To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
A new fossil site in a previously unexplored part of western Madagascar (the Beanka Protected Area) has yielded remains of many recently extinct vertebrates, including giant lemurs (Babakotia radofilai, Palaeopropithecus kelyus, Pachylemur sp., and Archaeolemur edwardsi), carnivores (Cryptoprocta spelea), the aardvark-like Plesiorycteropus sp., and giant ground cuckoos (Coua). Many of these represent considerable range extensions. Extant species that were extirpated from the region (e.g., Prolemur simus) are also present. Calibrated radiocarbon ages for 10 bones from extinct primates span the last three millennia. The largely undisturbed taphonomy of bone deposits supports the interpretation that many specimens fell in from a rock ledge above the entrance. Some primates and other mammals may have been prey items of avian predators, but human predation is also evident. Strontium isotope ratios (87Sr/86Sr) suggest that fossils were local to the area. Pottery sherds and bones of extinct and extant vertebrates with cut and chop marks indicate human activity in previous centuries. Scarcity of charcoal and human artifacts suggests only occasional visitation to the site by humans. The fossil assemblage from this site is unusual in that, while it contains many sloth lemurs, it lacks ratites, hippopotami, and crocodiles typical of nearly all other Holocene subfossil sites on Madagascar.
Application timing and environmental factors reportedly influence the efficacy of auxinic herbicides. In resistance-prone weed species such as Palmer amaranth (Amaranthus palmeri S. Watson), efficacy of auxinic herbicides recently adopted for use in resistant crops is of utmost importance to reduce selection pressure for herbicide resistance traits. Growth chamber experiments were conducted comparing the interaction of different environmental effects with application time to determine the influence of these factors on visible phytotoxicity and hydrogen peroxide (H2O2) formation in Amaranthus palmeri. Temperature displayed a high degree of influence on 2,4-D and dicamba efficacy in general, with applications at the low temperature treatment (31/20°C day/night) resulting in an increase in phytotoxicity, respectively, compared to high temperature treatments (41/30°C day/night). Application time across temperature treatments significantly affected 2,4-D-induced phytotoxicity, resulting in a ≥ 30% increase across rates with treatments at 4:00 pm compared to 8:00 am. Temperature differential had a significant influence on dicamba efficacy based on visible phytotoxicity data, with a ≥ 46% increase with high (37/20°C day/night) compared to low differential (41/30°C day/night). Concentration of H2O2 in herbicide treated plants was 34% higher under a high temperature differential compared to the low differential. Humidity treatments and application time interactions displayed undetected or inconsistent effects on visible phytotoxicity and H2O2 production. Overall, temperature-related influences seem to hold the largest environmental effect on auxinic herbicides within conditions evaluated in this study. Leaf concentration of H2O2 appears to be generally correlated with phytotoxicity, providing a potentially useful tool in determining efficacy of auxinic herbicides in field settings.
Pelvic internal organs change in volume and position during radiotherapy. This may compromise the efficacy of treatment or worsen its toxicity. There may be limitations to fully correcting these changes using online image guidance; therefore, effective and consistent patient preparation and positioning remain important. This review aims to provide an overview of the extent of pelvic organ motion and strategies to manage this motion.
Methods and Materials:
Given the breadth of this topic, a systematic review was not undertaken. Instead, existing systematic reviews and individual high-quality studies addressing strategies to manage pelvic organ motion have been discussed. Suggested levels of evidence and grades of recommendation for each strategy have been applied.
Various strategies to manage rectal changes have been investigated including diet and laxatives, enemas and rectal emptying tubes and rectal displacement with endorectal balloons (ERBs) and rectal spacers. Bladder-filling protocols and bladder ultrasound have been used to try to standardise bladder volume. Positioning the patient supine, using a full bladder and positioning prone with or without a belly board, has been examined in an attempt to reduce the volume of irradiated small bowel. Some randomised trials have been performed, with evidence to support the use of ERBs, rectal spacers, bladder-filling protocols and the supine over prone position in prostate radiotherapy. However, there was a lack of consistent high-quality evidence that would be applicable to different disease sites within the pelvis. Many studies included small numbers of patients were non-randomised, used less conformal radiotherapy techniques or did not report clinical outcomes such as toxicity.
There is uncertainty as to the clinical benefit of many of the commonly adopted interventions to minimise pelvic organ motion. Given this and the limitations in online image guidance compensation, further investigation of adaptive radiotherapy strategies is required.
In March 2017, the New Jersey Department of Health received reports of 3 patients who developed septic arthritis after receiving intra-articular injections for osteoarthritis knee pain at the same private outpatient facility in New Jersey. The risk of septic arthritis resulting from intra-articular injection is low. However, outbreaks of septic arthritis associated with unsafe injection practices in outpatient settings have been reported.
An infection prevention assessment of the implicated facility’s practices was conducted because of the ongoing risk to public health. The assessment included an environmental inspection of the facility, staff interviews, infection prevention practice observations, and a medical record and office document review. A call for cases was disseminated to healthcare providers in New Jersey to identify patients treated at the facility who developed septic arthritis after receiving intra-articular injections.
