Twin-tube conduction radionuclide calorimeter

The complete calorimeter system used to measure powers from 0.1 W to 2 W of samples 1.5 in. in diameter by 5 in. in length is described. Calorimeter readout is by digital voltmeter. A sensitivity of 1501 mV/W at 1.327 W with on accuracy of 99.9% was obtained. Sample equilibrium time is 4 h. The twin-tube temperature measurement system compensates for thermostat temperature fiuctuations. Thermistors measure the temperature gradient produced by heat flow through a 5-in. length of 1.75-in.-o.d., 0.035-in.-wall brass tube. The thermistors are supplied with a constant operating current by current regulator diodes to simplify and improve operation. sn integral calibration heater surrounds the sample chamber. Reliability is enhanced by all-solid-state design. (auth

Quantum teleportation and entanglement swapping with linear optics logic gates

We report on the usage of a linear optics phase gate for distinguishing all four Bell states simultaneously in a quantum teleportation and entanglement swapping protocol. This is demonstrated by full state tomography of the one and two qubit output states of the two protocols, yielding average state fidelities of about 0.83 and 0.77, respectively. In addition, the performance of the teleportation channel is characterised by quantum process tomography. The non classical properties of the entanglement swapping output states are further confirmed by the violation of a CHSH-type Bell inequality of 2.14 on average.Comment: 11 pages, 3 figure

The weakly coupled fractional one-dimensional Schr\"{o}dinger operator with index 1<α≤2\bf 1<\alpha \leq 2

We study fundamental properties of the fractional, one-dimensional Weyl operator $\hat{\mathcal{P}}^{\alpha}$ densely defined on the Hilbert space $\mathcal{H}=L^2({\mathbb R},dx)$ and determine the asymptotic behaviour of both the free Green's function and its variation with respect to energy for bound states. In the sequel we specify the Birman-Schwinger representation for the Schr\"{o}dinger operator $K_{\alpha}\hat{\mathcal{P}}^{\alpha}-g|\hat{V}|$ and extract the finite-rank portion which is essential for the asymptotic expansion of the ground state. Finally, we determine necessary and sufficient conditions for there to be a bound state for small coupling constant $g$.Comment: 16 pages, 1 figur

The search for the primary tumor in metastasized gastroenteropancreatic neuroendocrine neoplasm.

Gastroenteropancreatic neuroendocrine tumors (NETs) often present as liver metastasis from a carcinoma of unknown primary. We recently showed that primary NETs from the pancreas, small intestine and stomach as well as their respective liver metastases differ from each other by the expression profile of the three genes CD302, PPWD1 and ABHB14B. The gene and protein expression of CD302, PPWD1, and ABHB14B was studied in abdominal NET metastases to identify the site of the respective primary tumors. Cryopreserved tissue from NET metastases collected in different institutions (group A: 29, group B: 50, group C: 132 specimens) were examined by comparative genomic hybridization (Agilent 105 K), gene expression analysis (Agilent 44 K) (groups A and B) and immunohistochemistry (group C). The data were blindly evaluated, i.e. without knowing the site of the primary. Gene expression analysis correctly revealed the primary in the ileum in 94 % of the cases of group A and in 58 % of group B. A pancreatic primary was predicted in 83 % (group A) and 20 % (group B), respectively. The combined sensitivity of group A and B was 75 % for ileal NETs and 38 % for pancreatic NETs. Immunohistochemical analysis of group C revealed an overall sensitivity of 80 %. Gene and protein expression analysis of CD302 and PPWD1 in NET metastases correctly identifies the primary in the pancreas or the ileum in 80 % of the cases, provided that the tissue is well preserved. Immunohistochemical profiling revealed CD302 as the best marker for ileal and PPWD1 for pancreatic detection

Cosmological Limits on the Neutrino Mass from the Lya Forest

The Lya forest in quasar spectra probes scales where massive neutrinos can strongly suppress the growth of mass fluctuations. Using hydrodynamic simulations with massive neutrinos, we successfully test techniques developed to measure the mass power spectrum from the forest. A recent observational measurement in conjunction with a conservative implementation of other cosmological constraints places upper limits on the neutrino mass: m_nu < 5.5 eV for all values of Omega_m, and m_nu < 2.4 (Omega_m/0.17 -1) eV, if 0.2 < Omega_m <0.5 as currently observationally favored (both 95 % C.L.).Comment: 4 pages, 2 ps figures, REVTex, submitted to Phys. Rev. Let

