Laser Sintering Fabrication of Highly Porous Models Utilizing Water Leachable Filler-Experimental Investigation into Process Parameters

The authors are developing a laser sintering process to fabricate highly porous models with such high porosities as 90% and more. In the process, water-soluble filler is mixed with designated plastic powder and leached out after laser sintering process is finished to generate pores where the grains used to exist. Previously, the authors reported successful application of this technology on a tissue engineering scaffold. However, relationship between process parameters and obtained results has not been clarified. This paper reports experimental investigation into effects of optimizing process parameters such as mixture, grain size of the filler on resultant porosity, pore size and process resolutionMechanical Engineerin

Conscious Perception as Integrated Information Patterns in Human Electrocorticography

A significant problem in neuroscience concerns the distinction between neural processing that is correlated with conscious percepts from processing that is not. Here, we tested if a hierarchical structure of causal interactions between neuronal populations correlates with conscious perception. We derived the hierarchical causal structure as a pattern of integrated information, inspired by the integrated information theory (IIT) of consciousness. We computed integrated information patterns from intracranial electrocorticography (ECoG) from six human neurosurgical patients with electrodes implanted over lateral and ventral cortices. During recording, subjects viewed continuous flash suppression (CFS) and backward masking (BM) stimuli intended to dissociate conscious percept from stimulus, and unmasked suprathreshold stimuli. Object-sensitive areas revealed correspondence between conscious percepts and integrated information patterns. We quantified this correspondence using unsupervised classification methods that revealed clustering of visual experiences with integrated information, but not with broader information measures including mutual information and entropy. Our findings point to a significant role of locally integrated information for understanding the neural substrate of conscious object perception

Long-term monitoring of the short period SU UMa-type dwarf nova, V844 Herculis

We report on time-resolved CCD photometry of four outbursts of a short-period SU UMa-type dwarf nova, V844 Herculis. We successfully determined the mean superhump periods to be 0.05584(64) days, and 0.055883(3) for the 2002 May superoutburst, and the 2006 April-May superoutburst, respectively. During the 2002 October observations, we confirmed that the outburst is a normal outburst, which is the first recorded normal outburst in V844 Her. We also examined superhump period changes during 2002 May and 2006 April-May superoutbursts, both of which showed increasing superhump period over the course of the plateau stage. In order to examine the long-term behavior of V844 Her, we analyzed archival data over the past ten years since the discovery of this binary. Although photometry is not satisfactory in some superoutbursts, we found that V844 Her showed no precursors and rebrightenings. Based on the long-term light curve, we further confirmed V844 Her has shown almost no normal outbursts despite the fact that the supercycle of the system is estimated to be about 300 days. In order to explain the long-term light curves of V844 Her, evaporation in the accretion disk may play a role in the avoidance of several normal outbursts, which does not contradict with the relatively large X-ray luminosity of V844 Her.Comment: 10 pages, 11 figures, accepted for PAS

Dwarf Novae in the Shortest Orbital Period Regime: I. A New Short Period Dwarf Nova, OT J055717+683226

We report the observation of a new dwarf nova, OT J055717+683226, during its first-ever recorded superoutburst in December 2006. Our observation shows that this object is an SU UMa-type dwarf nova having a very short superhump period of 76.67+/- 0.03 min (0.05324+/-0.00002 d). The next superoutburst was observed in March 2008. The recurrence time of superoutbursts (supercycle) is, hence, estimated to be ~480 d. The supercycle is much shorter than those of WZ Sge-type dwarf novae having supercycles of >~ 10 yr, which are a major population of dwarf novae in the shortest orbital period regime (<~85 min). Using a hierarchical cluster analysis, we identified seven groups of dwarf novae in the shortest orbital period regime. We identified a small group of objects that have short supercycles, small outburst amplitudes, and large superhump period excesses, compared with those of WZ Sge stars. OT J055717+683226 probably belongs to this group.Comment: 14 pages, 11 figures, accepted for publication in PAS

