Universidad del Este

About: Universidad del Este is a education organization based out in Carolina, Puerto Rico, United States. It is known for research contribution in the topics: Population & Social media. The organization has 79 authors who have published 85 publications receiving 947 citations. The organization is also known as: UNE.

Are We Underestimating Microplastic Contamination in Aquatic Environments

Abstract: Plastic debris, specifically microplastic in the aquatic environment, is an escalating environmental crisis. Efforts at national scales to reduce or ban microplastics in personal care products are starting to pay off, but this will not affect those materials already in the environment or those that result from unregulated products and materials. To better inform future microplastic research and mitigation efforts this study (1) evaluates methods currently used to quantify microplastics in the environment and (2) characterizes the concentration and size distribution of microplastics in a variety of products. In this study, 50 published aquatic surveys were reviewed and they demonstrated that most (~80%) only account for plastics ≥ 300 μm in diameter. In addition, we surveyed 770 personal care products to determine the occurrence, concentration and size distribution of polyethylene microbeads. Particle concentrations ranged from 1.9 to 71.9 mg g-1 of product or 1649 to 31,266 particles g-1 of product. The large majority ( > 95%) of particles in products surveyed were less than the 300 μm minimum diameter, indicating that previous environmental surveys could be underestimating microplastic contamination. To account for smaller particles as well as microfibers from synthetic textiles, we strongly recommend that future surveys consider methods that materials < 300 μm in diameter.

Do CSR Messages Resonate? Examining Public Reactions to Firms’ CSR Efforts on Social Media

Abstract: We posit a key goal of firms’ corporate social responsibility (CSR) efforts is to influence reputation through carefully crafted communicative practices. This trend has accelerated with the rise of social media such as Twitter and Facebook, which are essentially public message networks that organizations are leveraging to engage with concerned audiences. Given the large number of messages sent on these sites, only some will be effective and achieve broad public resonance. Building on signaling theory, this paper asks whether and how messages conveying CSR-related topics resonate with the public and, if so, which CSR topics and signal qualities are most effective. We test our hypotheses using data on public reactions to Fortune 500 companies’ CSR-focused Twitter feeds, using the retweeting (sharing) of firms’ messages as a proxy for public resonance. We find resonance is positively associated with messages that convey CSR topics such as the environment or education, those that make the topic explicit through use of hashtags, and those that tap into existing social movement discussions.

Gene expression profiling of intestinal regeneration in the sea cucumber

Abstract: Among deuterostomes, the regenerative potential is maximally expressed in echinoderms, animals that can quickly replace most injured organs. In particular, sea cucumbers are excellent models for studying organ regeneration since they regenerate their digestive tract after evisceration. However, echinoderms have been sidelined in modern regeneration studies partially because of the lack of genome-wide profiling approaches afforded by modern genomic tools. For the last decade, our laboratory has been using the sea cucumber Holothuria glaberrima to dissect the cellular and molecular events that allow for such amazing regenerative processes. We have already established an EST database obtained from cDNA libraries of normal and regenerating intestine at two different regeneration stages. This database now has over 7000 sequences. In the present work we used a custom-made microchip from Agilent with 60-mer probes for these ESTs, to determine the gene expression profile during intestinal regeneration. Here we compared the expression profile of animals at three different intestinal regeneration stages (3-, 7- and 14-days post evisceration) against the profile from normal (uneviscerated) intestines. The number of differentially expressed probes ranged from 70% at p < 0.05 to 39% at p < 0.001. Clustering analyses show specific profiles of expression for early (first week) and late (second week) regeneration stages. We used semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) to validate the expression profile of fifteen microarray detected differentially expressed genes which resulted in over 86% concordance between both techniques. Most of the differentially expressed ESTs showed no clear similarity to sequences in the databases and might represent novel genes associated with regeneration. However, other ESTs were similar to genes known to be involved in regeneration-related processes, wound healing, cell proliferation, differentiation, morphological plasticity, cell survival, stress response, immune challenge, and neoplastic transformation. Among those that have been validated, cytoskeletal genes, such as actins, and developmental genes, such as Wnt and Hox genes, show interesting expression profiles during regeneration. Our findings set the base for future studies into the molecular basis of intestinal regeneration. Moreover, it advances the use of echinoderms in regenerative biology, animals that because of their amazing properties and their key evolutionary position, might provide important clues to the genetic basis of regenerative processes.

Methane Emissions of Rice Increased by Elevated Carbon Dioxide and Temperature

Abstract: Methane (CH 4 ) effluxes by paddy-culture rice (Oryza saliva L.) contribute about 16% of the total anthropogenic emissions. Since radiative forcing of CH 4 at current atmospheric concentrations is 21 times greater on a per mole basis than that of carbon dioxide (CO 2 ), it is imperative that the impact of global change on rice CH 4 emissions be evaluated. Rice (cv. IR72) was planted in sunlit, closed-circulation, controlled-environment chambers in which CH 4 efflux densities were measured daily. The CO 2 concentration was maintained at either 330 or 660 μmol mol -1 . Air temperatures were controlled to daily maxima and minima of 32/23, 35/26, and 38/29°C at each CO 2 treatment. Emissions of CH 4 each day were determined during a 4-h period after venting and resealing the chambers at 0800 h. Diurnal CH 4 effluxes on 77, 98, and 119 d after planting (DAP) were obtained similarly at 4-h intervals. Emissions over four-plant hills and over flooded bare soil were measured at 53, 63, and 100 DAP. Emissions were negligible before 40 DAP. Thereafter, emissions were observed first in high-CO 2 , high-temperature treatments and reached a sustained maximum efflux density of about 7 mg m -2 h -1 (0.17 g m -2 d -1 ) near the end of the growing season. Total seasonal CH 4 emission was fourfold greater for high-CO 2 , high-temperature treatments than for the low-CO 2 , low-temperature treatment, probably due to more root sloughing or exudates, since about sixfold more acetate was found in the soil at 71 DAP. Both rising CO 2 and increasing temperatures could lead to a positive feedback on global warming by increasing the emissions of CH 4 from rice.