Halo abundances within the cosmic web

We investigate the dependence of the mass function of dark-matter haloes on their environment within the cosmic web of large-scale structure. A dependence of the halo mass function on large-scale mean density is a standard element of cosmological theory, allowing mass-dependent biasing to be understood via the peak-background split. On the assumption of a Gaussian density field, this analysis can be extended to ask how the mass function depends on the geometrical environment: clusters, filaments, sheets and voids, as classified via the tidal tensor (the Hessian matrix of the gravitational potential). In linear theory, the problem can be solved exactly, and the result is attractively simple: the conditional mass function has no explicit dependence on the local tidal field, and is a function only of the local density on the filtering scale used to define the tidal tensor. There is nevertheless a strong implicit predicted dependence on geometrical environment, because the local density couples statistically to the derivatives of the potential. We compute the predictions of this model and study the limits of their validity by comparing them to results deduced empirically from $N$-body simulations. We have verified that, to a good approximation, the abundance of haloes in different environments depends only on their densities, and not on their tidal structure. In this sense we find relative differences between halo abundances in different environments with the same density which are smaller than 13%. Furthermore, for sufficiently large filtering scales, the agreement with the theoretical prediction is good, although there are important deviations from the Gaussian prediction at small, non-linear scales. We discuss how to obtain improved predictions in this regime, using the 'effective-universe' approach.Comment: 14 pages, 6 figures. Revision matching journal versio

Oil and Gas Reserves in the Siberian Shelf

The Arctic region must be the world’s largest storehouse of liquid and gaseous hydrocarbons, and the vast Siberian region, both “on land” and “off shore” must be considered with envy by the free-world’s geologists for its oil and gas potential. It is here estimated that the off shore continental shelf of U.S.S.R. Siberia contains a reserve of 200 billion barrels of oil and 500 trillion cut. ft. of gas. These very approximate figures come from meager data obtained from the literature on oil and gas discoveries in the Siberian Arctic, the basin location of these discoveries, and the projection of the petroliferous basins off shore to the continental shelf

Major Structures of the Rocky Mountains of Colorado and Utah

This paper describes the major structures of Colorado and Utah and presents a theory of origin based on new knowledge of the layering and constitution of the upper mantle and lower crust. It proposes that the Ancestral Rockies and the more modem ones of Cretaceous and early Tertiary age of both the shelf of Colorado and eastern Utah and the miogeosyncline of western Utah are the result of vertical uplifts of the silicic crust. The uplifts are caused by the rise, from the upper mantle, of basalt in scattered places to the base of the silicic crust. This rise domed the silicic crust and the overlying sedimentary veneer. The surficial structures are viewed as gravity-caused mass movements along the flanks of the uplifts and in addition, particularly in the miogeosyncline of western Utah, as synclinoria of Paleozoic strata between uplifts where folding and considerable bedding plane thrusting occurs. The theory also relates widespread magmatism to tectonism in a reasonable fashion. It recognizes that the Rocky Mountains have been a region of Cenozoic regional uplift in which possibly more energy was required than for the building of individual uplifts. This, too, is related to a transformation of the uppermost mantle into a lighter density state. And finally, the Basin and Range faulting of western Utah is viewed as the result of the rise of sufficient basalt from the mantle to form a continuous layer under the silicic crust of the miogeosyncline thus bringing into existence a new framework of forces. The surficial structures are framed about the primary uplifts, but the entire silicic crust becomes attenuated toward the Pacific as it is activated by a component of gravity on a mobilized lower crust

A Relativistic Description of Gentry's New Redshift Interpretation

We obtain a new expression of the Friedmann-Robertson-Walker metric, which is an analogue of a static chart of the de Sitter space-time. The reduced metric contains two functions, $M(T,R)$ and $\Psi(T,R)$, which are interpreted as, respectively, the mass function and the gravitational potential. We find that, near the coordinate origin, the reduced metric can be approximated in a static form and that the approximated metric function, $\Psi(R)$, satisfies the Poisson equation. Moreover, when the model parameters of the Friedmann-Robertson-Walker metric are suitably chosen, the approximated metric coincides with exact solutions of the Einstein equation with the perfect fluid matter. We then solve the radial geodesics on the approximated space-time to obtain the distance-redshift relation of geodesic sources observed by the comoving observer at the origin. We find that the redshift is expressed in terms of a peculiar velocity of the source and the metric function, $\Psi(R)$, evaluated at the source position, and one may think that this is a new interpretation of {\it Gentry's new redshift interpretation}.Comment: 11 pages. Submitted to Modern Physics Letters

Engaging men with penile cancer in qualitative research: reflections from an interview-based study.

