Multimodal Registration Procedure for the Initial Spatial Alignment of a Retinal Video Sequence to a Retinal Composite Image

Accurate placement of lesions is crucial for the effectiveness and safety of a retinal laser photocoagulation treatment. Computer assistance provides the capability for improvements to treatment accuracy and execution time. The idea is to use video frames acquired from a scanning digital ophthalmoscope (SDO) to compensate for retinal motion during laser treatment. This paper presents a method for the multimodal registration of the initial frame from an SDO retinal video sequence to a retinal composite image, which may contain a treatment plan. The retinal registration procedure comprises the following steps: 1) detection of vessel centerline points and identification of the optic disc; 2) prealignment of the video frame and the composite image based on optic disc parameters; and 3) iterative matching of the detected vessel centerline points in expanding matching regions. This registration algorithm was designed for the initialization of a real-time registration procedure that registers the subsequent video frames to the composite image. The algorithm demonstrated its capability to register various pairs of SDO video frames and composite images acquired from patients.

Real-Time Multimodal Retinal Image Registration for a Computer Assisted Laser Photocoagulation System

An algorithm for the real-time registration of a retinal video sequence captured with a scanning digital ophthalmoscope (SDO) to a retinal composite image is presented. This method is designed for a computer-assisted retinal laser photocoagulation system to compensate for retinal motion and hence enhance the accuracy, speed, and patient safety of retinal laser treatments. The procedure combines intensity and feature-based registration techniques. For the registration of an individual frame, the translational frame-to-frame motion between preceding and current frame is detected by normalized cross correlation. Next, vessel points on the current video frame are identified and an initial transformation estimate is constructed from the calculated translation vector and the quadratic registration matrix of the previous frame. The vessel points are then iteratively matched to the segmented vessel centerline of the composite image to refine the initial transformation and register the video frame to the composite image. Criteria for image quality and algorithm convergence are introduced, which assess the exclusion of single frames from the registration process and enable a loss of tracking signal if necessary. The algorithm was successfully applied to ten different video sequences recorded from patients. It revealed an average accuracy of 2.47 ± 2.0 pixels (∼23.2 ± 18.8 μm) for 2764 evaluated video frames and demonstrated that it meets the clinical requirements.

Use of a computerized closed-loop sodium nitroprusside titration system for antihypertensive treatment after open heart surgery

This study evaluates the clinical applicability of administering sodium nitroprusside by a closed-loop titration system compared with a manually adjusted system. The mean arterial pressure (MAP) was registered every 10 and 30 sec during the first 150 min after open heart surgery in 20 patients (group 1: computer regulation) and in ten patients (group 2: manual regulation). The results (16,343 and 2,912 data points in groups 1 and 2, respectively), were then analyzed in four time frames and five pressure ranges to indicate clinical efficacy. Sixty percent of the measured MAP in both groups was within the desired +/- 10% during the first 10 min. Thereafter until the end of observation, the MAP was maintained within +/- 10% of the desired set-point 90% of the time in group 1 vs. 60% of the time in group 2. One percent and 11% of data points were +/- 20% from the set-point in groups 1 and 2, respectively (p less than .05, chi-square test). The computer-assisted therapy provided better control of MAP, was safe to use, and helped to reduce nursing demands.

How Entrepreneurs Become Skilled Cultural Operators

Cultural entrepreneurship and symbolic management perspectives portray entrepreneurs as skilled cultural operators and often assume them to be capable from the outset to purposefully use ‘cultural resources' in order to motivate resource-holding audiences to support their new ventures. We problematize this premise and develop a model of how entrepreneurs become skilful cultural operators and develop the cultural competences necessary for creating and growing their ventures. The model is grounded in a case study of an entrepreneur who set up shop and sought to acquire resources in a culturally unfamiliar setting. Our model proposes that two adaptive sensemaking processes - approval-driven sensemaking and autonomy-driven sensemaking - jointly facilitate the gradual development of cultural competences. These processes jointly enable entrepreneurs to gain cultural awareness and calibrate their symbolic enactments. Specifically, while approval-driven sensemaking facilitates recognizing cultural resources to symbolically couple a venture's identity claims more tightly with the cultural frames of targeted audiences and gain legitimate distinctiveness, autonomy-driven sensemaking enables recognizing cultural constraints and more effective symbolic decoupling to shield the venture from constraining cultural frames and defend the venture's autonomy and resources. We conclude the paper with a discussion of the theoretical implications of our study for cultural entrepreneurship and symbolic management research.

