bluuebunny/crossref_metadata_2025 huggingface dataset:
Using single-electron box arrays for voltage sensing applications
Authors: Filmer Matthew J. , Zirkle Thomas A. , Chisum Jonathan , Orlov Alexei O. , Snider Gregory L.
Published: May 2020

Single-electron tunneling transistors (SETs) and boxes (SEBs) belong to the family of charge-sensitive electronic devices based on the phenomenon of Coulomb blockade. An SEB is a two-terminal device composed of “leaky,” Cj, and “non-leaky,” Cg, nanoscaled capacitors in series. At low temperatures, the charge at the common node is quantized and can only be changed near energy-population degeneracy points, resulting in periodic oscillations of the SEB admittance as a function of voltage applied to Cg. In comparison to the SETs, SEBs have higher operating temperature, are electrostatic discharge tolerant, and have a much smaller footprint. To monitor the SEB admittance, Radio Frequency reflectometry can be used. To improve the signal-to-noise ratio, limited by the small change in admittance in an SEB, multiple devices sharing the same source and gate electrodes are connected in parallel to form arrays of SEBs. Due to unavoidable random offset charges, the signal boost for an array of N SEBs is expected to be ∼N. We experimentally demonstrate that by carefully choosing the operating point, the response to the voltage on the sensing gate can be enhanced, for small arrays scales, by a factor approaching N and, thus, provides a method by which these devices can be used in practical sensing applications, such as a scanning probe.
Atomic scale investigation of the volume phase transition in concentrated PNIPAM microgels
Authors: Zanatta M. , Tavagnacco L. , Buratti E. , Chiessi E. , Natali F. , Bertoldo M. , Orecchini A. , Zaccarelli E.
Published: May 2020

Combining elastic incoherent neutron scattering and differential scanning calorimetry, we investigate the occurrence of the volume phase transition (VPT) in very concentrated poly-(N-isopropyl-acrylamide) (PNIPAM) microgel suspensions, from a polymer weight fraction of 30 wt. % up to dry conditions. Although samples are arrested at the macroscopic scale, atomic degrees of freedom are equilibrated and can be probed in a reproducible way. A clear signature of the VPT is present as a sharp drop in the mean square displacement of PNIPAM hydrogen atoms obtained by neutron scattering. As a function of concentration, the VPT gets smoother as dry conditions are approached, whereas the VPT temperature shows a minimum at about 43 wt. %. This behavior is qualitatively confirmed by calorimetry measurements. Molecular dynamics simulations are employed to complement experimental results and gain further insights into the nature of the VPT, confirming that it involves the formation of an attractive gel state between the microgels. Overall, these results provide evidence that the VPT in PNIPAM-based systems can be detected at different time- and length-scales as well as under overcrowded conditions.
Nonlinear conductivity and breakdown strength characteristics of silicon carbide and hexagonal boron nitride co-doped epoxy resin composites
Authors: Chi Qingguo , Cui Shuang , Zhang Tiandong , Yang Meng , Zhang Yongquan , Zhang Changhai , Lei Qingquan
Published: May 2020

In this study, the method of co-doping semi-conductor silicon carbide (SiC) and insulating inorganic phase hexagonal boron nitride (h-BN) in epoxy resin (EP) composites has been proposed for considering both the nonlinear conductivity and the breakdown strength. First, the epoxy-based composites were fabricated and prepared by hot press vulcanization. Then, the phase structure and the microstructure of the composites were characterized by XRD and SEM. Finally, the nonlinear conductivity and the breakdown strength of the composites were tested. The results indicate that the breakdown strength of the 1 wt. % h-BN/3 wt. % SiC/EP composite reaches 115.6 kV/mm, which is 4 times higher than that of the single-doped 3 wt. % SiC/EP composite. More importantly, the appropriate h-BN and SiC contents of the co-doped EP composites still exhibit excellent nonlinear electrical conductive properties. The results indicate that both the nonlinear conductivity and the breakdown strength have been obtained by the semi-conductor and insulator co-doping strategy.
Genetic parameters for weights from birth to 10 years of age in different beef cow breeds
Authors: Varchaki Portes Juliana , dos Santos Gonçalves Cyrillo Joslaine Noely , El Faro Lenira , Figueiredo Martins Bonilha Sarah , Branco Arnandes Renata Helena , de Almeida Teixeira Rodrigo , Zerlotti Mercadante Maria Eugênia , Talarico Dias Laila
Published: May 2020

Context
Most Brazilian beef breeding programs perform selection for young bodyweight, which will inevitably increase mature weight due to the genetic correlation among weights at different ages.

Aims
The objective of the present study was to estimate genetic parameters for bodyweight from birth to maturity in Gir, Guzerat, Nelore and Caracu cows born between 1981 and 2014 at Centro APTA Bovinos de Corte, Instituto de Zootecnia, Sertãozinho, São Paulo, Brazil.

Methods
The model included the fixed effects of contemporary group (herd and year of birth), month of birth and previous reproductive status (calved = 1, or not calved = 0), the linear and quadratic effects of animal and cow age as covariates, and direct additive genetic, maternal genetic and maternal permanent environmental effects as random effects. The genetic parameters were estimated by univariate analysis of weights adjusted at birth, and at 120, 210, 378, 450 and 550 days of age, and annually from 2 to 10 years. In addition, multivariate analysis was performed considering weights at birth, and at 210 and 550 days, and at 5 years of age for all breeds.

