Cover crop biomass production is more important than diversity for weed suppression

Biotic resistance theory suggests that diverse cover crop mixes may be more effective at weed suppression than a cover crop monoculture. However, evidence for this has so far been inconsistent. To investigate, we designed a trial to explicitly test the role of cover crop diversity in weed suppression by comparing eight cover crop mixes that varied in species diversity, functional diversity, and composition. Mixes contained either one, four, or eight species, in equal proportions. Three mixes contained only cereal species, three contained only legumes, and two contained a mix of cereals, legumes, and brassicas. Research was conducted on two farms in South Africa’s winter rainfall region, replicated over 2 yr. Indicators of resource uptake by each mix in terms of light, soil N, and water were measured at three time points throughout the season, approximately 50, 85, and 110 d after emergence (DAE). Aboveground biomass (dry weight) of cover crops and weeds within each mix was measured twice, at approximately 70 and 120 DAE. Regression analyses indicated that cover crop biomass was key to resource uptake and weed suppression, and that early-season N and later-season light availability had the strongest influence on weed biomass. Neither species diversity nor functional diversity affected resource uptake or weed suppression by cover crops. These results indicate that it is important to consider the competitiveness of individual species when designing cover crop mixes. Diverse mixes remain valuable to perform multiple functions but may contribute to weed problems if composed of poorly competitive species

Safety, pharmacokinetics and pharmacodynamics of a novel anti-asthmatic drug, XC8, in healthy probands

Introduction: XC8 (histamine glutarimide) is a novel agent which targets eosinophilic migration and mast cell degranulation and has shown anti-asthmatic effects in animal studies. Objective: The objective of this placebo-controlled phase 1 study was to assess the safety of oral XC8 and to evaluate its pharmacokinetic and pharmacodynamic properties. Methods: 32 healthy volunteers in three dose-escalation treatment groups (10 mg [n = 8], 50 mg [n = 8] and 200 mg [n = 16]) were randomized in a 3:1 ratio to XC8 or placebo respectively. The subjects received a single dose of the drug at Day 1 and then once-daily for 14 days (Days 8-21). Results: No severe adverse events occurred. The number of adverse events was similar in the treatment arms compared to placebo and all subjects completed the study as planned. No clinically significant changes occurred in hematologic and biochemical blood tests in subjects receiving XC8. The pharmacokinetic data showed similar dose and time dependent mean plasma XC8 concentrations after single (Day 1) and multiple (Day 21) dosing. The mean maximum concentrations were 114-1993 ng/mL after single and 115-2089 ng/mL after multiple dosing. The mean times to maximum concentration were 0.68-1.01 and 0.67-0.98 h, respectively. There was no evidence for accumulation of XC8 after multiple dosing. Conclusion: XC8 was safe and well tolerated. A phase 2 study is being performed to further evaluate the potential role of XC8 in asthma treatment.Peer reviewe

Observational Constraints on the HD 5980 Wind-Wind Collision

Se presentan observaciones recientes del sistema m´ultiple HD 5980 ubicado en la Nube Menor de Magallanes que se complementan con los resultados de observaciones efectuadas desde los a˜nos 1950s. Encontramos que la componente Star A, que actualmente posee el espectro dominante tipo Wolf-Rayet, siempre ha sido la estrella con el viento m´as intenso. Las variaciones en los perfiles de l´ıneas en emisi´on se explican con una combinaci´on de los siguientes procesos: eclipses atmosf´ericos, emisi´on y absorci´on proveniente de la zona de interacci´on de los vientos, y ocultamiento de regiones de esta misma zona. Las observaciones de 2017-2020 indican un incremento en el nivel de actividad comparado con los a˜nos 2010-2015.Analysis of spectral line profile variations observed over 6 decades in the WolfRayet system HD 5980 lead to the conclusion that Star A, the variable member of the system, has always dominated the wind collision zone (WCZ), contrary to suggestions that before 1994 the stronger wind belonged to its close companion, Star B. The observed variations are caused by a combination of physical occultations, wind eclipses and emission and absorption originating in the WCZ. The effects caused by the leading WCZ branch, which folds around Star B, are clearly seen as it crosses our line of sight to Star A during the secondary eclipse. These effects can inform on the WCZ velocity and density structures. We speculate that differences in line profiles at the same orbital phase but at different epochs may be linked to changes in the WCZ radiative properties. The 2017-2020 spectra indicate that HD 5980 was in a higher activity state than during 2010-2015.Fil: Koenigsberger, G.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Morrell, Nidia. Observatorio Las Campanas, Carnegie Institution; ChileFil: John Hillier, D.. University of Pittsburgh; Estados UnidosFil: Schmutz, Werner. No especifíca;Fil: Gamen, Roberto Claudio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Arias, Julia Inés. Universidad de La Serena; ChileFil: Barbá, Rodolfo. Universidad de La Serena; ChileFil: Ferrero, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentin

The Association Between Anemia of Chronic Inflammation and Alzheimer\u27s Disease and Related Dementias

