bluuebunny/crossref_metadata_2025 huggingface dataset:
The photon vortex beam in rotating medium
Authors: Wei Jianye , Jia Wei , Peng Xubiao , Zhao Qing , Ge Molin
Published: July 2020

In this paper, we demonstrate that there are vortex beam solutions for the photon in the rotating medium. By constructing the photon wave function with Riemann–Silberstein vector, we derive the dynamic equation of the photon in moving medium from the Maxwell equations and the non-relativistic Minkowski relations. In case of the stationary state, the dynamic equation of the photon can be written as a Dirac-like equation, where the velocity of the medium plays the role of a vector potential. By giving the medium different forms of rotating velocity fields, we obtain different vortex beam solutions of the photon, such as the diffracting and non-diffracting Laguerre–Gaussian (LG) beam solutions via proper approximations. For the diffracting LG beam solution, we acquire a new term arising from the medium rotation that can change the Gouy phase, and then accordingly predict the rotation behavior of the photon interference pattern. In addition, the rotation of the medium can lead to the change of the relative intensity distribution of the interference pattern. Furthermore, our theory predicts the existence of the Landau levels of transverse photon energy in the nondiffracting LG beam solution.
Low-dimensional vanadium dioxide nanomaterials: fabrication, properties and applications
Authors: Liu Chang , Wang Yang , Tian Ziao , Mei Yongfeng
Published: July 2020

Vanadium dioxide (VO2) receives a great deal of attention because of its intriguing properties of metal-insulator transition and its wide applications in electronics, optoelecronics, smart coatings, and so on. To further enhance the performance of their applications, low dimensional VO2 nanomaterials, such as nanobeams and nanomembranes, have become a research hotspot due to their structural advantages, including large specific surface area, convenient miniaturization, light weight, and softness. In this paper, the recent studies of low dimensional VO2 nanomaterials are discussed, focusing on their preparation methods, properties, and applications, as well as the existing challenges and future prospectives.
The imaginary part of the high-harmonic cutoff
Authors: Pisanty Emilio , Ciappina Marcelo F , Lewenstein Maciej
Published: July 2020

High-harmonic generation—the emission of high-frequency radiation by the ionization and subsequent recombination of an atomic electron driven by a strong laser field—is widely understood using a quasiclassical trajectory formalism, derived from a saddle-point approximation, where each saddle corresponds to a complex-valued trajectory whose recombination contributes to the harmonic emission. However, the classification of these saddle points into individual quantum orbits remains a high-friction part of the formalism. Here we present a scheme to classify these trajectories, based on a natural identification of the (complex) time that corresponds to the harmonic cutoff. This identification also provides a natural complex value for the cutoff energy, whose imaginary part controls the strength of quantum-path interference between the quantum orbits that meet at the cutoff. Our construction gives an efficient method to evaluate the location and brightness of the cutoff for a wide class of driver waveforms by solving a single saddle-point equation. It also allows us to explore the intricate topologies of the Riemann surfaces formed by the quantum orbits induced by nontrivial waveforms.
Notions of Stein spaces in non-Archimedean geometry
Authors: Maculan Marco , Poineau Jérôme
Published: July 2020

Let

k
k

be a non-Archimedean complete valued field and let

X
X

be a

k
k

-analytic space in the sense of Berkovich. In this note, we prove the equivalence between three properties: (1) for every complete valued extension 

k
′

k’

of 

k
k

, every coherent sheaf on 

X

×

k

k
′

X \times _{k} k’

is acyclic; (2)

X
X

is Stein in the sense of complex geometry (holomorphically separated, holomorphically convex), and higher cohomology groups of the structure sheaf vanish (this latter hypothesis is crucial if, for instance,

X
X

is compact); (3)

X
X

admits a suitable exhaustion by compact analytic domains considered by Liu in his counter-example to the cohomological criterion for affinoidicity.

When 

X
X

has no boundary the characterization is simpler: in (2) the vanishing of higher cohomology groups of the structure sheaf is no longer needed, so that we recover the usual notion of Stein space in complex geometry; in (3) the domains considered by Liu can be replaced by affinoid domains, which leads us back to Kiehl’s definition of Stein space.
Evidence for pollination ecotypes in the African cycadEncephalartos ghellinckii(Zamiaceae)
Authors: Suinyuy Terence N , Johnson Steven D
Published: July 2020

