bluuebunny/crossref_metadata_2025 huggingface dataset:
Extraordinary sensitivity enhancement of Ag-Au alloy nanohole arrays for label-free detection of Escherichia Coli
Authors: Hwang Charles Soon Hong , Ahn Myeong-su , Jeong Ki-Hun
Published: April 2021

Alloy nanostructures unveil extraordinary plasmonic phenomena that supersede the mono-metallic counterparts. Here we report silver-gold (Ag-Au) alloy nanohole arrays (α-NHA) for ultra-sensitive plasmonic label-free detection of Escherichia Coli (E. coli). Large-area α-NHA were fabricated by using nanoimprint lithography and concurrent thermal evaporation of Ag and Au. The completely miscible Ag-Au alloy exhibits an entirely different dielectric function in the near infra-red wavelength range compared to mono-metallic Ag or Au. The α-NHA demonstrate substantially enhanced refractive index sensitivity of 387 nm/RIU, surpassing those of Ag or Au mono-metallic nanohole arrays by approximately 40%. Moreover, the α-NHA provide highly durable material stability to corrosion and oxidation during over one-month observation. The ultra-sensitive α-NHA allow the label-free detection of E. coli in various concentration levels ranging from 103 to 108 cfu/ml with a calculated limit of detection of 59 cfu/ml. This novel alloy plasmonic material provides a new outlook for widely applicable biosensing and bio-medical applications.
Converting an array of edge dislocations into a multi-vortex beam
Authors: Kotlyar Victor V. , Kovalev Alexey A.
Published: April 2021

We theoretically show how, using a cylindrical lens, a Gaussian beam with a finite number of parallel zero-intensity lines (edge dislocations) is transformed into a vortex beam that carries orbital angular momentum (OAM) and topological charge (TC). Remarkably, while the original beam is assumed to carry a non-zero OAM and have no TC, the latter is shown to appear during free-space propagation. Considering two parallel center-symmetric zero-intensity lines located as an example, we look into the dynamics of generating two intensity nulls at the double focal length: with increasing distance between the vertical zero-intensity lines, two optical vortices are first generated on the horizontal axis before converging at the origin and then diverging along the vertical axis. Irrespective of the between-line distance, such an optical vortex has

T
C

=
−

2

at any distance from the optical axis, except for the original plane. With changing distance between the zero-intensity lines, the OAM that the beam carries is changing, taking positive and negative values, or a zero value at a certain between-line distance. We also show that if the number of zero-intensity lines is infinite, a vortex beam with finite OAM and infinite TC is generated.
Semi-analytical approach for refractive index sensors based on reflective metasurfaces
Authors: Vasić Borislav
Published: April 2021

We present a semi-analytical approach for the analysis and design of refractive index sensors based on metal–insulator–metal (MIM) metasurfaces. While numerical methods require extensive calculations for all values of geometrical parameters, the semi-analytical approach provides straightforward guidelines for a design of optimal metasurfaces with maximized sensitivity. Semi-analytical formulas for refractive index sensitivities are derived from equations of the temporal coupled mode theory and standing-wave resonance model. They require three numerically calculated parameters (resonant frequency and radiative and non-radiative decay rates of the resonant mode), obtained by the fitting of reflectance spectra. Generality of the presented approach allows us to consider the operation of metasurface sensors in three different interrogation methods: spectral (frequency), intensity (reflectance), and phase. Validity of the proposed approach is confirmed by a good agreement with numerical results. Starting from semi-analytical formulas, we derive working frequencies of metasurface based sensors, prove that the critical coupling with equal decay rates of the resonant mode is the optimal working regime, and demonstrate that optimal MIM metasurfaces should have periods as large as possible with the thickness of MIM cavities determined by the critical coupling condition.
Laser back-writing of steel for fabrication of micro-channels on a quartz substrate
Authors: Abbasi Shabnam , Jafarfard Mohammad Reza , Razaghi Davood , Montazerolghaem Mohsen , Pazokian Hedieh
Published: April 2021

The present study aimed to apply laser back-writing for fabricating micro-channels. First, a

Q

-switched Nd:YAG laser with fundamental wavelength was used, and a steel target was ablated and evaporated onto a quartz substrate by focusing the laser pulses on the target through the quartz substrate. Then, micro-channels on the quartz were machined with laser-ablated plasma interaction with the substrate. In addition, the surface plasma ablated region was characterized by scanning electron microscopy, a surface profilometer, and energy dispersive x-ray spectrometry. Finally, UV-Vis spectroscopy was used to measure the presence of metal nanoparticles with their typical surface plasmon resonance bands on the interaction area.
Temperature self-calibrated pH sensor based on GO/PVA-coated MZI cascading FBG
Authors: Yan Ran , Sang Guofeng , Yin Bin , Wu Songhua , Wang Muguang , Hou Benran , Gao Mingquan , Chen Rong , Yu Han
Published: April 2021

