Our understanding of the mechanisms routing precipitation inputs to evapotranspiration and streamflow in catchments is still very fragmented, particularly in the case of saturated flows. Here we explore five mechanisms by which plants and streams compete with each other for water, based on multiple scales of observations in a flat semiarid sedimentary catchment of central Argentina subject to abrupt hydrological transformations. Since the 80s, the “El Morro” catchment (1334 km2, -33.64°, -65.36°) experienced a fast expansion of crops over native forests and grasslands, rapid water table level rises (~0.3 m y-1), spontaneous expansion of wetlands and permanent streams by groundwater sapping. Based on episodic and continuous groundwater level, stream flow, and remote sensing data we show that plants not only take away water from streams by drying the unsaturated zone (mechanism 1), but by tapping the saturated zone in the expanding waterlogged environments (mechanism 2) and in the upland environments that remain uncultivated and display increasing tree cover (mechanism 3). Conversely, streams take away water from plants through pulsed bed-deepening and water table depression (mechanism 4), and riparian and wetland zones burying with fresh sediments (mechanism 5). While earlier work established widespread support for mechanisms 1 preventing stream formation, diurnal and seasonal fluctuations of water table levels and base streamflow records in this study proved the importance of mechanisms 2 and 3 under the current high-water table conditions. These data together with remotely-sensed greenness showed a growing but localized relevance of mechanism 4 and 5 as the stream network developed. The distinction of recharge- vs. topography-controlled groundwater systems is useful to organize the interplay of these concurrent mechanisms. Findings point to the unsaturated-saturated contact zone as a crucial and dynamic hub for water partition and for ecological, geomorphological, and hydrological knowledge integration.

Blackgram [Vigna mungo (L.) Hepper] is an important legume crop with good quality dietary proteins and vitamins. Low production of blackgram in the chromium rich soil of Odisha is a serious concern against its demand. Chromium (VI) was tested on V. mungo var. B3-8-8 at 100, 150, 200, 250 and 300 µM concentration on growth, anti-oxidative enzymes and chromium content at 15, 30 and 45 d of treatments. Seed germination and growth decreased with increase dose and duration. Cr uptake induced oxidative burst with significant increase of osmolytes in cell level to a greater amount in lower doses but failed to adjust homeostasis at higher dose. Increase of GPX and SOD and decrease of CAT contain was found in dose dependent manner. Increased protein content was observed in <200 µM Cr concentration whereas, significant decrease of protein was noted thereafter. Down regulation of proteins (29.2 kDa and 32.6 kDa) was observed at >250 µM of Cr. Total Cr uptake was greater in root than in shoot which might be due to poor translocation of heavy metal or detoxification. Thus, blackgram able to maintain homeostasis at lower concentrations of Cr by activating the cascade of enzymes following cellular detoxification mechanism.

Background. Standard of care for chronic spontaneous urticaria (CSU) includes second-generation H1-antihistamines (SGAH) but is often ineffective even with four-times the FDA-recommended dose. Urticarial lesions are commonly characterized by increased lymphocytes with perivascular eosinophilic infiltrates implying a role for the interleukin-5 (IL5). Objective. This study investigated the effects of benralizumab, an anti-IL5-receptor-alpha monoclonal antibody, in human subjects with SGAH-unresponsive CSU that completed all study visits. Methods. A repeated-measures, 24-week study was conducted at an urticaria specialist clinic where SGAH-unresponsive CSU patients (3 males and 9 females; age range, 32-65 years) having a median weekly Urticaria Activity Score (UAS7) of 4 and pruritus severity ≥2 were enrolled. After a baseline run-in period, subjects were treated with a subcutaneous placebo dose followed by benralizumab 30mg subcutaneously every month (×3 doses) followed by two off-medication monthly-visits. The primary and exploratory endpoints were the change from baseline in UAS7 and Chronic Urticaria Quality-of-Life Score (CU-QoLTS) respectively. Secondary endpoints included peripheral blood eosinophils (eos%) and basophils, skin eosinophilia, and differentially expressed genes (DEGs) in blood before- and after benralizumab. Results. UAS7 and CU-QoLTS significantly improved post-benralizumab compared to baseline scores in 7 of 9 subjects completing the study. Clinical improvements correlated with reduction in eos% and inflammatory cell infiltrates in skin lesions. Biologic pathways, regulated by DEGs, involved IL-5R activity, tryptophan metabolism and Siglec-8 expression. Conclusion. Benralizumab was clinically efficacious in the treatment of subjects with SGAH-refractory CSU which correlated with several DEGs in blood. This study supports the use of benralizumab for CSU treatment.

