bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth-uncoupled isoprenoid synthesis in Rhodobacter sphaeroides
Authors: Orsi Enrico , Mougiakos Ioannis , Post Wilbert , Beekwilder Jules , Dompè Marco , Eggink Gerrit , van der Oost John , Kengen Servé W. M. , Weusthuis Ruud A.
Published: July 2020

Background

Microbial cell factories are usually engineered and employed for cultivations that combine product synthesis with growth. Such a strategy inevitably invests part of the substrate pool towards the generation of biomass and cellular maintenance. Hence, engineering strains for the formation of a specific product under non-growth conditions would allow to reach higher product yields. In this respect, isoprenoid biosynthesis represents an extensively studied example of growth-coupled synthesis with rather unexplored potential for growth-independent production. Rhodobacter sphaeroides is a model bacterium for isoprenoid biosynthesis, either via the native 2-methyl-d-erythritol 4-phosphate (MEP) pathway or the heterologous mevalonate (MVA) pathway, and for poly-β-hydroxybutyrate (PHB) biosynthesis.

Results

This study investigates the use of this bacterium for growth-independent production of isoprenoids, with amorpha-4,11-diene as reporter molecule. For this purpose, we employed the recently developed Cas9-based genome editing tool for R. sphaeroides to rapidly construct single and double deletion mutant strains of the MEP and PHB pathways, and we subsequently transformed the strains with the amorphadiene producing plasmid. Furthermore, we employed 13C-metabolic flux ratio analysis to monitor the changes in the isoprenoid metabolic fluxes under different cultivation conditions. We demonstrated that active flux via both isoprenoid pathways while inactivating PHB synthesis maximizes growth-coupled isoprenoid synthesis. On the other hand, the strain that showed the highest growth-independent isoprenoid yield and productivity, combined the plasmid-based heterologous expression of the orthogonal MVA pathway with the inactivation of the native MEP and PHB production pathways.

Conclusions

Apart from proposing a microbial cell factory for growth-independent isoprenoid synthesis, this work provides novel insights about the interaction of MEP and MVA pathways under different growth conditions.
Laboratory colonization by Dirofilaria immitis alters the microbiome of female Aedes aegypti mosquitoes
Authors: Adegoke Abdulsalam , Neff Erik , Geary Amie , Husser Montana Ciara , Wilson Kevin , Norris Shawn Michael , Dharmarajan Guha , Karim Shahid
Published: July 2020

Background

The ability of blood-feeding arthropods to successfully acquire and transmit pathogens of medical and veterinary importance has been shown to be interfered with, or enhanced by, the arthropod’s native microbiome. Mosquitoes transmit viruses, protozoan and filarial nematodes, the majority of which contribute to the 17% of infectious disease cases worldwide. Dirofilaria immitis, a mosquito-transmitted filarial nematodes of dogs and cats, is vectored by several mosquito species including Aedes aegypti.

Methods

In this study, we investigated the impact of D. immitis colonization on the microbiome of laboratory reared female Ae. aegypti. Metagenomic analysis of the V3–V4 variable region of the microbial 16S RNA gene was used for identification of the microbial differences down to species level.

Results

We generated a total of 1068 OTUs representing 16 phyla, 181 genera and 271 bacterial species. Overall, in order of abundance, Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes were the most represented phylum with D. immitis-infected mosquitoes having more of Proteobacteria (71%) than uninfected mosquitoes (56.9%). An interesting finding in this study is the detection of Klebsiella oxytoca in relatively similar abundance in infected and uninfected mosquitoes, suggesting a possible endosymbiotic relationship, and has been previously shown to indirectly compete for nutrients with fungi on domestic housefly eggs and larvae. While D. immitis colonization has no effect on the overall species richness, we identified significant differences in the composition of selected bacterial genera and phyla between the two groups. We also reported distinct compositional and phylogenetic differences in the individual bacterial species when commonly identified bacteria were compared.

Conclusions

To the best of our knowledge, this is the first study to understand the impact of a filarial infection on the microbiome of its mosquito vector. Further studies are required to identify bacteria species that could play an important role in the mosquito biology. While the microbiome composition of Ae. aegypti mosquito have been previously reported, our study shows that in an effort to establish itself, a filarial nematode modifies and alters the overall microbial diversity within its mosquito host.
Age, source, and future risk of COVID-19 infections in two settings of Hong Kong and Singapore
Authors: Zhu Shuying , Tao Jun , Gao Huizhi , He Daihai
Published: July 2020

Objective

To explore and compare the age, source and future risk of COVID-19 infection in Hong Kong SAR China and Singapore as of March 5, 2020.

Results

We find significant difference in age patterns of confirmed cases in these 2 localities early in the pandemic.