Selective cloning, characterization, and production of the Culicoides nubeculosus salivary gland allergen repertoire associated with equine insect bite hypersensitivity

Salivary gland proteins of Culicoides spp. have been suggested to be among the main allergens inducing IgE-mediated insect bite hypersensitivity (IBH), an allergic dermatitis of the horse. The aim of our study was to identify, produce and characterize IgE-binding salivary gland proteins of Culicoides nubeculosus relevant for IBH by phage surface display technology. A cDNA library constructed with mRNA derived from C. nubeculosus salivary glands was displayed on the surface of filamentous phage M13 and enriched for clones binding serum IgE of IBH-affected horses. Ten cDNA inserts encoding putative salivary gland allergens were isolated and termed Cul n 2 to Cul n 11. However, nine cDNA sequences coded for truncated proteins as determined by database searches. The cDNA sequences were amplified by PCR, subcloned into high level expression vectors and expressed as hexahistidine-tagged fusion proteins in Escherichia coli. Preliminary ELISA results obtained with these fusions confirmed the specific binding to serum IgE of affected horses. Therefore, the putative complete open reading frames derived from BLAST analyses were isolated by RACE-PCR and subcloned into expression vectors. The full length proteins expressed in Escherichia coli showed molecular masses in the range of 15.5-68.7 kDa in SDS-PAGE in good agreement with the masses calculated from the predicted protein sequences. Western blot analyses of all recombinant allergens with a serum pool of IBH-affected horses showed their ability to specifically bind serum IgE of sensitized horses, and ELISA determinations yielded individual horse recognition patterns with a frequency of sensitization ranging from 13 to 57%, depending on the allergen tested. The in vivo relevance of eight of the recombinant allergens was demonstrated in intradermal skin testing. For the two characterized allergens Cul n 6 and Cul n 11, sensitized horses were not available for intradermal tests. Control horses without clinical signs of IBH did not develop any relevant immediate hypersensitivity reactions to the recombinant allergens. The major contribution of this study was to provide a repertoire of recombinant salivary gland allergens repertoire from C. nubeculosus potentially involved in the pathogenesis of IBH as a starting basis for the development of a component-resolved serologic diagnosis of IBH and, perhaps, for the development of single horse tailored specific immunotherapy depending on their component-resolved sensitization patterns.

Analysis and mapping of CACNB4, CHRNA1, KCNJ3, SCN2A and SPG4, physiological candidate genes for porcine congenital progressive ataxia and spastic paresis

The cause of porcine congenital progressive ataxia and spastic paresis (CPA) is unknown. This severe neuropathy manifests shortly after birth and is lethal. The disease is inherited as a single autosomal recessive allele, designated cpa. In a previous study, we demonstrated close linkage of cpa to microsatellite SW902 on porcine chromosome 3 (SSC3), which corresponds syntenically to human chromosome 2. This latter chromosome contains ion channel genes (Ca(2+), K(+) and Na(+)), a cholinergic receptor gene and the spastin (SPG4) gene, which cause human epilepsy and ataxia when mutated. We mapped porcine CACNB4, KCNJ3, SCN2A and CHRNA1 to SSC15 and SPG4 to SSC3 with the INRA-Minnesota porcine radiation hybrid panel (IMpRH) and we sequenced the entire open reading frames of CACNB4 and SPG4 without finding any differences between healthy and affected piglets. An anti-epileptic drug treatment with ethosuximide did not change the severity of the disease, and pigs with CPA did not exhibit the corticospinal tract axonal degeneration found in humans suffering from hereditary spastic paraplegia, which is associated with mutations in SPG4. For all these reasons, the hypothesis that CACNB4, CHRNA1, KCNJ3, SCN2A or SPG4 are identical with the CPA gene was rejected.

Genetic diversity among Mycoplasma species bovine group 7: clonal isolates from an outbreak of polyarthritis, mastitis, and abortion in dairy cattle

