An experimental and analytical study of the mechanism of material modification when a bias is applied between AFM tip and gold and highly oriented pyrolytic graphite

The fabrication of nanostructures is of great importance for the continued development of nanodevices and molecular electronics. While field assisted tip based techniques are proposed to be versatile nanofabrication techniques that can be used for atomic-scale surface modification of wide variety of materials, the mechanism of material transport is not well understood. This research was performed to better understand the mechanisms of surface modification when the voltage bias is applied in ambient conditions; in particular, the conditions that Liu et al.1,2 proposed will cause material transport. We studied the evolution of the current voltage behavior of a doped silicon AFM tip on gold film on mica and highly ordered pyrolytic graphite (HOPG) to understand the impact of current on material modification for negative tip biases up to 10V. The SEM images of tips before and after use were compared to examine the physical changes caused to the tip and x-ray energy dispersive spectroscopy analysis was performed to study the chemical composition of used tips. We monitored modification on substrates and proposed possible mechanisms of material transport. We performed heat transfer analysis of the tip-substrate interface to show that the measured powers for negative tip biases in the range of 6--10 V are sufficient to raise the temperature at the interface to as high as 100--1100 °C which in combination with very high electric field (\u3e 108 Vm-1) is sufficient to cause tip oxidation of bare silicon tip in an ambient environment and can cause diffusion, evaporation or melting of thin coatings from coated silicon tips used by Liu and Miller.1,2

VGGFace2: A dataset for recognising faces across pose and age

In this paper, we introduce a new large-scale face dataset named VGGFace2. The dataset contains 3.31 million images of 9131 subjects, with an average of 362.6 images for each subject. Images are downloaded from Google Image Search and have large variations in pose, age, illumination, ethnicity and profession (e.g. actors, athletes, politicians). The dataset was collected with three goals in mind: (i) to have both a large number of identities and also a large number of images for each identity; (ii) to cover a large range of pose, age and ethnicity; and (iii) to minimize the label noise. We describe how the dataset was collected, in particular the automated and manual filtering stages to ensure a high accuracy for the images of each identity. To assess face recognition performance using the new dataset, we train ResNet-50 (with and without Squeeze-and-Excitation blocks) Convolutional Neural Networks on VGGFace2, on MS- Celeb-1M, and on their union, and show that training on VGGFace2 leads to improved recognition performance over pose and age. Finally, using the models trained on these datasets, we demonstrate state-of-the-art performance on all the IARPA Janus face recognition benchmarks, e.g. IJB-A, IJB-B and IJB-C, exceeding the previous state-of-the-art by a large margin. Datasets and models are publicly available.Comment: This paper has been accepted by IEEE Conference on Automatic Face and Gesture Recognition (F&G), 2018. (Oral

Image Compression System using ANN

The rapid growth of digital imaging applications, including desktop publishing, multimedia, teleconferencing, and high definition television (HDTV) has increased the need for effective and standardized image compression techniques. Among the emerging standards are JPEG, for compression of still images; MPEG, for compression of motion video; and CCITT H.261 (also known as Px64), for compression of video telephony and teleconferencing. All three of these standards employ a basic technique known as the discrete cosine transform (DCT), Developed by Ahmed, Natarajan, and Rao [1974]. Image compression using Discrete Cosine Transform (DCT) is one of the simplest commonly used compression methods. The quality of compressed images, however, is marginally reduced at higher compression ratios due to the lossy nature of DCT compression, thus, the need for finding an optimum DCT compression ratio. An ideal image compression system must yield high quality compressed images with good compression ratio, while maintaining minimum time cost. The neural network associates the image intensity with its compression ratios in search for an optimum ratio

