A printer model using signal processing techniques

An accurate printer model that is efficient enough to be used by halftoning algorithms is proposed. The proposed signal processing model (SPM) utilizes a physical model to train adaptive linear combiners (ALCs), after which the average exposure of each subpixel for any input pattern can be calculated using the optimized weight vector. The SPM can be used to model multi-level halftoning and resolution enhancement, as well as traditional halftoning. The SPM is comprised of a single ALC layer followed by a peak-to-average ratio (PAR) correction layer, which serves to produce a PAR of less than 1.5 in the modeled exposure. The PCN (PAR correction network) employs one ALC/pixel and exploits the physics governing the characteristics of exposure in small regions. A relatively small number of training patterns suffices to train the SPM.     

Efficient random subcloning of DNA sheared in a recirculating point-sink flow system

Based on a high-performance liquid chromatographic pump, we have built a device that allows recirculation of DNA through a 63-microm orifice with ensuing fractionation to a minimum fragment size of approximately 300 base pairs. Residence time of the DNA fragments in the converging flow created by a sudden contraction was found to be sufficiently long to allow extension of the DNA molecules into a highly extended conformation and, hence, breakage to occur at midpoint. In most instances, 30 passages sufficed to obtain a narrow size distribution, with >90% of the fragments lying within a 2-fold size distribution. The shear rate required to achieve breakage was found to be inversely proportional to the 1.0 power of the molecular weight. Compared with a restriction digest, up to 40% of all fragments could be cloned directly, with only marginal improvements in cloning efficiency having been observed upon prior end repair with Klenow, T4 polymerase or T4 polynucleotide kinase. Sequencing revealed a fairly random distribution of the fragments.     

Childhood fibrous dysplasia presenting as blindness: a skull base approach for resection and immediate reconstruction

Fibrous dysplasia is an abnormal fibroosseous process of bone of unknown cause. The incidence of skull involvement varies, painless enlargement being the most common presenting symptom. Change in vision is a rare but recognized finding. We report a 3-year-old boy with extreme fibrous dysplasia involving the skull base, who presented with blindness. He underwent exposure osteotomies of the frontal bones and orbits to provide access for skull base tumor removal. The orbital roofs were reconstructed with microplate-fixed cranial grafts. One and one half years after tumor excision followed by immediate reconstruction, the boy retains facial symmetry, and his ocular function has not deteriorated.     

The band areas of proteins determined by fluorescent scanning in the commercial automated gel electrophoresis apparatus

An automated gel electrophoresis apparatus, recently available commercially, allows one to follow the band during electrophoresis in real time, and lends itself therefore to an evaluation of bandwidth as a function of migration time (the dispersion coefficient), resolution and band shape. These determinations assume the constancy of band area with migration time and at various gel concentrations. The purpose of the present study was to verify these assumptions. Representative proteins and sodium dodecyl sulfate (SDS)-proteins, either natively fluorescent or fluorescein carboxylate labeled, were found to exhibit band areas which approach constancy as a function of migration time in both agarose and polyacrylamide gel electrophoresis, provided that (i) the protein concentration under the band was low enough to obviate self-quenching of fluorescence; (ii) the separation of the protein of interest from contaminants had progressed sufficiently during the time at which band areas were measured; (iii) the baseline under the peak was sufficiently well defined. However, band areas decrease with increasing gel concentration. Protein peaks exhibited leading and trailing tails. The ratio of the combined tail area to total area appeared to be near-constant at varying migration times. However, that ratio increases with increasing gel concentration. The tail area does not appear to be an artifact of fluorometric detection since it is reproduced upon fluorimetric analysis of the protein eluted from gel slices after electrophoresis. However, it may be due to photochemical destruction under the conditions of repetitive fluorometric peak detection.     

Hydrologic regionalisation impacts on wet-weather control selection.

Continuous simulation is performed using the US Environmental Protection Agency (USEPA) Storm Water Management Model (SWMM) to evaluate regional differences around the United States in hydrologic and water quality performance of wet-weather controls. Controls are characterised as being limited by peak inflow rate (i.e. any device with little or no storage, such as screens, filters and some proprietary devices) or by storage capacity (e.g., ponds, tanks). For flow-limited devices, results are presented in the form of percentage of annual runoff volume captured (passing through the device) for a given inflow capacity. For storage-limited devices, results are presented in two forms: percentage of annual runoff volume captured as a function of unit basin size and drawdown (drain) time, and as a percentage of total suspended solids captured, for the same two variables. Regional differences are apparent, driven mainly by variations in rainfall patterns around the country.     

Dialogical Argument as an Interface to Complex Debates

The Magtalo prototype environment harnesses dialogue protocols to support flexible, intuitive interaction with data in complex, contentious domains and provides mechanisms for eliciting structured knowledge. Magtalo represents the first example of an implemented online system that uses a closely specified argument-based dialogue protocol combined with a rich language for representing monologic argument to provide a tool for intuitive user exploration of a disagreement space. This approach also enables the expansion of argument resources through knowledge elicitation, which is structured by the argument dialogue protocol. The continuing aim of our research is to use advances in argumentation theory to push the practice of argumentation technology in providing tools and interfaces that have wide appeal.     

Effects of cocaine on dopamine receptor gene expression: a study in the postmortem human brain

The effects of chronic cocaine exposure on dopamine D1 and D2 receptor gene expression in the human brain were studied in postmortem samples from chronic cocaine abusing and matched control subjects. Using in situ hybridization of receptor autoradiography to examine messenger ribonucleic acid (RNA) and binding sites, respectively, neither D1 nor D2 receptor expression was found to be changed in the nucleus accumbens, caudate, putamen, or substantia nigra of the cocaine-exposed subjects. Although chronic cocaine exposure can produce alterations in dopaminergic neurotransmission, sustained compensatory changes in dopamine receptor expression do not appear to occur in the human.     

Symptom correlates of attentional improvement following hospitalization for a first episode of affective psychosis

BACKGROUND: This study examined patients with a first-episode of affective psychosis during acute and compensated states in order to determine whether changes in attentional functioning over time were accompanied by changes in the severity of psychotic or affective symptoms. METHODS: Attentional performance was measured in patients (n = 27) using the degraded-stimulus continuous Performance Test (CPT) and symptoms were assessed at the time of index hospitalization, and 2 months after discharge. A comparison group of normal volunteers (n = 31) also performed the CPT two months apart. RESULTS: Patients performed significantly worse than controls at the initial testing but not at follow-up. The improvement in attentional performance significantly correlated with decreased severity of manic symptoms. CONCLUSIONS: Results suggest attentional dysfunction is a state-dependent characteristic of mania, and may provide an additional measure of clinical improvement following treatment.