Shining new light on mammalian diving physiology using wearable near-infrared spectroscopy

Investigation of marine mammal dive-by-dive blood distribution and oxygenation has been limited by a lack of non-invasive technology for use in freely diving animals. Here, we developed a non-invasive near-infrared spectroscopy (NIRS) device to measure relative changes in blood volume and haemoglobin oxygenation continuously in the blubber and brain of voluntarily diving harbour seals. Our results show that seals routinely exhibit preparatory peripheral vasoconstriction accompanied by increased cerebral blood volume approximately 15 s before submersion. These anticipatory adjustments confirm that blood redistribution in seals is under some degree of cognitive control that precedes the mammalian dive response. Seals also routinely increase cerebral oxygenation at a consistent time during each dive, despite a lack of access to ambient air. We suggest that this frequent and reproducible reoxygenation pattern, without access to ambient air, is underpinned by previously unrecognised changes in cerebral drainage. The ability to track blood volume and oxygenation in different tissues using NIRS will facilitate a more accurate understanding of physiological plasticity in diving animals in an increasingly disturbed and exploited environment

Evaluation of spin in the abstracts of systematic reviews regarding the treatment of acne vulgaris

Background: Spin is the misrepresentation of study findings which may positively or negatively influence the reader's interpretation of the results. Little is known regarding the prevalence of spin in abstracts of systematic reviews — specifically systematic reviews pertaining to management and treatment for acne vulgaris.Objective: Our primary objective was to characterize and determine the frequency of the most severe forms of spin in systematic review abstracts, and to evaluate whether various study characteristics were associated with spin.Methods: Using a cross-sectional study design, we searched PubMed and Embase for systematic reviews focusing on the management and treatment of acne vulgaris. Our search returned 316 studies, of which 36 were included in our final sample. To be included, each systematic review must have addressed either pharmacologic or non-pharmacologic treatment of acne vulgaris. These studies were screened and data were extracted in duplicate by two blinded investigators. We analyzed systematic review abstracts for the 9 most severe types of spin.Results: Spin was present in 11 of 36 abstracts (30.56%). Twelve examples of spin were identified in the 11 abstracts containing spin, with one abstract containing two instances of spin. The most common type of spin, selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention, was identified 5 times (5/12, 41.67%). Sixteen of the 36 (16/36, 44.44%) studies did not report a risk of bias assessment. Of the 11 abstracts containing spin, 6 did not report a risk of bias assessment or performed a risk of bias assessment but did not discuss it (6/11, 54.55%). Spin in abstracts was not significantly associated with a specific intervention type, the use of a medical writer, funding source, journal impact factor, or PRISMA/PRISMA-A journal requirements.Conclusions: Abstracts with evidence of spin have the potential to influence clinical decision making. Therefore, further research is needed to evaluate what types of spin have the greatest influence on clinical practice. To help address the misrepresentation of study findings, we offer recommendations to better educate and improve peer-reviewers' and editors' awareness of, and ability to identify, spin in abstracts of systematic reviews

Structure-based discovery of glycomimetic FmlH ligands as inhibitors of bacterial adhesion during urinary tract infection

Significance The emergence of multidrug-resistant bacteria, including uropathogenic Escherichia coli (UPEC), makes the development of targeted antivirulence therapeutics a critical focus of research. During urinary tract infections (UTIs), UPEC uses chaperone–usher pathway pili tipped with an array of adhesins that recognize distinct receptors with sterochemical specificity to facilitate persistence in various tissues and habitats. We used an interdisciplinary approach driven by structural biology and synthetic glycoside chemistry to design and optimize glycomimetic inhibitors of the UPEC adhesin FmlH. These inhibitors competitively blocked FmlH in vitro, in in vivo mouse UTI models, and in ex vivo healthy human kidney tissue. This work demonstrates the utility of structure-driven drug design in the effort to develop antivirulence therapeutic compounds. </jats:p

Bringing Forecasting Into the Future: Using Google to Predict Visitation in U.S. National Parks

In recent years, visitation to U.S. National Parks has been increasing, with the majority of this increase occurring in a subset of parks. As a result, managers in these parks must respond quickly to increasing visitor-related challenges. Improved visitation forecasting would allow managers to more proactively plan for such increases. In this study, we leverage internet search data that is freely available through Google Trends to create a forecasting model. We compare this Google Trends model to a traditional autoregressive forecasting model. Overall, our Google Trends model accurately predicted 97% of the total visitation variation to all parks one year in advance from 2013 to 2017 and outperformed the autoregressive model by all metrics. While our Google Trends model performs better overall, this was not the case for each park unit individually; the accuracy of this model varied significantly from park to park. We hypothesized that park attributes related to trip planning would correlate with the accuracy of our Google Trends model, but none of the variables tested produced overly compelling results. Future research can continue exploring the utility of Google Trends to forecast visitor use in protected areas, or use methods demonstrated in this paper to explore alternative data sources to improve visitation forecasting in U.S. National Parks

Coherent mixing of mechanical excitations in nano-optomechanical structures

The combination of the large per-photon optical force and small motional mass achievable in nanocavity optomechanical systems results in strong dynamical back-action between mechanical motion and the cavity light field. In this Article, we study the optical control of mechanical motion within two different nanocavity structures, a zipper nanobeam photonic crystal cavity and a double-microdisk whispering-gallery resonator. The strong optical gradient force within these cavities is shown to introduce significant optical rigidity into the structure, with the dressed mechanical states renormalized into optically bright and optically dark modes of motion. With the addition of internal mechanical coupling between mechanical modes, a form of optically controlled mechanical transparency is demonstrated in analogy to electromagnetically induced transparency of three-level atomic media. Based upon these measurements, a proposal for coherently transferring radio-frequency/microwave signals between the optical field and a long-lived dark mechanical state is described

