Riparian understory dynamics and relationship to dams on the Elwha River, Washington

Dams alter the dynamics inherent to river systems by displacing natural hydrologic and sediment regimes, which can fundamentally alter riparian ecosystem function. However, with better understanding of how dams negatively impact river systems, and as many dams approach the end of their lifespan, dam removal is being used to facilitate ecosystem restoration. Whereas researchers have successfully illustrated the negative impacts dams have on biological communities, the long-term ecological implications of dam removal are not well understood. At present, two dams are being removed along the Elwha River (Washington, USA), providing a valuable window for ecological studies concerning the effects of dams, and their removal, on biotic communities. In this study I described plant community dynamics along the twice-dammed Elwha River for use as a baseline in assessing the long-term effects of dam removal on this river system. I determined the relationships between understory and overstory riparian plant communities and how they vary across geomorphic landforms relative to the dams over a five-year period (2005 to 2010). I also evaluated the relative utility of under- and overstory species as indicators of plant community type, reach location and geomorphic landform. Vegetation and environmental surveys were conducted in 2005 and 2010 on 100-m² plots located along 15 perpendicular transects on river reaches above, below and between the Glines Canyon and Elwha dams. I used multivariate analyses to define plant communities along transects by assessing species composition within each plot (via frequency and abundance of species), and characterized their distribution. I used a general linear models approach to assess compositional change in plant communities along river reaches over the five-year interval to determine the stability of understory and overstory plant communities. Finally, I used an indicator species analysis to examine the distributions of individual plant species. I found that plant community composition along the Elwha River was heavily influenced by the distribution of geomorphic landforms. Physical factors (e.g. soil depth, substrate size, ground cover) were strongly correlated with longitudinal location and geomorphic position. River reaches delineated by the dams had markedly different plant communities. The reach between both dams had the fewer early successional communities associated with younger landforms, perhaps due to sediment starvation; this suggests the dams have played a role in plant community distribution. In reaches above and below the dams there were greater differences between understory and overstory community composition as compared to the middle reach. Understory communities were less stable, meaning they had greater species compositional changes over time, compared to overstory communities, which were more stable. These data suggest the dams may have attenuated natural disturbance events in the middle reach. Overstory species were the more useful for indicating the overall plant community, however, understory species were more reliable indicators of reach location understory than the overstory. These data provide a useful baseline for post-removal comparisons evaluating the long-term effects of dam removal on the Elwha River. My results concur with others that have suggested that reaches downstream of the dams will be most affected post- removal by the influx of sediments from the former reservoirs. I predict that, in addition to the reestablishment of younger landforms, dam removal will result in an increase of early-sere, disturbance-tolerant communities in downstream reaches. Also I anticipate that the stability of the understory and overstory communities will become more reminiscent of natural conditions (more stable overstory than understory) along all reaches. I also suggest that understory species not be neglected from indicator analyses, as they can be accurate, even exclusive, indicators for factors such as plant community type, geomorphic landform and reach location --Document

Dinámicas de la guianza turística antes, durante y después de la pandemia COVID-19 en la ciudad de Cuenca, Ecuador

La presente investigación analiza las dinámicas en el sector de la guianza turística en el escenario de la pandemia COVID-19 en la ciudad de Cuenca, Ecuador. Dicho estudio se fundamenta sobre la teoría de la incertidumbre en el campo de las ciencias sociales con relación a la pandemia COVID-19, la misma que produjo una crisis en los diferentes sectores productivos creando diversos escenarios de incertidumbre. El embate de la pandemia COVID-19 fue devastador especialmente para la industria del turismo y sus diferentes campos laborales, entre ellos, la guianza turística; imposibilitando de esta manera el desarrollo normal de sus actividades. Por lo tanto, con el fin de identificar el campo de acción de los guías de turismo antes, durante y después de la pandemia, se indagó en primera instancia sobre su perfil profesional, luego sobre su comportamiento antes y durante la crisis sanitaria y finalmente sobre sus proyecciones frente a retos similares en el futuro. El enfoque de la investigación es de tipo cualitativo de alcance exploratorio y corte transversal, apoyado en entrevistas y grupos focales. Se evidencia el abandono por parte de la autoridad de turismo a dichos profesionales, altos niveles de informalidad y la versatilidad del guía de turismo en función a sus habilidades. Además, sobresale la capacidad para adaptarse y afrontar diferentes desafíos en la etapa post-pandemia. Palabras clave: dinámicas, incertidumbre, guía de turismo, COVID-19The present research analyzes the dynamics in the tourist guide sector in the scenario of the COVID-19 pandemic in the city of Cuenca, Ecuador. This study is based on the theory of uncertainty in the field of social sciences in relation to the COVID-19 pandemic, which produced a crisis in the different productive sectors, creating diverse scenarios of uncertainty. The onslaught of the COVID-19 pandemic was devastating, especially for the tourism industry and its different fields of work, among them, tourist guiding, thus making the normal development of its activities impossible. Therefore, in order to identify the field of action of tourist guides before, during and after the pandemic, we first inquired about their professional profile, then about their behavior before and during the health crisis, and finally about their projections in the face of similar challenges in the future. The research approach is qualitative, exploratory in scope and cross-sectional, supported by interviews and focus groups. It shows the abandonment of these professionals by the tourism authority, high levels of informality and the versatility of the tour guide in terms of his or her skills. In addition, the ability to adapt and face different challenges in the post-pandemic stage stands out. Keywords: dynamics, uncertainty, tour guide, COVID-190000-0003-3581-002