A temperature self-calibrated potential of hydrogen (pH) sensor based on the single mode fiber-tapered dual core photonic crystal fiber-single mode fiber (SMF-TDCPCF-SMF) structure cascaded with a fiber Bragg grating (FBG) is proposed and demonstrated. The TDCPCF structure formed Mach-Zehnder interferometer (MZI) is modified with a coating of graphene oxide/polyvinyl alcohol (GO/PVA) hybrid hydrogel to realize the measurement of pH, and the uncoated FBG is used to calibrate temperature. In our experiment, the sensitivity coefficient of 0.69 nm/pH with R2=0.99 and the hysteresis loss of less than 0.007 are achieved within the pH range from pH 4.00 to pH 9.85. The measured response time from pH 7.00 to pH 4.00, 6.00 and 9.85 are no higher than 10s. Moreover, the resonant wavelengths of MZI and FBG also exhibit good linear relationship with the temperature sensitivity coefficient of 0.15 nm/°C (R2=0.99) and 0.09 nm/°C (R2=0.97) respectively. It is demonstrated successfully that the proposed sensor has broad application prospects in the field of environmental monitoring, biological sensing and chemical analysis, due to the good performance of the temperature self-calibrated pH monitoring, repeatability, linearity, response time and reversibility.
Switching the orbital angular momentum state of light with mode sorting assisted coherent laser array system
Authors: Hou Tianyue , Chang Qi , Yu Tao , Long Jinhu , Chang Hongxiang , Ma Pengfei , Su Rongtao , Ma Yanxing , Zhou Pu
Published: April 2021

Light beams carrying orbital angular momentum (OAM) have important implications for future classical and quantum systems. In many applications, controlled switching of the OAM state at high speed is crucial, while accelerating the switching rate presents a long-standing challenge. Here we present a method for flexibly switching the OAM state of light based on a coherent laser array system. In the system, the output structured light beam is tailored by the coherent combination of array elements. By employing an OAM mode sorting assisted phase control subsystem, which continuously performs the optimization algorithm, the dynamic wavefront distortion of the combined OAM beam could be compensated. Meanwhile, our approach allows one to achieve fast states switching of the combined OAM beam via programming the cost function of the algorithm. The results of Monte-Carlo simulations demonstrate the feasibility of the proposed method, and the mode purity and power scaling potential of the controllably generated OAM beam are discussed. This theoretical work could be beneficial to the future implementation of rapidly switchable OAM beams at practical output power.
Brillouin optical correlation-domain reflectometry based on arbitrary waveform modulation: a theoretical study
Authors: Noda Kohei , Lee Heeyoung , Nakamura Kentaro , Mizuno Yosuke
Published: April 2021

We put forward a new theory on Brillouin optical correlation-domain reflectometry (BOCDR) based on arbitrary waveform modulation. We derive a universal representation for the spatial resolution using the foot convexity of the beat spectrum. This result well explains the previous results based on sinusoidal modulation, and thus our theory is the consistent extension of the conventional theory on BOCDR. This representation is also applicable to the spatial resolution evaluation of more complicated modulation schemes, such as the combined use of intensity and frequency modulations even with some phase delay. We also discuss what kinds of modulation waveforms should not be employed for distributed measurement to ensure high spatial resolution.
Designing double freeform surfaces for large ray bending irradiance tailoring of extended LED sources
Authors: Li Yuyin , Feng Zexin , Cheng Dewen , Wang Yongtian
Published: April 2021

Many illumination applications require redistributing the irradiance distributions of LED sources with large ray bending. The problem becomes even more challenging for a compact design where the LED size is no longer ignorable. We tackle this problem by simultaneously designing two freeform optical surfaces. An iterative wavefront tailoring (IWT) method is adapted for obtaining the entrance and exit base freeform surfaces with a predefined ray bending regulation under stereographic coordinates (u, v). The simulated annealing (SA) algorithm is employed for deforming the two base freeform surfaces using the 'uv' polynomials with the purpose of minimizing the relative root-mean-square deviation (RRMSD) between the simulated irradiance distribution and the prescribed one. The optimizations are implemented in an automated workflow which links the optimization engine, 3D modeling software and ray tracing software. The effectiveness of the proposed method is illustrated by designing several double-freeform-surface lenses (central heights: 10 mm) with different ray bending regulated base surfaces and 10-th order uv polynomial departures for generating 500 × 200 mm2 uniform irradiance distributions at a distance of 100 mm from 2 × 2 mm2 and 3 × 3 mm2 sources, respectively.
Spherical concave micro-mirror fabricated using gray-tone optical lithography for vertical coupling
Authors: Wang Xueting , Deng Chuanlu , Huang Yi , Zhang Fang , Zhang Ruhuan , Zhang Xiaobei , Wang Tingyun
Published: April 2021

Based on gray-tone optical lithography technology combined with the overlay alignment method, a spherical concave micro-mirror is fabricated at the end of a rectangular optical waveguide (ROW) for low vertical coupling loss. The optimal structures of the spherical concave micro-mirrors were designed through ray-tracing simulation. The results indicate that the minimal vertical coupling loss is only 1.02 dB for the ROW core size of 20 μm × 20 μm. The surface roughness of the micro-mirror is considered, and it should be less than 106 nm to ensure that the vertical coupling loss is less than 1.5 dB. The radius of the fabricated spherical concave micro-mirror was measured as 263.3 μm and the surface roughness of the micro-mirror is 29.19 nm. The vertical coupling loss induced by the micro-mirror was measured as 1.39 dB. 1-dB tolerances in the direction of x-, y-, and z-axes are calculated to be ± 6.9 μm, ± 6.3 μm, and 46.2 μm, respectively.
Microwave pulse generation via employing an electric signal modulator to achieve time-domain mode locking in an optoelectronic oscillator
Authors: Zeng Zhen , Zhang Lingjie , Zhang Yaowen , Tian Huan , Zhang Zhiyao , Zhang Shangjian , Li Heping , Liu Yong
Published: April 2021

