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Archaeological sites in Northwest Africa are rich in human fossils and artefacts providing proxies for behavioural and evolutionary studies. However, these records are difficult to underpin on a precise chronology, which can prevent robust assessments of the drivers of cultural/behavioural transitions. Past investigations have revealed that numerous volcanic ash (tephra) layers are interbedded within the Palaeolithic sequences and likely originate from large volcanic eruptions in the North Atlantic (e.g. the Azores, Canary Islands, Cape Verde). Critically, these ash layers offer a unique opportunity to provide new relative and absolute dating constraints (via tephrochronology) to synchronise key archaeological and palaeoenvironmental records in this region. Here, we provide an overview of the known eruptive histories of the potential source volcanoes capable of widespread ashfall in the region during the last ~300,000 years, and discuss the diagnostic glass compositions essential for robust tephra correlations. To investigate the eruption source parameters and weather patterns required for ash dispersal towards NW Africa, we simulate plausible ashfall distributions using the Ash3D model. This work constitutes the first step in developing a more robust tephrostratigraphic framework for distal ash layers in NW Africa and highlights how tephrochronology may be used to reliably synchronise and date key climatic and cultural transitions during the Palaeolithic.
Various water-based heater-cooler devices (HCDs) have been implicated in nontuberculous mycobacteria outbreaks. Ongoing rigorous surveillance for healthcare-associated M. abscessus (HA-Mab) put in place following a prior institutional outbreak of M. abscessus alerted investigators to a cluster of 3 extrapulmonary M. abscessus infections among patients who had undergone cardiothoracic surgery.
Methods:
Investigators convened a multidisciplinary team and launched a comprehensive investigation to identify potential sources of M. abscessus in the healthcare setting. Adherence to tap water avoidance protocols during patient care and HCD cleaning, disinfection, and maintenance practices were reviewed. Relevant environmental samples were obtained. Patient and environmental M. abscessus isolates were compared using multilocus-sequence typing and pulsed-field gel electrophoresis. Smoke testing was performed to evaluate the potential for aerosol generation and dispersion during HCD use. The entire HCD fleet was replaced to mitigate continued transmission.
Results:
Clinical presentations of case patients and epidemiologic data supported intraoperative acquisition. M. abscessus was isolated from HCDs used on patients and molecular comparison with patient isolates demonstrated clonality. Smoke testing simulated aerosolization of M. abscessus from HCDs during device operation. Because the HCD fleet was replaced, no additional extrapulmonary HA-Mab infections due to the unique clone identified in this cluster have been detected.
Conclusions:
Despite adhering to HCD cleaning and disinfection strategies beyond manufacturer instructions for use, HCDs became colonized with and ultimately transmitted M. abscessus to 3 patients. Design modifications to better contain aerosols or filter exhaust during device operation are needed to prevent NTM transmission events from water-based HCDs.
Mental health problems are elevated in autistic individuals but there is limited evidence on the developmental course of problems across childhood. We compare the level and growth of anxious-depressed, behavioral and attention problems in an autistic and typically developing (TD) cohort.
Methods
Latent growth curve models were applied to repeated parent-report Child Behavior Checklist data from age 2–10 years in an inception cohort of autistic children (Pathways, N = 397; 84% boys) and a general population TD cohort (Wirral Child Health and Development Study; WCHADS; N = 884, 49% boys). Percentile plots were generated to quantify the differences between autistic and TD children.
Results
Autistic children showed elevated levels of mental health problems, but this was substantially reduced by accounting for IQ and sex differences between the autistic and TD samples. There was small differences in growth patterns; anxious-depressed problems were particularly elevated at preschool and attention problems at late childhood. Higher family income predicted lower base-level on all three dimensions, but steeper increase of anxious-depressed problems. Higher IQ predicted lower level of attention problems and faster decline over childhood. Female sex predicted higher level of anxious-depressed and faster decline in behavioral problems. Social-affect autism symptom severity predicted elevated level of attention problems. Autistic girls' problems were particularly elevated relative to their same-sex non-autistic peers.