A comprehensive genetic analysis of 60 Mycoplasma sp. bovine group 7 isolates from different geographic origins and epidemiological settings is presented. Twenty-four isolates were recovered from the joints of calves during sporadic episodes of polyarthritis in geographically distinct regions of Queensland and New South Wales, Australia, including two clones of the type strain PG5O. A further three Australian isolates were also recovered from the tympanic bulla, retropharyngeal lymph node and the lung and another three isolates had unconfirmed histories. Six isolates originated from Germany, Portugal, Nigeria, and France. Twenty-four epidemiologically related isolates of Mycoplasma sp. bovine group 7 were recovered from multiple tissue sites and body fluids of infected calves with polyarthritis, mastitic milk, and from the stomach contents, lung and liver from aborted foetuses in three large, centrally managed dairy herds in New South Wales, Australia. Restriction endonuclease analysis (REA) of genomic DNA differentiated 29 Cfol profiles among these 60 isolates and grouped all 24 epidemiologically related isolates in a defined pattern showing a clonal origin. Three isolates of this clonal cluster were recovered from mastitic milk and the synovial exudate of clinically-affected calves and appeared sporadically for periods up to 18 months after the initial outbreak of polyarthritis indicating a persistent, close association of the organism with cattle in these herds. The Cfol profile representative of the clonal cluster was distinguishable from profiles of isolates recovered from multiple, unrelated cases of polyarthritis in Queensland and New South Wales and from other countries. All 24 isolates from the clonal cluster possessed a plasmid (pBG7AU) with a molecular size of 1022 bp. DNA sequence analysis of pBG7AU identified two open reading frames sharing 81 and 99% DNA sequence similarity with hypothetical replication control proteins A and B respectively, previously described in plasmid pADB201 isolated from M. mycoides subspecies mycoides. Other isolates of bovine group 7, epidemiologically unrelated to the clonal cluster, including two clones of the type strain PG5O, possessed a similar-sized plasmid. These data confirm that Mycoplasma sp. bovine group 7 is capable of migrating to, and multiplying within, different tissue sites within a single animal and among different animals within a herd.

Emotional contagion in team sports and its impact on individual performance – an experimental study

In sport psychology research about emotional contagion in sport teams has been scarce (Reicherts & Horn, 2008). Emotional contagion is a process leading to a specific emotional state in an individual caused by the perception of another individual’s emotional expression (Hatfield, Cacioppo & Rapson, 1994). Apitzsch (2009) described emotional contagion as one reason for collapsing sport teams. The present study examined the occurrence of emotional contagion in dyads during a basketball task and the impact of a socially induced emotional state on performance. An experiment with between-subjects design was conducted. Participants (N=81, ♀=38, M=21.33 years, SD=1.45) were randomly assigned to one of two experimental conditions, by joining a confederate to compose a same gender, ad hoc team. The team was instructed to perform a basketball task as quickly as possible. The between-factor of the experimental design was the confederate’s emotional expression (positive or negative valence). The within-factor was participants’ emotional state, measured pre- and post-experimentally using PANAS (Krohne, Egloff, Kohlmann & Tausch, 1996). The basketball task was video-taped and the number of frames participants needed to complete the task was used to determine the individual performance. The confederate’s emotional expression was appraised in a significantly different manner across both experimental conditions by participants and video raters (MC). Mixed between-within subjects ANOVAs were conducted to examine the impact of the two conditions on participants’ scores on the PANAS subscales across two time periods (pre- and post-experimental). No significant interaction effects but substantial main effects for time were found on both PANAS subscales. Both groups showed an increase in positive and a reduction in negative PANAS scores across these two time periods. Nevertheless, video raters assessment of the emotional states expressed by participants was significantly different between the positive (M=3.23, SD=0.45) and negative condition (M=2.39, SD=0.53; t=7.64, p<.001, eta squared=.43). An independent-samples t-test indicated no difference in performance between conditions. Furthermore, no significant correlation between the extent of positive or negative emotional contagion and the number of frames was observed. The basketball task lead to an improvement of the emotional state of participants, independently of the condition. Even though participants PANAS scores indicated a tendency to emotional contagion, it was not statistically significant. This could be explained by the low task duration of approximately three minutes. Moreover, the performance of participants was unaffected by the experimental condition or the extent of positive or negative emotional contagion. Apitzsch, E. (2009). A case study of a collapsing handball team. In S. Jern & J. Näslund (Eds.), Dynamics within and outside the lab. Proceedings from The 6th Nordic Conference on Group and Social Psychology, May 2008, Lund, pp. 35-52. Hatfield, E., Cacioppo, J. T. & Rapson, R. L. (1994). Emotional contagion. Cambridge: University Press. Krohne, H. W., Egloff, B., Kohlmann, C.-W. & Tausch, A. (1996). Untersuchungen mit einer deutschen Version der „Positive und Negative Affect Schedule“ (PANAS). Diagnostica, 42 (2), 139-156. Reicherts, M. & Horn, A. B. (2008). Emotionen im Sport. In W. Schlicht & B. Strauss (Eds.), Enzyklopädie der Psychologie. Grundlagen der Sportpsychologie (Bd. 1) (S. 563-633). Göttingen: Hogrefe.

