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We report a switching model that directly explains the change in activation energy (EAC) at different RESET stop voltages (Vstop) in HfO2-based resistive random access memory devices. The dependenc...

A gradual electroforming process was implemented on the pristine Pt/HfOx/Cu/Pt structure to realize volatile threshold switching characteristics of a diffusive memristor. The reported devices exhibit stable unidirectional threshold switching properties with high selectivity of >107 and ultralow OFF current of ∼100 fA for over 104 endurance cycles. Nucleation theory on spheroidal-shaped metallic filament growth is used to extensively discuss the structural changes of the device after gradual forming treatments by analyzing the applied bias amplitude dependency of the finite delay time required by the device to turn ON under external electric field. On the other hand, the Rayleigh instability model was implemented for the aforementioned spheroidal metallic nucleus to explain the relaxation dynamics of the device. It was shown that the relaxation time of the device depends on the initial profile of the nucleus within the insulating layer. The broadening of the ON current distribution of the device was observed during the device endurance test. This is correlated to the presence of a random telegraph signal (RTS) during the ON state of the device. ASTAR (Agency for Sci., Tech. and Research, S’pore) Accepted version

Techniques for estimating cloud motion and stability for intra-hour forecasting using a ground-based sky imaging system are presented. A variational optical flow (VOF) technique was used to determine the sub-pixel accuracy of cloud motion for every pixel. Cloud locations up to 15 min ahead were forecasted by inverse mapping of the cloud map. A month of image data captured by a sky imager at UC San Diego was analyzed to compare the accuracy of VOF forecast with cross-correlation method (CCM) and image persistence method. The VOF forecast with a fixed smoothness parameter was found to be superior to image persistence forecast for all forecast horizons for almost all days and outperform CCM forecast with an average error reduction of 39%, 21%, 19%, and 19% for 0, 5, 10, and 15 min forecasts respectively. Optimum forecasts may be achieved with forecast-horizon-dependent smoothness parameters. In addition, cloud stability and forecast confidence was evaluated by correlating point trajectories with forecast error. Point trajectories were obtained by tracking sub-sampled pixels using optical flow field. Point trajectory length in mintues was shown to increase with decreasing forecast error and provide valuable information for cloud forecast confidence at forecast issue time.

We investigate a stable and wavelength-tunable erbium-doped fiber laser with single-longitudinal-mode by using multi-ring architecture and silicon micro-ring-resonator (SMRR). Here, the output wavelength range of 1529.8 nm to 1561.8 nm can be obtained.

Solar irradiance forecast accuracy of a ground-based sky imaging system currently being developed at UC San Diego is analyzed by assessing its performance on thirty-one consecutive days of historical data collected during winter. Sky images were taken every 30 s, and then processed to determine cloud cover, optical depth (thick or thin), and mean cloud field velocity. Cloud locations were forecasted using a frozen cloud advection method at 30 s intervals up to a forecast horizon of 15 min. During the analysis period, cloud field matching errors, which monotonically increase as a function of forecast horizon, did not exceed 30% over the sky imager’s field-of-view. On average, frozen cloud advection forecasts were found to perform superiorly to image persistence forecasts for all forecast horizons during the analysis period. Six (later eleven) distributed pyranometer installations over the UCSD campus provided 1-s instantaneous GHI measurements with which to validate irradiance forecasts. Excluding clear days or days with small forecast sample size, sky imager irradiance forecasts were found to perform the same as or better than clear sky index (clear-sky normalized GHI) persistence forecasts on 4 out of 24 days for 5-min forecasts, 8 out of 23 days for 10-min forecasts, and 11 out of 23 days for 15-min forecasts. Furthermore, visual comparison of forecast irradiance with measured irradiance revealed the ability to accurately predict cloud-induced irradiance fluctuations, which persistence forecasts cannot offer. An additional month of data collected during summer was analyzed to evaluate performance consistency during a time period with different meteorological conditions. Due to sky conditions favoring persistence forecast and challenges with cloud detection, sky imager forecasts were unable to surpass persistence forecasts for all 32 days for 5-min forecasts and only succeeded on 1 day for 10-min forecasts. However, bulk errors indicated consistency with winter forecasts, with rRMSE of 24.3% (20.0% for winter) and 27.7% (22.9%) for 5- and 10-min forecasts, respectively. A discussion of the challenges and sources of error applicable to the sky imaging system used is also presented, as well as future research intended to address potential areas of improvement.

