It has long been of interest to identify the phenotypic traits that mediate reproductive isolation between related species, and more recently, the genes that underpin them. Much work has focused on identifying genes associated with animal colour, with the candidate gene CYP2J19 identified in laboratory studies as the ketolase converting yellow dietary carotenoids to red ketocarotenoids in birds with red pigments. But evidence that CYP2J19 explains variation between red and yellow feather coloration in wild populations of birds is lacking. Hybrid zones between related species provide the opportunity to identify genes associated with specific traits. Here we investigate genomic regions associated with forecrown colour in red-fronted and yellow-fronted tinkerbirds across a hybrid zone in southern Africa. We sampled 79 individuals, measuring spectral reflectance of forecrown feathers as well as scoring colours from photographs. We performed a genome-wide association study to identify associations with carotenoid-based coloration, using double-digest RAD sequencing aligned to a short-read whole genome of a Pogoniulus tinkerbird that we assembled. Admixture mapping using 104,933 SNPs identified a region of chromosome 8 that includes CYP2J19 as the only locus with more than two SNPs significantly associated with both crown hue and crown score. The hybrid zone was bimodal with asymmetric backcrossing, consistent with the hypothesis that yellow-fronted females mate more often with red-fronted males than vice versa. Female red-fronted tinkerbirds mating assortatively with red-crowned males may reinforce species divergence and is consistent with the hypothesis that converted carotenoids are an honest signal of quality.

Posterior spinal surgery has the risk of perioperative respiratory complications. We describe the delayed diagnosis of an intraoperative pneumothorax in a teenage girl with idiopathic scoliosis scheduled for thoracolumbar posterior fusion. After an uneventful surgery, the oxygen saturation abruptly decreased to 65%. A chest x-ray showed a moderate pneumothorax.

The coronavirus disease (COVID-19) outbreak associated with SARS-CoV-2 was reported in December 2019 in Wuhan, China, causing a global pandemic. We report a 36-year-old male presenting with fever, a five-day dry cough, and clinical symptoms of pneumonia. His diagnosis and treatment are described.

Han River, the largest tributary of the Yangtze River in China, has experienced at least 10 large-scale algal blooms since 1992 because of eutrophication and hydrological/hydraulic regime alteration. Eutrophication control is a long-term process, but the regulation of hydrological process is a direct and effective way to prevent algal blooms. In this study, we attempted to find the difference of hydrological process between the years with and without algal blooms. Hydrological statistics and numerical simulation results show that the key high-flow processes were missing in early spring when algal blooms occur. The hydrological processes in the middle and lower Han River have undergone major changes because of the impoundment of the middle route of the South-to-North Water Diversion Project. The construction of cascade reservoirs in the middle and lower Han River, such as in Xinglong, have weakened the hydrodynamic conditions in the damming river sections, thereby providing favourable hydrological conditions for the occurrence of algal blooms. During the critical period for algal growth from January to March, the cross-sectional average velocity and discharge in the years with algal blooms were significantly lower than those years without algal blooms. The threshold levels of flow rate for algal bloom prevention at the Shayang to Xiantao River section were 1100 m3 s−1 (0.24 m s−1) and 810 m3 s−1 (0.74 m s−1), respectively. We developed the hydrological process regulation schemes on the basis of the hydrological/hydraulic thresholds according to the different sections where algal blooms occur from two aspects: a) single reservoir operations, such as full-emptying and water level fluctuation operations; and b) joint operation of cascade reservoirs and the Water Diversion Project from Yangtze to Han River.

The relative roles of rivers and refugia in shaping the high levels of species diversity in tropical rainforests has been widely debated for decades. Only recently has it become possible to take an integrative approach to answer these questions with genomic sequencing and paleo-species distribution modeling. Here, we tested the predictions of the classic river, refuge, and river-refuge hypotheses on diversification in the arboreal West and Central African snake genus Toxicodryas. We used dated phylogeographic inferences, population clustering analyses, machine learning-based demographic model selection, species paleo-distribution range estimates, and climate stability modeling to conduct a comprehensive phylogenomic and historical demographic analysis of this genus. Our results revealed significant population genetic structure within both Toxicodryas species, corresponding geographically to river barriers, and divergence times ranging from the mid to late Miocene. Our demographic and migration analyses supported our interpretation that rivers have represented strong barriers to gene flow among populations since their divergence. Additionally, we found no support for a major contraction of suitable habitat during the last glacial maximum, allowing us to reject both the refuge and river-refuge hypotheses in favor of the river barrier hypothesis. This study highlights the complexity of diversification dynamics in the African tropics and the advantage of integrative approaches to studying speciation in tropical regions.

