The role of tropical forests in supporting biodiversity and hydrological integrity: a synoptic overview

Conservation of high-biodiversity tropical forests is sometimes justified on the basis of assumed hydrological benefits - in particular, the reduction of flooding hazards for downstream floodplain populations. However, the"far-field"link between deforestation and distant flooding has been difficult to demonstrate empirically. This simulation study assesses the relationship between forest cover and hydrology for all river basins intersecting the world's tropical forest biomes. The study develops a consistent set of pan-tropical land cover maps gridded at one-half degree latitude and longitude. It integrates these data with existing global biogeophysical data. The study applies the Water Balance Model - a coarse-scale process-based hydrological model - to assess the impact of land cover changes on runoff. It quantifies the impacts of forest conversion on biodiversity and hydrology for two scenarios - historical forest conversion and the potential future conversion of the most threatened remaining tropical forests. A worst-case scenario of complete conversion of the most threatened of the remaining forested areas would mean the loss of another three million km2 of tropical forests. Increased annual yield from the conversion of threatened tropical forests would be less than 5 percent of contemporary yield in aggregate. However, about 100 million people - 80 million of them in floodplains - would experience increases of more than 25 percent in annual water flows. This might be associated with commensurate increases in peak flows, though further analysis would be necessary to gauge the impact on flooding. The study highlights basins in Southeast Asia, southern China, and Latin America that warrant further study.Wetlands,Forestry,Climate Change,Drylands&Desertification,Earth Sciences&GIS

Slogans as Persuasive Accelerants of Electronic Word-of-Mouth Communication: A Preliminary Conceptual Model

Brands have been conceptualized as being made up of three different components: name, logo and slogan (Keller 1993, Dass, Kumar, Kohli, & Thomas, 2014). Slogans are short, memorable phrases that are often used to sign off on advertisements. They characterize a large proportion of brand advertising and are designed to attract consumer attention, crystallize brand positioning, increase advertising memorability, and improve brand affinity (Keller, 1993). Slogans have been part of our world for millennia, and a staple in the advertising world since its inception. Less complex messages – i.e., slogans – have been associated with improved advertising effectiveness (Lowrey 1998). Research into electronic word of mouth has grown rapidly. One reason is that online WOM elasticity has been found to be 2x larger than advertising’s (Hewett et. al, 2016). One recent advancement in creating and testing models of the eWOM process examined the relationship between several source and message characteristics on amplification and engagement Gourinovitch et. al (2019). The current paper will build upon this source-and-message model (see Figure 1). Slogans have rhetorical qualities that aid in gaining acceptance and dampening critique of the persuasive content (McQuarrie and Mick 1999). In some cases, their simple rhetorical nature may serve more as social expression of unified purpose than as communication to an intended audience. Slogans seem to be interpreted differently than textual information (Holbrook and Moore 1981; Holbrook 1982) and give the illusion of logical strength. We propose that because good slogans have persuasive strength and emotional elements, they can act as “accelerants” of eWOM. In social media, slogans most often appear in the form of hashtags, defined here as a word or phrase preceded by the symbol # that classifies or categorizes the accompanying text (such as a tweet). Not all hashtags include slogans, but slogans often do appear as hashtags in social media - for example: e.g., #Yeswecan, #Justdoit, #MAGA. Current models of word-of-mouth (WOM) persuasion and factors help explain the spread of electronic WOM (eWOM). However, little prior research has considered how rhetorical devices such as slogans may accelerate social media message acceptance and retransmission. The proposed model builds on prior theoretical work in source and message characteristics and their influence on eWOM in social media. The model predicts that message acceptance and retransmission is accelerated by high quality slogans – which often take the form of hashtags in social media – because they serve as a persuasive rhetorical device similar to enthymeme. We propose that how consumers perceive the quality of the slogan will determine if eWOM spreads slowly or quickly - a moderating effect. Our proposed model is shown in Figure 2. Future research will include a test of the full model using Twitter data. ABOUT THE AUTHORS Theo Lynn is Professor of Digital Business at Dublin City University Business School. Professor Lynn specializes in the role of digital technologies in transforming business processes. Pierangelo Rosati is an Assistant Professor in Business Analytics at Dublin City University Business School and a Co-Deputy Director of the Irish Institute of Digital Business (IIDB). Charles Wood is Professor of Marketing at the University of Tulsa

Search for Gamma-ray Emission from Dark Matter Annihilation in the Small Magellanic Cloud with the Fermi Large Area Telescope

