New approaches to the measurement of chlorophyll, related pigments and productivity in the sea

In the 1984 SBIR Call for Proposals, NASA solicited new methods to measure primary production and chlorophyll in the ocean. Biospherical Instruments Inc. responded to this call with a proposal first to study a variety of approaches to this problem. A second phase of research was then funded to pursue instrumentation to measure the sunlight stimulated naturally occurring fluorescence of chlorophyll in marine phytoplankton. The monitoring of global productivity, global fisheries resources, application of above surface-to-underwater optical communications systems, submarine detection applications, correlation, and calibration of remote sensing systems are but some of the reasons for developing inexpensive sensors to measure chlorophyll and productivity. Normally, productivity measurements are manpower and cost intensive and, with the exception of a very few expensive multiship research experiments, provide no contemporaneous data. We feel that the patented, simple sensors that we have designed will provide a cost effective method for large scale, synoptic, optical measurements in the ocean. This document is the final project report for a NASA sponsored SBIR Phase 2 effort to develop new methods for the measurements of primary production in the ocean. This project has been successfully completed, a U.S. patent was issued covering the methodology and sensors, and the first production run of instrumentation developed under this contract has sold out and been delivered

Modeling Signal Transduction in Classical Conditioning with Network Motifs

Biological networks are constructed of repeated simplified patterns, or modules, called network motifs. Network motifs can be found in a variety of organisms including bacteria, plants, and animals, as well as intracellular transcription networks for gene expression and signal transduction processes in neuronal circuits. Standard models of signal transduction events for synaptic plasticity and learning often fail to capture the complexity and cooperativity of the molecular interactions underlying these processes. Here, we apply network motifs to a model for signal transduction during an in vitro form of eyeblink classical conditioning that reveals an underlying organization of these molecular pathways. Experimental evidence suggests there are two stages of synaptic AMPA receptor (AMPAR) trafficking during conditioning. Synaptic incorporation of GluR1-containing AMPARs occurs early to activate silent synapses conveying the auditory conditioned stimulus and this initial step is followed by delivery of GluR4 subunits that supports acquisition of learned conditioned responses (CRs). Overall, the network design of the two stages of synaptic AMPAR delivery during conditioning describes a coherent feed-forward loop (C1-FFL) with AND logic. The combined inputs of GluR1 synaptic delivery AND the sustained activation of 3-phosphoinositide-dependent protein-kinase-1 (PDK-1) results in synaptic incorporation of GluR4-containing AMPARs and the gradual acquisition of CRs. The network architecture described here for conditioning is postulated to act generally as a sign-sensitive delay element that is consistent with the non-linearity of the conditioning process. Interestingly, this FFL structure also performs coincidence detection. A motif-based approach to modeling signal transduction can be used as a new tool for understanding molecular mechanisms underlying synaptic plasticity and learning and for comparing findings across forms of learning and model systems

The Effects of Seated Position on Occupant Kinematics in Low-speed Rear-end Impacts

Copyright © 2005 SAE International Seventeen rear-end impacts with a nominal 8 km/hr change in velocity to five human subjects in four positions were conducted. The four seated positions consisted of the Normal position, with the torso against the seat back, looking straight ahead, hands on the steering wheel, and feet on the floor; the Torso Lean position, with the torso leaned forward approximately 10 degrees away from the seat back; the Head Flex position, with the head flexed forward approximately 20 degrees from normal; and the Head Flex / Torso Lean position, with the head flexed forward approximately 20 degrees from normal and the torso leaned forward approximately 10 degrees from normal position. Relative to the Normal position, it was found that in both positions involving the torso lean, the peak head acceleration for the subject’s head was reduced during the head-restraint impact. Further, the inertial acceleration of the head due to the forces on the neck, prior to the head rest impact, was somewhat higher for the two positions involving torso lean. Minor, transient, whiplash associated disorder (WAD) symptoms were noted. The nominal change in velocity used in this study appears to be of a reasonable magnitude to continue human subject out of position (OOP) testing

How firms collaborate to compete internationally : An ethnographic understanding.

This thesis seeks to develop insights into the nature of inter-organisational collaborations in small and medium sized enterprises (SMEs) as a means to expand into foreign markets and improve their international competitiveness. Its interest is in internationalisation as a growth and development process as experienced by these SMEs and in the ways in which they developed inter-organisational relationships as a way to overcome the challenges of competing internationally. The central proposition of this thesis is that it is through the dynamic processes of forming inter-organisational relationships and acquiring new knowledge through inter-organisational learning that SMEs build the capability to create a sustainable 'step change' in the internationalisation process. This thesis follows a naturalistic paradigm with the aim to provide meaningful insights and acknowledge the possibility of multiple answers to SME internationalisation problems. It is an ethnographic account of the managerial behaviours of the participating firms.Analysis of the findings reveals an emergent process that is dependent upon the comparative achievements in negotiation, commitment and execution. The focus of this process incorporates the formal, legal, and informal socio-psychological dimensions by which organisational partners jointly negotiate, commit to, and execute their relationship in ways that achieve efficient and equitable outcomes and internal solutions to conflicts when they arise. Inter-organisational learning which is acquired through inter-organisational relationships can serve as an enabling mechanism for internationalisation for SMEs. Collaborative relationships can produce a win-win learning payoff through inter-organisational learning for the participating partners. Valuable learning opportunities can emerge when different firms with differentiated, unique skills and knowledge bases are brought together. If properly managed, inter-organisational learning can produce tangible learning and performance improvements for all partners