Geographical variation in pollinator assemblages can result in divergent selective pressures and consequently drive the evolution of phenotypically distinct pollination ecotypes. Intraspecific divergence in pollination systems is well known among angiosperms, but is poorly studied among gymnosperms, often considered a relictual group not undergoing recent radiations. We investigated whether geographical divergence in the chemistry of volatiles emitted by cones of the cycad Encephalartos ghellinckii can be linked with functions for attracting different pollinators. We tested the pollination effectiveness of different insects in terms of deposition of fluorescent dye on micropyles and investigated whether daily fluctuations in cone temperature are correlated with insect pollinator activity. We also performed field bioassays to test the responses of insects to key volatiles and laboratory y-maze experiments to determine whether insects discriminate among cones of the two forms. Experiments confirmed that the beetles Metacucujus goodei and Erotylidae sp. nov. are the most effective pollinators of the mountain and lowland forms, respectively. A peak in cone temperatures in the afternoon was associated with extensive movement of insects among cones of mountain plants, but only limited movement of insects among cones of lowland plants. In field bioassays, Metacucujus goodei beetles were attracted mainly to (3E)-1,3-octadiene, a dominant component of the scent of mountain plants, whereas Erotylidae sp. nov. responded to camphene, a dominant component of the scent of lowland plants. When offered a choice, beetles preferred cones from the local population over those from a different population. The results suggest that E. ghellinckii consists of two pollination ecotypes with modifications in scent chemistry being correlated with an apparent shift between different pollinators. The relationship between thermogenesis and pollinator activities varies between ecotypes, with mountain plants showing a push–pull type of system and the lowland plants a system in which insects depart from cones with declining quality. This study highlights the role of insect pollinators in driving the evolution of cycads and the importance of thermogenesis and volatile emissions for mediating some beetle pollination systems.
Performance of three iGrav superconducting gravity meters before and after transport to remote monitoring sites
Authors: Schäfer Florian , Jousset Philippe , Güntner Andreas , Erbas Kemal , Hinderer Jacques , Rosat Séverine , Voigt Christian , Schöne Tilo , Warburton Richard
Published: July 2020

High spatial and temporal resolution of gravity observations allows quantifying and understanding mass changes in volcanoes, geothermal or other complex geosystems. For this purpose, accurate gravity meters are required. However, transport of the gravity meters to remote study areas may affect the instrument's performance. In this work, we analyse the continuous measurements of three iGrav superconducting gravity meters (iGrav006, iGrav015 and iGrav032), before and after transport between different monitoring sites. For 4 months, we performed comparison measurements in a gravimetric observatory (J9, Strasbourg) where the three iGravs were subjected to the same environmental conditions. Subsequently, we transported them to Þeistareykir, a remote geothermal field in North Iceland. We examine the stability of three instrumental parameters: the calibration factors, noise levels and drift behaviour. For determining the calibration factor of each instrument, we used three methods: First, we performed relative calibration using side-by-side measurements with an observatory gravity meter (iOSG023) at J9. Secondly, we performed absolute calibration by comparing iGrav data and absolute gravity measurements (FG5#206) at J9 and Þeistareykir. Thirdly, we also developed an alternative method, based on intercomparison between pairs of iGravs to check the stability of relative calibration before and after transport to Iceland. The results show that observed changes of the relative calibration factors by transport were less than or equal to 0.01 per cent. Instrumental noise levels were similar before and after transport, whereas periods of high environmental noise at the Icelandic site limited the stability of the absolute calibration measurements, with uncertainties above 0.64 per cent (6 nm s–2 V–1). The initial transient drift of the iGravs was monotonically decreasing and seemed to be unaffected by transport when the 4K operating temperatures were maintained. However, it turned out that this cold transport (at 4 K) or sensor preparation procedures before transport may cause a change in the long-term quasi-linear drift rates (e.g. iGrav015 and iGrav032) and they had to be determined again after transport by absolute gravity measurements.
Invasive Mucinous Neoplasm of the Appendix Masquerading as Recurrent Urinary Tract Infections: a Case Report
Authors: Ciampa Maeghan L , Chohonis James P , Otto Richard S , Franklin Benjamin T
Published: July 2020

We report on a case of a healthy male patient who was referred to Urology for recurrent persistent urinary tract infections. Investigation revealed a large intraabdominal inflammatory collection abutting the cecum and bladder suspicious for ruptured appendicitis and colovesical fistula. He was taken to the operating room for exploratory laparotomy with General Surgery and Urology and found to have a ruptured appendix secondary to mucinous appendiceal neoplasm with invasion into the cecum and the bladder wall. He then underwent systemic chemotherapy followed by hyperthermic intraperitoneal chemotherapy. He is well with stable right lower quadrant inflammatory collection and without evidence of metastatic disease 22 months following initial surgery. This case presents a rare presentation of a rare disease process that is easy to misdiagnose or be delayed in diagnosis because of its vague and often varied presentation.
Challenges for China's medical education in the coming post-COVID-19 era
Authors: Shao Li , Zhao Weijie
Published: July 2020

The year of 2020 has been overshadowed by the COVID-19 pandemic. Medical workers throughout China have played critical roles in battling severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) and saving lives. The whole of society has now fully realized the significance of medical workers and many began to think about medical education in China: How can we further improve medical education for the next generation of clinicians, medical scientists, nurses, public-health workers and administrators related to medical care, so that they are well prepared to meet societal needs for medical care in the ever-changing world? In this panel discussion, medical-education experts from several prominent medical schools in China gathered to discuss the reform and future development of China's medical education.