Background: Dementia is a spectrum of neurological diseases characterized by memory impairment and cognitive decline with the pathogenesis and effective management remaining elusive. Several studies have identified a correlation between anemia and Alzheimer\u27s disease and related dementias (ADRD); however, anemia subtypes and association with ADRD have yet to be studied conclusively. Objective: To study an association between ADRD and anemia of chronic inflammation. Methods: We conducted a retrospective case-control study of the patients, diagnosed with ADRD at Brookdale Hospital. Pair-wise comparisons between means of controls and cases in terms of iron studies and laboratory results were performed using a Mann-Whitney U test. Pair-wise comparisons between anemia subgroups (moderate and severe) were performed using a Two Sample proportion Z-Test, where for each couple of normally distributed population. Results: There was a total of 4,517 (1,274 ADRD group; 3,243 Control group) patients. There was significant difference in hemoglobin 10.15 versus 11.04 [ Conclusion: We demonstrated an association between ADRD and anemia of chronic inflammation independent of age, renal function, and HgbA1C levels

Explaining the rank order of invasive plants by stakeholder groups

Debates surrounding the use of policies to avoid further spread of invasive species highlight the need to establish priorities in public resource allocations. We explore the consistency or discrepancy among stakeholder groups involved in the risk and control management of invasive species to identify the extent to which different factors influence stakeholder choices of major relevant plant invaders. Based on stakeholder ranking of invasive plants, we explore the reasons behind stakeholders' support for policy management. Data were collected in Galicia, Spain, where a catalogue of prohibited entry and trade of invasive species is currently under debate. We estimate a rank ordered logit model using information from semi-structured interviews conducted with respondents from four stakeholder groups: public administration sector, ornamental sector, research and social groups. The characteristics of plant invaders that provoke stakeholders to rank a species more highly are wide distribution of plant invaders, existence of public control programmes, use and sale of species in the ornamental sector and media coverage. The influence these aspects have in the selection of top-ranked invaders varies across different stakeholder groups and with stakeholders' level of knowledge, awareness and attitudes towards different potential policy measures. A small group of invaders are perceived as top rated by all stakeholder groups

Integrating invasive species policies across ornamental horticulture supply-chains to prevent plant invasions

1.Ornamental horticulture is the primary pathway for invasive alien plant introductions. We critically appraise published evidence on the effectiveness of four policy instruments that tackle invasions along the horticulture supply chain: pre-border import restrictions, post-border bans, industry codes of conduct and consumer education. 2.Effective pre-border interventions rely on rigorous risk assessment and high industry compliance. Post-border sales bans become progressively less effective when alien species become widespread in a region. 3.A lack of independent performance evaluation and of public disclosure, limits the uptake and effectiveness of voluntary codes of conduct and discourages shifts in consumer preference away from invasive alien species. 4.Policy implications. Closing the plant invasion pathway associated with ornamental horticulture requires government-industry agreements to fund effective pre- and post-border weed risk assessments that can be subsequently supported by widely adopted, as well as verifiable, industry codes of conduct. This will ensure producers and consumers make informed choices in the face of better targeted public education addressing plant invasions

Complete genome sequence of the filamentous gliding predatory bacterium Herpetosiphon aurantiacus type strain (114-95T)

Herpetosiphon aurantiacus Holt and Lewin 1968 is the type species of the genus Herpetosiphon, which in turn is the type genus of the family Herpetosiphonaceae, type family of the order Herpetosiphonales in the phylum Chloroflexi. H. aurantiacus cells are organized in filaments which can rapidly glide. The species is of interest not only because of its rather isolated position in the tree of life, but also because Herpetosiphon ssp. were identified as predators capable of facultative predation by a wolf pack strategy and of degrading the prey organisms by excreted hydrolytic enzymes. The genome of H. aurantiacus strain 114-95T is the first completely sequenced genome of a member of the family Herpetosiphonaceae. The 6,346,587 bp long chromosome and the two 339,639 bp and 99,204 bp long plasmids with a total of 5,577 protein-coding and 77 RNA genes was sequenced as part of the DOE Joint Genome Institute Program DOEM 2005

Swiss public health measures associated with reduced SARS-CoV-2 transmission using genome data

Genome sequences from evolving infectious pathogens allow quantification of case introductions and local transmission dynamics. We sequenced 11,357 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes from Switzerland in 2020 - the sixth largest effort globally. Using a representative subset of these data, we estimated viral introductions to Switzerland and their persistence over the course of 2020. We contrasted these estimates with simple null models representing the absence of certain public health measures. We show that Switzerland's border closures de-coupled case introductions from incidence in neighboring countries. Under a simple model, we estimate an 86-98% reduction in introductions during Switzerland's strictest border closures. Furthermore, the Swiss 2020 partial lockdown roughly halved the time for sampled introductions to die out. Last, we quantified local transmission dynamics once introductions into Switzerland occurred, using a phylodynamic model. We found that transmission slowed 35-63% upon outbreak detection in summer 2020, but not in fall. This finding may indicate successful contact tracing over summer before overburdening in fall. The study highlights the added value of genome sequencing data for understanding transmission dynamics

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe