Manipulating vector solitons with super-sech pulse shapes

Theoretical simulations about manipulating vector solitons with super-sech pulse shapes are conducted based on an optical fiber system in this manuscript. By changing temporal pulses’ parameters when orthogonally polarized pulses have the same or different input central wavelengths, output modes in orthogonal directions will demonstrate different properties. When input orthogonal modes have the same central wavelength, “2+2” pseudo-high-order vector soliton can be generated when time delay is changed. While under the condition of different central wavelengths, orthogonal pulses with multiple peaks accompanied with two wavelengths can be achieved through varying projection angle, time delay or phase difference. Our simulations are helpful to the study of optical soliton dynamics in optical fiber system.

The Behaviour and Ecology of Austrolittorina antipodum and Austrolittorina cincta: Models for Marine Reserve Connectivity Studies

<p>Determining the magnitude of dispersal and connectivity between populations has important implications for marine conservation. Species with limited dispersal capabilities exhibit restricted gene flow leading to isolation and, ultimately, differentiated populations. In this ecological study I investigated the gastropods Austrolittorina antipodum (Philippi, 1847) and Austrolittorina cincta (Quoy and Gaimard, 1833) to determine how ecology and behaviour influence the dispersal and connectivity of these species. The aim of this study was to determine population size and structure, settlement, fecundity, and adult movement rates. Methodologies included: population surveys, deployment of settlement pads and adult density manipulations, dissections, and a tagging study. These elements of a species ecology and behaviour can enhance or restrict population connectivity by: cohort partitioning resulting from habitat requirements, fluctuating settlement due to variable larval mortality or adult densities impacting dispersal, skewed sex ratios and effective populations sizes altering larval production, and adult movement leading to behavioural isolation or facilitating gene flow, along with other possible effects. Population surveys revealed both species had a Vermeij (1972) "type 1 distribution" (shell size increasing from the low to high shore), with the highest density of individuals on the low shore and the majority of mature adults on the high shore. Overall, A. antipodum was 16 times more abundant than A. cincta. Shifts to a smaller mean size of both species, along all shore heights following periods of peak settlement indicates settlers are potentially triggering competitive interactions or ontogenetic migrations in other cohorts.Settlement surveys revealed that peak settlement for Austrolittorina spp. was from February to April, declining at the beginning of March. Multiple peaks in settlement may act as a buffer limiting the potential of stochastic events to hinder dispersal during reproductive seasons. Settlement rates were not affected by adult density in control treatments; however, settlement was higher on pads deployed within adult populations compared to pads deployed adjacent to adult populations, suggesting the presences of adults has some effect on settlement. Fecundity results revealed A. antipodum to have more mature females than A. cincta, with males of both species reaching sexual maturity before females. Sex ratios of both species were skewed towards more females, with effective population sizes that included approximately 88% of each species population. A. antipodum’s larger population may be due to variation between the species' demographics, such as the distribution of mature females and juveniles leading to greater spawning success and juvenile survivorship. Tagging transplant/translocation experiments used to examine movement revealed that both species traveled similar distances. On average A. antipodum traveled 24.1m (±23.5m) and A. cincta traveled 18.7m (±16m) in eight months. There was no evidence of behavioural isolation occurring between low and high shore individuals. The wide ranging movements of adults indicated adults have the potential to maintain population connectivity on small scales. The findings of this study suggest both species facilitate dispersal with multiple peaks in settlement, large effective populations, and high adult mobility. Behavioural variation between the species appears to affect population connectivity, with the distribution of A. antipodum demographics potentially enhancing connectivity.</p>

The Behaviour and Ecology of Austrolittorina antipodum and Austrolittorina cincta: Models for Marine Reserve Connectivity Studies