Key results
For the different breeds, the heritability estimates ranged from 0.28 to 0.49 for birthweight, from 0.11 to 0.31 for weaning weight, from 0.25 to 0.43 for yearling weight, and from 0.25 to 0.69 for weights from 2 to 10 years of age. The genetic correlations were high and positive, indicating that selection at any age will affect weights at the other ages.

Conclusions
The results suggest the possibility of genetic progress for weights at different ages and the use of the young weights to monitor the mature weight of the animals.

Implications
As the trait most strongly correlated with mature weight was yearling weight, already used as the selection criteria for females in the breeding program of the Instituto de Zootecnia, selection indexes should be derived to keep the mature cow weight constant, since heavier cows could be undesirable for pasture-based Brazilian production systems.
Spatio-temporal variability of amphipod assemblages associated with rhodolith seabeds
Authors: Navarro-Mayoral Sandra , Fernandez-Gonzalez Victoria , Otero-Ferrer Francisco , Tuya Fernando
Published: May 2020

Rhodolith seabeds are habitats underpinned by free-living calcareous macroalgae. We partitioned the relevance of the scale of temporal (four seasons throughout two successive years) and spatial (three depth strata: 18, 25 and 40m) variation on the diversity, structure and abundance of amphipod assemblages living in rhodolith seabeds from Gran Canaria Island. In total, 3996 individuals, belonging to 32 taxa, were identified. Multivariate analyses showed consistent differences in assemblage structure among seasons and depths; more diverse and abundant amphipod assemblages were often observed during spring at 18- and 25-m than at 40-m depth. Ovigerous females of Gammaropsis ostroumowi and Ampithoe ramondi were observed mainly at 18 and 25m. Juveniles of both species were exclusively recorded at 18 and 25m, so denoting a clear segregation in their population structure with depth. In summary, this study has demonstrated that the ecological pattern of amphipods associated with rhodolith seabeds can vary greatly across both time (seasons) and space (depth).
The predominantly fresh history of Lake Alexandrina, South Australia, and its implications for the Murray–Darling Basin Plan: a comment on Gell (2020)
Authors: Tibby John , Haynes Deborah , Muller Kerri
Published: May 2020

The pre-European settlement state of Lake Alexandrina, a lake system at the mouth of the River Murray has been the subject of some debate. Fluin et al. (2007) concluded on the basis of diatom evidence from sediment cores that ‘Marine water indicators were never dominant in Lake Alexandrina’. In a report to the South Australian Government, Fluin et al. (2009) stated, consistent with the earlier research, that ‘There is no evidence in the 7000 year record of substantial marine incursions into Lake Alexandrina’. Gell (2020) has argued both that Fluin et al. (2009) is in error and claims that it, and Sim and Muller’s (2004) book that describes early European settler accounts of the lake being fresh, underpin water provisions for Lake Alexandrina under the Murray–Darling Basin Plan. This response demonstrates that all these claims are untrue. Of the three diatom species suggested by Gell (2020) to be indicators of marine waters, Thalassiosira lacustris grows in the freshwater River Murray today, Cyclotella striata was never more than a minor component of the diatom flora and Paralia sulcata has not been detected in the lake in over 3000 years. Water provisions for Lake Alexandrina under The Basin Plan are founded on contemporary environmental water requirements and achievement of agreed socio-ecological-economic objectives, rather than the history of the lake. Nevertheless, the aim to maintain the lake as a freshwater ecosystem under The Murray–Darling Basin Plan is consistent with its history.
Migratory behavior and winter geography drive differential range shifts of eastern birds in response to recent climate change
Authors: Rushing Clark S. , Royle J. Andrew , Ziolkowski David J. , Pardieck Keith L.
Published: May 2020

Significance

Over the past half century, populations of neotropical migratory birds in North America have plummeted while populations of resident species have largely remained stable. We show that resident and migratory birds in eastern North America have responded differently to climate change over this period, with the ranges of resident species expanding along their northern margin while the ranges of migratory species have contracted at their southern margin. These results suggest that the ability to colonize newly suitable areas may make resident species resilient to future climate change but that climate-induced range contractions may make neotropical migrants vulnerable to these changes.
Molecular electronic decoherence following attosecond photoionisation
Authors: Arnold Caroline , Larivière-Loiselle Céline , Khalili Khadijeh , Inhester Ludger , Welsch Ralph , Santra Robin
Published: May 2020

Attosecond pulses can be used to generate coherent superpositions of cationic electronic states in molecules through photoionisation. These can drive coherent electronic dynamics, which may decay within a few femtoseconds due to nuclear motion. In this work, we study the impact of the photoelectron on decoherence in the valence electron system of molecules following attosecond photoionisation. To this end, we include the photoelectron as a classical point charge in a quantum–classical simulation of light-induced ultrafast molecular dynamics and consider ionisation by sub-femtosecond pulses with distinct qualities. By disentangling the contributions of photoelectron and nuclei to the overall electronic decoherence, we find that the photoelectron causes partial decoherence within the first 50 attoseconds. This timescale is noticed to be independent of the ionising pulse. Full electronic decoherence is only seen when the spatial extension of the nuclear wave packet is considered.
Variational-state quantum metrology
Authors: Koczor Bálint , Endo Suguru , Jones Tyson , Matsuzaki Yuichiro , Benjamin Simon C
Published: May 2020

