Debate over the importance and meaning of native range in invasion biology: reply to Courchamp et al.

CommentDebate over the importance and meaning of nativerange in invasion biology: reply to Courchamp et al.Patricio Javier Pereyra1,2,3∗and Radu Cornel Guia¸su41Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos Almirante Storni (CIMAS), San Antonio Oeste,RioNegro,Argentina2Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina3Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, San Antonio Oeste, Rio Negro, Argentina4Biology Program, Glendon College, York University, 2275 Bayview Avenue, Toronto, Ontario, M4N 3M6, CanadaIn their response to Pereyra (2020), Courchamp et al.(2020) considered problems with the concept of nativerange in invasion biology. They start by agreeing withPereyra that the concept of native range has limitations,but then proceed to criticize the work for what theyperceive as “flawed logical reasoning,” “a misleading se-lection of examples,” “cherry picking,” and a failure toappreciate the usefulness of this admittedly poorly de-fined concept. Here, we respond to the criticisms ofCourchamp et al., while addressing the important prob-lems that remain with the application of the native rangeconcept.Fil: Pereyra, Patricio Javier. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; Argentina. Universidad Nacional del Comahue. Escuela de Ciencias Marinas; ArgentinaFil: Guiaşu, Radu Cornel. York University; Canad

Environmental differences between sites control the diet and nutrition of the carnivorous plant Drosera rotundifolia

Background and aims: Carnivorous plants are sensitive to small changes in resource availability, but few previous studies have examined how differences in nutrient and prey availability affect investment in and the benefit of carnivory. We studied the impact of site-level differences in resource availability on ecophysiological traits of carnivory for Drosera rotundifolia L. Methods: We measured prey availability, investment in carnivory (leaf stickiness), prey capture and diet of plants growing in two bogs with differences in N deposition and plant available N: Cors Fochno (0.62 g m−2 yr.−1, 353 μg l−1), Whixall Moss (1.37 g m−2 yr.−1, 1505 μg l−1). The total N amount per plant and the contributions of prey/root N to the plants’ N budget were calculated using a single isotope natural abundance method. Results: Plants at Whixall Moss invested less in carnivory, were less likely to capture prey, and were less reliant on prey-derived N (25.5% compared with 49.4%). Actual prey capture did not differ between sites. Diet composition differed – Cors Fochno plants captured 62% greater proportions of Diptera. Conclusions: Our results show site-level differences in plant diet and nutrition consistent with differences in resource availability. Similarity in actual prey capture may be explained by differences in leaf stickiness and prey abundance

Lepton Acceleration in Pulsar Wind Nebulae

Pulsar Wind Nebulae (PWNe) act as calorimeters for the relativistic pair winds emanating from within the pulsar light cylinder. Their radiative dissipation in various wavebands is significantly different from that of their pulsar central engines: the broadband spectra of PWNe possess characteristics distinct from those of pulsars, thereby demanding a site of lepton acceleration remote from the pulsar magnetosphere. A principal candidate for this locale is the pulsar wind termination shock, a putatively highly-oblique, ultra-relativistic MHD discontinuity. This paper summarizes key characteristics of relativistic shock acceleration germane to PWNe, using predominantly Monte Carlo simulation techniques that compare well with semi-analytic solutions of the diffusion-convection equation. The array of potential spectral indices for the pair distribution function is explored, defining how these depend critically on the parameters of the turbulent plasma in the shock environs. Injection efficiencies into the acceleration process are also addressed. Informative constraints on the frequency of particle scattering and the level of field turbulence are identified using the multiwavelength observations of selected PWNe. These suggest that the termination shock can be comfortably invoked as a principal injector of energetic leptons into PWNe without resorting to unrealistic properties for the shock layer turbulence or MHD structure.Comment: 19 pages, 5 figures, invited review to appear in Proc. of the inaugural ICREA Workshop on "The High-Energy Emission from Pulsars and their Systems" (2010), eds. N. Rea and D. Torres, (Springer Astrophysics and Space Science series

Isolation and characterization of resident endogenous c-Kit⁺ cardiac stem cells from the adult mouse and rat heart