Conclusions
Autistic children, and especially girls, show elevated mental health problems compared to TD children and there are some differences in predictors. Assessment of mental health should be integrated into clinical practice for autistic children.
In a survey of infection prevention programs, leaders reported frequent clinical and infection prevention practice modifications to avoid coronavirus disease 2019 (COVID-19) exposure that exceeded national guidance. Future pandemic responses should emphasize balanced approaches to precautions, prioritize educational campaigns to manage safety concerns, and generate an evidence-base that can guide appropriate infection prevention practices.
Russian thistle, also known as tumbleweed (Salsola spp.), is a problematic invasive plant found on natural and working landscapes. On a California rangeland, we tested the singular and interactive treatments of grazing, herbicide, and seeding to determine how these approaches might influence Salsola cover across a 5-yr experiment. Total Salsola cover declined by 3% annually during the study. A single spring treatment of chlorsulfuron + 2,4-D followed by glyphosate applied in the fall just before seeding, and then 2,4-D the following spring, significantly reduced Salsola cover compared with the untreated control. Seeded forage species cover increased over time and was significantly higher than seeded native species cover at 5 yr after seeding. However, the seeding treatment had no effect on Salsola cover. Although grazing did not reduce Salsola cover, due to the beneficial effects of grazing on reducing other nonnative species, this study supports the use of an integrated approach of herbicide application, grazing, and seeding to achieve management goals on an arid working landscape.
Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.
Aims
To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.
Method
Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.
Results
Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.
Conclusions
AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses.
The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.
In contrast to temperate regions, relationships between basin characteristics (e.g., type/size) and fossil pollen archives have received little attention in Amazonia. Here, we compare fossil pollen records of a small palm swamp (Cuatro Vientos; CV) and a nearby large lake (Laguna Chaplin, LCH) in Bolivian Amazonia, demonstrating that palm swamps can yield Quaternary pollen archives recording the history of terrestrial vegetation beyond the basin margin, rather than merely a history of localized swamp vegetation dynamics. The pollen assemblages from these two contrasting basins display remarkable agreement throughout their late Quaternary history, indicating past drier climates supported savanna landscape during the last glacial maximum (LGM; 24,000–18,000 cal yr BP) and savanna/semideciduous forest mosaic during the middle Holocene (7000-4750 cal yr BP) at both regional (inferred from LCH) and local (inferred from CV) spatial scales. Additionally, the local-scale catchment of CV and the basin's proximity to the riverine forests of the Río Paraguá enables exploration of the extent of gallery/riverine forests during the LGM and middle Holocene. We show that, between 24,000–4000 cal yr BP, riverine/gallery rainforests were substantially reduced compared with present, challenging the hypothesis that gallery rainforests were important refugia for rainforest species during the drier LGM and middle Holocene.
A single radiocarbon date derived from the Buhl burial in south-central Idaho has frequently been used as a data point for the interpretation of the Western Stemmed Tradition (WST) chronology and technology because of the stemmed biface found in situ with the human remains. AMS dating of bone collagen in 1991 produced an age of 10,675 ± 95 14C BP, immediately postdating the most widely accepted age range for Clovis. The Buhl burial has been cited as evidence that stemmed point technology may have overlapped with Clovis technology in the Intermountain West. We discuss concerns about the radiocarbon date, arguing that even at face value, the calibrated date has minimal overlap with Clovis at the 95.4% range. Furthermore, the C:N ratio of 3.69 in the analyzed collagen is outside of the typical range for well-preserved samples, indicating a postdepositional change in carbon composition, which may make the date erroneously older or younger than the age of the skeleton. Finally, the potential dietary incorporation of small amounts of anadromous fish may indicate that the burial is younger than traditionally accepted. For these reasons, we argue that the Buhl burial cannot be used as evidence of overlap between WST and Clovis.
