bluuebunny/crossref_metadata_2025 huggingface dataset:
Hippocampal granule cell dispersion: a non-specific finding in pediatric patients with no history of seizures
Authors: Roy Achira , Millen Kathleen J. , Kapur Raj P.
Published: April 2020

Chronic epilepsy has been associated with hippocampal abnormalities like neuronal loss, gliosis and granule cell dispersion. The granule cell layer of a normal human hippocampal dentate gyrus is traditionally regarded as a compact neuron-dense layer. Histopathological studies of surgically resected or autopsied hippocampal samples primarily from temporal lobe epilepsy patients, as well as animal models of epilepsy, describe variable patterns of granule cell dispersion including focal cell clusters, broader thick segments, and bilamination or “tram-tracking”. Although most studies have implicated granule cell dispersion as a specific feature of chronic epilepsy, very few “non-seizure” controls were included in these published investigations. Our retrospective survey of 147 cadaveric pediatric human hippocampi identified identical morphological spectra of granule cell dispersion in both normal and seizure-affected brains. Moreover, sections across the entire antero-posterior axis of a control cadaveric hippocampus revealed repetitive occurrence of different morphologies of the granule cell layer – compact, focally disaggregated and bilaminar. The results indicate that granule cell dispersion is within the spectrum of normal variation and not unique to patients with epilepsy. We speculate that sampling bias has been responsible for an erroneous dogma, which we hope to rectify with this investigation.
The synergistic effect of an imidazolium salt and benzotriazole on the protection of bronze surfaces with chitosan-based coatings
Authors: Silva da Conceição Debora Kelen , Nunes de Almeida Kauana , Nhuch Elsa , Raucci Maria Grazia , Santillo Chiara , Salzano de Luna Martina , Ambrosio Luigi , Lavorgna Marino , Giuliani Chiara , Di Carlo Gabriella , Staccioli Maria Paola , Falcade Tiago , Schrekker Henri Stephan
Published: April 2020

The class of imidazolium salts contains effective anticorrosion additives for metal substrates. This study evaluated the potential of 1-carboxymethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (HO

2

CC

1

MImNTf

2
) for application in cultural heritage, exploring it as anticorrosion additive in chitosan-based coatings for the protection of copper-based alloys. Under accelerated corrosion conditions with HCl vapor, the chitosan coating with HO

2

CC

1

MImNTf

2
was less effective than the one with benzotriazole. The coating with a combination of HO

2

CC

1

MImNTf

2
and benzotriazole resulted in the optimal protective efficacy of the bronze surface, and it also maintained high transparency without changing the bronze appearance.
Efficacy and safety of elobixibat in hemodialysis patients with chronic constipation: a retrospective study
Authors: Shono Takefumi , Hyakutake Hiroyuki
Published: April 2020

Background

Hemodialysis patients are likely to develop constipation as a complication due to food and fluid restrictions. Elobixibat is a new laxative that inhibits the ileal bile acid transporter expressed in the terminal ileum, suppresses bile acid reabsorption, increases the amount of bile acid flowing into the colon lumen, and promotes water secretion in the colon and colon motility. In this study, we examined the efficacy and safety of elobixibat in maintenance hemodialysis patients with chronic constipation.

Methods

In a study conducted on maintenance hemodialysis patients with chronic constipation, comparisons were conducted retrospectively based on constipation symptoms such as the frequency of spontaneous bowel movements before elobixibat treatment and 12 weeks after the administration of elobixibat, as well as based on blood electrolyte levels.

Results

The study was conducted on 23 patients, 19 of whom were subjected to treatment efficacy analysis. The frequency of spontaneous bowel movements was 2.0 ± 0.7 times/week before administration of elobixibat and reached 4.9 ± 2.3 times/week after 12 weeks of administration. The increase started after 1 week of treatment. Elobixibat treatment improved the constipation score (baseline, 10.4 ± 3.2; after 12 weeks, 5.7 ± 3.2), the Bristol Stool Form Scale (baseline, 2.2 ± 1.0; after 12 weeks, 4.2 ± 0.7), and patient satisfaction regarding defecation (baseline, 2.9 ± 0.9; after 12 weeks, 1.7 ± 1.1). The interdialytic weight gain (IDWG) was 5.68 ± 0.82% before initiation of treatment and decreased to 4.54 ± 1.34% after 12 weeks. The serum inorganic phosphorus (IP) levels were 5.68 ± 1.25 mg/dL and decreased to 4.93 ± 1.10 mg/dL after 12 weeks.

Conclusions

Elobixibat was effective in improving constipation symptoms in maintenance hemodialysis patients with chronic constipation. Elobixibat also improved dialysis-related laboratory test results, such as a decrease in serum IP levels and IDWG.

Trial registration

UMIN Clinical Trials Registry,UMIN000037285, retrospectively registered
Ohio physician attitudes toward medical Cannabis and Ohio’s medical marijuana program
Authors: Lombardi Emilia , Gunter Joshua , Tanner Erin
Published: April 2020

Background

Ohio’s medical cannabis program is one of three states that require physicians to become certified to recommend medical cannabis to their patients. The current study examines the attitudes of Ohio physicians toward medical cannabis and Ohio’s program to ascertain how likely physicians are to participate in Ohio’s program.