Blood acetylcholinesterase and butyrylcholinesterase as biomarkers of cholinesterase depression among pesticide handlers

Agricultural pesticide handlers are at an elevated risk for overexposure to organophosphate (OP) pesticides, but symptoms can be difficult to recognize, making biomarkers invaluable for diagnosis. Occupational monitoring programs for cholinesterase depression generally rely on measuring activity of either of two common blood cholinesterases which serve as proxy measurements for nervous-system acetylcholinesterase activity: red blood cell acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BChE). These biomarkers, however, may be affected differentially by some OPs and the relationship between them has not been well characterized. We aim to determine the association between blood acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity levels and assess whether they produce comparable classifications of clinical cholinesterase depression among organophosphate pesticide handlers

Symmetry Breaking in the Schr\"odinger Representation for Chern-Simons Theories

This paper discusses the phenomenon of spontaneous symmetry breaking in the Schr\"odinger representation formulation of quantum field theory. The analysis is presented for three-dimensional space-time abelian gauge theories with either Maxwell, Maxwell-Chern-Simons, or pure Chern-Simons terms as the gauge field contribution to the action, each of which leads to a different form of mass generation for the gauge fields.Comment: 16pp, LaTeX , UCONN-94-

Urinary biomarker concentrations of captan, chlormequat, chlorpyrifos and cypermethrin in UK adults and children living near agricultural land

There is limited information on the exposure to pesticides experienced by UK residents living near agricultural land. This study aimed to investigate their pesticide exposure in relation to spray events. Farmers treating crops with captan, chlormequat, chlorpyrifos or cypermethrin provided spray event information. Adults and children residing ≤100 m from sprayed fields provided first-morning void urine samples during and outwith the spray season. Selected samples (1–2 days after a spray event and at other times (background samples)) were analysed and creatinine adjusted. Generalised Linear Mixed Models were used to investigate if urinary biomarkers of these pesticides were elevated after spray events. The final data set for statistical analysis contained 1518 urine samples from 140 participants, consisting of 523 spray event and 995 background samples which were analysed for pesticide urinary biomarkers. For captan and cypermethrin, the proportion of values below the limit of detection was greater than 80%, with no difference between spray event and background samples. For chlormequat and chlorpyrifos, the geometric mean urinary biomarker concentrations following spray events were 15.4 μg/g creatinine and 2.5 μg/g creatinine, respectively, compared with 16.5 μg/g creatinine and 3.0 μg/g creatinine for background samples within the spraying season. Outwith the spraying season, concentrations for chlorpyrifos were the same as those within spraying season backgrounds, but for chlormequat, lower concentrations were observed outwith the spraying season (12.3 μg/g creatinine). Overall, we observed no evidence indicative of additional urinary pesticide biomarker excretion as a result of spray events, suggesting that sources other than local spraying are responsible for the relatively low urinary pesticide biomarkers detected in the study population

Neurologic Symptoms in Licensed Private Pesticide Applicators in the Agricultural Health Study

Exposure to high levels of many pesticides has both acute and long-term neurologic consequences, but little is known about the neurotoxicity of chronic exposure to moderate levels of pesticides. We analyzed cross-sectional data from 18,782 white male licensed private pesticide applicators enrolled in the Agricultural Health Study in 1993–1997. Applicators provided information on lifetime pesticide use and 23 neurologic symptoms typically associated with pesticide intoxication. An indicator of more symptoms (≥10 vs. < 10) during the year before enrollment was associated with cumulative lifetime days of insecticide use: odds ratios (95% confidence intervals) were 1.64 (1.36–1.97) for 1–50 days, 1.89 (1.58–2.25) for 51–500 days, and 2.50 (2.00–3.13) for > 500 days, compared with never users. A modest association for fumigants [> 50 days, 1.50 (1.24–1.81)] and weaker relationships for herbicides [> 500 days, 1.32 (0.99–1.75)] and fungicides [> 50 days, 1.23 (1.00–1.50)] were observed. Pesticide use within the year before enrollment was not associated with symptom count. Only associations with insecticides and fumigants persisted when all four pesticide groups were examined simultaneously. Among chemical classes of insecticides, associations were strongest for organophosphates and organochlorines. Associations with cumulative exposure persisted after excluding individuals who had a history of pesticide poisoning or had experienced an event involving high personal pesticide exposure. These results suggest that self-reported neurologic symptoms are associated with cumulative exposure to moderate levels of fumigants and organophosphate and organochlorine insecticides, regardless of recent exposure or history of poisoning