Quantum technologies exploit entanglement to enhance various tasks beyond their classical limits including computation, communication and measurements. Quantum metrology aims to increase the precision of a measured quantity that is estimated in the presence of statistical errors using entangled quantum states. We present a novel approach for finding (near) optimal states for metrology in the presence of noise, using variational techniques as a tool for efficiently searching the high-dimensional space of quantum states, which would be classically intractable. We comprehensively explore systems consisting of up to 9 qubits and find new highly entangled states that are not symmetric under permutations and non-trivially outperform previously known states up to a constant factor 2. We consider a range of environmental noise models; while passive quantum states cannot achieve a fundamentally superior scaling (as established by prior asymptotic results) we do observe a significant absolute quantum advantage. We finally outline a possible experimental setup for variational quantum metrology which can be implemented in near-term hardware.
The effect of astigmatism induced by refraction on the orbital angular momentum of light
Authors: Ritboon Atirach
Published: May 2020

We use the Fourier transform and Snell’s law to demonstrate how refraction at a flat interface induces astigmatism and transforms the spatial distribution of a stigmatic beam. Refraction makes the beam parameters for the transverse dimensions perpendicular and parallel to the plane of incidence grow differently and gives rise astigmatism. The decompositions of the orbital angular momentum of the beam before and after refraction are different. A single-value state of orbital angular momentum of the incident photon in a Laguerre–Gaussian mode is transformed into a superposition state.
Microstructures and properties of in-situ (ZrB2 + Al2O3)np/AA6111 composites synthesized under magnetic and ultrasonic fields
Authors: Xia Chaoyi , Zhao Yutao , Chen Fei , Kai Xizhou , Tao Ran , Fang Zheng , Sun Yue
Published: May 2020

ZrB2 and Al2O3 nanoparticle-reinforced aluminum matrix composites were successfully prepared by in situ chemical reaction of the Al-Na2B4O7-K2ZrF6 system with magnetic field applied in the in situ reaction and ultrasonic field introduced in solidification. The results indicated that the optimized magnetic frequency was 10 Hz, and the ultrasonic power was 1.0 kW. XRD analysis showed that ZrB2 and Al2O3 nanoparticles have been obtained. The smaller clusters were evenly distributed in the matrix. ZrB2 and Al2O3 nanoparticles were dispersed and uniformly distributed. The average size of particles and grain size of (ZrB2 + Al2O3)np/AA6111 composites were refined to 45 ± 10 nm and 50.4 ± 12 μm, respectively. The maximum Vickers hardness, tensile strength, yield strength and elongation of the composites synthesized under the optimized magnetic and ultrasonic fields were 142.2 HV, 355.4 MPa, 259.4 MPa and 22.4%, which were 1.34, 1.36, 1.35 and 1.33 times higher than that of AA6111 alloy, respectively.
Thermal shock resistance of tungsten with various deformation degrees under transient high heat flux
Authors: Zhang Xiaoxin , Gong Zheng , Huang Jianjun , Yu Bin
Published: May 2020

Tungsten (W) is considered as the most promising plasma facing material in fusion device, which will be exposed to steady and transient heat loads. Usually, the deformation degree of W influences its thermal shock properties. So we evaluated the thermal shock resistance of rolled pure tungsten (PW) with 60%, 90% deformation degrees and W-1.0wt%La2O3 (WL10) with 52%, 88% deformation degrees using electron beam at an absorbed power density of 0.22 GW m−2 for 5 ms and further discussed the relationship between the thermal shock resistance and microstructures, thermal-mechanical properties. The absorbed beam current (30 mA), electron beam acceleration voltage (120 kV) and loaded area (4 × 4 mm2) is used to estimate the absorbed power density. The results indicated that PW-90%, LW-88% exhibited smaller grain size, higher relative density, microhardness but lower strength, thermal conductivity compared to PW-60%, LW-52%. The cracking threshold was <0.22 GW m−2 for PW-60%, LW-52% and >0.22 GW m−2 for PW-90%, LW-88%. Elliptic left pores in PW-60% and LW-52% aggravated the effect of stress concentration cracking during the transient high heat flux test and decreased the cracking threshold altough they exhibited high strength and thermal conductivity.
Red flowers differ in shades between pollination systems and across continents
Authors: Chen Zhe , Niu Yang , Liu Chang-Qiu , Sun Hang
Published: May 2020

Background and Aims

Floral colour is a primary signal in plant–pollinator interactions. The association between red flowers and bird pollination is well known, explained by the ‘bee avoidance’ and ‘bird attraction’ hypotheses. Nevertheless, the relative importance of these two hypotheses has rarely been investigated on a large scale, even in terms of colour perception per se.

Methods

We collected reflectance spectra for 130 red flower species from different continents and ascertained their pollination systems. The spectra were analysed using colour vision models for bees and (three types of) birds, to estimate colour perception by these pollinators. The differences in colour conspicuousness (chromatic and achromatic contrast, purity) and in spectral properties between pollination systems and across continents were analysed.

Key Results

Compared with other floral colours, red flowers are very conspicuous to birds and much less conspicuous to bees. The red flowers pollinated by bees and by birds are more conspicuous to their respective pollinators. Compared with the bird flowers in the Old World, the New World ones are less conspicuous to bees and may be more conspicuous not only to violet-sensitive but also to ultraviolet-sensitive birds. These differences can be explained by the different properties of the secondary reflectance peak (SP). SP intensity is higher in red flowers pollinated by bees than those pollinated by birds (especially New World bird flowers). A transition from high SP to low SP in red flowers can induce chromatic contrast changes, with a greater effect on reducing attraction to bees than enhancing attraction to birds.