An actively mode-locked optoelectronic oscillator (OEO) is proposed and
demonstrated to generate chirp-free microwave pulse trains with
variable repetition rates. Time-domain mode locking is realized by
using an electric signal modulator to achieve amplitude modulation of
the generated microwave signal in the OEO cavity. Through setting the
externally applied electric signal frequency to be equal to the
integral multiple of the free spectral range, a microwave pulse train
with a low close-to-carrier phase noise is generated. In the
experiment, microwave pulse trains with repetition rates of 179.94 and
360.00 kHz are generated through fundamental mode locking and
2nd-order harmonic mode locking, respectively. Under fundamental mode
locking, the phase noise of the actively mode-locked OEO at 100 Hz
frequency offset is measured to be 30 dB lower than that in a
free-running OEO.
Revisiting spontaneous Raman scattering for direct oxygen atom quantification
Authors: van de Steeg A. W. , Vialetto L. , Silva A. F. , Peeters F. J. J. , van den Bekerom D. C. M. , Gatti N. , Diomede P. , van de Sanden M. C. M. , van Rooij G. J.
Published: April 2021

In this Letter, the counterintuitive and largely unknown Raman activity of oxygen atoms is evaluated for its capacity to determine absolute densities in gases with significant O-density. The study involves

C
O

2

microwave plasma to generate a self-calibrating mixture and establish accurate cross sections for the

3

P
2

↔
3

P
1

and

3

P
2

↔
3

P
0

transitions. The approach requires conservation of stoichiometry, confirmed within experimental uncertainty by a 1D fluid model. The measurements yield

σ

J
=
2
→
1

=
5.27

±

s
y
s

:
0.53

r
a
n
d

:
0.17

×

10

−
31

c
m

2

/

s
r

and

σ

J
=
2
→
0

=
2.11

±

s
y
s

:
0.21

r
a
n
d

:
0.06

×

10

−
31

c
m

2

/

s
r

, and the detection limit is estimated to be

1
×

10

15

c
m

−
3

for systems without other scattering species.
219.6  W large-mode-area Er:Yb codoped fiber amplifier operating at 1600  nm pumped by 1018  nm fiber lasers
Authors: Yu Weilong , Xiao Qirong , Wang Lele , Zhao Ying , Qi Tiancheng , Yan Ping , Gong Mali
Published: April 2021

We demonstrate, to the best of our knowledge, the first high-power large-mode-area Er:Yb codoped fiber amplifier pumped by 1018 nm fiber lasers. The output power reaches 219.6 W, which is the highest power operating at 1600 nm with near-diffraction-limitation beam quality. The 1018 nm pumping scheme contributes to the mitigation of Er,Yb fiber bottlenecking, improvement in signal gain, and reduction of heat generation. Also, we inject co-propagating C-band amplified spontaneous emission (ASE) into the master amplifier to avoid unwanted backward-propagating ASE.
The effect of Moringa oleifera capsule in increasing breastmilk volume in early postpartum patients: A double-blind, randomized controlled trial
Authors: Fungtammasan Siraphat , Phupong Vorapong
Published: April 2021

Moringa oleifera is an herbal galactagogue that has been used to increase the volume of breastmilk. Few studies have evaluated the effect of Moringa oleifera in breastfeeding. There are conflicting data whether it can increase the volume of breastmilk or not. Thus, the objective of this study is to evaluate the efficacy of Moringa oleifera leaves in increasing the volume of breastmilk in early postpartum mothers. A randomized, double-blind, placebo-controlled trial will be conducted. The outcomes of this study will provide the data of Moringa oleifera as an herbal medication to increase the volume of breastmilk. This information will be used to increase the rate of exclusive breastfeeding for the first 6 months as recommended by the World Health Organization.

Clinical trial registration

This clinical trial was registered at ClinicalTrials.gov (Clinical trials registration: NCT04487613).
Analysis of English free association network reveals mechanisms of efficient solution of Remote Association Tests
Authors: Valba Olga , Gorsky Alexander , Nechaev Sergei , Tamm Mikhail
Published: April 2021

We study correlations between the structure and properties of a free association network of the English language, and solutions of psycholinguistic Remote Association Tests (RATs). We show that average hardness of individual RATs is largely determined by relative positions of test words (stimuli and response) on the free association network. We argue that the solution of RATs can be interpreted as a first passage search problem on a network whose vertices are words and links are associations between words. We propose different heuristic search algorithms and demonstrate that in “easily-solving” RATs (those that are solved in 15 seconds by more than 64% subjects) the solution is governed by “strong” network links (i.e. strong associations) directly connecting stimuli and response, and thus the efficient strategy consist in activating such strong links. In turn, the most efficient mechanism of solving medium and hard RATs consists of preferentially following sequence of “moderately weak” associations.
Population structure, case clusters, and genetic lesions associated with Canadian Salmonella 4,[5],12:i:- isolates
Authors: Clark Clifford G. , Kearney Ashley K. , Tschetter Lorelee , Robertson James , Pollari Frank , Parker Stephen , Arya Gitanjali , Ziebell Kim , Johnson Roger , Nash John , Nadon Celine
Published: April 2021

