Variational Metric Scaling for Metric-Based Meta-Learning

Metric-based meta-learning has attracted a lot of attention due to its effectiveness and efficiency in few-shot learning. Recent studies show that metric scaling plays a crucial role in the performance of metric-based meta-learning algorithms. However, there still lacks a principled method for learning the metric scaling parameter automatically. In this paper, we recast metric-based meta-learning from a Bayesian perspective and develop a variational metric scaling framework for learning a proper metric scaling parameter. Firstly, we propose a stochastic variational method to learn a single global scaling parameter. To better fit the embedding space to a given data distribution, we extend our method to learn a dimensional scaling vector to transform the embedding space. Furthermore, to learn task-specific embeddings, we generate task-dependent dimensional scaling vectors with amortized variational inference. Our method is end-to-end without any pre-training and can be used as a simple plug-and-play module for existing metric-based meta-algorithms. Experiments on mini-ImageNet show that our methods can be used to consistently improve the performance of existing metric-based meta-algorithms including prototypical networks and TADAM. The source code can be downloaded from https://github.com/jiaxinchen666/variational-scaling.Comment: AAAI202

Portal Vein Gas in a Diabetic Patient with Gas-forming Pararenal Abscess

The incidence of portal vein gas (PVG), which used to be an ominous sign of intestinal sepsis, has increased with progressive improvements in imaging modalities. Therefore, the clinical significance of PVG has changed. Emphysematous pyelonephritis (EPN) is a rare, potentially life-threatening and gas-forming infection of the renal parenchyma and/or its surroundings. Gas-forming pararenal abscess presenting with PVG is even rarer. We hereby present the case of a diabetic female with poor glycemic control, who was diagnosed to have EPN and PVG concurrently by computed tomography. She underwent percutaneous catheter drainage (PCD) of the pyelonephritis. Both cultures of blood and pus grew Klebsiella pneumoniae. Her subsequent clinical course was uneventful. In summary, EPN is a rare but potentially fatal urinary tract infection in diabetic patients, and finding PVG on computed tomography can aid in diagnosis. Conservative treatment with intravenous antibiotics and PCD of pus may be adequate for the patient with EPN. However, nephrectomy may be necessary if the patient deteriorates and PCD fails to contain the infection

Cerebral hemorrhagic infarction following cranioplasty in a shunted patient with tension pneumocephalus resulting from depressed skull and craniodural defect

SummaryA 34-year-old female sustained a severe traumatic brain injury that was treated with decompressive craniectomy and subsequent cranioplasty, then with ventriculoperitoneal shunt about 10 years previously. However, the skull flap was found to be depressed ever since. She was admitted to our hospital for a headache and left hemiparesis with sudden onset. The computed tomography scan displayed tension pneumocephalus in the right frontoparietal region. First, she underwent emergency burr hole drainage and placement of a subdural drain with external ventricular drainage tube. Then her symptoms improved considerably. Unfortunately, 6 months later she was admitted again to our hospital because of headache and left hemiparesis with sudden onset, and the brain computed tomography showed tension pneumocephalus in the right frontoparietal region. She underwent craniectomy to remove the previous depressed skull and simultaneous cranioplasty with Ti-Mesh. On the day of her operation, generalized seizure occurred and her consciousness deteriorated. The magnetic resonance imaging showed hemorrhagic infarction on both sides of the thalamus and the right parieto-occipital region. We think it probable that a sudden increase of cerebral blood flow in the cerebral hemisphere where the cranioplasty had been performed caused reperfusion injury and resulted in hemorrhagic infarction

Clinical Impacts of Delayed Diagnosis of Hirschsprung’s Disease in Newborn Infants

BackgroundAsian infants are at a higher risk of having Hirschsprung’s disease (HD). Although HD is surgically correctable, serious and even lethal complications such as Hirschsprung’s-associated enterocolitis (HAEC) can still occur. The aim of this study was to investigate the risk factors of HAEC, and the clinical impacts of delayed diagnosis of HD in newborn infants.Patients and methodsBy review of medical charts in a medical center in Taiwan, 51 cases of neonates with HD between 2002 and 2009 were collected. Patients were divided into two groups based on the time of initial diagnosis: Group I, diagnosis made within 1 week after birth, and Group II after 1 week. Clinical features including demographic distribution, presenting features of HD, short-term and long-term complications related to HD were compared between the two groups of patients.ResultsThere were 25 patients in Group I and 19 in Group II. Group II patients had more severe clinical signs and symptoms of HAEC than Group I patients. The incidence of preoperative HAEC was 12% in Group I and 63% in Group II (adjusted odds ratio = 12.81, confidence interval = 2.60–62.97). Patients with preoperative HAEC were more likely to develop adhesive bowel obstruction after operation (33% vs. 3%, p = 0.013) and failure to thrive (33% vs. 3%, p = 0.013). Also, patients with long-segment or total colonic aganglionosis were at risk of developing both postoperative HAEC (85% vs. 29%, p = 0.001) and failure to thrive (39% vs. 3%, p = 0.002).ConclusionIn our study, we found that delayed diagnosis of HD beyond 1 week after birth significantly increases the risk of serious complications in neonatal patients. Patients with long-segment or total colonic aganglionosis have higher risk of postoperative HAEC and failure to thrive. Patients with preoperative HAEC are more likely to have adhesive bowel obstruction and failure to thrive

