98 research outputs found
Activity-guided fractionation and evaluation of potent antioxidants from extracts of angel wings mushroom, pleurotus porrigens (higher basidiomycetes)
Pleurotus porrigens is a well-known edible, wild mushroom enjoyed as a delicacy by aborigines in Sabah and as source of income for the aborigines who collect and sell them at tamu (local market). This study aimed to evaluate the antioxidant activity in vitro and identify potent antioxidative components of aqueous extracts of P. porrigens. The antioxidant activities were evaluated using DPPH radical scavenging ability, ABTS radical cation inhibition activity, ferric reducing/antioxidant power, and total phenolic content. Activity-guided purifications based on DPPH radical scavenging ability resulted in 5 subfractions (SF). The highest DPPH radical scavenging ability was found in SF-III and SF-IV, but all were lower than butylated hydroxyanisole (BHA) and α-tocopherol. Analysis with high-performance liquid chromatography-diode array detectors found presence of ascorbic acid and (+)-catechin in SFs of P. porrigens, as well as some unidentified components that may have contributed to the radical scavenging ability. In conclusion, aqueous extract of P. porrigens possesses promising antioxidant activities, although they are lesser in their partially purified SFs. Nonetheless, P. porrigens could be promoted as an antioxidant-rich food as part of a normal diet that provides antioxidative benefit
Modelling of msmacomponents: Porous pavement with detention system underneath for low traffic roads
This study has been made in order to pursue practices in Water Sensitive Urban Design (WSUD), where stormwater management becomes a mainstream in Malaysia. The main focus of this study is to develop a stormwater conveyance model incorporating porous pavement and on-site detention system at Heights Drive (Stutong), Kuching City, and to investigate its effectiveness. Conventional pavements are impervious and create contaminated runoff. In contrast, combination of porous pavement with storage as WSUD approach allows stormwater to percolate to an underlying detention system where stormwater is both infiltrated to underlying clay soil and discharged with a lower rate to drain beside the road. Nine roads with total surface area of 12,660 m2 are selected and a total of 6 scenarios are modelled and simulated using EPA’s SWMM 5.0. It is found that the peak discharge at outfall from the study area is decreased by 23%, in which 2% of the stormwater is infiltrated to the ground for groundwater recharge
Two closely related 2-(benzofuran-2-yl)-2-oxoethyl benzoates: structural differences and C 14H...O hydrogen-bonded supramolecular assemblies
The compounds 2-(1-benzofuran-2-yl)-2-oxoethyl 2-nitrobenzoate, C17H11NO6 (I), and 2-(1-benzofuran-2-yl)-2-oxoethyl 2-aminobenzoate, C17H13NO4 (II),
were synthesized under mild conditions. Their molecular structures were
characterized by both spectroscopic and single-crystal X-ray diffraction analysis.
The molecular conformations of both title compounds are generally similar.
However, different ortho-substituted moieties at the phenyl ring of the two
compounds cause deviations in the torsion angles between the carbonyl group
and the attached phenyl ring. In compound (I), the ortho-nitrophenyl ring is
twisted away from the adjacent carbonyl group whereas in compound (II), the
ortho-aminophenyl ring is almost co-planar with the carbonyl group. In the
crystal of compound (I), two C 14
The Changeless Core in a Changing Business Environment
Rapid change in business environment poses threat to business survival. It is crucial to examine the core of business sustainability. This paper proposes changeless factors in response to today’s business environment. Specifically, it addresses (1) the people factor (2) the purpose factor and (3) the principle factor as the pillars through which an organization finds its stability in the sea of business change. This paper demonstrates the unchanged factors to ensure business sustainability and to achieve long term objectives. After mapping the conceptual model, the paper devotes particular attention to conceptualizing the changeless cores of business. This research contributes practical insights for managers to further understand the cores of business sustainability. Specifically, it will assist managers to have clear goals in making decisions and managing change to enhance competitiveness in the business environment
Transformer-based out-of-distribution detection for clinically safe segmentation
In a clinical setting it is essential that deployed image processing systems are robust to the full range of inputs they might encounter and, in particular, do not make confidently wrong predictions. The most popular approach to safe processing is to train networks that can provide a measure of their uncertainty, but these tend to fail for inputs that are far outside the training data distribution. Recently, generative modelling approaches have been proposed as an alternative; these can quantify the likelihood of a data sample explicitly, filtering out any out-of-distribution (OOD) samples before further processing is performed. In this work, we focus on image segmentation and evaluate several approaches to network uncertainty in the far-OOD and near-OOD cases for the task of segmenting haemorrhages in head CTs. We find all of these approaches are unsuitable for safe segmentation as they provide confidently wrong predictions when operating OOD. We propose performing full 3D OOD detection using a VQ-GAN to provide a compressed latent representation of the image and a transformer to estimate the data likelihood. Our approach successfully identifies images in both the far- and near-OOD cases. We find a strong relationship between image likelihood and the quality of a model’s segmentation, making this approach viable for filtering images unsuitable for segmentation. To our knowledge, this is the first time transformers have been applied to perform OOD detection on 3D image data.</p
Antiepileptogenesis after Stroke - Trials and Tribulations: Methodological Challenges and Recruitment Results of a Phase II Study with Eslicarbazepine Acetate.
