bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of the subtypes of gastric cancer based on DNA methylation and the prediction of prognosis
Authors: Li Tengda , Chen Xin , Gu Mingli , Deng Anmei , Qian Cheng
Published: October 2020

Background

Gastric cancer (GC) is a digestive system cancer with a high mortality rate globally. Previous experiences and studies have provided clinicians with ample evidence to diagnose and treat patients with reasonable therapeutic options. However, there remains a need for sensitive biomarkers that can provide clues for early diagnosis and prognosis assessment.

Results

We found 610 independent prognosis-related 5′-cytosine-phosphate-guanine-3′ (CpG) sites (P < 0.05) among 21,121 sites in the training samples. We divided the GC samples into seven clusters based on the selected 610 sites. Cluster 6 had relatively higher methylation levels and high survival rates than the other six clusters. A prognostic risk model was constructed using the significantly altered CpG sites in cluster 6 (P < 0.05). This model could distinguish high-risk GC patients from low-risk groups efficiently with the area under the receiver operating characteristic curve of 0.92. Risk assessment showed that the high-risk patients had poorer prognosis than the low-risk patients. The methylation levels of the selected sites in the established model decreased as the risk scores increased. This model had been validated in testing group and its effectiveness was confirmed. Corresponding genes of the independent prognosis-associated CpGs were identified, they were enriched in several pathways such as pathways in cancer and gastric cancer. Among all of the genes, the transcript level of transforming growth factor β2 (TGFβ2) was changed in different tumor stages, T categories, grades, and patients’ survival states, and up-regulated in patients with GC compared with the normal. It was included in the pathways as pathways in cancer, hepatocellular carcinoma or gastric cancer. The methylation site located on the promoter of TGFβ2 was cg11976166.

Conclusions

This is the first study to separate GC into different molecular subtypes based on the CpG sites using a large number of samples. We constructed an effective prognosis risk model that can identify high-risk GC patients. The key CpGs sites or their corresponding genes such as TGFβ2 identified in this research can provide new clues that will enable gastroenterologists to make diagnosis or personalized prognosis assessments and better understand this disease.
Research on aircraft route planning optimization problem with multi-constraints and dual-targets
Authors: Zhang Qianyu , Ding Xianfeng , Zhou Jingyu , Nie Yi
Published: October 2020

As the core technology in the field of aircraft, the route planning has attracted much attention. However, due to the complexity of the structure and performance constraints of the aircraft, the route planning algorithm does not have well universality, so it cannot be used in a complex environment. In the paper, a multi-constraints and dual-targets aircraft route planning model was established for the real-time requirements of space flight, the dynamic changes of flight environment with time, the accuracy requirements of positioning errors in the safety area, and the minimum turning radius constraints. Based on the directed graph and dynamic programming ideas, the model simulation and model validation were carried out with the data of F question in the “16th Graduate Mathematical Modeling Contest”. The results showed that the optimal path length obtained in data set 1 was 124.61 km, the number of corrections was 11 times, the solution time was 2.3768 seconds, the optimal path length obtained in data set 2 was 110.00 km, and the number of corrections was 12 times. The solution time was 0.0168 seconds. Multi-constraints and dual-targets aircraft route planning model can plan the flight path of the aircraft intuitively and timely, which confirmed the effectiveness of the model.
Pseudomonas species isolated via high-throughput screening significantly protect cotton plants against verticillium wilt
Authors: Tao Xiaoyuan , Zhang Hailin , Gao Mengtao , Li Menglin , Zhao Ting , Guan Xueying
Published: October 2020

Verticillium wilt (VW) caused by Verticillium dahliae is a devastating soil-borne disease that causes severe yield losses in cotton and other major crops worldwide. Here we conducted a high-throughput screening of isolates recovered from 886 plant rhizosphere samples taken from the three main cotton-producing areas of China. Fifteen isolates distributed in different genera of bacteria that showed inhibitory activity against V. dahliae were screened out. Of these, two Pseudomonas strains, P. protegens XY2F4 and P. donghuensis 22G5, showed significant inhibitory action against V. dahliae. Additional comparative genomic analyses and phenotypical assays confirmed that P. protegens XY2F4 and P. donghuensis 22G5 were the strains most efficient at protecting cotton plants against VW due to specific biological control products they produced. Importantly, we identified a significant efficacy of the natural tropolone compound 7-hydroxytropolone (7-HT) against VW. By phenotypical assay using the wild-type 22G5 and its mutant strain in 7-HT production, we revealed that the 7-HT produced by P. donghuensis is the major substance protecting cotton against VW. This study reveals that Pseudomonas specifically has gene clusters that allow the production of effective antipathogenic metabolites that can now be used as new agents in the biocontrol of VW.
Significant transcriptomic changes are associated with differentiation of bone marrow-derived mesenchymal stem cells into neural progenitor-like cells in the presence of bFGF and EGF
Authors: Khan Amir Ali , Huat Tee Jong , Al Mutery Abdullah , El-Serafi Ahmed Taher , Kacem Hassen Hadj , Abdallah Sallam Hasan , Reza Muhammed Faruque , Abdullah Jafri Malin , Jaafar Hasnan
Published: October 2020

Introduction

Mesenchymal stem cells (MSCs) isolated from bone marrow have different developmental origins, including neural crest. MSCs can differentiate into neural progenitor-like cells (NPCs) under the influence of bFGF and EGF. NPCs can terminally differentiate into neurons that express beta-III-tubulin and elicit action potential. The main aim of the study was to identify key genetic markers involved in differentiation of MSCs into NPCs through transcriptomic analysis.

