Cold Caustic Soda Pulp from Aspen Wood Some Facts on the Material Dissolved by the Process

The available literature on the cold caustic soda pulping process, the composition of aspen wood, the composition of spent liquor from other pulping processes, paper chromatographic methods suitable for the analysis of wood and pulp hydrolyzates, and the material removed from aspen wood by the cold caustic soda pulping process have been surveyed. Aspen wood hydrolyzates were analyzed using n-butanol: pyridine: water solvent system by paper chromatographic methods. Cold caustic soda pulp was prepared using a two hour soaking period at 25°c temperature, and a 24 gram per liter caustic soda solution with a wood to liquor ratio of 1:5.5. The prepared pulp hydrolyzate was also analyzed by paper chromatographic means. Experimental results indicated that glucose, xylose, mannose, and traces of galactose and arabionse were present in aspen wood, and that the cold caustic soda pulping process removed all sugars to varying degrees

The SERENDIP 2 SETI project: Current status

Over the past 30 years, interest in extraterrestrial intelligence has progressed from philosophical discussion to rigorous scientific endeavors attempting to make contact. Since it is impossible to assess the probability of success and the amount of telescope time needed for detection, Search for Extraterrestrial Intelligence (SETI) Projects are plagued with the problem of attaining the large amounts of time needed on the world's precious few large radio telescopes. To circumvent this problem, the Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations (SERENDIP) instrument operates autonomously in a piggyback mode utilizing whatever observing plan is chosen by the primary observer. In this way, large quantities of high-quality data can be collected in a cost-effective and unobtrusive manner. During normal operations, SERENDIP logs statistically significant events for further offline analysis. Due to the large number of terrestrial and near-space transmitters on earth, a major element of the SERENDIP project involves identifying and rejecting spurious signals from these sources. Another major element of the SERENDIP Project (as well as most other SETI efforts) is detecting extraterrestrial intelligence (ETI) signals. Events selected as candidate ETI signals are studied further in a targeted search program which utilizes between 24 to 48 hours of dedicated telescope time each year

A Simple, Rapid Method for Extracting Large Plasmid DNA from Bacteria

We are studying the lateral transfer of transmissible antibiotic resistance plasmids among stream bacteria impacted by fecal runoff from poultry and cattle. Such plasmids are typically large (ca. 40 – 100 kb) and occur in low copy numbers in the cell and have therefore typically been difficult to isolate and therefore to study. Traditional protocols, based upon variations of the standard alkaline-lysis method, are long (ca. 1 1/2 to 2 days) and difficult. Commercial kits designed for the isolation of Baterial Artificial Chromosomes (BACs) can be used and are an improvement; however, these are expensive and still require hours of sustained effort. We have adapted a method published by Rondon et al. (1999), originally designed for the isolation of BAC DNA, for the rapid isolation of large plasmid DNA. In this method, lysis and alkaline denaturation steps are combined, incubation steps are vastly reduced, proteins are removed via a simple ammonium acetate/chloroform step, and the DNA precipitated using a plyethylene glycol/NaCl step. No ethanol precipitation is required. If additional purification is required, extracted DNA can be further processed through a Qiagen Plasmid Mini or Midi column (Qiagen Inc., Valencia CA). The method is rapid (under 1 hour), easy, very inexpensive and has been reliably used by undergraduate students to isolate large (up to 200 kb) native plasmids from a variety of both Gram-positive and Gram-negative genera including _Shigella_, _Klebsiella_, _E. coli_, _Pseudomonas_, _Bacills_, _Streptococcus_, _Staphylococcus_, and _Enterococcus_, as well as BACs from _E. coli_. The protocol is simple and reliable enough to be used for the rapid large-scale visualization of native plasmids and we have used it to visualize and isolate DNA from hundreds of multidrug resistance plasmids exogenously captured from stream sediments, soils, and beach sands.&#xa

Pyramidal Atoms: Berylliumlike Hollow States

Based on the idea that four excited electrons arrange themselves around the nucleus in the corners of a pyramid in order to minimize their mutual repulsion, we present an analytical model of quadruply excited states. The model shows excellent comparison with ab initio results and provides a clear physical picture of the intrinsic motion of the four electrons. The model is used to predict configuration-mixing fractions and spectra of these highly correlated states.Comment: 4 pages, 2 figure

Serum PCB levels and congener profiles among teachers in PCB-containing schools: a pilot study