Xiang Chen

President of Xiangya School of Medicine, Vice President of Central South University, Changsha, China

Baorong Chi

Professor of Norman Bethune Health Science Center of Jilin University, Changchun, China

Yiqun Hu

Vice Chancellor of Shanghai Jiao Tong University School of Medicine, Shanghai, China

Yang Ke

Professor of Peking University Health Science Center, former Vice President of Peking University, Beijing, China

Ming Kuang

Vice President of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China

Mengfeng Li

President of Southern Medical University, Guangzhou, China

Hongbing Shen

President of Nanjing Medical University, Nanjing, China

Xuehong Wan

Professor of West China Medical Center, Vice President of Graduate School of Sichuan University, Chengdu, China

Hong Yan

President of Xi’an Jiaotong University Health Science Center, Vice President of Xi’an Jiaotong University, Xi’an, China

Guoqiang Chen (Chair)

Chancellor of Shanghai Jiao Tong University School of Medicine, Vice President of Shanghai Jiao Tong University, Shanghai, China
Surgical Treatment of Complete Foot Drop: Partial Tibial Nerve Transfer to the Motor Branch of the Tibialis Anterior: 2-Dimensional Operative Video
Authors: Protopsaltis Themistocles S , Parekh Yesha H
Published: July 2020

This video will be demonstrating the surgical treatment of complete foot drop with partial tibial nerve transfer to the motor branch of the tibialis anterior. Foot drop occurs when there is injury to the deep peroneal nerve that results in the paralysis of the tibialis anterior muscle and subsequent loss of ankle dorsiflexion.
1-5
The patient who is the subject of this video is a 27-yr-old female with a 6-mo history of foot drop. She presented with complete loss of ankle dorsiflexion and great toe extension due to traumatic fall on her left knee while running. Upon physical examination, she had all the features of complete foot drop with loss of ankle dorsiflexion and ankle eversion. She also had decreased sensation to light touch over left dorsal foot, left great toe, and left lateral lower leg. The patient has consented to this procedure. The partial tibial nerve transfer to the motor branch of tibialis anterior muscle is the preferred treatment option for foot drop as it restores ankle dorsiflexion with minimal donor site complications. At 12 mo postsurgery, she has regained 4/5 for ankle dorsiflexion on motor testing compared to the 0/5 she had preoperatively.
Optimal Automatic Stabilizers
Authors: McKay Alisdair , Reis Ricardo
Published: July 2020

Should the generosity of unemployment benefits and the progressivity of income taxes depend on the presence of business cycles? This paper proposes a tractable model where there is a role for social insurance against uninsurable shocks to income and unemployment, as well as business cycles that are inefficient due to the presence of matching frictions and nominal rigidities. We derive an augmented Baily–Chetty formula showing that the optimal generosity of the social insurance system depends on a macroeconomic stabilization term. This term pushes for an increase in generosity when the level of economic activity is more responsive to social programmes in recessions than in booms. A calibration to the US economy shows that taking concerns for macroeconomic stabilization into account substantially raises the optimal unemployment insurance replacement rate but has a negligible impact on the optimal progressivity of the income tax. More generally, the role of social insurance programmes as automatic stabilizers affects their optimal design.
Only Time Will Tell: A Theory of Deferred Compensation
Authors: Hoffmann Florian , Inderst Roman , Opp Marcus
Published: July 2020

This article characterizes optimal compensation contracts in principal-agent settings in which the consequences of the agent’s action are only observed over time. The optimal timing of pay trades off the costs of deferred compensation arising from the agent’s relative impatience and potential consumption smoothing needs against the benefit of exploiting additional informative signals. By capturing this information benefit of deferral in terms of the likelihood ratio dynamics, our characterization covers general signal processes in a unified setting. With bilateral risk neutrality and agent limited liability, optimal contracts are high-powered and stipulate at most two payout dates. If the agent is additionally risk-averse, payouts are contingent on performance exceeding a hurdle that is increasing over time. We obtain clear-cut predictions on how the duration of optimal compensation depends on the nature of information arrival as well as agent characteristics and derive implications for the maturity structure of securities in financial contracting settings.
“Sometimes you have to pop them”: Conflict and Meaning-Making in a Parenting Class
Authors: Cucchiara Maia
Published: July 2020

Parenting education is designed to address problems associated with childhood poverty, but such programs have had limited success. This ethnographic study of a parenting class serving low-income African American mothers examines tensions between parents and instructors over the use of physical force in disciplining children or in resolving conflicts more broadly. The article uses the concept of cultural frames to analyze how parents and instructors understood the issues at stake, showing significant differences between the frame the instructors used (discouraging all forms of force) and that of the parents (who saw force as sometimes necessary and effective). The instructors' therapeutic frame positioned children as vulnerable and prioritized self-esteem and positive relationships, and it did not resonate with parents, whose protective frame emphasized their responsibility to keep children safe in a dangerous world. This study examines interactions between parents and instructors to show that when frames come into conflict in social settings, collective affirmation of a particular frame can be a source of resistance and solidarity, thus raising questions about the potential of anti-poverty interventions that do not pay attention to context or meaning making.
National Institutes of Health social and behavioral research in response to the SARS-CoV2 Pandemic
Authors: Riley William T , Borja Susan E , Hooper Monica Webb , Lei Ming , Spotts Erica L , Phillips John W R , Gordon Joshua A , Hodes Richard J , Lauer Michael S , Schwetz Tara A , Perez-Stable Eliseo
Published: July 2020