Radiative Cooling in Collisionally Ionized and Photoionized Plasmas

We discuss recent improvements in the calculation of the radiative cooling in both collisionally ionized and photoionized plasmas. We are extending the spectral simulation code CLOUDY so that as much as possible of the underlying atomic data are taken from external data bases, some created by others and some developed by the CLOUDY team. This paper focuses on recent changes in the treatment of many stages of ionization of iron, and discusses its extensions to other elements. The H- and He-like ions are treated in the isoelectronic approach described previously. Fe II is a special case treated with a large model atom. Here we focus on Fe III through Fe XXIV, ions which are important contributors to the radiative cooling of hot (T ∼ 105–107 K) plasmas and for X-ray spectroscopy. We use the Chianti atomic data base to greatly expand the number of transitions in the cooling function. Chianti only includes lines that have atomic data computed by sophisticated methods. This limits the line list to lower excitation, longer wavelength, transitions. We had previously included lines from the Opacity Project data base, which tends to include higher energy, shorter wavelength, transitions. These were combined with various forms of the ‘g-bar’ approximation, a highly approximate method of estimating collision rates. For several iron ions the two data bases are almost entirely complementary. We adopt a hybrid approach in which we use Chianti where possible, supplemented by lines from the Opacity Project for shorter wavelength transitions. The total cooling including the lightest 30 elements differs from some previous calculations by significant amounts

Salamander Abundance along Road Edges and within Abandoned Logging Roads in Appalachian Forests

Roads may be one of the most common disturbances in otherwise continuous forested habitat in the southern Appalachian Mountains. Despite their obvious presence on the landscape, there is limited data on the ecological effects along a road edge or the size of the “road-effect zone.” We sampled salamanders at current and abandoned road sites within the Nantahala National Forest, North Carolina (U.S.A.) to determine the road-effect zone for an assemblage of woodland salamanders. Salamander abundance near the road was reduced significantly, and salamanders along the edges were predominantly large individuals. These results indicate that the road-effect zone for these salamanders extended 35 m on either side of the relatively narrow, low-use forest roads along which we sampled. Furthermore, salamander abundance was significantly lower on old, abandoned logging roads compared with the adjacent upslope sites. These results indicate that forest roads and abandoned logging roads have negative effects on forest-dependent species such as plethodontid salamanders. Our results may apply to other protected forests in the southern Appalachians and may exemplify a problem created by current and past land use activities in all forested regions, especially those related to road building for natural-resource extraction. Our results show that the effect of roads reached well beyond their boundary and that abandonment or the decommissioning of roads did not reverse detrimental ecological effects; rather, our results indicate that management decisions have significant repercussions for generations to come. Furthermore, the quantity of suitable forested habitat in the protected areas we studied was significantly reduced: between 28.6% and 36.9% of the area was affected by roads. Management and policy decisions must use current and historical data on land use to understand cumulative impacts on forest-dependent species and to fully protect biodiversity on national landsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73456/1/j.1523-1739.2006.00571.x.pd

Two Novel Approaches for Electron Beam Polarization from Unstrained GaAs

Two novel approaches to producing highly-polarized electron beams from unstrained GaAs were tested using a micro-Mott polarimeter. Based on a suggestion by Nakanishi [1]], twophoton photoemission with 1560 nm light was used with photocathodes of varying thickness: 625m, 0.32m, and 0.18m. For each of these photocathodes, the degree of spin polarization of the photoemitted beam was less than 50%. Polarization via two-photon absorption was highest from the thinnest photocathode sample and close to that obtained from one-photon absorption (using 778 nm light), with values 40.3±1.0% and 42.6±1.0%, respectively. The second attempt to produce highly-polarized electrons used one-photon emission with 778 nm light in Laguerre-Gaussian modes with different amounts of orbital angular momentum. The degree of electron spin polarization was consistent with zero, with an upper limit of ~3% for light with up to ±5ħ of orbital angular momentum. In contrast, the degree of spin polarization was 32.3±1.4% using circularly-polarized laser light at the same wavelength, which is typical for thick, unstrained GaAs photocathodes

The use of non-uniform drowning terminology: a follow-up study

Background: In 2002, the World Congress on Drowning developed a uniform definition for drowning. The aim of this study is to determine the prevalence of “non-uniform drowning terminology� (NUDT) and “non-uniform drowning definitions� (NUDD) in peer-reviewed scientific literature from 2010 to 2016, and compare these findings with those from our unpublished study performing a similar analysis on literature from 2003 to 2010. Methods: A systematic review was performed using drowning-specific search terms in Pubmed and Web of Science. Titles and abstracts published between July 2010 and January 2016 were screened for relevance to the study focus. Articles meeting screening criteria were reviewed for exclusion criteria to produce the final group of studies. These articles were reviewed by four reviewers for NUDT and NUDD. The Fisher exact test was used to determine any statistically significant changes. Results: The final group of studies included 167 articles. A total of 53 articles (32%) utilized NUDT, with 100% of these including the term “near drowning�. The proportion of articles utilizing NUDT was significantly less than reported by our previous study (p < 0.05). In addition, 32% of the articles included a definition for drowning (uniform or non-uniform), with 15% of these utilizing NUDD. Discussion: Our study reveals a statistically significant improvement over the past thirteen years in the use of uniform drowning terminology in peer-reviewed scientific literature, although year-to-year variability over the current study period does not yield an obvious trend. Conclusions: Of the articles reviewed during the 2010-2016 study period, 32% included outdated and non-uniform drowning terminology and definitions. While this reveals an absolute decrease of 11% as compared with the previous study period (2003-2010), there is still significant room for improvement