Method

Total RNA was isolated from MSCs and MSCs-derived NPCs followed by cDNA library construction for transcriptomic analysis. Sample libraries that passed the quality and quantity assessments were subjected to high throughput mRNA sequencing using NextSeq®500. Differential gene expression analysis was performed using the DESeq2 R package with MSC samples being a reference group. The expression of eight differentially regulated genes was counter validated using real-time PCR.

Results

In total, of the 3,252 differentially regulated genes between MSCs and NPCs with two or more folds, 1,771 were upregulated genes, whereas 1,481 were downregulated in NPCs. Amongst these differential genes, 104 transcription factors were upregulated, and 45 were downregulated in NPCs. Neurogenesis related genes were upregulated in NPCs and the main non-redundant gene ontology (GO) terms enriched in NPCs were the autonomic nervous system, cell surface receptor signalling pathways), extracellular structure organisation, and programmed cell death. The main non-redundant GO terms enriched in MSCs included cytoskeleton organisation cytoskeleton structural constituent, mitotic cell cycle), and the mitotic cell cycle process Gene set enrichment analysis also confirmed cell cycle regulated pathways as well as Biocarta integrin pathway were upregulated in MSCs. Transcription factors enrichment analysis by ChEA3 revealed Foxs1 and HEYL, amongst the top five transcription factors, inhibits and enhances, respectively, the NPCs differentiation of MSCs.

Conclusions

The vast differences in the transcriptomic profiles between NPCs and MSCs revealed a set of markers that can identify the differentiation stage of NPCs as well as provide new targets to enhance MSCs differentiation into NPCs.
Genomics of asthma, allergy and chronic rhinosinusitis: novel concepts and relevance in airway mucosa
Authors: Laulajainen-Hongisto Anu , Lyly Annina , Hanif Tanzeela , Dhaygude Kishor , Kankainen Matti , Renkonen Risto , Donner Kati , Mattila Pirkko , Jartti Tuomas , Bousquet Jean , Kauppi Paula , Toppila-Salmi Sanna
Published: October 2020

Genome wide association studies (GWASs) have revealed several airway disease-associated risk loci. Their role in the onset of asthma, allergic rhinitis (AR) or chronic rhinosinusitis (CRS), however, is not yet fully understood. The aim of this review is to evaluate the airway relevance of loci and genes identified in GWAS studies. GWASs were searched from databases, and a list of loci associating significantly (p < 10–8) with asthma, AR and CRS was created. This yielded a total of 267 significantly asthma/AR–associated loci from 31 GWASs. No significant CRS -associated loci were found in this search. A total of 170 protein coding genes were connected to these loci. Of these, 76/170 (44%) showed bronchial epithelial protein expression in stained microscopic figures of Human Protein Atlas (HPA), and 61/170 (36%) had a literature report of having airway epithelial function. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation analyses were performed, and 19 functional protein categories were found as significantly (p < 0.05) enriched among these genes. These were related to cytokine production, cell activation and adaptive immune response, and all were strongly connected in network analysis. We also identified 15 protein pathways that were significantly (p < 0.05) enriched in these genes, related to T-helper cell differentiation, virus infection, JAK-STAT signaling pathway, and asthma. A third of GWAS-level risk loci genes of asthma or AR seemed to have airway epithelial functions according to our database and literature searches. In addition, many of the risk loci genes were immunity related. Some risk loci genes also related to metabolism, neuro-musculoskeletal or other functions. Functions overlapped and formed a strong network in our pathway analyses and are worth future studies of biomarker and therapeutics.
Understanding circular economy implementation in the agri-food supply chain: the case of an Indonesian organic fertiliser producer
Authors: Nattassha Ruth , Handayati Yuanita , Simatupang Togar M. , Siallagan Manahan
Published: October 2020

Background

One of the most important issues in the agri-food industry and its supply chain is the existence of by-products, treated as wastes and discarded immediately to waste disposal. This treatment might lead to loss of possibility in gaining economic value from them. Implementation of a circular economy could prevent the economic value loss, since the circular economy utilises said wastes as resources for other processes. However, the enforcement has obstacles and a lack of explanation in the literature, particularly in the case of an organic fertiliser producer.

Results and conclusions

This research develops a conceptual model of an organic fertiliser producer through the soft systems methodology approach. The results shed light on the ongoing literature by identifying the overall system and relevant components. Further, this study highlights several issues, the most important of which is the lack of interaction between the company and the farmers, which decrease the farmers’ desire to purchase the organic fertiliser. For better implementation of circular economy in this particular supply chain, it is suggested that the company establish better communication with their customers, the farmers, especially to gain better understanding of their wants and needs.
It hurts inside: a qualitative study investigating social exclusion and bullying among adolescents reporting frequent pain and high use of non-prescription analgesics
Authors: Skarstein Siv , Helseth Sølvi , Kvarme Lisbeth Gravdal
Published: October 2020

Background

Being bullied and socially excluded interferes with the fundamental need for humans to belong to a social group, which is necessary for well-being. This might underpin pain and the use of non-prescription analgesics.