The COVID-19 pandemic has been mitigated primarily using social and behavioral intervention strategies, and these strategies have social and economic impacts, as well as potential downstream health impacts that require further study. Digital and community-based interventions are being increasingly relied upon to address these health impacts and bridge the gap in health care access despite insufficient research of these interventions as a replacement for, not an adjunct to, in-person clinical care. As SARS-CoV-2 testing expands, research on encouraging uptake and appropriate interpretation of these test results is needed. All of these issues are disproportionately impacting underserved, vulnerable, and health disparities populations. This commentary describes the various initiatives of the National Institutes of Health to address these social, behavioral, economic, and health disparities impacts of the pandemic, the findings from which can improve our response to the current pandemic and prepare us better for future infectious disease outbreaks.
Tapping Away at a Misleading Meta-analysis
Authors: Spielmans Glen I. , Rosen Gerald M. , Spence-Sing Tess
Published: July 2020

Church et al.'s meta-analysis of three studies claimed to support the specificity of acupoint tapping as a therapeutic technique in the treatment of mental health problems. However, our critical analysis found substantial methodological problems and inaccurate statistical analyses, which render their results invalid. Specifically, 1) two included studies did not include participants with documented mental health problems; 2) two included studies did not specifically isolate the effect of acupoint tapping; 3) clear rationales for selected measures were not provided; 4) comparison groups were not bona fide therapies; 5) researcher and therapist allegiances were not controlled; and 6) selection of included studies may have been biased. Further, our attempt to replicate their results failed; we found that acupoint tapping fared no better than comparison groups:k= 3 studies,d= −0.38 (95% confidence interval, 0.10 to −0.87),p= 0.12. We conclude that the Church et al.'s meta-analysis actually found no specific mental health benefits for acupoint tapping.
Corrigendum to: Is Tapping on Acupuncture Points an Active Ingredient in Emotional Freedom Techniques: A Systematic Review and Meta-Analysis of Comparative Studies
Authors: Church Dawson , Stapleton Peta , Kip Kevin , Gallo Fred
Published: July 2020

We published a meta-analysis of component trials of emotional freedom techniques (EFT) in this journal. EFT is an evidence-based method, validated in over 100 clinical trials, that uses fingertip tapping on acupressure points in conjunction with techniques from exposure and cognitive therapy. The meta-analysis examined six studies in which an active control, such as diaphragmatic breathing or sham acupoints, was used in place of tapping on actual acupoints. The purpose of the meta-analysis was to determine whether tapping was an inert or an active ingredient in EFTs observed treatment effects. Subsequent to publication, errors in the statistical analysis were identified, primarily incorrect standard deviation values, and our methodological approach was questioned by others. We therefore had the meta-analysis rerun by an independent senior statistician who compared pre- to follow-up results to determine the sustained effects of treatment. The cumulative fixed effects Hedge’s g-value was found to be 0.73 (95% confidence interval = 0.42–1.04, p < 0.0001). The corresponding random effects Hedge’s g-value is 0.74 (95% confidence interval = 0.34–1.13, p < 0.0001). We also reviewed and clarified our methodology. In conclusion, despite computational errors in our original publication, the present revised analysis supports the original conclusion that the acupressure component of the EFT protocol is an active ingredient that contributes to the method’s favorable health effects.
New insights on tidal dynamics and tidal energy harvesting in the Alderney Race
Authors: Sentchev Alexei , Thiébot Jérôme , Bennis Anne-Claire , Piggott Matthew
Published: July 2020

The Introduction presents motivations, significance and some key points of the research activities performed in the Alderney Race.

This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.
Underway velocity measurements in the Alderney Race: towards a three-dimensional representation of tidal motions
Authors: Sentchev Alexei , Nguyen Thinh Duc , Furgerot Lucille , Bailly du Bois Pascal
Published: July 2020

The Alderney Race, located northwest of the Cotentin Peninsula (France), is a site with high tidal-stream energy potential. Circulation through the Alderney Race is complex, with current speed exceeding 3 m s
−1
at neap tide. Towed acoustic Doppler current profiler (ADCP) measurements and static point velocity measurements were performed in July 2018 focusing on assessment of circulation and vertical structure of tidal currents. Transect surveys revealed peculiar features of local dynamics such as change in location of the tidal jet on ebb and flood flow. The spatial expanse of the tidal jet was quantified and regions with largely sheared or nearly homogeneous velocity distributions were identified on the cross-sections. Velocity profiles acquired along the cross-sections were accurately characterized using a power law. The spatial variability of the power-law exponent
α
was found to be large and correlated with the tidal conditions. The largest variation in profile shape was observed in the northern sector and assumed to be generated by the current interaction with a bathymetric constriction. The velocity profiles were found to vary from highly sheared on flood flow to nearly homogeneous on ebb flow, with corresponding range of power-law exponent
α
variation from 6 to 14. In the southern sector, over a relatively smooth bathymetry, the velocity profile shape was accurately approximated using the 1/7 power law with a range of variation of
α
from 6.5 to 8, with respect to the tidal conditions. To our knowledge, this is the largest field survey done using towed ADCP and the results could represent a significant advance in tidal site characterization and provide advanced information to turbine developers.