MonophasicSalmonella4,[5]:12:i:- are a major public health problem because they are one of the top fiveSalmonellaserotypes isolated from clinical cases globally and because they can carry resistance to multiple antibiotics. A total of 811Salmonella4,[5]:12:i:- andS. Typhimurium whole genome sequences (WGS) were generated. The various genetic lesions causing theSalmonella4,[5]:12:i:- genotype were identified and assessed with regards to their distribution in the population of 811Salmonella4,[5]:12:i:- andS. Typhimurium isolates, their geographical and temporal distribution, and their association with non-human sources. Several clades were identified in the population structure, and the largest two were associated almost exclusively with a short prophage insertion and insertion of a mobile element carrying loci encoding antibiotic and mercury resistance.IS26-mediated deletions andfljBpoint mutants appeared to spread clonally. ‘Inconsistent’Salmonella4,[5]:12:i:- isolates associated with specific, single amino acid changes infljAandhinwere found in a single clade composed of water, shellfish, and avian isolates. Inclusion of isolates from different case clusters identified previously by PFGE validated some of the clusters and invalidated others. Some wgMLST clusters of clinical isolates composed of very closely related isolates contained an isolate(s) with a different genetic lesion, suggesting continuing mobility of the implicated element responsible. Such cases may need to be left out of epidemiological investigations until sufficient numbers of isolates are included that statistical significance of association with sources is not impaired. Non-human sources were frequently found in or near clinical case clusters. Prospective surveillance and WGS of non-human sources and retrospective analysis by WGS of isolates from existing culture collections provides data critical for epidemiological investigations of food- and waterborne outbreaks.
Seroprevalence of anti-SARS-CoV-2 antibodies in Japanese COVID-19 patients
Authors: Hiki Makoto , Tabe Yoko , Ai Tomohiko , Matsue Yuya , Harada Norihiro , Sugimoto Kiichi , Matsushita Yasushi , Matsushita Masakazu , Wakita Mitsuru , Misawa Shigeki , Idei Mayumi , Miida Takashi , Tamura Naoto , Takahashi Kazuhisa , Naito Toshio
Published: April 2021

Objectives

To determine the seroprevalence of anti-SARS-CoV-2 IgG and IgM antibodies in symptomatic Japanese COVID-19 patients.

Methods

Serum samples (n = 114) from 34 COVID-19 patients with mild to critical clinical manifestations were examined. The presence and titers of IgG antibody for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were determined by a chemiluminescent microparticle immunoassay (CMIA) using Alinity i SARS-CoV-2 IgG and by an immunochromatographic (IC) IgM/IgG antibody assay using the Anti-SARS-CoV-2 Rapid Test.

Results

IgG was detected by the CMIA in 40%, 88%, and 100% of samples collected within 1 week, 1–2 weeks, and 2 weeks after symptom onset in severe and critical cases, and 0%, 38%, and 100% in mild/moderate cases, respectively. In severe and critical cases, the positive IgG detection rate with the IC assay was 60% within one week and 63% between one and two weeks. In mild/moderate cases, the positive IgG rate was 17% within one week and 63% between one and two weeks; IgM was positive in 80% and 75% of severe and critical cases, and 42% and 88% of mild/moderate cases, respectively. On the CMIA, no anti-SARS-CoV-2 IgG antibodies were detected in COVID-19 outpatients with mild symptoms within 10 days from onset, whereas 50% of samples from severe inpatients were IgG-positive in the same period. The IC assay detected higher IgM positivity earlier from symptom onset in severe and critical cases than in mild/moderate cases.

Conclusions

A serologic anti-SARS-CoV-2 antibody analysis can complement PCR for diagnosing COVID-19 14 days after symptom onset.
Assessing required SARS-CoV-2 blanket testing rates for possible control of the outbreak in the epicentre Lusaka province of Zambia with consideration for asymptomatic individuals: A simple mathematical modelling study
Authors: Sichone Joseph , Sinkala Musalula , Munsaka Sody , Kikonko Mervis , Simuunza Martin
Published: April 2021

Introduction

The novel Coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus—2 (SARS-CoV-2), in Africa is characterised by a more substantial proportion of asymptomatic (or mildly symptomatic) individuals thought to be playing a role in the spread of the infection. The exact proportion and degree of infectiousness of asymptomatic individuals remains unclear. Studies however indicate that their management is crucial for control of SARS-CoV-2 transmission.

Methodology

We developed a simplified deterministic susceptible-exposed-infectious-removed (SEIR) mathematical model to assess the effect of active isolation of SARS-CoV-2 infected but asymptomatic individuals through blanket testing for control of the outbreak in Lusaka Province of Zambia. Here we modelled two scenarios; (1) assuming asymptomatic individuals comprised 70% of all COVID-19 cases and (2) asymptomatic individuals comprised only 50% of the cases. For contrast, the model was assessed first under the assumption that asymptomatic individuals are equally as infectious as symptomatic individuals and then secondly, and more likely, assuming asymptomatic individuals are only half as infectious as symptomatic individuals.

Results

For the model assuming 70% asymptomatic cases, a minimum sustained daily blanket testing rate of ≥ 7911 tests/100000 population was sufficient to control the outbreak if asymptomatic individuals are only half as infectious while if equal infectiousness was assumed then a testing rate of ≥ 10028 tests/ 100000 population would be required. For 50% asymptomatic, minimum blanket testing rates of ≥ 4540 tests/ 100000 population was sufficient to control the outbreak at both assumed levels of infectiousness for asymptomatic individuals relative to symptomatic individuals.

