Atom-Chip Fountain Gravimeter.

We demonstrate a quantum gravimeter by combining the advantages of an atom chip for the generation, delta-kick collimation, and coherent manipulation of freely falling Bose-Einstein condensates (BECs) with an innovative launch mechanism based on Bloch oscillations and double Bragg diffraction. Our high-contrast BEC interferometer realizes tens of milliseconds of free fall in a volume as little as a one centimeter cube and paves the way for measurements with sub-µGal accuracies in miniaturized, robust devices.

Double Bragg Interferometry.

We employ light-induced double Bragg diffraction of delta-kick collimated Bose-Einstein condensates to create three symmetric Mach-Zehnder interferometers. They rely on (i) first-order, (ii) two successive first-order, and (iii) second-order processes which demonstrate the scalability of the corresponding momentum transfer. With respect to devices based on conventional Bragg scattering, these symmetric interferometers double the scale factor and feature a better suppression of noise and systematic uncertainties intrinsic to the diffraction process. Moreover, we utilize these interferometers as tiltmeters for monitoring their inclination with respect to gravity.

Interferometry with Bose-Einstein condensates in microgravity.

Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation of the wave nature of matter. Because of their unique coherence properties, Bose-Einstein condensates are ideal sources for an atom interferometer in extended free fall. In this Letter we report on the realization of an asymmetric Mach-Zehnder interferometer operated with a Bose-Einstein condensate in microgravity. The resulting interference pattern is similar to the one in the far field of a double slit and shows a linear scaling with the time the wave packets expand. We employ delta-kick cooling in order to enhance the signal and extend our atom interferometer. Our experiments demonstrate the high potential of interferometers operated with quantum gases for probing the fundamental concepts of quantum mechanics and general relativity.

Bose-Einstein condensation in microgravity.

Albert Einstein's insight that it is impossible to distinguish a local experiment in a "freely falling elevator" from one in free space led to the development of the theory of general relativity. The wave nature of matter manifests itself in a striking way in Bose-Einstein condensates, where millions of atoms lose their identity and can be described by a single macroscopic wave function. We combine these two topics and report the preparation and observation of a Bose-Einstein condensate during free fall in a 146-meter-tall evacuated drop tower. During the expansion over 1 second, the atoms form a giant coherent matter wave that is delocalized on a millimeter scale, which represents a promising source for matter-wave interferometry to test the universality of free fall with quantum matter.

The 2008 ICOH Workshop on Skin Notation.

BACKGROUND: On 29 March 2008 the International Commission on Occupational Health (ICOH) Scientific Committee on Occupational and Environmental Dermatoses organized a Skin Notation Workshop hosted by the 11th International Percutaneous Penetration Perspectives Conference (La Grande Motte, France). Skin notation (S) was chosen as a topic for discussion because this is the only example of existing regulation in the field of dermal risk assessment. The issue was discussed in a previous workshop held in Siena, Italy in 2006 with the objective of focussing on the problems related to S, the different assignment criteria and the attempts to improve the S system made by various international and governmental agencies. A position paper was subsequently published. OBJECTIVES: The workshop in France was a continuation of this activity with the aim of evaluating how the different strategies can improve S. METHODS AND DISCUSSION: The Workshop was divided into two sessions. The first was dedicated to lectures focused on different aspects of S. In the second session participants discussed key issues with the aim of exploring the actions needed to improve international S. systems.

An electronic body-tracking dog?

The use of tracker dogs is the main method of finding hidden bodies, and in their search the dogs use typical scent patterns. "Electronic noses" can also be used to find and compare such patterns. Highly sensitive scent detectors have been successfully applied, e.g. in the examination of foodstuffs, in environmental tests and in material research. This study examined whether electronic sensors can be used to find bodies under outdoor conditions. The carcasses of two coneys were buried in soil at different depths. Over a period of 4 weeks, regular measurements were taken from the buried carcasses and from the control material. In addition, a "fingerprint" of the scent patterns was taken, and gas chromatography-mass spectrometry analyses were performed. Our findings indicate that it may be possible and viable to construct an "electronic body-tracking dog".

Information dissemination and use: critical components in occupational safety and health.

BACKGROUND: Information dissemination is a mandated, but understudied, requirement of occupational and environmental health laws and voluntary initiatives. Research is needed on the factors that enhance and limit the development, transfer, and use of occupational safety and health information (OSH). Contemporary changes in the workforce, workplaces, and the nature of work will require new emphasis on the dissemination of information to foster prevention. METHODS: Legislative and regulatory requirements and voluntary initiatives for dissemination of OSH information were identified and assessed. Literature on information dissemination was reviewed to identify important issues and useful approaches. RESULTS: More than 20 sections of laws and regulations were identified that mandated dissemination of occupational and environmental safety and health information. A four-stage approach for tracking dissemination and considering the flow of information was delineated. Special areas of dissemination were identified: the information needs of the changing workforce, new and young workers; small businesses; and workers with difficulty in understanding or reading English. CONCLUSIONS: We offer a framework for dissemination of OSH information and underscore the need to focus on the extent to which decision-makers and others receive and use such information. More solid data are also needed on current investments in disseminating, diffusing and applying OSH information and on the utility of that information. Am. J. Ind. Med. 44:515-531, 2003. Published 2003 Wiley-Liss, Inc.

Prioritization of NTP reproductive toxicants for field studies.

