The QUAX proposal: a search of galactic axion with magnetic materials

Aim of the QUAX (QUaerere AXion) proposal is to exploit the interaction of cosmological axions with the spin of electrons in a magnetized sample. Their effect is equivalent to the application of an oscillating rf field with frequency and amplitude which are fixed by axion mass and coupling constant, respectively. The rf receiver module of the QUAX detector consists of magnetized samples with the Larmor resonance frequency tuned to the axion mass by a polarizing static magnetic field. The interaction of electrons with the axion-equivalent rf field produces oscillations in the total magnetization of the samples. To amplify such a tiny field, a pump field at the same frequency is applied in a direction orthogonal to the polarizing field. The induced oscillatory magnetization along the polarizing field is measured by a SQUID amplifier operated at its quantum noise level.Comment: 5 pages, Contribution for the proceedings of the TAUP2015, International Conference on Topics in Astroparticle and Underground Physics, 7-11 September 2015, Torino, Ital

Rat Race: Insider Advice on Landing Judicial Clerkships

For many, the judicial clerkship application process is, to quote Sir Winston Churchill, a “riddle wrapped in a mystery inside an enigma.” It is a frenzied “Pamplona-like” atmosphere that begins on Labor Day +1 and continues unabated for several weeks. The initial week is the make or break point in the application review process because it is then that the judge starts to read each application and makes a “yes” or “no” evaluation. If his vote is a “no,” then no further action is taken. If it is a “yes,” the application passes to the law clerks, who then begin their evaluation. Our experience reviewing these applications has led us to the unanimous conclusion that many applicants select their list of judges and put together their packets with little or no thought of strategy as to how to get their applications past this initial phase and into the “yes” pile. We would like to guide the judicial clerkship applicant through the application process by discussing how our chambers conducts the interview and selection process. Specifically, we hope to dispel rumors of what goes on behind the curtain, and ultimately shed some light on how a clerkship applicant could improve his or her chances of receiving an offer. Although this article reflects the viewpoint of only one chambers, our collective experience is broad. Judge Ruggero J. Aldisert has been receiving law clerk applications, interviewing candidates and selecting clerks since 1961. From the standpoint of sheer experience in the law clerk selection process, Judge Aldisert must be near the top of the list of current federal appellate judges. His two present law clerks, Ryan Kirkpatrick and James Stevens, each wear two battle stars for action in the application process. Kirkpatrick and Stevens earned their first star in 2004 when they survived the initial post-Labor Day “running of the bulls,” a term which appropriately describes the federal judiciary’s present hiring plan. The two clerks earned their second star a year later when they closely examined each of the 200 applicants in the 2005 “stampede” and ultimately helped to select the two best candidates to go on to future honors. The authors are fully aware that there is a vast amount of literature discussing the clerkship application process. Most of the literature is couched in somber academic tomes, one of which was serious enough to require 334 footnotes. Our treatment of the subject is far less scholarly. We will not be discussing the role of game theory or the use of the “medical-matching model” in law clerk selection. Our purpose is simply to provide an insider’s perspective into the clerkship application process and, in doing so, defend the following theses: Unless you are the Editor-in-Chief of your school’s main law review or one of the top five or ten students in your class, you need to set yourself apart from the competition. Your road to success is through the face-to-face interview with the Judge. In making this point, we depart from the truism in the decision-making process that writing a good brief is more important than oral argument. In your written applications you may have sterling academic records, stunning extracurricular activities, and superb references, but whether you get the job offer depends on how you perform at the personal interview

Essential nonlinearities in hearing

Our hearing organ, the cochlea, evidently poises itself at a Hopf bifurcation to maximize tuning and amplification. We show that in this condition several effects are expected to be generic: compression of the dynamic range, infinitely shrap tuning at zero input, and generation of combination tones. These effects are "essentially" nonlinear in that they become more marked the smaller the forcing: there is no audible sound soft enough not to evoke them. All the well-documented nonlinear aspects of hearing therefore appear to be consequences of the same underlying mechanism.Comment: 4 pages, 3 figure