Conclusions

Shades of red flowers differ between pollination systems. Moreover, red bird flowers are more specialized in the New World than in the Old World. The evolution towards colour specialization is more likely to result in higher efficiency of bee avoidance than bird attraction
Detecting Gene Ontology misannotations using taxon-specific rate ratio comparisons
Authors: Wei Xiaoqiong , Zhang Chengxin , Freddolino Peter L , Zhang Yang
Published: May 2020

Motivation

Many protein function databases are built on automated or semi-automated curations and can contain various annotation errors. The correction of such misannotations is critical to improving the accuracy and reliability of the databases.

Results

We proposed a new approach to detect potentially incorrect Gene Ontology (GO) annotations by comparing the ratio of annotation rates (RAR) for the same GO term across different taxonomic groups, where those with a relatively low RAR usually correspond to incorrect annotations. As an illustration, we applied the approach to 20 commonly studied species in two recent UniProt-GOA releases and identified 250 potential misannotations in the 2018-11-6 release, where only 25% of them were corrected in the 2019-6-3 release. Importantly, 56% of the misannotations are ‘Inferred from Biological aspect of Ancestor (IBA)’ which is in contradiction with previous observations that attributed misannotations mainly to ‘Inferred from Sequence or structural Similarity (ISS)’, probably reflecting an error source shift due to the new developments of function annotation databases. The results demonstrated a simple but efficient misannotation detection approach that is useful for large-scale comparative protein function studies.

Availability and implementation

https://zhanglab.ccmb.med.umich.edu/RAR.

Supplementary information

Supplementary data are available at Bioinformatics online.
Role of AMP-activated protein kinase during postovulatory aging of mouse oocytes†
Authors: Sun Guang-Yi , Gong Shuai , Kong Qiao-Qiao , Li Zhi-Bin , Wang Jia , Xu Ming-Tao , Luo Ming-Jiu , Tan Jing-He
Published: May 2020

Studies suggested that postovulatory oocyte aging might be prevented by maintaining a high maturation-promoting factor (MPF) activity. Whether AMP-activated protein kinase (AMPK) plays any role in postovulatory oocyte aging is unknown. Furthermore, while activation of AMPK stimulates meiotic resumption in mouse oocytes, it inhibits meiotic resumption in pig and bovine oocytes. Thus, the species difference in AMPK regulation of oocyte MPF activities is worth in-depth studies. This study showed that AMPK activation with metformin or 5-aminoimidazole- 4-carboxamide- 1-beta-d- ribofuranoside and inactivation with compound C significantly increased and decreased, respectively, the activation susceptibility (AS) and other aging parameters in aging mouse oocytes. While AMPK activity increased, MPF activity and cyclic adenosine monophosphate (cAMP) decreased significantly with time post ovulation. In vitro activation and inactivation of AMPK significantly decreased and increased the MPF activity, respectively. MPF upregulation with MG132 or downregulation with roscovitine completely abolished the effects of AMPK activation or inactivation on AS of aging oocytes, respectively. AMPK facilitated oocyte aging with increased reactive oxygen species (ROS) and cytoplasmic calcium. Furthermore, treatment with Ca2+/calmodulin-dependent protein kinase (CaMK) inhibitors significantly decreased AS and AMPK activation. Taken together, the results suggested that AMPK facilitated oocyte aging through inhibiting MPF activities, and postovulatory oocyte aging activated AMPK with decreased cAMP by activating CaMKs via increasing ROS and cytoplasmic calcium.
Environmental Factors Shape Sleep EEG Connectivity During Early Adolescence
Authors: Markovic Andjela , Kaess Michael , Tarokh Leila
Published: May 2020

Quantifying the degree to which genetic and environmental factors shape brain network connectivity is critical to furthering our understanding of the developing human brain. Sleep, a state of sensory disengagement, provides a unique opportunity to study brain network activity noninvasively by means of sleep electroencephalography (EEG) coherence. We conducted a high-density sleep EEG study in monozygotic (MZ; n = 38; mean age = 12.46; 20 females) and dizygotic (DZ; n = 24; mean age = 12.50; 12 females) twins to assess the heritability of sleep EEG coherence in early adolescence—a period of significant brain rewiring. Structural equation modeling was used to estimate three latent factors: genes, environmental factors shared between twins and environmental factors unique to each twin. We found a strong contribution of unique environmental factors (66% of the variance) and moderate genetic influence (19% of the variance) on sleep EEG coherence across frequencies and sleep states. An exception to this was sleep spindle activity, an index of the thalamocortical network, which showed on average a genetic contribution of 48% across connections. Furthermore, we observed high intraindividual stability of coherence across two consecutive nights suggesting that despite only a modest genetic contribution, sleep EEG coherence is like a trait. Our findings in adolescent humans are in line with earlier findings in animals that show the primordial cerebral map and its connections are plastic and it is through interaction with the environment that the pattern of brain network connectivity is shaped. Therefore, even in twins living together, small differences in the environment may cascade into meaningful differences in brain connectivity.
Lower Rate of Seropositivity to Measles Among Young Healthcare Personnel in New York City
Authors: Lucca Anabella , Bayoumi Nagla , Ramanathan Lakshmi V , Sepkowitz Kent , Kamboj Mini
Published: May 2020