The Small Magellanic Cloud (SMC) is the second-largest satellite galaxy of the Milky Way and is only 60 kpc away. As a nearby, massive, and dense object with relatively low astrophysical backgrounds, it is a natural target for dark matter indirect detection searches. In this work, we use six years of Pass 8 data from the Fermi Large Area Telescope to search for gamma-ray signals of dark matter annihilation in the SMC. Using data-driven fits to the gamma-ray backgrounds, and a combination of N-body simulations and direct measurements of rotation curves to estimate the SMC DM density profile, we found that the SMC was well described by standard astrophysical sources, and no signal from dark matter annihilation was detected. We set conservative upper limits on the dark matter annihilation cross section. These constraints are in agreement with stronger constraints set by searches in the Large Magellanic Cloud and approach the canonical thermal relic cross section at dark matter masses lower than 10 GeV in the $b\bar{b}$ and $\tau^+\tau^-$ channels.Comment: 17 pages, 11 figures. Accepted by PR

Transcriptomics modeling of the late-gestation fetal pituitary response to transient hypoxia

Background The late-gestation fetal sheep responds to hypoxia with physiological, neuroendocrine, and cellular responses that aid in fetal survival. The response of the fetus to hypoxia represents a coordinated effort to maximize oxygen transfer from the mother and minimize wasteful oxygen consumption by the fetus. While there have been many studies aimed at investigating the coordinated physiological and endocrine responses to hypoxia, and while immunohistochemical or in situ hybridization studies have revealed pathways supporting the endocrine function of the pituitary, there is little known about the coordinated cellular response of the pituitary to the hypoxia. Results Thirty min hypoxia (from 17.0±1.7 to 8.0±0.8 mm Hg, followed by 30 min normoxia) upregulated 595 and downregulated 790 genes in fetal pituitary (123-132 days' gestation; term = 147 days). Network inference of up- and down- regulated genes revealed a high degree of functional relatedness amongst the gene sets. Gene ontology analysis revealed upregulation of cellular metabolic processes (e.g., RNA synthesis, response to estrogens) and downregulation Conclusions The multiple analytical approaches used in this study suggests that the acute response to 30 min of transient hypoxia in the late-gestation fetus results in reduced cellular metabolism and a pattern of gene expression that is consistent with cellular oxygen and ATP starvation. In this early time point, we see a vigorous gene response. But, like the hypothalamus, the transcriptomic response is not consistent with mediation by HIF-1. If HIF-1 is a significant controller of gene expression in the fetal pituitary after hypoxia, it must be at a later time.Fil: Wood, Charles E.. University of Florida; Estados UnidosFil: Chang, Eileen I.. University of Florida; Estados UnidosFil: Richards, Elaine M.. University of Florida; Estados UnidosFil: Rabaglino, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Keller Wood, Maureen. University of Florida; Estados Unido

Permutation-adapted complete and independent basis for atomic cluster expansion descriptors

In many recent applications, particularly in the field of atom-centered descriptors for interatomic potentials, tensor products of spherical harmonics have been used to characterize complex atomic environments. When coupled with a radial basis, the atomic cluster expansion (ACE) basis is obtained. However, symmetrization with respect to both rotation and permutation results in an overcomplete set of ACE descriptors with linear dependencies occurring within blocks of functions corresponding to particular generalized Wigner symbols. All practical applications of ACE employ semi-numerical constructions to generate a complete, fully independent basis. While computationally tractable, the resultant basis cannot be expressed analytically, is susceptible to numerical instability, and thus has limited reproducibility. Here we present a procedure for generating explicit analytic expressions for a complete and independent set of ACE descriptors. The procedure uses a coupling scheme that is maximally symmetric w.r.t. permutation of the atoms, exposing the permutational symmetries of the generalized Wigner symbols, and yields a permutation-adapted rotationally and permutationally invariant basis (PA-RPI ACE). Theoretical support for the approach is presented, as well as numerical evidence of completeness and independence. A summary of explicit enumeration of PA-RPI functions up to rank 6 and polynomial degree 32 is provided. The PA-RPI blocks corresponding to particular generalized Wigner symbols may be either larger or smaller than the corresponding blocks in the simpler rotationally invariant basis. Finally, we demonstrate that basis functions of high polynomial degree persist under strong regularization, indicating the importance of not restricting the maximum degree of basis functions in ACE models a priori

