Soil Compaction Study of 20 Timber-harvest Units on the Ouachita National Forest

A soil compaction study was performed on 20 timber harvest units on both rocky (15-35 % by volume gravel) and non-rocky (<15 % by volume gravel) surface soils of the Ouachita National Forest in Arkansas, to determine if these areas met the USDA Forest Service Southern Region (R8) soil quality standards for compaction and affected area extent. The compaction standard states bulk density cannot increase more than 15 % from its natural (undisturbed) level and not more than 15 % of an activity area can be adversely affected. Eight of the study units exceeded this standard. These eight units generally contained less than 15 % rock fragments in the top 8 inches (20 cm) of soil, and seven of the eight had been harvested during the moist season (December-June) using rubber tire skidders. The non-rocky soil units, when harvested during the dry season (July-November), resulted in about 20-50 % less compaction than when harvested during the moist season. Non-rocky soils with a sandy loam surface tended to compact less during dry season but more during moist season equipment operation than the non-rocky loam or silt loam soils. Compaction also averaged about 30-50 % less on the rocky soils than on non-rocky soils. On the rocky soils, logging equipment operation during either the dry or moist season did not show a difference, and only native surface roads and log decks tended to have a greater than 15 % bulk density increase. Compaction due to timber harvest activities that had occurred at least 15-20 years earlier averaged about 9 % bulk density increase for the nonrocky soils and 7 % for the rocky soils, and indicated that partial recovery had occurred. An analysis of surface infiltration rates found that a 15 % density change resulted in more than 60 % reduction in infiltration. This study also found that a 15 % density change can be visually determined by change in soil structure

Forestry on the Island of Taiwan, ROC - The State of the Art

The forests of Taiwan vary from lush subtropical vegetation to subalpine coniferous associations. Topography is exceedingly rugged, and stands border on the verge of silvicultural inoperability. In the 1950s and 1960s, the wood products industry in the Republic of China was of paramount importance; the production of high-quality sawtimber from old-growth cypress (Cupressaceae) stands provided the financial capital that built one of the most prosperous national economies in the modern world. In the 1980s, forestry in Taiwan is a curious blend of old methods and new technologies, as modern silvicultural practices are used to reforest cutover cypress stands, to harvest and reproduce remaining old-growth stands, and to expand the silvicultural importance of other forest types on the island. Many applied research efforts would be promising in application to the forests of Taiwan, such as long-term studies of silvicultural practices on water quality, methodology of natural regeneration applied to cypress and Taiwania cryptomerioides (Taxodiaceae), uneven-aged regulation applied to bamboo, Phyllostachys pubescens (Bambusaceae), growth and yield in coniferous plantations, effectiveness of modern herbicides in controlling competition in young plantations, and application of contemporary economic assessments in the evaluation of silvicultural alternatives

Dual-Mode and Label-Free Detection of Exosomes from Plasma Using an Electrochemical Quartz Crystal Microbalance with Dissipation Monitoring

The biomolecular contents of extracellular vesicles, such as exosomes, have been shown to be crucial in intercellular communication and disease propagation. As a result, there has been a recent surge in the exploration of novel biosensing platforms that can sensitively and specifically detect exosomal content such as proteins and nucleic acids, with a view toward application in diagnostic assays. Here, we demonstrate dual-mode and label-free detection of plasma exosomes using an electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D). The platform adopts a direct immunosensing approach to effectively capture exosomes via their surface protein expression of CD63. By combining QCM-D with a tandem in situ electrochemical impedance spectroscopy measurement, we are able to demonstrate relationships between mass, viscoelasticity and impedance inducing properties of each functional layer and analyte. In addition to lowering the limit of detection (by a factor of 2-4) to 6.71 × 107 exosome-sized particles (ESP) per mL in 25% v/v serum, the synergy between dissipation and impedance response introduces improved sensing specificity by offering further distinction between soft and rigid analytes, thereby promoting EQCM-D as an important technique for exosome analysis

Recent developments in biosensing methods for extracellular vesicle protein characterization

Research into extracellular vesicles (EVs) has grown significantly over the last few decades with EVs being widely regarded as a source of biomarkers for human health and disease with massive clinical potential. Secreted by every cell type in the body, EVs report on the internal cellular conditions across all tissue types. Their presence in readily accessible biofluids makes the potential of EV biosensing highly attractive as a noninvasive diagnostic platform via liquid biopsies. However, their small size (50-250 nm), inherent heterogeneity, and the complexity of the native biofluids introduce challenges for effective characterization, thus, limiting their clinical utility. This has led to a surge in the development of various novel EV biosensing techniques, with capabilities beyond those of conventional methods that have been directly transferred from cell biology. In this review, key detection principles used for EV biosensing are summarized, with a focus on some of the most recent and fundamental developments in the field over the last 5 years. This article is categorized under: Diagnostic Tools > Biosensing Diagnostic Tools > In Vitro Nanoparticle-Based Sensing

Silica Inverse Opal Nanostructured Sensors for Enhanced Immunodetection of Extracellular Vesicles by Quartz Crystal Microbalance with Dissipation Monitoring