The performance of the Total Sky Imager (TSI) and University of California, San Diego Sky Imager (USI) instruments has been evaluated using correlation and dispersion metrics applied to clear sky index. The TSI was located at a 48MW PV plant in Nevada, USA, and the USI was located at the UCSD campus in San Diego, USA. Distributed pyranometer measurements over several square kilometers were available at both locations to provide spatial averages of irradiance. Clear sky index was forecast for a 15 minute horizon at 30 sec. intervals, and the correlation and Euclidean dispersion were evaluated. A persistence forecast was generated for each location to provide a reference for comparison. For the aggregate dataset, the forecast performance of the USI exceeded that of persistence beyond the 10 minute forecast horizon, whereas the TSI did not show skill over persistence. For the period of study, the USI gave correlations of clear sky index between 0.70 and 0.82, whereas the TSI provided correlations between 0.55 and 0.69. Overall, the mean value and the trend of the correlation results were more consistent for the USI than the TSI on the days evaluated. It is concluded that the USI is a more reliable solar resource assessment instrument for the wide range of atmospheric conditions evaluated.

Intra-hour forecasting with a total sky imager at the UC San Diego solar energy testbed Chi Wai Chow 1 , Bryan Urquhart 1 , Matthew Lave 1 , Anthony Dominguez 1 , Jan Kleissl 1 , Janet Shields 2 , Byron Washom 3 Department of Mechanical and Aerospace Engineering Marine Physical Laboratory, Scripps Institution of Oceanography Director, Strategic Energy Initiatives University of California, San Diego Phone: +1 858 534 8087 email: jkleissl@ucsd.edu Abstract A method for intra-hour, sub-kilometer cloud forecasting and irradiance nowcasting using a ground- based sky imager at the University of California, San Diego is presented. Sky images taken every 30 seconds were processed to determine sky cover using a clear sky library and sunshine parameter. From a two-dimensional cloud map generated from coordinate-transformed sky cover, cloud shadows at the surface were estimated. Limited validation on four partly cloudy days showed that (binary) cloud conditions were correctly nowcast 70% of the time for a network of six pyranometer ground stations spread out over an area of 2 km 2 . Cloud motion vectors were generated by cross-correlating two consecutive sky images. Cloud locations up to five minutes ahead were forecasted by advection of the two-dimensional cloud map. Cloud forecast error increased with increasing forecast horizon due to high cloud cover variability over the coastal site.

Objective First report of a term neonate with coexistent congenital cystic adenomatoid malformation (CCAM) of the lung and alveolar capillary dysplasia (ACD). Methods and design Case report and literature review. Our institutional review board waived the need for consent. Setting We describe a term neonate with antenatally diagnosed CCAM and persistent pulmonary hypertension of the newborn (PPHN) who underwent right upper lobe resection on day 9 of life. Histology confirmed CCAM but closer examination also showed ACD. Postoperatively pulmonary hypertension persisted despite high-frequency oscillation and inhaled nitric oxide, and she was placed on extracorporeal membrane oxygenation. Due to the lack of any improvement, intensive care treatment was withdrawn 4 days later. Conclusions This is the first description of an association between these two rare malformations. Although a causative link between CCAM and ACD is possible, it is unlikely. ACD should always be considered as a cause of severe PPHN when persistent beyond 10 days, even if another etiology of PPHN is present.

Aims: Lymphadenoma of the salivary gland is a rare neoplasm that has not been properly characterized. This study describes the clinicopathological features of three cases. Methods and results: All three patients were males, ranging in age from 13 to 57 years. Two presented with a parotid mass, and one a preauricular mass. The tumours were well circumscribed, comprising anastomosing trabeculae, solid tubules, glands or basaloid islands of epithelium with or without cyst formation, accompanied by a prominent lymphoid stroma lacking sinuses. Large reactive lymphoid follicles were found in two cases. The epithelial cells were bland-looking to mildly atypical. Immunostaining demonstrated dual luminal cell and abluminal basal cell differentiation, with the former being often subtle and highlighted only by immunostaining for epithelium membrane antigen or CAM 5.2, and the latter being highlighted by p63 immunostain. Conclusions: Although there is some variation in the histological pattern from case to case, lymphadenoma is a morphologically recognizable salivary gland adenoma characterized by a dense lymphoid infiltrate. Lack of familiarity with this tumour may lead to misdiagnosis as myoepithelial sialadenitis, lymphoma, metastatic carcinoma in lymph node or lymphoepithelial carcinoma.