<p>Abstract</p> <p>Background</p> <p>PCB contamination in the built environment may result from the release of PCBs from building materials. The significance of this contamination as a pathway of human exposure is not well-characterized, however. This research compared the serum PCB concentrations, and congener profiles between 18 teachers in PCB-containing schools and referent populations.</p> <p>Methods</p> <p>Blood samples from 18 teachers in PCB-containing schools were analyzed for 57 PCB congeners. Serum PCB concentrations and congener patterns were compared between the teachers, to the 2003-4 NHANES (National Health and Nutrition Examination Survey) data, and to data from 358 Greater Boston area men.</p> <p>Results</p> <p>Teachers at one school had higher levels of lighter (PCB 6-74) congeners compared to teachers from other schools. PCB congener 47 contributed substantially to these elevated levels. Older teachers (ages 50-64) from all schools had higher total (sum of 33 congeners) serum PCB concentrations than age-comparable NHANES reference values. Comparing the teachers to the referent population of men from the Greater Boston area (all under age 51), no difference in total serum PCB levels was observed between the referents and teachers up to 50 years age. However, the teachers had significantly elevated serum concentrations of lighter congeners (PCB 6-74). This difference was confirmed by comparing the congener-specific ratios between groups, and principal component analysis showed that the relative contribution of lighter congeners differed between the teachers and the referents.</p> <p>Conclusions</p> <p>These findings suggest that the teachers in the PCB-containing buildings had higher serum levels of lighter PCB congeners (PCB 6-74) than the referent populations. Examination of the patterns, as well as concentrations of individual PCB congeners in serum is essential to investigating the contributions from potential environmental sources of PCB exposure.</p

An Integrated Assessment and Management Optimization System for Grazinglands

Rangelands and pasturelands are often assessed using different methodologies. The Interpreting Indicators of Rangeland Health and Pasture Condition Scoring methodologies, two techniques used widely across the USA, were developed for rangelands and pasturelands respectively. These two grazingland assessment techniques were determined to be complementary and if integrated could provide an optimized approach to measure grazinglands without regards to specific use (i.e. range or pasture). We present an improved grazingland assessment protocol that merges indicators and attributes from Interpreting Indicators of Rangeland Health and Pasture Condition Scoring methodologies. This Integrated Grazingland Assessment (IGA) approach allows evaluators to assess site conditions and to make interpretations regarding management based on site-specific attributes (soil and site stability, hydrologic function, biotic integrity) that can potentially optimize the ecological potential and livestock carrying capacity of a site. The IGA provides a way of detecting changes in these ecological attributes relative to a site\u27s ecological potential. The IGA can also inform land managers about the utility of an area for livestock production or factors that could be keeping the area from operating at its full productive potential, while accounting for the different management objectives (e.g. increase productivity while maintaining native rangeland, optimizing seed mixes to improve planted pasture productivity) for the grazinglands where these methods are usually applied

The classical dynamics of two-electron atoms near the triple collision

The classical dynamics of two electrons in the Coulomb potential of an attractive nucleus is chaotic in large parts of the high-dimensional phase space. Quantum spectra of two-electron atoms, however, exhibit structures which clearly hint at the existence of approximate symmetries in this system. In a recent paper,(Phys. Rev. Lett. 93, 054302 (2004)), we presented a study of the dynamics near the triple collision as a first step towards uncovering the hidden regularity in the classical dynamics of two electron atoms. The non-regularisable triple collision singularity is a main source of chaos in three body Coulomb problems. Here, we will give a more detailed account of our findings based on a study of the global structure of the stable and unstable manifolds of the triple collision.Comment: 21 pages, 17 figure

Intermanifold similarities in partial photoionization cross sections of helium

Using the eigenchannel R-matrix method we calculate partial photoionization cross sections from the ground state of the helium atom for incident photon energies up to the N=9 manifold. The wide energy range covered by our calculations permits a thorough investigation of general patterns in the cross sections which were first discussed by Menzel and co-workers [Phys. Rev. A {\bf 54}, 2080 (1996)]. The existence of these patterns can easily be understood in terms of propensity rules for autoionization. As the photon energy is increased the regular patterns are locally interrupted by perturber states until they fade out indicating the progressive break-down of the propensity rules and the underlying approximate quantum numbers. We demonstrate that the destructive influence of isolated perturbers can be compensated with an energy-dependent quantum defect.Comment: 10 pages, 10 figures, replacement with some typos correcte