Some comments on "The Mathematical Universe"

I discuss some problems related to extreme mathematical realism, focusing on a recently proposed "shut-up-and-calculate" approach to physics (arXiv:0704.0646, arXiv:0709.4024). I offer arguments for a moderate alternative, the essence of which lies in the acceptance that mathematics is (at least in part) a human construction, and discuss concrete consequences of this--at first sight purely philosophical--difference in point of view.Comment: 11 page

Glacier loss and hydro-social risks in the Peruvian Andes

Accelerating glacier recession in tropical highlands and in the Peruvian Andes specifically is a manifestation of global climate change that is influencing the hydrologic cycle and impacting water resources across a range of socio-environmental systems. Despite predictions regarding the negative effects of long-term glacier decline on water availability, many uncertainties remain regarding the timing and variability of hydrologic changes and their impacts. To improve context-specific understandings of the effects of climate change and glacial melt on water resources in the tropical Andes, this article synthesizes results from long-term transdisciplinary research with new findings from two glacierized Peruvian watersheds to develop and apply a multi-level conceptual framework focused on the coupled biophysical and social determinants of water access and hydro-social risks in these contexts. The framework identifies several interacting variables—hydrologic transformation, land cover change, perceptions of water availability, water use and infrastructure in local and regional economies, and water rights and governance—to broadly assess how glacier change is embedded with social risks and vulnerability across diverse water uses and sectors. The primary focus is on the Santa River watershed draining the Cordillera Blanca to the Pacific. Additional analysis of hydrologic change and water access in the geographically distinct Shullcas River watershed draining the Huaytapallana massif towards the city of Huancayo further illuminates the heterogeneous character of hydrologic risk and vulnerability in the Andes

Stigma and Fear: the 'Psy Professional' in Cultural Artifacts

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The loss of reason called madness provokes perhaps the greatest human fear, for it is reason that dignifies humanity and separates us from beasts. The ‘psy professionals’ - those who prescribe and administer treatments for madness - are frequently portrayed in fiction, film, comics, computer games and entertainments, along with the mad themselves and the asylums that confine them. Overall, these depictions are malign: the reader/watcher/player is encouraged to fear the mad, the madhouse and the mad-doctor. Choosing to use less abrasive vocabulary to name the condition of madness makes no difference to the terror the condition arouses, for the content of many books and games aims to inspire fear. In spite of considerable efforts over many years, the stigma which attaches to mental illness remains firmly in place for patients, while psy professionals also carry their share of “some of the discredit of the stigmatized” (Goffman 1968, p 43) and join patients in a stigmatized group. Popular belief often equates the psy professions with madness (Walter, 1989). This paper explores ways in which the fear of madness, and the stigma which clings to sufferers and their professional carers, is perpetuated by a constant stream of popular cultural artifacts

Time-Dependent Models for a decade of SN 1993J

A classical and a relativistic law of motion for a supernova remnant (SNR) are deduced assuming an inverse power law behavior for the density of the interstellar medium and applying the thin layer approximation. A third equation of motion is found in the framework of relativistic hydrodynamics with pressure, applying momentum conservation. These new formulas are calibrated against a decade of observations of \snr. The existing knowledge of the diffusive processes of ultrarelativistic electrons is reviewed in order to explain the behavior of the `U' shaped profile of intensity versus distance from the center of SN 1993J.Comment: 20 pages 19 figures, Accepted for pubblication in Astrophysics and Space Science 201

The transfer of diatoms from freshwater to footwear materials: An experimental study assessing transfer, persistence, and extraction methods for forensic reconstruction