Iatrogenic aortocoronary dissection is a rare but potentially fatal complication of coronary catheterizations. Although the incidence is comparatively low, dissection often leads to procedure failure with increased risk of myocardial infarction and death. Iatrogenic aortocoronary dissection is principally caused by disruption of intima at the ostia of the right or left coronary artery during interventional procedures and appears as luminal filling defects, the persistence of contrast or intimal tear outside the coronary lumen. Dissection could propagate in the anterograde direction causing subtotal or total occlusion of the coronary lumen or extend in the retrograde direction into the sinus of Valsalva, ascending aorta, aortic arch or descending aorta resulting in hemodynamic instability. We present a case of Right Coronary Artery dissection leading to Type-A aortic dissection suffered during diagnostic coronary catheterization. This required emergency supracoronary replacement of the ascending aorta with an aortic interposition tube graft and venous grafts to coronary arteries

This work present analytical results for the position- and momentum-space information entropies, of the 1s2-state of helium-like ions, using different interaction potentials. The potentials that we used are the Yukawa potential (YP), and the exponential-cosine-screened Coulomb potential (ECSCP). The investigated studies allow us to relate the position-space information with the momentum-space information of Shannon and Fisher, as well as Shannon entropy power, and the Fisher-Shannon information product, through different famous relations. The calculation is done using one-electron charge density of entangled two-parameter wave function. On one hand, the results that are presented for fifteen members in the helium iso-electronic sequence demonstrate with precision the effect of correlation on bare charge distributions. On the other hand, it leads to some very important results for both the correlated and uncorrelated values of the informatic entropies. Analytical formula for the momentum-space information entropies are given. The effect of the nuclear charge and the screening parameter on the informatic expressions has been studied for both potentials. Detailed computational and numerical values and characteristics of these quantities are reported here for the first time. New inequality has been proposed with Fisher’s total value to measure the correlation of two electrons.

The possible effect of plastic nanoparticles of waste origin on biological systems is still unclear, and could pose a severe threat. Model studies on the molecular level are urgently needed in order to help revealing interplay between these particles biological systems, and thereby to indicate the direction further research. In the present study, simulated annealing molecular dynamics was adjusted and applied to generate an array of conformations for a sample peptide oligoalanine possibly binding to polyethylene and nylon 6,6 nanoplastics. The resulting structures, with a diameter up to 5 nm, were investigated with the aid of static quantum chemical calculations. The obtained data unequivocally show that both plastic nanoparticles influence the relative stability of α-helix, β-hairpin and other conformations strongly. The polyethylene nanoparticle increases the stability of the helical foldamer. The nylon 6,6 nanoplastic offers strong plastic-peptide interactions at its surface, which make the unfolding of the peptide thermodynamically highly favorable. These results further underscore that nanoplastics can do significant, molecular level damage to living organisms via facilitating the misfolding and denaturation of proteins. Furthermore, it is apparent that plastics can have very different effects on living matter depending on their composition, hence experiments with any single kind of plastics (e.g. polystyrene) should not be considered generally valid for all nanoplastics.