We identified 41 patients with septic arthritis associated with intra-articular injections. Cultures of synovial fluid or tissue from 15 of these 41 case patients (37%) recovered bacteria consistent with oral flora. The infection prevention assessment of facility practices identified multiple breaches of recommended infection prevention practices, including inadequate hand hygiene, unsafe injection practices, and poor cleaning and disinfection practices. No additional cases were identified after infection prevention recommendations were implemented by the facility.
Aseptic technique is imperative when handling, preparing, and administering injectable medications to prevent microbial contamination.
This investigation highlights the importance of adhering to infection prevention recommendations. All healthcare personnel who prepare, handle, and administer injectable medications should be trained in infection prevention and safe injection practices.
Research was conducted from 2013 to 2015 across three sites in Mississippi to evaluate corn response to sublethal paraquat or fomesafen (105 and 35 g ai ha−1, respectively) applied PRE, or to corn at the V1, V3, V5, V7, or V9 growth stages. Fomesafen injury to corn at three d after treatment (DAT) ranged from 0% to 38%, and declined over time. Compared with the nontreated control (NTC), corn height 14 DAT was reduced approximately 15% due to fomesafen exposure at V5 or V7. Exposure at V1 or V7 resulted in 1,220 and 1,110 kg ha−1 yield losses, respectively, compared with the NTC, but yield losses were not observed at any other growth stage. Fomesafen exposure at any growth stage did not affect corn ear length or number of kernel rows relative to the NTC. Paraquat injury to corn ranged from 26% to 65%, depending on growth stage and evaluation interval. Corn exposure to paraquat at V3 or V5 consistently caused greater injury across evaluation intervals, compared with other growth stages. POST timings of paraquat exposure resulted in corn height reductions of 13% to 50%, except at V7, which was most likely due to rapid internode elongation at that stage. Likewise, yield loss occurred after all exposure times of paraquat except PRE, compared with the NTC. Corn yield was reduced 1,740 to 5,120 kg ha−1 compared with the NTC, generally worsening as exposure time was delayed. Paraquat exposure did not reduce corn ear length, compared with the NTC, at any growth stage. However, paraquat exposure at V3 or V5 was associated with reduction of kernel rows by 1.1 and 1.7, respectively, relative to the NTC. Paraquat and fomesafen applications near corn should be avoided if conditions are conducive for off-target movement, because significant injury and yield loss can result.
Hypoalbuminemia is associated with morbidity and mortality in critically ill children. In this multi-centre retrospective study, we aimed to determine normative values of serum albumin in neonates and infants with congenital heart disease, evaluate perioperative changes in albumin levels, and determine if low serum albumin influences post-operative outcomes. Consecutive eligible neonates and infants who underwent cardiac surgery with cardiopulmonary bypass at one of three medical centres, January 2012–August 2013, were included. Data on serum albumin levels from five data points (pre-operative, 0–24, 24–48, 48–72, 72 hours post-operative) were collected. Median pre-operative serum albumin level was 2.5 g/dl (IQR, 2.1–2.8) in neonates versus 4 g/dl (IQR, 3.5–4.4) in infants. Hypoalbuminemia was defined as <25th percentile of these values. A total of 203 patients (126 neonates, 77 infants) were included in the study. Post-operative hypoalbuminemia developed in 12% of neonates and 20% of infants; 97% occurred in the first 48 hours. In multivariable analysis, perioperative hypoalbuminemia was not independently associated with any post-operative morbidity. However, when analysed as a continuous variable, lower serum albumin levels were associated with increased post-operative morbidity. Pre-operative low serum albumin level was independently associated with increased odds of post-operative hypoalbuminemia (OR, 3.67; 95% CI, 1.01–13.29) and prolonged length of hospital stay (RR, 1.40; 95% CI, 1.08–1.82). Lower 0–24-hour post-operative serum albumin level was independently associated with an increased duration of mechanical ventilation (RR, 1.35; 95% CI, 1.12–1.64). Future studies should further assess hypoalbuminemia in this population, with emphasis on evaluating clinically meaningful cut-offs and possibly the use of serum albumin levels in perioperative risk stratification models.
Childhood maltreatment (CM) plays an important role in the development of major depressive disorder (MDD). The aim of this study was to examine whether CM severity and type are associated with MDD-related brain alterations, and how they interact with sex and age.
Within the ENIGMA-MDD network, severity and subtypes of CM using the Childhood Trauma Questionnaire were assessed and structural magnetic resonance imaging data from patients with MDD and healthy controls were analyzed in a mega-analysis comprising a total of 3872 participants aged between 13 and 89 years. Cortical thickness and surface area were extracted at each site using FreeSurfer.