We examined the prevalence of measles antibody among 12 349 newly hired HCP between 2009 and 2019. Younger HCP were significantly more likely to have no immunity. Compared with a 92.2% seropositive rate among 1057 persons hired at age >50 years, only 84.4% of approximately 10 000 HCP aged <40 years had protective antibody.
Gut Microbiota Features on Nursing Home Admission Are Associated With Subsequent Acquisition of Antibiotic-resistant Organism Colonization
Authors: Wang Joyce , Cassone Marco , Gibson Kristen , Lansing Bonnie , Mody Lona , Snitkin Evan S , Rao Krishna
Published: May 2020

Nursing home (NH) patients often acquire colonization with antibiotic-resistant organisms (AROs). We show that patients exposed to broad-spectrum antibiotics during previous hospitalizations have elevated enterococcal relative abundances on NH admission and higher risk of subsequent ARO acquisition. Our findings suggest that interventions preventing ARO spread should extend beyond NH doors.
Within-Season Producer Response to Warmer Temperatures: Defensive Investments by Kenyan Farmers
Authors: Jagnani Maulik , Barrett Christopher B , Liu Yanyan , You Liangzhi
Published: May 2020

We present evidence that farmers adjust agricultural inputs in response to within-season temperature variation, undertaking defensive investments to reduce the adverse agro-ecological impacts of warmer temperatures. Using panel data from Kenyan maize-growing households, we find that higher temperatures early in the growing season increase the use of pesticides, while reducing fertiliser use. Warmer temperatures throughout the season increase weeding effort. These adjustments arise because greater heat increases the incidence of pests, crop diseases and weeds, compelling farmers to divert investment from productivity-enhancing technologies such as fertiliser to adaptive, loss-reducing, defensive inputs such as pesticides and weeding labour.
Reproductive system infections in women: upper genital tract, fetal, neonatal and infant syndromes
Authors: Brunham Robert C , Paavonen Jorma
Published: May 2020

Lower genital tract infection and bloodborne spread of infection are the two principal modes for infection of the upper genital tract or for infection of the fetus, neonate or infant. Treponema pallidum and human immunodeficiency virus (HIV) are the two most common bloodborne pathogens that infect the fetus, neonate or infant. Most infections of the upper genital tract, however, spread along epithelial surfaces from the vagina or cervix to the upper genital tract or chorioamnion, fetus, neonate or infant. These infections are caused by either pathogens associated with a dysbiotic vaginal microbiome or those that are sexually transmitted. The clinical syndromes that these pathogens produce in the lower genital tract were discussed in part one of this review. We now discuss the syndromes and pathogens that affect the upper genital tract of both non-pregnant and pregnant women as well as fetus, neonate and infant.
Uneven Missing Data Skew Phylogenomic Relationships within the Lories and Lorikeets
Authors: Smith Brian Tilston , Mauck William M , Benz Brett W , Andersen Michael J
Published: May 2020

The resolution of the Tree of Life has accelerated with advances in DNA sequencing technology. To achieve dense taxon sampling, it is often necessary to obtain DNA from historical museum specimens to supplement modern genetic samples. However, DNA from historical material is generally degraded, which presents various challenges. In this study, we evaluated how the coverage at variant sites and missing data among historical and modern samples impacts phylogenomic inference. We explored these patterns in the brush-tongued parrots (lories and lorikeets) of Australasia by sampling ultraconserved elements in 105 taxa. Trees estimated with low coverage characters had several clades where relationships appeared to be influenced by whether the sample came from historical or modern specimens, which were not observed when more stringent filtering was applied. To assess if the topologies were affected by missing data, we performed an outlier analysis of sites and loci, and a data reduction approach where we excluded sites based on data completeness. Depending on the outlier test, 0.15% of total sites or 38% of loci were driving the topological differences among trees, and at these sites, historical samples had 10.9× more missing data than modern ones. In contrast, 70% data completeness was necessary to avoid spurious relationships. Predictive modeling found that outlier analysis scores were correlated with parsimony informative sites in the clades whose topologies changed the most by filtering. After accounting for biased loci and understanding the stability of relationships, we inferred a more robust phylogenetic hypothesis for lories and lorikeets.
Prediction of Balance Perturbations and Falls on Stairs in Older People Using a Biomechanical Profiling Approach: A 12-Month Longitudinal Study
Authors: Ackermans Thijs , Francksen Natasha , Lees Carolyn , Papatzika Fyllis , Arampatzis Adamantios , Baltzopoulos Vasilios , Lisboa Paulo , Hollands Mark , O’Brien Thomas , Maganaris Constantinos
Published: May 2020

Background

Stair falls are a major health problem for older people, but presently, there are no specific screening tools for stair fall prediction. The purpose of the present study was to investigate whether stair fallers could be differentiated from nonfallers by biomechanical risk factors or physical/psychological parameters and to establish the biomechanical stepping profile posing the greatest risk for a stair fall.

Methods

Eighty-seven older adults (age: 72.1 ± 5.2 years) negotiated an instrumented seven-step staircase and performed a range of physical/psychological tasks. k-Means clustering was used to profile the overall stair negotiation behavior with biomechanical parameters indicative of fall risk as input. Falls and events of balance perturbation (combined “hazardous events”) were then monitored during a 12-month follow-up. Cox-regression analysis was performed to examine whether physical/psychological parameters or biomechanical outcome measures could predict future hazardous events. Kaplan–Meier survival curves were obtained to identify the stepping strategy posing a risk for a hazardous event.