<p>Determining the magnitude of dispersal and connectivity between populations has important implications for marine conservation. Species with limited dispersal capabilities exhibit restricted gene flow leading to isolation and, ultimately, differentiated populations. In this ecological study I investigated the gastropods Austrolittorina antipodum (Philippi, 1847) and Austrolittorina cincta (Quoy and Gaimard, 1833) to determine how ecology and behaviour influence the dispersal and connectivity of these species. The aim of this study was to determine population size and structure, settlement, fecundity, and adult movement rates. Methodologies included: population surveys, deployment of settlement pads and adult density manipulations, dissections, and a tagging study. These elements of a species ecology and behaviour can enhance or restrict population connectivity by: cohort partitioning resulting from habitat requirements, fluctuating settlement due to variable larval mortality or adult densities impacting dispersal, skewed sex ratios and effective populations sizes altering larval production, and adult movement leading to behavioural isolation or facilitating gene flow, along with other possible effects. Population surveys revealed both species had a Vermeij (1972) "type 1 distribution" (shell size increasing from the low to high shore), with the highest density of individuals on the low shore and the majority of mature adults on the high shore. Overall, A. antipodum was 16 times more abundant than A. cincta. Shifts to a smaller mean size of both species, along all shore heights following periods of peak settlement indicates settlers are potentially triggering competitive interactions or ontogenetic migrations in other cohorts.Settlement surveys revealed that peak settlement for Austrolittorina spp. was from February to April, declining at the beginning of March. Multiple peaks in settlement may act as a buffer limiting the potential of stochastic events to hinder dispersal during reproductive seasons. Settlement rates were not affected by adult density in control treatments; however, settlement was higher on pads deployed within adult populations compared to pads deployed adjacent to adult populations, suggesting the presences of adults has some effect on settlement. Fecundity results revealed A. antipodum to have more mature females than A. cincta, with males of both species reaching sexual maturity before females. Sex ratios of both species were skewed towards more females, with effective population sizes that included approximately 88% of each species population. A. antipodum’s larger population may be due to variation between the species' demographics, such as the distribution of mature females and juveniles leading to greater spawning success and juvenile survivorship. Tagging transplant/translocation experiments used to examine movement revealed that both species traveled similar distances. On average A. antipodum traveled 24.1m (±23.5m) and A. cincta traveled 18.7m (±16m) in eight months. There was no evidence of behavioural isolation occurring between low and high shore individuals. The wide ranging movements of adults indicated adults have the potential to maintain population connectivity on small scales. The findings of this study suggest both species facilitate dispersal with multiple peaks in settlement, large effective populations, and high adult mobility. Behavioural variation between the species appears to affect population connectivity, with the distribution of A. antipodum demographics potentially enhancing connectivity.</p>

Data analysis of COVID-19 wave peaks in relation to latitude and temperature for multiple nations

It was observed that the multiple peaks of coronavirus disease 19 (COVID 19) appeared in different seasons in different countries. There were countries where the COVID-19 peak occurred during extremely low temperatures, such as Norway, Canada and on the other hand there were countries with high-temperature ranges such as Brazil, India, UAE. Most of the high-latitude countries received their outbreak in winter and most of the countries near the equator mark the outbreak during the summer. Most of the biological organisms have their growth dependent on the temperature, and hence we explored that if there is any relation of temperature versus COVID-19 outbreak in the particular country. It was also seen that people are not behaving differently during the peak of the COVID-19 wave, hence it was important to know whether the COVID-19 virus has evolved or the global temperature variation caused these multiple peaks. This work focuses on finding the effect of temperature variation on the COVID-19 outbreak. We used Levenberg Marquardt technique to find the correlation between the temperature at which COVID-19 outbreak peaks and the latitude of the particular country. We found that between the temperature range of 14 Degree C to 20 Degree C spread of the COVID-19 is minimal. Based on our results we can also say that the COVID-19 outbreak is seen in lower temperature (0 Degree C to 13 Degree C) ranges as well as in the higher temperature ranges (21 Degree C to 35 Degree C). The current data analysis will help the authorities to manage their resources in advance to prepare for any further outbreaks that might occur in the COVID-19 or even in the next pandemic.

‘Good’ and ‘Bad’ deaths during the COVID-19 pandemic: insights from a rapid qualitative study

Dealing with excess death in the context of the COVID-19 pandemic has thrown the question of a ‘good or bad death’ into sharp relief as countries across the globe have grappled with multiple peaks of cases and mortality; and communities mourn those lost. In the UK, these challenges have included the fact that mortality has adversely affected minority communities. Corpse disposal and social distancing guidelines do not allow a process of mourning in which families and communities can be involved in the dying process. This study aimed to examine the main concerns of faith and non-faith communities across the UK in relation to death in the context of the COVID-19 pandemic. The research team used rapid ethnographic methods to examine the adaptations to the dying process prior to hospital admission, during admission, during the disposal and release of the body, during funerals and mourning. The study revealed that communities were experiencing collective loss, were making necessary adaptations to rituals that surrounded death, dying and mourning and would benefit from clear and compassionate communication and consultation with authorities.

Differential mutational profile of SARS-CoV-2 proteins across deceased and asymptomatic patients

