Computational exploration of the relationship between holistic processing and right hemisphere lateralization in featural and configural recognition tasks

Open URL: http://csjarchive.cogsci.rpi.edu/Proceedings/2011/Holistic processing has long been considered as a property of right hemisphere (RH) processing. Nevertheless, recent studies showed reduced holistic processing and increased RH lateralization in Chinese character recognition expertise, suggesting that these two effects may separate. Through computational modeling, in which we implement a theory of hemispheric asymmetry in perception that posits a low frequency bias in the RH and a high frequency bias in the left hemisphere, we show that when the recognition task relies purely on featural information, holistic processing increases whereas RH lateralization decreases with increasing stimulus similarity; there is a negative correlation between them. In contrast, when the task relies purely on configural information, although RH lateralization negatively correlates with stimulus similarity, holistic processing does not correlate with stimulus similarity; there is a positive correlation between them. This suggests that holistic processing and RH lateralization do not always go together, depending on the task requirements.postprintThe 33rd Annual Meeting of the Cognitive Science Society (CogSci 2011), Boston, MA., 20-23 July 2011. In Proceedings of the 33rd CogSci, 2011, p. 2592-259

A multi-lamp heliodon for architectural schools

Heliodons have been developed to simulate sunlight direction in relation to a building model. For placing the building model, heliodons can be divided into two categories. In one category, the model is to be tilted, and normally also rotated [1,2,3]. In the other category, the model is to be placed horizontally, and normally also stationary [4,5,6]. The later category of heliodons, with a horizontally placed building model, and with the simulated sunlight moving around it, will certainly help architectural students visualise the change of sunlight direction around a building and the related effect on insolation and shading. Furthermore, in both categories, there are heliodons developed [7,8] to examine nnual nsolation/shading on massing models by putting red, green, blue lamps (i.e. dichromatic lamps) respectively at positions for June, September/ March, December, thus improving the capability of the heliodons. In the pursuit of a heliodon capable of demonstrating solar movement, offering the speed of operation as demanded by architectural schools, and occupying a space generally affordable, and primarily suitable for use to test buildings of the climatic region of South China where Hong Kong is located, a multi-lamp heliodon has been developed. This paper reports on this multi-lamp heliodon, which consists of 69 fixed quartz lamps, and 6 dichromatic lamps. It also has the capability of investigating the building model with dichromatic lamps, without the demand of additional space which is always a concern now in architectural schools.http://www.bse.polyu.edu.hk/researchCentre/Fire_Engineering/summary_of_output/journal/IJAS/V1/p.46-58.pd

Peritoneal implantation of ureter in cadaveric renal transplant

Case reportWe report here a case of complication of peritoneal implantation of ureter in cadaveric renal transplant. The patient presented with anuria and delayed graft function. The diagnosis was suspected upon physical examination and radiological investigation. The complication was managed with reimplantation of the ureter into the bladder and the patient recovered with good graft function. We discuss this case, review the literature on this rare complication, and share our suggestions on how it can be prevented.published_or_final_versio

Prediction of 3-d surface topography in ultra-precision machining

2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Dysmenorrhoea among Hong Kong university students: prevalence, impact, and management

published_or_final_versio

On BCFW shifts of integrands and integrals

In this article a first step is made towards the extension of Britto-Cachazo-Feng-Witten (BCFW) tree level on-shell recursion relations to integrands and integrals of scattering amplitudes to arbitrary loop order. Surprisingly, it is shown that the large BCFW shift limit of the integrands has the same structure as the corresponding tree level amplitude in any minimally coupled Yang-Mills theory in four or more dimensions. This implies that these integrands can be reconstructed from a subset of their `single cuts'. The main tool is powercounting Feynman graphs in a special lightcone gauge choice employed earlier at tree level by Arkani-Hamed and Kaplan. The relation between shifts of integrands and shifts of its integrals is investigated explicitly at one loop. Two particular sources of discrepancy between the integral and integrand are identified related to UV and IR divergences. This is cross-checked with known results for helicity equal amplitudes at one loop. The nature of the on-shell residue at each of the single-cut singularities of the integrand is commented upon. Several natural conjectures and opportunities for further research present themselves.Comment: 43 pages, 6 figures, v2: minor improvement in exposition, typos fixed, bibliography update

Hepatocyte-specific activation of NF-κB does not aggravate chemical hepatocarcinogenesis in transgenic mice