Exploring complex networks via topological embedding on surfaces

We demonstrate that graphs embedded on surfaces are a powerful and practical tool to generate, characterize and simulate networks with a broad range of properties. Remarkably, the study of topologically embedded graphs is non-restrictive because any network can be embedded on a surface with sufficiently high genus. The local properties of the network are affected by the surface genus which, for example, produces significant changes in the degree distribution and in the clustering coefficient. The global properties of the graph are also strongly affected by the surface genus which is constraining the degree of interwoveness, changing the scaling properties from large-world-kind (small genus) to small- and ultra-small-world-kind (large genus). Two elementary moves allow the exploration of all networks embeddable on a given surface and naturally introduce a tool to develop a statistical mechanics description. Within such a framework, we study the properties of topologically-embedded graphs at high and low `temperatures' observing the formation of increasingly regular structures by cooling the system. We show that the cooling dynamics is strongly affected by the surface genus with the manifestation of a glassy-like freezing transitions occurring when the amount of topological disorder is low.Comment: 18 pages, 7 figure

Mathematics anxiety, working memory, and mathematics performance in secondary-school children

Mathematics anxiety (MA) has been defined as \u201ca feeling of tension and anxiety that interferes with the manipulation of numbers and the solving of math problems in a wide variety of ordinary life and academic situations\u201d. Previous studies have suggested that a notable proportion of children in primary and secondary school suffer from MA, which is negatively correlated with calculation skills. The processing efficiency and attentional control theories suggest that working memory (WM) also plays an important part in such anxious feelings. The present study aimed to analyze the academic achievement and cognitive profiles of students with high math anxiety (HMA) and low math anxiety (LMA). Specifically, 32 students with HMA and 34 with LMA matched for age, gender, generalized anxiety, and vocabulary attending sixth to eighth grades were selected from a larger sample. The two groups were tested on reading decoding, reading comprehension, mathematics achievement, and on verbal short-term memory and WM. Our findings showed that HMA students were weak in several measures of mathematics achievement, but not in reading and writing skills, and that students with HMA reported lower scores on short-term memory and WM performances (with associated difficulties in inhibiting irrelevant information) than children with LMA. In addition, a logistic regression showed that weaknesses in inhibitory control and fact retrieval were the strongest variables for classifying children as having HMA or LMA

Constructive algebraic renormalization of the abelian Higgs-Kibble model

We propose an algorithm, based on Algebraic Renormalization, that allows the restoration of Slavnov-Taylor invariance at every order of perturbation expansion for an anomaly-free BRS invariant gauge theory. The counterterms are explicitly constructed in terms of a set of one-particle-irreducible Feynman amplitudes evaluated at zero momentum (and derivatives of them). The approach is here discussed in the case of the abelian Higgs-Kibble model, where the zero momentum limit can be safely performed. The normalization conditions are imposed by means of the Slavnov-Taylor invariants and are chosen in order to simplify the calculation of the counterterms. In particular within this model all counterterms involving BRS external sources (anti-fields) can be put to zero with the exception of the fermion sector.Comment: Jul, 1998, 31 page

A Framework for Recommending Multimedia Cultural Visiting Paths

In this work, we present a general framework for Cultural Heritage applications able to uniformly manage heterogeneous multimedia data coming from several web repositories and to provide context- Aware recommendation services in order to generate dynamic multimedia visiting paths useful for the users during the exploration of different kinds of cultural sites. A specific application of our system within the cultural heritage domain is proposed together with some experimental results

Scanning Tunneling Spectroscopy study of paramagnetic superconducting β’’-ET4[(H3O)Fe(C2O4)3]•C6H5Br crystals

Scanning tunnelling spectroscopy (STS) and microscopy (STM) were performed on the paramagnetic molecular superconductor beta''-ET4[(H3O)Fe(C2O4)(3)]C6H5Br. Under ambient pressure, this compound is located near the boundary separating superconducting and insulating phases of the phase diagram. In spite of a strongly reduced critical temperature T-c (T-c = 4.0 K at the onset, zero resistance at T-c = 0.5 K), the low temperature STS spectra taken in the superconducting regions show strong similarities with the higher T-c ET kappa-derivatives series. We exploited different models for the density of states (DOS), with conventional and unconventional order parameters to take into account the role played by possible magnetic and non-magnetic disorder in the superconducting order parameter. The values of the superconducting order parameter obtained by the fitting procedure are close to the ones obtained on more metallic and higher T-c organic crystals and far above the BCS values, suggesting an intrinsic role of disorder in the superconductivity of organic superconductors and a further confirmation of the non-conventional superconductivity in such compounds