Conclusion

We highlight the potential importance of population age structure in confirmed cases, which should be considered in evaluation of the effectiveness of control effort in different localities.
Cerebral organoids as tools to identify the developmental roots of autism
Authors: Chan Wai Kit , Griffiths Rosie , Price David J. , Mason John O.
Published: July 2020

Some autism spectrum disorders (ASD) likely arise as a result of abnormalities during early embryonic development of the brain. Studying human embryonic brain development directly is challenging, mainly due to ethical and practical constraints. However, the recent development of cerebral organoids provides a powerful tool for studying both normal human embryonic brain development and, potentially, the origins of neurodevelopmental disorders including ASD. Substantial evidence now indicates that cerebral organoids can mimic normal embryonic brain development and neural cells found in organoids closely resemble their in vivo counterparts. However, with prolonged culture, significant differences begin to arise. We suggest that cerebral organoids, in their current form, are most suitable to model earlier neurodevelopmental events and processes such as neurogenesis and cortical lamination. Processes implicated in ASDs which occur at later stages of development, such as synaptogenesis and neural circuit formation, may also be modeled using organoids. The accuracy of such models will benefit from continuous improvements to protocols for organoid differentiation.
Intelligent algorithms for cold chain logistics distribution optimization based on big data cloud computing analysis
Authors: Chen Yi-hua
Published: July 2020

In recent years, the rapid development of fresh food e-commerce in China has brought about more development opportunities for the cold chain logistics industry but has also presented new challenges. With the development of cloud computing and big data technology, it is increasingly important to study the application of big data and cloud computing technology in cold chain logistics. The purpose of this paper is to study the intelligent algorithm of cold chain logistics distribution optimization based on big data cloud computing analysis. Based on the constituent elements of the cold chain distribution problem and using cloud computing technology to obtain real-time traffic information in the transportation system through a unified access interface, this article analyses the distribution time and cost of refrigerated vehicles, thereby establishing a cold chain distribution vehicle path optimization model. By analysing the parallel programming mode of cloud computing, the parallel design and analysis of a coarse-grained genetic algorithm are used to solve the simulation model of the established optimization model. The experimental results show that the method of optimizing cold chain logistics vehicle routing using cloud computing is effective. When comparing 1, 2, 4, and 8 processors, the execution times are 19.89, 14.52, 8.12, and 6.41, respectively. It can be seen that the more processors there are, the shorter the calculation time.
Soluble IL-2Rα correlates with imbalances of Th1/Th2 and Tc1/Tc2 cells in patients with acute brucellosis
Authors: Sun Hua-Li , Ma Cheng-Jie , Du Xiu-Fang , Yang Si-Yuan , Lv Xiao , Zhao Hong , Wang Ling-Hang , Tang Yun-Xia , Li Xing-Wang , Jiang Rong-Meng
Published: July 2020

Background

Previous studies showed that soluble IL-2Rα is an important marker of cellular immune activation and might be a marker of treatment efficacy for children with brucellosis. However, data regarding adult patients with brucellosis were unknown. The aim of study was to explore the potential role of serum sIL-2Rα evaluating treatment responses in adult patients with brucellosis, and T cell immune status was also examined.

Methods

During January 2016–April 2017, 30 patients with acute brucellosis from the Third People’s Hospital of Linfen in Shanxi Province and Beijing Di Tan Hospital, and 28 healthy controls were included in this study. Peripheral blood samples were collected before and after six weeks of antibiotic treatment. Serum sIL-2Rα levels were measured by enzyme-linked immunosorbent assay, and the percentage of Th1, Th2, Tc1, Tc2, and Tregs was detected by flow cytometry after intracellular staining for cytokines (interferon-γ and interleukin-4) and Foxp3 in T lymphocytes from peripheral blood. The obtained data were analyzed with Wilcoxon ranked sum tests for paired values, Mann-Whitney U-tests for comparisons between patients and healthy controls, and Spearman rank tests for correlation analyses.

Results

Serum sIL-2Rα levels were significantly higher in patients than in controls (P = 0.001). A significant decline was observed in patients after the cessation of treatment (P < 0.001) and return to normal (P > 0.05). Th1, Tc1, Th2, and Tc2 cell frequencies were higher in patients than in healthy subjects (P < 0.05), while the Th1/Th2 and Tc1/Tc2 ratios were significantly lower (P = 0.0305 and 0.0005, respectively) and returned to normal levels after treatment. In patients with acute brucellosis, serum sIL-2Rα levels were negatively correlated with the Th1/Th2 ratio (r = − 0.478,P = 0.028), Tc1/Tc2 ratio (r = − 0.677,P = 0.001), and Tc1 percentage (r = − 0.516,P = 0.017). Serum sIL-2Rα and Tc2 percentages were positively correlated (r = 0.442,P = 0.045).

Conclusions

Based on the correlations with Th1/Th2 and Tc1/Tc2 ratios, serum sIL-2Rα levels may reflect the immune response status. sIL-2Rα may be a marker for therapeutic efficacy in acute brucellosis.
Correction to: Temporal trend of research related to gun violence from 1981 to 2018 in the United States: a bibliometric analysis
Authors: Chien Lung-Chang , Gakh Maxim , Coughenour Courtney , Lin Ro-Ting
Published: July 2020

An amendment to this paper has been published and can be accessed via the original article.
A multimethod paleointensity approach applied to the historical Xitle lava flows (Central Mexico): towards the accurate paleointensity determination
Authors: Morales Juan , Pérez-Rodríguez Nayeli , Goguitchaichvili Avto , Cervantes-Solano Miguel
Published: July 2020

