COVID-19: The Conjunction of Events Leading to the Coronavirus Pandemic and Lessons to Learn for Future Threats

Originally identified in December 2019 in Wuhan, China, SARS-CoV-2 has become a pandemic owing to a long period of incubation, a high number of asymptomatic cases, and high international mobility. Here we consider the unique conjunction of events that allowed this new coronavirus to emerge and create a pandemic. We urge governments to learn from SARS and COVID-19 and to implement preparedness for pandemics to come

Emergence of Bat-Related Betacoronaviruses: Hazard and Risks

The current Coronavirus Disease 2019 (COVID-19) pandemic, with more than 111 million reported cases and 2,500,000 deaths worldwide (mortality rate currently estimated at 2.2%), is a stark reminder that coronaviruses (CoV)-induced diseases remain a major threat to humanity. COVID-19 is only the latest case of betacoronavirus (β-CoV) epidemics/pandemics. In the last 20 years, two deadly CoV epidemics, Severe Acute Respiratory Syndrome (SARS; fatality rate 9.6%) and Middle East Respiratory Syndrome (MERS; fatality rate 34.7%), plus the emergence of HCoV-HKU1 which causes the winter common cold (fatality rate 0.5%), were already a source of public health concern. Betacoronaviruses can also be a threat for livestock, as evidenced by the Swine Acute Diarrhea Syndrome (SADS) epizootic in pigs. These repeated outbreaks of β-CoV-induced diseases raise the question of the dynamic of propagation of this group of viruses in wildlife and human ecosystems. SARS-CoV, SARS-CoV-2, and HCoV-HKU1 emerged in Asia, strongly suggesting the existence of a regional hot spot for emergence. However, there might be other regional hot spots, as seen with MERS-CoV, which emerged in the Arabian Peninsula. β-CoVs responsible for human respiratory infections are closely related to bat-borne viruses. Bats are present worldwide and their level of infection with CoVs is very high on all continents. However, there is as yet no evidence of direct bat-to-human coronavirus infection. Transmission of β-CoV to humans is considered to occur accidentally through contact with susceptible intermediate animal species. This zoonotic emergence is a complex process involving not only bats, wildlife and natural ecosystems, but also many anthropogenic and societal aspects. Here, we try to understand why only few hot spots of β-CoV emergence have been identified despite worldwide bats and bat-borne β-CoV distribution. In this work, we analyze and compare the natural and anthropogenic environments associated with the emergence of β-CoV and outline conserved features likely to create favorable conditions for a new epidemic. We suggest monitoring South and East Africa as well as South America as these regions bring together many of the conditions that could make them future hot spots

Wavelength-switchable L-band fiber laser assisted by random reflectors

A wavelength-switchable L-band erbium-doped fiber laser (EDFL) assisted by an artificially controlled backscattering (ACB) fiber reflector is here presented. This random reflector was inscribed by femtosecond (fs) laser direct writing on the axial axis of a multimode fiber with 50 um core and 125 um cladding with a length of 17 mm. This microstructure was placed inside a surgical syringe to be positioned in the center of a high-precision rotation mount to accurately control its angle of rotation. Only by rotating this mount, three different output spectra were obtained: a single wavelength lasing centered at 1574.75 nm, a dual wavelength lasing centered at 1574.75 nm and 1575.75 nm, and a single wavelength lasing centered at 1575.5 nm. All of them showed an optical signal-to-noise ratio (OSNR) of around 60 dB when pumped at 300 mW.This work was financed by the program “José Castillejo para estancias de movilidad en el extranjero de jóvenes doctores”, funded by the Ministerio de Universidades of Spain (reference CAS21/00351); the Spanish AEI projects PID2019-107270RB, funded by MCIN/AEI/10.13039/501100011033 and FEDER “A way to make Europe”, and projects PDC2021-121172 and TED2021-130378B funded by MCIN/ AEI/10.13039/501100011033 and European Union “Next generation EU”/PTR. Finally, the work was also founded by the Ministerio de Educación, Cultura y Deporte of Spain (PhD grant FPU2018/02797)

C and L band fiber lasers enhanced by ultrafast laser inscribed artificial backscatter reflectors

