Damage detection based on output-only measurements using cepstrum analysis and a baseline-free frequency response function curvature method

Low-severity multiple damage detection relies on sensing minute deviations in the vibrational or dynamical characteristics of the structure. The problem becomes complicated when the reference vibrational profile of the healthy structure and corresponding input excitation, is unavailable as frequently experienced in real-life scenarios. Detection methods that require neither undamaged vibrational profile (baseline-free) nor excitation information (output-only) constitute state-of-art in structural health monitoring. Unfortunately, their efficacy is ultimately limited by non-ideal input excitation masking crucial attributes of system response such as resonant frequency peaks beyond first (few) natural frequency(ies) which can better resolve the issue of multiple damage detection. This study presents an improved frequency response function curvature method which is both baseline-free and output-only. It employs the cepstrum technique to eliminate [Formula: see text] decay of higher resonance peaks caused by the temporal spread of real impulse excitation. Long-pass liftering screens out the bulk of low-frequency sensor noise along with the excitation. With more visible resonant peaks, the cepstrum purified frequency response functions (regenerated frequency response functions) register finer deviation from an estimated baseline frequency response function and yield an accurate damage index profile. The simulation and experimental results on the beam show that the proposed method can successfully locate multiple damages of severity as low as 5%.

Modulation of sugar feeding behavior by Gymnema sylvestre in Drosophila melanogaster

Introduction: Sugar is the main source of energy for nearly all animals. However, consumption of a high amount of sugars can lead to many metabolic disorders hence, balancing calorie intake in the form of sugar is required. Various herbs are in use to control body weight, cure diabetes and control elevated blood sugar levels. One such herb is Gymnema sylvestre commonly called Gurmar (destroyer of sugar). Gurmar selectively inhibits sugar sensation by mechanisms that are still elusive. Objectives: The primary objective of this study is to understand the effect of gurmar on sweet taste feeding behaviour in insects using the invertebrate model system Drosophila melanogaster. Methods: For this study, we used feeding assays, spectrophotometry and Proboscis Extension Reflex (PER) assay to determine how flies detect gurmar. Additionally, life span analysis, egg-laying behaviour and developmental profiles were used to probe the role of gurmar on the overall health of the flies. During the whole study, we used only the raw powdered form of gurmar (dried leaves) to examine its effect on sweet taste feeding behaviour. Results: Our data demonstrate that whole gurmar in a raw powdered form is aversive to flies and inhibits sugar evoked PER and feeding responses. Also, we observed it takes at least 24 h of starvation time to reduce the consumption of sugar in flies pre-fed on gurmar. Flies lay a fewer number of eggs on gurmar media and show developmental defects. Our data suggest that flies detect gurmar using both taste and olfactory cues. Conclusion: Understanding how gurmar reshapes taste curves to promote reduced consumption of sugars in flies will open up avenues to help people with health issues related to high sugar consumption, but our data also highlights that its consumption should be carefully considered since gurmar is aversive to flies and has detrimental effects on development.

Premature rejection in science: The case of the Younger Dryas Impact Hypothesis

The progress of science has sometimes been unjustifiably delayed by the premature rejection of a hypothesis for which substantial evidence existed and which later achieved consensus. Continental drift, meteorite impact cratering, and anthropogenic global warming are examples from the first half of the twentieth century. This article presents evidence that the Younger Dryas Impact Hypothesis (YDIH) is a twenty-first century case. The hypothesis proposes that the airburst or impact of a comet ∼12,850 years ago caused the ensuing ∼1200-year-long Younger Dryas (YD) cool period and contributed to the extinction of the Pleistocene megafauna in the Western Hemisphere and the disappearance of the Clovis Paleo-Indian culture. Soon after publication, a few scientists reported that they were unable to replicate the critical evidence and the scientific community at large came to reject the hypothesis. By today, however, many independent studies have reproduced that evidence at dozens of YD sites. This article examines why scientists so readily accepted the early false claims of irreproducibility and what lessons the premature rejection of the YDIH holds for science.