Results

Physical/psychological parameters did not predict hazardous events and the commonly used Fall Risk Assessment Tool classified only 1/17 stair fallers at risk for a fall. Single biomechanical risk factors could not predict hazardous events on stairs either. On the contrary, two particular clusters identified by the stepping profiling method in stair ascent were linked with hazardous events.

Conclusion

This highlights the potential of the stepping profiling method to predict stair fall risk in older adults against the limited predictability of single-parameter approaches currently used as screening tools.
The challenges of detecting and attributing ocean acidification impacts on marine ecosystems
Authors: Doo Steve S , Kealoha Andrea , Andersson Andreas , Cohen Anne L , Hicks Tacey L , Johnson Zackary I , Long Matthew H , McElhany Paul , Mollica Nathaniel , Shamberger Kathryn E F , Silbiger Nyssa J , Takeshita Yuichiro , Busch D Shallin
Published: May 2020

A substantial body of research now exists demonstrating sensitivities of marine organisms to ocean acidification (OA) in laboratory settings. However, corresponding in situ observations of marine species or ecosystem changes that can be unequivocally attributed to anthropogenic OA are limited. Challenges remain in detecting and attributing OA effects in nature, in part because multiple environmental changes are co-occurring with OA, all of which have the potential to influence marine ecosystem responses. Furthermore, the change in ocean pH since the industrial revolution is small relative to the natural variability within many systems, making it difficult to detect, and in some cases, has yet to cross physiological thresholds. The small number of studies that clearly document OA impacts in nature cannot be interpreted as a lack of larger-scale attributable impacts at the present time or in the future but highlights the need for innovative research approaches and analyses. We summarize the general findings in four relatively well-studied marine groups (seagrasses, pteropods, oysters, and coral reefs) and integrate overarching themes to highlight the challenges involved in detecting and attributing the effects of OA in natural environments. We then discuss four potential strategies to better evaluate and attribute OA impacts on species and ecosystems. First, we highlight the need for work quantifying the anthropogenic input of CO2 in coastal and open-ocean waters to understand how this increase in CO2 interacts with other physical and chemical factors to drive organismal conditions. Second, understanding OA-induced changes in population-level demography, potentially increased sensitivities in certain life stages, and how these effects scale to ecosystem-level processes (e.g. community metabolism) will improve our ability to attribute impacts to OA among co-varying parameters. Third, there is a great need to understand the potential modulation of OA impacts through the interplay of ecology and evolution (eco–evo dynamics). Lastly, further research efforts designed to detect, quantify, and project the effects of OA on marine organisms and ecosystems utilizing a comparative approach with long-term data sets will also provide critical information for informing the management of marine ecosystems.
The use of extracorporeal membrane oxygenation in the setting of postinfarction mechanical complications: outcome analysis of the Extracorporeal Life Support Organization Registry
Authors: Matteucci Matteo , Fina Dario , Jiritano Federica , Meani Paolo , Raffa Giuseppe Maria , Kowalewski Mariusz , Aldobayyan Ibrahim , Turkistani Mohammad , Beghi Cesare , Lorusso Roberto
Published: May 2020

OBJECTIVES

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been recently considered and used for patients with post-acute myocardial infarction mechanical complications (post-AMI MC); however, information in this respect is scarce. The purpose of this study was to evaluate the in-hospital outcomes of patients with post-AMI MC submitted to VA-ECMO, and enrolled in the Extracorporeal Life Support Organizations (ELSO)’s data Registry.

METHODS

This was a retrospective review of the ELSO Registry to identify adult (>18 years old) patients with post-AMI MC who underwent VA-ECMO support between 2007 and 2018. The primary end point of this study was in-hospital survival. ECMO complications were also evaluated.

RESULTS

The patient cohort available for this study included 158 patients. The median age was 62.4 years (range 20–80). The most common post-AMI MC was ventricular septal rupture (n = 102; 64.5%), followed by papillary muscle rupture (n = 42; 26.6%) and ventricular free-wall rupture (n = 14; 8.9%). Approximately a quarter of patients (n = 41; 25.9%) had cardiac arrest before VA-ECMO institution. The median duration of VA-ECMO was 5.9 days (range 1 h–40.3 days). ECMO complications occurred in 119 patients (75.3%). Overall, survival to hospital discharge for the entire patient cohort was 37.3%. Patients who had ventricular septal rupture as primary diagnosis had higher in-hospital mortality (n = 66; 64.7%).

CONCLUSIONS

In patients with post-AMI MC, VA-ECMO provides haemodynamic stabilizations and carries a potential to reverse otherwise lethal course. ECMO complications, however, remain an important limitation. Further investigations are required to better evaluate the efficacy and safety of ECMO in this context.
A 0.6-protamine/heparin ratio in cardiac surgery is associated with decreased transfusion of blood products
Authors: Goedhart Anne L M , Gerritse Bastiaan M , Rettig Thijs C D , van Geldorp Martijn W A , Bramer Sander , van der Meer Nardo J M , Boonman-de Winter Leandra J , Scohy Thierry V
Published: May 2020

OBJECTIVES

In cardiac surgery, adequate heparinization is necessary to prevent thrombus formation in the cardiopulmonary bypass (CPB). To counteract the heparin effect after weaning from CPB, protamine is administered. The optimal protamine/heparin ratio is still unknown.