Discussion and conclusion

Our model predicts that active isolation of COVID-19 cases, including asymptomatic individuals, through blanket testing can be used as a possible measure for the control of the SARS-Cov-2 transmission in Lusaka, Zambia, but it would come at a high cost.
Challenges during the execution, results, and monitoring phases of ecological restoration: Learning from a country-wide assessment
Authors: Méndez-Toribio Moisés , Martínez-Garza Cristina , Ceccon Eliane
Published: April 2021

Outcomes from restoration projects are often difficult for policymakers and stakeholders to assess, but this information is fundamental for scaling up ecological restoration actions. We evaluated technical aspects of the interventions, results (ecological and socio-economic) and monitoring practices in 75 restoration projects in Mexico using a digital survey composed of 137 questions. We found that restoration projects in terrestrial ecosystems generally relied on actions included in minimal (97%) and maximal (86%) intervention, while in wetlands, the preferred restoration strategies were intermediate (75%) and minimal intervention (63%). Only a third of the projects (38%) relied on collective learning as a source of knowledge to generate techniques (traditional management). In most of the projects (73%), multiple criteria (>2) were considered when selecting plant species for plantings; the most frequently used criterion was that plant species were found within the restoration area, native or naturalized (i.e., a circa situm criterion; 88%). In 48% of the projects, the biological material required for restoration (e.g., seeds and seedlings) were gathered or propagated by project implementers rather than purchased commercially. Only a few projects (between 33 and 34%) reached a high level of biodiversity recovery (>75%). Most of the projects (between 69 to71%) recovered less than 50% of the ecological services. Most of the projects (82%) led to improved individual relationships. The analysis revealed a need to implement strategies that are cost-effective, the application of traditional ecological knowledge and the inclusion of indigenous people and local communities in restoration programs at all stages—from planning to implementation, through monitoring. We also identified the need to expand research to develop effective tools to assess ecosystems’ regeneration potential and develop theoretical frameworks to move beyond short-term markers to set and achieve medium- and long-term goals. Cautious and comprehensive planning of national strategies must consider the abovementioned identified gaps.
Tim-3 is dispensable for allergic inflammation and respiratory tolerance in experimental asthma
Authors: Boehne Carolin , Behrendt Ann-Kathrin , Meyer-Bahlburg Almut , Boettcher Martin , Drube Sebastian , Kamradt Thomas , Hansen Gesine
Published: April 2021

T cell immunoglobulin and mucin domain-containing molecule-3 (Tim-3) has been described as a transmembrane protein, expressed on the surface of various T cells as well as different cells of innate immunity. It has since been associated with Th1 mediated autoimmune diseases and transplantation tolerance studies, thereby indicating a possible role of this receptor in counter-regulation of Th2 immune responses. In the present study we therefore directly examined the role of Tim-3 in allergic inflammation and respiratory tolerance. First, Tim-3-/- mice and wild type controls were immunized and challenged with the model allergen ovalbumin (OVA) to induce an asthma-like phenotype. Analysis of cell numbers and distribution in the bronchoalveolar lavage (BAL) fluid as well as lung histology in H&E stained lung sections demonstrated a comparable degree of eosinophilic inflammation in both mouse strains. Th2 cytokine production in restimulated cell culture supernatants and serum IgE and IgG levels were equally increased in both genotypes. In addition, cell proliferation and the distribution of different T cell subsets were comparable. Moreover, analysis of both mouse strains in our respiratory tolerance model, where mucosal application of the model allergen before immunization, prevents the development of an asthma-like phenotype, revealed no differences in any of the parameters mentioned above. The current study demonstrates that Tim-3 is dispensable not only for the development of allergic inflammation but also for induction of respiratory tolerance in mice in an OVA-based model.
Allometric association between physical fitness test results, body size/shape, biological maturity, and time spent playing sports in adolescents
Authors: Giuriato Matteo , Kawczynski Adam , Mroczek Dariusz , Lovecchio Nicola , Nevill Alan
Published: April 2021

Regular participation in strength and conditioning activities positively correlates with health-related benefits in sports (team and individual). Maturity offset (MO) is a recognized parameter in fitness outcome assessment. The aims of the present study are to analyze cross-sectional allometric development of motor performances in a sample of adolescents and relate scaled motor performance to the estimated amount and type of physical activity and biological maturity status in 771 subjects aged 14–19 years. Three physical fitness components were evaluated using field tests (standing broad jump, sit-ups, shuttle run). Extra hours of sport after school (EHS) and MO were the covariates. The model to predict the physical performance variables was: Y = a · Mk1· Hk2· WCk3· exp(b · EHS + c · MO) · ε. Results suggest that having controlled for body size and body shape, performing EHS and being an early developer (identified by a positive MO slope parameter) benefits children in physical fitness and motor performance tasks.
Analysis in silico of the single nucleotide polymorphism G–152A in the promoter of the angiotensinogen gene of Indonesian patients with essential hypertension
Authors: Susanto Akhiyan Hadi , Widodo  , Rohman Mohammad Saifur , Utomo Didik Huswo , Lukitasari Mifetika
Published: April 2021

Background

Single nucleotide polymorphism (SNP) G–152A (rs11568020) in the promoter of the angiotensinogen gene (AGT) may modulate its transcription. Translation of mRNA to angiotensinogen induces hypertension during hypoxia. The G allele at position –152 is located within the hypoxia-response element (HRE) transcription factor-binding site for the hypoxia-inducible factor 1 (HIF-1) heterodimer. However, the function of the –152 site in HIF-1 binding is not fully elucidated.