Power-efficient memory bus encoding using stride-based stream reconstruction

With the rapid increase in the complexity of chips and the popularity of portable devices, the performance demand is not any more the only important constraint in the embedded system. In stead, energy consumption has become one of the main design issues for contemporary embedded systems, especially for I/O interface due to the high capacitance of bus transition. In this paper, we propose a bus encoding scheme, which may reduce transitions by reconstructing active address streams with variable cached strides. The key idea is to obtain the variable strides for dierent sets of active addressing streams such that the decoder reconstructs these interlaced streams with these strides. Instead of sending the full address, the encoder may only send partial ad- dress or stride by using either one-hot or binary-inversion encoding. To exploit the locality and dynamically adjust the value of stride of active address streams, we partially compare the previous addresses of existing streams with the current address. Hence, the data transmitted on the bus can be minimally encoded. Experiments with several MediaBench benchmarks show that the scheme can achieve an average of 60% reduction in bus switching activity.Facultad de Informátic

Magnetically Directed Targeting Aggregation of Radiolabelled Ferrite Nanoparticles

Ferrite magnetic nanoparticles (Fe3O4 or iron (II,III) oxide; 15–25 nm of diameter) were developed. These magnetic nanoparticles are a potential vehicle for magnetically induced target aggregation in living animals. In this preliminary study, the radiochemical purity for the radiolabeled magnetic nanoparticles was examined, and the possibility of the magnetically induced targeting of the radio-nanoparticles was evaluated. Our results showed that radiolabeled ferrite nanoparticles can be used as magnetic targeting agents with high labeling efficiency and stability. These particles can be distributed within living animals via intravenous injection, and the biodistribution of the particles can be potentially controlled by external magnetism. These evaluations will be the groundwork for the future development of delivery techniques for radiopharmaceuticals through external magnetic control

Is acupuncture effective in controlling gagging when taking an alginate impressions?

Our community health project aimed to (1) identify the prevalence of gagging among patients attending the Prince Philip Dental Hospital; and to identify socio-demographic variations in reported gagging experiences; and (2) perform a pilot study to evaluate the effectiveness of acupuncture in the control of gagging in the dental setting. Methods: A survey on reported gagging experiences was conducted among patients attending our hospital involving a convenience sample of 225 patients. Participants who reported to previously gag in the dental setting were invited to participate in a pilot study to evaluate the effectiveness of acupuncture in controlling gagging when taking an upper alginate impression. Participants were randomized to receive acupuncture stimulation at a site reported to be effective in the control of gagging on the lower lip (point CV 24) or at a sham site on the upper lip (point GV 26) on their first visit and at their second visit to receive the alternative acupuncture stimulation. Results: The response rate to the survey was 81.3% (183/225). Approximately a third (58/183) reported to have experienced gagging in the dental setting and most frequently encountered this when having a dental impression (among approximately a quarter of participants - 44/183). Half (95/183) reported gagging while performing oral self-care. Four in ten participants (73/183) reported some stress visiting the dentist related to gagging. Sociodemographic variations in reported gagging experiences were evident with respect to age, gender and education level. The response rate to the pilot study was 92.3% (36/39). There was no significant difference in the prevalence of gagging when acupuncture was applied to the test site compared to when acupuncture was applied to the sham site on dental examination (p>0.05) or when taking an upper alginate impression (p>0.05). Conclusions: Gagging in a relative common experience reported by patients attending our hospital – in daily life, in the dental setting and in performing oral self-care. Socio-demographic variations in the prevalence of gagging were apparent. The pilot study does not support the use of acupuncture in controlling gagging in the dental setting.published_or_final_versio

Enhanced Antifungal Bioactivity of Coptis Rhizome Prepared by Ultrafining Technology

The aim of this study was to identify and quantify the bioactive constituents in the methanol extracts of Coptis Rhizome prepared by ultrafining technology. The indicator compound was identified by spectroscopic method and its purity was determined by HPLC. Moreover, the crude extracts and indicator compound were examined for their ability to inhibit the growth of Rhizoctonia solani Kühn AG-4 on potato dextrose agar plates. The indicator compound is a potential candidate as a new plant derived pesticide to control Rhizoctonia damping-off in vegetable seedlings. In addition, the extracts of Coptis Rhizome prepared by ultrafining technology displayed higher contents of indicator compound; they not only improve their bioactivity but also reduce the amount of the pharmaceuticals required and, thereby, decrease the environmental degradation associated with the harvesting of the raw products