IntroductionThe Covid-19 pandemic is posing a major worldwide problem, although at various levels in the different States.   Although Covid-19 in most cases develops benevolently and fearfully or asymptomatically, however it can present different percentages of serious complications, especially in elderly, defed or chronically ill subjects, with need of hospitalization and intensive care. Since Sars-CoV-2 is characterized by marked infectivity and a high percentage of serious complications (on average 3.6%), there has been a rapid spread, with logarithmic growth also of cases with serious complications, so that the Healthcare Systems have been subjected to high pressure, not always well sustainable. Therefore, in an attempt to contain the exponential growth of the virosis, various degrees of isolation and/or social distancing measures have been implemented in almost all States, with the closure of educational, economic, commercial and social activities (lockdown ), albeit with different timing and different intensity and duration.This has, however, led to a particularly remarkable, almost deflagrating social and economic impact.For example in Italy from 20.02.2020 in about a month the following were detected:  - stock market losses of 30%; - drop in the price of the barrel of crude oil by about 50%; - 6% decrease in GDP and subsequent reduction of 0.75% for each week of additive lock-down; - loss of about 2 million jobs, with unemployment rising to 11% of the potentially active population.1    Considering that similar, albeit different, data are found in all the other affected States and that they depend on the lockdownstrategies applied, it is understandable, that this viral spread containment strategy, although useful in an initial initial phase, cannot be sustained for too long.1   Therefore, it follows the need to propose infection containment strategies, which are reconcilable with a reduction of thelockdown , pending the development of a decisive vaccination campaign. In this perspective, we must be open to new perspectives in the preventive field, just as new perspectives are being evaluated in the therapeutic field.

Rabbit hemorrhagic disease (RHD) is an acute fatal disease caused by the lagovirus rabbit hemorrhagic disease virus (RHDV), which was first reported in 1984 in China. Strains of two different genotypes (GI.1a and GI.1c) have been detected in China to date. In 2010, a new RHDV variant with a unique genetic and antigenic profile was identified in France, designated RHDV2, which rapidly spread throughout continental Europe and nearby islands. Here, we report the first outbreak of RHD induced by RHDV2 (GI.2) in rabbit farms in the Sichuan province of China. We conducted hemagglutination tests and phylogenetic analysis of the new RHDV isolate SC2020/04, which was identified as a non-hemagglutinating strain belonging to the RHDV2 (GI.2) genogroup. Considering the serious risk of RHDV2 to the Chinese rabbit industry, the circulation of RHDV2 in the population should be carefully monitored in China.

Tilapia lake virus (TiLV) is an emerging virus that is rapidly spreading across the world. Over the past 6 years (2014–2020), TiLV outbreaks had been reported in at least 16 countries, spanning three continents, including Asia, Africa, and America. Despite its enormous economic impact, its origin, evolution, and epidemiology are still largely poorly characterised. Here, we report eight TiLV whole genome sequences from Thailand sampled between 2014–2019. Together with publicly available sequences from various regions of the world, we estimated the origin of TiLV to be between 2003–2009, 5–10 years before the first report of the virus in Israel in 2014. Our analyses consistently showed that TiLV started to spread in 2000s, and reached its peak in 2014–2016, matching well with the timing of its first report. From 2016 onwards, the TiLV population declined steadily. This could be a result of herd immunity building up in the fish population, and / or a reflection of a better awareness of the virus coupled with a better and more cautious protocol of Tilapia importation. Despite the fact that we included all publicly available sequences, our analyses revealed long unsampled histories of TiLVs in many countries, especially towards its basal diversification. This result highlights the lack and the need for systematic surveillance of TiLV in fish.

Objective: To characterize the optimal pre-(ASiR-V and post-ASiR-V for improving image quality and reducing the radiation dose in CCTA. Methods: The study was divided into two parts. In part I, 150 patients for CCTA were prospectively enrolled and randomly divided into five groups (A, B, C, D, and E), with progressive scanning from 40% to 80% pre-ASiR-V with 10% intervals and reconstructing with 70% post-ASiR-V. The SNR and CNR were calculated. Subjective image quality was assessed using a five-point scale. The radiation dose was recorded and calculated after statistical analysis by optimizing for the best pre-ASiR-V value with the lowest radiation dose while maintaining overall image quality. In part II, the images were reconstructed with the recommended optimal pre-ASiR-V values in part I (D group) was divided into six subgroups (D0-D5 with 40%-90% post-ASiR-V and interval 10%, respectively.).The SNR and CNR of D0-D5 subgroups were calculated and analyzed using one-way analysis of variance, and the consistency of the subjective scores used the k test. Results: There was no significant difference in the SNRs, CNRs, and image quality scores among A, B, C, and D groups. The SNR, CNR, and image quality scores of the E group were lower than those of the A, B, C, and D groups. The mean EDs in the B, C, and D groups were reduced by 7.01%, 13.37%, and 18.87%, respectively, when compared with that of the A group. The SNR and CNR of the D4–D5 subgroups were higher than the D0-D3 subgroups, and the image quality scores of the D4 subgroups were higher than the other subgroups. Conclusion: The wide-detector combined with 70% pre-ASiR-V and 80% post-ASiR-V significantly reduced the radiation dose of CCTA while maintaining overall image quality compared with the manufacture’s recommendation.