Two-Week versus Six-Month Sampling Interval in a Short-Term Natural History Study of Oral HPV Infection in an HIV-Positive Cohort

BACKGROUND: Oral HPV infections detected six-months apart were compared to those detected bi-weekly, in an HIV-positive cohort, during the intervening months to elucidate systematic biases introduced into natural history studies by sampling interval. METHODS: Fourteen consecutive oral rinse samples were collected every two weeks for six months from an HIV-positive cohort (n = 112) and evaluated for the presence of 37 HPV types. The cumulative probability of type-specific HPV detection at visits 1 through 14 was determined as a function of infection categorized at visits 1 and 14 as persistent, newly detected, cleared or absent. Transition models were used to evaluate the effect of HPV viral load (measured by RT-PCR for HPV 16, 18, 31, 33, 35) on infection persistence. RESULTS: The average point prevalence of oral HPV infection was similar at two-week and six-month sampling intervals (45% vs. 47%, p = 0.52), but cumulative prevalence was higher with the former (82% vs. 53%, p<0.001) as was the cumulative prevalence of type-specific infections (9.3% vs 3.8%, p<0.0001). Type-specific infections persistent under a six-month sampling interval had a high probability (0.93, 95%CI 0.83-0.98) of detection at 50% or more of the intervening visits and infections that were absent had a high probability (0.94, 95% CI 0.93-0.95) of no interval detection. The odds of detection at any visit significantly increased for each unit increase in HPV viral load at the previous visit. CONCLUSIONS: Six-month sampling is appropriate to model factors associated with type-specific oral HPV infection persistence but may misclassify HPV-exposed individuals as unexposed

The Space Density of Galaxy Peaks and the Linear Matter Power Spectrum

One way of recovering information about the initial conditions of the Universe is by measuring features of the cosmological density field which are preserved during gravitational evolution and galaxy formation. In this paper we study the total number density of peaks in a (galaxy) point distribution smoothed with a filter, evaluating its usefulness as a means of inferring the shape of the initial (matter) power spectrum. We find that in numerical simulations which start from Gaussian initial conditions, the peak density follows well that predicted by the theory of Gaussian density fields, even on scales where the clustering is mildly non-linear. For smaller filter scales, r \simlt 4-6 \hmpc, we see evidence of merging as the peak density decreases with time. On larger scales, the peak density is independent of time. One might also expect it to be fairly robust with respect to variations in biasing, i.e. the way galaxies trace mass fluctuations. We find that this is the case when we apply various biasing prescriptions to the matter distribution in simulations. If the initial conditions are Gaussian, it is possible to use the peak density measured from the evolved field to reconstruct the shape of the initial power spectrum. We describe a stable method for doing this and apply it to several biased and unbiased non-linear simulations. We are able to recover the slope of the linear matter power spectrum on scales k \simlt 0.4 \hmpc^{-1}. The reconstruction has the advantage of being independent of the cosmological parameters ($\Omega$, $\Lambda$, $H_0$) and of the clustering normalisation ($\sigma_8$). The peak density and reconstructed power spectrum slope therefore promise to be powerful discriminators between popular cosmological scenarios.Comment: ApJ submitted, 20 pages, Latex (aaspp4), 13 figures. Also available at http://www-astronomy.mps.ohio-state.edu/~racc

Revealing the community within: valuing the role of local community structures within evidence-based school intervention programmes

Schools and the families they serve are sometimes perceived as deficient and in need of fixing. One response has been the implementation of evidence-based family intervention programmes, which may be highly regulated and prescriptive as a condition of their (often philanthropic) funding. This article seeks to explore and bring to the foreground the often hidden role of the pre-existing, informal community networks with a view to more authentic evaluation of these externally imposed programmes. The article draws on a range of qualitative data reflecting the lived experiences of participants—including parents and other community members—in a family and parenting programme at an English primary school. The analysis uses the work of Tönnies as a theoretical lens. It suggests that while there are tensions caused by the rigid requirements of external programmes, these are overcome in many cases by the highly effective, but often unacknowledged, contributions of the informal aspects of community. It is argued that these operate within and complement the formal programme. Far from subverting the more overt procedures, they actually enable it to function successfully, leading to additional, unanticipated transformations among participants. The article concludes that these organic, often invisible connections need to be identified, documented and nurtured if their full potential is to be recognised and realised when evaluating similar interventions