The NF-κB signalling pathway plays important roles in liver organogenesis and cardnogenesis. Mouse embryos deficient in IKKβ die in mid-gestation, due to excessive apoptosis of hepatoblasts. Although activation of the NF-κB signalling pathway has been demonstrated in human hepatocellular carcinoma, the role of NF-κB is controversial. Here, we have generated transgenic mice in which a constitutively active form of IKKβ was expressed in a hepatocyte-specific manner. Using electrophoretic mobility shift assay, we documented increased NF-κB activities and up-regulated levels of NF-κB downstream target genes, Bcl-xL and STAT5, in the transgenic mouse livers. These results confirmed that the NF-κB pathway was activated in the livers of the transgenic mice. However, there was no significant difference in tumour formation between transgenic and wild-type mice up to an age of 50 weeks. When we treated the transgenic mice with the chemical carcinogen diethylnitrosamine (DEN), we observed no significant differences in the incidence and size of liver tumours formed in these mice with and without DEN treatment at 35 weeks of age, suggesting that the activated NF-κB pathway in the livers of the transgenic mice did not enhance hepatocarcinogenesis. Interestingly, some of the transient transgenic embryos (E12.5) had abnormal excessive accumulation of nucleated red blood cells in their developing livers. In summary, NF-κB activation in hepatocytes did not significantly affect chemical hepatocarcinogenesis. In addition, the TTR/IKKCA transgenic mice may serve as a useful model for studying the role of NF-κB activation in hepatocarcinogenesis as well as inflammatory and metabolic diseases. Copyright © 2008 Pathological Society of Great Britain and Ireland.postprin

Enhanced survival and regeneration of axotomized retinal ganglion cells by a mixture of herbal extracts

The aim of this study is to investigate the effects of Panax quinquefolius L. extract (PQE), Ginkgo biloba extract (GBE), and Hypericum perforatum extract (HPE), in combination or alone, on the survival and regeneration of axotomized retinal ganglion cells (RGCs) in an optic nerve transection model in adult hamsters. Unilateral transection of the optic nerve was performed to evaluate the effects of herbal extracts on the survival of axotomized RGCs. Effects of the herbal extracts on axonal regeneration of axotomized RGCs, on the other hand, were studied by attaching a peripheral nerve graft onto the transected ocular stump to induce regeneration. Operated animals received daily oral administration of vehicle or herbal extracts (PQE, GBE, and HPE), alone or in combination, for 7 and 21 days, respectively, in the survival and regeneration experiments. Surviving and regenerating RGCs were retrogradely labeled with Fluoro-Gold. The eyes were then enucleated and the retinas were flat-mounted for the counting of the labeled RGCs. Treatment with PQE, GBE and HPE alone failed to offer neuroprotection to injured RGCs. However, treatment with Menta-FX, a mixture of PQE, GBE, and HPE, significantly augmented RGC survival 7 days postaxotomy. Treatment with Menta-FX also induced a significant (87%) increase in the number of regenerating RGCs 21 days after optic nerve transection. This study demonstrates that herbs can act as a potential neuroprotective agent for damaged RGCs. It also suggests that the therapeutic value of herbal remedies can be maximized by the use of mixtures of appropriate herbs.published_or_final_versio

Final report of the Construction Industry Institute, Hong Kong research project on reinventing the Hong Kong construction industry for its sustainable development

Author name used in this publication: Andrew N. BaldwinAuthor name used in this publication: Y. H. ChiangAuthor name used in this publication: Joyce W. S. CheungAuthor name used in this publication: Joanne W. S. NgConstruction Industry Institute-Hong Kong Report, no. 132008-2009 > Academic research: not refereed > Research book or monograph (author)Other Versio

A Definitive Signal of Multiple Supersymmetry Breaking

If the lightest observable-sector supersymmetric particle (LOSP) is charged and long-lived, then it may be possible to indirectly measure the Planck mass at the LHC and provide a spectacular confirmation of supergravity as a symmetry of nature. Unfortunately, this proposal is only feasible if the gravitino is heavy enough to be measured at colliders, and this condition is in direct conflict with constraints from big bang nucleosynthesis (BBN). In this work, we show that the BBN bound can be naturally evaded in the presence of multiple sectors which independently break supersymmetry, since there is a new decay channel of the LOSP to a goldstino. Certain regions of parameter space allow for a direct measurement of LOSP decays into both the goldstino and the gravitino at the LHC. If the goldstino/gravitino mass ratio is measured to be 2, as suggested by theory, then this would provide dramatic verification of the existence of multiple supersymmetry breaking and sequestering. A variety of consistent cosmological scenarios are obtained within this framework. In particular, if an R symmetry is imposed, then the gauge-gaugino-goldstino interaction vertices can be forbidden. In this case, there is no bound on the reheating temperature from goldstino overproduction, and thermal leptogenesis can be accommodated consistently with gravitino dark matter.Comment: 10 pages, 5 figures, title changed to match the version published in JHE