Methods

Physicians were invited to complete an internet survey that asked them about their concerns regarding medical marijuana, Ohio’s program, their likelihood of recommending medical cannabis, and becoming certified within the state. Ordinal and logistic regressions were used to understand the physicians’ likelihood of recommending cannabis, of becoming certified to recommend cannabis, and their attitude toward Ohio’s program.

Results

In total, 11,665 physicians licensed to practice in Ohio were contacted by email, and 344 responses were received for a response rate of 2.9%. Only 42 physicians reported being certified or had plans to become certified to recommend marijuana, and 62% were unlikely to recommend marijuana to their patients. Overall, the belief that medical cannabis should be legal had the greatest association with the likelihood of recommending cannabis (OR = .37, 95% CI = .24–.54), of becoming certified (OR = .21, 95% CI = .10–.38), and believing that Ohio’s program is too strict (OR = .39, 95% CI = .30–.51). However, the study sample precludes generalizing the results beyond this study. The 2.9% response rate could indicate a bias toward physicians who have strong opinions about the legality of medical cannabis.

Conclusion

The results show that many physicians have concerns about medical cannabis and Ohio’s program, and many physicians may not participate in the program. This could be a problem for patients who would like to use cannabis for medical reasons; therefore, these patients, may need to utilize one physician for cannabis and another for regular care. Physicians will likely be caring for patients who are using cannabis regardless of their own beliefs about it. The lack of training regarding cannabis in healthcare, along with requiring “certified recommenders” to have training could result in a fractured healthcare system.
Colorectal Cancer in the Young: Epidemiology, Prevention, Management
Authors: Siegel Rebecca L. , Jakubowski Christopher Dennis , Fedewa Stacey A. , Davis Anjee , Azad Nilofer S.
Published: April 2020

Colorectal cancer (CRC) incidence rates in the United States overall have declined since the mid-1980s because of changing patterns in risk factors (e.g., decreased smoking) and increases in screening. However, this progress is increasingly confined to older adults. CRC occurrence has been on the rise in patients younger than age 50, often referred to as early-onset disease, since the mid-1990s. Young patients are more often diagnosed at an advanced stage and with rectal disease than their older counterparts, and they have numerous other unique challenges across the cancer management continuum. For example, young patients are less likely than older patients to have a usual source of health care; often need a more complex treatment protocol to preserve fertility and sexual function; are at higher risk of long-term and late effects, including subsequent primary malignancies; and more often suffer medical financial hardship. Diagnosis is often delayed because of provider- and patient-related factors, and clinicians must have a high index of suspicion if young patients present with rectal bleeding or changes in bowel habits. Educating primary care providers and the larger population on the increasing incidence and characteristic symptoms is paramount. Morbidity can further be averted by increasing awareness of the criteria for early screening, which include a family history of CRC or polyps and a genetic predisposition.
Breast Cancer in Young Women Presents With More Aggressive Pathologic Characteristics: Retrospective Analysis From an Argentine National Database
Authors: Fabiano Verónica , Mandó Pablo , Rizzo Manglio , Ponce Carolina , Coló Federico , Loza Martín , Loza Jose , Amat Mora , Mysler Daniel , Costanzo María Victoria , Nervo Adrián , Nadal Jorge , Perazzo Florencia , Chacón Reinaldo ,   on behalf of RCM Database Contributors
Published: April 2020

PURPOSE

Multiple studies have reported that breast cancer in young patients is associated with aggressive characteristics, and it is suggested that prognosis is worse independently of pathologic variables.

PATIENTS AND METHODS

We performed a retrospective analysis of the Breast Cancer Registry of the Argentinian Society of Mastology, including public and private centers. Patients ≤ 40 years of age at diagnosis were classified as “young,” and patients ≤ 35 years of age at diagnosis were classified as “very young.” Univariate and multivariate analyses were performed to detect differences between groups.

RESULTS

Patients ≤ 40 years of age comprised 10.40% (739/7,105) of the participants, with an average age of 35.61 ± 4.04 years. Multivariate analysis showed that human epidermal growth factor receptor 2 (HER2)-positive tumor phenotype (odds ratio [OR], 1.82), nodal involvement (OR, 1.69), histologic grade (grade 3 OR, 1.41), and tumor size (T2 OR, 1.37; T3-T4, 1.47) were independently associated with younger age at diagnosis. Patients ≤ 35 years of age (n = 286), compared with patients 36 to 40 years of age, had a higher proportion of HER2 tumors (24.58% v 16.94%; P = .021), absence of progesterone receptor expression (29.85% v 22.95%; P = .043), and stage 3 cancer (29.34% v 18.52%; P < .001). Fewer breast-conserving surgeries (75.37% v 62.89%; P < .001) and more adjuvant chemotherapy (59.04% v 36.66%; P < 0.001) were reported in patients ≤ 40 years of age.