ABSTRACT Backgrounds Over decades median sternotomy has a been a gold standard approach for treatment of isolated multivessel coronary artery disease but this traditional approach has been associated with sternal wound healing complications leading to remarkable morbidity and mortality. Our aim was to describe our technique of left anterior minithoracotomy through fourth intercostal space for treatment of patients with multivessel coronary lesions . Methods Our experience includes 62 consecutive patients who were operated with the same surgical team. Left internal thoracic artery was harvested in all patients by the aid of rib retractor. All patients were operated under cardiopulmonary bypass (CPB) with blood cardioplegia through left minianterior thoracotomy of 5cm-7cm. All saphenous vein grafts were harvested endoscopically. Results We had no mortality, no early postoperative myocardial infarction was observed . Only one patient was converted to sternotomy(1.6 %). Two patients had postoperative atrial fiblillation(3.2%), 1 patient suffered postoperative stroke(resolved without neurologic deficit)(1.6%), 4 patients had revision due to postoperative bleeding(6.4%) perfomed through the same incision(no sternotomy was required). The mean number of bypass was 3.6 ±0.8, cross clamping time was 95.7 ± 41.0 minutes, cardiopulmonary bypass time was 159.2 ± 46.5 minutes,entubation time was 6.7± 1.9 hours, intensive care unit(ICU) stay was 1.2± 0.6 days, hospital stay was 5.3± 2.7 days. Conclusion CABG via left anterior thoracotomy is equally effective as traditional sternotomy but less invasive,quick recovery and is so promising in terms of less morbidity and mortality. It might be an alternative to sternotomy incision and percutaneous techniques

The best suggestion for COVID-19 in a non-infected pregnant population is still prevention: a commentaryRui-Hong Xue1, He-Feng Huang2,3,4,5

Artificial intelligence and big data are more and more used in medicine, either in prevention, diagnosis or treatment, and are clearly modifying the way medicine is thought and practiced. Some authors argue that the use of artificial intelligence techniques to analyze big data would even constitute a scientific revolution, in medicine as much as in other scientific disciplines. Moreover, artificial intelligence techniques, coupled with mobile health technologies, could furnish a personalized medicine, adapted to the individuality of each patient. In this paper we argue that this conception is largely a myth: what health professionals and patients need is not more data, but data that are critically appraised, especially to avoid bias. The validity of data and the validity of inferences drawn from the data by algorithms are indeed a major epistemic issue, though rarely addressed as such by health professionals or philosophers of medicine. Considering the history of epidemiology, specifically the formation of the concept of bias, we propose three research priorities concerning the use of artificial intelligence and big data in medicine.

Objective: Description of characteristics, risk factors, management strategies and maternal, obstetric and neonatal outcomes of SARS-CoV-2 infected pregnant women in the Netherlands. Design: Multi-centre prospective nationwide population-based cohort study. Setting: Nationwide. Population: All pregnant women in the Netherlands with confirmed SARS-CoV-2 infection in home-isolation or admitted to hospital between March 1st, 2020 and August 31st, 2020. Methods: Pregnant women with positive PCR or antibody tests were registered using the Netherlands Obstetrics Surveillance System. Testing occurred according to national guidelines (selective testing). Data from the national birth registry (Perined) and Dutch National Institute for Public Health and the Environment (RIVM) were used as reference. Main Outcome Measures: Incidence of pregnant women with SARS-CoV-2 infection. Maternal, obstetric and neonatal outcomes including hospital and critical care admission, clinical management and mode of birth. Results: Of 312 registered women, 65 (20%) were admitted to hospital, of whom 5 (2%) to intensive care and 9 (14%) to obstetric high care units. Risk factors for admission were non-Caucasian background (n=28; OR 6.67, 95%CI 4.08-10.90) and being overweight or obese (n=38; OR 2.64, 95%CI1.51 to 4.61). Hospital and intensive care admission were higher compared to age-matched infected women (respectively, OR 14.57, 95%CI 10.99-19.03 and OR 5.02, 95%CI 2.04-12.34). One maternal death occurred. Caesarean section after labour onset was increased (OR 2.50; 95%CI 1.57-3.97). Conclusions: Pregnant women with SARS-CoV-2 infection are at increased risk of hospital admission, ICU admission and caesarean section. Funding: No funding was received. Keywords: Pregnancy, COVID-19, SARS-CoV-2, Pregnancy complications, Pregnancy outcome, Obstetric surveillance system.