Identification of global inhibitors of cellular glycosylation

Small molecule inhibitors of glycosylation enzymes are valuable tools for dissecting glycan functions and potential drug candidates. Screening for inhibitors of glycosyltransferases are mainly performed by in vitro enzyme assays with difficulties moving candidates to cells and animals. Here, we circumvent this by employing a cell-based screening assay using glycoengineered cells expressing tailored reporter glycoproteins. We focused on GalNAc-type O-glycosylation and selected the GalNAc-T11 isoenzyme that selectively glycosylates endocytic low-density lipoprotein receptor (LDLR)-related proteins as targets. Our screen of a limited small molecule compound library did not identify selective inhibitors of GalNAc-T11, however, we identify two compounds that broadly inhibited Golgi-localized glycosylation processes. These compounds mediate the reversible fragmentation of the Golgi system without affecting secretion. We demonstrate how these inhibitors can be used to manipulate glycosylation in cells to induce expression of truncated O-glycans and augment binding of cancer-specific Tn-glycoprotein antibodies and to inhibit expression of heparan sulfate and binding and infection of SARS-CoV-2

Global asthma prevalence in adults: findings from the cross-sectional world health survey

<p>Abstract</p> <p>Background</p> <p>Asthma is a major cause of disability, health resource utilization and poor quality of life world-wide. We set out to generate estimates of the global burden of asthma in adults, which may inform the development of strategies to address this common disease.</p> <p>Methods</p> <p>The World Health Survey (WHS) was developed and implemented by the World Health Organization in 2002-2003. A total of 178,215 individuals from 70 countries aged 18 to 45 years responded to questions related to asthma and related symptoms. The prevalence of asthma was based on responses to questions relating to self-reported doctor diagnosed asthma, clinical/treated asthma, and wheezing in the last 12 months.</p> <p>Results</p> <p>The global prevalence rates of doctor diagnosed asthma, clinical/treated asthma and wheezing in adults were 4.3%, 4.5%, and 8.6% respectively, and varied by as much as 21-fold amongst the 70 countries. Australia reported the highest rate of doctor diagnosed, clinical/treated asthma, and wheezing (21.0%, 21.5%, and 27.4%). Amongst those with clinical/treated asthma, almost 24% were current smokers, half reported wheezing, and 20% had never been treated for asthma.</p> <p>Conclusions</p> <p>This study provides a global estimate of the burden of asthma in adults, and suggests that asthma continues to be a major public health concern worldwide. The high prevalence of smoking remains a major barrier to combating the global burden of asthma. While the highest prevalence rates were observed in resource-rich countries, resource-poor nations were also significantly affected, posing a barrier to development as it stretches further the demands of non-communicable diseases.</p

Functional overlap of microtubule assembly factors in chromatin-promoted spindle assembly

Author Posting. © American Society for Cell Biology, 2009. This article is posted here by permission of American Society for Cell Biology for personal use, not for redistribution. The definitive version was published in Molecular Biology of the Cell 20 (2009): 2766-2773, doi:10.1091/mbc.E09-01-0043.Distinct pathways from centrosomes and chromatin are thought to contribute in parallel to microtubule nucleation and stabilization during animal cell mitotic spindle assembly, but their full mechanisms are not known. We investigated the function of three proposed nucleation/stabilization factors, TPX2, {gamma}-tubulin and XMAP215, in chromatin-promoted assembly of anastral spindles in Xenopus laevis egg extract. In addition to conventional depletion-add back experiments, we tested whether factors could substitute for each other, indicative of functional redundancy. All three factors were required for microtubule polymerization and bipolar spindle assembly around chromatin beads. Depletion of TPX2 was partially rescued by the addition of excess XMAP215 or EB1, or inhibiting MCAK (a Kinesin-13). Depletion of either {gamma}-tubulin or XMAP215 was partially rescued by adding back XMAP215, but not by adding any of the other factors. These data reveal functional redundancy between specific assembly factors in the chromatin pathway, suggesting individual proteins or pathways commonly viewed to be essential may not have entirely unique functions.This work was supported by the American Cancer Society (grant PF0711401 to T. J. Maresca), the National Cancer Institute (grant CA078048-09 to T. J. Mitchison) and the National Institutes of Health (grant F32GM080049 to J. C. Gatlin and grant GM24364 to E. D. Salmon)

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

On the issue of transparency and reproducibility in nanomedicine.

Following our call to join in the discussion over the suitability of implementing a reporting checklist for bio-nano papers, the community responds

Graphic Notation of Vulnerability

The project represents the various sensory experiences encountered while walking along the Huron River from the Medical Center to the Argo Dam. Using graphic notation, I documented and represented the sense of vulnerability as I moved along the river, specificially observing shadows, confinement and supervision--supervision that effectively prevents vulnerability from assault. I chose graphic notation that was intended to mimic musical notation to illustrate the modulation of senses as one moves along the river, specifically the building and releasing of tension. I employed a five-line staff, using notation of vulnerability much like the musical symbols of crecendo and diminuendo to represent the modulation of the senses.http://deepblue.lib.umich.edu/bitstream/2027.42/120338/1/Clausen_GraphicNotationOfVulnerability.pd