An inclusive rock-magnetic and absolute paleointensity survey of the ~ 2-ka-old Xitle volcano (southerly Basin of Mexico) was undertaken to assess the faithfulness of the paleomagnetic log carried by fresh, widely exposed and well-preserved lava flows. Paleomagnetic samples from six lava flows were subjected to paleointensity analysis with a multi-method approach: the Thellier–Coe, IZZI, and multi-specimen methods. Overall mean flow PI values from flows 4–6 obtained by the Thellier-type methods used yielded 68.4 µT (σ = ± 5.6 µT), 63.9 µT (σ = ± 5.8 µT) and 61.5 µT (σ = ± 4.3 µT) for the TC, IZZI, and IZZI with CR correction methods, respectively. Although multi-specimen paleointensity results were, in general, lower than that obtained with the other methods for the same flows, that for Flow 5 (61.8 µT) was very similar to those obtained with the Thellier-type methods. Based on the results obtained, this lava flows sequence could correspond to two eruptive periods; one related with the Xitle volcano (flows 3–6), and another older (flows 1 and 2). The combined archeomagnetic dating of the different flows reinforces this hypothesis, as well as the multi-modal distribution for the age of the Xitle, proposed two decades ago. The application of stricter acceptance criteria and consideration of cooling-rate correction could slightly reduce the scattered observations. The multi-method approach employed under this study, combined with detailed rock-magnetic experiments, may definitively increase the accuracy of paleointensity determinations.
Comparison of conventional and automated freezing methods on PB2 rooster semen cryopreserved with glycerol and dimethylsulfoxide tris coconut-water extender
Authors: Balogun Adedeji Suleimon , Narang Raman , Cheema Ranjna S. , Kumar Ajeet , Singh Narinder , Vijaysingh Malik
Published: July 2020

Background

Poultry semen cryopreservation remains an easy and promising way of preserving and transferring poultry germplasm. Standardizing and optimizing freezing procedure with natural extender may be a reliable step towards achieving better post-thawed sperm quality. This study was conducted to investigate the effects of four different freezing protocols (FP) on frozen rooster semen extended with tris coconut water extender (TCWE). A total of 20 roosters were used and trained for semen collection. TCWE was prepared by adding coconut water to tris buffer and kept at 37 °C. Semen was collected and pooled from the roosters and was evaluated for motility before dilution procedure. Three different concentrations (8, 10, and 15%) of two intracellular cryoprotectants glycerol and dimethylsulfoxide (DMSO) were supplemented in TCWE. Pooled semen was divided into six equal fractions, and TCWE containing cryoprotectants in different concentrations were diluted with the semen in ratio 1:2 (semen:extender). Diluted semen was manually filled in 0.25 ml straws and sealed. Semen straws were equilibrated for 4 h at 4 °C. Each straw fraction was further divided into four parts, and subjected to four FP (slow freezing 1, 2, 3 and fast freezing 4). Each FP was done on samples containing 8, 10, and 15% glycerol and 8, 10, and 15% DMSO. After each protocol, semen straws were finally deep into liquid nitrogen – 196 °C. After 48 h, the straws were thawed individually to evaluate post/thawed motility, viability, and membrane integrity. The experiment consists of three trials.

Results

At 8% glycerol concentration, FP1 has significantly (P > 0.05) the highest percentage motility (73.33%) compared to FPs 2, 3, and 4 (56.68, 50.00, and 23.33% respectively). At 10% glycerol, FP2 had the highest motility (48.33%) and HOST (64.00%). At 15% glycerol, FP4 (fast freezing) had the highest percentage motility (71.67%), viability (76.33%), and HOST (71.67%). At 8%, DMSO concentrations FP4 had the highest significant (P > 0.05) motility, viability, and HOST. Ten percent and 15% DMSO revealed no significant (P > 0.05) difference in most parameters among all the FPS. DMSO performed better than glycerol irrespective of concentrations in all FPS on most parameters evaluated.

Conclusions

Fast freezing performed better with 15% concentration of glycerol, while slow and fast freezing performed better with 10% and 15% DMSO concentrations, which implies that DMSO may serve as better cryoprotectant for poultry semen freezing irrespective of freezing protocols adopted.
Follow the money: how is medical school teaching funded?
Authors: O'Brien Aileen , Korszun Ania
Published: July 2020

Growing student numbers are producing greater demand for teaching, and resources allocated for education are being placed under increasing strain. The need for more student clinical placements and more clinician teaching time is expanding. Psychiatrists have successfully drawn attention to the importance of parity between mental and physical illness. We now have a responsibility to ensure enhanced opportunities to teach psychiatry to our medical students. This is set against a background of an increasing number of psychiatry consultants leaving the profession and an already stretched National Health Service environment. Many consultants contribute to teaching but do not have this activity included in their job plans. Although clinics and clinical meetings are inevitably slower when students are present, there is often no backfill provided. As outlined below, trusts receive substantial funding to cover costs related to the teaching of medical students, but most of us don't know what actually happens to this money. Here, we discuss how teaching is currently funded and make recommendations regarding improving accountability.
Fibroblast growth factor 10 is a negative regulator of postnatal neurogenesis in the mouse hypothalamus
Authors: Goodman Timothy , Nayar Stuart G. , Clare Shaun , Mikolajczak Marta , Rice Ritva , Mansour Suzanne , Bellusci Saverio , Hajihosseini Mohammad K.
Published: July 2020