Objectives

To determine the frequency of SNP G–152A in Indonesian patients with hypertension and the function of this SNP.

Methods

We determined the frequency of the SNP in 100 patients by direct sequencing, and the influence of SNP G–152A on predicted binding of HIF-1 to the HRE using a docking approach in silico.

Results

The AGT promoter in our patients had genetic variants –152G and –152A (19:1). Predicted binding indicated that HIF-1 directly contacts the major groove of the G allele, but not the A allele. Scoring according to weighted sum High Ambiguity Driven biomolecular DOCKing showed that the score for the A allele–HIF-1 complex (–47.1 ± 6.9 kcal/mol) was higher than that for the G allele–HIF-1 complex (–94.6 ± 14.1 kcal/mol), indicating more favorable binding of HIF-1 to the G allele.

Conclusions

SNP G–152A reduces the favorability of binding of HIF-1 to the HRE. The occurrence of this SNP in the AGT promoter of Indonesian patients with essential hypertension suggests that the G allele is a genetic susceptibility factor in hypertension regulated by HIF-1.
Methods of Test for Concrete Permeability: A Critical Review
Authors: Milla Jose , Cavalline Tara L. , Rupnow Tyson D. , Melugiri-Shankaramurthy Bharath , Lomboy Gilson , Wang Kejin
Published: April 2021

The transport of liquids, gasses, and aggressive agents into concrete is responsible for a variety of durability issues. To obtain the low-permeability concrete required for long-lasting, sustainable infrastructure, stakeholders desire the ability to specify concrete based upon the permeability rating for specific uses. The mechanisms of moisture ingress into concrete are complex phenomena, and they are highly dependent on materials, mixture characteristics, curing conditions, and other factors. This review article provides an overview of the available permeability test methods and identifies existing gaps in the current field and knowledge. It discusses the mechanisms and key factors influencing moisture movement within concrete (capillary suction, absorption, water, and gas permeability) and outlines the procedures, advantages, and limitations of available permeability test methods. Despite a variety of tests available for water permeability, widespread acceptance for use of a single (or even a few) tests has not been achieved. No clear link exists between these tests and acceptable field performance. Additionally, several tests are viewed as problematic from a time, cost, or variability standpoint. Therefore, improved rapid permeability tests are needed to provide a pathway for agencies to move toward performance specifications with confidence. Recommendations regarding future work to support the development of improved test methods and, potentially, a model that would predict moisture ingress based on electrical resistivity, are also presented.
A Nondestructive Longitudinal Laboratory Test Method for Detection of Incipient Ultrastructural Changes in Wood
Authors: Lepage Robert , Glass Samuel V. , de la Bastide Paul Y. , Mukhopadhyaya Phalguni
Published: April 2021

The established methods for determining the effects of ultrastructural changes in structural wood members rely upon traditional, possibly outmoded, testing paradigms. These methods usually involve destructive testing of wood specimens that are exposed to environmental conditions infrequently experienced in buildings. Understanding how the ultrastructure changes with time within the same specimen is crucial for building practitioners in assessing risks to life-safety, assessing remaining service life of structural components, and aiding in the identification of mitigation or remediation measures. The primary agents causing ultrastructural modifications to wood are wood rotting basidiomycetes but may also include other biotic and abiotic agents; the methods contained herein should be applicable to all such longitudinal experiments. This article reviews existing literature on decay testing and validates a new method to assess longitudinal changes in mechanical properties with time using nondestructive test measures at relevant moisture contents. The validation testing shows this method has a good degree of repeatability and should permit the initial detection and monitoring of ultrastructure changes (e.g., decay). The method uses a repeatable, nondestructive four-point testing procedure for specimens controlled to specific moisture contents using energy dissipation as the salient performance metric. Recommendations are provided to refine this novel test method.
Umverteilung von Arbeit(-szeit): Eine (Netto)Kostenschätzung für ein staatlich gefördertes Arbeitszeitverkürzungsmodell
Authors: Figerl Jürgen , Tamesberger Dennis , Theurl Simon
Published: April 2021

Dieser Beitrag skizziert ein konkretes staatlich gefördertes Arbeitszeitverkürzungs-Modell, das in der Lage ist Arbeitslosigkeit zu senken. Die Vollarbeitszeit kann hier um bis zu 20 Prozent reduziert werden. Wenn vier Beschäftigte im Betrieb reduzieren, muss eine zuvor arbeitslose Person eingestellt werden. Das Unternehmen zahlt die gesamten Lohnkosten für die geleistete Arbeitszeit. Im Gegensatz zum Solidaritätsprämienmodell ist bei diesem Vorschlag die Arbeitszeitverkürzungsbeihilfe (Bruttoersatzraten von 100/95/90 Prozent) wesentlich höher, was wichtig ist, damit sich die Arbeitnehmer*innen mit geringem Einkommen eine Arbeitszeitverkürzung leisten können. Die Nettokosten für die Arbeitszeitverkürzungs-Förderung für 200.000 Beschäftigte und für die Integration von 50.000 Arbeitslosen würden je nach Höhe der Einkommen der geförderten Beschäftigten zwischen Nettomehreinnahmen von 151 Mio. Euro bis zu Nettomehrausgaben für den Staat von rund 1 Mrd. Euro liegen. Dieses Modell kann ein Teil eines vollbeschäftigungsorientierten Policy-Mix sein, der die betriebliche Experimentierfreudigkeit fördert und Wirkungen entfaltet, die gesamtgesellschaftlich bedeutend sind.
Impact of large human constructions on a karst river hydrology: Case of the Cetina river (Dinaric karst)
Authors: Bonacci Ognjen , Andrić Ivo , Roje-Bonacci Tanja , Oskoruš Dijana , Vrsalović Adrijana
Published: April 2021