CONCLUSION

In the population studied, breast cancer in young women was associated with aggressive pathologic features and locally advanced disease at the time of diagnosis. Moreover, tumor characteristics in very young patients with breast cancer nested in the population ≤ 40 years of age showed differences in important prognostic factors. More high-quality evidence is needed to improve treatment strategies in these patients.
A Case Series of Patients with Isolated IgG4-related Hypophysitis Treated with Rituximab
Authors: Boharoon Hessa , Tomlinson James , Limback-Stanic Clara , Gontsorova Anastasia , Martin Niamh , Hatfield Emma , Meeran Karim , Nair Ramesh , Mendoza Nigel , Levy Jeremy , McAdoo Steve , Pusey Charles , Wernig Florian
Published: April 2020

Context

The acute presentation of immunoglobulin G4 (IgG4)-related hypophysitis can be indistinguishable from other forms of acute hypophysitis, and histology remains the diagnostic gold standard. The high recurrence rate necessitates long-term immunosuppressive therapy. Rituximab (RTX) has been shown to be effective in systemic IgG4-related disease (IgG4-RD), but experience with isolated pituitary involvement remains limited.

Case Description

We report 3 female patients with MRI findings suggestive of hypophysitis. All patients underwent transsphenoidal biopsy and fulfilled diagnostic criteria for IgG4-related hypophysitis. Treatment with glucocorticoids (GCs) resulted in good therapeutic response in Patients 1 and 2, but the disease recurred on tapering doses of GCs. GC treatment led to emotional lability in Patient 3, necessitating a dose reduction. All 3 patients received RTX and Patients 2 and 3 received further courses of treatment when symptoms returned and B-cells repopulated. Patient 3 did not receive RTX until 12 months from the onset of symptoms. Patient 1 was not able to have further RTX treatments due to an allergic reaction when receiving the second dose. Rituximab treatment resulted in sustained remission and full recovery of anterior pituitary function in Patients 1 and 2, with complete resolution of pituitary enlargement. By contrast, Patient 3 only showed a symptomatic response following RTX treatment, but pituitary enlargement and hypofunction persisted.

Conclusion

Rituximab treatment for IgG4-related hypophysitis resulted in sustained remission in 2 patients treated early in the disease process but only achieved partial response in a patient with chronic disease, suggesting that early therapeutic intervention may be crucial in order to avoid irreversible changes.
Translesion synthesis polymerases contribute to meiotic chromosome segregation and cohesin dynamics in S
chizosaccharomyces pombe
Authors: Mastro Tara L. , Tripathi Vishnu P. , Forsburg Susan L.
Published: April 2020

Translesion synthesis polymerases (TLSPs) are non-essential error-prone enzymes that ensure cell survival by facilitating DNA replication in the presence of DNA damage. In addition to their role in bypassing lesions, TLSPs have been implicated in meiotic double-strand break repair in several systems. Here, we examine the joint contribution of four TLSPs to meiotic progression in the fission yeast Schizosaccharomyces pombe. We observed a dramatic loss of spore viability in fission yeast lacking all four TLSPs, which is accompanied by disruptions in chromosome segregation during meiosis I and II. Rec8 cohesin dynamics are altered in the absence of the TLSPs. These data suggest that the TLSPs contribute to multiple aspects of meiotic chromosome dynamics.
The PRR14 heterochromatin tether encodes modular domains that mediate and regulate nuclear lamina targeting
Authors: Dunlevy Kelly L. , Medvedeva Valentina , Wilson Jade E. , Hoque Mohammed , Pellegrin Trinity , Maynard Adam , Kremp Madison M. , Wasserman Jason S. , Poleshko Andrey , Katz Richard A.
Published: April 2020

A large fraction of epigenetically silent heterochromatin is anchored to the nuclear periphery via ‘tethering proteins’ that function to bridge heterochromatin and the nuclear membrane or nuclear lamina. We previously identified a human tethering protein, PRR14, that binds heterochromatin through an N-terminal domain, but the mechanism and regulation of nuclear lamina association remained to be investigated. Here we identify an evolutionarily conserved PRR14 nuclear lamina binding domain (LBD) that is both necessary and sufficient for positioning of PRR14 at the nuclear lamina. We show that PRR14 associates dynamically with the nuclear lamina, and provide evidence that such dynamics are regulated through phosphorylation and dephosphorylation of the LBD. Furthermore, we identify a PP2A phosphatase recognition motif within the evolutionarily conserved C-terminal Tantalus domain of PRR14. Disruption of this motif affects PRR14 localization to the nuclear lamina. The overall findings demonstrate a heterochromatin anchoring mechanism whereby the PRR14 tether simultaneously binds heterochromatin and the nuclear lamina through two separable modular domains. Our findings also describe an optimal PRR14 LBD fragment that could be used for efficient targeting of fusion proteins to the nuclear lamina.
Compartmentalization of adenosine metabolism in cancer cells and its modulation during acute hypoxia
Authors: Losenkova Karolina , Zuccarini Mariachiara , Karikoski Marika , Laurila Juha , Boison Detlev , Jalkanen Sirpa , Yegutkin Gennady G.
Published: April 2020

Extracellular adenosine mediates diverse anti-inflammatory, angiogenic and vasoactive effects, and has become an important therapeutic target for cancer, which has been translated into clinical trials. This study was designed to comprehensively assess adenosine metabolism in prostate and breast cancer cells. We identified cellular adenosine turnover as a complex cascade, comprising (1) the ectoenzymatic breakdown of ATP via sequential ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1, officially known as ENPP1), ecto-5′-nucleotidase (CD73, also known as NT5E), and adenosine deaminase reactions, and ATP re-synthesis through a counteracting adenylate kinase and members of the nucleoside diphosphate kinase (NDPK, also known as NME/NM23) family; (2) the uptake of nucleotide-derived adenosine via equilibrative nucleoside transporters; and (3) the intracellular adenosine phosphorylation into ATP by adenosine kinase and other nucleotide kinases. The exposure of cancer cells to 1% O2 for 24 h triggered an ∼2-fold upregulation of CD73, without affecting nucleoside transporters, adenosine kinase activity and cellular ATP content. The ability of adenosine to inhibit the tumor-initiating potential of breast cancer cells via a receptor-independent mechanism was confirmed in vivo using a xenograft mouse model. The existence of redundant pathways controlling extracellular and intracellular adenosine provides a sufficient justification for reexamination of the current concepts of cellular purine homeostasis and signaling in cancer.