To explore the challenges of engaging men with penile cancer in qualitative interview research

THE IMPACT OF PENILE CANCER TREATMENT ON SEXUAL RELATIONSHIPS: A QUALITATIVE ENQUIRY

Background: Penile cancer is a rare but highly treatable condition. Current guidance recommends the use of a surgical procedure to excise the primary tumour (and a margin of normal penile tissue). Whilst treatment can be effective, treatment often has a significant impact on a patient's sexual and urinary function, and physical and mental wellbeing. The objective of this study was to explore the impact of treatment for penile cancer on sexual function and relationships. Methods: Qualitative data was collected via narrative video interviews. Maximum variation sampling was used to acquire the widest possible range of experiences. All interviews were recorded using either a digital video recorder or digital audio recorder, transcribed. A method of constant comparison analysis was used to illicit themes and outliers. Results: Twenty seven men were interviewed; mean age at diagnosis = 63 (range = 41-82); Mean number of years post-surgery = 3 (range = 0-15 years) 15 men were married, a further two were in a committed relationship, the remaining 10 were single/widowed. All men had received surgical treatment ranging from circumcision to total penectomy. Just two men had attended any form of psychological therapy. The impact of treatment varied considerably. The majority of men talked about still being able to experience arousal and sexual pleasure in some way. However, for many, penetrative sex was awkward and less gratifying than before treatment. One man who had received a total penectomy was surprised to experience a form of orgasm after surgery. For a number of men, the impact of treatment on their ability to satisfy their sexual partners was a key concern. Men who were able to openly talk with their partners about sex and the impact of the treatment on sexual practice found this a great comfort. Conclusion: The significance of sex for a man can differ considerably between individuals; relationship status, age and life stage are all likely to have a bearing on the role that sex plays in a man life. A diagnosis of cancer can also affect how a man (and his partner) views sex and the level of importance which he attaches to it. For men who are sexually active prior to treatment, surgery will undoubtedly result in changes to sexual practice, however, treatment does not have to result in sexual abstinence

Pre-Congestion Notification (PCN) Architecture

This document describes a general architecture for flow admission and termination based on pre-congestion information in order to protect the quality of service of established, inelastic flows within a single Diffserv domain.\u

\u3ci\u3eKhyber calling\u3c/i\u3e

Khyber calling is the story of an Indian Frontier soldier. The object of the book is to try to sketch the life of a soldier. It consists of diary of principal events on the North-West Frontier of India

Resonant interaction of trapped cold atoms with a magnetic cantilever tip

Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a micro- cantilever with a magnetic tip. The cantilever is mounted on a multi-layer chip designed to capture, cool, and magnetically transport cold atoms. The coupling is observed by measuring the loss from a magnetic trap as the oscillating cantilever induces Zeeman state transitions in the atoms. Interfacing cold atoms with mechanical devices could enable probing and manipulating atomic spins with nanometer spatial resolution and single-spin sensitivity, leading to new capabilities in quantum computation, quantum simulation, or precision sensing.Comment: 5 pages, 4 figure

The role of the quantum properties of gravitational radiation in the dete ction of gravitational waves

The role that the quantum properties of a gravitational wave could play in the detection of gravitational radiation is analyzed. It is not only corroborated that in the current laser-interferometric detectors the resolution of the experimental apparatus could lie very far from the corresponding quantum threshold (thus the backreaction effect of the measuring device upon the gravitational wave is negligible), but it is also suggested that the consideration of the quantum properties of the wave could entail the definition of dispersion of the measurement outputs. This dispersion would be a function not only of the sensitivity of the measuring device, but also of the interaction time (between measuring device and gravitational radiation) and of the arm length of the corresponding laser- interferometer. It would have a minimum limit, and the introduction of the current experimental parameters insinuates that the dispersion of the existing proposals could lie very far from this minimum, which means that they would show a very large dispersion.Comment: 19 pages, Latex (use epsfig.sty