Exploring the dynamics of natural regeneration facilitates the understanding of the mechanisms of community assembly and biodiversity formation in tropical forests. However, there is still a lack of convincing evidence related to regeneration, especially for threatened tropical plant communities. Dacrydium pectinatum is a constructive and an endangered species in the tropical mountain forests of Hainan Island. A total of 204 regeneration plots of 5 m × 5 m were investigated along environmental axes of temperature and precipitation in the northwest (Bawangling, 90 plots), southwest (Jianfengling, 90 plots) and southeast (Diaoluoshan, 24 plots) of Hainan Island. We examined the variation in community structure, mortality, density and species richness at the three sites and analyzed the key environmental drivers that affect regeneration. The results showed that the mortality of adults, seedlings and saplings was the lowest in Diaoluoshan, followed by Jianfengling and Bawangling. The peaks in the density and species richness of regenerating individuals were limited to mid-elevations. Elevation, soil total nitrogen, soil available phosphorus, canopy density and adult density were significantly correlated with density and species richness. All findings indicate that at a broad landscape scale, variation in precipitation and temperature due to latitude, longitude and elevation is the dominant cause for the formation of the regeneration dynamic patterns along distinct environmental axes and that the intermediate environmental conditions at middle elevations contribute to regeneration. At the community level, habitat preferences related to elevational factors, soil total nitrogen, soil available phosphorus and forest gaps play a key role in regeneration success. Biological mechanisms (negative density-limiting effects) also have an important effect. We recommend various actions to improve the protection of D. pectinatum, such as the prevention of habitat destruction, appropriate thinning of high-density stands, and strengthening of niche research, and increase biodiversity.

This paper documents a mass en route mortality event of adult summer chum salmon (Oncorhynchus keta) returning to the Koyukuk River, Alaska in the Yukon River watershed. In response to reports from local communities, researchers (including the author) surveyed ca. 315 km of river on July 26 and 27, 2019 and counted 1,364 dead individuals, but this likely reflects a small fraction of the true number of fish that died. We sampled 73 carcasses to confirm death occurred prematurely prior to complete maturation and spawning, to quantify sex and length. Visual inspection revealed a substantial fraction exhibited patterns of fungal growth consistent with secondary infections of skin lesions caused by the ubiquitous natural bacterial pathogen Flavobacterium columnare. Water temperatures during the survey averaged 17.1°C and the water was approximately 85% saturated with oxygen (ca. 8.5 mg/L), which likely contributed to the stress for upstream migrants. Evidence suggests size-selective en route mortality as female migrants that died were 2% and male migrants 5% shorter than individuals that survived to their spawning grounds on Henshaw Creek. This translates to very strong estimates of natural selection using standardized selection differentials, though randomization tests of size data revealed this observed outcome of selection was expected to occur 25% of the time due to chance alone. It is unclear whether selection acts on body size directly or indirectly through correlated phenotypic traits such as run timing. The mortality event likely underpins the below average returns of summer chum salmon to the Koyukuk in 2019, suggesting an impact on spawner abundance. The future consequences of this, or potentially increasingly frequent, en route mortality events for population productivity and the extent to which genetic adaptation or adaptive phenotypic plasticity of migration behavior may facilitate persistence of these populations is unknown.