A Legislative Proposal for Improving Materials Policymaking: Impacts and Issues

The materials data, forecasting, and analysis system is very important to the future materials policies of this country. Adequate, timely, and reliable data, forecasts, and analyses are not sufficient for effective policy to solve complicated national materials problems, but they are necessary for improving the public policymaking process. Under a contract from Congress’ Office of Technology Assessment, the present authors reviewed the existing repositories of materials information and the possibilities for improvement. We interviewed policymakers in government, private industry, and nonprofit organizations. In this Article we describe our principal recommendation resulting from that research, a proposal for a new Bureau of Materials Statistics and Forecasting, and analyze its probable effects on government, free enterprise, and the general public

Risk Factors for Early Childhood Infection of Human Herpesvirus-8 in Zambian Children: The Role of Early Childhood Feeding Practices

Background—Human herpesvirus-8 (HHV-8) infection in early childhood is common throughout sub-Saharan Africa with prevalence increasing throughout childhood. Specific routes of transmission have not been clearly delineated, though HHV-8 is present in high concentrations in saliva. Methods—To understand the horizontal transmission of HHV-8 within households to children we enrolled for cross-sectional analysis, 251 households including 254 children, age two and under, in Lusaka, Zambia. For all children, plasma was screened for HHV-8 and HIV-1 and health and behavioral questionnaires were completed. Multi-level logistic regression analysis was conducted to assess independent factors for HHV-8 infection in children. Results—Risk factors for HHV-8 infection included increasing number of HHV-8 positive household members [OR 2.5 (95% CI: 1.9, 3.3) P \u3c 0.01] and having a primary caregiver who tested the temperature of food with their tongue prior to feeding the child [OR 2.4 (95% CI: 1.93, 3.30) P =0.01]. Breastfeeding was protective against infection with HHV-8 for children [OR 0.3 (95% CI: 0.16, 0.72) P \u3c0.01]. Conclusions—These results indicate that exposure to HHV-8 in the household increases risk for early childhood infection with specific feeding behaviors likely playing a role in transmission. Impact—Interventions to protect children from infection should emphasize the possibility of infection through sharing of foods

Ponderomotive effects in multiphoton pair production

The Dirac-Heisenberg-Wigner formalism is employed to investigate electron-positron pair production in cylindrically symmetric but otherwise spatially inhomogeneous, oscillating electric fields. The oscillation frequencies are hereby tuned to obtain multiphoton pair production in the nonperturbative threshold regime. An effective mass as well as a trajectory-based semi-classical analysis are introduced in order to interpret the numerical results for the distribution functions as well as for the particle yields and spectra. The results, including the asymptotic particle spectra, display clear signatures of ponderomotive forces.Comment: 9 pages, 3 Tables, 3 Figure

Ketamine decreases inflammatory and immune pathways after transient hypoxia in late gestation fetal cerebral cortex

Transient hypoxia in pregnancy stimulates a physiological reflex response that redistributes blood flow and defends oxygen delivery to the fetal brain. We designed the present experiment to test the hypotheses that transient hypoxia produces damage of the cerebral cortex and that ketamine, an antagonist of NMDA receptors and a known anti-inflammatory agent, reduces the damage. Late gestation, chronically catheterized fetal sheep were subjected to a 30-min period of ventilatory hypoxia that decreased fetal PaO2 from 17 ± 1 to 10 ± 1 mmHg, or normoxia (PaO2 17 ± 1 mmHg), with or without pretreatment (10 min before hypoxia/normoxia) with ketamine (3 mg/kg, i.v.). One day (24 h) after hypoxia/normoxia, fetal cerebral cortex was removed and mRNA extracted for transcriptomics and systems biology analysis (n = 3-5 per group). Hypoxia stimulated a transcriptomic response consistent with a reduction in cellular metabolism and an increase in inflammation. Ketamine pretreatment reduced both of these responses. The inflammation response modeled with transcriptomic systems biology was validated by immunohistochemistry and showed increased abundance of microglia/macrophages after hypoxia in the cerebral cortical tissue that ketamine significantly reduced. We conclude that transient hypoxia produces inflammation of the fetal cerebral cortex and that ketamine, in a standard clinical dose, reduces the inflammation response.Fil: Chang, Eileen I.. University of Florida; Estados UnidosFil: Zárate, Miguel A.. University of Florida; Estados UnidosFil: Rabaglino, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Provincia de Córdoba. Ministerio de Ciencia y Técnica. Centro de Excelencia en Productos y Procesos de Córdoba; ArgentinaFil: Richards, Elaine M.. University of Florida; Estados UnidosFil: Arndt, Thomas J.. University of Florida; Estados UnidosFil: Keller Wood, Maureen. University of Florida; Estados UnidosFil: Wood, Charles E.. University of Florida; Estados Unido