A TRANSFER MATRIX APPROACH TO DETERMINE THE LOW FREQUENCY INSERTION LOSS OF ENCLOSURES INCLUDING APPLICATIONS

Partial enclosures are commonly used to reduce machinery noise. However, it is well known in industry that enclosures sometimes amplify the sound at low frequencies due to strong acoustic resonances compromising the performance. These noise issues are preventable if predicted prior to prototyping and production. Though boundary and finite element approaches can be used to accurately predict partial enclosure insertion loss, modifications to the model require time for remeshing and solving. In this work, partial enclosure performance at low frequencies is simulated using a plane wave transfer matrix approach. Models can be constructed and the effect of design modifications can be predicted rapidly. Results are compared to finite element analysis and measurement with good agreement. The approach is then used to design and place resonators into a sample enclosure. Improvements in enclosure performance are predicted using plane wave simulation, compared with acoustic finite element analysis, and then validated via measurement

Astrocytic p75NTR expression provoked by ischemic stroke exacerbates the blood-brain barrier disruption

The disruption of the blood–brain barrier (BBB) plays a critical role in the pathology of ischemic stroke. p75 neurotrophin receptor (p75NTR) contributes to the disruption of the blood-retinal barrier in retinal ischemia. However, whether p75NTR influences the BBB permeability after acute cerebral ischemia remains unknown. The present study investigated the role and underlying mechanism of p75NTR on BBB integrity in an ischemic stroke mouse model, middle cerebral artery occlusion (MCAO). After 24 h of MCAO, astrocytes and endothelial cells in the infarct-affected brain area up-regulated p75NTR. Genetic p75NTR knockdown (p75NTR+/ ) or pharmacological inhibition of p75NTR using LM11A-31, a selective inhibitor of p75NTR, both attenuated brain damage and BBB leakage in MCAO mice. Astrocyte-specific conditional knockdown of p75NTR mediated with an adeno-associated virus significantly ameliorated BBB disruption and brain tissue damage, as well as the neurological functions after stroke. Further molecular biological examinations indicated that astrocytic p75NTR activated NF-κB and HIF-1α signals, which upregulated the expression of MMP-9 and vascular endothelial growth factor (VEGF), subsequently leading to tight junction degradation after ischemia. As a result, increased leukocyte infiltration and microglia activation exacerbated brain injury after stroke. Overall, our results provide novel insight into the role of astrocytic p75NTR in BBB disruption after acute cerebral ischemia. The p75NTR may therefore be a potential therapeutic target for the treatment of ischemic stroke

Contaminated feed-borne Bacillus cereus aggravates respiratory distress post avian influenza virus H9N2 infection by inducing pneumonia

Avian influenza virus subtype H9N2 is identified in chickens with respiratory disease while Bacillus cereus (B. cereus) has been frequently isolated from chicken feed in China. However, the roles of co-infection with these two pathogens remain unclear. In the present study, SPF chicks were intragastrically administered with 108 CFU/mL of B. cereus for 7 days and then inoculated intranasally with 100 EID50 of H9N2 three days later. Alternatively, chickens were initially inoculated with H9N2 and then with B. cereus for one week. Post administration, typical respiratory distress persisted for 5 days in both co-infection groups. Gizzard erosions developed in the groups B. cereus/H9N2 and B. cereus group on 7th day while in group H9N2/B. cereus on 14th day. More importantly, both air-sac lesions and lung damage increased significantly in the co-infection group. Significant inflammatory changes were observed in the B. cereus group from day 7 to day 21. Moreover, higher loads of H9N2 virus were found in the co-infected groups than in the H9N2 group. Newcastle Disease Virus (NDV) specific antibodies were decreased significantly in the H9N2/B. cereus group compared to the B. cereus and the B. cereus/ H9N2 groups. Nonspecific IgA titers were reduced significantly in the B. cereus group and the H9N2/B. cereus group compared to the control group. In addition to this, lower lymphocyte proliferation was found in the con-infection groups and the H9N2 group. Hence, feed-borne B. cereus contamination potentially exacerbates gizzard ulceration and aggravates H9N2-induced respiratory distress by inhibiting antibody-mediated immunity and pathogen clearance. Thus controlling the B. cereus contamination in poultry feed is immediately needed.http://www.nature.com/scientificreportsam2019Paraclinical Science