This article has an associated First Person interview with the first author of the paper.
A comparative study of post-operative endophthalmitis between immediate versus delayed management of eventful cataract extraction
Authors: Loya Hina , Ghoghari Hunain Razzak , Rizvi Syed Fawad
Published: April 2020

Objective: To compare the incidence of postoperative endophthalmitis after eventful cataract surgery i.e. posterior capsular rupture, in patients managed with anterior vitrectomy and intra ocular lens implantation intraoperatively to patients managed with anterior vitrectomy and intraocular lens implantation two weeks after the posterior capsule rupture.

Methods: This comparative study was conducted at Layton Rahamatullah Benevolent Trust, Free Base Eye Hospital Korangi, Karachi from February 2017 to December 2018. The study included two groups, group A had patients with intra ocular lens implanted after posterior capsule rupture intraoperatively, while Group B had patients with intra ocular lens implanted after two weeks of initial surgery. Incidence rate of post-operative endophthalmitis was compared between two groups, which happened within six weeks after intra ocular lens implantation surgery.

Results: Total number of cataract surgeries that were performed during the study was 37,969. Incidence of postoperative endophthalmitis was 0.0019%. The study enrolled patients with complicated cataract surgeries that were 3508 (0.09%). Out of which incidence of post-operative endophthalmitis that occurred in group A was 0.007% and group B was 0.002%. (p value <0.05). The study also found that complicated extracapsular cataract extraction with intraocular lens implantation had more cases of endophthalmitis compared to phacoemulsification with intraocular lens.

Conclusion: This study showed that management of posterior capsular rupture through anterior vitrectomy and secondary intraocular lens implantation after two weeks has less chances of postoperative endophthalmitis.

doi: https://doi.org/10.12669/pjms.36.4.1911

How to cite this:Loya H, Ghoghari HR, Rizvi SF. A comparative study of post-operative endophthalmitis between immediate versus delayed management of eventful cataract extraction. Pak J Med Sci. 2020;36(4):689-692. doi: https://doi.org/10.12669/pjms.36.4.1911

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Analysis of CDKN1C in fetal growth restriction and pregnancy loss
Authors: Suntharalingham Jenifer P. , Ishida Miho , Buonocore Federica , del Valle Ignacio , Solanky Nita , Demetriou Charalambos , Regan Lesley , Moore Gudrun E. , Achermann John C.
Published: April 2020

Background: Cyclin-dependent kinase inhibitor 1C (CDKN1C) is a key negative regulator of cell growth encoded by a paternally imprinted/maternally expressed gene in humans. Loss-of-function variants in CDKN1C are associated with an overgrowth condition (Beckwith-Wiedemann Syndrome) whereas “gain-of-function” variants in CDKN1C that increase protein stability cause growth restriction as part of IMAGe syndrome ( Intrauterine growth restriction, Metaphyseal dysplasia, Adrenal hypoplasia and Genital anomalies). As three families have been reported with CDKN1C mutations who have fetal growth restriction (FGR)/Silver-Russell syndrome (SRS) without adrenal insufficiency, we investigated whether pathogenic variants in CDKN1C could be associated with isolated growth restriction or recurrent loss of pregnancy.

Methods: Analysis of published literature was undertaken to review the localisation of variants in CDKN1C associated with IMAGe syndrome or fetal growth restriction. CDKN1C expression in different tissues was analysed in available RNA-Seq data (Human Protein Atlas). Targeted sequencing was used to investigate the critical region of CDKN1C for potential pathogenic variants in SRS (n=66), FGR (n=37), DNA from spontaneous loss of pregnancy (n= 22) and women with recurrent miscarriages (n=78) (total n=203).

Results: All published single nucleotide variants associated with IMAGe syndrome are located in a highly-conserved “hot-spot” within the PCNA-binding domain of CDKN1C between codons 272-279. Variants associated with familial growth restriction but normal adrenal function currently affect codons 279 and 281. CDKN1C is highly expressed in the placenta compared to adult tissues, which may contribute to the FGR phenotype and supports a role in pregnancy maintenance. In the patient cohorts studied no pathogenic variants were identified in the PCNA-binding domain of CDKN1C.