METHODS

In this before–after study, we evaluated the effect of a 0.6/1-protamine/heparin ratio implementation as of May 2017 versus a 0.8/1-protamine/heparin ratio on the 12-h postoperative blood loss and the amount of blood and blood component transfusions (fresh frozen plasma, packed red blood cells, fibrinogen concentrate, platelet concentrate and prothrombin complex concentrate) after cardiac surgery. A total of 2051 patients who underwent cardiac surgery requiring CPB between May 2016 and May 2018 were included.

RESULTS

In the 0.6/1-protamine/heparin ratio group, only 28.8% of the patients received blood component transfusion, compared to 37.9% of the patients in the 0.8/1-ratio group (P < 0.001). The median 12-h postoperative blood loss was 230 ml (interquartile range 140–320) in the 0.6/1-ratio group versus 260 ml (interquartile range 155–365) in the 0.8/1-ratio group (P < 0.001).

CONCLUSIONS

A 0.6/1-protamine/heparin ratio after weaning from CPB is associated with a significantly reduced 12-h postoperative blood loss and blood components transfusion.
Mapping of HIV-1C Transmission Networks Reveals Extensive Spread of Viral Lineages Across Villages in Botswana Treatment-as-Prevention Trial
Authors: Novitsky Vlad , Zahralban-Steele Melissa , Moyo Sikhulile , Nkhisang Tapiwa , Maruapula Dorcas , McLane Mary Fran , Leidner Jean , Bennett Kara ,   PANGEA Consortium, Abeler-Dörner Lucie , Bonsall David , Fraser Christophe , Golubchik Tanya , Ayles Helen , Bowden Rory , Calvez Vincent , Fidler Sarah , Grabowski Kate , Kagaayi Joseph , Hayes Richard , Seeley Janet , Herbeck Joshua , Lingappa Jairam , Kaleebu Pontiano , Ssemwanga Deogratius , Pillay Deenan , Tanser Frank , Quinn Thomas , Rambaut Andrew , Leigh-Brown Andrew , Ratmann Oliver , Wawer Maria , Cohen Myron , Dennis Ann , D’Oliveira Tulio , Frampton Dan , Hoppe Anne , Kellam Paul , Kityo Cissy , Paton Nick , Wirth Kathleen E , Gaolathe Tendani , Kadima Etienne , Chakalisa Unoda , Pretorius Holme Molly , Lockman Shahin , Mmalane Mompati , Makhema Joseph , Gaseitsiwe Simani , DeGruttola Victor , Essex M
Published: May 2020

Background

Phylogenetic mapping of HIV-1 lineages circulating across defined geographical locations is promising for better understanding HIV transmission networks to design optimal prevention interventions.

Methods

We obtained near full-length HIV-1 genome sequences from people living with HIV (PLWH), including participants on antiretroviral treatment in the Botswana Combination Prevention Project, conducted in 30 Botswana communities in 2013–2018. Phylogenetic relationships among viral sequences were estimated by maximum likelihood.

Results

We obtained 6078 near full-length HIV-1C genome sequences from 6075 PLWH. We identified 984 phylogenetically distinct HIV-1 lineages (molecular HIV clusters) circulating in Botswana by mid-2018, with 2–27 members per cluster. Of these, dyads accounted for 62%, approximately 32% (n = 316) were found in single communities, and 68% (n = 668) were spread across multiple communities. Men in clusters were approximately 3 years older than women (median age 42 years, vs 39 years; P < .0001). In 65% of clusters, men were older than women, while in 35% of clusters women were older than men. The majority of identified viral lineages were spread across multiple communities.

Conclusions

A large number of circulating phylogenetically distinct HIV-1C lineages (molecular HIV clusters) suggests highly diversified HIV transmission networks across Botswana communities by 2018.
Prolonged empirical antibiotic therapy is correlated with bloodstream infections and increased mortality in a tertiary care hospital in Ethiopia: bacteriology testing matters
Authors: Semret Makeda , Abebe Workeabeba , Kong Ling Yuan , Alemayehu Tinsae , Beyene Temesgen , Libman Michael D , Amogne Wondwossen , Johannsen Øystein Haarklau , Gebretekle Gebremedhin B , Seifu Daniel , Yansouni Cedric P
Published: May 2020

Background

Hospital-associated infection (HAI) and antimicrobial resistance (AMR) are major health threats in low- and middle-income countries (LMICs). Because diagnostic capacity is lacking throughout most of Africa, patients are commonly managed with prolonged empirical antibiotic therapy. Our goal was to assess mortality in relation to HAI and empirical therapy in Ethiopia’s largest referral hospital.

Methods

Cohort study of patients with suspected HAI at Tikur Anbessa Specialized Hospital from October 2016 to October 2018. Blood culture testing was performed on an automated platform. Primary outcomes were proportion of patients with bloodstream infection (BSI), antibiotic resistance patterns and 14 day mortality. We also assessed days of therapy (DOT) pre- and post-blood culture testing.

Results

Of 978 enrolled patients, 777 had blood culture testing; 237 (30%) had a BSI. Enterobacteriaceae were isolated in 49%; 81% of these were cephalosporin resistant and 23% were also carbapenem resistant. Mortality at 14 days was 31% and 21% in those with and without BSI, respectively. Ceftriaxone resistance was strongly correlated with mortality. Patients with BSI had longer DOT pre-blood culture testing compared with those without BSI (median DOT 12 versus 3 days, respectively, P < 0.0001). After testing, DOT were comparable between the two groups (20 versus 18 days, respectively).