Numerical analysis and optimization of key parts in the stirred tank based on solid-liquid flow field

In order to further improve the mixing performance of the mixing device, the structure of the agitator was optimized, and the effects of the diameter and pitch of the agitator on the solid-liquid suspension characteristics were analyzed by single factor method. Multiple reference frame (MRF), computational fluid dynamics, Euler multiphase flow model and standard K- ε turbulence model were used to investigate the effect of the height from the bottom of the agitator on the suspension characteristics of particles in the agitator was studied. The results show that reducing the height from the bottom of the agitator can promote the suspension of particles at the bottom of the tank, but too low height from the bottom will easily produce mixing dead zone at the bottom of the tank, and cause the accumulation of particles. Reducing the height of the agitator from the bottom will enlarge the clear liquid area of the flow field, cause uneven particle distribution and increase the stirring torque. With the increase of agitator diameter, the critical suspension speed of the flow field decrease, but the stirring power required by the flow field increase. Increasing the blade spacing in a certain range can promote the suspension of particles and make the distribution of particles in the flow field more uniform. Therefore, the mixing power and the uniformity of particle concentration distribution need to be considered together in order to make the mixing device more efficient and energy-saving.

Roles matter: Graduate student perceptions of active learning in the STEM courses they take and those they teach

Despite many calls to reform undergraduate science, technology, engineering, and math (STEM) education to incorporate active learning into classes, there has been little attention paid to graduate level classrooms or courses taught by graduate students. Here, we set out to understand if and how STEM graduate students’ perceptions of active learning change in the classes they take versus those they teach. We found that graduate students had taken relatively few graduate level classes using active learning and they felt that more time should be devoted to active learning in the courses they were taking. Teaching assistants felt that they were devoting the right amount of class time to active learning in the classes they taught. Graduate students also felt that they were using teaching methods in the classes they taught that were different from those they thought should be used when teaching undergraduates and were different from how they preferred to learn when taking classes.

Chemotherapy in combination with pembrolizumab and antiangiogenesis in young patients with advanced primary pulmonary mucinous adenocarcinoma: Two case reports

Primary pulmonary mucinous adenocarcinoma is an unusual histological type of non-small cell lung cancer and has a rare prevalence at a young age. There is no standard first-line therapy for advanced primary pulmonary mucinous adenocarcinoma in children and young adults—this study reports two rare cases of primary pulmonary mucinous adenocarcinoma with wild-type anaplastic lymphoma kinase and epidermal growth factor receptor ( EGFR) genes. One is a 13-year-old boy ( Case#1 ), and another is a 27-year-old male ( Case#2). Both two cases were treated with antibiotics for suspected pulmonary infection. In our hospital, they were diagnosed with advanced primary pulmonary mucinous adenocarcinoma, the Eastern Cooperative Oncology Group (ECGO) performance status was three scores. We chose pembrolizumab and chemotherapy plus angiogenesis inhibitors for Case#1 and Case#2. The two patients' symptoms improved and presented with a partial response according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria，the scores of ECOG performance status were two for Case#1 and one for Case#2. This study illustrates a promising outcome for advanced primary pulmonary mucinous adenocarcinoma with immunotherapy and chemotherapy plus angiogenesis inhibitors at a young age.

Observer’s Assessment of Alertness/Sedation-based titration reduces propofol consumption and incidence of hypotension during general anesthesia induction: A randomized controlled trial

