A new bond fluctuation method for a polymer undergoing gel electrophoresis

We present a new computational methodology for the investigation of gel electrophoresis of polyelectrolytes. We have developed the method initially to incorporate sliding motion of tight parts of a polymer pulled by an electric field into the bond fluctuation method (BFM). Such motion due to tensile force over distances much larger than the persistent length is realized by non-local movement of a slack monomer at an either end of the tight part. The latter movement is introduced stochastically. This new BFM overcomes the well-known difficulty in the conventional BFM that polymers are trapped by gel fibers in relatively large fields. At the same time it also reproduces properly equilibrium properties of a polymer in a vanishing filed limit. The new BFM thus turns out an efficient computational method to study gel electrophoresis in a wide range of the electric field strength.Comment: 15 pages, 11 figure

Statistical Analysis of Factors Influencing Corrosion in Concrete Structures

The use of mathematical and statistical models has allowed the description of the behavior of many natural phenomena. However, their application in civil engineering particularly, for the analysis of the corrosion behavior, has been overlooked in recent studies. In the present work, a factorial analysis with subdivided parcels design were conducted to evaluate the corrosion rate behavior of arrangements of protected and not protected steel bars found in reinforced concrete specimens subject to two different aggressive media. The results showed that, in comparison to sulphate ions, the effect of chloride ions on the corrosion rate was not statistically significant. In the same way, protected and not protected segments on the steel bars (i.e., steel bar condition) did not have a significant effect on the corrosion rate. The only factor found to significantly affect the corrosion rate was the variability of the beam fabrication process (i.e., beam factor)

Adaptation and Validation of QUick, Easy, New, CHEap, and Reproducible (QUENCHER) Antioxidant Capacity Assays in Model Products Obtained from Residual Wine Pomace

Evaluation of the total antioxidant capacity of solid matrices without extraction steps is a very interesting alternative for food researchers and also for food industries. These methodologies have been denominated QUENCHER from QUick, Easy, New, CHEap, and Reproducible assays. To demonstrate and highlight the validity of QUENCHER (Q) methods, values of Q-method validation were showed for the first time, and they were tested with products of well-known different chemical properties. Furthermore, new QUENCHER assays to measure scavenging capacity against superoxide, hydroxyl, and lipid peroxyl radicals were developed. Calibration models showed good linearity (R2 > 0.995), proportionality and precision (CV < 6.5%), and acceptable detection limits (<20.4 nmol Trolox equiv). The presence of ethanol in the reaction medium gave antioxidant capacity values significantly different from those obtained with water. The dilution of samples with powdered cellulose was discouraged because possible interferences with some of the matrices analyzed may take place.The autonomous government of Castilla y León (Project BU268A11-2

Transportation Corridors in Arizona and Mexico and Pronghorn: Case Studies

We reviewed 13 case studies from Arizona and Sonora, Mexico, on the effects of transportation corridors on pronghorn (Antiocapra americana). What do we know and what can we do about it? Since the mid-1900s, naturalists/biologists have known that transportation corridors such as highway and railroad rights-of-way can affect pronghorn populations. Beginning in 1983, we have radiomarked ~250 adult pronghorn across Arizona and northern Sonora, Mexico to assess the effects of transportation corridors on various populations. During this over 20-year period, we conducted 3 studies, 1 in Sonora, Mexico, on the endangered Sonoran pronghorn (A. a. sonoriensis) and 10 studies in central and northern Arizona on other subspecies. With &gt;34,000 radio locations, we report on the documented effects of transportation corridors from these 13 case studies. Transportation corridor effects varied by type of corridor (number of lanes, fenced vs. unfenced, and presumably by traffic volume). Pronghorn readily crossed paved, unfenced roadways with low traffic volume, occasionally crossed paved, fenced 2-lane highways, but only in certain situations, but did not cross high-volume highways or divided interstates. Railroad rights--of-way also isolated pronghorn herds and fragmented habitat. Six mitigation ideas are presented and discussed that could improve the likelihood of pronghorn crossings. The current “wildlife missing linkages” project in Arizona is attempting to identify fragmentation of habitat across the state due to transportation corridors and plan for remedies to lessen the impact of transportation on many species of wildlife, including pronghorn. We conclude that additional research on mitigation features is warranted

Repeat Organic Dust Exposure–Induced Monocyte Inflammation is Associated with Protein Kinase C Activity

Background: Organic dust exposure results in an inflammatory response that attenuates over time, but repetitive exposures can result in chronic respiratory diseases. Mechanisms underlying this modulated response are not clear. Objective: This study investigated the effects of repeat versus single organic dust exposure–induced inflammatory mediators and protein kinase C (PKC) activity in monocytes. Methods: Settled organic dust was obtained from swine confinement facilities. Promonocytic THP-1 cells and human peripheral blood monocytes were pretreated with or without dust extract and then restimulated. Culture supernatants were evaluated for TNF-α, IL-6, CXCL8, and IL-10. Responses were compared with endotoxin-depleted dust, LPS, and peptidoglycan. PKC isoform (α, δ, ε, ζ) activation was evaluated by direct kinase activity. PKC isoform inhibitors’ effects on TNF-a secretion were studied. Results: Single exposure to organic dust stimulated monocyte secretion of TNF-α, IL-6, CXCL8, and IL-10 compared with unstimulated cells. TNF-α and IL-6 were diminished in pretreated cells restimulated with dust. Secretion of CXCL8 and IL-10 remained persistently elevated. TNF-α responses were retained after marked depletion of endotoxin. Dust exposure induced significant PKC α, δ, ε, and ζ activation, peaking at 30 to 60 minutes. PKC isoform activation was attenuated in repeat exposed cells. Inhibition of PKCa and PKCe reduced dust-induced TNF-α secretion. Conclusion: Repeat organic dust exposure modulated inflammatory mediator production in monocytes independent of endotoxin. The inability of PKC to be reactivated may account for this observation. Clinical implications: Targeting PKC and specific mediators associated with repetitive organic dust exposure may result in novel therapeutic strategies

Diets of Desert Mule Deer

We studied the diets of desert mule deer (Odocoileus hemionus crooki Mearns) at 3 sites in Arizona and collated this information with that of previous diet studies of desert mule deer across their range in the United States. We documented 96 browse, 69 forb, 14 succulent, and 6 grass species that each constituted ≥ 1% of the diet during ≥ 1 season. The occurrence of individual plant species varied spatially and temporally. Changes in nutrient levels and climatic influence on relative availability and phenology of plant species likely influenced diet. Desert mule deer rely heavily on browse and forbes, which make up the majority of their diet (\u3e 90%). Grasses and succulents were generally \u3c 5% of the diet. Rangeland managers should strive to keep desert rangelands productive with a diversity of forage so animals have opportunities to exercise free choice of diet