Neutron diffraction of hydrogenous materials: measuring incoherent and coherent intensities separately from liquid water - a 40-year-old puzzle solved

(short version) Accurate determination of the coherent static structure factor of disordered materials containing proton nuclei is prohibitively difficult by neutron diffraction, due to the large incoherent cross section of $^1$H. This notorious problem has set severe obstacles to the structure determination of hydrogenous materials up to now, via introducing large uncertainties into neutron diffraction data processing. Here we present the first accurate separate measurements, using polarized neutron diffraction, of the coherent and incoherent contributions to the total static structure factor of 5 mixtures of light and heavy water, over an unprecedentedly wide momentum transfer range. The structure factors of H$_2$O and D$_2$O mixtures derived in this work may signify the beginning of a new era in the structure determination of hydrogenous materials, using neutron diffraction.Comment: 8 page

High Time for Conservation: Adding the Environment to the Debate on Marijuana Liberalization

The liberalization of marijuana policies, including the legalization of medical and recreational marijuana, is sweeping the United States and other countries. Marijuana cultivation can have significant negative collateral effects on the environment that are often unknown or overlooked. Focusing on the state of California, where by some estimates 60% -- 70% of the marijuana consumed in the United States is grown, we argue that (a) the environmental harm caused by marijuana cultivation merits a direct policy response, (b) current approaches to governing the environmental effects are inadequate, and (c) neglecting discussion of the environmental impacts of cultivation when shaping future marijuana use and possession policies represents a missed opportunity to reduce, regulate, and mitigate environmental harm

Dependent wild bootstrap for the empirical process

In this paper, we propose a model-free bootstrap method for the empirical process under absolute regularity. More precisely, consistency of an adapted version of the so-called dependent wild bootstrap, that was introduced by Shao (2010) and is very easy to implement, is proved under minimal conditions on the tuning parameter of the procedure. We apply our results to construct confidence intervals for unknown parameters and to approximate critical values for statistical tests. A simulation study shows that our method is competitive to standard block bootstrap methods in finite samples

How do supply chain choices affect the life cycle impacts of medical products?

The natural resource based view (NRBV) of organisations suggests that there are two main models used by businesses to achieve short-term sustainability outcomes. They are the product stewardship and pollution prevention models. Here is the case of a New York-based wholesaler of medical supplies. The business aims to develop a more environmentally sustainable supply chain for one of its products - an emesis basin. The emesis basin is currently only offered in high-density polyethylene (HDPE) plastic, which has negative effects on the natural environment. This study aimed to assess how the focus of the business’ new business model might affect the overall life cycle impacts of this product. To achieve this, we compared the environmental impacts of the conventional product (Scenario 1– an HDPE basin) with equivalent products supplied via pollution prevention (Scenario 2 – a bioplastic basin) and product stewardship (Scenario 3 – green supply chain management and improvements) scenarios, as well as a combination scenario (Scenario 4). The results show that, in line with expectations, the pollution prevention option – switching to a bioplastic product – has the lowest environmental impacts. Unexpectedly though, the product stewardship option had a greater impact on the natural environment than the conventional HDPE, business-as-usual option. We suggest there may greater environmental gains to be obtained by focusing on one’s core business, than by extending influence to the entire supply chain