This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race'.
The Alderney Race: general hydrodynamic and particular features
Authors: Bailly du Bois Pascal , Dumas Franck , Morillon Mehdi , Furgerot Lucille , Voiseux Claire , Poizot Emmanuel , Méar Yann , Bennis Anne-Claire
Published: July 2020

This study presents an overview of the main hydrodynamic features of the Alderney Race strait based on
in situ
measurements and two-dimensional hydrodynamic model simulations. The strait encompasses a large amplitude of tidal properties (tidal range and tidal wave propagation) and particularly strong currents exceeding 5 m s
−1
with associated counter currents and gyres. Variations in depth, sea bottom roughness, coastal topography and current orientation around the La Hague Cape provide access to a large variety of original hydrodynamic regimes. Some are revealed as locations with a 0.4 m drop in the mean sea level associated with strong average currents. A resonance effect associated with the offshore currents can also be observed close to the coasts. The ‘St Martin whistle’ occurs in a bay whose gyre centre oscillates with a reversal of the measured current every 5–7 min. The Alderney Race represents a particular area of interest for coastal hydrodynamic studies. The available
in situ
measurement datasets are rich with recordings of: sea levels; acoustic Doppler current profiler current profiles; surface radar currents; waves; dye experiments; surface and in-depth dissolved tracer surveys. Combined with hydrodynamic models, the complexity of this area can be further understood and knowledge of the hydrodynamic process and forcing parameters can be refined, which can be applied to other coastal areas.

This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.
Characterization of the vertical evolution of the three-dimensional turbulence for fatigue design of tidal turbines
Authors: Thiébaut Maxime , Filipot Jean-François , Maisondieu Christophe , Damblans Guillaume , Jochum Christian , Kilcher Levi F. , Guillou Sylvain
Published: July 2020

A system of two coupled four-beam acoustic Doppler current profilers was used to collect turbulence measurements over a 36-h period at a highly energetic tidal energy site in Alderney Race. This system enables the evaluation of the six components of the Reynolds stress tensor throughout a large proportion of the water column. The present study provides mean vertical profiles of the velocity, the turbulence intensity and the integral lengthscale along the streamwise, spanwise and vertical direction of the tidal current. Based on our results and considering a tidal-stream energy convertor (TEC) aligned with the current main direction, the main elements of turbulence prone to affect the structure (material fatigue) and to alter power generation would likely be: (i) the streamwise turbulence intensity (
I

x

), (ii) the shear stress,

v
′

w
′

¯

, (iii) the normal stress,

u

′
2

¯

and (iv) the vertical integral lengthscale (
L

z

). The streamwise turbulence intensity, (
I

x

), was found to be higher than that estimated at other tidal energy sites across the world for similar height above bottom. Along the vertical direction, the length (
L

z

) of the large-scale turbulence eddies was found to be equivalent to the rotor diameter of the TEC Sabella D10. It is considered that the turbulence metrics presented in this paper will be valuable for TECs designers, helping them optimize their designs as well as improve loading prediction through the lifetime of the machines.

This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.
Assessing the turbulent kinetic energy budget in an energetic tidal flow from measurements of coupled ADCPs
Authors: Thiébaut Maxime , Filipot Jean-François , Maisondieu Christophe , Damblans Guillaume , Duarte Rui , Droniou Eloi , Guillou Sylvain
Published: July 2020

Two coupled four-beam acoustic Doppler current profilers were used to provide simultaneous and independent measurements of the turbulent kinetic energy (TKE) dissipation rate ε and the TKE production rate

P

over a 36 h long period at a highly energetic tidal energy site in the Alderney Race. The eight-beam arrangement enabled the evaluation of the six components of the Reynolds stress tensor which allows for an improved estimation of the TKE production rate. Depth-time series of ε,

P

and the Reynolds stresses are provided. The comparison between ε and

P

was performed by calculating individual ratios of ε corresponding to

P

. The depth-averaged ratio

ε

/

P

averaged over whole flood and ebb tide were found to be 2.2 and 2.8 respectively, indicating that TKE dissipation exceeds TKE production. It is shown that the term of diffusive transport of TKE is significant. As a result, non-local transport is important to the TKE budget and the common assumption of a local balance, i.e. a balance between production and dissipation, is not valid at the measurement site.

This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.
The energy yield potential of a large tidal stream turbine array in the Alderney Race
Authors: Coles D. S. , Blunden L. S. , Bahaj A. S.
Published: July 2020

This research provides an updated energy yield assessment for a large tidal stream turbine array in the Alderney Race. The original array energy yield estimate was presented in 2004. Enhancements to this original work are made through the use of a validated two-dimensional hydrodynamic model, enabling the resolution of flow modelling to be improved and the impacts of array blockage to be quantified. Results show that a range of turbine designs (i.e. rotor diameter and power capacity) are needed for large-scale development, given the spatial variation in bathymetry and flow across the Alderney Race. Array blockage causes a reduction in flow speeds in the array of up to 2.5 m s
−1
, increased flow speeds around the array of up to 1 m s
−1
and a reduction in the mean volume flux through the Alderney Race of 8%. The annual energy yield estimate of the array is 3.18 TWh, equivalent to the electricity demand of around 1 million homes. The capacity factor of the array is 18%, implying sub-optimal array design. This result demonstrates the need for turbine rated speed to be selected based on the altered flow regime, not the ambient flow. Further enhancement to array performance is explored through increases to rotor diameter and changes to device micro-siting, demonstrating the significant potential for array performance improvement.