Adverse programming of adult non-communicable disease can be induced by poor maternal nutrition during pregnancy and the periconception period has been identified as a vulnerable period. In the current study, we used a mouse maternal low-protein diet fed either for the duration of pregnancy (LPD) or exclusively during the preimplantation period (Emb-LPD) with control nutrition provided thereafter and postnatally to investigate effects on fetal bone development and quality. This model has been shown previously to induce cardiometabolic and neurological disease phenotypes in offspring. Micro 3D computed tomography examination at fetal stages Embryonic day E14.5 and E17.4, reflecting early and late stages of bone formation, demonstrated LPD treatment caused increased bone formation of relative high mineral density quality in males, but not females, at E14.5, disproportionate to fetal growth, with bone quality maintained at E17.5. In contrast, Emb-LPD caused a late increase in male fetal bone growth, proportionate to fetal growth, at E17.5, affecting central and peripheral skeleton and of reduced mineral density quality relative to controls. These altered dynamics in bone growth coincide with increased placental efficiency indicating compensatory responses to dietary treatments. Overall, our data show fetal bone formation and mineral quality is dependent upon maternal nutritional protein content and is sex-specific. In particular, we find the duration and timing of poor maternal diet to be critical in the outcomes with periconceptional protein restriction leading to male offspring with increased bone growth but of poor mineral density, thereby susceptible to later disease risk.
Recent work suggests that antihypertensive medications may be useful as repurposed treatments for mood disorders. Using large-scale linked healthcare data we investigated whether certain classes of antihypertensive, such as angiotensin antagonists (AAs) and calcium channel blockers, were associated with reduced risk of new-onset major depressive disorder (MDD) or bipolar disorder (BD).
Method
Two cohorts of patients treated with antihypertensives were identified from Scottish prescribing (2009–2016) and hospital admission (1981–2016) records. Eligibility for cohort membership was determined by a receipt of a minimum of four prescriptions for antihypertensives within a 12-month window. One treatment cohort (n = 538 730) included patients with no previous history of mood disorder, whereas the other (n = 262 278) included those who did. Both cohorts were matched by age, sex and area deprivation to untreated comparators. Associations between antihypertensive treatment and new-onset MDD or bipolar episodes were investigated using Cox regression.
Results
For patients without a history of mood disorder, antihypertensives were associated with increased risk of new-onset MDD. For AA monotherapy, the hazard ratio (HR) for new-onset MDD was 1.17 (95% CI 1.04–1.31). Beta blockers' association was stronger (HR 2.68; 95% CI 2.45–2.92), possibly indicating pre-existing anxiety. Some classes of antihypertensive were associated with protection against BD, particularly AAs (HR 0.46; 95% CI 0.30–0.70). For patients with a past history of mood disorders, all classes of antihypertensives were associated with increased risk of future episodes of MDD.
Conclusions
There was no evidence that antihypertensive medications prevented new episodes of MDD but AAs may represent a novel treatment avenue for BD.
Determining infectious cross-transmission events in healthcare settings involves manual surveillance of case clusters by infection control personnel, followed by strain typing of clinical/environmental isolates suspected in said clusters. Recent advances in genomic sequencing and cloud computing now allow for the rapid molecular typing of infecting isolates.
Objective:
To facilitate rapid recognition of transmission clusters, we aimed to assess infection control surveillance using whole-genome sequencing (WGS) of microbial pathogens to identify cross-transmission events for epidemiologic review.
Methods:
Clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, and Klebsiella pneumoniae were obtained prospectively at an academic medical center, from September 1, 2016, to September 30, 2017. Isolate genomes were sequenced, followed by single-nucleotide variant analysis; a cloud-computing platform was used for whole-genome sequence analysis and cluster identification.
Results:
Most strains of the 4 studied pathogens were unrelated, and 34 potential transmission clusters were present. The characteristics of the potential clusters were complex and likely not identifiable by traditional surveillance alone. Notably, only 1 cluster had been suspected by routine manual surveillance.