Conclusion: CDKN1C is a key negative regulator of growth. Variants in a very localised “hot-spot” cause growth restriction, with or without adrenal insufficiency. However, pathogenic variants in this region are not a common cause of isolated fetal growth restriction phenotypes or loss-of-pregnancy/recurrent miscarriages.
Staphylococcus aureus nasal carriage and microbiome composition among medical students from Colombia: a cross-sectional study
Authors: Reyes Niradiz , Montes Oscar , Figueroa Stephanie , Tiwari Raj , Sollecito Christopher C. , Emmerich Rebecca , Usyk Mykhaylo , Geliebter Jan , Burk Robert D.
Published: April 2020

Background: The anterior nares are the main ecological niche for Staphylococcus aureus, an important commensal and opportunistic pathogen. Medical students are frequently colonized by a variety of pathogens. Microbial interactions in the human nose can prevent or favor colonization by pathogens, and individuals colonized by pathogens have increased risk of infection and are the source of transmission to other community members or susceptible individuals. According to recent studies, the microbiome from several anatomic areas of healthy individuals varies across different ethnicities. Although previous studies analyzed the nasal microbiome in association with S. aureus carriage, those studies did not provide information regarding ethnicity of participants. Our aim was to assess S. aureus nasal carriage patterns and prevalence among medical students from Colombia, a country of Hispanic origin, and to investigate possible associations of colonization and nasal microbiome composition (bacterial and fungal) in a subgroup of students with known S. aureus carriage patterns.

Methods: Nasal swabs from second-year medical students were used to determine prevalence and patterns of S. aureus nasal carriage. Based on microbiological results, we assigned participants into one of three patterns of S. aureus colonization: persistent, intermittent, and non-carrier. Then, we evaluated the composition of nasal microbial communities (bacterial and fungal) in 5 individuals from each carriage category using 16S rRNA and Internal-Transcribed-Spacer sequencing.

Results: Prevalence of S. aureus nasal carriage among medical students was 28%. Carriage of methicillin-resistant strains was 8.4% and of methicillin-sensitive strains was 19.6%. We identified 19.6% persistent carriers, 17.5% intermittent carriers, and 62.9% non-carriers.

Conclusions: Analysis of nasal microbiome found that bacterial and fungal diversity was higher in individuals colonized by S. aureus than in non-carriers; however, the difference among the three groups was non-significant. We confirmed that fungi were present within the healthy anterior nares at substantial biomass and richness.
Silent myelin-weighted magnetic resonance imaging
Authors: Wood Tobias C. , Damestani Nikou L. , Lawrence Andrew J. , Ljungberg Emil , Barker Gareth J. , Solana Ana Beatriz , Wiesinger Florian , Williams Steven C.R.
Published: April 2020

Background: Inhomogeneous Magnetization Transfer (ihMT) is an emerging, uniquely myelin-specific magnetic resonance imaging (MRI) contrast. Current ihMT acquisitions utilise fast Gradient Echo sequences which are among the most acoustically noisy MRI sequences, reducing patient comfort during acquisition. We sought to address this by modifying a near silent MRI sequence to include ihMT contrast.

Methods: A Magnetization Transfer preparation module was incorporated into a radial Zero Echo-Time sequence. Repeatability of the ihMT ratio and inverse ihMT ratio were assessed in a cohort of healthy subjects. We also investigated how head orientation affects ihMT across subjects, as a previous study in a single subject suggests this as a potential confound.

Results: We demonstrated that ihMT ratios comparable to existing, acoustically loud, implementations could be obtained with the silent sequence. We observed that the ihMT ratio varied with the orientation of the head.

Conclusions: Silent ihMT imaging is a comparable alternative to conventional, noisy, alternatives. For all future ihMT studies we recommend careful attention should be paid to subject positioning within the scanner.
Evaluation of the professional teaching competence: chinese experience
Authors: Zhernovnykova Oksana , Kovalenko Oksana , Mkrtichian Oksana , Zelenska Liudmyla
Published: April 2020

The article describes the rules and procedures for hiring and evaluating the professional competence of teachers on the example ofChina, where there is a system for evaluating the professional competence of teachers.
The Development of backhand Drive Stroke Technique Training in Audiovisual Based for Beginner Badminton Athletes
Authors: Adiluhung Rezza , Kristiyanto Agus , Kunta Sapta
Published: April 2020

This research aimed to afford the backhand drive stroke technique training in audiovisual based for beginner category badminton athletes. This development research was referred to the development model that has been done by Borg & Gall and has been modified by Sugiyono into two steps, there were pre-development step and development step. The large scale testing was consisted of ten beginner category badminton athletes of PMS Surakarta. The effectiveness testing was done to 25 beginner category badminton athletes of PMS Surakarta by using pre-experiment Intact-Group Comparison, the groups were divided into two in order to make one group would be given a treatment, other group would be a control group. The result of the research showed that the group which was given backhand drive stroke technique training based on audiovisual treatment had higher scores than the control group.
Decremental Clustering for the Solution of p-Dispersion Problems to Proven Optimality
Authors: Contardo Claudio
Published: April 2020

Given n points, a symmetric dissimilarity matrix D of dimensions n × n, and an integer p ? 2, the p-dispersion problem (pDP) consists of selecting a subset of exactly p points in such a way that the minimum dissimilarity between any pair of selected points is maximum. The pDP is [Formula: see text] when p is an input of the problem. We propose a decremental clustering method to reduce the problem to the solution of a series of smaller pDPs until reaching proven optimality. A k-means algorithm is used to construct and refine the clusterings along the algorithm’s execution. The proposed method can handle problems orders of magnitude larger than the limits of the state-of-the-art solver for the pDP for small values of p.
Optimization of Regeneration Protocols of Chilies In Local Cultivars
Authors: Khan Mahnoor , Buneen Ummul , Naeem Sajid Syed , Nawaz Maliha , Harron Haseeb , hussain Imtiaz , Haseeb Abdul , Hassan Taj Muhammad , Nadeem Faisal , Kamran Rafique Muhammad , Akram Hamza
Published: April 2020