ABSTRACTIt is sad to hear discussions among the president of the International Union of Immunological Societies and the presidents of 15 other national immunology societies1. Their actions against COVID-19 to individual government leaders were not swift. Inconsistent and slow prevention against COVID-19 may prolong the pandemic worldwide. The best surveillance should be implemented in the world as soon as possible.KEYWORDSCOVID-19; SARS; airborne; air travel; receptor ACE2; asymptomatic and presymptomaticIt is sad to hear discussions among the president of the International Union of Immunological Societies and the presidents of 15 other national immunology societies1. Their actions against COVID-19 to individual government leaders were not swift. SARS-CoV-2 was named after SARS by WHO on Feb. 1120202. From Feb. 11, expert scientists who should know the past lessons from SARS 17 years ago and MERS 8 years ago respectively should disseminate that SARS-Cov-2 is an airborneinfection virus which spreads person to person 3,4. They should also disseminate how to effectively prevent the airborne infection transmission. They should also ban air travel 4.Hoffmann et al. discovered that SARS-CoV-2 uses the SARS-CoVreceptor ACE2 for host cell entry on April 16in 20205.For mitigating the COVID-19 pandemic, the expert scientists should disseminate to the world on isolation of COVID-19asymptomatic and presymptomatic patients.They should also disseminate there is still no vaccine for SARS and MERS despite dozens of attempts to develop them6. Since there is no vaccine for COVID-19, urgent isolation is an only strategy for mitigating the pandemic where the robust surveillance withpatient’s detection plays a key role.Inconsistent and slow prevention against COVID-19 may prolong the pandemic worldwide. The best surveillance should be implemented in the world as soon as possible.References:1.Osier, F., Ting, J.P.Y., Fraser, J. et al. The global response to the COVID-19 pandemic: how have immunology societies contributed? Nat Rev Immunol 20, 594–602 (2020).https://doi.org/10.1038/s41577-020-00428-42.https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it3.https://www.who.int/csr/resources/publications/ICHC_booklet_FINAL.pdf4. https://www.who.int/health-topics/severe-acute-respiratory-syndrome#tab=tab_15. Hoffmann et al., 2020, Cell,181,271–280, April 16, 2020https://doi.org/10.1016/j.cell.2020.02.0526.https://www.mountsinai.org/about/newsroom/2020/itn-there-was-no-vaccine-for-sars-or-mers-will-there-be-one-for-the-new-coronavirus-josephine-ma-and-simone-mccarthy

Objective: To determine the optimal effective dose pituitrin in laparoscopic myomectomy for uterine leiomyoma. Design: Prospective, double-blinded, randomized controlled trial. Setting: A tertiary women’s hospital in China. Population: A total of 118 women who underwent laparoscopic myomectomy. Methods: Women were randomly divided into four groups to receive 0, 2, 4, or 6 units of pituitrin in the leiomyoma (groups 0U, 2U, 4U, and 6U, respectively). Main outcome measures: Rate of satisfactory surgical field, hemodynamic changes, total surgical time and blood loss were recorded. Results: The rate of sastisfactory surgical field was 6.7%, 72.4%, 89.7% and 93.3% in groups 0U, 2U, 4U, and 6U, respectively; it was higher in groups 2U, 4U, and 6U than group 0U, but there were no significant differences among the groups 2U, 4U, and 6U. The blood loss was higher in group 0U than that in groups 2U, 4U, and 6U (). Pituitrin was associated with a transient decrease in blood pressures and increase in heart rate in a dose-dependent fashion, with more pronounced changes in groups 4U and 6U and these groups also required higher amount of vasoactive drug to correct hemodynamic changes (p<0.05). Conclusions: Use low-dose pituitrin (2 units) provides a satisfactory surgical field with minimal hemodynamic changes.