Identification and expression of different dehydrin subclasses involved in the drought response of Trifolium repens

Reverse transcribed RNAs coding for YnKn, YnSKn, SKn, and KS dehydrin types in drought-stressed white clover (Trifolium repens) were identified and characterized. The nucleotide analyses revealed the complex nature of dehydrin-coding sequences, often featured with alternative start and stop codons within the open reading frames, which could be a prerequisite for high variability among the transcripts originating from a single gene. For some dehydrin sequences, the existence of natural antisense transcripts was predicted. The differential distribution of dehydrin homologues in roots and leaves from a single white clover stolon under normal and drought conditions was evaluated by semi-quantitative RT-PCR and immunoblots with antibodies against the conserved K-, Y- and S-segments. The data suggest that different dehydrin classes have distinct roles in the drought stress response and vegetative development, demonstrating some specific characteristic features. Substantial levels of YSK-type proteins with different molecular weights were immunodetected in the non-stressed developing leaves. The acidic SK2 and KS dehydrin transcripts exhibited some developmental gradient in leaves. A strong increase of YK transcripts was documented in the fully expanded leaves and roots of drought-stressed individuals. The immunodetected drought-induced signals imply that Y- and K-segment containing dehydrins could be the major inducible Late Embryogenesis Abundant class 2 proteins (LEA 2) that accumulate predominantly under drought.

Internet video telephony allows speech reading by deaf individuals and improves speech perception by cochlear implant users

OBJECTIVE To analyze speech reading through Internet video calls by profoundly hearing-impaired individuals and cochlear implant (CI) users. METHODS Speech reading skills of 14 deaf adults and 21 CI users were assessed using the Hochmair Schulz Moser (HSM) sentence test. We presented video simulations using different video resolutions (1280 × 720, 640 × 480, 320 × 240, 160 × 120 px), frame rates (30, 20, 10, 7, 5 frames per second (fps)), speech velocities (three different speakers), webcameras (Logitech Pro9000, C600 and C500) and image/sound delays (0-500 ms). All video simulations were presented with and without sound and in two screen sizes. Additionally, scores for live Skype™ video connection and live face-to-face communication were assessed. RESULTS Higher frame rate (>7 fps), higher camera resolution (>640 × 480 px) and shorter picture/sound delay (<100 ms) were associated with increased speech perception scores. Scores were strongly dependent on the speaker but were not influenced by physical properties of the camera optics or the full screen mode. There is a significant median gain of +8.5%pts (p = 0.009) in speech perception for all 21 CI-users if visual cues are additionally shown. CI users with poor open set speech perception scores (n = 11) showed the greatest benefit under combined audio-visual presentation (median speech perception +11.8%pts, p = 0.032). CONCLUSION Webcameras have the potential to improve telecommunication of hearing-impaired individuals.

Frames in the Ethiopian Debate on Biofuels

Biofuel production, while highly contested, is supported by a number of policies worldwide. Ethiopia was among the first sub-Saharan countries to devise a biofuel policy strategy to guide the associated demand toward sustainable development. In this paper, I discuss Ethiopia’s biofuel policy from an interpretative research position using a frames approach and argue that useful insights can be obtained by paying more attention to national contexts and values represented in the debates on whether biofuel production can or will contribute to sustainable development. To this end, I was able to distinguish three major frames used in the Ethiopian debate on biofuels: an environmental rehabilitation frame, a green revolution frame and a legitimacy frame. The article concludes that actors advocating for frames related to social and human issues have difficulties entering the debate and forming alliances, and that those voices need to be included in order for Ethiopia to develop a sustainable biofuel sector.

Conservation of amino acid transporters in fungi, plants and animals

When comparing the transporters of three completely sequenced eukaryotic genomes - Saccharomyces cerevisiae, Arabidopsis thaliana and Homo sapiens - transporter types can be distinguished according to phylogeny, substrate spectrum, transport mechanism and cell specificity. The known amino acid transporters belong to five different superfamilies. Two preferentially Na+-coupled transporter superfamilies are not represented in them yeast and Arabidopsis genomes, whereas the other three groups, which often function as H+-coupled systems, have members in all investigated genomes. Additional superfamilies exist for organellar transport, including mitochondrial and plastidic carriers. When used in combination with phylogenetic analyses, functional comparison might aid our prediction of physiological functions for related but uncharacterized open reading frames.