New neurons are generated in the postnatal rodent hypothalamus, with a subset of tanycytes in the third ventricular (3V) wall serving as neural stem/progenitor cells. However, the precise stem cell niche organization, the intermediate steps and the endogenous regulators of postnatal hypothalamic neurogenesis remain elusive. Quantitative lineage-tracing in vivo revealed that conditional deletion of fibroblast growth factor 10 (Fgf10) from Fgf10-expressing β-tanycytes at postnatal days (P)4-5 results in the generation of significantly more parenchymal cells by P28, composed mostly of ventromedial and dorsomedial neurons and some glial cells, which persist into adulthood. A closer scrutiny in vivo and ex vivo revealed that the 3V wall is not static and is amenable to cell movements. Furthermore, normally β-tanycytes give rise to parenchymal cells via an intermediate population of α-tanycytes with transient amplifying cell characteristics. Loss of Fgf10 temporarily attenuates the amplification of β-tanycytes but also appears to delay the exit of their α-tanycyte descendants from the germinal 3V wall. Our findings suggest that transience of cells through the α-tanycyte domain is a key feature, and Fgf10 is a negative regulator of postnatal hypothalamic neurogenesis.
Disc-associated proteins mediate the unusual hyperstability of the ventral disc in Giardia lamblia
Authors: Nosala Christopher , Hagen Kari D. , Hilton Nicholas , Chase Tiffany M. , Jones Kelci , Loudermilk Rita , Nguyen Kristofer , Dawson Scott C.
Published: July 2020

Giardia lamblia, a widespread parasitic protozoan, attaches to the host gastrointestinal epithelium by using the ventral disc, a complex microtubule (MT) organelle. The ‘cup-like’ disc is formed by a spiral MT array that scaffolds numerous disc-associated proteins (DAPs) and higher-order protein complexes. In interphase, the disc is hyperstable and has limited MT dynamics; however, it remains unclear how DAPs confer these properties. To investigate mechanisms of hyperstability, we confirmed the disc-specific localization of over 50 new DAPs identified by using both a disc proteome and an ongoing GFP localization screen. DAPs localize to specific disc regions and many lack similarity to known proteins. By screening 14 CRISPRi-mediated DAP knockdown (KD) strains for defects in hyperstability and MT dynamics, we identified two strains – DAP5188KD and DAP6751KD –with discs that dissociate following high-salt fractionation. Discs in the DAP5188KD strain were also sensitive to treatment with the MT-polymerization inhibitor nocodazole. Thus, we confirm here that at least two of the 87 known DAPs confer hyperstable properties to the disc MTs, and we anticipate that other DAPs contribute to disc MT stability, nucleation and assembly.
Pseudohyphal growth in Saccharomyces cerevisiae involves protein kinase-regulated lipid flippases
Authors: Frøsig Merethe Mørch , Costa Sara Rute , Liesche Johannes , Østerberg Jeppe Thulin , Hanisch Susanne , Nintemann Sebastian , Sørensen Helle , Palmgren Michael , Pomorski Thomas Günther , López-Marqués Rosa L.
Published: July 2020

Lipid flippases of the P4 ATPase family establish phospholipid asymmetry in eukaryotic cell membranes and are involved in many essential cellular processes. The yeast Saccharomyces cerevisiae contains five P4 ATPases, among which Dnf3p is poorly characterized. Here, we demonstrate that Dnf3p is a flippase that catalyzes translocation of major glycerophospholipids, including phosphatidylserine, towards the cytosolic membrane leaflet. Deletion of the genes encoding Dnf3p and the distantly related P4 ATPases Dnf1p and Dnf2p results in yeast mutants with aberrant formation of pseudohyphae, suggesting that the Dnf1p–Dnf3p proteins have partly redundant functions in the control of this specialized form of polarized growth. Furthermore, as previously demonstrated for Dnf1 and Dnf2p, the phospholipid flipping activity of Dnf3p is positively regulated by flippase kinase 1 (Fpk1p) and Fpk2p. Phylogenetic analyses demonstrate that Dnf3p belongs to a subfamily of P4 ATPases specific for fungi and are likely to represent a hallmark of fungal evolution.
Water-Phase Synthesis of Ultrathin Au Nanowires with a Two-Dimensional Parallel Array Structure
Authors: Miyajima Naoya , Wang Yung-Chen , Nakagawa Makoto , Kurata Hiroki , Imura Yoshiro , Wang Ke-Hsuan , Kawai Takeshi
Published: July 2020

Ultrathin Au nanowires (NWs) with a diameter below 2 nm have attracted considerable attention as a promising one-dimensional nanomaterial. However, they are practically synthesized in organic solvents. Here, for the first time, we report the synthesis of ultrathin Au NWs with ∼1.7 nm diameter in water using a water-soluble long-chain amidoamine derivative (C18AA) as a key compound. The resultant Au NWs were naturally dispersible in water, which is an environment-friendly solvent. We also demonstrate that the formation of the Au NWs is based on oriented-attachment growth mechanism, and that the presence of Cl− ion facilitates its effective elongation over a length of a few µm. Further, cryogenic transmission electron microscopy (cryo-TEM) of the aqueous dispersion revealed that the Au NWs self-assembled into a bundle structure with two-dimensional parallel arrays in water.
microRNA-seq of cartilage reveals an overabundance of miR-140-3p which contains functional isomiRs
Authors: Woods Steven , Charlton Sarah , Cheung Kat , Hao Yao , Soul Jamie , Reynard Louise N. , Crowe Natalie , Swingler Tracey E. , Skelton Andrew J. , Piróg Katarzyna A. , Miles Colin G. , Tsompani Dimitra , Jackson Robert M. , Dalmay Tamas , Clark Ian M. , Barter Matt J. , Young David A.
Published: July 2020