Background Syk, an immune regulatory tyrosine kinase, plays a role in inflammatory disease processes. We recently reported a role for epithelial expression of Syk in the airways hyper-responsiveness in response to air pollution in a mouse model of asthma. The aim of this study was to further investigate the role of Syk in airway contractility in response to methacholine (MCh) and particulate matter (PM) air pollutants, in the absence of underlying inflammation. Methods We used Sykflox/flox//rosa26CreERT2 conditional Syk knockout mice to evaluate respiratory mechanics and MCh responsiveness following PM exposure in vivo using the ventilator-based flexiVent® system. Results While total and differential cell counts in bronchoalveolar lavage fluid were similar between the Sykflox/flox and Sykdel/del mice, central airways respiratory resistance (RN) to MCh was significantly augmented following PM exposure between Syk-intact (Sykflox/flox) and Syk-deficient (Sykdel/del) mice (RN(max): 2.06 ± 0.29 vs. 1.29 ± 0.10, respectively; p

Background The inflammatory immune response associated with allergic airway inflammation in asthma involves T helper type 2 (Th2) immunity. Given the data that a newly described late activator antigen-presenting cell (LAPC) population promotes Th2 immunity in viral infections, we undertook studies to investigate whether LAPCs have a pathogenic role in allergic airway inflammation. Methods We employed acute ovalbumin (OVA) and house dust mite (HDM) sensitization and challenge models to establish allergic airway inflammation in mice, followed by the analysis of lungs and draining lymph node (DLN) cell infiltrates, immunoglobulin E (IgE) production, and airway hyper-responsiveness (AHR). We tested whether adoptive transfer of LAPCs isolated from mice with established allergic airway inflammation augments the development of sensitization in naive mice. Results We provide evidence that in both OVA and HDM mouse models of allergic inflammation, LAPCs accumulate in the lungs and draining lymph nodes (DLNs), concomitant with the onset of lung pathology, allergen-specific IgE production, eosinophilia, and Th2 cytokine production. Adoptive transfer experiments using OVA-activated LAPCs reveal exacerbation of disease pathology with an increase in lung inflammatory cells, eosinophilia, circulating IgE, Th2 cytokine production, and a worsening of AHR. OVA-activated LAPCs preferentially increased GATA-3 induction in naive CD4+ T cells. Conclusions Together, these data suggest an important role for LAPCs in polarizing the Th2 response in mouse models of allergic airway inflammation.

Retrieval effectiveness depends on how terms are extracted and indexed. For Chinese text (and others like Japanese and Korean), there are no space to delimit words. Indexing using hybrid terms (i.e. words and bigrams) were able to achieve the best precision amongst homogenous terms at a lower storage cost than indexing with bigrams. However, this was tested with conjunctive queries. Here, we extended the weighted Boolean models using fuzzy and p-norm measures, as well as the vector space model using the cosine measure, for processing hybrid terms. Our evaluation shows that all IR models using hybrid terms achieve better average precision over those using words. Across different recall values, the weighted Boolean model using fuzzy measures with hybrid terms achieve consistently about 8% higher than those using words. The vector space model using the cosine measures with hybrid terms achieved the best improvement in the average recall and precision.

Passive optical network (PON) is widely considered as a promising technology for the fiber-to-the-home (FTTH). In this talk, we will review some of the early works on the second-stage next-generation passive-optical-network (NG-PON2). Then, we will focus our attention on the time wavelength division multiplexed PON (TWDM-PON), which is believed to be a promising candidate for the early stage deployment of NG-PON2.

Spontaneous rupture of hepatocellular carcinoma with intraperitoneal haemorrhage is a life-threatening condition. Intraperitoneal spread of the tumour after rupture occurs uncommonly. We report two cases of curative management for recurrent tumour implantation after ruptured hepatocellular carcinoma. The two patients presented with ruptured hepatocellular carcinoma and were treated with transarterial embolisation in the acute episode. Interval partial hepatectomy of the carcinoma was performed after the acute episodes. The first patient presented with a large epigastric mass 2 years after rupture. The mass was found to be adherent to the stomach and omentum. Distal gastrectomy was performed. The second patient presented with a right upper quadrant mass 4 months after rupture, and had a huge tumour attached to the ascending colon. Right hemicolectomy and omentectomy were performed. On histological examination, both tumours were confirmed to be recurrent hepatocellular carcinomas with clear surgical margins. After resection, both patients had no tumour recurrence at 1 year and 3 years, respectively.