Population studies that evaluate human reproductive impairment are time consuming, expensive, logistically difficult, and with limited resources must be prioritized to effectively prevent the adverse health effects in humans. Interactions among health scientists, unions, and industry can serve to identify populations exposed to potential hazards and develop strategies to evaluate and apply appropriate controls. This report describes a systematic method for prioritizing chemicals that may need human reproductive health field studies. Rodent reproductive toxicants identified from the National Toxicology Program (NTP) Reproductive Assessment by Continuous Breeding (RACB) protocol were prioritized on the basis of potency of toxic effect and population at risk. This model for prioritization links NTP findings with data from the National Occupational Exposure Survey (NOES) and the Hazardous Substance Data Base (HSDB) or the High Production Volume Chemical Database (HPVC) to prioritize chemicals for their potential impact on worker populations. The chemicals with the highest priority for field study were: dibutyl phthalate, boric acid, tricresyl phosphate, and N, N-dimethylformamide.

Axenic cultivation of anoxygenic phototrophic bacteria, cyanobacteria, and microalgae in a new closed tubular glass photobioreactor.

A low-cost closed tubular glass photobioreactor allowing axenic cultivation of phototrophic microorganisms was constructed. Standard glass tubes were arranged in a helical array providing a working volume of 80 1. The glass tubes were connected with a degassing chamber, which also provided ports for measuring and regulating oxygen supply, pH, foam, and optical density and for adding substrates and antifoam agents as well as disposing of vent gas. A pump module allowed agitation of the medium in the bioreactor at a laminar flow rate of 1.5 m/s. Upstream of the pump module a gas inlet was located, allowing efficient mixing of the used gases with the medium. The temperature of the medium was controlled by a Pt-100 sensor and by a heat exchanger with an effective surface of 0.12 m2 connected to an external thermostat. Irradiation was provided by three light panels each consisting of ten fluorescent tubes. The entire photobioreactor - apart from the light panels and motor - could be sterilized at 121 degrees C in an autoclave. In addition to a detailed description of this photobioreactor, we report on first experiments to cultivate the anoxygenic phototrophic bacteria Rhodobacter sphaeroides and Rhodospirillum rubrum, the oxygenic phototrophic cyanobacterium Synechocystis sp. strain PCC6803, and the microalga Chlorella sp. in this photobioreactor.

Chemicals in the workplace: incorporating human neurobehavioral testing into the regulatory process.

In February 1996, the United Kingdom Health and Safety Executive sponsored a workshop on the role of human neurobehavioral tests in the regulation of chemical exposures in the workplace. This paper presents the review of neurobehavioral testing that was initially prepared for the workshop but has been expanded and updated for publication. Information sources for the review were drawn from "preamble to the regulation," in the 1989 air contaminants project, an attempt by the Occupational Safety and Health Administration to update the 1968 regulatory limits of workplace exposures. The scientific citations listed in the preamble provide a chemical database to review for evidence of neurobehavioral testing to support limit setting. Several conclusions emerged: 1) A wide range of nervous system effects were reported in the scientific citations for the 172 chemicals identified with effects on the nervous system; 2) Citations of studies with human neurobehavioral test results are used to support limit setting, but many are old studies primarily of acute effects; 3) There is frequently a delay of several years after publication before studies with neurobehavioral testing are cited in regulatory forums; 4) With the 1989 proposed regulatory limits never legally adopted, there has not been an update for most of the substances affecting the nervous system since 1971; 5) Investigators should be more aware of the regulatory process and submit studies reporting neurobehavioral test results to organizations that regulate and recommend workplace exposure limits; 6) Issuances in the Federal Register by the U.S. Environmental Protection Agency provide a framework for assessing neurotoxic risks that can be used by investigators to help identify and report nervous system effects using neurobehavioral testing in a more uniform fashion.

Occupational safety and health standards.

If we are to approach developing a safe and healthful workplace in a more timely fashion, a more generic approach must be considered and applied instead of developing recommendations and standards simply on a substance-by-substance basis, an approach that has been the most prominent. Some examples in which developing generic standards may be appropriate are: cholinesterase-inhibiting substances, neurotoxic agents, reproductive hazards, cold environments, and vibration syndrome, to name but a few. It is important to recognize that developing standards based on individual substances often does not allow for the role of synergism, a reaction that has had little study, but it is important in controlling occupational disease and injury. These concerns can be addressed in several ways. One is to look at processes or conditions found in the workplace; for example, coke oven emissions that OSHA has promulgated into a standard and, as NIOSH has done in their recommendations to OSHA for foundries, coal tar products, the manufacture of paint and allied coatings, field sanitation, hazardous waste management, hot environments, and confined spaces. Another is to address groups of similar substances such as NIOSH has done with alkanes, benzidine-based dyes, diisocyanates, dinitrotoluenes, and glycol ethers. A third comprehensive approach is to look at general categories of hazards, such as the generic carcinogen policy, and the hazard communication rule. Finally, risk must be considered in the development of any standard. Nelson Rockefeller once said in relation to an incidence involving a radiation hazard that, "you can't have a riskless society." I would amend this to say that you cannot have a reckless society either. Safety and health regulations are essential and must be designed, promulgated, and then enforced so that a reckless society is avoided or controlled, with a riskless society being the ultimate aim.

Lithium niobate guided-wave network for a coherent receiver.

We report on a packaged LiNbO(3) guided-wave network for a heterodyne receiver that combines a tunable 3-dB coupler with temperature- and wavelength-insensitive optical compensators for continuous reset-free polarization transformation. A fabrication yield of 90% could be achieved by employing indium-tin-oxide-metal electrodes. Characteristic data of the device are given.

Swept wavelength reflectometer for integrated-opticmeasurements.

The experimental investigation of a high-resolution optical reflectometry technique based on the thermally induced sweep of sample refractive index is described. Reflections from surface scratches and the end surfaces of a Ti:LiNbO(3) waveguide were detected with a resolution of <0.2 mm, which is sufficient for the characterization of reflections in integrated-optic devices. Improvement in the dynamic range of the measurement is required for the detection of well-fabricated waveguide features such as bends and Y junctions. Several possibilities exist for making this improvement.