Retraction of " Optimization of Regeneration Protocols of Chilies in Local Cultivars" http://dx.doi.org/10.13005/bbra/2819 by as the author named himself as the corresponding author and published the article without the consent of his supervisor.
Improved model-based wavefront sensorless adaptive optics for extended objects using N + 2 images
Authors: Ren Hongxi , Dong Bing
Published: April 2020

The original model-based wavefront sensorless adaptive optics (WFSless AO) for extended objects uses the low spatial frequency content of images as the metric function and employs 2N + 1 images to correct N Lukosz aberration modes. We propose an improved method that uses the same metric but requires only N + 2 images to correct N aberration modes. The N + 2 method can achieve comparable corrective accuracy but requiring much smaller number of images compared with the 2N + 1 method. The N + 2 method is not only more efficient, but also provides the flexibility of choosing arbitrary basis modes by involving the non-orthogonality between modes in a linear least-squares optimization process. It is demonstrated that the deformable mirror’s influence functions modes (IFM), orthogonal mirror modes (OMM) and fitted Zernike modes (FZM) all can be used as modal basis for the N + 2 method to generate biased images. It is also proved that the N + 2 method is robust to image sampling rate and image noise, showing good prospects of applications in various imaging systems.
Enhancement of spectral response of Bragg gratings written in nanostructured and multi-stepped optical fibers with radially shaped GeO2 concentration
Authors: Osuch Tomasz , Anuszkiewicz Alicja , Zakrzewski Dawid , Filipkowski Adam , Olszewski Jacek , Mergo Paweł , Pysz Dariusz , Kasztelanic Rafał , Buczyński Ryszard
Published: April 2020

We present experimental results on fiber Bragg gratings inscription in nanostructured graded-index (nGRIN) and multi-step index (MSIN) optical fibers, both having non-uniform radial distribution of GeO2 dopant in the fiber cores. In particular, the positive role of radial shaping the GeO2 distribution in the fiber core on grating reflection efficiency is reported. We postulate that an appropriate spatial distribution of the germanium concentration that matches the fundamental mode profile improves grating spectral response due to more efficient grating-mode interaction, as compared with uniformly doped step-index optical fibers with the same overall doping level. Moreover, we show that radially shaped fibers exhibit moderately higher temperature responses than their step-index counterparts.
Electrochemically directed biofunctionalization of a lossy-mode resonance optical fiber sensor
Authors: Janik Monika , Niedziałkowski Paweł , Lechowicz Katarzyna , Koba Marcin , Sezemsky Petr , Stranak Vitezslav , Ossowski Tadeusz , Śmietana Mateusz
Published: April 2020

In this work, we present a direct electrochemical biofunctionalization of an indium-tin-oxide-coated lossy-mode resonance optical fiber sensor. The functionalization using a biotin derivative was performed by cyclic voltammetry in a 10 mM biotin hydrazide solution. All stages of the experiment were simultaneously verified with optical and electrochemical techniques. Performed measurements indicate the presence of a poly-biotin layer on the sensor’s surface. Furthermore, dual-domain detection of 0.01 and 0.1 mg/mL of avidin confirms the sensor’s viability for label-free detection.
Convolutional neural network-based signal demodulation method for NOMA-PON
Authors: Lin Bangjiang , Yang Hui , Wang Rui , Ghassemlooy Zabih , Tang Xuan
Published: April 2020

Non-orthogonal multiple access (NOMA) is a promising scheme for flexible passive optical networks (PONs), which provides high throughput and overall improved system performance. NOMA with the successive interference cancellation (SIC)-based receiver, which is used to detect the multiplexed signal in a sequential fashion, requires perfect channel state information and suffers from the error propagation problem. In this paper, we propose a convolutional neural network (CNN) based signal demodulation method for NOMA-PON, which performs channel estimation and signal detection in a joint manner. The CNN is first trained offline using the captured data for a given received optical power and then used to recover the data stream directly in the online mode. We show by experimental demonstration that, the proposed CNN-based receiver (Rx) outperforms the conventional SIC-based Rx and is more robust to the nonlinear distortion. We show that for the CNN-based system with 20 km optical fiber, the required received optical power levels at a bit error rate (BER) of 1×10−3 are lower by 4, 3 and 2.5 dB for power allocation ratios of 0.16, 0.25, 0.36, respectively compared with SIC-based system. In addition, the BER performance of CNN deteriorates considerably less with non-linear distortion compared with SIC.
Acceleration of autofocusing with improved edge extraction using structure tensor and Schatten norm
Authors: Ren Zhenbo , Lam Edmund Y. , Zhao Jianlin
Published: April 2020