CM severity was associated with reduced cortical thickness in the banks of the superior temporal sulcus and supramarginal gyrus as well as with reduced surface area of the middle temporal lobe. Participants reporting both childhood neglect and abuse had a lower cortical thickness in the inferior parietal lobe, middle temporal lobe, and precuneus compared to participants not exposed to CM. In males only, regardless of diagnosis, CM severity was associated with higher cortical thickness of the rostral anterior cingulate cortex. Finally, a significant interaction between CM and age in predicting thickness was seen across several prefrontal, temporal, and temporo-parietal regions.
Severity and type of CM may impact cortical thickness and surface area. Importantly, CM may influence age-dependent brain maturation, particularly in regions related to the default mode network, perception, and theory of mind.
The statistical distributions of main-sequence multiple-star properties reveal invaluable insights into the processes of binary star formation, and they provide initial conditions for population synthesis studies of binary star evolution. Binary stars are discovered and characterised through a variety of techniques. Correcting for their respective selection effects and combining the bias-corrected results is not a trivial process. This is partially because the intrinsic distributions of companion frequency, primary mass M1, orbital period P, mass ratio q and eccentricity e are all interrelated , i.e., f(M1,P,q,e)/= f(M1)f(P)f(q)f(e). In particular, the binary fraction increases with primary mass, especially across short orbital periods, and binaries become weighted towards larger eccentricities and more extreme mass ratios with increasing separation, especially for more massive primaries. Moreover, binary star statistics vary with age, environment and metallicity. This chapter summarises the strengths and limitations of the various observational techniques, and reviews the statistical correlations in the intrinsic (bias-corrected) multiple-star properties.
With the discovery of both binary black hole mergers and a binary neutron star merger, the field of gravitational wave astrophysics has really begun. The LIGO and Virgo detectors will soon improve their sensitivity allowing for the detection of thousands new sources. All these measurements will provide new answers to open questions in binary evolution related to mass transfer, out-of-equilibrium stars and the role of metallicity. The data will give new constraints on uncertainties in the evolution of (massive) stars, such as stellar winds, the role of rotation and the final collapse to a neutron star or black hole. In the long run, the thousands of detections by the Einstein Telescope will enable us to probe their population in great detail over the history of the Universe. For neutron stars, the first question is whether the first detection GW170817 is a typical source or not. In any case, it has spectacularly shown the promise of complementary electromagnetic follow-up. For white dwarfs, we have to wait for LISA (around 2034), but new detections by, e.g., Gaia and LSST will prepare for the astrophysical exploitation of the LISA measurements.
Binary stars are of course more than two stars, but they are also at least two stars. This chapter will review some aspects of the physics governing the evolution of single massive stars. It will also review the uncertainties of key physical ingredients: mass loss, rotation and convection.
Any white dwarf or neutron star that accretes enough material from a red giant companion, such that this interaction can be detected at some wavelength, is currently termed a symbiotic star (orbital period ∼2–3 years). In the majority of ∼400 known systems, the white dwarf burns nuclearly at its surface the accreted material, and the resulting high temperature and luminosity allow ionisation of a large fraction of the cool giant’s wind. X-ray observations are revealing the existence of a parallel (and large ?) population of optically quiet, accreting-only symbiotic stars. Accretion flows and disks, ionisation fronts and shock, complex 3D geometries and new evolution channels are gaining relevance and are reshaping our understanding of symbiotic stars. The chapter reviews the different types of symbiotic stars currently in the family and their variegated outburst behaviours.
Many aspects of the evolution of stars, and in particular the evolution of binary stars, are beyond our ability to model them in detail. Instead, we rely on observations to guide our often phenomenological models and pin down uncertain model parameters. To do this statistically requires population synthesis. Populations of stars modelled on computers are compared to populations of stars observed with our best telescopes. The closest match between observations and models provides insight into unknown model parameters and hence the underlying astrophysics. This chapter reviews the impact that modern big-data surveys will have on population synthesis, the large parameter space problem that is rife for the application of modern data science algorithms and some examples of how population synthesis is relevant to modern astrophysics.
We still do not have an end-to-end theory of binary star formation that both satisfies observational constraints and also includes all necessary physical ingredients. Large-scale star formation simulations do an excellent job of replicating binary statistics under severely simplified physical conditions (neglect of thermal feedback and magnetic fields). Simulations that include these processes, however, tend to suppress binary formation, and their extra computational expense makes it hard to generate statistical samples of binaries for observational comparison. In addition to reviewing the literature on binary formation simulations, this chapter also examines the insights into the process that are provided by observations of the youngest protomultiple systems.
Short-duration gamma-ray bursts (short-GRBs) are thought to be produced during the merger of compact binary stars involving at least one neutron star. The recent detection of a gravitational wave signal coincident with a short-GRB (170817), albeit one with unusually low intrinsic luminosity, has cemented this link and opened a new era of multimessenger astrophysics. Long-duration gamma-ray bursts are produced by the core collapse of envelope-stripped massive stars, which may also be the end product of binary evolution. Establishing the nature of the long-GRB progenitor more definitely is important not only for our understanding of GRBs, but also for their use as probes of the distant Universe, many of which depend on how representative GRBs are of the general population of massive stars.