miR-140 is selectively expressed in cartilage. Deletion of the entire Mir140 locus in mice results in growth retardation and early-onset osteoarthritis-like pathology; however, the relative contribution of miR-140-5p or miR-140-3p to the phenotype remains to be determined. An unbiased small RNA sequencing approach identified miR-140-3p as significantly more abundant (>10-fold) than miR-140-5p in human cartilage. Analysis of these data identified multiple miR-140-3p isomiRs differing from the miRBase annotation at both the 5′ and 3′ end, with >99% having one of two seed sequences (5′ bases 2–8). Canonical (miR-140-3p.2) and shifted (miR-140-3p.1) seed isomiRs were overexpressed in chondrocytes and transcriptomics performed to identify targets. miR-140-3p.1 and miR-140-3p.2 significantly down-regulated 694 and 238 genes, respectively, of which only 162 genes were commonly down-regulated. IsomiR targets were validated using 3′UTR luciferase assays. miR-140-3p.1 targets were enriched within up-regulated genes in rib chondrocytes of Mir140-null mice and within down-regulated genes during human chondrogenesis. Finally, through imputing the expression of miR-140 from the expression of the host gene WWP2 in 124 previously published data sets, an inverse correlation with miR-140-3p.1 predicted targets was identified. Together these data suggest the novel seed containing isomiR miR-140-3p.1 is more functional than original consensus miR-140-3p seed containing isomiR.
Customer Supercharging in Experience-Centric Channels
Authors: Bell David R. , Gallino Santiago , Moreno Antonio
Published: July 2020

We conjecture that for online retailers, experience-centric offline store formats do not simply expand market coverage, but rather, serve to significantly amplify future positive customer behaviors, both online and offline. We term this phenomenon “supercharging” and test our thesis using data from a digital-first men’s apparel retailer and a pioneer of the so-called zero inventory store (ZIS) format—a small-footprint, experience-centric retail location that carries no inventory for immediate fulfillment, but fulfils orders via e-commerce. Using a risk-set matching approach, we calibrate our estimates on customers who are “treated,” that is, have a ZIS experience, and matched with identical customers who shop online only. We find that after the ZIS experience, customers spend more, shop at a higher velocity, and are less likely to return items. The positive impact on returns is doubly virtuous as it is more pronounced for more tactile, higher-priced items, thus mitigating a key pain point of online retail. Furthermore, the ZIS shopping experience aids product discovery and brand attachment, causing sales to become more diffuse over a larger number of categories. Finally, we demonstrate that our results are robust to self-selection and potentially confounding effects of unobservable factors on the matched pairs of customers. Implications for retailing practice, including for legacy, offline-first retailers, are discussed.

This paper was accepted by Victor Martínez-de-Albéniz, operations management.
Relationship between World Assumptions and Resilience in Psychological Counsellors: The Mediating Role of Self-Orientations
Authors: Erden-Cinar Seval
Published: July 2020

The purpose of the study was to examine the mediating role of self-orientations in the relationship between resilience and world assumptions of psychological counsellors. A total of 321 psychological counsellors, were recruited and 211 of them were women and 110 of them were men.  The ages of the participants ranged from 23 to 52. The Brief Resilience Scale, World Assumptions Scale, and Balanced Integration-Differentiation (BID) Scale were used as data collection tools. In the analysis of the data, descriptive statistics, Pearson Correlation Coefficient, as well as the Bootstrap method was used to analyze the mediation effects. The findings showed that the assumptions of benevolence, randomness, self-worth, and justice and self-orientation were positively related to psychological resilience. Results of the mediation analysis revealed that self-developmental and interrelational orientations had mediation effects on relationships between world assumptions and resilience as in the proposed model. Findings for the model tested in the study were discussed with the literature and the implications were given to field experts, researchers, and psychological counsellors.
Analysis of Training Offers on Active Methodologies for University Teachers in Spain
Authors: Higueras-Rodriguez Lina , Garcia-Vita Maria del Mar , Medina-Garcia Marta
Published: July 2020

The current offer of training courses for university teachers is due, among other needs, to the implementation of an educational model based on student learning, promoting the use of active methodologies for their motivation and academic performance. An exploratory-descriptive and ideographic study is presented where the main technique is the analysis of content. To this end, 15 Spanish universities with the greatest prestige were analyzed according to the parameters of the Academic Ranking of World Universities (ARWU) in relation to the topics related to active methodologies and the profile of university teachers. The results show the different teacher training courses that have been carried out during the 2019/2020 academic year. We find that there are more universities that present more training of this type than others, and who this type of training is aimed at: new teachers and teachers with professional experience. The conclusions are related to the importance of the courses for the professional development of university teachers, since they should not be anchored in the same methodology, but should be open to new challenges and always taking into account the students, enhancing their motivation and academic performance.
A general method to obtain the spectrum and local spectra of a graph from its regular partitions
Authors: Dalfó Cristina , Fiol Miquel Àngel
Published: July 2020

It is well known that, in general, part of the spectrum of a graph can be obtained from the adjacency matrix of its quotient graph given by a regular partition. In this paper, a method that gives all the spectrum, and also the local spectra, of a graph from the quotient matrices of some of its regular partitions, is proposed. Moreover, from such partitions, the $C$-local multiplicities of any class of vertices $C$ is also determined, and some applications of these parameters in the characterization of completely regular codes and their inner distributions are described. As examples, it is shown how to find the eigenvalues and (local) multiplicities of walk-regular, distance-regular, and distance-biregular graphs.
Rifts, Ruptures, and Fractures: The (Ir)relevance of Postmodern Conceptual Frames from the Point of View of Palestine's Poet Mahmoud Darwish
Authors: Daragmeh AbdelKarim , Qabaha Ahmad
Published: July 2020