Due to migration and travels, obstetricians are increasingly faced with a globalized setting and should adapt their daily clinical approach to the modifications of tropical infections epidemiology. This paper is focused on five emerging infectious diseases, namely Chagas disease, HTLV-1 infection, malaria, schistosomiasis and Zika virus infection, having a high prevalence in migrant populations and which can affect international travelers. These diseases frequently pass unrecognized since they are characterized by few symptoms during pregnancy, however they may cause a relevant maternal, fetal and neonatal impact. Specific diagnostic and treatment options are available but are rarely used during routine obstetrical practice.

We consider a nonlinear Dirichlet problem driven by the $(p,q)$-Laplacian and with a reaction which is dependent on the gradient. We look for positive solutions and we do not assume that the reaction is nonnegative. Using a mixture of variational and topological methods (the “frozen variable” technique), we prove the existence of a positive smooth solution.

Abstract A 39-year-old male patient from a county health facility presented to our department with a one-year history of progressive exertional chest tightness (NYHA class III-IV), which resolved completely within five to six minutes of rest. Both motion and static imaging results revealed a rare solitary Quadricuspid aortic valve (QAV) with severe aortic valve regurgitation. The QAV was replaced with mechanical prosthetic valve via mini-superior sternotomy on cardiopulmonary bypass machine. The patient was reviewed a month after operation, and assessment revealed that he had reverted to NYHA class-I. A rare congenital lesion such as QAV, repair may not be the best option due to lack of long-term data on longevity. Additionally, choice of a mechanical prosthetic valve guarantees unwanted re-operations associated with possible failure of bioprosthetic valves.

In general, the basic reproduction number (R0) cannot be explicitly calculated for HIV(Human Immunodeficiency Virus) infection model with age-structured in a infinite dimensional spaces. To find R0, we need to transform the HIV model into a finite-dimensional space. In this paper, we are absorbed in numerical approximation of R0, which is the non-negative dominant eigenvalues of the positive irreducible matrices whose spectrum radius is defined as the next generation matrix. The linear operators generated by infected population are discretized into ordinary differential equations in a finite n-dimensional space. Thus, the abstract problem is transformed to find the positive dominant eigenvalues of the next generation matrix, we obtain a threshold R_0,n. Based on the spectral approximation theory, we show that R_0,n →R0 as n →+∞. Finally, by virtue of a numerical simulation, we demonstrate the results of the theorem.

Introduction: Gait speed can be applied, predicting outcomes associated with hospital stay such as length of stay and/or discharge. Despite these studies that correlate gait speed with the aforementioned outcomes, when we deal with cardiac surgery there is a gap. Objective: Verify whether gait speed is associated with the risk of hospital readmission in the postoperative period of coronary artery bypass grafting. Methodology: This is a prospective cohort study. In the preoperative period, all patients underwent a 10-meter gait speed test and repeated at hospital discharge. After the repetition of the gait speed test, patients were divided into two groups: slow and non-slow. Those who were not discharged walked less than 1.0 m/s occupied the slow group and those who were above 1.0 m/s were classified as not slow. Patients were followed for six months to observe the primary outcome, which was the need for hospital readmission. Results: The 6 months rate of readmission was 58%(14/24;95%CI49%to80%) among slow walkers and 17% (6/36;95%CI13%to46%) among non-slow walkers(p=0.002).In univariate analysis, gait speed, treated as a continuous variable, was associated with the primary outcome (HR0.6;95%CI0.2to0.9), while age, gender, BMI, MV and CPB time were not. In the multivariate model including age, gender, BMI, MV and CPB time, gait speed remained the only variable associated with readmission (multivariate HR:0.5,95%CI0.1to0.7p=0.02). Conclusion: Our data suggest that gait speed is associated with hospital readmission in patients undergoing to coronary artery bypass grafting.