In recent years there has been growing interest in environmental forms of trace evidence, and ecological trace evidence collected from footwear has proved valuable within casework. Simultaneously, there has been growing awareness of the need for empirical experimentation to underpin forensic inferences. Diatoms are unicellular algae, and each cell (or ‘frustule’) consists of two valves which are made of silica, a robust material that favours their preservation both in sediments and within forensic scenarios. A series of experiments were carried out to investigate the transfer and persistence of diatoms upon common footwear materials, a recipient surface that has historically been overlooked by studies of persistence. The effectiveness of two novel extraction techniques (jet rinsing, and heating and agitation with distilled water) was compared to the established extraction technique of hydrogen peroxide digestion, for a suite of five common footwear materials: canvas, leather, and ‘suede’ (representing upper materials), and rubber and polyurethane (representing sole materials). It was observed that the novel extraction technique of heating and agitation with distilled water did not extract fewer diatom valves, or cause increased fragmentation of valves, when compared to peroxide digestion, suggesting that the method may be viable where potentially hazardous chemical reactions may be encountered with the peroxide digestion method. Valves could be extracted from all five footwear materials after 3 min of immersion, and more valves were extracted from the rougher, woven upper materials than the smoother sole materials. Canvas yielded the most valves (a mean of 2511/cm2) and polyurethane the fewest (a mean of 15/cm2). The persistence of diatoms on the three upper materials was addressed with a preliminary pilot investigation, with ten intervals sampled between 0 and 168 h. Valves were seen to persist in detectable quantities after 168 h on all three upper materials. However, some samples produced slides with no valves, and the earliest time after which no diatom valves were found was 4 h after the transfer. Analysis of the particle size distributions over time, by image analysis, suggests that the retention of diatoms may be size-selective; after 168 h, no particles larger than 200 μm2 could be found on the samples of canvas, and > 95% of the particles on the samples of suede were less than or equal to 200 μm2. A pilot investigation into the effects of immersion interval was carried out upon samples of canvas. Greater numbers of valves were extracted from the samples with longer immersion intervals, but even after 30 s, > 500 valves could be recovered per cm2, suggesting that footwear may be sampled for diatoms even if the contact with a water body may have been brief. These findings indicate that, if the variability within and between experimental runs can be addressed, there is significant potential for diatoms to be incorporated into the trace analysis of footwear and assist forensic reconstructions

Performance Issues in U.S.–China Joint Ventures

Based on an in-depth study of U.S.-China joint ventures, this article offers some insights into the performance of such international business relationships. While the conventional literature treats government as an amorphous aspea of the political-legal environment, in this case government is an active participant and influence in the performance of international joint ventures (UVs). It has both a constraining and enabling effect on LJV structure, strategy, and performance. For example, limits can be placed on ownership shares of joint ventures and on prices of the output. At the same time, government can cooperate with LJVs and foreign parent companies by creating partners for foreign parent companies, acting as major customers, and improving financial performance by lowering taxes

Risiken im Lebenszyklus: Theorie und Evidenz

Der einzelne Mensch ist im Lebensverlauf erheblichen biometrischen, ökonomischen, familiären und politischen Risiken ausgesetzt. Viele meinen, diese wären in den letzten Jahren größer geworden. Haben wir die richtigen Institutionen, um diese Risiken effizient abzudecken? Unter Institutionen verstehen wir individuelles Sparen, familiäre Hilfe, private Versicherungen und schließlich den Staat mit seinen Sozialversicherungen. Wo und wann funktionieren diese Institutionen? Wo und wann nicht? Was muss man tun, um sie zu verbessern? Wie sieht modernes "Social Risk Management" aus? Der erste Teil dieses Übersichtsbeitrags skizziert die wirtschaftstheoretischen Grundlagen des Sparverhaltens, der Portefeuillewahl und der Versicherungsnachfrage. Im Hauptteil werden die empirischen Befunde gesammelt, um im dritten Teil wirtschaftspolitische Schlussfolgerungen zu ziehen

Female genital tract shedding of HIV-1 is rare in women with suppressed HIV-1 in plasma

Objective: Determine the frequency of genital HIV-1 shedding in a large cohort of women on long-term suppressive antiretroviral therapy (ART) and its association with mucosal inflammation.Design:We measured levels of HIV-1 RNA and inflammation biomarkers in cervicovaginal lavage (CVL) from HIV-seropositive women enrolled in the Women's Interagency HIV Study (WIHS).Methods:HIV-1 was quantified (Abbott RealTime HIV-1 assay) from CVL samples of 332 WIHS participants with and without clinical evidence of genital inflammation at the time of CVL collection; participants had suppressed plasma viral load (PVL; limit of quantitation less than 20-4000copies/ml depending on year of collection) for a median of 7.1 years [interquartile range (IQR) 3.4-9.8, Group 1] or for a median of 1.0 years (IQR=0.5-1.0, Group 2). Twenty-two biomarkers of inflammation were measured in CVL to compare with clinical markers.Results:HIV-1 was detected in 47% of 38 pre-ART CVL samples (median 668copies/ml) and detection in CVL was associated with higher pre-ART PVL. HIV-1 was detected in only 1 of 38 CVL samples from these women on suppressive antiretroviral therapy for 1 year. No HIV-1 RNA was detected in 294 CVL samples from a cross-sectional set of women with suppressed PVL for a median of 7 years. Clinical inflammation markers were correlated with inflammatory biomarkers in CVL specimens, although genital inflammation was not associated with measurable genital HIV-1 shedding in these WIHS participants on ART.Conclusion:ART that suppresses HIV-1 in the plasma of women also prevents genital tract HIV-1 shedding, even in the presence of genital tract inflammation. Copyright © 2019 The Author(s)