Determining the optimal focal plane amongst a stack of blurred images in a short response time is a non-trivial task in optical imaging like microscopy and photography. An autofocusing algorithm, or in other words, a focus metric, is key to effectively dealing with such problem. In previous work, we proposed a structure tensor-based autofocusing algorithm for coherent imaging, i.e., digital holography. In this paper, we further extend the realm of this method in more imaging modalities. With an optimized computation scheme of structure tensor, a significant acceleration of about fivefold in computation speed without sacrificing the autofocusing accuracy is achieved by using the Schatten matrix norm instead of the vector norm. Besides, we also demonstrate its edge extraction capability by retrieving the intermediate tensor image. Synthesized and experimental data acquired in various imaging scenarios such as incoherent microscopy and photography are demonstrated to verify the efficacy of this method.
Nonlinear Fourier transform for characterization of the coherent structures in optical microresonators
Authors: Turitsyn Sergei K. , Chekhovskoy Igor S. , Fedoruk Mikhail P.
Published: April 2020

We propose and demonstrate, in the framework of the generic mean-field model, the application of the nonlinear Fourier transform (NFT) signal processing based on the Zakharov–Shabat spectral problem to the characterization of the round trip scale dynamics of radiation in optical fiber- and microresonators.
Isotropic three-dimensional imaging with lattice light-sheet difference microscopy
Authors: Zhang Chengfeng , Chen Yuchen , Liu Wenjie , Kuang Cuifang , Zhang Zhimin , Hao Xiang , Liu Xu
Published: April 2020

Through the interference of several beams with the same phase at the rear pupil, an optical lattice is generated and used as the excitation light field in lattice light-sheet microscopy (LLSM). Although, LLSM offers fast imaging ability through the dithered mode, it suffers from poor axial resolution. On the other hand, the structured illumination microscopy (SIM) mode in LLSM provides a high but anisotropic spatial resolution at the price of a lower imaging speed. In this Letter, we propose a new, to the best of our knowledge, type of optical lattice by defining the composed beam vectors with different phases. The lattice light-sheet difference microscopy (LLSDM) proposed in this work utilizes the new optical lattice along with the conventional one by simply changing the pattern loaded on the spatial light modulator. Through simulations with parameters obtained from the real acquisition procedures and the microscope properties, we examine the feasibility of LLSDM, and obtain nearly isotropic spatial resolution and great alleviation of the sidelobes. These characteristics enable LLSDM to broaden the accessible imaging content of light-sheet microscopes and further facilitate their applications in life sciences.
E-textiles: Power and resistance
Authors: Wilkins L. M.
Published: April 2020

On the precipice of space exploration, smart fabrics, biochips and exoskeletons, the materiality of our wearable and body-centric future is a critical and political issue. If we are to develop technologies to take us to new places, we should be able to imagine radically different futures. The materials, tools and supply chains available to us seed the future we can build and are fuel for the possibilities we can imagine. Textile-based Do It Yourself (DIY) electronics have been suggested in Maker technology circles as an alternative path to electronics to broaden the diversity of those imagining our future, but they are still heavily divided by lines of gender, and hindered by supply chain availability. There are many textile-based technologies that have unique technical qualities to offer, but their development is stifled by systemic issues. This article suggests that e-textile technologies are a result of an entrenched system of power and act as a control method over the vision of the future rather than the suggested notion that they are an avenue of exploration. Using Erbu Kurbak’s concept of Lost Futures, and Elizabeth Ryan’s interoperation of wearable technology as immaterial labour, I make the case for e-textile practice being a trap and never equal contributor to the technological discourse.
Morality by Design: Technology’s Challenge to Human Values, Wade Rowland (2019)
Authors: Heller Lynne
Published: April 2020

Review of: Morality by Design: Technology’s Challenge to Human Values, Wade Rowland (2019)

Bristol: Intellect, 120 pp.,

ISBN 978-1-78938-1-238, p/bk, $24
Асимптотические оценки разностей произведений функций Бесселя на интеграл от этих функций
Authors: Сабитов Камиль Басирович , Sabitov Kamil Basirovich
Published: April 2020

При исследовании прямых и обратных задач по отысканию правой части вырождающихся уравнений смешанного типа с различными граничными условиями возникает задача об установлении асимптотических оценок для разностей произведений цилиндрических функций на интеграл от этих функций. Предварительно на основании установленной новой формулы нахождения конечной биномиальной суммы вычислены разности произведений цилиндрических функций на определенный интеграл от этих функций через обобщенную гипергеометрическую функцию.
С использованием асимптотической формулы при больших значениях аргумента для обобщенной гипергеометрической функции установлены асимптотические оценки при больших значениях параметра для указанных разностей функций Бесселя первого и второго рода, а также для модифицированных функций Бесселя.
О расширении области для аналитического приближенного решения одного класса нелинейных дифференциальных уравнений второго порядка в комплексной области
Authors: Орлов Виктор Николаевич , Orlov Victor Nikolaevich , Леонтьева Татьяна Юрьевна , Leontieva Tatyana Yuryevna
Published: April 2020

