Virus Reduction by the Stanford Onsite Wastewater Treatment System

A field study to examine the Stanford Onsite Wastewater Treatment System\u27s ability to remove bacteriophage from wastewater was conducted. MS2 Coliphage was Injected Into the low pressure pipe (LPP) distribution system to achieve an Influent concentration of 1.6 x 106 plague forming units per milliliter (PFU/ml). The bacteriophage was Injected Into the system three times during the day, and samples were taken from drainage tiles of the treatment system. Tile drainage was assayed on conform bacteria host cultures for MS2 phage. The treatment system removed two to three logs (99% to 99.9%) of the phage. During the past two years, the treatment system has also reduced total organic carbon from 55 mg/1 to 5 mg/1. The system also reduced the ammonium-nitrogen concentration from 41 mg/1 to 1 mg/1. The nitrate-nitrogen concentration rose from less than 1 mg/1 1n the Influent to 4 mg/1 1n the effluent. Over the past two years, the geometric mean fecal coliform concentration was 18 colony-forming units per ml (CFU/ml). The effluent water quality meets the Arkansas Department of Health, Standards for Outdoor Bathing Places

Image Processing Instrumentation for Giardia lamblia Detection

Currently, the identification and enumeration of Giardia Iamblia cysts are based upon microscopic methods requiring individuals proficient in this area. It is a tedious process which consumes time that could be constructively used elsewhere. This project attempts to alleviate that burden by employing a computer to automatically process Indirect Fluorescent Antibody (IFA) prepared slides using digital image processing techniques. A computer controlled frame grabber, in conjunction with a CCD TV camera mounted on the epi-fluorescence microscope phototube, captures the light intensities of the objects in view under the microscope objective. The captured image is stored as pixels, with each pixel having a numerical value that can be altered using linear contrast enhancement and bit-slicing to emphasize the cysts and eliminate the majority of unwanted objects from the image. The altered image is then analyzed by a vector trace routine for typical area and perimeters characteristic to Giardia lamblia cysts. Objects in the image matching these characteristics are most likely cysts and are added to a running tally of the number of cysts present on the slide

Assessment of the Effects of Household Chemicals Upon Individual Septic Tank Performances

A laboratory study and a field study were performed to determine the amounts of specific household chemicals required to destroy bacteria populations in individual domestic septic tanks. The particular chemicals evaluated include liquid chlorine bleach, High Test Hypochlorite (HTH), Lysol disinfectant and Drano crystal. The laboratory study was performed to determine the approximate chemical concentrations to destroy the bacteria in the septic tank, and the field study showed the actual effect of the chemicals upon the bacteria in terms of reduction of the number of bacteria in the septic tank as well as the time required for the bacterial population to recover. A liquid bleach concentration of 1.85 ml/l destroyed the bacteria in the septic tanks. This corresponds to 7 liters (1.85 gallons) of liquid bleach in a 3780 liter (1000 gallon) septic tank. After addition of chlorine bleach, and within approximately 30 hours of normal septic system usage, the bacterial population had recovered to its original concentration. A Lysol concentration of 5.0 ml/l destroyed the bacteria in the domestic tanks. This corresponds to 19 liters (5.0 gallons) of Lysol in a 3780 (1000 gallon) septic tank. Following the addition of Lysol, the bacteria population recovered to its original concentration within approximately 60 hours (2.5 days). A Drano concentration of 3.0 mg/l destroys the bacteria in a septic tank. This corresponds to 11.3 grams (0.4 ounces) in a 3780 liter (1000 gallon) septic tank. The bacterial population recovers to its original concentration within 48 hours following the addition of the Drano

Foundations for Cooperating with Control Noise in the Manipulation of Quantum Dynamics

This paper develops the theoretical foundations for the ability of a control field to cooperate with noise in the manipulation of quantum dynamics. The noise enters as run-to-run variations in the control amplitudes, phases and frequencies with the observation being an ensemble average over many runs as is commonly done in the laboratory. Weak field perturbation theory is developed to show that noise in the amplitude and frequency components of the control field can enhance the process of population transfer in a multilevel ladder system. The analytical results in this paper support the point that under suitable conditions an optimal field can cooperate with noise to improve the control outcome.Comment: submitted to Phys. Rev.

Comparison of Pressurized and Gravity Distribution Systems for Wastewater Treatment

Pressurized distribution of domestic wastewater over a sand filter surface achieves better treatment than gravity distribution. The pressurized distribution system caused the filter to better remove organics (BOD₅) and suspended solids. Pressurized distribution also caused the sand filter to achieve more complete nitrification than the filter having gravity distribution. Two slow sand filters 15.2 cm wide, 3.1 m long and 15.2 cm deep were built and loaded with domestic septic tank effluent for 250 days at a rate of 5.1 cm per day. Influent and effluent samples were collected and analyzed for five-day Biochemical Oxygen Demand (BOD₅), suspended solids, ammonia- nitrogen, and nitrate-nitrogen. One filter received septic tank effluent through a 10 cm nominal diameter PVC perforated pipe viaa distribution box dosed by a pump with gravity flow from the distribution box to the pipe. The other filter received water through a 2.5 cm nominal diameter PVC pipe having 0.4 cm diameter holes drilled 76.2 cm on center. The gravity distribution filter system achieved mean effluent values of 36.4 mg// BOD₅ , 19.8 mg// suspended solids, 37.6 mg// ammonia-nitrogen, and 46.6 mg// nitrate-nitrogen. The pressurized distribution system achieved 19.1 mg// BOD₅\u3e 12.2 mg// suspended solids, 25.3 mg// ammonia-nitrogen, and 64.03 mg// nitrate-nitrogen. Influent to the filters averaged 132.1 mg// , 90.3 mg//, 70.3 mg// , and 3.6 mg// BOD₅ , suspended solids, ammonia-nitrogen, and nitrate- nitrogen, respectively