Template Adaptation for Face Verification and Identification

Face recognition performance evaluation has traditionally focused on one-to-one verification, popularized by the Labeled Faces in the Wild dataset for imagery and the YouTubeFaces dataset for videos. In contrast, the newly released IJB-A face recognition dataset unifies evaluation of one-to-many face identification with one-to-one face verification over templates, or sets of imagery and videos for a subject. In this paper, we study the problem of template adaptation, a form of transfer learning to the set of media in a template. Extensive performance evaluations on IJB-A show a surprising result, that perhaps the simplest method of template adaptation, combining deep convolutional network features with template specific linear SVMs, outperforms the state-of-the-art by a wide margin. We study the effects of template size, negative set construction and classifier fusion on performance, then compare template adaptation to convolutional networks with metric learning, 2D and 3D alignment. Our unexpected conclusion is that these other methods, when combined with template adaptation, all achieve nearly the same top performance on IJB-A for template-based face verification and identification

Towards Recommender Systems for Police Photo Lineup

Photo lineups play a significant role in the eyewitness identification process. This method is used to provide evidence in the prosecution and subsequent conviction of suspects. Unfortunately, there are many cases where lineups have led to the conviction of an innocent suspect. One of the key factors affecting the incorrect identification of a suspect is the lack of lineup fairness, i.e. that the suspect differs significantly from all other candidates. Although the process of assembling fair lineup is both highly important and time-consuming, only a handful of tools are available to simplify the task. In this paper, we describe our work towards using recommender systems for the photo lineup assembling task. We propose and evaluate two complementary methods for item-based recommendation: one based on the visual descriptors of the deep neural network, the other based on the content-based attributes of persons. The initial evaluation made by forensic technicians shows that although results favored visual descriptors over attribute-based similarity, both approaches are functional and highly diverse in terms of recommended objects. Thus, future work should involve incorporating both approaches in a single prediction method, preference learning based on the feedback from forensic technicians and recommendation of assembled lineups instead of single candidates

Phaeohyphomycotic cyst

Phaeohyphomycosis is a term used for a rare opportunistic infection caused by a group of dematiaceous fungi which contains melanin in their cell walls. In 1974, the term phaeohyphomycosis was first coined by Ajello for an entity caused by pigmented fungi.1 Four clinical forms of phaeohyphomycosis exist: i) cutaneous, ii) subcutaneous, iii) systemic, and iv) cerebral. Among these, the subcutaneous form (phaeohyphomycotic cyst) is the most common subtype which usually presents as nodular swelling mainly over the distal extremities, which may be misdiagnosed as epidermal inclusion cyst, ganglion or lipoma. These fungi are present in the soil, where they infect mostly farmers and persons working in fields and farms. It was also highlighted that these infections are seen mostly in immunocompromised individuals and are byproducts of antimicrobial, steroid, and immunosuppressive therapy for various illnesses, including