This chapter discusses the use of ground-based visible wavelength imagery for short-term forecasting of solar-power output. It begins with selected applications of short-term forecasting to both transmission- and distribution-scale generation. The hardware used in sky-imaging systems is next presented, providing technical and historical information on system optics and sensory equipment (e.g., charge-coupled devices). A high-quality sky-imaging system designed by the authors (the USI) is then briefly examined. The core of the chapter consists of describing sky-imagery analysis techniques, followed by their application to a large solar-power plant. The techniques used to detect clouds, determine their height, and estimate their motion are explained. Application of these methods to generate a power forecast is presented in a case study of a 48 MW solar-power plant, for which a week of data was analyzed. The results are discussed and ideas for improvement are presented. Finally, recommendations for advancing ground-based visible-wavelength imagery and forecast performance are presented.

A high spectral-efficiency M-ary amplitude-shift-keying M-ary quadrature-amplitude-modulation orthogonal-frequency-division-multiplexing (MASK-MQAM-OFDM) coding is proposed. Hence, optical wired and wireless systems can be integrated seamlessly.

We describe 22 patients who presented between the ages of 4 and 14 years with gradual onset of malaise and pain at the sites of multiple bone lesions. The symptoms from the bone lesions were sometimes sequential in onset and often relapsing. The radiological findings were typical of osteomyelitis. Radioisotope bone scans identified some clinically silent lesions. Bone biopsies were performed in 20 patients and the changes of osteomyelitis were seen in 17; microbiological culture was positive in only one. Seven patients had polyarthritis, two had palmoplantar pustulosis and one had psoriasis. Some symptomatic relief was obtained with anti-inflammatory agents and, to a less extent, with antibiotics. No patient had primary immunodeficiency. The mean duration of symptoms from the bone lesions was two years (1 to 4). When arthritis was present the joint symptoms lasted considerably longer (mean 7 years; range 4 to 10). The long-term prognosis was generally good. There was no evidence of altered bone growth or abnormal joint development. One patient developed a progressive kyphosis requiring fusion, but no other surgical intervention was necessary.

Slow-transit constipation (STC) is recognized in children but the etiology is unknown. Abnormalities in substance P (SP), vasoactive intestinal peptide (VIP) and nitric oxide (NO) have been implicated. The density of nerve fibers in circular muscle containing these transmitters was examined in colon from children with STC and compared to other pediatric and adult samples.Fluorescence immunohistochemistry using antibodies to NO synthase (NOS), VIP and SP was performed on colonic biopsies (transverse and sigmoid colon) from 33 adults with colorectal cancer, 11 children with normal colonic transit and anorectal retention (NAR) and 51 with chronic constipation and slow motility in the proximal colon (STC). The percentage area of nerve fibers in circular muscle containing each transmitter was quantified in confocal images.In colon circular muscle, the percentage area of nerve fibers containing NOSVIPSP (6 : 2 : 1). Pediatric groups had a higher density of nerve fibers than adults. In pediatric samples, there were no regional differences in NOS and VIP, while SP nerve fiber density was higher in sigmoid than proximal colon. STC children had lower SP and VIP nerve fiber density in the proximal colon than NAR children. Twenty-three percent of STC children had low SP nerve fiber density.There are age-related reductions in nerve fiber density in human colon circular muscle. NOS and VIP do not show regional variations, while SP nerve fiber density is higher in distal colon. 1/3 of pediatric STC patients have low SP or VIP nerve fiber density in proximal colon.

We reviewed our experience of endomyocardial biopsy performed on 21 symptomatic infants and children with cardiomyopathy. Clinical congestive cardiomyopathy was noted in 18 patients, 2 had hypertrophic cardiomyopathy, and 1 a restrictive cardiomyopathy. The biopsy findings led to a diagnosis of hemochromatosis in one patient, Adriamycin cardiomyopathy in another, and lymphocytic myocarditis in a third. Five patients had features of endocardial fibroelastosis, one endomyocardial fibrosis, and a further one, a mitochrondrial abnormality. In 11 patients normal or nonspecific features were seen. There were 2 myocardial perforations, both patients being successfully resuscitated. Endomyocardial biopsy, although occasionally hazardous, may sometimes provide valuable information which may lead to a diagnosis, facilitate treatment, and be of prognostic value. Despite the low positive yield, it may still be indicated in selected patients, in view of the seriousness and often poor prognosis of this disorder: 5 of our study group subsequently died.