This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.
Tidal current power effects on nearby sandbanks: a case study in the Race of Alderney
Authors: Blunden Luke S. , Haynes Stephen G. , Bahaj AbuBakr S.
Published: July 2020

A validated numerical model of tidal flows and sediment transport around the Alderney South Banks was used to investigate the potential effects of large (300 MW) tidal turbine arrays at different locations in Alderney territorial waters. Two methods were used, firstly looking at hydrodynamic changes only and secondly modelling sediment transport over a non-erodible bed. The baseline hydrodynamic model was validated relative to ADCP velocity data collected in the immediate vicinity of the sandbank. Real-world sand transport rates were inferred from sand-wave migrations and agree favourably with sediment transport residuals calculated from model outputs. Outputs from the sediment model reproduced realistic morphological behaviours over the bank. Seventeen different locations were considered; most did not result in significant hydrodynamic changes over the South Banks; however, three array locations were singled out as requiring extra caution if development were to occur. The results provide a case for optimizing the array locations for twin objectives of maximizing array power and minimizing impacts on the sandbanks.

This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.
Suhomyces drosophilae sp. nov., isolated from Drosophila flies feeding on a stinkhorn mushroom
Authors: Jadhav Reshma , Tiwari Snigdha , Avchar Rameshwar , Groenewald Marizeth , Baghela Abhishek
Published: July 2020

The majority of Suhomyces species have been isolated from fungus-feeding insects and particularly from the gut of beetles. In the present study, seven yeast strains were isolated from the gut of Drosophila species feeding on gleba, the spore-bearing inner mass, of a stinkhorn mushroom belonging to the family Phallaceae. Based on phenotypic, biochemical characterization and sequence analysis of the D1/D2 region of the large subunit rRNA gene and the internal transcribed spacer (ITS) region, two of these yeast strains, DGY3 and DGY4, represented a novel species of the genus Suhomyces. The novel species is closely related to an undescribed species of Candida ST-370 (DQ404513) and with Suhomyces canberraensis, wherein, the novel species differs from S. canberraensis by 40 nucleotide substitutions and three gaps (7.7 % sequence variation) in the D1/D2 region and 50 nucleotide substitutions and seven gaps (13.7 % sequence variation) in the ITS region. Several morphological and physiological differences were also observed between S. canberraensis and the strains obtained during this study. These data support the proposal of Suhomyces drosophilae as a novel species, with DGY3T as the holotype and CBS 16329T and MCC 1871T as ex-type strains.
Epidemiological, clinical and genomic insights into the ongoing diphtheria outbreak in Yemen
Authors: Badell Edgar , Alharazi Abdulilah , Criscuolo Alexis ,   The NCPHL diphtheria outbreak working group, Lefrancq Noemie , Bouchez Valerie , Guglielmini Julien , Hennart Melanie , Carmi-Leroy Annick , Zidane Nora , Pascal-Perrigault Marine , Lebreton Manon , Martini Helena , Salje Henrik , Toubiana Julie , Dureab Fekri , Dhabaan Ghulam , Brisse Sylvain
Published: July 2020

Background

An outbreak of diphtheria, declared in Yemen in October 2017, is still ongoing. Methods. Probable cases were recorded through an electronic diseases early warning system. Microbiological culture, genomic sequencing, antimicrobial susceptibility and toxin production testing were performed.

Methods

Probable cases were recorded through an electronic diseases early warning system. Microbiological culture, genomic sequencing, antimicrobial susceptibility and toxin production testing were performed.

Findings

The Yemen diphtheria outbreak developed in three epidemic waves, which affected nearly all governorates (provinces) of Yemen, with 5701 probable cases and 330 deaths (October 2017 - April 2020). The median age of patients was 12 years (range, 0.17-80). Virtually all outbreak isolates (40 of 43 tested ones) produced the diphtheria toxin. We observed low level of antimicrobial resistance to penicillin. We identified six separateCorynebacterium diphtheriaephylogenetic sublineages, three of which are genetically related to isolates from Saudi Arabia and Somalia. The predominant sublineage was resistant to trimethoprim and was associated with unique genomic features, more frequent neck swelling (p=0.002) and a younger age of patients (p=0.06). Its evolutionary rate was estimated at 1.67 × 10−6substitutions per site year-1, placing its most recent common ancestor in 2015, and indicating silent circulation ofC. diphtheriaein Yemen earlier than outbreak declaration.

Interpretation

We disclose clinical, epidemiological and microbiological characteristics of one of the largest contemporary diphtheria outbreaks and demonstrate clinically relevant heterogeneity ofC. diphtheriaeisolates, underlining the need for laboratory capacity and real-time microbiological analyses to inform prevention, treatment and control of diphtheria.