cancer, autoimmune diseases, and transplant cases.1 The pigment giving the characteristic brownish-black appearance to the fungi is melanin, which prevents phagocytosis and hence acts as a virulence factor.2 This group has more than 120 species and 70 genera.3 They have a broad spectrum of clinical manifestations, including superficial and deep fungal infections, sinus involvement, and disseminated forms, including lung and brain abscesses. The incidence ranges from 1-3.1 per 100,000 patients.4 The gold standard method for diagnosis is histopathological examination and culture. Fontana-Masson stain is of immense help in identifying these dematiaceous fungi in tissue as it highlights the melanin pigment in the cell walls. Figure 1 refers to a 59-year-old farmer man who presented with nodular swelling over the dorsum of the left hand for the last 9 months. Initially, the swelling was of peanut size, which gradually progressed to the present size of 5x3x2cm. The lesion was painless, well-defined, and freely mobile. The joint was not affected. He is on medication for type II diabetes mellitus and hypertension. He underwent Whipple's surgery for periampullary carcinoma. He was treated for proximal sensory-motor axonal neuropathy and tuberculosis three years back. Because of isoniazid-induced hepatitis, the patient received a modified anti-tuberculous regime for 9 months, after which he developed gastric ulceration with hematemesis and melena. On endoscopic biopsy, he was found to have chronic active gastritis with Helicobacter pylori infection. In addition, the patient had severe iron deficiency and hypoalbuminemia due to malabsorption. After treatment, he completely recovered at the time of hospital discharge. Figure 1 Phaeohyphomycotic cyst. A - A well-encapsulated and unilocular cyst measuring 4.5x2.2x1.8cm in size (scale bar = 2.5cm); The cyst lumen contains homogenous and translucent gelatinous soft material; B - Multinucleated giant cells showing fungal profile with septate, branching and globose swelling (H&E; x200); C - Periodic Acid-Schiff stain showing bright magenta positivity (PAS stain; x200); D - Fontana Masson stain giving brownish black color due to melanin in the fungal cell walls (x200).: Thus, the nodular swelling was wholly excised and sent for histopathological examination. Grossly, a well-encapsulated mass measuring 4.5x2.2x1.8 cm was submitted for histological analysis (Figure 1A). The external aspect appeared intact, yellowish-white, and congested. A unilocular cyst was identified on serial slicing with a capsular thickness of 0.1-0.2cm. The cut surface was soft in consistency with homogenous and gelatinous translucent material within the lumen. On light microscopy, an outer thick fibrous capsule layer was identified. Just beneath this capsular layer was the vascularized granulation tissue, proliferating fibroblasts, numerous multinucleated foreign and Langhan’s giant cells, and variable lymphoplasmacytic cell infiltrate. Also, abundant basophilic mucoid material with a background of many degenerated cells. These giant cells engulfed pigmented fungal profiles that depicted branching, septate and globose swelling (Figure 1B). Periodic Schiff-Acid stain gave bright magenta color to these fungi (Figure 1C), whereas Fontana Masson stain gave brownish black color due to melanin in the fungal cell walls (Figure 1D). Given the morphology, a diagnosis of a phaeohyphomycotic cyst was rendered. On follow-up, the patient is doing well, and has not received any antifungal agent. The leading treatment choice in non-invasive subcutaneous phaeohyphomycosis is local excision