Aim

The aim of the study was to gain insight into how social exclusion and bullying affect well-being in adolescents reporting frequent pain and high use of non-prescription analgesics.

Methods

A phenomenological hermeneutical method based on in-depth interviews was used. Nineteen teenagers, 14–16 years of age voluntarily participated in the study. Those included had frequent pain and used non-prescription analgesics daily or several times a week.

Results

Bullying and social exclusion affects thoughts, feelings and attitudes and thereby the quality of life of the adolescents we interviewed. They described feelings such as sadness, loneliness and depression, and a sense of being an outsider among peers was common. It also appears that bullying has significant potential to spread in a school environment.

Conclusion

The adolescents were self-aware and well-articulated. They conceptualised their experiences of being socially excluded and bullied. They described being socially excluded and bullied by peers as painful and they used non-prescription analgesics to alleviate pain. Teachers and health professionals should be aware of frequent pain and high use of non-prescribed analgesic medication as signs of psychosocial stress caused by social exclusion and bullying. Social exclusion and bullying should be systematically mapped, and targeted interventions implemented.
Oritavancin for the treatment of complicated gram-positive infection in persons who inject drugs
Authors: Ahiskali Aileen , Rhodes Heather
Published: October 2020

Background

Treatment of complicated infections in persons who inject drugs (PWID) and patients experiencing homelessness poses a unique challenge to clinicians. Long-acting lipoglycopeptide antibiotics, such as oritavancin, may facilitate extended courses of outpatient intravenous therapy while avoiding the need for central lines, improving compliance and thus increasing the chance of clinical cure.

Methods

Retrospective chart review of adult PWID who received at least one dose of oritavancin for a gram-positive infection between 1/1/17 and 6/30/19 at a large safety net hospital.

Results

Twenty three PWID received 24 courses of at least one dose of oritavancin for a gram-positive infection; 16 were experiencing homelessness at the time of diagnosis. Methicillin resistant Staphylococcus aureus (MRSA) was the most common infecting pathogen and bone or joint the most frequent infection site. Nineteen encounters resulted in clinical cure, including 5 whose conditions improved despite non-adherence to their prescribed regimen. Three patients experienced a non-favorable outcome. Two patients experienced mild adverse drug reactions that did not interfere with therapy; no patients died while on therapy.

Conclusion

Oritavancin may be a clinically effective treatment option for the management of complicated gram-positive infections in PWID and patients experiencing homelessness. Further studies should be performed to validate these results.
Intracellular dynamics of Ataxin-2 in the human brains with normal and frontotemporal lobar degeneration with TDP-43 inclusions
Authors: Watanabe Ryohei , Higashi Shinji , Nonaka Takashi , Kawakami Ito , Oshima Kenichi , Niizato Kazuhiro , Akiyama Haruhiko , Yoshida Mari , Hasegawa Masato , Arai Tetsuaki
Published: October 2020

TAR DNA-binding protein of 43 kDa (TDP-43) is a major component of intracellular aggregates formed in brains of the patients with frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS), which are correctively referred to as TDP-43 proteinopathies. A link between Ataxin-2 (ATXN2) and TDP-43 proteinopathies was established when intermediate CAG repeat expansions of ATXN2 gene were found to be associated with ALS and it was shown that ATXN2 modifies TDP-43 toxicity. Although ATXN2’s contribution to TDP-43 proteinopathies has been mostly studied in ALS, recent studies have shown that intermediate repeat expansions of ATXN2 also influence the phenotype of FTLD by an unknown mechanism. To address this issue, we immunohistochemically and biochemically analyzed the intracellular dynamics of ATXN2 in brains of normal controls and FTLD-TDP cases. The immunohistochemical studies revealed that ATXN2 localized in the neuronal cytoplasm and proximal dendrites, and expressed widely and uniformly in normal human brains. A semi-quantitative immunofluorescent analysis of normal brains revealed that the cytoplasmic ATXN2 strongly associates with ribosomal protein S6 and poly-A binding protein 1 and partially overlaps with the endoplasmic reticulum marker Calnexin, suggesting a major role of ATXN2 in protein synthesis. The results of immunohistochemical and biochemical analyses of brains from FTLD-TDP cases showed the colocalization of ATXN2 and phosphorylated TDP-43 in the dystrophic neurites and the neuronal cytoplasmic inclusions in the hippocampal region, and a significant reduction of ATXN2 protein compared to controls. These results suggest that ATXN2 is involved in the pathological process of FTLD-TDP. It remains to be clarified whether reduced ATXN2 expression induces neurodegeneration by impairing protein synthesis or plays a neuroprotective role by attenuating the toxicity of TDP-43 aggregates in FTLD-TDP and other TDP-43 proteinopathies.
Olfactory-colour crossmodal correspondences in art, science, and design
Authors: Spence Charles
Published: October 2020