The paper studies drastic hydrological changes caused by construction of five reservoirs and six hydro-electric power plants (HEPP), built mostly in the 1960s, along the watercourse of the karst river Cetina, located in deep and well-developed Dinaric karst. The total river length from its spring to mouth in the Adriatic Sea is about 105 km. Discharges are monitored at nine gauging stations and then compared using statistical methods. Discharges measured before construction of hydraulic structures were compared with discharges measured afterwards. Analysis of the results determined that the complex natural hydrologic regime has been completely destroyed. The hydrology of the upper river, from the spring to the Prančevići Dam (length of about 65 km), is changed by the development and operation of the Peruča Reservoir and the Peruča HEPP, as well as the Lipa and the Buško Blato Reservoirs and Buško Blato and Orlovac HEPPs. Water diversion from the Prančevići Reservoir through two tunnels and pipelines to power the Zakučac HEPP has dangerously altered hydrological regime of the Cetina River’s 40 km-long downstream section. In the 65 km-long upstream section, instantaneously after the Peruča Reservoir putting in operation. In the downstream section the majority of natural flow is lost. The mean annual discharges dropped from more than 100 m3 s-1 to less than 10 m3 s-1. Due to HEPPs operation, minimum annual discharges have drastically and dangerously decreased.
Challenges of private provision of potable water in Obio/Akpor Local Government Area and its Socio-economic implications
Authors: Brown Ibama , Chikagbum Wocha , I Weje Innocent
Published: April 2021

Water is a basic and necessary requirement for the existence of animals and plants, yet it is limited in supply in several parts of the world. Surges in human population and demand for water for different purposes such as agricultural, domestic and industrial usages are the major factors leading to water scarcity. Nigeria and the study area are blessed with abundant water resources including surface and groundwater, yet there is a palpable lack of adequate and safe potable water. Consequently, the populace resorts to private sources of water supply which has its negative externalities even though the effort seems laudable. Based on the above, the study examined the proliferation of private water supply, its challenges and socio-economic implications in Obio /Akpor local government area. The study adopted a cross-sectional survey, and data were collected with the use of both closed and open-ended questionnaire. It also involved the collection of the private borehole points with the use of a handheld global positioning system (GPS). Data were analyzed using the descriptive method of analysis and data presented in charts and tables. The result of the study showed that there were no specific distances maintained between borehole points, a good number of borehole locations were clustered in some parts of the study area. Also, distances between soakaway pits and borehole points were inadequate in some communities. Based on the prevalent minimum wage in the study area, both households that operate boreholes and those that buy water spent more. Some of the socio-economic implications of private provision of water supply include too much spending on water, creation of livelihoods for water vendors and vulnerability to waterborne disease such as typhoid since there is no minimum standard for borehole drilling and distance in the study area. The study recommended that the government should develop a private borehole drilling standard that would include the minimum distance that must be maintained between two boreholes on vertical and horizontal lines. Also, the activities of the private water vendors should be regulated, and operating license obtained before operating commercial boreholes. The study concluded thus, there should be a synergy between the private and public sector to ensure safe and affordable water supply since their activities cannot be undermined.
Respiratory Syncytial Virus Bronchiolitis Complicated by Necrotizing Enterocolitis: A Case Series
Authors: Arias Anita V. , Lucas Donald J. , Shafi Nadeem I.
Published: April 2021

In rare instances, severe respiratory syncytial virus (RSV) infections of the lower respiratory tract can cause life-threatening extrapulmonary complications. In this report, we describe 4 previously healthy, term and late-preterm infants admitted to the PICU with respiratory failure due to RSV bronchiolitis who developed necrotizing enterocolitis shortly after admission. All infants exhibited progressive abdominal distention, had typical radiographic findings, and developed simple or complex ascites. In addition to being managed with broad-spectrum antibiotics and bowel rest, 1 infant was treated with colon resection and ileostomy, 2 had peritoneal drainage procedures for ascites, and one of those later developed small bowel strictures treated with delayed resection and anastomosis. Three were discharged from the hospital without further complications; 1 died of septic shock. In this case series, we describe development of necrotizing enterocolitis in otherwise healthy neonates with severe RSV disease in the absence of traditional risk factors. We hypothesize that a dysregulated proinflammatory response associated with severe RSV disease may alter intestinal blood flow and compromise barriers to bacterial translocation. Enteral feeding intolerance, septic ileus, and/or complex ascites may represent important clinical corollaries in these patients.
Esports en tiempos de una pandemia global: oportunidades y futuros desafíos al transformar el juego en un deporte en Costa Rica
Authors: Rojas-Valverde Daniel , Fallas-Campos Andrea , Alpízar-Alpízar Mildred
Published: April 2021