Mucinous tubular and spindle cell carcinoma of the kidney

Mucinous tubular and spindle cell carcinoma (MTSCC) is a unique neoplasm attributing to less than 1% of all renal cell carcinoma (RCC). The median age is 6th decade with a significant female preponderance.1 These tumors classically consist of tightly packed, elongated, and anastomosing tubules which merge with bland spindle cells in a myxoid stroma in variable proportions. Tubules with tufting or small papillae and foci of foamy macrophages may occur. The tumor cells are low-grade and may show clear cytoplasm or oncocytic changes with rare mitosis. Immunohistochemically, PAX8, CK7, AMACR, and CD10 are positive in this tumor.1,2 Though it is a morphological diagnosis, it can be challenging to differentiate from a solid variant of papillary RCC, sarcomatoid RCC, or myoid-predominant angiomyolipoma. Immunohistochemistry may be of little help due to overlapping profiles.3 Copy number analyses can help establish a diagnosis in challenging cases or core biopsies since these are associated with multiple chromosomal losses involving chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22. Novel biomarkers like VSTM2A overexpression are also emerging, which can be detected by RNA in-situ hybridization. Recurrent Hippo pathway aberrations have been defined as the molecular signature of MTSCC with increased nuclear YAP1 protein expression.4 Adverse features such as necrosis, solid growth, single file infiltration, sarcomatoid transformation, lymphovascular invasion, and increased mitoses are indicators of metastatic disease. Although it has indolent behavior, rare cases with classic morphology have been seen to develop metastases.5-6 We describe gross and histopathological findings of mucinous tubular and spindle cell carcinoma in a 65-year-old male patient. He presented with right abdominal pain for one month. The pain was dull and mild to moderate in intensity. On contrast-enhanced ultrasound, a well-defined, smoothly marginated heterogeneous hyperechoic lesion measuring 5.5x6cm was noted at the upper pole of the right kidney. The lesion was hyper enhancing compared to the rest of the renal parenchyma. Based on the radiological findings, possibilities of chromophobe RCC and oncocytoma were considered. The abdominal computed tomography (CT) revealed a hyperdense lesion in the upper pole of the right kidney with a relatively well-defined margin measuring 63x65x69mm with no evidence of significant post-contrast enhancement in the either arterial, venous or delayed phase. The patient underwent a right radical nephrectomy. On gross examination, a well-encapsulated mass was seen wholly occupying the upper pole of the kidney measuring 6.9x6.5x5.5cm. The cut surface was variegated with grey-white, firm areas admixed with mucinous and hemorrhagic foci (Figure 1A). No capsular breach or perinephric fat extension was noted. The renal pelvis, sinus, and renal vessels were free of tumor. Figure 1 A - gross nephrectomy specimen showing a large, well-demarcated tumor involving the upper pole of the kidney measuring 6.9x6.5x5.5cm. The cut surface is variegated and appears grey-white and firm, along with intervening mucinous and hemorrhagic areas (scale bar = 5 cm); B - microscopically, the tumor is well-circumscribed with sharp demarcation from adjacent normal renal parenchyma (H&E; 40x); C - the dominant epithelial component is seen against the background stroma containing significant extracellular mucin (H&E; 100x); D - higher magnification showing tightly packed anastomosing tubules lined by low-grade cuboidal cells with cytoplasmic vacuoles against mucinous background (H&E; 400x).: Microscopically, the tumor was well-demarcated from the adjacent native renal parenchyma (Figure 1B). It was composed of the dominant epithelial element against the background of extracellular mucinous stroma (Figure 1C). The epithelial component contained tightly packed, elongated, tufted, and anastomosing tubules lined by low-grade cuboidal cells and are seen merging with bland spindle cells (Figure 1D). The nuclei display fine vesicular chromatin, inconspicuous nucleoli, and moderate cytoplasm with vacuolations. Mitotic figures are infrequent (<1/10HPF). No necrosis, lymphovascular invasion, or high-grade transformation was found. However, foamy macrophage collections and lymphoid aggregates are admixed. Cholesterol clefts with focal foreign body giant cell response indicated the long-standing nature of the tumor. Based on the gross and microscopy findings, the diagnosis of mucinous tubular and spindle cell carcinoma [(pT1bpNx; American Joint Committee on Cancer (AJCC) staging manual; 8th edition)] was rendered

