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.
In this study, we use aerial photographs, satellite imagery and field observations to quantify changes in the area, terminus length, snowline elevation and surface elevation of eight glaciers in the Alexandra Fiord region, eastern Ellesmere Island, between 1959 and 2019. Comparisons to written and pictorial descriptions from the British Arctic Expedition extend the record of change in terminus position and surface elevation to 1875 for Twin Glacier. Glacier area at Alexandra Fiord decreased by a total of 15.77 ± 0.65 km2 (11.77 ± 0.49%) between 1959 and 2019, the mean end of summer snowline increased in elevation by 360 ± 84 m (8 ± 2 m a−1) between 1974 and 2019, and the glaciers thinned at an average rate of 0.60 ± 0.06 m a−1 between 2001 and 2018. Annual rates of terminus retreat were ~3–5 times higher over the period 1974–2019 compared to 1875–1974, and rates of thinning were ~2–3 times higher over 2001–18 compared to 1875–2001. Our results are consistent with rates of change determined for other glaciers of similar size on Ellesmere Island, and with accelerated rates of ice loss coincident with regional increases in air temperature of ~1.5°C since the early 1980s.
This study examined a potential lexicality advantage in young children's early speech production: do children produce sound sequences less accurately in nonwords than real words? Children aged 3;3-4;4 completed two tasks: a real word repetition task and a corresponding nonword repetition task. Each of the 23 real words had a paired consonant-vowel sequence in the nonword in word-initial position (e.g., ‘su’ in [ˈsutkes] ‘suitcase’ and [ˈsudrɑs]). The word-initial consonant-vowel sequences were kept constant between the paired words. Previous work on this topic compared different sequences of paired sounds, making it hard to determine if those results were due to a lexical or phonetic effect. Our results show that children reliably produced consonant-vowel sequences in real words more accurately than nonwords. The effect was most pronounced in children with smaller receptive vocabularies. Together, these results reinforce theories arguing for interactions between vocabulary size and phonology in language development.
Surgical site infections (SSIs) are among the most common healthcare-associated infections in low- and middle-income countries. To encourage establishment of actionable and standardized SSI surveillance in these countries, we propose simplified surveillance case definitions. Here, we use NHSN reports to explore concordance of these simplified definitions to NHSN as ‘reference standard.’
This study investigated whether individual differences in receptive vocabulary, speech perception and production, and nonword repetition at age 2 years, 4 months to 3 years, 4 months predicted phonological awareness 2 years later. One hundred twenty-one children were tested twice. During the first testing period (Time 1), children’s receptive vocabulary, speech perception and production, and nonword repetition were measured. Nonword repetition accuracy in the present study was distinct from other widely used measures of nonword repetition in that it focused on narrow transcription of diphone sequences in each nonword that differed systematically in phonotactic probability. At the second testing period (Time 2), children’s phonological awareness was measured. The best predictors of phonological awareness were a measure of speech production and a measure of phonological processing derived from performance on the nonword repetition task. The results of this study suggest that nonword repetition accuracy provides an implicit measure of phonological skills that are indicative of later phonological awareness at an age when children are too young to perform explicit phonological awareness tasks reliably.
The duodenum lies in front of the right kidney and renal vessels, the right psoas muscle, the inferior vena cava, and the aorta (Figure 26.1).
The duodenum is approximately 25 cm in length. It is the most fixed part of the small intestine and has no mesentery. It is anatomically divided into four parts:
The superior or first portion is intraperitoneal along the anterior half of its circumference. Superiorly, the first portion is attached to the hepatoduodenal ligament. The posterior wall is associated with the gastroduodenal artery, common bile duct, and the portal vein.
The descending or second portion shares a medial border with the head of the pancreas. It is bordered posteriorly by the medial surface of the right kidney, the right renal vessels, and the inferior vena cava. The hepatic flexure and transverse colon cross anteriorly. The common bile duct and main pancreatic duct drain into the medial wall of the descending duodenum.
