudes. This symmetry may be regarded as a generalization of Pomeranchuk's relations and should appear at high energies and low momentum transfers when both amplitudes are dominated by the same pole or pseudopole, as is to be expected according to the Regge pole hypothesis. Specifically, we find, in considering the details of the role of a strange vector meson in the processes π+N→Λ+K and K +N→Λ+π, that the associated production amplitude in the forward direction (for the K) at high energies is asymptotically equal to the negative of the amplitude characterizing Λ production by a K. The contribution of the dominant pole terms in these amplitudes is constructed for the high-energy limit and the energy and momentum transfer dependences are compared for the alternative hypothesis of composite or elementary particle behavior of a pole term. We discuss experiments which are needed to supply data for a test of the Regge pole hypothesis. The results of these experiments, which are feasible with the new large accelerators, will be most important as guides for the construction of theories of the strong interactions

A Note on the Leptonic Decays of the K-Meson

In this note we present an analysis of the leptonic decay modes of the K-meson in terms of a four-parameter representation of the two form factors F1(q^2) and F3(q^2) which describe the matrix element of the vector current of the weak interactions, . Such a representation, while general enough to take account of the violation of the ΔΙ = 1/2 rule and the possible existence of two resonances in the K-π system, no longer permits unique predictions for the ratio of the electron to muon decay rate, or of the pion spectrum. We therefore suggest that experiments be carried out to determine the four unknown parameters, and theoretical attention be turned to relating these parameters to measurable quantities occurring in related processes

User Preference Analysis of Internet Social Media services

The size, scope and significance of Internet Social Media (ISM) services have grown exponentially in recent years. This paper discusses the context, methodology, findings, and conclusions from an exploratory study that assessed users’ preferences of ISM services. The study uses a mixed methods approach to explain why ISM services are liked or disliked by users. This is an important area for research since users are the most important stakeholders of any ISM service. The outcomes of this exploratory study were sets of rankings of ISM services that were based entirely on users\u27 preferences. This has not been studied in prior research up to this point. As Internet social networks continue to grow in their popularity and usefulness, this study provides a better understanding of the preferences of ISM users that is valuable to both academia and practitioners. The ISM services that are compared in this study include Facebook, MySpace, Google Plus, LinkedIn, Twitter, YouTube, Groupon, Digg, Yelp, and Loopt

A Note on the Leptonic Decays of the K-Meson

In this note we present an analysis of the leptonic decay modes of the K-meson in terms of a four-parameter representation of the two form factors F1(q^2) and F3(q^2) which describe the matrix element of the vector current of the weak interactions, . Such a representation, while general enough to take account of the violation of the ΔΙ = 1/2 rule and the possible existence of two resonances in the K-π system, no longer permits unique predictions for the ratio of the electron to muon decay rate, or of the pion spectrum. We therefore suggest that experiments be carried out to determine the four unknown parameters, and theoretical attention be turned to relating these parameters to measurable quantities occurring in related processes

Ursinus College Bulletin Vol. 11, No. 3, December 1894

A digitized copy of the December 1894 Ursinus College Bulletin.https://digitalcommons.ursinus.edu/ucbulletin/1100/thumbnail.jp

The theophylline‐enoxacin interaction: I. Effect of enoxacin dose size on theophylline disposition

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110004/1/cptclpt1988197.pd

Maximizing Data Quality using Mode Switching in Mixed-Device Survey Design: Nonresponse Bias and Models of Demographic Behavior

Conducting survey interviews on the internet has become an attractive method for lowering data collection costs and increasing the frequency of interviewing, especially in longitudinal studies. However, the advantages of the web mode for studies with frequent re-interviews can be offset by the serious disadvantage of low response rates and the potential for nonresponse bias to mislead investigators. Important life events, such as changes in employment status, relationship changes, or moving can cause attrition from longitudinal studies, producing the possibility of attrition bias. The potential extent of such bias in longitudinal web surveys is not well understood. We use data from the Relationship Dynamics and Social Life (RDSL) study to examine the potential for a mixed-device approach with active mode switching to reduce attrition bias. The RDSL design allows panel members to switch modes by integrating telephone interviewing into a longitudinal web survey with the objective of collecting weekly reports. We found that in this design allowing panel members to switch modes kept more participants in the study compared to a web only approach. The characteristics of persons who ever switched modes are different than those who did not – including not only demographic characteristics, but also baseline characteristics related to pregnancy and time-varying characteristics that were collected after the baseline interview. This was true in multivariate models that control for multiple of these dimensions simultaneously. We conclude that mode options and mode switching is important for the success of longitudinal web surveys to maximize participation and minimize attrition

Optimizing information flow in small genetic networks. II: Feed forward interactions

Central to the functioning of a living cell is its ability to control the readout or expression of information encoded in the genome. In many cases, a single transcription factor protein activates or represses the expression of many genes. As the concentration of the transcription factor varies, the target genes thus undergo correlated changes, and this redundancy limits the ability of the cell to transmit information about input signals. We explore how interactions among the target genes can reduce this redundancy and optimize information transmission. Our discussion builds on recent work [Tkacik et al, Phys Rev E 80, 031920 (2009)], and there are connections to much earlier work on the role of lateral inhibition in enhancing the efficiency of information transmission in neural circuits; for simplicity we consider here the case where the interactions have a feed forward structure, with no loops. Even with this limitation, the networks that optimize information transmission have a structure reminiscent of the networks found in real biological systems