Renal lymphangiectasia

Renal lymphangiectasia (RL), also known as renal lymphangiomatosis, is a rare benign condition characterized by ectasia of peripelvic, perirenal and intrarenal lymphatic vessels. It accounts for approximately 1% of all lymphangiomas.1 The pathophysiology of renal lymphangiectasia remains unclear. However, it is hypothesized that the failure of draining into the larger retroperitoneal lymphatic channels causes abnormal cystic dilatation of the peripelvic, perirenal and intrarenal lymphatic ducts.2 RL can manifest at any age, with males and females equally affected. Lymphangiectasia can involve both kidneys, albeit unilateral involvement is common. Patients may be asymptomatic or present with flank pain, abdominal distention, lower limb oedema, hematuria and hypertension. Extreme presentation such as renal failure has also been documented. Due to the classical imaging features, computed tomography (CT) scan becomes the best diagnostic modality for the diagnosis, which can be confirmed by aspiration of chylous fluid.3 In the pediatric patient, the differential diagnosis includes cystic diseases of the kidney, nephroblastomatosis, and hydronephrosis with perinephric urinoma. Depending on the presentation, the management varies, including conservative, percutaneous aspiration, marsupialization, and nephrectomy.4 We describe gross and microscopic features of renal lymphangiectasia in a 4-year-old male child who presented with gradually progressive abdominal distension for one month with accompanying vague flank pain and fatigue. No hematuria or bladder bowel complaints were noted. Family and perinatal history were not significant. An ill-defined large mass of approximately 20x10cm occupying the left flank and hypochondrium was palpable on bimanual palpation. The renal function test was within normal limits for this age. Ultrasonography (USG) abdomen revealed bilateral multi-loculated, anechoic, cystic lesions in the perirenal and parapelvic region. Raised cortical echoes indicated the loss of corticomedullary distinction. CT scan revealed bilateral non-enhancing multiloculated cystic collection in the perirenal and parapelvic locations. Exploratory laparotomy showed a well-defined thick-walled sac of 20x15cm encasing the left kidney. Intraoperatively, the left kidney was hard to feel, and the architecture was distorted. A Left nephroureterectomy was done and submitted for histopathological evaluation. The kidney with perinephric fat measures 15x9x5.5cm, and the ureter was 5cm in length. The perinephric fat showed multiple collapsed cysts that enclosed the whole kidney ranging in size from 4 to 8cm in the largest dimension. The cut surface of the kidney exhibited well-demarcated multiloculated cysts in the cortex and medulla. The cysts are of variable size measuring 0.5 to 4cm in maximum dimension and shows thickness of 0.2cm and intervening thin septa (Figure 1A). The luminal aspect appeared smooth, contained brownish serous fluid, and did not show any papillary excrescences or growth. The adjacent spared kidney showed indistinct cortico-medullary junction and focal thinning of the cortex (0.3 to 0.4cm). Microscopically, numerous and variably sized cystic spaces were present in the cortex, medulla, pelvis, and perinephric fat (Figure 1B). Glomeruli and tubules in the intervening renal parenchyma showed no abnormal pathology on microscopy; however, the interstitium appears oedematous containing dilated lymphatic channels (Figure 1C). Cystic spaces were lined by a discontinuous layer of flat endothelial cells as highlighted by D2-40 (Figure 1D), CD31, and CD34 immunostains. Neuromatoid hyperplasia was seen in the sections from renal pelvis. Following clinical-radio-pathological correlation, a diagnosis of renal lymphangiectasia was offered. The patient was on close imaging follow-up to keep track of the right kidney

Design of Blind Assistance System Using Refreshable Braille Display

In this paper, we demonstrate that Braille embosser is a type of device which is very useful for the initial stage Braille language learner. Here the input is provided with the help of serial port by mobile through Bluetooth module. This input is in the form of alphabetical form so the input is converted into Braille language which is displayed with the help of actuators. Blind assistance system also allows visually impaired people to do common tasks such as reading in Braille and reading documents. It is a portable device, they can carry wherever they want so that they could get information of place they are visiting with ease. As this device detect the obstacles and also determine at what distance obstacle is person can safely use this device for indoor purpose

Adult diffuse hepatic hemangiomatosis

Diffuse hepatic hemangiomatosis (DHH) is an uncommon vascular lesion, though hemangiomas are the commonest benign tumors of the liver. The etiology is largely unknown to date; however, its association with giant cavernous hemangiomas (GCH) has been reported in the literature. We present herein, the case of a 37-year-old hypothyroid woman with abdominal fullness for 2 months. The contrast-enhanced computed tomography revealed multiple wellencapsulated lesions involving the liver lobes and was diagnosed as giant cavernous hemangiomas. Most of them, except the deep-seated ones, were enucleated. Histopathological examination highlighted the presence of GCH with irregular margin, replacement of hepatic parenchyma, and presence of multiple micro-hemangiomas suggesting the possibility of DHH further substantiated by retrospective radiological assessment. No extrahepatic vascular lesion was noted, and the post-operative recovery and follow-up were uneventful. Adult DHH is an uncommon entity. The diagnosis of DHH and its distinction from GCH are important from the management and prognostic point of view as recurrence, extrahepatic manifestations, features of consumption coagulopathy, and death from the complications are not uncommon