Conclusions

BSI are frequent and fatal among patients with suspected HAI in Ethiopia. Highly resistant blood isolates are alarmingly common. This study provides evidence that investing in systematic blood culture testing in LMICs identifies patients at highest risk of death and that empirical management is frequently inappropriate. Major investments in laboratory development are critical to achieve better outcomes.
C-terminal aromatic residue of Plasmodium ferredoxin important for the interaction with ferredoxin: NADP(H) oxidoreductase: possible involvement for artemisinin resistance of human malaria parasites
Authors: Kimata-Ariga Yoko , Sakamoto Asako , Kamatani Miho , Saitoh Takashi , Hase Toshiharu
Published: May 2020

The malaria parasite (Plasmodium sp.) contains a plastid-derived organelle called the apicoplast, which is essential for the growth of the parasite. In this organelle, a redox system comprising plant-type ferredoxin (Fd) and Fd: NADP(H) oxidoreductase (FNR) supplies reducing power for the crucial metabolic pathways. Electron transfer between Plasmodium falciparum Fd (PfFd) and FNR (PfFNR) is performed with higher affinity and specificity than those of plant Fd and FNR. We investigated the structural basis for such superior protein–protein interaction by focussing on the Plasumodium-specific regions of PfFd. Significant contribution of the C-terminal region of PfFd for the electron transfer with PfFNR was revealed by exchanging the C-terminal three residues between plant Fd and PfFd. Further site-directed mutagenesis of the PfFd C-terminal residues indicated that the presence of aromatic residue at Positions 96 and 97 contributes to the lower Km for PfFNR. Physical binding analyses using fluorescence and calorimetric measurements supported the results. A mutation from Asp to Tyr at position 97 of PfFd was recently reported to be strongly associated with P. falciparum resistance to artemisinin, the front line anti-malarial drug. Thus, the enhanced interaction of PfFd D97Y protein with PfFNR could be involved in artemisinin resistance of human malaria parasites.
Health Information, Treatment, and Worker Productivity
Authors: Dillon Andrew , Friedman Jed , Serneels Pieter
Published: May 2020

Agricultural and other physically demanding sectors are important sources of growth in developing countries, but prevalent diseases such as malaria can adversely impact the productivity and labor supply of workers. We estimate the impact of malaria infection on worker earnings, labor supply, daily productivity, and task selection by using a phased-in design where we randomize the study week in which piece-rate workers at a large sugarcane plantation in Nigeria are offered malaria testing and treatment. Two estimation strategies indicate a significant and substantial intent to treat effect of the intervention. The program increases worker weekly earnings by 11%–13% over the weeks following the offer, depending on the reference period, estimated using a between-worker estimator that exploits the experimental design. A within-worker estimate provides similar but smaller estimates of 8%–10%. We identify different pathways through which this effect occurs. For workers who test positive for malaria, the treatment of illness principally increases labor supply, leading to higher earnings. For workers who test negative, the health information leads to increased earnings via augmented daily productivity. This productivity response arises, in part, from selection into higher return tasks within their job at the plantation. The results underline the importance of medical treatment but also of improved access to information about one's health status, as the absence of either leads workers to work less or choose lower return tasks when working.
A Sustainable Psychosocial Model to Support the National Investigation and Prosecution of Conflict-related Sexual Violence Crimes
Authors: Bianchini Barbara , Rubert Sara
Published: May 2020

This article presents a psychosocial model that can be used by national jurisdictions to cope with the multiple challenges in prosecuting conflict-related sexual violence crimes. Best practices developed over years of professional experience with victims of crime and trauma survivors guided the authors in developing a trauma-centred approach. In the proposed model, the judiciary plays a central role in empowering survivors of heinous crimes to become active agents of their lives by positively contributing to the quest for justice. The authors aim at offering specific and practical recommendations to investigative and judicial staff dealing with the multifaceted issues arising out of conflict-related sexual violence prosecutions. The hope is to offer a flexible model that can be adapted to different national jurisdictions’ needs, can produce sustainable long-term interventions for survivors’ well-being, and improve the quality of the evidence collected.
Examining Gender Inequality and Armed Conflict at the Subnational Level
Authors: Forsberg Erika , Olsson Louise
Published: May 2020

A growing body of quantitative research points to a robust relationship between gender inequality and armed conflict. In order to progress our understanding of this relationship, we make two contributions. First, we identify three potential explanations as to why gender inequality can be associated with conflict—gender inequality norms, societal capacity, and gendered socioeconomic development—and suggest an empirical strategy to gauge the explanatory leverage of each explanation. Second, we offer a more nuanced treatment of the dependent variable at the subnational level, moving beyond a dichotomized view of armed conflict to accounting for both its level and type. We test our hypotheses using district-level data on gender inequality and conflicts in India, covering the 1989–2014 period. Our findings show that the three explanations do not produce the same outcomes in the data. We argue that this speaks to the need to adjudicate between different forms of mechanisms that can connect gender inequality to conflict. Our results show support for women's status being important for understanding a society's capacity to handle conflict nonviolently. On the negative side, gendered socioeconomic developments resulting in a male surplus create conditions conducive for armed conflict, particularly in urban areas. A more surprising finding is that the gender inequality norm, in and of itself, does not appear to have a strong effect on the risk of armed conflict. This does not mean that we can disregard the explanation, but it underlines that there can be inherent problems with this commonly used argument.