This article responds to the relative neglect of reading Mahmoud Darwish from a postmodern perspective. Inspired by postmodern theory, we suggest that Darwish after Oslo agreements in 1993 seeks to have a displaced and dialectical encounter with the collective identity; he utilizes a transition from being into becoming, from filiation into affiliation, knowing that this transition mirrors rifts, ruptures, and fractures in the Palestinian historical and geopolitical conditions in the post-Oslo era. By looking at poems written after the Oslo Accords, which were described by Bashir Abu-Manneh as “the root cause of the disintegration and liquidation of Palestinian agency,” we argue that Darwish's persona manifests the postmodern intellectual who is tempted to leave the collective and expatriate himself to hone an independent self and thought that provides a fresh perspective and a new understanding of Palestinian collectivity. While Darwish's pre-Oslo poetry expressed a collective voice, identification, and commitment to the national narrative, after Oslo, he gets more personal and, perhaps, detached from and critical of the nationalist political entities and narratives. Building on theoretical insights from both postcolonial and postmodern intellectuals, we also articulate ways in which the dialectical relation between postcolonialism and postmodernism appears in Darwish's poetry. We find that the persona at times combines, and at other times, fluctuates between, singularity and multiplicity, certainty and suspicion, the collective and the personal, place and space, tradition and innovation, while seeking revision, transition, contingency, dynamism, fluidity in the contemporary, post-Oslo time.
Making Shiʿism an Indian Religion: A Perspective from the Qutb Shahi
Deccan
Authors: Ruffle Karen
Published: July 2020

Engaging an ethnohistorical approach, this essay examines how the Qutb Shahi
sultans represented themselves locally and regionally through the use of built
space, sponsorship of ritual and innovation of material practices that enabled
diverse constituents of the realm to participate in and remember the martyrdom
of the third Shi'i Imam Husain at the battle of Karbala, Iraq in 680 CE in ways
that made Shiʿism an Indian religion. I use a case study engaging material
culture and built space in imperial Hyderabad to demonstrate how the Qutb Shahi
sultans became Deccani, using Shiʿism as both an expression of their identity
and a polyvalent religio-cultural mediation with the Hindu majority communities
over which they ruled. The essay examines the Charminar of the fifth sultan
Muhammad Quli Qutb Shah (r. 1580–1612), the monumental gateway to the new city
of Hyderabad, as a polyvalent symbol of their status as Shi'i upholders of
dharmic kingship.
Beyond the ‘salary institution’: on the ‘society of performance’ and the platformisation of the employment relationship
Authors: Chicchi Federico
Published: July 2020

In this contribution the author discusses the intimate relationship between the crisis of the wage labour system of industrial capitalism and the growing diffusion of spaces of exploitation related to the explosion of digital algorithms and platforms. In other words, it is argued that capitalist transformation (in the post-Fordist sense) has had a decisive impact on the social relationship of subordination by inscribing the practices of exploitation of labour into an extended space that the traditional category of subsumption was not able to describe effectively. Even more specifically, work in contemporary society - a society where the digital paradigm takes on an unprecedented configuration through the platformisation of capital-work relationships - is forced to redefine itself as a mere performance, where performance means an activity that is basically stripped from the social protections of paid employment and is legitimised on a social level only by virtue of its immediate commercial usability. In other words, work in the society of performance is a subjective space deprived of the (formal and substantial) protective dimensions that were specified during what is sometimes referred to as the wage-earning society. At the same time, work is also a space subjected to an extraction of value according to a precise and renewed neoliberal logic that finds in the new urban fabric a place to renew its social hegemony.
Devaluation of cultural capital on online platforms and the changing shape of the social space
Authors: Höhne Thomas , Sproll Martina
Published: July 2020

This article analyses the devaluation of work and qualifications on crowdworking platforms. It argues that - in the context of a digital reputation economy - cultural capital (formal and incorporated standards of skills and knowledge) is increasingly being devalued, informalised and replaced by symbolic capital. We argue that these changes impact on social relations and the social space. The devaluation and precariousness of crowdwork does not only reflect a crisis of social reproduction and increasing socio-economic inequalities, but also changes traditional channels of upward mobility and thus the structuring of the social space. Furthermore, increasing individual competition implies gendered and discriminatory dynamics.
Roadmap to free space optics
Authors: Trichili Abderrahmen , Cox Mitchell A. , Ooi Boon S. , Alouini Mohamed-Slim
Published: July 2020

With the ever-increasing demand for data and the radio frequency spectrum becoming congested, free space optics (FSO) may find a niche for situations where fiber is too expensive or too difficult to install. FSO is a cross-disciplinary field that draws from radio and fiber communication, astronomy, and even quantum optics, and it has seen major advances over the last three decades. In this tutorial-style review, we provide a broad overview of many of the important topics required to design, develop, and research the next generation of FSO technology.
Tri-layer gradient and polarization-selective vertical couplers for interlayer transition
Authors: Bai Ningfeng , Zhu Xiaotao , Zhu Yijun , Hong Wei , Sun Xiaohan
Published: July 2020

