Bioassessment of the West Fork of the White River, Northwest Arkansas

The West Fork-White River has been and continues to be an important water resource for northwest Arkansas. It is used recreationally for fishing and swimming, agriculturally as a source of water for livestock and irrigation of crops, it is mined for gravel, used as a receiving stream for municipal wastewater effluent, and contributes to Beaver Lake which provides water for treatment and distribution to most of northwest Arkansas. While these uses have benefited a large segment of the Arkansas population, they have also contributed to the decline in environmental quality of the river. To facilitate the development of appropriate management protocols and assess restoration potential, we provided a biological assessment of the West ForkWhite River to complement studies of its physical and chemical properties. This holistic evaluation can be used presently, and to track changes in the environmental quality of the river in the future

Interview with J. Arthur Brown

In this interview with Michael Cooke, J. Arthur Brown (1914-1988) discusses his experience at Avery Institute and later the Progressive Democratic Party. Mr. Brown details the influence the Avery Institute had on shaping his outlook on black equality and fostering his interest in politics, as well as the NAACP’s involvement in the Civil Rights Movement in South Carolina.. He discusses his involvement with the Progressive Democratic Party and their influence on the black community, pivotal cases of Brown vs. The Board of Education, and his experiences with Judge Waties Waring

Distribution of Fish Within Headwater Riffles of the Illinois River System, Washington County, Arkansas

Quantitative sampling of fish was performed in five headwater riffles of the Illinois River System, Washington County, Arkansas during low flow conditions. This study revealed differing fish species composition, biomass and feeding guild segregation between head and tail riffle reaches in 1st through 3rd order. Thirty species representing 10 families were identified. Of this number, darters (Percidae), sculpins (Cottidae), madtoms (Ictaluridae), and central stonerollers (Campostoma anomalum) (Cyprinidae) comprised 67 to 98 percent of riffle head populations. Fish biomass was greater for riffle head areas (0.58-6.6/0.28-2.0 g/m2 ) within sectivores and herbivores dominating. Total fish numbers decreased from riffleheads to tails, while number of species increased. Dominant fish groups in tail areas were minnows (Cyprinidae), darters (Percidae), and sunfishes (Centrarchidae). Feeding guild fish groups in tail areas were predominately insectivore and insectivore-piscivore. Stomach analysis of Cottus carolinae, the dominant headwater riffle predator, indicated selective feeding of macrobenthic invertebrates and fish based on size class. Abundance of herbivore and insectivore fishes in riffles, particularly head reaches, suggests a correlation with positive rheotaxic behavior, microhabitat preference or abundance of macrobenthic invertebrate populations

Aquatic Macrophytes of Two Small Northwest Arkansas Reservoirs

Lake Fayetteville and Lake Wedington are small reservoirs of about the same size and age that are located in northwestern Arkansas. We collected macrophytes from eleven transects around each reservoir in the autumn of 1993. Justicia (waterwillow), Typha (cat-tail), Scirpus (bulrush), Potamogeton (pondweed), and Zannichellia (horned pondweed) occur in both reservoirs. Justicia occurs most commonly in both reservoirs. The macrophytes of Lake Wedington are organized in a characteristic zonation pattern with bands from shore toward open water of emergent, floating-leaved, then submersed macrophytes. Macrophyte zonation was not as evident in Lake Fayetteville because of the low occurrence of floating leaved and submersed macrophytes in1993. Early studies of Lake Wedington found that the dominant macrophytes were Cyperus, Echinochloa, Lotus, and Sagittaria, all of which were absent during this study. Potamogeton, Scirpus, and Typha were also found to be dominant during 1952 studies, but occurred in lesser amounts in the current study. Previous studies (1956, 1967, 1977) on Lake Fayetteville stated that Sagittaria and Nelumbo were dominant macrophytes, but we found none in1993. Juncus, Potamogeton, Scirpus, and Typha were common in the early studies but occurred infrequently in our collections. Macrophyte composition in Lake Fayetteville in 1993 was attributable to an herbicide application that occurred in spring, 1992. As for the changes in Lake Wedington, we assume that the Justicia has out-competed those macrophytes that were in the reservoir in1952, or that normal lake ontogeny during the intervening 40 years has altered habitat conditions to now favor Justicia

Development Strategy of the Facility Traditional Fish Landing Sites (Mediator) in the Village of West Bagan, Bangko Subdistrict, Rokan Hilir, Riau Province