Ранее авторами было проведено исследование одного класса нелинейных дифференциальных уравнений второго порядка в окрестности подвижной особой точки. Доказаны: существование подвижной особой точки, теорема существования и единственности решения в окрестности подвижной особой точки. Построено аналитическое приближенное решение в окрестности подвижной особой точки. Исследовано влияние возмущения подвижной особой точки на приближенное решение. Результаты, полученные для вещественной области, были обобщены на комплексную область $|z|<|\tilde z^*|\leqslant |z^*|$, где $z^*$ - точное значение подвижной особой точки, $\tilde z^*$ - приближенное значение подвижной особой точки. В данной работе проведено исследование аналитического приближенного решения от влияния возмущения подвижной особой точки в области $|z|> |\tilde z^*|\geqslant |z^*|$ с учетом изменения направления движения по лучу в направлении к началу координат комплексной плоскости. Эти исследования необходимы в силу характера подвижной особой точки (четная дробная степень критического полюса). Полученные результаты сопровождены численным экспериментом и завершают исследование аналитического приближенного решения рассматриваемого класса нелинейных дифференциальных уравнений в окрестности подвижной особой точки в зависимости от направления движения вдоль луча в комплексной области.
Интегро-дифференциальные уравнения второй краевой задачи линейной теории упругости.
Сообщение 2. Неоднородное анизотропное тело
Authors: Стружанов Валерий Владимирович , Struzhanov Valerii Vladimirovich
Published: April 2020

Ранее, в сообщении 1, были рассмотрены интегро-дифференциальные уравнения второй краевой задачи теории упругости для однородного изотропного тела. Полученные результаты распространены на краевые задачи для общего случая неоднородного анизотропного тела. Показано, что найденные интегро-дифференциальные уравнения также являются уравнениями фредгольмовского типа. Доказано существование и единственность их решения. Определены условия, при которых решение можно найти методом последовательных приближений. Приведен пример расчета остаточных напряжений в неоднородном закаленном цилиндре.
Упругопластический анализ вращающегося сплошного цилиндра при условии максимальных приведенных напряжений
Authors: Прокудин Александр Николаевич , Prokudin Aleksandr Nikolaevich
Published: April 2020

Рассматривается упругопластическое деформирование вращающегося сплошного цилиндра. Для постановки задачи используется теория малых деформаций и предположение о плоском деформированном состоянии в цилиндре. Пластические деформации определяются ассоциированным законом пластического течения и условием максимальных приведенных напряжений. Скорость вращения цилиндра монотонно возрастает от нуля до максимального значения, а затем монотонно убывает вплоть до полной остановки цилиндра. Предполагается, что скорость вращения медленно меняется со временем, поэтому угловым ускорением цилиндра можно пренебречь. При указанных предположениях в цилиндре остается одно нетривиальное уравнение равновесия.
Установлено, что в ходе нагрузки появляются четыре области пластического течения, которые соответствуют различным граням и ребрам поверхности текучести. При этом последняя из областей возникает уже после полного перехода цилиндра в состояние пластичности. Когда скорость вращения начинает уменьшаться, весь цилиндр вновь ведет себя, как упругое тело, а при определенной скорости в нем может начаться повторное (или вторичное) пластическое течение, характер которого зависит от максимальной скорости вращения. В общем случае появляются четыре вторичные пластические области. Напряженное состояние в первичных и вторичных пластических областях соответствует противоположным ребрам и граням поверхности текучести. В данной работе максимальная скорость вращения выбрана таким образом, чтобы в момент остановки весь цилиндр переходил в состояние повторного пластического течения. В этом случае возникают только две вторичные пластические области.
Найдены точные аналитические решения для всех стадий деформирования цилиндра. Сформулированы системы алгебраических уравнений для определения констант интегрирования и границ между областями. Полученные результаты проиллюстрированы графиками перемещений, напряжений и пластических деформаций. Произведено сравнение с известными решениями, найденными с использованием условия Треска.
Численное моделирование несоосных цилиндрических оболочек,
частично заполненных жидкостью
Authors: Бочкарев Сергей Аркадьевич , Bochkarev Sergey Arkadievich , Лекомцев Сергей Владимирович , Lekomtsev Sergey Vladimirovich , Сенин Александр Николаевич , Senin Aleksandr N.
Published: April 2020

Работа посвящена численному анализу динамического поведения горизонтально ориентированных несоосных оболочек, кольцевой зазор между которыми полностью или частично заполнен текущей жидкостью. Решение задачи осуществляется в трeхмерной постановке с использованием метода конечных элементов. При моделировании упругих тел предполагается, что их криволинейная поверхность достаточно точно аппроксимируется совокупностью плоских сегментов, деформации в которых определяются с помощью соотношений классической теории пластин. Движение идеальной сжимаемой жидкости описывается волновым уравнением, которое совместно с условием непроницаемости и соответствующими граничными условиями преобразуется с помощью метода Бубнова-Галeркина. Математическая постановка задачи динамики тонкостенных конструкций основана на вариационном принципе возможных перемещений. Оценка устойчивости базируется на вычислении и анализе комплексных собственных значений связанной системы уравнений. Верификация модели произведена для случая неподвижной жидкости путeм сопоставления результатов с известными решениями. Представлен анализ влияния величины кольцевого зазора и уровня его заполнения жидкостью при различном значении эксцентриситета между осями вращения жeстко закреплeнных с обоих краeв оболочек на границы гидроупругой устойчивости. Показано, что для несоосных оболочек уменьшение уровня заполнения приводит к повышению границ устойчивости. Продемонстрирована зависимость критической скорости течения жидкости от отклонения внутренней оболочки от соосного положения.