This protocol describes the isolation of endogenous c-Kit (also known as CD117)-positive (c-Kit⁺), CD45-negative (CD45⁻) cardiac stem cells (eCSCs) from whole adult mouse and rat hearts. The heart is enzymatically digested via retrograde perfusion of the coronary circulation, resulting in rapid and extensive breakdown of the whole heart. Next, the tissue is mechanically dissociated further and cell fractions are separated by centrifugation. The c-Kit⁺ CD45⁻ eCSC population is isolated by magnetic-activated cell sorting technology and purity and cell numbers are assessed by flow cytometry. This process takes ∼4 h for mouse eCSCs or 4.5 h for rat eCSCs. We also describe how to characterize c-Kit⁺ CD45⁻ eCSCs. The c-Kit⁺ CD45⁻eCSCs exhibit the defining characteristics of stem cells: they are self-renewing, clonogenic and multipotent. This protocol also describes how to differentiate eCSCs into three main cardiac lineages: functional, beating cardiomyocytes, smooth muscle, and endothelial cells. These processes take 17-20 d

Healthcare workers and health care-associated infections: knowledge, attitudes, and behavior in emergency departments in Italy

<p>Abstract</p> <p>Background</p> <p>This survey assessed knowledge, attitudes, and compliance regarding standard precautions about health care-associated infections (HAIs) and the associated determinants among healthcare workers (HCWs) in emergency departments in Italy.</p> <p>Methods</p> <p>An anonymous questionnaire, self-administered by all HCWs in eight randomly selected non-academic acute general public hospitals, comprised questions on demographic and occupational characteristics; knowledge about the risks of acquiring and/or transmitting HAIs from/to a patient and standard precautions; attitudes toward guidelines and risk perceived of acquiring a HAI; practice of standard precautions; and sources of information.</p> <p>Results</p> <p>HCWs who know the risk of acquiring Hepatitis C (HCV) and Human Immunodeficiency Virus (HIV) from a patient were in practice from less years, worked fewer hours per week, knew that a HCW can transmit HCV and HIV to a patient, knew that HCV and HIV infections can be serious, and have received information from educational courses and scientific journals. Those who know that gloves, mask, protective eyewear, and hands hygiene after removing gloves are control measures were nurses, provided care to fewer patients, knew that HCWs' hands are vehicle for transmission of nosocomial pathogens, did not know that a HCW can transmit HCV and HIV to a patient, and have received information from educational courses and scientific journals. Being a nurse, knowing that HCWs' hands are vehicle for transmission of nosocomial pathogens, obtaining information from educational courses and scientific journals, and needing information were associated with a higher perceived risk of acquiring a HAI. HCWs who often or always used gloves and performed hands hygiene measures after removing gloves were nurses, provided care to fewer patients, and knew that hands hygiene after removing gloves was a control measure.</p> <p>Conclusions</p> <p>HCWs have high knowledge, positive attitudes, but low compliance concerning standard precautions. Nurses had higher knowledge, perceived risk, and appropriate HAIs' control measures than physicians and HCWs answered correctly and used appropriately control measures if have received information from educational courses and scientific journals.</p

A viscoelastic deadly fluid in carnivorous pitcher plants

Background : The carnivorous plants of the genus Nepenthes, widely distributed in the Asian tropics, rely mostly on nutrients derived from arthropods trapped in their pitcher-shaped leaves and digested by their enzymatic fluid. The genus exhibits a great diversity of prey and pitcher forms and its mechanism of trapping has long intrigued scientists. The slippery inner surfaces of the pitchers, which can be waxy or highly wettable, have so far been considered as the key trapping devices. However, the occurrence of species lacking such epidermal specializations but still effective at trapping insects suggests the possible implication of other mechanisms. Methodology/Principal Findings : Using a combination of insect bioassays, high-speed video and rheological measurements, we show that the digestive fluid of Nepenthes rafflesiana is highly viscoelastic and that this physical property is crucial for the retention of insects in its traps. Trapping efficiency is shown to remain strong even when the fluid is highly diluted by water, as long as the elastic relaxation time of the fluid is higher than the typical time scale of insect movements. Conclusions/Significance : This finding challenges the common classification of Nepenthes pitchers as simple passive traps and is of great adaptive significance for these tropical plants, which are often submitted to high rainfalls and variations in fluid concentration. The viscoelastic trap constitutes a cryptic but potentially widespread adaptation of Nepenthes species and could be a homologous trait shared through common ancestry with the sundew (Drosera) flypaper plants. Such large production of a highly viscoelastic biopolymer fluid in permanent pools is nevertheless unique in the plant kingdom and suggests novel applications for pest control