Administration of a single propofol bolus dose for anesthesia induction causes hypotension. We included 160 patients (74 males and 86 females; mean age, 42.4 ± 10.7 [range: 18–60] years) with the American Society of Anesthesiologists status I–II undergoing elective surgery under general anesthesia. Using simple randomization, the patients were divided into a conventional group ( n = 80; received 2 mg/kg propofol at a rate of 250 mg/min) and titrated group ( n = 80; received propofol at a rate of 1 mg/kg/min until the Observer's Assessment of Alertness/Sedation scale score reached 1 point). Fentanyl (4 µg/kg) and cisatracurium (0.2 mg/kg) were administered, as appropriate. Systolic blood pressure, diastolic blood pressure, mean blood pressure, and heart rate were recorded at different time points. Propofol consumption, hypotension, and other adverse events were recorded. All the patients were intubated without awareness. Compared with the conventional group, the titrated group showed more stable blood pressure ( p < 0.05), as well as a lower decrease in systolic blood pressure, mean blood pressure at 1 and 3 min, and diastolic blood pressure at 1 min after propofol administration ( p < 0.01). Moreover, compared with the conventional group, the titrated group showed a lower post-intubation hypotension incidence (9 vs. 19 cases; p = 0.04), as well as lower total propofol dosage and propofol dose per kilogram of body weight (93.57 ± 14.40 mg vs. 116.80 ± 22.37 mg and 1.73 ± 0.27 mg/kg vs. 2.02 ± 0.08 mg/kg, respectively, p < 0.01). Compared with conventional propofol usage, titrated propofol administration can reduce the incidence of hypotension and propofol consumption during anesthesia induction.

Genome sequence of Dichelobacter nodosus JKS-07B isolate from J&K, India associated with virulent footrot of sheep

Introduction: Virulent footrot of sheep caused by Dichelobacter nodosus is associated with tremendous economic losses due to recurrent treatment costs and increased culling rates. This organism being a fastidious anaerobe is difficult to isolate on ordinary media that does not support its growth. The D. nodosus serogroup B isolate described in the present study has been used in the preparation of the whole-cell killed vaccine against footrot in India. D. nodosus serogroup B is the predominant serogroup involved in virulent footrot (lesion score 4) in India as well as in many sheep-rearing countries of the globe. Methods: Genomic DNA was extracted using wizard Genomic DNA purification kit. The whole genome of the D. nodosus strain B was sequenced using an Illumina HiSeq 2500 platform and annotated according to functional gene categories. Annotations were performed using in-house developed Perl scripts using Nr/Nt database, uniprot, Pfam, KEGG, Panther DB, and GO database. Result: The assembled genome size is 1.311,533 Mb and GC content is 44.38. A total of 1215 protein-coding genes, 44tRNA and 7 rRNA were identified. The genome shows 98.63% sequence homology with the reference genome. However, 21 new genes have been identified in this genome. The information will provide insights into the various genes and regulators necessary for D. nodosus growth and survival. Discussion: The genome information of this serogroup B of D. nodosus isolate involved in 85–90% cases of virulent footrot of sheep in India provides further insights for improvement of the killed vaccine (B serogroup) developed recently in India. For the development of an efficacious vaccine against virulent footrot, it is essential to know the serological diversity as well as the virulent status of the strains of the D. nodosus. This serogroup isolate is a potential vaccine candidate to mitigate ovine footrot in India as the majority of virulent footrot cases belong to serogroup B of D. nodosus.

Analysis of research on metabolic syndrome in cancer survivors using topic modeling and social network analysis

This study aimed to identify the relationships between the keywords of research on metabolic syndrome in cancer survivors and the entire knowledge research structure, through topic extraction from a macro perspective. From six electronic databases, 918 studies published between 1996 and 2019 were identified and reviewed, and 365 were included. Keyword network analysis and topic modeling were applied to examine the studies. In keyword network analysis, “obesity,” “treatment,” “breast cancer,” “body mass index,” and “prostate cancer” were the major keywords, whereas “obesity” and “breast” were the dominant keywords and ranked high in frequency, degree centrality, and betweenness centrality. In topic modeling, five clustered topics emerged, namely metabolic syndrome component, post CTX(chemotherapy) sequence, prostate-specific antigen-sensitive plot, lifestyle formation, and insulin fluctuation. Topic 2, post CTX sequence, showed the highest salience in earlier studies, but this has decreased over time, and the themes of the studies have also broadened. This study may provide critical basic data for determining the changing trends of research on metabolic syndrome in cancer survivors and for predicting the direction of future research through the visualization of the effects and interactions between the major keywords in research on metabolic syndrome in cancer survivors.