The last few years have seen a rapid growth of interest amongst researchers in the crossmodal correspondences. One of the correspondences that has long intrigued artists is the putative association between colours and odours. While traditionally conceptualised in terms of synaesthesia, over the last quarter century or so, at least 20 published peer-reviewed articles have assessed the consistent, and non-random, nature of the colours that people intuitively associate with specific (both familiar and unfamiliar) odours in a non-food context. Having demonstrated such consistent mappings amongst the general (i.e. non-synaesthetic) population, researchers have now started to investigate whether they are shared cross-culturally, and to document their developmental acquisition. Over the years, several different explanations have been put forward by researchers for the existence of crossmodal correspondences, including the statistical, semantic, structural, and emotional-mediation accounts. While several of these approaches would appear to have some explanatory validity as far as the odour-colour correspondences are concerned, contemporary researchers have focussed on learned associations as the dominant explanatory framework. The nature of the colour-odour associations that have been reported to date appear to depend on the familiarity of the odour and the ease of source naming, and hence the kind of association/representation that is accessed. While the bidirectionality of odour-colour correspondences has not yet been rigorously assessed, many designers are nevertheless already starting to build on odour-colour crossmodal correspondences in their packaging/labelling/branding work.
User experiences on implementation of patient reported outcome measures (PROMs) in a Haematological outpatient clinic
Authors: Thestrup Hansen Stine , Kjerholt Mette , Friis Christensen Sarah , Brodersen John , Hølge-Hazelton Bibi
Published: October 2020

Background

PROMs can help healthcare professionals gain an improved understanding of patients’ physical burdens, functional levels, and (health-related) quality of life throughout disease and medical treatment. The aim of this study was to investigate the barriers and potential opportunities PROMs may present in a haematological outpatient clinic from three different perspectives: patients, nurses and haematologists.

Methods

The present study synthesizes three previously published studies that separately explored the experiences of patients, nurses and haematologists when implementing PROMs. The studies were all guided by the qualitative methodology Interpretive Description, including a focused ethnographic approach, to develop implications for future practice.

Results

The overall themes that emerged from the analysis were “Structural similarities influence the adoption of PROMs” and “Different perspectives on the potential of PROMs.”

Conclusion

Across the different user groups in the haematological outpatient clinic, the use of PROMs was thwarted due to an unquestioned commitment to biomedical knowledge and the system’s rationality and norms: PROM data was not used in patient consultations. Nurses and haematologists expressed different preferences related to potential future PROMs and different objectives for PROMs in clinical practice. From the different perspectives of the patients, nurses and haematologists, PROMs were not compatible with clinical practice. Further research is recommended to develop PROMs validated for use in haematological outpatient clinics. Moreover, implementation strategies adjusted to the structural barriers of the system are crucial.
The role of nicotinic receptors in SARS-CoV-2 receptor ACE2 expression in intestinal epithelia
Authors: ten Hove Anne S. , Brinkman David J. , Li Yim Andrew Y. F. , Verseijden Caroline , Hakvoort Theo B. M. , Admiraal Iris , Welting Olaf , van Hamersveld Patricia H. P. , Sinniger Valérie , Bonaz Bruno , Luyer Misha D. , de Jonge Wouter J.
Published: October 2020

Background

Recent evidence demonstrated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) propagates in intestinal epithelial cells expressing Angiotensin-Converting Enzyme 2 (ACE2), implying that these cells represent an important entry site for the viral infection. Nicotinic receptors (nAChRs) have been put forward as potential regulators of inflammation and of ACE2 expression. As vagus nerve stimulation (VNS) activates nAChRs, we aimed to investigate whether VNS can be instrumental in affecting intestinal epithelial ACE2 expression.

Methods

By using publicly available datasets we qualified epithelial ACE2 expression in human intestine, and assessed gene co-expression of ACE2 and SARS-CoV-2 priming Transmembrane Serine Protease 2 (TMPRSS2) with nAChRs in intestinal epithelial cells. Next, we investigated mouse and human ACE2 expression in intestinal tissues after chronic VNS via implanted devices.

Results

We show co-expression of ACE2 and TMPRSS2 with nAChRs and α7 nAChR in particular in intestinal stem cells, goblet cells, and enterocytes. However, VNS did not affect ACE2 expression in murine or human intestinal tissue, albeit in colitis setting.

Conclusions

ACE2 and TMPRSS2 are specifically expressed in epithelial cells of human intestine, and both are co-expressed with nAChRs. However, no evidence for regulation of ACE2 expression through VNS could be found. Hence, a therapeutic value of VNS with respect to SARS-CoV-2 infection risk through ACE2 receptor modulation in intestinal epithelia could not be established.
A comparative study of the phenotype with kainic acid-induced seizure in DBA/2 mice from three different sources
Authors: Kang Kyung-Ku , Kim Young-In , Seo Min-Soo , Sung Soo-Eun , Choi Joo-Hee , Lee Sijoon , Jung Young-Suk , Cho Joon Young , Hwang Dae Youn , Park Sang-Joon , Kim Kil Soo
Published: October 2020