The transverse or third portion is also entirely retroperitoneal. Posteriorly, it is bordered by the inferior vena cava and the aorta. The superior mesenteric vessels cross in front of this portion of the duodenum.
The ascending or fourth portion of the duodenum is approximately 2.5 cm in length and is primarily retroperitoneal, except for the most distal segment. It crosses anterior to and ascends to the left of the aorta to join the jejunum at the ligament of Treitz.
The common bile duct courses laterally within the hepatodudenal ligament and lies posterior to the first portion of the duodenum and pancreatic head, becoming partially invested within the parenchyma of the pancreatic head. The main pancreatic duct then joins the common bile duct to drain into the ampulla of Vater within the second portion of the duodenum. The ampulla of Vater is located approximately 7 cm from the pylorus. The accessory pancreatic duct drains approximately 2 cm proximal to the ampulla of Vater.
The vascular supply to the duodenum is intimately associated with the head of the pancreas. The head of the pancreas and the second portion of the duodenum derive their blood supply from the anterior and posterior pancreaticoduodenal arcades (Figure 26.2). These arcades lie on the surface of the pancreas near the duodenal C loop. Attempts to separate these two organs at this location usually results in ischemia of the duodenum.
Statistical models are commonly employed in the estimation of influenza-associated excess mortality that, due to various reasons, is often underestimated by laboratory-confirmed influenza deaths reported by healthcare facilities. However, methodology for timely and reliable estimation of that impact remains limited because of the delay in mortality data reporting. We explored real-time estimation of influenza-associated excess mortality by types/subtypes in each year between 2012 and 2018 in Hong Kong using linear regression models fitted to historical mortality and influenza surveillance data. We could predict that during the winter of 2017/2018, there were ~634 (95% confidence interval (CI): (190, 1033)) influenza-associated excess all-cause deaths in Hong Kong in population ⩾18 years, compared to 259 reported laboratory-confirmed deaths. We estimated that influenza was associated with substantial excess deaths in older adults, suggesting the implementation of control measures, such as administration of antivirals and vaccination, in that age group. The approach that we developed appears to provide robust real-time estimates of the impact of influenza circulation and complement surveillance data on laboratory-confirmed deaths. These results improve our understanding of the impact of influenza epidemics and provide a practical approach for a timely estimation of the mortality burden of influenza circulation during an ongoing epidemic.
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.
Hoerl & McCormack propose that animals learn sequences through an entrainment-like process, rather than tracking the temporal addresses of each event in a given sequence. However, past research suggests that animals form “temporal maps” of sequential events and also comprehend the concept of ordinal position. These findings suggest that a clarification or qualification of the authors’ hypothesis is needed.
The Middle Bronze Age (c. 1600–1150 cal bc) in Britain is traditionally understood to represent a major funerary transition. This is a transformation from a heterogeneous funerary rite, largely encompassing inhumations and cremations in burial mounds and often accompanied by grave goods, to a homogeneous and unadorned cremation-based practice. Despite a huge expansion in the number of well excavated, radiocarbon dated, and osteologically analysed sites in the last three decades, current interpretations of Middle Bronze Age cremation burials still rely upon a seminal paper by Ellison (1980), which proposed that they comprise and represent an entire community. This paper analyses 378 cremation sites containing at least 3133 burials which represent all those that can be confidently dated to the Middle Bronze Age in Britain. The new analysis demonstrates that relatively few sites can be characterised as community cemeteries and that there are substantially more contemporary settlement sites, though few contemporary settlements are in close proximity to the cemeteries. The identifiable characteristics of cremation-based funerary practices are consistent across Britain with little evidence for social differentiation at the point of burial. It is also evident that only a minority of the population received a cremation burial. There is a substantial decrease in archaeologically visible funerary activity from the preceding Early Bronze Age (c. 2200–1600 cal bc) and a further decrease in the proceeding Late Bronze Age (c. 1150–800 cal bc) in Britain. This is comparable in form, and partially in sequence, to Bronze Age funerary practices in Ireland and several regions in North-west Europe.