Extracellular vesicles (EVs) are nanosized circulating assemblies that contain biomarkers considered promising for early diagnosis within neurology, cardiology, and oncology. Recently, acoustic wave biosensors, in particular based on quartz crystal microbalance with dissipation monitoring (QCM-D), have emerged as a sensitive, label-free, and selective EV characterization platform. A rational approach to further improving sensing detection limits relies on the nanostructuration of the sensor surfaces. To this end, inorganic inverse opals (IOs) derived from colloidal self-assembly present a highly tunable and scalable nanoarchitecture of suitable feature sizes and surface chemistry. This work systematically investigates their use in two-dimensional (2D) and three-dimensional (3D) for enhanced QCM-D EV detection. Precise tuning of the architecture parameters delivered improvements in detection performance to sensitivities as low as 6.24 × 107 particles/mL. Our findings emphasize that attempts to enhance acoustic immunosensing via increasing the surface area by 3D nanostructuration need to be carefully analyzed in order to exclude solvent and artifact entrapment effects. Moreover, the use of 2D nanostructured electrodes to compartmentalize analyte anchoring presents a particularly promising design principle

The Ursinus Weekly, November 24, 1952

Fall play to be Dec. 5, 6; Ticket sale begins Dec. 1 • Bob Harry to play at senior formal • Freshman rep is sworn in by MSGA • Phys-eds get new teachers • Naval officer to speak here, Dec. 3 • Pre-legal group hears speaker, accepts three new members • Lantern goes to press today; Barbara Wagner designs cover • Messiah seats reserved for 100 students • Constitution changes begun by W.S.G.A. • About 100 students enjoy variety show • Lord Winterton to speak at first forum tomorrow • First Chest drive proceeds small; Two days remain • Help offered for grad study • SWC wins hunt sponsored by Y • Spirit group chooses words for dorm decoration prize • Editorials: Plea to 60 students; What\u27s wrong, men?; Brighter side • Letters to the editor • Two staff members enjoy play preview • Murky for the turkey • Dr. A. Rice attends Atlantic Union sessions • Dickinson hands Bears loss in grid final, 18-6 • Bakermen drop season closer, 6-0 • Former coach plays softball in Korea • Snell\u27s Belles close season by defeating Penn • Marge Merrifield elected captain • Women elect chairmen of table decoration committees • Chess club ties Lansdale • Chi Alpha organizes for Christmas worship service • Bus ads plan discussionhttps://digitalcommons.ursinus.edu/weekly/1507/thumbnail.jp

Pore Filling of Spiro-OMeTAD in Solid-State Dye-Sensitized Solar Cells Determined Via Optical Reflectometry

A simple strategy is presented to determine the pore-filling fraction of the hole-conductor 2,2-7,7-tetrakis-N,N-di-pmethoxyphenylamine-9,9-spirobifluorene (spiro-OMeTAD) into mesoporous photoanodes in solid-state dye-sensitized solar cells (ss-DSCs). Based on refractive index determination by the film’s reflectance spectra and using effective medium approximations the volume fractions of the constituent materials can be extracted, hence the pore-filling fraction quantified. This non-destructive method can be used with complete films and does not require detailed model assumptions. Pore-filling fractions of up to 80% are estimated for optimized solid-state DSC photoanodes, which is higher than that previously estimated by indirect methods. Additionally, transport and recombination lifetimes as a function of the pore-filling fraction are determined using photovoltage and photocurrent decay measurements. While extended electron lifetimes are observed with increasing pore-filling fractions, no trend is found in the transport kinetics. The data suggest that a pore-filling fraction of greater than 60% is necessary to achieve optimized performance in ss-DSCs. This degree of pore-filling is even achieved in 5 mu m thick mesoporous photoanodes. It is concluded that pore-filling is not a limiting factor in the fabrication of “thick” ss-DSCs with spiro-OMeTAD as the hole-conductor

The Ursinus Weekly, October 20, 1952

Helfferich to receive degree on Founders Day • MSGA rules breaks as illegal, customs to remain • Bloodmobile to come Wed. • Sorority rushees to open bids Friday • Newman Club hears speaker • Hutchison chosen to plan frosh show • Debating club meets • Varied plans made for Old Timers Day • Day study plans for fashion show; Initiates freshmen • Roberts, Geiger cast as leads in Fall production • Ten new members chosen by Lantern • Orsini to benefit by dance proceeds • Sturgis receives honor at ceremony • Varsity Club to hold dance • Carnival, Halloween ball planned by senior class • Pre-med honors Brownback • Editorials: Highest honor; Give blood • Campus Chest conducts poll • Chem society to visit Sun Oil • Juniors hold birch beer ball • Warren to address college students • Affair in Wisconsin • Etiquette part of frosh orientation • Student Union data released • Over 75 students attend Y retreat • Old Timers Day not new; Football stories of past • Ursinus viewed by freshman • Dr. Yost marks college boards; Unique marking system shown • Hockey team loses to E. Stroudsburg • Bears rout Haverford 19-0; Glock, Swett score fourth • Bakermen tie Mules 3-3 on Tait\u27s last minute goal • Swarthmore here on Alumni Day • Brodbeck and Curtis victors • Banner found • WAA holds reception for freshman womenhttps://digitalcommons.ursinus.edu/weekly/1502/thumbnail.jp

A Toolkit to Quantify Target Compounds in Thin-Layer-Chromatography Experiments

Thin-layer chromatography (TLC) is one of the basic analytical procedures in chemistry and allows the demonstration of various chemical principles in an educational setting. An often-overlooked aspect of TLC is the capability to quantify isolated target compounds in an unknown sample. Here, we present a suitable route to implement quantitative analysis in a lesson plan. We provide both a stand-alone software and an online webapp that allow students to obtain quantitative information from a developed TLC plate and present two suitable experiments, namely, the absorbance-based quantification of the colorant Sudan IV and the fluorescence-based quantification of rhodamine 6G, a fluorophore widely used in biotechnology. Students conduct TLC experiments following established protocols, take pictures of their TLC plates with mobile phones, and subsequently quantify the different compounds in the separate bands they observe