The kainic acid-induced seizure mouse model is widely used in epilepsy research. In this study, we applied kainic acid to the subcutaneous injections of three different sources of DBA/2 mice to compare and evaluate the seizure response. The three mouse sources consisted of DBA/2Kor1 (Korea FDA source), DBA/2A (USA source), and DBA/2 (Japan source), and were purchased from different vendors. To compare the responses of DBA/2 mice to kainic acid injections, we examined the survival rate, seizure phenotype scoring, and behavioral changes. We also evaluated brain lesions using histopathological analysis. Following the administration of kainic acid, almost half of the cohort survived, and the seizure phenotype displayed a moderate level of sensitivity (2 ~ 4 out of 6). In the histopathologic analysis, there was no change in morphological features, and levels of glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1 (Iba-1) increased in the kainic acid-treated groups. However, there was no difference in the neuronal nuclei (NeuN) expression level. All the data showed that the responses in the kainic acid-treated group were similar across the three strains. In conclusion, our results suggest that the three sources of DBA/2 mice (DBA/2Kor1, DBA/2A, and DBA/2B) have similar pathological responses to kainic acid-induced seizures.
Anti-Helicobacter pylori activity of acomplex mixture of Lactobacillus paracasei HP7 including the extract of Perilla frutescens var. acuta and Glycyrrhiza glabra
Authors: Lee Hyun-A , Kim Joo-Yun , Kim Jisoo , Nam Bora , Kim Okjin
Published: October 2020

The effect of standard therapeutic strategies on Helicobacter pylori infection is diminished over time owing to the emergence of drug resistant strains. In this study, we would like to confirm the enhanced effect of L. paracasei HP7, which has been reported to exert antibacterial and gastric mucosal protective effects, in combination with Perilla frutescens var. acuta (P. frutescens)and Glycyrrhiza glabra (G. glabra) extracts.

P. frutescens extract and G. glabra extract were found to inhibit the growth of H. pylori in a concentration-dependent manner, and the combination of L. paracasei HP7 and P. frutescens extract and G. glabra extract effectively inhibited H. pylori from attaching to AGS a gastric epithelial cells. Moreover, L. paracasei HP7 complex mixture containing P. frutescens and G. glabra extracts has been shown to inhibit H. pylori virulence genes such as AlpA, CagA, FlaA and UreA. When H. pylori-infected mice were administered a complex mixture of L. paracasei HP7 containing P. frutescens and G. glabra extract, the infection rate of H. pylori was significantly reduced. In addition, the L. paracasei HP7 complex mixture significantly reduced serum IL-8 levels and stomach inflammation in H. pylori infected mice.

These results suggest that a complex mixture of L. paracasei HP7 containing P. frutescens and G. glabra extracts may be an alternative to treating diseases caused by H. pylori infection.
Field apple scab susceptibility of a diverse
Malus
germplasm collection identifies potential sources of resistance for apple breeding
Authors: Papp David , Gao Liqiang , Thapa Ranjita , Olmstead Dan , Khan Awais
Published: October 2020

Background

Breeding for resistance to apple scab (caused by
Venturia inaequalis
), the most devastating fungal disease of apples, relies on genetic resources maintained in germplasm collections.

Methods

To identify new sources of scab resistance, we evaluated 177
Malus
accessions, including 27 primary and 13 hybrid
Malus
species from diverse geographical origins, in an orchard at Geneva, New York. We also screened a differential host set for 2 years to monitor for changes in the effectiveness of ten known scab resistance genes, which allowed us to confirm the presence of virulent pathogen races in the orchard.

Results

We found that ~ 37% of the wild
Malus
accessions and domesticated cultivars were resistant to apple scab in the field. Several of these accessions were unrelated to sources of previously known resistance genes and are promising for apple scab genetic research and resistance breeding. Cultivars carrying the
Rvi6
(
Vf
) gene from
Malus floribunda
clone 821, e.g. ‘Liberty’ or ‘Florina’, remained resistant despite the breakdown of
Rvi6
. ‘Demir’, a
Malus
hybrid from Turkey, and ‘Chisel Jersey’, a traditional English hard cider cultivar, showed fewer symptoms than the
Rvi6
resistant cultivar ‘Prima’. Races 1 to 7 and 9 of
V. inaequalis
were present in the orchard, but no scab was observed on the indicator host accessions for races 11 and 12.

Conclusions

Detailed and systematic screening of
Malus
germplasm identified resistant and moderately resistant donor accessions based on resistance reaction types. These accessions are promising for use in future genetic studies to identify novel sources of scab resistance alleles for apple breeding to develop cultivars with durable apple scab resistance.
Reading New Asian Tropicalities in Contemporary Singapore
Authors: Leow Joanne
Published: October 2020

This essay theorizes the cultivation, suppression, and cooptation of new forms of Asian tropicality in the material and cultural productions of contemporary Singapore. Originating in Anglo-American imperial discourse of the eighteenth century, tropicality suggests the social construction of the “tropics” as a space in opposition to European and North American temperate environments. Reading the material space of the massive eco-development Gardens by the Bay and a series of contemporary literary texts by Kevin Kwan, Sandi Tan, and Ng Yi-Sheng, the author argues that these texts produce and reflect a contemporary cultural moment that is predicated on climate control and environmental engineering and haunted by the legacies of coloniality and developmental politics. The theorization of new Asian tropicalities provides a new critical lens with which to consider the relationships and connections between these constructions of nature and the material and cultural texts of twenty-first-century Singapore—a model of urban ecology that has an outsized influence on other Asian cities.
Seasonal Liquidity, Rural Labor Markets, and Agricultural Production
Authors: Fink Günther , Jack B. Kelsey , Masiye Felix
Published: October 2020