Conclusions:
Our work supports the assertion that integration of genomic and clinical epidemiologic data can augment infection control surveillance for both the identification of cross-transmission events and the inclusion of missed and exclusion of misidentified outbreaks (ie, false alarms). The integration of clinical data is essential to prioritize suspect clusters for investigation, and for existing infections, a timely review of both the clinical and WGS results can hold promise to reduce HAIs. A richer understanding of cross-transmission events within healthcare settings will require the expansion of current surveillance approaches.
We identified a pseudo-outbreak of Mycobacterium avium in an outpatient bronchoscopy clinic following an increase in clinic procedure volume. We terminated the pseudo-outbreak by increasing the frequency of automated endoscope reprocessors (AER) filter changes from quarterly to monthly. Filter changing schedules should depend on use rather than fixed time intervals.
Second-mode wave growth within the hypersonic boundary layer of a slender cone is investigated experimentally using high-speed schlieren visualizations. Experiments were performed in AEDC Tunnel 9 over a range of unit Reynolds number conditions at a Mach number of approximately 14. A thin lens with a known density profile placed within the field of view enables calibration of the schlieren set-up, and the relatively high camera frame rates employed allow for the reconstruction of time-resolved pixel intensities at discrete streamwise locations. The calibration in conjunction with the reconstructed signals enables integrated spatial amplification rates ($N$ factors) to be calculated for each unit Reynolds number condition and compared to $N$ factors computed from both pressure transducer measurements and linear parabolized stability equation (PSE) solutions. Good agreement is observed between $N$ factors computed from the schlieren measurements and those computed from the PSE solutions for the most-amplified second-mode frequencies. The streamwise development of $N$ factors calculated from the schlieren measurements compares favourably to that calculated from the pressure measurements with slight variations in the $N$ factor magnitudes calculated for harmonic frequencies. Finally, a bispectral analysis is carried out to identify nonlinear phase-coupled quadratic interactions present within the boundary layer. Multiple interactions are identified and revealed to be associated with the growth of disturbances at higher harmonic frequencies.
New dating confirms that people occupied the Australian continent before the earliest time inferred from conventional radiocarbon analysis. Many of the new ages were obtained by accelerator mass spectrometry 14C dating after an acid–base–acid pretreatment with bulk combustion (ABA-BC) or after a newly developed acid–base–wet oxidation pretreatment with stepped combustion (ABOX-SC). The samples (charcoal) came from the earliest occupation levels of the Devil's Lair site in southwestern Western Australia. Initial occupation of this site was previously dated 35,000 14C yr B.P. Whereas the ABA-BC ages are indistinguishable from background beyond 42,000 14C yr B.P., the ABOX-SC ages are in stratigraphic order to ∼55,000 14C yr B.P. The ABOX-SC chronology suggests that people were in the area by 48,000 cal yr B.P. Optically stimulated luminescence (OSL), electron spin resonance (ESR) ages, U-series dating of flowstones, and 14C dating of emu eggshell carbonate are in agreement with the ABOX-SC 14C chronology. These results, based on four independent techniques, reinforce arguments for early colonization of the Australian continent.
Machine-vision cultivator guidance systems are commercially available to growers, but little work has been done to determine if these guidance systems can improve integrated weed management systems in vegetable crops. Studies were conducted in 2005 and 2006 in broccoli and lettuce to evaluate band-applied DCPA or pronamide, respectively, and four noncultivated bands ranging from 5.1 to 12.7 cm. DCPA or pronamide were applied in bands centered on the seed line at 0, 7.6 or 12.7 cm wide. A commercial machine-vision system was used to guide a commercial cultivator. Generally, weed densities and hand-weeding times were less where the DCPA band in broccoli or the pronamide band in lettuce were 7.6 or 12.7 cm wide compared to no herbicide. Weed densities were lowest in both crops where the noncultivated band width was 5.1 cm compared to 12.7-cm noncultivated bands. For broccoli in both 2005 and 2006, net returns above production costs were generally higher in the 7.6- and 12.7-cm-wide DCPA bands compared with the no-herbicide band. In lettuce in both years, the no-pronamide treatment had higher net returns, when compared with the 7.6- and 12.7-cm pronamide bands. Lettuce yields and higher net returns in the no-pronamide treatment compared to the 7.6- and 12.7-cm pronamide bands may be due to slight yield reduction from pronamide. Results suggest that pronamide was not needed during the dry months of the year when weed management tools such as hand-weeding and cultivation work very well. However, in periods of rainy weather when cultivation and hand-weeding are not possible, then pronamide would likely provide the greatest economic benefit. Given the large impact of cultivation on vegetable weed management programs, the greatest potential benefit of machine-vision guided cultivators is if they facilitate more timely and effective cultivation.