We demonstrate and optimize a tri-layer vertical coupler for a silicon nitride (Si3N4) multilayer platform operating at a 2 µm band. The large spacing between the topmost and bottommost layers of a gradient structure enables ultra-low crossing loss and interlayer crosstalk without affecting the efficiency interlayer transition. We achieve a 0.31 dB transition loss, ultra-low multi-layer crosstalk of -59.3 dB at a crossing angle of 90° with an interlayer gap of 2300 nm at 1950nm. With width optimization of this structure, the fabrication tolerances toward lateral misalignment of two stages in this coupler have increased 61% and 56%, respectively. We also propose a vertical coupler, based on this design, with mode selectivity and achieve an extinction ratio of < 15 dB for wavelengths in the 1910-1990 range. Meanwhile, a multi-layer interlaced AWGs centered at 1950nm and based on vertical coupler has been demonstrated. The proposed vertical couplers exhibit potential for application in large-scale photonic-integrated circuits and broadly in photonic devices.
Single-pixel compressive optical image hiding based on conditional generative adversarial network
Authors: Li Jiaosheng , Li Yuhui , Li Ju , Zhang Qinnan , Li Jun
Published: July 2020

We present a deep learning (DL) framework based on a conditional generative adversarial network (CGAN) to perform compressive optical image hiding (COIH) with a single-pixel detector. An end-to-end compressive sensing generative adversarial network (eCSGAN) is developed, achieving the approximate equivalent model of an inverse system of a nonlinear COIH model, to reconstruct two-dimensional secret images directly from real acquired one-dimensional compressive sampling signals without the need of any security keys of the COIH system such as the sequence of illumination patterns, the host image, etc. Moreover, detailed comparisons between the image reconstructed using eCSGAN and compressive sensing (CS) shows that the proposed method can remarkably increase the quality in image reconstruction with a lower sampling rate. The feasibility and security of the proposed method are demonstrated by the numerical simulations and optical experiment results.
Wear measurement based on the length variation of a sacrificial FBG
Authors: Zeng Fanhao , Li Zhengying , Gui Xin , Fu Xuelei , Wang Honghai
Published: July 2020

A high-precision wear measurement method with temperature stability achieved by measuring the length variation of a fiber Bragg grating (FBG) is proposed. The adoption of the optical frequency-domain reflectometry (OFDR) technology makes the spatial resolution of this measurement method reach 15.13 µm, and the offline and online measurement accuracies are 30 µm and 100 µm, respectively. The systematic error of the FBG length measuring system is within 30 µm. Because the length measurement is done with a short FBG instead of a much longer fiber, the measurement error induced by the time-varying temperature or strain is significantly reduced in the proposed method. The spatial resolution and accuracy of this method is suitable for wear measurements of various parts in the mechanical field, such as bearings, gears, and pistons.
Low-coherence digital holography with a multireflection reference mirror
Authors: Pham Quang Duc , Hayasaki Yoshio
Published: July 2020

A method for expanding the measurement range of low-coherence digital holography up to several times longer than the coherence length is proposed. The method was implemented with a multireflection reference mirror composed of partially and highly reflective mirrors, in conjunction with the Fourier transform method with spatial filtering for single-shot complex amplitude imaging, making it useful for observing a moving and deforming object. One of the features of the reference arm is that the measurement range is simply controlled by adjusting the position and angle of the highly reflective mirror. The measurement of objects with a general curved shape and a large step height was demonstrated.
8 × 8 SOA-based optical switch with zero fiber-to-fiber insertion loss
Authors: Mojaver Hassan Rahbardar , Tolstikhin Valery , Gargallo Bernardo , Baños Rocio , Domenech David , Lo Jessica , Kumar Dhiraj , Leong Kin-Wai , Liboiron-Ladouceur Odile
Published: July 2020

The design, fabrication, and characterization of an

8

×

8

lossless optical switch, based on semiconductor optical amplifier (SOA) gates, is reported. It comprises three stages of

2

×

2

switches into an

8

×

8

Banyan switch, for a total of 48 SOAs. Three SOAs on each optical path provide gain to compensate for on-chip and fiber coupling loss, thereby making the optical switch lossless. All 64 optical paths demonstrate error-free 10 Gbps NRZ PRBS-31 transmission with at least 30 dB signal-to-noise ratio and less than 0.9 dB power penalty.
High sensitivity demodulation of a reflective interferometer-based optical current sensor using an optoelectronic oscillator
Authors: Wang Muguang , Zhang Naihan , Huang Xiaodi , Yin Bin , Mu Hongqian , Han Mengyao , Chen Desheng
Published: July 2020

A novel, to the best of our knowledge, interrogation scheme based on an optoelectronic oscillator (OEO) with high sensitivity and high speed response for a fiber optical current sensor utilizing a reflective interferometer is proposed and experimentally demonstrated. Due to the Faraday effect, a magneto-optic phase shift induced by current variation is generated between two orthogonal light waves. The polarization-dependent properties of the Mach–Zehnder modulator are used to convert the magneto-optic phase shift into the phase difference between the optical carrier and sideband, which is then mapped to the oscillating frequency shift by closing an OEO loop. A high current sensitivity of 152.5 kHz/A with a range of 0–2.5 A is obtained in the experiment.
Structure of cytotoxic associated antigen A protein of Helicobacter pylori from Bali and Lombok isolates of Indonesia
Authors: Suharsono Hamong , Wibawa Dewa Nyoman , Muttaqin Zainul , Agustina Kadek Karang
Published: July 2020

Background and Aim: Helicobacter pylori is a well-known zoonotic agent with worldwide distribution. In Indonesia, only one report regarding the variation within the cytotoxic associated antigen A (CagA) protein of H. pylori has been described in the literature, which was conducted in Manado, South Sulawesi. There remains no report concerning the structure of this protein, particularly for the Bali and Lombok isolates. The objective of this study was to investigate the diversity of H. pylori CagA amino acid sequences of Bali and Lombok isolates, to predict their molecular structures and conduct toxicity examination of CagA on gastric cells.