Objective: To assess the relationship between number of oocytes retrieved during social egg freezing (SEF) cycles with various clinical, biochemical and radiological markers; e.g. age, body mass index (BMI), baseline anti-Mullerian hormone (AMH), antral follicle count (AFC), Oestradiol level (E2) and total number of follicles ≥12mm at trigger. Main outcome measures: To describe the characteristics and outcomes of women who underwent SEF. Methods: A retrospective cohort of women embarking on SEF between 2008 and 2018 from a single London UK fertility clinic. Results: 483 stimulation cycles were undertaken in 373 women. The median age at freeze was 38 (26-47) years. The median numbers of oocytes retrieved per cycle was 8 (0-37), and total oocytes cryopreserved 8 (0-45) per woman. BMI, E2 level and number of follicles ≥12mm at trigger were all significant predictors of oocyte yield. Multivariate analysis confirmed no significant relationship between AFC or AMH, whilst on univariate analysis statistical significance was proven. 36 women returned to use their oocytes, with 41 autologous egg thaw cycles undertaken. 12 successful livebirths were achieved by 11 women. The overall livebirth rate was 26.8% per cycle. No livebirths occurred in women ≥40 years old and 82% of all livebirths were in women aged 36-39 at freeze. Conclusions: This study demonstrates clinical, biochemical and radiological markers can predict oocyte yield in SEF cycles. However, subsequent reproductive outcomes highlight women embarking upon SEF should be encouraged to do so before the age of 37 years, and no later than 40 to optimise successful livebirth.

The mitochondrial F1FO-ATPase in the presence of the natural cofactor Mg2+ acts as the enzyme of life by synthesizing ATP, but it can also hydrolyze ATP to pump H+. Interestingly, Mg2+ can be replaced by Ca2+, but only to sustain ATP hydrolysis and not ATP synthesis. When Ca2+ inserts in F1, the torque generation built by the chemomechanical coupling between F1 and the rotating central stalk was reported as unable to drive the transmembrane H+ flux within FO. However, the failed H+ translocation is not consistent with the oligomycin-sensitivity of the Ca2+-dependent F1FO-ATP(hydrol)ase. New enzyme roles in mitochondrial energy transduction are suggested by recent advances. Accordingly, the structural F1FO-ATPase distortion driven by ATP hydrolysis sustained by Ca2+ is consistent with the permeability transition pore signal propagation pathway. The Ca2+-activated F1FO-ATPase, by forming the pore, may contribute to dissipate the transmembrane H+ gradient created by the same enzyme complex.

BACKGROUND: Acute lymphoblastic leukemia(ALL) has survival rates of greater than 90% in developed nations. However various sociodemographic factors adversely affect outcome rates in low and middle income countries(LMIC). OBJECTIVE: To study induction outcome of ALL and various factors affecting it. METHODS: This was a prospective cohort study which enrolled 73 children up to age of 18 years with newly diagnosed ALL registered in our newly-established pediatric oncology division over duration of 2.5 years. Sociodemographic and clinical data was collected. Outcome was assessed using morphological remission, minimal residual disease(MRD) and mortality rate. RESULTS: Of the142 children with malignancies registered, 73 were ALL. Mean age was 7.09±4.07 years, male to female ratio 1.15:1. 15(44.12%) had severe acute malnutrition (SAM) and 14(41.17%) had moderate acute malnutrition (MAM). 27(69.23%) children were undernourished. 62(84.93%) were B-ALL, 11(15.07%) T-ALL. 28.77% had WBC counts greater than 50X109/L. t(12;21) was the most common cytogenetic abnormality. 65.76% of the patients belonged to lower socioeconomic status. There were 10 dropouts. 59(93.65%) patients completed induction of which 100% attained morphological remission and 54(91.53%) were MRD negative. There were 4 mortalities, 2(50%) due to sepsis and 2(50%) due to hemophagocytic lymphohistiocytosis(HLH). 41(65.08%) children had morbidities during induction, febrile neutropenia being the commonest. CONCLUSIONS: Successful induction outcome rates at par with high income countries(HIC) can be achieved even in resource-limited settings of LMIC with support from government schemes and NGOs. Decentralized cancer care centres can effectively pave the way in reducing cancer mortality in children of lower socioeconomic status residing in rural areas.