Recrutement des poissons dans le fjord du Saguenay

La faune ichtyologique du fjord du Saguenay est composée de plus de 60 espèces de poissons marins, diadromes et dulcicoles dont plusieurs font l’objet d’une pêche récréative comme l’éperlan arc-en-ciel anadrome (Osmerus mordax), le sébaste (Sebastes spp.), la morue franche (Gadus morhua), la morue ogac (Gadus ogac) et le flétan du Groenland (Reinhardtius hippoglossoides). On ignore si le recrutement des poissons marins exploités par la pêche récréative dans le Saguenay dépend de la production des stocks locaux ou des échanges avec les populations de l’estuaire du Saint-Laurent. Nous avons donc étudié la distribution spatio-temporelle de l’ichtyoplancton dans le fjord du Saguenay afin d’identifier les zones de production, de rétention et d’advection larvaires dans le but d’y préciser les mécanismes de recrutement des stocks de poissons. L’ichtyoplancton a été échantillonné à 21 stations sur le fjord du Saguenay à six occasions, de mai à octobre 2004, et à cinq occasions, de juin à septembre 2005. Les résultats montrent que le recrutement du capelan et de l’éperlan arc‑en‑ciel anadrome repose sur la production et la rétention des larves dans le fjord du Saguenay. Cependant, le recrutement des sébastes et des morues dépendrait de l’immigration de juvéniles en provenance de l’estuaire du Saint-Laurent. Ces résultats sont supportés par une revue des résultats des études antérieures sur les poissons du fjord du Saguenay. L’étude des mécanismes de recrutement des stocks de poissons du fjord du Saguenay favorise l’exploitation durable de ces ressources halieutiques conformément à la mission de Pêches et Océans Canada et dans le respect du programme de conservation du parc marin du Saguenay‑Saint-Laurent.In the Saguenay Fjord, the fish community is composed of more than 60 marine, diadromous and freshwater species, including many species exploited by the winter sport fishery such as the rainbow smelt (Osmerus mordax), redfish (Sebastes spp.), Atlantic cod (Gadus morhua), Greenland cod (Gadus ogac), and Greenland halibut (Reinhardtius hippoglossoides). We do not know if the recruitment of the fish species exploited by the winter sport fishery depends on the local production of recruits in the Saguenay Fjord or on exchanges with the St. Lawrence Estuary populations. Hence, we measured the spatio-temporal distribution of ichthyoplankton in the Fjord to identify zones of larval production, retention or advection, in order to investigate the recruitment mechanisms of these stocks. We sampled ichthyoplankton at 21 stations on six occasions, from May to October 2004, and on five occasions, from June to September 2005. Results indicated that the recruitment of capelin (Mallotus villosus) and of the anadromous rainbow smelt (Osmerus mordax) relied on the local production and retention of larvae within the Fjord. However, the recruitment of redfish (Sebastes spp.) and cods (Gadus spp.) depended on the immigration of juveniles from the St. Lawrence Estuary. Our results are corroborated by a review of previous studies of these fish populations. Studying the recruitment mechanisms of fish populations in the Saguenay Fjord supports a sustainable exploitation of these locally important fisheries resources, in accordance with the mission of Fisheries and Oceans Canada and consistent with the conservation program of the Saguenay St. Lawrence Marine Park

Microalbuminuria, but not cystatin C, is associated with carotid atherosclerosis in middle-aged adults

Background. Cystatin C, a marker of renal function, has been shown to be an independent predictor of cardiovascular disease (CVD) in older adults, but few data are available in middle-aged adults. Moreover, no study has compared cystatin C and microalbuminuria as risk factors for CVD outcomes in middle-aged adults, and it is not known whether cystatin C is related to an early stage of atherosclerosis. Methods. We evaluated the relationships between serum creatinine, estimated glomerular filtration rate (GFR), serum cystatin C (all divided into tertiles), microalbuminuria and carotid atherosclerosis in a population-based random sample of 523 adults aged 35-64 years from the Seychelles (Indian Ocean). GFR was estimated using the modification of diet in renal disease (MDRD) equation. Intima-media thickness (IMT) was assessed by B-mode ultrasound. Results. The mean age of the study sample was 52 years, and 55% were women. Carotid IMT was higher in participants with microalbuminuria (802 vs 732 μm, P < 0.001) and was inversely associated with GFR tertiles (from 728 to 809 μm, P for trend = 0.002). IMT was not associated with cystatin C or creatinine (P for trend = 0.10 and 0.16, respectively). In multivariate analyses adjusted for cardiovascular risk factors, the association between microalbuminuria and IMT remained (P = 0.047), while the association between GFR and IMT disappeared (P for trend = 0.33). Conclusions. Microalbuminuria, but not cystatin C, is associated with carotid atherosclerosis beyond traditional cardiovascular risk factors among middle-aged adults. Cystatin C does not have a stronger relationship with carotid atherosclerosis in middle-aged adults than creatinin