The features of three babies with lethal perinatal osteogenesis imperfecta resulting from the substitution of glycine by arginine in the pro alpha 1(I) chain of type I procollagen were studied. The babies were heterozygous for this substitution at residue 391 in case 1 (0I24), 667 in case 2 (0I51), and 976 in case 3 (0I30). They were all small, term babies who died soon after birth. The ribs were broad and continuously beaded in 0I24, discontinuously beaded in 0I51, and slender with few fractures in 0I30. The overall radiographical classifications were type IIA in 0I24, IIA/IIB in 0I51, and IIB in 0I30. Histological examination confirmed that the long bones were misshapen and porotic. The calcified cartilage trabeculae were covered with an abnormally thin layer of osteoid and the bone trabeculae were thin and basophilic. There was no evidence of lamellar bone or Haversian systems. The osteoblasts remained relatively large and closely spaced. These babies shared many phenotypic features, but differences in the radiographical appearance of the ribs and long bones suggested that there was a gradient of bone modelling capacity from the slender and overmodelled bones in 0I30 to the absence of modelling in 0I24.

Nasal dermoid sinus cysts are uncommon congenital anomalies presenting either as cysts or sinuses. They are frequently associated with extension into the intracranial space, requiring craniotomy for adequate resection. At the Royal Children's Hospital in Melbourne, Australia, we have managed 25 patients with nasal dermoid sinus cysts over 8 years and present details of clinical features, preoperative assessment, and surgical management. Six patients presented with infection, including 1 with osteomyelitis. Four of our patients had intracranial extension of their lesions, and all were treated successfully with tailored investigation and appropriate surgical procedures. Insights into diagnosis, investigation, and surgery are offered to facilitate the management of these challenging lesions.

Objective: To describe the spectrum of pediatric ovarian pathology, identifying the clinical features and ultrasound characteristics that help in decisions about patient management, and to correlate these with ovarian pathology. Patients and Methods: Retrospective analysis of 134 records of patients admitted with ovarian lesions to Royal Children's Hospital, Melbourne over an 11-year period (1989-99 inclusive). Results: The age of presentation varied widely from 2 days to 19 years with 63.4% being over 12 years of age. Eighty-one patients (60.4%) had physiological or functional ovarian cysts, 52 of which required surgical intervention. Forty-four patients (32.8%) had neoplastic lesions and a palpable abdominal mass was felt in 53.7% of them. Mature cystic teratoma or dermoid cyst, seen in 27 patients, was the commonest neoplasm, and 77.8% of these children were under 12 years. Six children had malignant ovarian neoplasms, of which five were germ cell in origin. Five patients had epithelial or stromal neoplastic lesions. Endocrine manifestations were seen in seven patients and included early or precocious puberty and virilization. Plain trans-abdominal ultrasonography was useful in identifying ovarian lesions in 94 (81.7%) of the 115 patients in whom it was performed, but was not helpful in determining the nature of the lesion. Neoplastic ovarian lesions were commonly greater than 10 cm in diameter Conclusions: Physiological or functional ovarian cysts are the most common ovarian lesions seen in the pediatric age group and malignant neoplasms are rare. A palpable abdominal mass or ovarian lesion >10 cm was significantly associated with the lesion being neoplastic. Lesions

Lymphadenoma of the salivary gland is a rare neoplasm that has not been properly characterized. This study describes the clinicopathological features of three cases.All three patients were males, ranging in age from 13 to 57 years. Two presented with a parotid mass, and one a preauricular mass. The tumours were well circumscribed, comprising anastomosing trabeculae, solid tubules, glands or basaloid islands of epithelium with or without cyst formation, accompanied by a prominent lymphoid stroma lacking sinuses. Large reactive lymphoid follicles were found in two cases. The epithelial cells were bland-looking to mildly atypical. Immunostaining demonstrated dual luminal cell and abluminal basal cell differentiation, with the former being often subtle and highlighted only by immunostaining for epithelium membrane antigen or CAM 5.2, and the latter being highlighted by p63 immunostain.Although there is some variation in the histological pattern from case to case, lymphadenoma is a morphologically recognizable salivary gland adenoma characterized by a dense lymphoid infiltrate. Lack of familiarity with this tumour may lead to misdiagnosis as myoepithelial sialadenitis, lymphoma, metastatic carcinoma in lymph node or lymphoepithelial carcinoma.