Funding

This work was supported by institutional funding from the National Centre of the Public Health Laboratories (Sanaa, Yemen) and Institut Pasteur (Paris, France) and by the French Government Investissement d ‘Avenir Program.
Effects of non-pharmaceutical interventions on COVID-19: A Tale of Three Models
Authors: Chin Vincent , Ioannidis John P.A. , Tanner Martin A. , Cripps Sally
Published: July 2020

In this paper, we compare the inference regarding the effectiveness of the various non-pharmaceutical interventions (NPIs) for COVID-19 obtained from three SIR models, all developed by the Imperial College COVID-19 Response Team. One model was applied to European countries and published in Nature1 (model 1), concluding that complete lockdown was by far the most effective measure, responsible for 80% of the reduction in Rt, and 3 million deaths were avoided in the examined countries. The Imperial College team applied a different model to the USA states2 (model 2), and in response to our original submission, the Imperial team has proposed in a referee report a third model which is a hybrid of the first two models (model 3). We demonstrate that inference is highly nonrobust to model specification. In particular, inference regarding the relative effectiveness of NPIs changes substantially with the model and decision makers who are unaware of, or ignore, model uncertainty are underestimating the risk attached to any decisions based on that model. Our primary observation is that by applying to European countries the model that the Imperial College team used for the USA states (model 2), complete lockdown has no or little effect, since it was introduced typically at a point when Rt was already very low. Moreover, using several state-of-the-art metrics for Bayesian model comparison, we demonstrate that model 2 (when applied to the European data) is better supported by the data than the model published in Nature1. In particular, serious doubt is cast on the conclusions in Flaxman et al.1, whether we examine the data up to May 5th (as in Flaxman et al.1) or beyond the point when NPIs began to be lifted. Only by objectively considering a wide variety of models in a statistically principled manner, can one begin to address the effectiveness of NPIs such as lockdown. The approach outlined in this paper provides one such path.
Indigenous knowledge of plant uses by the community of Batiaghata, Khulna, Bangladesh
Authors: Ray Tama , Limon Md. Sharif Hasan , Tuhin Md. Sajjad Hossain , Sharmin Arifa
Published: July 2020

Southwestern region of Bangladesh is very rich in floral diversity, and their diversified uses. An extensive survey was conducted to investigate ethnobotanical applications of botanical species by the community of Khulna, Bangladesh. We focused on plants and community relationships, identify the most important species used, determine the relative importance of the species surveyed and calculated the Fidelity level (FI) and Cultural Significance Index (CSI) concerning individual species. In total, we have listed 136 species of 114 genera under 52 families, of which 32% (45 species) were used for folk medicine. Inheritance of traditional knowledge of medicinal plants was the primary source of knowledge acquisition through oral transmission over the generations. However, only 34% of the informants were traditional herbal practitioners. Most of the medicinal uses are primly associated with anti-inflammatory, anti-microbial, antiseptic, expectorant, antidote, fever reduction, and pain relief.
Safety and Efficacy Concerns of Lopinavir/Ritonavir in COVID-19 Affected Patients: A Retrospective Series
Authors: Lepage Marc-Antoine , Rozza Nicholas , Kremer Richard , Grunbaum Ami
Published: July 2020

Context

Originally developed for the treatment of human immunodeficiency virus (HIV), the antiviral combination lopinavir/ritonavir (LPV/r) is being investigated for use against coronavirus disease (COVID-19). We present a case series raising safety and efficacy concerns in COVID-19 affected patients.

Methods

We measured LPV trough concentrations in 12 patients treated at our center and reviewed their clinical charts for side effects known to occur in HIV patients.

Results

Compared to established LPV trough concentrations in HIV treated patients, concentrations in COVID-19 affected patients were 3-fold greater (20.64 +/- 10.14 mcg/mL versus 6.25 mcg/mL). In addition, cholestasis and dyslipidemia toxicity thresholds were exceeded in 12/12 and 11/12 patients respectively. No patients achieved the presumed therapeutic concentration. The side effects noted were mainly gastrointestinal symptoms (5/12, 42%), electrolytes imbalances (4/12, 33%), liver enzyme disturbances (5/12, 42%), and triglyceride elevations (2/12, 17%).

Conclusion

None of our patients reached presumed therapeutic LPV concentrations despite experiencing side effects and exceeding cholestasis and dyslipidemia toxicity thresholds. This raises concerns for the safety and efficacy of LPV/r. Clinicians should consider closely monitoring for side effects and not necessarily attribute them to COVID-19 itself.
New Insights on Excess Deaths and COVID-19
Authors: Wetzler Harry P. , Cobb Herbert W.
Published: July 2020

Background

Weinberger and colleagues estimated that 27,065 of the 122,300 excess deaths in the United States between March 1 and May 30, 2020 did not have a COVID-19 cause of death.

Methods

The Centers for Disease Control and Prevention (CDC) post weekly data on mortality for 13 causes of death from the most prevalent comorbid conditions reported on death certificates where COVID-19 was listed as a cause of death. The 2015-2019 data for weeks 10 through 22 were used to forecast the number of deaths from the 13 causes in the absence of COVID-19 during 2020. The forecast was subtracted from the observed number of deaths for each cause during the period March 1 to May 30, 2020.