The SARS-CoV-2 infection spread at an alarming rate with many places showed multiple peaks in incidence. Present study involves a total of 332 SARS-CoV-2 sequences from 114 Asymptomatic and 218 Deceased patients from twenty-one different countries. The mining of mutations was done using the GISAID CoVSurver (www.gisaid.org/epiflu-applications/covsurver-mutations-app) with the reference sequence ‘hCoV-19/Wuhan/WIV04/2019’ present in NCBI with Accession number NC-045512.2. The impact of the mutations on SARS-CoV-2 proteins mutation was predicted using PredictSNP1(loschmidt.chemi.muni.cz/predictsnp1) which is a meta-server integrating six predictor tools: SIFT, PhD-SNP, PolyPhen-1, PolyPhen-2, MAPP and SNAP. The iStable integrated server (predictor.nchu.edu.tw/iStable) was used to predict shifts in the protein stability due to mutations. A total of 372 variants were observed in the 332 SARS-CoV-2 sequences with several variants incident in multiple patients accounting for a total of 1596 incidences. Asymptomatic and Deceased specific mutants constituted 32% and 62% of the repertoire respectively indicating their exclusivity. However, the most prevalent mutations were those present in both. Though some parts of the genome are more variable than others but there was clear difference between incidence and prevalence. NSP3 with 68 variants had total occurrence of only 105 whereas Spike protein had 346 occurrences with just 66 variants. For Deleterious variants, NSP3 had the highest incidence of 25 followed by NSP2 (16), ORF3a (14) and N (14). Spike protein had just 7 Deleterious variants out of 66. Deceased patients have more Deleterious than Neutral variants as compared to the symptomatic ones. Further, it appears that the Deleterious variants which decrease protein stability are more significant in pathogenicity of SARS-CoV-2.

Numerical and Theoretical Investigation on the Origin of the Multiple Peaks of the H/V Ratio Curve

&lt;p&gt;Despite the popularity of the horizontal to vertical spectral ratio (HVSR) method in site effect studies, the origin of the H/V peaks has been controversial since this method was proposed. Many previous studies mainly focused on the explanation of the first or single peak of the H/V ratio, trying to distinguish between the two hypotheses &amp;#8212; the S-wave resonance and ellipticity of Rayleigh wave. However, it is common both in numerical simulations and practical experiments that the H/V ratio exhibits multiple peaks, which is essential to explore the origin of the H/V peaks.&lt;/p&gt;&lt;p&gt;The cause for the multiple H/V peaks has not been clearly figured out, and once was simply explained as the result of multi subsurface layers. Therefore, we adopted numerical method to simulate the ambient noise in various layered half-space models and calculated the H/V ratio curves for further comparisons. The peak frequencies of the H/V curves accord well with the theoretical frequencies of S-wave resonance in two-layer models, whose frequencies only depend on the S wave velocity and the thickness of the subsurface layer. The same is true for models with varying model parameters. Besides, the theoretical formula of the S-wave resonance in multiple-layer models is proposed and then supported by numerical investigations as in the cases of two-layer models. We also extended the S-wave resonance to P-wave resonance and found that its theoretical frequencies fit well with the V/H peaks, which could be an evidence to support the S-wave resonance theory from a new perspective. By contrast, there are obvious differences between the higher orders of the H/V ratio peaks and the higher orders of Rayleigh wave ellipticity curves both in two-layer and multiple-layer models. The Rayleigh wave ellipticity curves are found to be sensitive to the Poisson&amp;#8217;s ratio and the thickness of the subsurface layer, so the variation of the P wave velocity can affect the peak frequencies of the Rayleigh wave ellipticity curves while the H/V peaks show slight change. The Rayleigh wave ellipticity theory is thus proved to be inappropriate for the explanation of the multiple H/V peaks, while the possible effects of the Rayleigh wave on the fundamental H/V peak still cannot be excluded.&lt;/p&gt;&lt;p&gt;Based on the analyses above, we proposed a new evidence to support the claim that the peak frequencies of the H/V ratio curve, except the fundamental peaks, are caused by S-wave resonance. The relationship between the P-wave resonance and the V/H peaks may also find further application.&lt;/p&gt;

Effect of population migration and punctuated lockdown on the spread of infectious diseases

One of the critical measures to control infectious diseases is a lockdown. Once past the lockdown stage in many parts of the world, the crucial question now concerns the effects of relaxing the lockdown and finding the best ways to implement further lockdown(s), if required, to control the spread. With the relaxation of lockdown, people migrate to different cities and enhance the spread of the disease. This work presents the population migration model for n-cities and applies the model for migration between two and three cities. The reproduction number is calculated, and the effect of the migration rate is analyzed. A punctuated lockdown is implemented to simulate a protocol of repeated lockdowns that limits the resurgence of infections. A damped oscillatory behavior is observed with multiple peaks over a period.

The Application of Radon Measurement In the Active Fault Detection of Xiadian Fault

The Xiadian active fault is one of the most important seismological faults in the vicinity of Beijing-Tianjin-Hebei region. This paper mainly focuses on the geochemical characteristics of the fault to unveil and evaluate its activity. Via the application of soil gaseous radon measurement, a detailed field study at Qixinzhuang segment of Xiadian fault is proposed. Based on all the radon impulse value we acquired of 3 profiles in the study area. We plotted the radon impulse trend chart of 3 profiles, analyzed anomaly distribution of soil gaseous radon and discussed the scale and activity of the Xiadian fault. The radon multiple-peaks anomaly of Qixinzhaung segemnt demonstrates the hidden faults underground exist.