Background The MAPK pathway, is a signal transduction pathway involved in the oncogenesis of a variety of pediatric tumors. The clinical use of BRAF inhibitors and MEK inhibitors is increasingly used in oncology practice. The toxicity profile of these drugs in the pediatric population, particularly in relation to development, growth and sexual maturation remains insufficiently studied. Procedure This study includes 22 pediatric patients with molecularly confirmed MAPK pathway driven tumors treated with MEK or BRAF between August 2014 and March 2020. Throughout treatment they underwent regular laboratory, endocrine, cardiac, ophthalmic and dermatologic evaluation. Toxicity was recorded and evaluated according to CTCA v4. Results Overall an adverse event frequency of 86% was encountered. Dermatological disorders accounted for 68% of the adverse events. Overall 8 patients suffered from severe adverse events including Erythema Nodosum, PLEVA-like rash, osteoporosis, Sarcoid-like massive lymphadenopathy, retinal toxicity and elevated liver enzymes & CPK. Four patients discontinued treatment as a result of adverse events. In this cohort we did not encounter any treatment-related abnormalities of sexual maturation or gonadal function nor statistically significant growth retardation, however a slower than expected growth rate was observed in one patient. In addition dose-dependent, non-symptomatic and within normal range for age decreased cardiac SF% was noted in two patients treated with MEK inhibitor. Conclusion Treatment with BRAF and MEK inhibitors was shown to be generally safe, we report drug tolerability of 82%. However, further prospective studies should be preformed to are characterize the full scope of side effects in the pediatric population.

Background and Purpose The human gut bacterium Akkermansia muciniphila has been increasingly recognized for its therapeutic potential in treating metabolic disorders. However, its efficacy in preventing non-alcoholic fatty liver disease (NAFLD) and the mechanism involved in its well-known metabolic actions are unknown. The present study explored the therapeutic effect and novel mechanism of A. muciniphila in intervening NAFLD. Experimental Approach The anti-NAFLD activity of A. muciniphila was evaluated in an obese mouse model induced by high-fat and cholesterol (HFC) diets using three different interventions. The gut microbiota composition, beneficial metabolic effects in the gut-liver axis were explored. The level and beneficial metabolic effects of L-aspartate in vitro and in vivo were further determined. Key Results Mice treated with A. muciniphila efficiently reversed NAFLD in the liver, such as hepatic steatosis, inflammatory, and liver injury. These therapeutic effects persisted after long-term drug withdrawal and were slightly weakened in a germ-free mouse model. A. muciniphila treatment efficiently increased mitochondrial oxidation and bile acid metabolism in the gut-liver axis, ameliorated oxidative stress- induced cell apoptosis in the gut, leading to the reshaping of the gut microbiota composition. These metabolic improvements occurred with increased L-aspartate levels in the liver that transported from the gut. The administration of L-aspartate in vitro or in mice displayed the similar beneficial metabolic effects mentioned above. Conclusion and Implications The anti-NAFLD activity of A. muciniphila correlated with lipid oxidation and improved gut-liver interactions through regulating L-aspartate metabolism. A. muciniphila would be a potent agent for clinical intervention in NAFLD.

Drowning Sie Chong Doris Lau Department of Paediatrics, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia

Climate change is thought to facilitate the introduction and spread of invasive alien species. The present study aimed at examining the present and future invasive potential of S. didymobotrya under the changing climatic conditions using the Species Distribution Model. Two representative concentration pathways (RCP4.5, and RCP8.5), and seven bioclimatic including one topographic variable were used to simulate the current and future (2050s and 2070s) distribution of S. didymobotrya invasion in Africa. The model performance evaluation is done based on, the area under the receiver operating characteristic curve (AUC) and true skills statistics (TSS). The results of the study showed that under current climatic conditions 18% of the continent of Africa is suitable for S. didymobotrya establishment and invasion. Eastern Africa is seen as the most suitable habitats for S. didymobotrya invasion followed by southern Africa. The predicted model shows that in the 2050s under RCP4.5 and RCP8.5, 3.4% and 3.17% of the continent will be highly suitable for S. didymobotrya invasion, respectively. In the 2070s, the highly suitable area for the species is predicted to be 3.18 % and 2.73% in RCP4.5 and RCP8.5, respectively. The low to moderate suitability under RCP 4.5 and RCP8.5 in the 2050s is projected as 17.4 % and 20.5 % and this area is increased in the 2070s to19.11% and 22.82 for the RCP 4.5 and RCP 8.5, respectively. The results of this study indicate a significant increase in the vulnerability of habitat for S. didymobotrya invasion under the future climatic conditions. Our current finding suggests the future biodiversity conservation strategy and policy direction should focus on the means and strategy of limiting the rate of expansion of invasion and distribution.