Qudit versions of the qubit "pi-over-eight" gate

When visualised as an operation on the Bloch sphere, the qubit "pi-over-eight" gate corresponds to one-eighth of a complete rotation about the vertical axis. This simple gate often plays an important role in quantum information theory, typically in situations for which Pauli and Clifford gates are insufficient. Most notably, when it supplements the set of Clifford gates then universal quantum computation can be achieved. The "pi-over-eight" gate is the simplest example of an operation from the third level of the Clifford hierarchy (i.e., it maps Pauli operations to Clifford operations under conjugation). Here we derive explicit expressions for all qudit (d-level, where d is prime) versions of this gate and analyze the resulting group structure that is generated by these diagonal gates. This group structure differs depending on whether the dimensionality of the qudit is two, three or greater than three. We then discuss the geometrical relationship of these gates (and associated states) with respect to Clifford gates and stabilizer states. We present evidence that these gates are maximally robust to depolarizing and phase damping noise, in complete analogy with the qubit case. Motivated by this and other similarities we conjecture that these gates could be useful for the task of qudit magic-state distillation and, by extension, fault-tolerant quantum computing. Very recent, independent work by Campbell, Anwar and Browne confirms the correctness of this intuition, and we build upon their work to characterize noise regimes for which noisy implementations of these gates can (or provably cannot) supplement Clifford gates to enable universal quantum computation.Comment: Version 2 changed to reflect improved distillation routines in arXiv:1205.3104v2. Minor typos fixed. 12 Pages,2 Figures,3 Table

Ultra-rapid laser protein micropatterning: screening for directed polarization of single neurons

Protein micropatterning is a powerful tool for studying the effects of extracellular signals on cell development and regeneration. Laser micropatterning of proteins is the most flexible method for patterning many different geometries, protein densities, and concentration gradients. Despite these advantages, laser micropatterning remains prohibitively slow for most applications. Here, we take advantage of the rapid multi-photon induced photobleaching of fluorophores to generate sub-micron resolution patterns of full-length proteins on polymer monolayers, with sub-microsecond exposure times, i.e. one to five orders of magnitude faster than all previous laser micropatterning methods. We screened a range of different PEG monolayer coupling chemistries, chain-lengths and functional caps, and found that long-chain acrylated PEG monolayers are effective at resisting non-specific protein adhesion, while permitting efficient cross-linking of biotin-4-fluorescein to the PEG monolayers upon exposure to femtosecond laser pulses. We find evidence that the dominant photopatterning chemistry switches from a two-photon process to three- and four-photon absorption processes as the laser intensity increases, generating increasingly volatile excited triplet-state fluorophores, leading to faster patterning. Using this technology, we were able to generate over a hundred thousand protein patterns with varying geometries and protein densities to direct the polarization of hippocampal neurons with single-cell precision. We found that certain arrays of patterned triangles as small as neurite growth cones can direct polarization by impeding the elongation of reverse-projecting neurites, while permitting elongation of forward-projecting neurites. The ability to rapidly generate and screen such protein micropatterns can enable discovery of conditions necessary to create in vitro neural networks with single-neuron precision for basic discovery, drug screening, as well as for tissue scaffolding in therapeutics.Hertz Foundation (Fellowship)National Institutes of Health (U.S.) (R01 EUREKA Award 1-R01-NS066352)David & Lucile Packard Foundation (Award in Science and Engineering

Using Viruses to Examine Soil Treatment of Septic Tank Effluent

Viral contamination of drinking water supplies due to inadequate renovation of septic tank effluent (STE) is a public health concern. The purpose of this paper is to illustrate the use of a bacteriophage to evaluate virus movement in a soil treatment system. Viruses - MS2 bacteriophage - were injected into a wastewater treatment system with soil absorption trenches and drainage tiles, and the drain tile effluent was collected and assayed for the phage. The virus suspension was assayed and a measured amount of STE and virus suspension was pumped into the system allowing for calculation of the influent virus titer. Results of the virus assays showed that the wastewater treatment system generally achieves a 99.0 (2 log) to 99.9% (3 log) reduction in the concentration of viable bacteriophage after moving through one meter of silt loam soil. This paper illustrates the procedures to utilize and assay for bacteriophage in the harsh environment of a working onsite wastewater treatment system

Non-commutativity and Supersymmetry

We study the extent to which the gauge symmetry of abelian Yang-Mills can be deformed under two conditions: first, that the deformation depend on a two-form scale. Second, that the deformation preserve supersymmetry. We show that (up to a single parameter) the only allowed deformation is the one determined by the star product. We then consider the supersymmetry algebra satisfied by NCYM expressed in commutative variables. The algebra is peculiar since the supercharges are not gauge-invariant. However, the action, expressed in commutative variables, appears to be quadratic in fermions to all orders in theta.Comment: 21 pages, LaTeX; a reference adde