Rural economies in many developing countries are characterized by a lean season in the months preceding harvest, when farmers have depleted their cash and grain savings from the previous year. To identify the impacts of liquidity during the lean season, we offered subsidized loans in randomly selected villages in rural Zambia. Ninety-eight percent of households took up the loan. Loan eligibility led to increases in on-farm labor and agricultural output, driving up wages in local labor markets. Larger effects for poorer households suggest that liquidity constraints contribute to inequality in rural economies. (JEL O13, O15, O18, Q11, Q12, R23)
A review of dental cone-beam CT dose conversion coefficients
Authors: Mah Eugene , Ritenour E Russell , Yao Hai
Published: October 2020

Objective:

The purpose of this study was to review the literature to examine the usage and magnitude of effective dose conversion factors (DCE) for dental cone beam CT (CBCT) scanners.

Methods:

A PubMed literature search for publications relating to radiation dosimetry in dental radiography was performed. Papers were included if they reported DCE, or reported ICRP 103 effective dose and dose-area product. 71 papers relating to dental CBCT dosimetry were found, of which eight reported effective dose conversion factors or provided enough information to calculate dose conversion factors. Scanner model, effective dose, dose-area product, tube voltage, field of view size and DCEwere extracted from the papers for analysis.

Results:

DCEvalues ranged from 0.035 to 0.31 µSv/mGy-cm2with a mean of 0.129 µSv/mGy-cm2(SD = 0.056). When categorized into small (<100 cm2), medium (100–225 cm2) and large (>225 cm2) fields of view (FOV), linear fits to the effective dose and dose-area product yielded slopes of 0.129, 0.111 and 0.074 µSv/mGy-cm2for small, medium and large FOVs respectively.

Conclusion:

The range of reported DCEvalues and spread with respect to field of view category suggests that DCEvalues that depend on FOV would provide more accurate effective dose estimates. Tube voltage was found to be a smaller factor in determining DCE. Reasonable values for DCEtaking into account FOV size were obtained. There is considerable room for more work to be done to examine the behaviour of DCEwith changes to patient age and dental CBCT imaging parameters.
Experience of communication among cervical cancer patients in Kenya
Authors: Caren Jerop , Mose George , Kurgat Kibiwott
Published: October 2020

Communication influences patient disclosure, treatment adherence, and outcome, adaptation to illness, and bereavement. Different cancer patients and caregivers communicate their various experiences in unique ways. These distinctive experiences are necessary to be told, because it empowers both the teller and everyone who hears and shares that experience. However, there is little research documenting the experiences of cervical cancer patients and caregivers in Kenya and the rest of Africa. This study therefore sought to assess the communication experience among cervical cancer patients and their caregivers. This study was a qualitative study employing the phenomenological method to obtain data from cervical patients and caregivers. It was carried out in Uasin Gishu County, Kenya, where a range of in-depth interviews were held with eight patients and eight caregivers purposively sampled. Data from the interviews were analysed thematically and presented in narrative form using paraphrases and quotations. Ethical issues such as informed consent, confidentiality and official authorisation were observed at all levels. To enrich this study, hermeneutic theory, which explains more about the individual's experience, was used. The findings of the study indicated that communication is therapeutic, although most of the patients and the caregivers were reluctant to talk about their illness. The findings of this study will be of interest to scholars, policy-makers and caregivers of terminally ill patients.
Difficulties Encountered by High School Students in Mathematics
Authors: Guner Necdet
Published: October 2020

The aim of this study is to identify whether high school students encounter any difficulties in mathematics and reveal the reasons for such difficulties. The participants of the study, which was a descriptive case study based on qualitative understanding, were a total of 164 students, including 85 students from Anatolian High Schools and 79 students from Science High Schools. Approximately 11% of the participants said they had no difficulties in math, whereas 99% of the students from Anatolian High Schools and 78% of the students from Science High Schools said they had difficulties in mathematic. Their thoughts about the reasons for such difficulties were analyzed by content analysis method considering the type of high school they attended. The findings obtained revealed that the difficulties encountered by the participants in mathematics were teacher-, content- and student-based. Anatolian High School students stated that they intensely faced teacher-based difficulties, whereas Science High School students stated that they faced content-based difficulties. It's expected that the results of this study may contribute to studies to be conducted to increase student success in mathematics education and provide ideas for further studies.
Polarizer calibration method for Mueller matrix polarimeters
Authors: Ossikovski Razvigor , Al Bugami Bandar , Garcia-Caurel Enrique , Cloude Shane R.
Published: October 2020