Village of West Bagan is a village with a population of the second largest fishermen in the district of Bangko, RokanHilir, Riau Province. Fishermen of the West Bagan village, land and sell their catch in private mediators. However, the facilities available are not enough to meet the needs of fishing supplies consisting of fuel, fresh water and ice. Therefore, this research with survey method was undertaken to obtain the development strategy of the facility by using SWOT analysis. From 9 units mediator were still active, taken 3 units mediator as representatives of large, medium, and small category namely are consecutevely Jumadi mediator, Lausi mediator, dan Asmara mediator. Based on SWOT analysis has been done on each of the mediators obtained one most likely to be develop is mediator Jumadi. In the diagram strategy, mediator Jumadi located in quadrant I with the highest coordinate value, which is a provitable situation. Recommendations strategyis progressive, which means the mediator has the opportunity and the power that can take advantage of existing opportunities. The strategy applied in this condition is to support aggressive growth policy

Cell clustering mediated by the adhesion protein PVRL4 is necessary for alpha6beta4 integrin-promoted ferroptosis resistance in matrix-detached cells

Ferroptosis is an iron-dependent form of programmed cell death characterized by the accumulation of lipid-targeting reactive oxygen species that kill cells by damaging their plasma membrane. The lipid-repair enzyme glutathione peroxidase 4 (GPX4) protects against this oxidative damage and enables cells to resist ferroptosis. Recent work has revealed that matrix-detached carcinoma cells can be susceptible to ferroptosis and that they can evade this fate through the signaling properties of the alpha6beta4 integrin, which sustains GPX4 expression. Although these findings on ferroptosis are provocative, they differ from those in previous studies indicating that matrix-detached cells are prone to apoptosis, via a process referred to as anoikis. In an effort to reconcile these discrepant findings, here we observed that matrix-detached epithelial and carcinoma cells cluster spontaneously via a mechanism that involves the cell adhesion protein PVRL4 (also known as Nectin-4). We found that this clustering process allows these cells to survive by stimulating a PVRL4/alpha6beta4/Src signaling axis that sustains GPX4 expression and buffers against lipid peroxidation. In the absence of alpha6beta4, PVRL4-mediated clustering induced an increase in lipid peroxidation that was sufficient for triggering ferroptosis. When the clustering was inhibited, single cells did not exhibit a significant increase in lipid peroxidation in the absence of alpha6beta4, and they were more susceptible to apoptosis than to ferroptosis. These results indicate that ferroptosis induction depends on cell clustering in matrix-detached cells that lack alpha6beta4 and imply that the fate of matrix-detached cells can be determined by the state of their cell-cell interactions

Review of Downscaling Methodologies for Africa Climate Applications

Downscaling is the term used to describe the various methods used to translate the climate projections from coarse resolution GCMs to finer resolutions deemed more useful for assessing impacts. Projections of future climate are produced using complex, coupled atmosphere-ocean models (GCMs). The GCMs are most reliable at the continental scale. Due to the inherent uncertainty of the climate system and the inevitable existence of model errors, multi-model ensembling is the recommended approach for characterizing expected climate changes. As downscaling is dependent on the ability of GCMs to successfully project the climate change signal, it is limited to where that signal is clear. Assessments of climate change in Africa indicate some consensus of reduced winter rainfall in southern Africa, increased annual rainfall in east Africa and uncertainty for the rest of Africa. Selection of GCMs that "do better" over Africa, or any region, is difficult and probably not warranted, given the general parity in model skill and the difficulty in identifying which models are more skillful. Ensemble means or medians offer the highest level of projection accuracy. Downscaling approaches are generally categorized as dynamical, using regional climate models, and statistical, using empirical relationships. However, dynamical downscaling often includes statistical modeling in the form of "bias correction." Dynamical downscaling is useful for incorporating topographic features, such as strong orography, and land use and vegetation. It is recommended where those features play a significant role in regional climate. However, computational time and the uncertainties that accompany complex models outweigh the benefits of dynamical downscaling where these features are not significant. The spatial resolution that can be achieved is on the order of tens of kilometers. Statistical downscaling is simpler and more efficient than dynamical downscaling. It is preferred where estimates of specific variables, especially at point locations, are sought for input to sector models (e.g., hydrologic models) or decision making. However, statistical modeling can mask a true understanding of regional climate dynamics and estimates may be overconfident. In summary, downscaling is best understood as an attempt to increase the understanding of climate change influences at the regional scale. In that context, a variety of methodologies should be explored, using all tools possible to increase that understanding. A set of "Best Practices" is recommended for pursuing this effort