Cricket Velarifictorus micado is widely distributed in East Asia and colonized North America since 1959. It has been reported that they had two modes of life cycle and distributed in southern and northern Asia respectively. Aimed to investigate the biogeographic boundary between the two groups and the causes of differentiation, mitochondrial fragments including COI and CytB were used for phylogenetic analysis, time estimation and demographic analysis. The results showed that, (i) Haplotype network indicated that V. micado has diversified to three lineages based on COI. Individuals with egg diapause lived in northern Asia, whereas those with egg and nymph diapause lived in southern Asia, and the populations colonized North America belongs to the egg diapause group from both North and South Asia. (ii) The molecular chronograms indicated that the first diversification between individuals in the northern and southern Asia occurred during ~0.79 Ma BP in the Middle Pleistocene Transition. The second event occurred in southern individuals during ~0.49 Ma BP, when the glaciers developed in Yulong mountain (Yunnan province). (iii) V. micado has diversified to two main clades based on CytB. The individuals distributed in southern China have not been differentiated. Haplotype network indicated that the egg diapause lived in southern China most possibly originated from Yunnan, where lies at the foot of the Tibetan plateau. Our study suggested that the twice divergence of V. micado co-occurred with tendency of cooling climatic in Asia after the Mid-Pleistocene.

Grey Crowned Crane Balearica regulorum is described as an icon of Africa’s wetlands and grasslands and is listed as Endangered on the IUCN Red List of Threatened species. Efforts towards its conservation actions are nonetheless hindered by among others, lack of knowledge on factors influencing breeding productivity such as nest-site selection. Factors influencing the probability of nest-site selection were investigated at Lake Ol’ Bolossat, a 43.3 km2 wetland located in the central Kenya highlands as a breeding resident. The number and distribution pattern of breeding pairs was also determined. A total of 123 breeding pairs were recorded, 103 in the lake and 20 in the surveyed satellite wetlands thus providing the largest database of breeding Grey Crowned Cranes reported in Kenya to date. Mean breeding pair density for the lake’s marshes was 6.50±0.84 (SE) pairs/km2 with a mean distance between nests of 302.53±17.02 (SE) m. Generalized Linear Models were used to select the most important environmental variables explaining nest-sites selection. The model selection algorithm yielded a subset of 8 best models, where the most important predictor variables (i.e. those with ΔAICc <2) were determined as water depth (preferred above 50 cm), vegetation height (above 60-90 cm) and distance from the water edge (ca.100 m). Water depth and vegetation height had positive effects on nesting probability while the distance to water edge exhibits quadratic tendency. These findings provide key insight into Grey Crowned Crane nesting ecology and a basis for breeding habitat modification and management. This study underscores the importance of Lake Ol’ Bolossat as a critical breeding site and its significant role in the species’ population recovery and survival. The lake should consequently be re-gazetted as a National Park to ensure effective and sustainable control of anthropogenic activities in and around the lake in favour of Grey Crowned Crane.

Il piano di caratterizzazione costituisce uno dei primi momenti di un progetto di bonifica. Nell’ambito della caratterizzazione, si riconosce una fase di particolare rilevanza che è quella della definizione e successiva esecuzione del piano di indagini. In tale contesto, le indagini geofisiche sembrano assumere un’importanza crescente attribuibile alla loro applicazione rapida e non invasiva del suolo e alle molteplici informazioni che consentono di ottenere, tuttavia esse presentano delle limitazioni in termini di quantificazione della concentrazione di contaminante e di sensibilità delle grandezze misurate che possono quindi condurre facilmente a deduzioni errate. Per questo motivo le applicazioni più comuni prevedono una combinazione di tali metodi geofisici con indagini dirette al fine di ridurre al minimo gli errori. Nell’elaborato che segue si fornisce una descrizione generale delle indagini geofisiche e delle loro applicazioni a livello nazionale ed internazionale, approfondendo poi nello specifico l’applicazione di metodi geoelettrici nell’ambito del piano di caratterizzazione di una discarica.  

Water stress causes considerable yield loss in potato, usually considered a drought-sensitive crop. Photosynthesis is a primary target of abiotic stresses, and manipulation of photosynthetic electron distribution in chloroplasts by introducing the alternative electron carrier flavodoxin increased tolerance of model plants to multiple environmental challenges including drought, suggesting that a similar strategy could function in crops. We show herein that expression of a plastid-targeted cyanobacterial flavodoxin in potato plants protected photosynthetic activities even at a pre-symptomatic stage of drought stress. Transcriptional profiling revealed that 5-6% of leaf-expressed genes were regulated by flavodoxin in the absence of stress, representing pathways modulated by chloroplast redox status during normal growth. The majority (68.5%) of drought-responsive genes were also affected by flavodoxin, whose main effect was to mitigate changes in gene expression caused by water deficit, suggesting that flavodoxin-expressing plants suffered less stress than their wild-type siblings, and accordingly displayed an attenuated response to the adverse condition. Expression of 290 drought-responsive genes was primed in the transformants in the absence of stress, and could contribute to drought tolerance. Yield improvement under chronic water limitation was moderate but significant in flavodoxin-expressing plants, indicating that the flavoprotein has potential to improve major agronomic traits in potato.