To the Neotropical genus Acrocomia (Arecaceae) is attributed eight species with a wide distribution in America. A. aculeata and A. totai are the most important species because of their high economic potential for oil production. However, there is no consensus in their classification as different taxons and their distinctiveness is particularly challenging due to morphological similarities with large plasticity of the traits. In addition, there is doubt about the occurrence of interspecific hybrids between both species. In this study, we applied a genetic population approach to assessing the genetic boundaries, diversity and to identify interspecific hybrids of A. aculeata and A. totai. Thirteen loci of simple sequence repeat (SSR) were employed to analyze twelve populations representing a wide distribution of species, from Minas Gerais, Brazil to Formosa, Argentina. Based on the Bayesian analysis (STRUCTURE and NewHybrids) and Discriminant Analysis of Principal Components (DAPC), our study supports the recognition of A. aculeata and A. totai as two species and the estimates of genetic parameters revealed more genetic diversity in A. totai (HE=0.551) than in A. aculeata (HE=0.466). We obtained evidence of hybridization between the species and that admixed individuals were assigned as F2 hybrids. In conclusion, this study showed the usefulness of microsatellite markers to elucidate the genetic boundaries of A. aculeata and A. totai, supporting their classification as different species and increase our knowledge about genetic diversity at the level of populations and species. The results are essentials to establish strategies for the adequate management, conservation, and domestication of both species.

Tilia cordata Mill. is a valuable tree species enriching the ecological values of the coniferous dominated boreal forests in northerly Europe. Following the historical decline, spreading of Tilia sp. is challenged by the elevated inbreeding and habitat fragmentation. We aimed to identify the main factors affecting the genetic potential of Tilia cordata for natural expansion by studying the geographical distribution of genetic diversity of Tilia cordata in semi-boreal forests of Lithuania. We used 14 genomic microsatellite markers to genotype 543 individuals from 23 wild growing populations of Tilia cordata in Lithuania. We found that Tilia cordata retained high levels of genetic diversity (population Fis = 0 to 0.15, Ho = 0.53 to 0.69, He = 0.56 to 0.75). AMOVA, Bayesian clustering and Monmonier’s barrier detection indicate weak but significant differentiation among the populations (Fst = 0.037***) into geographically interpretable clusters of (a) western Lithuania with high genetic heterogeneity but low genetic diversity, bottleneck effects, (b) peaking values of genetic diversity of Tilia cordata on rich and most soils of midland lowland, and (c) the most differentiated populations on poor soils of the coolest north-eastern highland possessing the highest rare alle frequency but elevated inbreeding and bottleneck effects, presumably, due to sub-structuring. We conclude that the genepool of Tilia cordata in Lithuania contains (a) the autochthonous populations of high genetic diversity representing the pre-historical genepools, that can be promoted, and (b) the escapes from urban sources of low diversity, that must be contained.

Exploring vegetation distribution spatial patterns facilitates understanding how biodiversity addresses the potential threat of future climate variability, especially for highly diverse and threatened tropical plant communities, but few empirical studies have been performed over various environmental scales. In this study, we used species-based and phylogeny-based methods to analyze the α- and β-diversity pattern variation in Dacrydium pectinatum communities and its key drivers along elevation and geographical gradients across three national nature reserves in Bawangling, Diaoluoshan and Jianfengling. Our study indicates that the species and phylogenetic α-diversity patterns presented consistent decreasing with elevation, with the peak occurring at low elevations. Environmental filtering caused by decreases in limiting factors, such as temperature, precipitation, soil organic matter, soil phosphorus, and light, is the main reason for the decline in diversity at high elevations, whereas low-elevation areas are affected by various factors, such as environmental filtering and similarity limitations. Species and phylogenetic β-diversity changes are closely related to environmental filtering and dispersal limitation, but the latter is key in community assembly at the heterogeneous spatial scale. In conclusion, combining species-based and phylogeny-based methods to explore the biogeographic patterns of tropical plant communities helps provide convincing evidence and confirms that the relative contributions of niche and neutral theory in the assembly process vary along environmental gradients. Though the D. pectinatum community constitute a floristically integrated unit, the genetic relationships between species are relatively far, and co-evolution to promote species coexistence is difficult when faced with habitat pressure. Hence, we believe that species coexistence in tropical plant communities requires mild environmental conditions, and low temperatures, precipitation, soil nutrients and light will aggravate environmental filtering and species competition. We also recommend strengthening the construction and management of nature reserves and the exploration of biodiversity formation mechanisms, which are crucial for biodiversity conservation in endangered tropical plant communities.