We advance what we believe is a novel eigenvalue-based method for calibrating Mueller matrix polarimeters employing a single calibration optical component: a polarizer. The method is potentially advantageous in high numerical aperture imaging or wide spectral range spectroscopic polarimetric configurations restricting or even prohibiting the standard use of a retarder as a second calibration component.
Study on deformation evolution law of coal under asymmetric loading by digital image correlation
Authors: Wang Tao , Zhao Hongbao , Ge Lina , Zhang Huan , Liu Rui
Published: October 2020

In this paper, the digital image correlation was innovatively applied
to study the deformation and damage process of raw coal and briquette
under a complex stress environment. The results show that under
symmetrical loading, briquette coal shows tensile failure and that the
strain field goes through three stages. The raw coal shows shear
failure; the stage characteristic of the strain field is not obvious.
Under asymmetric loading, the strain field evolution of raw coal and
briquette shows three characteristic stages, but the briquette is more
likely to form a localization phenomenon. The displacement value of
the crack in the shear direction is greater than that in the tension
direction, so the raw coal and briquette mainly undergo shear failure.
The localized starting stress is determined by the defined statistical
index function, and the localized starting stress of the raw coal and
the briquette coal has a quadratic function relationship with the
asymmetric coefficient.
Effect of optical energy modulation on the thermal response of biological tissue: computational and experimental validations
Authors: Tran Van Nam , Truong Van Gia , Lee Yong Wook , Kang Hyun Wook
Published: October 2020

This study develops an energy modulation technique to attain a constant interstitial tissue temperature and to induce the predetermined thermal coagulation without carbonization in tissue. An optical diffuser was employed to deliver 1064 nm light to the biological tissue. The combined mode maintained the interstitial temperature at 70 ℃ for longer durations compared to the continuous wave mode. Coagulation volumes increased linearly with the time and met the predetermined treatment volume range (0.32–0.52 cm3) after the combined treatment for 100 s. The combined modulation can be a feasible modality to induce the predetermined extent of thermal coagulation for treating papillary thyroid microcarcinoma.
Multi-beam OCT imaging based on an integrated, free-space interferometer
Authors: Kim Yongjoo , Lippok Norman , Vakoc Benjamin J.
Published: October 2020

While it is a common practice to increase the speed of swept-source optical coherence tomography (OCT) systems by using a high-speed source, this approach may not always be optimal. Parallelization in the form of multiple imaging beams is an alternative approach, but scalable and low-loss multi-beam OCT architectures are needed to capitalize on its advantages. In this study, we demonstrate an eight-beam OCT system using an interferometer architecture comprising planar lightwave circuits (PLC) splitters, V-groove assemblies (VGA), and optical ribbon fibers. We achieved an excess loss and heterodyne efficiency on each channel that was close to that of single-beam systems. In vivo structural imaging of a human finger and OCT angiography imaging of a mouse ear was performed to demonstrate the imaging performance of the system. This work provides further evidence supporting multi-beam architectures as a viable strategy for increasing OCT imaging speed.
2 × 2 anisotropic transfer matrix approach for optical propagation in uniaxial transmission filter structures
Authors: AL-Ghezi Hammid , Gnawali Rudra , Banerjee Partha P. , Sun Lirong , Slagle Jonathan , Evans Dean
Published: October 2020

Multi-layered metamaterial structures show promise in a wide variety of optical applications such as superlenses, electromagnetic cloaking, tunable filters, sensors, and spatial light modulators. Optical transmission analysis of multilayer metallo-dielectric stacks with overall thickness less than the wavelength of light can be modeled using effective medium theory and the Berreman matrix method. For multilayer anisotropic stacks of arbitrary thickness, a rigorous 4 × 4 transfer matrix embodiment is typically used. In this work, a 2 × 2 anisotropic transfer matrix method is developed to analyze optical propagation through multilayer uniaxial stacks of arbitrary thicknesses. Optical transmission of a multilayer silver–zinc oxide stack deposited on a quartz substrate is modeled with this 2 × 2 anisotropic transfer matrix method and reconciled with experimental observations. Results indicate that this numerical approach is applicable to in situ assessment of the complex refractive indices of constituent metal and dielectric layers. Additionally, the anisotropic 2 × 2 transfer matrix method enables the possibility of modeling the transmission of the same metallo-dielectric structure deposited on an electro-optic, uniaxial substrate. Simulation results predict that adjusting the bias field across the substrate results in an electrically tunable transmission filter.
Shack-Hartmann wavefront sensing using spatial-temporal data from an event-based image sensor
Authors: Kong Fanpeng , Lambert Andrew , Joubert Damien , Cohen Gregory
Published: October 2020

An event-based image sensor works dramatically differently from the conventional frame-based image sensors in a way that it only responds to local brightness changes whereas its counterparts’ output is a linear representation of the illumination over a fixed exposure time. The output of an event-based image sensor therefore is an asynchronous stream of spatial-temporal events data tagged with the location, timestamp and polarity of the triggered events. Compared to traditional frame-based image sensors, event-based image sensors have advantages of high temporal resolution, low latency, high dynamic range and low power consumption. Although event-based image sensors have been used in many computer vision, navigation and even space situation awareness applications, little work has been done to explore their applicability in the field of wavefront sensing. In this work, we present the integration of an event camera in a Shack-Hartmann wavefront sensor and the usage of event data to determine spot displacement and wavefront estimation. We show that it can achieve the same functionality but with substantial speed and can operate in extremely low light conditions. This makes an event-based Shack-Hartmann wavefront sensor a preferable choice for adaptive optics systems where light budget is limited or high bandwidth is required.
Frequency-domain optical coherence tomography with undetected mid-infrared photons
Authors: Vanselow Aron , Kaufmann Paul , Zorin Ivan , Heise Bettina , Chrzanowski Helen M. , Ramelow Sven
Published: October 2020

