Detecting photosynthetic algal pigments in natural populations using a high-spectral-resolution spectroradiometer

Reflectance data from a high spectral resolution spectroradiometer were obtained onboard a ship in Plymouth coastal waters. These data were analysed to detect algal photosynthetic accessory pigments for comparison with absorption spectra as measured in the laboratory by a spectrophotometer. The overall spectral characteristics of Plymouth waters allowed identification as to population composition. Derivative analysis of the spectra was used to resolve characteristic peaks of specific pigments. It was determined that chlorophyll pigments, a specific carotenoid and sea water absorption bands were detectable in the reflectance data. Absorption bands of photosynthetic and accessory pigments were assessed through chromatographic pigment analysis.     

Influence of operator orientation on relative organizational mapping and spatial compatibility.

Following up on a study by Worringham and Beringer (1989) that examined the influence of operator orientation on visual-motor performance, Experiment 1 employed a choice reaction time paradigm in which participants had to make rapid, discrete movements with a lever in response to a discrete stimulus. In Experiment 2, participants had to synchronize rhythmic movements with an oscillating visual display. Operator orientation with respect to stimulus display and response array locations was varied to examine the influence of global spatial relations. Display orientation was varied to examine the influence of spatial configuration. Mapping rules were varied to examine the effects of spatial mapping. In Experiment 1, the spatial mapping that yielded faster responses was dependent upon the stimulus display-response array configuration and the global relation. Under a parallel configuration, participants appeared to code the spatial aspects of the stimulus display and response in a manner that was unaffected by the global spatial relation. Under an orthogonal configuration, spatial mapping effects were dependent upon the global relation. In Experiment 2, the global spatial relation did not have an impact on the uniformity of co-ordination under different configuration or mapping conditions. Spatial configuration influenced whether or not differences between spatial mapping rules emerged. Together, the results speak to the relative nature of stimulus-response coding that underlie compatibility phenomena. In addition, the results have potential importance for the design of human-machine systems that allow flexibility in operator orientation.     

Silicon–Carbon Stressors With High Substitutional Carbon Concentration and In Situ Doping Formed in Source/Drain Extensions of n-Channel Transistors

We report the first demonstration of n-channel field-effect transistors (N-FETs) with in situ phosphorus-doped silicon-carbon (SiCP) stressors incorporated in the source/drain extension (SDE) regions. A novel process which formed recessed SDE regions followed by selective epitaxy of SiCP was adopted. High in situ doping contributes to low series resistance to channel resistance ratio and is important for reaping the benefits of strain. Substitutional carbon concentration was varied, showing enhanced drive current with increased for comparable off-state leakage, series resistance, and control of short-channel effects. A record high carbon substitutional concentration of 2.1% was achieved. Use of heavily doped silicon-carbon stressor with large lattice mismatch with respect to Si and placed in close proximity to the channel region in the SDE regions is expected to be important for strain engineering in nanoscale N-FETs.     

A Method of Constrained Randomization for 2 n Factorials

In an experiment in which treatments are applied and observed in a sequential manner, if not all treatment combinations may be placed (run) in adjacent positions then the usual technique of full randomization cannot be carried out. In such instances some technique of randomization, constrained by the requirements of adjacency on the various treatment combinations, is desired in order that the properties of the statistical analysis may be determined. This paper presents methods of constrained randomization for 2 ^n—p factorial experiments in blocked designs when the requirment (imposed by the nature of the process under investigation) on adjacent treatment combinations restricts the number of factor levels which may be changed from run to run (treatment combination to adjacent treatment combination). The method of constrained randomization provides a basis for a statistical analysis utilizing the randomization model, which results in unbiased estimates of treatment effects and an unbiased estimate of experimental error.     

Sample Size Determination for Tolerance Limits

The problem of determining sample size to take for a tolerance limit L(X), where L(X) is a function of a random sample X ₁, …, X_n from a distribution with density f(x : θ), and

is investigated. A criteriorl of “goodness” of tolerance limits is developed and a method given, using this criterion, for solving the sample size problem. Examples are given using the uniform, exponential, and normal distributions as underlying models.     

Protein and energy intakes affected amino acid concentrations in plasma, muscle, and liver, and cell signaling in the liver of growing dairy calves

The nutrient content of and feeding recommendations for milk replacers (MR) vary widely in North America, and acceleration of growth through manipulation of protein and energy intakes can reduce rearing costs of dairy operations. The effects of varying the protein and energy intake of MR on metabolite concentrations in plasma, liver, and muscle and the phosphorylation activity of protein kinase B (AKT) and ribosomal protein S6 (rpS6) cell signals in liver and muscle were assessed. Twenty-four newborn Holstein calves were fed 1 of 4 MR for 9 wk (n=6/treatment): (1) a 20% crude protein (CP), 20% fat MR fed at 441 g of dry matter (DM)/d (CON); (2) a high-protein, medium-fat MR (HPMF; 28% CP, 20% fat) fed at 951 g of DM/d; (3) a high-protein, high-fat MR (HPHF; 27% CP, 28% fat) fed at 951 g of DM/d; and (4) HPHF fed at 1,431 g of DM/d (HPHF+). Water and starter (20% CP, 1.43% fat) were offered ad libitum and calves were fed MR twice daily. Plasma samples were obtained at 1, 5, and 9 wk of age. Calves were not weaned and were slaughtered after the last blood sampling. Liver and muscle tissues were collected and analyzed for metabolite concentrations and cell signaling activity. Calves fed all treatments had lower plasma concentrations of Phe and Tyr, and a trend for lower Leu, but greater concentrations of Thr relative to calves fed CON. Calves fed all treatments had increased muscle concentrations of Met and muscle to plasma ratios of Phe, Tyr, and branched-chain amino acids compared with CON. All treatments increased liver to plasma ratios of Phe and Tyr but diminished the ratios of Met compared with CON. Phosphorylation of protein kinase B was not affected by treatment; however, relative to calves fed HPHF, HPMF and HPHF+ diets increased phosphorylation ratios of ribosomal protein S6 in the liver. Therefore, the changes in plasma and tissue concentrations and plasma to tissue ratios of amino acids were associated with enhanced growth rates. However, cell signaling activity was not consistent with accelerated growth in calves fed treatments with increased contents of energy and protein possibly due to confounding effects of diet (MR + starter) or fasting before tissue harvesting. Muscle concentrations of Met might have a regulatory role in protein synthesis in rapidly growing calves fed high levels of CP and energy.     