Materials and Methods: A total of 36 samples were used in equal proportions for each pathologic condition. DNA extraction was performed to subculture H. pylori Bali isolates. The amplification of the CagA 3' variable region was carried out using the primers P1 (5'-GATAACAGGCAAGCTTTTTGAGG-3') and P2 (5'-CTGCAAAAGATTGTTTGGCAG-3'). The W2, W9, and W35 fragments were selected as a representation of H. pylori Bali isolates, which were modeled through the threading modeling approach using I-TASSER.

Results: According to the 12 CagA sequences obtained and phylogenetic analyses, the H. pylori strain originating from Bali can be grouped within the East Asian genotypes and is identical to the Lombok strain. In addition, the Bali isolates are phylogenetically more closely related to Southeast Asian strains, particularly the Filipino strain. The relationship between degree of inflammation induced and CagA-positive infection was not statistically significant.

Conclusion: The structure of the H. pylori Bali isolate is identical to that of Lombok isolate, which belongs to the same group of East Asian genotypes, and bacterial virulence is not related to structure.
Funkcionális variáció és átmenetiség a határozói igenevek köréből
Authors: Varga Mónika
Published: July 2020

A dolgozat a határozói igeneves és az igével konstruált szerkezetek variációjának egy olyan, eddig kevéssé tárgyalt esetével foglalkozik, amikor az értelmező/specifikáló olvasat mellé a cselekvés/történés módjára épülő következményesség kifejezése kapcsolódik. Az elemzés célja a szerkezeti és használati jellemzők bemutatása, elsősorban korpuszadatokon keresztül. A tagmondatok közötti viszony itt javasolt meghatározása részben eltávolodik az igenevekre vonatkozó hagyományos funkció-meghatározástól, hangsúlyozva az oksági viszonyok, elsősorban a következményes jelentéstartalom és következtető viszony összetett, kontextusfüggő természetét az igeneves tagmondatok esetében is. A szerkezetek grammatikai és pragmatikai leírása az igés konstruálással megfeleltetve történik, beleértve az igeneves szerkezetet tartalmazó tagmondat beágyazott vs. független jellegének vizsgálatát is.
PAX6: a transcriptional guardian for glutamatergic fate in the developing neocortex
Authors: Tan Kai Boon , Kozic Zrinko , Dobolyi Dániel , Manuel Martine , Mason John , Price David
Published: July 2020

During forebrain development, the transcription factor PAX6 is highly expressed by progenitors in the dorsal telencephalon (dTel) i.e. the primitive cerebral cortex with a sharp boundary at the pallial-subpallial boundary, thereby establishing the dorso-ventral patterning of the forebrain and regulating the generation of cortical glutamatergic neurons. Strikingly, removal of
Pax6led to a diversion away from the glutamatergic identity in a subset of cortical progenitors indicated by ectopic gene expression. We postulate that PAX6 confers glutamatergic fate in progenitors by preventing them from responding to signaling cues such as SHH that can induce abberant fates. In the present study, we used the transgenic mouse model with
Pax6conditionally deleted in the cortex using a tamoxifen-inducible
Emx1-CreER
T2
transgene combined with a floxed
Pax6and an EGFP constructs. Single-cell transcriptome revealed multiple ectopic leanages in cortical progenitors with morphogen-regulated transcriptional signatures upon
Pax6deletion. We also undertook a candidate approach to investigate how attenuation of signaling cues by surgical and pharmacological means using
in vitroslice culture affect the magnitude of ectopic gene expression in the cortical progenitors. We demonstrated that attenuation of interneuron migration into the cortex and inhibition of SHH signaling pathway in slice culture substatially reduced aberrant gene expression in the cortical progenitors. Our findings suggest that ventral cues from vTel such as SHH possess ventralizing effect on cortical progenitors, this is consistent with a requirement for PAX6 to resist such effects in order to safeguard glutamatergic fate.
Mitochondrial Dynamics: impact on adult neural stem cell fate
Authors: Soares Rita , Lourenço Diogo M. , Verduyckt Jonathan , Sebastião Ana M. , Xapelli Sara , Morais Vanessa A.
Published: July 2020

Neural stem cells (NSCs) are found in discrete regions of the mammalian brain. During adulthood, NSCs can be a source of new neurons and oligodendrocytes in neurological disorders. However, these newborn cells are not sufficient to overcome the neurological deficits involved by neural loss. Therefore, the identification of novel mechanisms responsible for modulating NSC fate represent a major key issue for future brain repair strategies. Several studies suggest that mitochondria have an important role in regulating NSC differentiation and lineage determination. However, the molecular mechanisms involved in this regulation remain unknown. Hence, our work aims to dissect how mitochondria biogenesis and dynamics can modulate the NSC differentiation into neurons or oligodendrocytes. For this, NSCs were obtained by isolating subventricular zone (SVZ) and dentate gyrus (DG) cells from P1-3 mouse models. Seeding density, culture conditions and number of passages were determined. Moreover, the multipotency of SVZ/DG-derived NSPCs, obtained from different passages, was also accessed. Additionally, expression of proteins involved in mitochondrial biogenesis and fusion/fission appear altered during NSPC differentiation, while mitochondrial network revealed different morphologies in cells from different lineages. The results obtained will provide novel findings concerning the role of mitochondrial dynamics in NSC fate.