En respuesta a la pandemia relacionada con COVID-19, el mundo ha sufrido una serie de cambios drásticos. Debido a ellos, se han anunciado aplazamientos y cancelaciones de múltiples grandes eventos anuales en los deportes, las cuales dan paso a nuevas alternativas digitales que responden a las disposiciones de aislamiento del gobierno. Los eSports se muestran como una alternativa en rápida evolución para mantener el espíritu deportivo y la pasión que los deportes provocan en la población en general. En Costa Rica, este deporte ha comenzado su crecimiento, tal como sucedió en todo el mundo, y se ha acelerado con una alta tasa de evolución. En este sentido, el país enfrenta grandes desafíos para su promoción, incluyendo la de futuros eventos, el desarrollo de profesionales y la creación de una estructura organizacional para su práctica óptima. Este manuscrito busca analizar cómo la pandemia global expone la necesidad de poner atención a las alternativas deportivas digitales como el eSport y los desafíos futuros que enfrenta Costa Rica al tratar de desarrollarlo de manera efectiva y eficiente.
Influence of heat stress on reproductive performance in dairy cows and opportunities to reduce its effects – a review
Authors: Penev T. , Dimov D. , Vasilev N. , Mitev J. , Miteva Tch. , Marinov I. , Stojnov M.
Published: April 2021

Abstract. The goal of this review is to consider and discuss the scientific literature related to the effect of heat stress (HS) on reproductive performance in dairy cows and opportunities to reduce its effects. The information in literature shows that the HS topic in dairy cows began to be discussed in the 1970s. As genetic progress related to productivity increases, the requirements for cows also increase, including for their reproduction performance. In the present review, a significant array of scientific papers is examined, as a result of which it is established that HS has a multifaceted effect on reproduction in dairy cows. The main role for the negative impact of HS is the effect of high ambient temperature on the hypothalamic-pituitary-ovarian axis. As a result, hormonal changes occur in the body of cows, which affect the behavior of cows in estrus, the development of follicles in the ovaries and the survival of the embryo in the uterus. These changes affect the main elements of cattle breeding such as length of days open interval, conception rate, number of inseminations required for conception. To mitigate the negative impact of HS on cows, methods have been developed for better estrus detection, for microclimate control, as well as for hormonal treatment of cows in order to increase reproductive performance. Although some progress has been made in each of the measures, HS still poses a serious reproductive problem for dairy cows, especially in the countries with warmer climates. This provokes the interest of many scientists around the world who seek to offer a solution/mitigation to this problem.
Seasonal variations in hematological profile of Holstein dairy cows as an indicator for physiological status assessment
Authors: Mekroud M. , Arzour-Lakehal N. , Ouchene-Khelifi N.A. , Ouchene N. , Titi A. , Mekroud A.
Published: April 2021

Abstract. This study aims to investigate, for the first time in Algeria, the effect of seasonal climatic changes on the hematological profile of Holstein dairy cows as an indicator for their physiological status assessment. The study was conducted between November 2018 and October 2019 and was performed on a lot of 14 dairy cows. Blood samples were collected quarterly during this study period. The data regarding seasonal changes in hematological parameters were not significant concerning red blood cell count (RBC), hemoglobin concentration (Hb) and mean corpuscular volume (MCV). However, variations were significant for hematocrit (HCT), mean corpuscular hemoglobin content (MCH), mean corpuscular hemoglobin concentration (MCHC) and blood platelets (PLT). The percentage of HCT was higher in autumn (27.99%) and spring (28.58%) compared to winter (26.52%) and summer (26.75%), (p<0.05). MCH, MCHC and PLT levels were higher in summer compared to the other seasons (p<0.05), (p<0.01) and (p<0.001), respectively. The highest number of WBC was generally observed in summer and autumn and the lowest in winter and spring (p<0.01). The ratio neutrophils/lymphocytes (N:L) was equal to 1.01, 0.79, 0.98 and 0.89 in autumn, winter, spring and summer, respectively of which this difference was not significant. This study might be helpful for providing base line information on the hematological profile of dairy cattle for the evaluation of physiological status.
INFLUENCE OF DIGITAL IMAGES PRELIMINARY NOISING ON STATISTICAL STEGDETECTORS PERFORMANCE
Authors: Progonov D. O.
Published: April 2021

Context. The problem of sensitive information protection during data transmission in communication systems was considered. The case of reliable detection of stego images formed according to advanced embedding methods was investigated. The object of research is digital images steganalysis of adaptive steganographic methods.

Objective. The goal of the work is performance analysis of statistical stegdetectors for adaptive embedding methods in case of preliminary noising of analyzed image with thermal and shot noises.

Method. The image pre-processing (calibration) method was proposed for improving stego-to-cover ratio for state-of-the-art adaptive embedding methods HUGO, MG and MiPOD. The method is aimed at amplifying negligible changes of cover image caused by message hiding with usage of Gaussian and Poisson noises. The former one is related to influence the thermal noise of chargecoupled device (CCD) based image sensor during data acquisition. The latter one is related to shot noise that originates from stochastic process of electron emission by photons hitting of CCD elements. During the research, parameters of thermal noise were estimated with two-dimensional Wiener filter, while sliding window of size 5·5 pixels was used for parameters evaluation for shot noise.

Results. The dependencies of detection error on cover image payload for advance HUGO, MG and MiPOD embedding methods were obtained. The results were presented for the case of image pre-noising with both Gaussian and Poisson noises, and varying of feature pre-processing methods.

Conclusions. The conducted experiments confirmed effectiveness of proposed approach for image calibration with Poisson noise. Obtained results allow us to recommend linearly transformed features to be used for improving stegdetector performance by natural image processing. The prospects for further research may include investigation usage of special noises, such as fractal noises, for improving stego-to-cover ratio for advanced embedding methods.