Abstract: At the genus and species level, variation in root anatomy and architecture may interact to affect strategies of drought avoidance. To investigate this idea, root anatomy and architecture of the drought-sensitive common bean (Phaseolus vulgaris) and drought-adapted tepary bean (Phaseolus acutifolius) were analyzed in relation to water use under terminal drought. Intraspecific variation for metaxylem anatomy and axial conductance was found in the roots of both species. Genotypes with high-conductance root metaxylem phenotypes acquired and transpired more water per unit leaf area, shoot mass, and root mass than genotypes with low-conductance metaxylem phenotypes. Interspecific variation in root architecture and root depth was observed where P. acutifolius has a deeper distribution of root length than P. vulgaris. In the deeper-rooted P. acutifolius, genotypes with high root conductance were better able to exploit deep soil water than genotypes with low root axial conductance. Contrastingly, in the shallower-rooted P. vulgaris, genotypes with low root axial conductance had improved water status through conservation of soil moisture for sustained water capture later in the season. These results indicate that metaxylem morphology interacts with root system depth to determine a strategy of drought avoidance and illustrate synergism among architectural and anatomical phenotypes for root function.

A cluster of pneumonia cases of unknown origin was detected on December 31th which led to the discovery of coronavirus disease 2019 (COVID-19). Lungs are the primary site of involvement. SARS-COV-2, which is the causative agent, enters the alveolar cells using ACE2 as a receptor. Due to exposure of first cases to Wuhan’s animal market, a zoonotic transmission was suspected. Further studies suggested human to human transmission through contact and droplets. Symptoms vary from asymptomatic to acute respiratory distress syndrome and death and cases are diagnosed based on clinical and laboratory findings. Currently, there is no definitive treatment or vaccine and different antiviral and other treatments are being tested as possible therapeutic agents with different mechanisms, for example, Chloroquine, hydroxychloroquine, azithromycin, favipiravir, umifenovir, ribavirin, Ivermectin, etc.

In this paper, we study a stochastic cholera model with differential infectivity which is disturbed by both white noise and telegraph noise. Firstly, we prove that there exists a unique global positive solution to the system with any positive initial value. Then we obtain sufficient criteria for extinction of the diseases. Finally, we establish sufficient criteria for the existence and uniqueness of an ergodic stationary distribution of the positive solutions to the model by constructing a suitable stochastic Lyapunov function with regime switching. The stationary distribution implies that all the individuals can coexist and persist in the long term.

A document by suliman alfaqeih, written on Authorea.

Rational B\’{e}zier curve; Polynomial approximation; Constrained Jacobian polynomials; Hybrid curve

Metaheuristic algorithms based on the collective behavior of nature social groups, such as ants and bees, have been widely explored to solve many optimization problems in engineering and other sciences. The processing time and the chance to end up in a local optimal solution are drawbacks of these algorithms, and none has proved to outperform the others. In this paper, an improved swarm optimization technique, named Grand Tour Algorithm (GTA), based on the behavior of a peloton of cyclists, is introduced and applied to sixteen benchmarking optimization problems in the literature to evaluate its performance in comparison to the original particle swarm optimization (PSO) algorithm. Most of these benchmarking problems are tackled with a number of 20,000 variables, a really huge number inspired in the human genome. Under these conditions, GTA clearly outperforms the classical PSO. In addition, various sensitivity analyses are performed to verify the influence of the initial parameters in the GTA efficiency. It can be demonstrated that the GTA fulfils such coveted main aspects of an optimization algorithm as ease of implementation, speed of convergence, and reliability, thus confirming GTA’s improved performance.