Mid-infrared (mid-IR) light scatters much less than shorter wavelengths, allowing greatly enhanced penetration depths for optical imaging techniques such as optical coherence tomography (OCT). However, both detection and broadband sources in the mid-IR are technologically challenging. Interfering entangled photons in a nonlinear interferometer enables sensing with undetected photons, making mid-IR sources and detectors obsolete. Here we implement mid-IR frequency-domain OCT based on ultra-broadband entangled photon pairs spanning from 3.3 to 4.3 µm. We demonstrate 10 µm axial and 20 µm lateral resolution 2D and 3D imaging of strongly scattering ceramic and paint samples. By intrinsically being limited only by shot noise, we observe

times more sensitivity per integration time and power of the probe light. Together with the vastly reduced footprint and technical complexity, our technique can outperform conventional approaches with classical mid-IR light sources.
Superconducting nanowire single-photon detectors with 98% system detection efficiency at 1550  nm
Authors: Reddy Dileep V. , Nerem Robert R. , Nam Sae Woo , Mirin Richard P. , Verma Varun B.
Published: October 2020

Superconducting nanowire single-photon detectors (SNSPDs) are an enabling technology for myriad quantum-optics experiments that require high-efficiency detection, large count rates, and precise timing resolution. The system detection efficiencies (SDEs) for fiber-coupled SNSPDs have fallen short of theoretical predictions of near unity by at least 7%, with the discrepancy being attributed to scattering, material absorption, and other SNSPD dynamics. We optimize the design and fabrication of an all-dielectric layered stack and fiber coupling package in order to achieve

98.0
±
0.5
%

SDE, measured for single-mode-fiber guided photons derived from a highly attenuated 1550 nm continuous-wave laser. This enforces a smaller bound on the scattering and absorption losses in such systems and opens the use of SNSPDs for scenarios that demand high-SDE for throughput and fidelity.
Bernardino António Gomes (1768-1823): a quina e o isolamento da cinchonina
Authors: Semedo Maria Guilherme
Published: October 2020

Bernardino António Gomes (1768-1823) foi um eminente médico e cientista português que se destacou particularmente no domínio da química, com o isolamento da cinchonina a partir da casca de quina, uma planta antimalárica. Este isolamento foi descrito no Ensaio sobre o cinchonino (1812) e desencadeou uma acérrima polémica entre Gomes e os redatores do Jornal de Coimbra. Adicionalmente, teve um importante papel noutras áreas: na saúde pública portuguesa, fundando a Instituição Vacínica e promovendo o uso da vacina jenneriana; na dermatologia, escrevendo o primeiro livro português versando inteiramente sobre doenças da pele; e na botânica, dedicando-se ao estudo de diversas plantas no Brasil, como a ipecacuanha ou a canela. A sua obra teve ampla repercussão internacional, sobretudo em França.
1968, el año del cambio en el Perú
Authors: Jancsó Katalin
Published: October 2020

Según muchos expertos, 1968 fue un año mítico que causó cambios en varias partes del mundo. En octubre del mismo año, cambios determinantes se llevaron a cabo también en el Perú con la llegada al poder del general Juan Velasco Alvarado. Las medidas introducidas sobre todo durante el primer periodo de su régimen tuvieron efectos a largo plazo e irreversibles en la sociedad y economía del país andino. El presente artículo se propone analizar y reflexionar sobre los acontecimientos de las primeras semanas, las circunstancias de la formación de su gobierno, la reacción del gobierno húngaro ante los sucesos, así como los primeros pasos para establecer relaciones diplomáticas entre Hungría y Perú, basándose en los artículos de dos fuentes hemerográficas húngaras contemporáneas, los periódicos Népszabadság y Népszava.
Defining the Caribbean Area and Identity
Authors: Tézer Zita
Published: October 2020

In examining Caribbean identity, it is essential to examine the demarcation of the area, delimit the boundaries, assess how local people have defined or redefined themselves in space and time, and how this is influenced by economics and politics. Obviously the key is the geographic proximity of the Caribbean Sea and its history, which result in many similarities in time, but there is variation, and there are differences. Two significant researchers who investigated the most important common elements like colonization, plantation economy and slavery, Charles Wagley and Sidney Mintz cultural anthropologists, conducted their fieldwork in Brazil, Puerto Rico, Haiti and Jamaica. In defining the “Caribbean” within Plantation America cultural sphere, Charles Wagley took into account the geography, the environment, linguistics, the modes of production, the local histories. Both anthropologists made sociocultural, ethnographic and demographic analyses, comparing the colonial structures in the plantations to delimit the culturally identical area, which, however, today is not followed by geopolitical boundaries, nor is the locals' perceptions of their own interpretation about the Caribbean area.