Automated Cross-prompt Scoring of Essay Traits

The majority of current research in Automated Essay Scoring (AES) focuses on prompt-specific scoring of either the overall quality of an essay or the quality with regards to certain traits. In real-world applications obtaining labelled data for a target essay prompt is often expensive or unfeasible, requiring the AES system to be able to perform well when predicting scores for essays from unseen prompts. As a result, some recent research has been dedicated to cross-prompt AES. However, this line of research has thus far only been concerned with holistic, overall scoring, with no exploration into the scoring of different traits. As users of AES systems often require feedback with regards to different aspects of their writing, trait scoring is a necessary component of an effective AES system. Therefore, to address this need, we introduce a new task named Automated Cross-prompt Scoring of Essay Traits, which requires the model to be trained solely on non-target-prompt essays and to predict the holistic, overall score as well as scores for a number of specific traits for target-prompt essays. This task challenges the model's ability to generalize in order to score essays from a novel domain as well as its ability to represent the quality of essays from multiple different aspects. In addition, we introduce a new, innovative approach which builds on top of a state-of-the-art method for cross-prompt AES. Our method utilizes a trait-attention mechanism and a multi-task architecture that leverages the relationships between each trait to simultaneously predict the overall score and the score of each individual trait. We conduct extensive experiments on the widely used ASAP and ASAP++ datasets and demonstrate that our approach is able to outperform leading prompt-specific trait scoring and cross-prompt AES methods

ALLSH: Active Learning Guided by Local Sensitivity and Hardness

Active learning, which effectively collects informative unlabeled data for annotation, reduces the demand for labeled data. In this work, we propose to retrieve unlabeled samples with a local sensitivity and hardness-aware acquisition function. The proposed method generates data copies through local perturbations and selects data points whose predictive likelihoods diverge the most from their copies. We further empower our acquisition function by injecting the select-worst case perturbation. Our method achieves consistent gains over the commonly used active learning strategies in various classification tasks. Furthermore, we observe consistent improvements over the baselines on the study of prompt selection in prompt-based few-shot learning. These experiments demonstrate that our acquisition guided by local sensitivity and hardness can be effective and beneficial for many NLP tasks.Comment: NAACL 2022 (finding); Our code is publicly available at https://github.com/szhang42/alls

Gastric Ulceration and Immune Suppression in Weaned Piglets Associated with Feed-Borne Bacillus cereus and Aspergillus fumigatus

As a multifactorial cause, gastric ulceration-mediated diarrhea is widely prevalent in the weaned piglets, impairing pig health and economic benefits. With full implementation of antibiotic stewardship programs in China, Bacillus cereus (B. cereus) and Aspergillus fumigatus (A. fumigatus) were identified frequently in porcine feedstuffs and feeds of the animal industry. Association between feed-borne B. cereus and frequent diarrhea remains unclear. In the present study, we conducted a survey of B. cereus and A. fumigatus from feeds and feedstuffs in pig farms during hot season. Interestingly, B. cereus, B. subtilis, B. licheniformis and B. thuringinesis were isolated and identified from piglets’ starter meals to sow feeds, accounting for 56.1%, 23.7%, 13.7% and 6.5%, respectively. Obviously, both B. cereus and B. subtili were dominant contaminants in the survey. In an in vitro study, Deoxynivalenol (DON) contents were determined in a dose-dependent manner post fermentation with B. cereus (405 and DawuC). Subsequently, 36 weaned piglets were randomly assigned to four groups and the piglets simultaneously received the combination of virulent B. cereus (Dawu C) and A. fumigatus while animals were inoculated with B. cereus (Dawu C), A. fumigatus or PBS as the control group. Clinically, piglets developed yellow diarrhea on day 5 and significant reductions of relative body weight were observed in the B. cereus group, and co-infection group. More importantly, IgG titers against Classical swine fever virus (CSFV) and Porcine epidemic diarrhea (PED) were reduced dramatically during 14-day observation in co-infection group, the B. cereus (Dawu C) group or the A. fumigatus group. However, lower Foot and mouth disease (FMD) -specific antibodies were reduced on day 7 compared to those of the control group. Additionally, lower lymphocyte proliferations were found in the B. cereus group and the co-infection group compared to the control group. Postmortem, higher lesions of gastric ulceration were observed in the B. cereus group and the co-infection group from day 7 to day 14 compared with those of the A. fumigatus group and the control group. Compared to the A. fumigatus group, higher DON contents were detected in the stomach inoculated with B. cereus and the co-infection with A. fumigatus. In conclusion, our data support the hypothesis that B. cereus might be associated with severe diarrhea by inducing gastric ulcerations and A. fumigatus might aggravate immune suppression, threating a sustainable swine industry. It is urgently needed to control feed-borne B. cereus contamination