Conscious Perception as Integrated Information Patterns in Human Electrocorticography

A significant problem in neuroscience concerns the distinction between neural processing that is correlated with conscious percepts from processing that is not. Here, we tested if a hierarchical structure of causal interactions between neuronal populations correlates with conscious perception. We derived the hierarchical causal structure as a pattern of integrated information, inspired by the integrated information theory (IIT) of consciousness. We computed integrated information patterns from intracranial electrocorticography (ECoG) from six human neurosurgical patients with electrodes implanted over lateral and ventral cortices. During recording, subjects viewed continuous flash suppression (CFS) and backward masking (BM) stimuli intended to dissociate conscious percept from stimulus, and unmasked suprathreshold stimuli. Object-sensitive areas revealed correspondence between conscious percepts and integrated information patterns. We quantified this correspondence using unsupervised classification methods that revealed clustering of visual experiences with integrated information, but not with broader information measures including mutual information and entropy. Our findings point to a significant role of locally integrated information for understanding the neural substrate of conscious object perception

Radial Overgrowth After Radial Shortening Osteotomies for Skeletally Immature Patients With Kienböck's Disease

Purpose: We hypothesized that radial shortening osteotomy (radial shortening) for skeletally immature patients with Kienböck's disease would induce overgrowth of the radius. The purpose of this study was to determine the effect of radial shortening on radial growth in skeletally immature patients with Kienböck's disease and to clarify the relationship between the postoperative growth alterations and the clinical results. Methods: Eight wrists of 8 skeletally immature patients with Kienböck's disease were treated with radial shortening. There were 3 males and 5 females, ranging in age from 11 to 18 (mean, 14) years old. All patients presented with open physis and negative ulnar variance. The length of the radial shortening equaled the amount of negative ulnar variance. Clinical assessment was based on the modified Nakamura scoring system. Radiographic assessment, including Lichtman's stages, ulnar variance, carpal height ratio, radial inclination, and volar tilt, was performed preoperation, immediately after surgery, and at follow-up. A difference in ulnar variance of more than 2 mm between these time points was considered to be overgrowth. Statistical comparisons were performed using paired t-tests. Results: At a mean follow-up period of 69 months, the mean clinical score was 19.7 of 21 maximum points, with all wrists rated as excellent. Radiographically, no progression of Lichtman stage was found in any patient. At follow-up, the X-ray and MRI findings indicated lunate revascularization in all patients. Four of the 8 were recognized to have had overgrowth in the operated radius. On the other hand, other radiographic parameters showed no significant changes at follow-up. The occurrence of postoperative radial overgrowth did not significantly affect the clinical scores. Conclusions: The current results suggest the probability of occurrence in the overgrowth of the radius in skeletally immature patients with Kienböck's disease treated with radial shortening. The postoperative radial overgrowth after this osteotomy had no effects on clinical and other radiographic outcomes

Indications and technical details of sublobar resections for small-sized lung cancers based on tumor characteristics

With the recent increase in small-sized lung cancers, sublobar resection and minimally invasive surgeries are becoming preferred. In particular, the detection of ground-glass nodules (GGNs) on high-resolution computed tomography has increased. Although lobectomy has been considered a standard procedure for treating lung cancer, sublobar resections have been indicated for treating GGN-dominant small-sized lung cancers. Wedge resection and segmentectomy have generally been performed as sublobar resection; however, each procedure has some technical advantages and disadvantages. Although anatomical resection as a segmentectomy is a complicated procedure, it has recently been increasingly performed with the accurate anatomical grasp using three-dimensional computed tomography and the identification of the intersegmental plane. Other procedures involving the use of newer technologies can also be performed. Individualized sublobar resection might be a suitable procedure for small-sized lung cancer with the appropriate selection of procedures based on each tumor’s characteristics and improving the methods to overcome some technical difficulties