Glyphosate-resistant (GR) Italian ryegrass is one of the most troublesome weeds in Mississippi row crop production. Fall-applied residual herbicide applications are recommended for control of GR Italian ryegrass. However, carryover of residual herbicides applied in fields for rice production can have a negative impact on rice performance. Field studies were conducted in Stoneville, MS, to determine the effects of fall-applied residual herbicides on rice growth and yield. Herbicide treatments included suggested use rates (1×) of clomazone at 840 g ai ha–1, pyroxasulfone 170 g ai ha–1, S-metolachlor 1,420 g ai ha–1, and trifluralin 1,680 g ai ha–1, and two times (2×) the suggested use rates in the fall before rice seeding. Pooled across application rate, pyroxasulfone, S-metolachlor, and trifluralin injured rice to an extent 28% to 36% greater than clomazone 14 d after emergence (DAE). Rice seedling density and height 14 DAE and rice maturity were negatively affected by all fall-applied herbicides except clomazone. Applications at 2× rates reduced rough rice yields in plots treated with pyroxasulfone, S-metolachlor, and trifluralin compared with clomazone. Pyroxasulfone applied at the 2× rate reduced rough rice yield 22% compared with the 1× rate. Rough rice yield was 90% or greater of the nontreated control in plots treated with either rate of S-metolachlor, and these were comparable with rough rice yields from plots treated with both rates of trifluralin and the 1× rate of pyroxasulfone. Early-season injury and reductions in seedling density and height 14 DAE, would preclude even 1× applications of pyroxasulfone, S-metolachlor, and trifluralin from being viable options for residual herbicide treatments targeting GR Italian ryegrass in the fall before rice seeding. Of the herbicides evaluated, only clomazone should be utilized as a fall-applied residual herbicide treatment targeting GR Italian ryegrass before seeding rice.
The building blocks of planets in planet-forming (“protoplanetary”) disks are assembled early in the lifetime of a young star. The gas disks are relatively short-lived, with a half-life of about 3 million years, as chemical reactions modify the reservoir of material from the natal molecular cloud. Spitzer Space Telescope Infrared Spectrograph (IRS) spectra of protoplanetary disks around T Tauri stars show emission from H2O and absorption from other gases, sometimes consistent with formaldehyde, H2CO , and other times consistent with formic acid, HCOOH, in the 5-7.5 μm region. SOFIA-EXES spectra of YSOs that follow up on these Spitzer-IRS studies are presented. How the gaseous features observed between 5-7.5 μm relate to those at other wavelengths is discussed. This work suggests that water and organic molecules, which are crucial for life as we know it, are present in the habitable zones of stars at a very early age [of 1-3 million years].
Accurate quantification of rates of glacier mass loss is critical for managing water resources and for assessing hazards at ice-clad volcanoes, especially in arid regions like southern Peru. In these regions, glacier and snow melt are crucial dry season water resources. In order to verify previously reported rates of ice area decline at Nevado Coropuna in Peru, which are anomalously rapid for tropical glaciers, we measured changes in ice cap area using 259 Landsat images acquired from 1980 to 2014. We find that Coropuna Ice Cap is presently the most extensive ice mass in the tropics, with an area of 44.1 km2, and has been shrinking at an average area loss rate of 0.409 km2 a−1 (~0.71% a−1) since 1980. Our estimated rate of change is considerably lower than previous studies (1.4 km2 a−1 or ~2.43% a−1), but is consistent with other tropical regions, such as the Cordillera Blanca located ~850 km to the NW (~0.68% a−1). Thus, if glacier recession continues at its present rate, our results suggest that Coropuna Ice Cap will likely continue to contribute to water supply for agricultural and domestic uses until ~2120, which is nearly 100 years longer than previously predicted.