Few herbicides are available for use in lettuce and hand weeding is required for commercially acceptable weed control. More effective herbicides are needed. Here field evaluations of pendimethalin and S-metolachlor for weed control in transplanted lettuce are reported. Pendimethalin was evaluated PRE at rates between 0.6 and 6.7 kg ai ha−1, and POST at 1.1 and 2.2 kg ha−1. Both pendimethalin PRE and POST applications were safe to transplanted lettuce and provided similar weed control. Pendimethalin PRE at rates of 1.1 kg ha−1 and higher provided better weed control than the industry standard, pronamide at 1.3 kg ha−1. S-Metolachlor PRE was evaluated at rates between 0.6 and 5.6 kg ha−1. S-Metolachlor at rates up to 2.8 kg ha−1 caused little or no crop injury or yield reduction in transplanted lettuce, and S-metolachlor at rates of 1.4 kg ha−1 and higher improved weed control compared with pronamide at 1.3 kg ha−1. Pendimethalin and S-metolachlor are not labeled for transplanted lettuce, but we suggest that labeling be pursued at rates of 1.1 and 0.7 kg ha−1, respectively. Pendimethalin at 1.1 kg ha−1 applied PRE or POST improved weed control by 57 and 42%, respectively compared with pronamide. S-Metolachlor PRE at 0.7 kg ha−1 was less effective on weeds than pendimethalin, but maintained weed control level similar to pronamide. Pendimethalin and S-metolachlor have potential for use in transplanted lettuce production and provide alternatives to current transplanted lettuce herbicides.
Weed science has contributed much to agriculture, forestry and natural resource management during its history. However, if it is to remain relevant as a scientific discipline, it is long past time for weed scientists to move beyond a dominating focus on herbicide efficacy testing and address the basic science underlying complex issues in vegetation management at many levels of biological organization currently being solved by others, such as invasion ecologists and molecular biologists. Weed science must not be circumscribed by a narrowly-defined set of tools but rather be seen as an integrating discipline. As a means of assessing current and future research interests and funding trends among weed scientists, the Weed Science Society of America conducted an online survey of its members in summer of 2007. There were 304 respondents out of a membership of 1330 at the time of the survey, a response rate of 23%. The largest group of respondents (41%) reported working on research problems primarily focused on herbicide efficacy and maintenance, funded mainly by private industry sources. Another smaller group of respondents (22%) reported focusing on research topics with a complex systems focus (such as invasion biology, ecosystem restoration, ecological weed management, and the genetics, molecular biology, and physiology of weedy traits), funded primarily by public sources. Increased cooperation between these complementary groups of scientists will be an essential step in making weed science increasingly relevant to the complex vegetation management issues of the 21st century.
Agroecosystems are inherently complex, and practices aimed at managing one component of the system can have unintended consequences for other components of the system. Management decisions, therefore, can be improved by assessing and understanding the multivariate nature of agricultural systems and the multifunctional character of particular agricultural management practices. The act of simultaneously assessing and evaluating multiple characteristics or functions in agriculture also can be a valuable education and extension activity, because it draws on active and experiential methods of learning and because the process effectively reveals important functions and tradeoffs associated with agroecosystems and their management. Here we introduce a tool (the spider plot) and present a case-study exercise in which we used this tool to evaluate the multiple characteristics and functions of different cover crops within a field day workshop format. We also provide examples of how this approach could be used to assess other management practices or properties of agroecosystems and communicate multivariate concepts within a weed science classroom or extension environment.