2,213 research outputs found

    Study on Corrosion Characteristics of Aluminum Alloy Al3102 in Sulfate-reducing Bacteria Environment and Investigating the Use of Azadirachta indica Leaves Extract in its Control

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    An effort to understand the corrosion characteristics of aluminium Al3102 alloy in a neutral medium in the presence of Desulfovibrio desulfuricans was made. The corrosion rate increased up to tenfold in the bacterial medium in comparison to the control (abiotic) medium. Scanning electron microscopy (SEM) studies showed substantial sulfate-reducing bacteria (SRB) adhesion on the alloy surface and pit formation. Supplementation of 1000 ppm Azadirachta indica leaves extract decreased corrosion by 82%. Sulfide analysis, SEM, and X-ray photoelectron spectroscopy (XPS) studies showed a significant effect of neem leaf extract (NLE) on bacterial metabolic activity and confirmed the adsorption of the inhibitor molecules on Al3102 surface. Electrochemical impedance spectroscopy studies showed that the NLE formed a highly resistive external layer which protected the alloy surface from the corrosive effects. The gas chromatography-mass spectroscopy studies (GC-MS) showed appreciable amount of esters, terpenoids, heterocyclic nitrogen, sulfur compounds, and organic bromine compounds in NLE

    Counterfactual Augmentation for Multimodal Learning Under Presentation Bias

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    In real-world machine learning systems, labels are often derived from user behaviors that the system wishes to encourage. Over time, new models must be trained as new training examples and features become available. However, feedback loops between users and models can bias future user behavior, inducing a presentation bias in the labels that compromises the ability to train new models. In this paper, we propose counterfactual augmentation, a novel causal method for correcting presentation bias using generated counterfactual labels. Our empirical evaluations demonstrate that counterfactual augmentation yields better downstream performance compared to both uncorrected models and existing bias-correction methods. Model analyses further indicate that the generated counterfactuals align closely with true counterfactuals in an oracle setting.Comment: Accepted to Findings of EMNLP 202

    Sequence-based design of a peptide probe for the APC tumor suppressor protein

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    AbstractBackground: Proteins form specific associations, but predictive rules for protein pairing are generally unknown. Here, we describe amino-acid sequence patterns capable of mediating specific pairing of a widespread protein motif: the parallel, dimeric, α-helical coiled coil. The pairing rules were tested by designing a 54-residue peptide (anti-APCp1) that is predicted to dimerize preferentially with a coiled-coil sequence from the adenomatous polyposis coli (APC) tumor suppressor protein.Results: As judged by circular dichroism, ultracentrifugation and native gel electrophoresis, anti-APCp1 formed a specific, helical, dimeric complex with the target APC coiled coil. On western blots of APC fragments expressed in Escherichia coli, the designed peptide detected a pattern of bands identical to the pattern detected by an antibody directed against the APC coiled coil. Peptide-mediated precipitation experiments showed that anti-APCp1 bound and sequestered wild-type and mutant APC proteins in extracts of human colon cancer cell lines. In addition, binding of the designed peptide preserved native APC–β-catenin complexes.Conclusions: These biochemical experiments demonstrate that the anti-APC peptide preferentially forms a heterodimeric coiled coil with mutant and full-length APC proteins. The specificity of the designed peptide is sufficient to support several applications that commonly use antibodies. The observed specificity of anti-APCp1 validates the pairing rules used as the basis for the probe design, and it suggests that residues in the core positions of coiled coils help impart pairing selectivity

    Flying Schedule-Matching Descents to Explore Flight Crews' Perceptions of Their Load and Task Feasibility

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    Multiple studies have investigated the development and use of ground-based (controller) tools to manage and schedule traffic in future terminal airspace. No studies have investigated the impacts that such tools (and concepts) could have on the flight-deck. To begin to redress the balance, an exploratory study investigated the procedures and actions of ten Boeing-747-400 crews as they flew eight continuous descent approaches in the Los Angeles terminal airspace, with the descents being controlled using speed alone. Although the study was exploratory in nature, four variables were manipulated: speed changes, route constraints, clearance phraseology, and winds. Despite flying the same scenarios with the same events and timing, there was at least a 50 second difference in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The primary focus of this paper is the potential impact of ground scheduling tools on the flight crews performance and procedures. Crews reported "moderate to low" workload, on average; however, short periods of intense and high workload were observed. The non-flying pilot often reported a higher level of workload than the flying-pilot, which may be due to their increased interaction with the Flight Management Computer, when using the aircraft automation to assist with managing the descent clearances. It is concluded that ground-side tools and automation may have a larger impact on the current-day flight-deck than was assumed and that studies investigating this impact should continue in parallel with controller support tool development

    Implementing a hybrid cognitive-behavioural therapy for pain-related insomnia in primary care : lessons learnt from a mixed-methods feasibility study

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    Objectives: To test the feasibility of implementing a brief but intensive hybrid cognitive behavioural therapy (Hybrid CBT) for pain-related insomnia. Design: Mixed-methods, with qualitative process evaluation on a two-arm randomised controlled feasibility trial. Setting: Primary care. Participants: Twenty-five adult patients with chronic pain and insomnia. Intervention: Hybrid CBT or self-help control intervention. Primary and secondary outcome measures: Primary outcomes measures were the Insomnia Severity Index and interference scale of the Brief Pain Inventory (BPI). Secondary outcomes measures were the present pain intensity rating from the BPI, Multidimensional Fatigue Inventory, Hospital Anxiety and Depression Scale and EQ-5D-5L. Results: Fourteen participants were randomised to receive Hybrid CBT, 11 to receive the self-help control treatment. Of the 14 in the Hybrid CBT group, 9 (64%) completed all four treatment sessions (4 discontinued due to poor health; 1 due to time constraints). Adherence to the self-help control treatment was not monitored. The total number of participants completing the 12-week and 24-week follow-ups were 12 (6 in each group; Hybrid CBT: 43%; self-help: 55%) and 10 (5 in each group; Hybrid CBT: 36%; self-help: 45%). Based on the data available, candidate outcome measures appeared to be sensitive to changes associated with interventions. Thematic analysis of pre-postintervention interview data revealed satisfaction with treatment content among those who completed the Hybrid CBT, whereas those in the self-help control treatment wanted more contact hours and therapist guidance. Other practical suggestions for improvement included shortening the duration of each treatment session, reducing the amount of assessment paperwork, and minimising the burden of sleep and pain monitoring. Conclusion: Important lessons were learnt with regard to the infrastructure required to achieve better patient adherence and retention. Based on the qualitative feedback provided by a subset of treatment completers, future trials should also consider lowering the intensity of treatment and streamlining the data collection procedure. Trial registration number: ISRCTN17294365

    Flight-Deck Strategies and Outcomes When Flying Schedule-Matching Descents

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    Recent studies at NASA Ames Research Center have investigated the development and use of ground-based (air traffic controller) tools to manage and schedule air traffic in future terminal airspace. An exploratory study was undertaken to investigate the impacts that such tools (and concepts) could have on the flight-deck. Ten Boeing 747-400 crews flew eight optimized profile descents in the Los Angeles terminal airspace, while receiving scripted current day and futuristic speed clearances, to ascertain their ability to fly schedulematching descents without prior training. Although the study was exploratory in nature, four variables were manipulated: route constraints, winds, speed changes, and clearance phraseology. Despite flying the same scenarios with the same events and timing, there were significant differences in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The focus of this paper is the examination of the crews' aircraft management strategies and outcomes. This includes potentially problematic human-automation interaction issues that may negatively impact arrival times, speed and altitude constraint compliance, and energy management efficiency

    Mechanical factors implicated in zirconia implant fracture placed within the anterior region - a systematic review

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    Background: To analyze the fracture resistance of zirconia implants within the anterior region and evaluate whether zirconia–zirconia implants can be a viable alternative to titanium implants. Methods: Four online databases (Cochrane Library, Ovid, PubMed, and Scopus) were searched for the period of January 2011 to July 2021. All studies that analyzed the in vivo clinical outcome of two-piece implants in the anterior region in English language were included. Results: The search strategy identified 242 studies. Of these studies, three studies were included for qualitative synthesis based on the pre-determined eligibility criteria. The results showed that there is significant difference in biological results, fractal behavior and other complications between one-piece and two-piece zirconia implants. Two-piece zirconia implants demonstrated favorable longevity and success rates within anterior maxillary in short-term trials. Conclusions: Although factors involved in fractures have been identified—sandblasting, implant diameter, occlusal load, age and implant coating—there is limited quantitative assessment to gauge the fracture resistance of two-piece zirconia implants. Hence, further research with long-term clinical evidence is required

    Interleukin-6 in obese type II diabetes with hypertension

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    Background: Type II diabetes mellitus (T2DM) and obesity are found to be associated with increased incidence of hypertension, although the mechanisms facilitating hypertension in T2DM or nondiabetic individuals are not clear.Methods: We compared the levels of fasting plasma glucose, HbA1c, lipid subfractions and inflammatory cytokine interleukin 6 (IL-6), being risk factors previously found to be associated with hypertension, in T2DM patients showing increased body weight (obese and overweight with body mass index, BMI ≥25 kg/m2) with hypertension (group A, n=30), or without hypertension (group B, n=30), and in non-obese (BMI <25 kg/m2), normotensive controls (group C, n=40).Results: BMI, HbA1c, fasting plasma glucose, total cholesterol, triglycerides, HDL cholesterol and LDL cholesterol were found to be significantly higher in group A, B Vs C (p <0.05). Also, IL-6 levels were significantly higher both in group A and B compared to group C. The highest level of IL-6 was found in group A, being significantly higher than in group B (A: 14.34 ± 4.98 pg/ml; B: 10.66 ± 1.16 pg/ml; C: 7.41 ± 0.54 pg/ml, A vs. B p<0.001; A, B vs. C p<0.001).Conclusions: Our results have shown that appearance of hypertension in T2DM patients with increased body weight was dependent on rise in inflammatory marker IL-6 cytokine.  
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