Development of integrated, zero-G pneumatic transporter/rotating paddle incinerator/catalytic afterburner subsystem for processing human wastes on board spacecraft

A four component system was developed which consists of a particle size reduction mechanism, a pneumatic waste transport system, a rotating-paddle incinerator, and a catalytic afterburner to be integrated into a six-man, zero-g subsystem for processing human wastes on board spacecraft. The study included the development of different concepts or functions, the establishment of operational specifications, and a critical evaluation for each of the four components. A series of laboratory tests was run, and a baseline subsystem design was established. An operational specification was also written in preparation for detailed design and testing of this baseline subsystem

Development of an integrated, zero-G pneumatic transporter/rotating-paddle incinerator/catalytic afterburner subsystem for processing human waste on board spacecraft

A baseline laboratory prototype of an integrated, six man, zero-g subsystem for processing human wastes onboard spacecraft was investigated, and included the development of an operational specification for the baseline subsystem, followed by design and fabrication. The program was concluded by performing a series of six tests over a period of two weeks to evaluate the performance of the subsystem. The results of the tests were satisfactory, however, several changes in the design of the subsystem are required before completely satisfactory performance can be achieved

On Unitary Time Evolution in Gowdy T3T^3 Cosmologies

A non-perturbative canonical quantization of Gowdy $T^3$ polarized models carried out recently is considered. This approach profits from the equivalence between the symmetry reduced model and 2+1 gravity coupled to a massless real scalar field. The system is partially gauge fixed and a choice of internal time is performed, for which the true degrees of freedom of the model reduce to a massless free scalar field propagating on a 2-dimensional expanding torus. It is shown that the symplectic transformation that determines the classical dynamics cannot be unitarily implemented on the corresponding Hilbert space of quantum states. The implications of this result for both quantization of fields on curved manifolds and physically relevant questions regarding the initial singularity are discussed.Comment: 16 pages, no figures, latex file; references added, a proof included. Final version to appear in IJMP

Vacuum distillation/vapor filtration water recovery

The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine

Cellular-Resolution Population Imaging Reveals Robust Sparse Coding in the Drosophila Mushroom Body

Sensory stimuli are represented in the brain by the activity of populations of neurons. In most biological systems, studying population coding is challenging since only a tiny proportion of cells can be recorded simultaneously. Here we used two-photon imaging to record neural activity in the relatively simple Drosophila mushroom body (MB), an area involved in olfactory learning and memory. Using the highly sensitive calcium indicator GCaMP3, we simultaneously monitored the activity of >100 MB neurons in vivo (similar to 5% of the total population). The MB is thought to encode odors in sparse patterns of activity, but the code has yet to be explored either on a population level or with a wide variety of stimuli. We therefore imaged responses to odors chosen to evaluate the robustness of sparse representations. Different odors activated distinct patterns of MB neurons; however, we found no evidence for spatial organization of neurons by either response probability or odor tuning within the cell body layer. The degree of sparseness was consistent across a wide range of stimuli, from monomolecular odors to artificial blends and even complex natural smells. Sparseness was mainly invariant across concentrations, largely because of the influence of recent odor experience. Finally, in contrast to sensory processing in other systems, no response features distinguished natural stimuli from monomolecular odors. Our results indicate that the fundamental feature of odor processing in the MB is to create sparse stimulus representations in a format that facilitates arbitrary associations between odor and punishment or reward

Index of pretreatment intensity predicts outcome of high-dose chemotherapy and autologous progenitor cell transplantation in chemosensitive relapse of Hodgkin's disease

Purpose To identify prognostic factors in patients with chemosensitive relapsed Hodgkin's disease treated by high-dose chemotherapy with autologous progenitor cell transplantation (HDC) and to compare the duration of treatment-free remission prior to HDC with the progression-free survival after HDC in individual patients. Patients and methods Forty-five consecutive patients were analyzed retrospectively. We devised an index of pretreatment intensity (IPTI) based number of different chemo- and radio-therapy regimens given between diagnosis and HDC and on the duration of disease. Results With a median follow-up of 47 months the post-transplant event-free survival (EFS) was 44% and the overall survival. (OAS) was 62% at four years. The IPTI allowed to discriminate between a low and a high-risk group with a four-year post-transplant EFS of 66% and 11% and a OAS of 87% and 28%, respectively (P = 0.0001). Of the 39 patients with sufficient follow-up after HDC, post-transplant EFS lasted on average ≥ 18.5 months longer than the pretransplant treatment-free remission. Conclusions HDC with the CBV regimen confers significant benefit to patients with chemosensitive relapsed Hodgkin's disease. The IPTI may help to select patients with a good response to HDC and to identify poor prognosis patients suitable for experimental protocols or palliative care onl

A high-precision polarimeter

We have built a polarimeter in order to measure the electron beam polarization in hall C at JLAB. Using a superconducting solenoid to drive the pure-iron target foil into saturation, and a symmetrical setup to detect the Moller electrons in coincidence, we achieve an accuracy of <1%. This sets a new standard for Moller polarimeters.Comment: 17 pages, 9 figures, submitted to N.I.