Results

The total of the differences for each of the 13 causes of death, 18,489 deaths, accounts for over two-thirds of the 27,065 excess deaths not due to COVID-19.

Conclusion

Combining the 95,235 reported COVID-19 deaths with the 18,489 from the 13 most frequent comorbid conditions reported on death certificates where COVID-19 was a cause suggests that as many as 93% of the excess deaths were due to COVID-19 and implies that COVID-19 deaths were undercounted. Ongoing assessment of excess deaths and causes of death is needed to provide a better understanding of the pandemic’s dynamics.
Predicting critical state after COVID-19 diagnosis: Model development using a large US electronic health record dataset
Authors: Rinderknecht Mike D. , Klopfenstein Yannick
Published: July 2020

As the COVID-19 pandemic is challenging healthcare systems worldwide, early identification of patients with a high risk of complication is crucial. We present a prognostic model predicting critical state within 28 days following COVID-19 diagnosis trained on data from US electronic health records (IBM Explorys), including demographics, comorbidities, symptoms, insurance types, and hospitalization. Out of 15816 COVID-19 patients, 2054 went into critical state or deceased. Random, stratified train-test splits were repeated 100 times and lead to a ROC AUC of 0.872 [0.868, 0.877] and a precision-recall AUC of 0.500 [0.488, 0.509] (median and interquartile range). The model was well-calibrated, showing minor tendency to overforecast probabilities above 0.5. The interpretability analysis confirmed evidence on major risk factors (e.g., older age, higher BMI, male gender, diabetes, and cardiovascular disease) in an efficient way compared to clinical studies, demonstrating the model validity. Such personalized predictions could enable fine-graded risk stratification for optimized care management.
Accuracy and Acceptability of Wearable Motion Tracking Smartwatches for Inpatient Monitoring
Authors: Auepanwiriyakul Chaiyawan , Waibel Sigourney , Songa Joanna , Bentley Paul , A. Faisal A. Aldo
Published: July 2020

Inertial Measurement Units (IMUs) within an everyday consumer smartwatch offer a convenient and low-cost method to monitor the natural behaviour of hospital patients. However, their accuracy at quantifying limb motion, and clinical acceptability, have not yet been demonstrated. To this end we conducted a two-stage study: First, we compared the inertial accuracy of wrist-worn IMUs, both research-grade (Xsens MTw Awinda, and Axivity AX3) and consumer-grade (Apple Watch Series 3 and 5), relative to gold-standard optical motion tracking (OptiTrack). Given the moderate to strong performance of the consumer-grade sensors we then evaluated this sensor and surveyed the experiences and attitudes of hospital patients (N=44) and staff (N=15) following a clinical test in which patients wore smartwatches for 1.5– 24 hours in the second study. Results indicate that for acceleration, Xsens is more accurate than the Apple smartwatches and Axivity AX3 (RMSE 0.17±0.01 g; R2 0.88±0.01; RMSE 0.22±0.01 g; R2 0.64±0.01; RMSE 0.42±0.01 g; R2 0.43±0.01, respectively). However, for angular velocity, the smartwatches are marginally more accurate than Xsens (RMSE 1.28±0.01 rad/s; R2 0.85±0.00; RMSE 1.37±0.01 rad/s; R2 0.82± SE 0.01, respectively). Surveys indicated that in-patients and healthcare professionals strongly agreed that wearable motion sensors are easy to use, comfortable, unobtrusive, suitable for long term use, and do not cause anxiety or limit daily activities. Our results suggest that smartwatches achieved moderate to strong levels of accuracy compared to a gold-standard reference and are likely to be accepted as a pervasive measure of motion/behaviour within hospitals.
Hospital initiation of benzodiazepines and Z-drugs in older adults and discontinuation in primary care
Authors: Coll Seán , Walsh Mary E , Fahey Tom , Moriarty Frank
Published: July 2020

Objective

To examine factors associated with continuation of hospital-initiated benzodiazepine receptor agonists (BZRAs) among adults aged ≥65 years, specifically instructions on hospital discharge summaries.

Methods

This retrospective cohort study involved anonymised electronic record data on prescribing and hospitalisations for 38,229 patients aged ≥65 from forty-four GP practices in Ireland 2011-2016. BZRA initiations were identified among patients with no BZRA prescription in the previous 12 months. Multivariate regression examined whether instructions on discharge messages for hospital-initiated BZRA prescriptions was associated with continuation after discharge in primary care and time to discontinuation.

Results

Most BZRA initiations occurred in primary care, however the rate of hospital-initiated BZRAs was higher. Almost 60% of 418 hospital initiations had some BZRA instructions (e.g. duration) on the discharge summary. Approximately 40% (n=166) were continued in primary care. Lower age, being prescribed a Z-drug or great number of medicines were associated with higher risk of continuation. Of those continued in primary care, in 98 cases (59.6%) the BZRA was discontinued during follow-up (after a mean 184 days). Presence of instructions was associated with higher likelihood of discontinuation (hazard ratio 1.67, 95%CI 1.09-2.55).

Conclusions

Improved communication to GPs after hospital discharge may be important in avoiding long-term BZRA use.