This letter presents an experimental comparison between two linear-cavity erbium-doped fiber lasers (EDFL) assisted by two different artificial backscatter fiber-based reflectors. Both reflectors were inscribed by femtosecond laser direct writing, one of them within a single-mode fiber (SMF) and the other one within a multi-mode fiber (MMF). Although the erbium-doped fiber amplifier (EDFA) used in both structures was the same and both reflectors were manufactured under the same parameters, the reflection spectrum of each was clearly different due to their different physical properties. The first linear-cavity EDFL, consisting of an SMF-based reflector with 9µm core and 125µm cladding, resulted in a single laser emission line located in the C-band and centered at 1564.4 nm, exhibiting an optical signal-to-noise ratio (OSNR) of 52dB when pumped at 100mW. On the other hand, a single laser emission line with a similar OSNR but in L-band (centered at 1574.5nm) was obtained when using an MMF-based reflector with 50µm core and 125µm cladding.Ministerio de Educación, Cultura y Deporte (PhD grant FPU2018/02797); European Commission (Next generation EU/PTR); FEDER (A way to make Europe); MCIN/AEI/10.13039/501100011033 (PDC2021-121172-C21, PID2019-107270RB)

Functional Massage of the Teres Major Muscle in Patients with Subacromial Impingement Syndrome. A Randomized Controlled Case Series Study.

Objective: the purpose of the present study was to analyze the concurrent validity and reliability of a force platform clinical COBS Feedback® for the estimation of the height of vertical jumps. Design: a cross-sectional correlational and comparative study. Setting: University Human Movement and Physiotherapy Laboratory. Participants: healthy university students (14 female and 13 male) aged between 18 and 25 years old (mean = 20.074 ±1.542). Main Outcome Measures: vertical jump heights, technical error and grade of agreement between methods of measurement. Results: after the 27 subjects performed a total of 135 vertical jumps on COBS Feedback®platform while simultaneously being recorded with a high-speed camera-based method, the intraclass correlation coefficient showed an almost perfect concordance between the two methods (ICC = 0.916, CI95%= 0.882 to 0.940, p<0.001). The technical error of the COBS Feedback® against HSC-Kinovea video analysis was at 0.310±0.223m, being higher in males than in females (t= -2.822, CI95%: -0.376 to -0.574, p=0.001). Conclusions: the COBS Feedback® method provided a valid measurement of the flight times for estimate the vertical jump height as a number of well-known tests and devices.Aims: Subacromial impingement syndrome is the most common shoulder condition. Myofascial trigger points in teres major muscle can be associated with this syndrome. Our objective is to determine whether adding manual therapy specifically for teres major trigger points can produce better results in these patients. Study Design: Randomized controlled case series. Place and Duration of Study: Public Primary Care Center in the Spanish National Health System (Cornellà de Llobregat - Barcelona) and the FREMAP Mutual Society for Work-related Injuries and Occupational Illness (Arnedo - La Rioja), between January and March 2014. Methodology: Fifty-eight people were recruited but 8 subjects were lost during the follow-up period. The sample consisted of 50 patients (17 male and 33 female, age range 23-80 years) randomly assigned to one of two groups: the intervention group or the control group. Both groups received a protocolized physical therapy treatment, while the intervention group also received manual therapy for teres major trigger points. Results: Pain intensity (p=.01) and function (p=.01) showed significant improvement in the control group, whereas pain intensity (p=.01), function (p=.01) and active range of motion (p=.01) showed significant improvement in the intervention group. Between-group differences were statistically significant for abduction (p=.01), extension (p=.02) and lateral rotation (p=.02), and clinically significant (Cohen’s d) for function, flexion, extension, lateral rotation and abduction. Conclusion: Although our findings must be considered as preliminary, they suggest that adding manual therapy to treat teres major trigger points achieves better results in the glenohumeral range of motion

Single-longitudinal mode laser structure based on a very narrow filtering technique

A narrow filtering technique based on the spectral overlapping of two uniform FBGs and applied to obtain a Single Longitudinal Mode (SLM) laser is proposed and demonstrated in this work. The two FBGs are spectrally detuned to reduce their coincident reflection response narrowing the equivalent filter bandwidth. A proof-of-concept linear laser has been built and tested exhibiting SLM operation even with temperature and strain variations.The authors are grateful to the Spanish government project TEC2010-20224-C02, to the Spanish Ministry of Education and Culture, and to the grant AP2009-1403