Role of electron microscopy and other special techniques in the diagnosis of childhood round cell tumors

A series of case presentations show unique challenges associated with childhood round cell tumors and the role of ancillary techniques in diagnosis. Electron microscopy is shown to be the most powerful individual technique. Immunohistochemistry is less effective but also essential. Other ancillary techniques may provide needed additional diagnostic information. Because this is an area where it is of great importance to secure the most rapid, accurate, and specific diagnosis possible, an integrated multimodal approach is recommended--incorporating light microscopic, electron microscopic, and immunohistochemical studies as a matter of routine, and providing for cytogenetic and/or molecular diagnostic studies as indicated.     

In vivo immune evasion mediated by the herpes simplex virus type 1 immunoglobulin G Fc receptor

Herpes simplex virus (HSV) glycoproteins gE and gI form an immunoglobulin G (IgG) Fc receptor (FcgammaR) that binds the Fc domain of human anti-HSV IgG and inhibits Fc-mediated immune functions in vitro. gE or gI deletion mutant viruses are avirulent, probably because gE and gI are also involved in cell-to-cell spread. In an effort to modify FcgammaR activity without affecting other gE functions, we constructed a mutant virus, NS-gE339, that has four amino acids inserted into gE within the domain homologous to mammalian IgG FcgammaRs. NS-gE339 expresses gE and gI, is FcgammaR-, and does not participate in antibody bipolar bridging since it does not block activities mediated by the Fc domain of anti-HSV IgG. In vivo studies were performed with mice because the HSV-1 FcgammaR does not bind murine IgG; therefore, the absence of an FcgammaR should not affect virulence in mice. NS-gE339 causes disease at the skin inoculation site comparably to wild-type and rescued viruses, indicating that the FcgammaR- mutant virus is pathogenic in animals. Mice were passively immunized with human anti-HSV IgG and then infected with mutant or wild-type virus. We postulated that the HSV-1 FcgammaR should protect wild-type virus from antibody attack. Human anti-HSV IgG greatly reduced viral titers and disease severity in NS-gE339-infected animals while having little effect on wild-type or rescued virus. We conclude that the HSV-1 FcgammaR enables the virus to evade antibody attack in vivo, which likely explains why antibodies are relatively ineffective against HSV infection.     

How to obtain funding for your project

Project development is an exacting and time consuming task. Grant applicants may expend inordinate amounts of time searching the literature on their topic area, consulting with experts in the field and others who have run similar research or projects, eliciting and incorporating the views of major stakeholders and developing a method to answer the research question. While those who are successful in attracting funding experience the elation that accompanies achievement, those whose applications are rejected may experience profound disappointment. The aim of this paper is to maximise the potential for researchers to celebrate their success by suggesting a number of strategies for avoiding the pitfalls of application development. Potential sources of funding are also discussed.     

Rendezvous Guidance Trajectories via Multiple-Subarc Sequential Gradient-Restoration Algorithm

We consider the three-dimensional rendezvous between a target spacecraft in a circular orbit and a chaser spacecraft with an initial separation distance and an initial separation velocity. We assume that the chaser spacecraft has variable mass and that its trajectory is governed by three controls, one determining the thrust magnitude and two determining the thrust direction. We employ the Clohessy–Wiltshire equations, describing the relative motion of the chaser vis-à-vis the target, and the multiple-subarc sequential gradient-restoration algorithm to produce first optimal trajectories and then guidance trajectories for the following problems: P1—minimum time, fuel free; P2—minimum fuel, time free; P3—minimum time, fuel given; P4—minimum fuel, time given; and P5—minimum time×fuel, time and fuel free. Clearly, P1 and P2 are basic problems, while P3, P4, and P5 are compromise problems. Problem P1 leads to a two-subarc solution including a max-thrust subarc followed by another max-thrust subarc. Problem P2 leads to a four-subarc solution including two coasting subarcs alternating with two max-thrust subarcs. Problems P5 leads to a three-subarc solution including two max-thrust subarcs alternating with one coasting subarc. Problems P3 and P4 include P1, P2, and P5 as particular cases and lead to two-, three-, or four-subarcs solutions depending on the prescribed value of fuel or time. For all problems, the thrust magnitude control is saturated at one of its extreme values: in optimization studies, we determine the best thrust direction controls; in guidance studies, we force the thrust direction controls to be constant in each subarc and determine the best thrust direction parameters. Of course, the time lengths of all the subarcs must also be determined. The computational results show that, for Problems P1–P5, the performance index of the multiple-subarc guidance trajectory approximates well the performance index of the multiple-subarc optimal trajectory: the pairwise relative differences in performance index are less than 1/100 in all cases. To sum up, the produced guidance trajectories are highly efficient and yet quite simple in implementation.