There is currently no evidence to support the use of antiseizure medications to prevent unprovoked seizures following stroke. Experimental animal models suggested a potential antiepileptogenic effect for eslicarbazepine acetate (ESL), and a Phase II, multicentre, randomised, double-blind, placebo-controlled study was designed to test this hypothesis and assess whether ESL treatment for 1 month can prevent unprovoked seizures following stroke. We outline the design and status of this antiepileptogenesis study, and discuss the challenges encountered in its execution to date. Patients at high risk of developing unprovoked seizures after acute intracerebral haemorrhage or acute ischaemic stroke were randomised to receive ESL 800 mg/day or placebo, initiated within 120 hours after primary stroke occurrence. Treatment continued until Day 30, then tapered off. Patients could receive all necessary therapies for stroke treatment according to clinical practice guidelines and standard of care, and are being followed up for 18 months. The primary efficacy endpoint is occurrence of a first unprovoked seizure within 6 months after randomisation ('failure rate'). Secondary efficacy assessments include occurrence of a first unprovoked seizure during 12 months after randomisation and during the entire study; functional outcomes (Barthel Index original 10-item version; National Institutes of Health Stroke Scale); post-stroke depression (Patient Health Questionnaire-9; PHQ-9); and overall survival. Safety assessments include evaluation of treatment-emergent adverse events; laboratory parameters; vital signs; electrocardiogram; suicidal ideation and behaviour (PHQ-9 question 9). The protocol aimed to randomise approximately 200 patients (1:1), recruited from 21 sites in seven European countries and Israel. Despite the challenges encountered, particularly during the COVID-19 pandemic, the study progressed and included a remarkable number of patients, with 129 screened and 125 randomised. Recruitment was stopped after 30 months, the first patient entered in May 2019, and the study is ongoing and following up on patients according to the Clinical Trial Protocol
Latent Transformer Models for out-of-distribution detection
Any clinically-deployed image-processing pipeline must be robust to the full range of inputs it may be presented with. One popular approach to this challenge is to develop predictive models that can provide a measure of their uncertainty. Another approach is to use generative modelling to quantify the likelihood of inputs. Inputs with a low enough likelihood are deemed to be out-of-distribution and are not presented to the downstream predictive model. In this work, we evaluate several approaches to segmentation with uncertainty for the task of segmenting bleeds in 3D CT of the head. We show that these models can fail catastrophically when operating in the far out-of-distribution domain, often providing predictions that are both highly confident and wrong. We propose to instead perform out-of-distribution detection using the Latent Transformer Model: a VQ-GAN is used to provide a highly compressed latent representation of the input volume, and a transformer is then used to estimate the likelihood of this compressed representation of the input. We demonstrate this approach can identify images that are both far- and near- out-of-distribution, as well as provide spatial maps that highlight the regions considered to be out-of-distribution. Furthermore, we find a strong relationship between an image's likelihood and the quality of a model's segmentation on it, demonstrating that this approach is viable for filtering out unsuitable images
An Experimental Field Study of Delayed Density Dependence in Natural Populations of Aedes albopictus
Aedes albopictus, a species known to transmit dengue and chikungunya viruses, is primarily a container-inhabiting mosquito. The potential for pathogen transmission by Ae. albopictus has increased our need to understand its ecology and population dynamics. Two parameters that we know little about are the impact of direct density-dependence and delayed density-dependence in the larval stage. The present study uses a manipulative experimental design, under field conditions, to understand the impact of delayed density dependence in a natural population of Ae. albopictus in Raleigh, North Carolina. Twenty liter buckets, divided in half prior to experimentation, placed in the field accumulated rainwater and detritus, providing oviposition and larval production sites for natural populations of Ae. albopictus. Two treatments, a larvae present and larvae absent treatment, were produced in each bucket. After five weeks all larvae were removed from both treatments and the buckets were covered with fine mesh cloth. Equal numbers of first instars were added to both treatments in every bucket. Pupae were collected daily and adults were frozen as they emerged. We found a significant impact of delayed density-dependence on larval survival, development time and adult body size in containers with high larval densities. Our results indicate that delayed density-dependence will have negative impacts on the mosquito population when larval densities are high enough to deplete accessible nutrients faster than the rate of natural food accumulation
Tire-breeding mosquitoes of public health importance along an urbanisation gradient in Buenos Aires, Argentina
Fouling mechanisms of ultrafiltration membranes fouled with whey model solutions
In this work, three ultrafiltration (UF) membranes with different molecular weight cut-offs (MWCOs) and made of different materials were fouled with several whey model solutions that consisted of bovine serum albumin (BSA) (1% w/w), BSA (1% w/w) and CaCl2 (0.06% w/w in calcium) and whey protein concentrate (WPC) with a total protein content of 45% w/w at three different concentrations (22.2, 33.3 and 44.4 g·L− 1). The influence of MWCO and membrane material on the fouling mechanism dominating the UF process was investigated. Experiments were performed using two flat-sheet organic membranes and a ceramic monotubular membrane whose MWCOs were 5, 30 and 15 kDa, respectively. Hermia's models adapted to crossflow UF, a combined model based on complete blocking and cake formation equations and a resistance-in-series model were fitted to permeate flux decline curves. The results demonstrated that permeate flux decline was accurately predicted by all the models studied. However, the models that fitted the best to permeate flux decline experimental data were the combined model and the resistance-in-series model. Therefore, complete blocking and cake formation were the predominant mechanisms for all the membranes and feed solutions tested.The authors of this work wish to gratefully acknowledge the financial support of the Spanish Ministry of Science and Innovation through the project CTM2010-20186.Corbatón Báguena, MJ.; Alvarez Blanco, S.; Vincent Vela, MC. (2015). Fouling mechanisms of ultrafiltration membranes fouled with whey model solutions. Desalination. 360:87-96. https://doi.org/10.1016/j.desal.2015.01.019S879636
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