Major efforts are being undertaken to quantify seismic hazard and risk due to production-induced earthquakes in the Groningen gas field as the basis for rational decision-making about mitigation measures. An essential element is a model to estimate surface ground motions expected at any location for each earthquake originating within the gas reservoir. Taking advantage of the excellent geological and geophysical characterisation of the field and a growing database of ground-motion recordings, models have been developed for predicting response spectral accelerations, peak ground velocity and ground-motion durations for a wide range of magnitudes. The models reflect the unique source and travel path characteristics of the Groningen earthquakes, and account for the inevitable uncertainty in extrapolating from the small observed magnitudes to potential larger events. The predictions of ground-motion amplitudes include the effects of nonlinear site response of the relatively soft near-surface deposits throughout the field.
Population-based registries report 95% 5-year survival for children undergoing surgery for CHD. This study investigated paediatric cardiac surgical outcomes in the Australian indigenous population.
All children who underwent cardiac surgery between May, 2008 and August, 2014 were studied. Demographic information including socio-economic status, diagnoses and co-morbidities, and treatment and outcome data were collected at time of surgery and at last follow-up.
A total of 1528 children with a mean age 3.4±4.6 years were studied. Among them, 123 (8.1%) children were identified as indigenous, and 52.7% (62) of indigenous patients were in the lowest third of the socio-economic index compared with 28.2% (456) of non-indigenous patients (p⩽0.001). The indigenous sample had a significantly higher Comprehensive Aristotle Complexity score (indigenous 9.4±4.2 versus non-indigenous 8.7±3.9, p=0.04). The probability of having long-term follow-up did not differ between groups (indigenous 93.8% versus non-indigenous 95.6%, p=0.17). No difference was noted in 30-day mortality (indigenous 3.2% versus non-indigenous 1.4%, p=0.13). The 6-year survival for the entire cohort was 95.9%. The Cox survival analysis demonstrated higher 6-year mortality in the indigenous group – indigenous 8.1% versus non-indigenous 5.0%; hazard ratio (HR)=2.1; 95% confidence intervals (CI): 1.1, 4.2; p=0.03. Freedom from surgical re-intervention was 79%, and was not significantly associated with the indigenous status (HR=1.4; 95% CI: 0.9, 1.9; p=0.11). When long-term survival was adjusted for the Comprehensive Aristotle Complexity score, no difference in outcomes between the populations was demonstrated (HR=1.6; 95% CI: 0.8, 3.2; p=0.19).
The indigenous population experienced higher late mortality. This apparent relationship is explained by increased patient complexity, which may reflect negative social and environmental factors.
Cultivar and/or application of early-season (starter) nitrogen (N) fertilizer may influence rice tolerance to clomazone. Field studies were conducted to compare the response of hybrid and inbred rice cultivars to applications of clomazone and starter N fertilizer treatments. The inbred cultivar ‘Cocodrie’ and the hybrid cultivar ‘XL723’ were treated with clomazone at 0, 420, or 672 g ai ha−1 immediately after seeding, and starter N fertilizer was applied at 0 or 24 kg N ha−1 when rice reached the two-leaf growth stage. Pooled across clomazone rates and starter N fertilizer treatments, height of Cocodrie 1 week after emergence (WAE) was greater than that of XL723 in 1 of 3 yr. The difference in height between Cocodrie and XL723 resulted from greater clomazone injury 1 WAE on XL723 compared with Cocodrie. No differences in rice height 3 WAE were detected between Cocodrie and XL723 in 2 of 3 yr. when data were pooled across clomazone rates and starter N fertilizer treatments. Injury 3 WAE was similar for Cocodrie across the 3 yr., but injury on XL723 was greater in 1 of 3 yr. Rough rice yield was lower in plots treated with either rate of clomazone where no starter N fertilizer treatment was applied; however, in plots receiving a starter N fertilizer treatment, no effect of clomazone rate on rough rice yield was observed. Clomazone rate did not influence rough rice yield of Cocodrie in any single yr., but rough rice yields of XL723 were lower in plots receiving clomazone compared with plots that received no clomazone in 1 of 3 yr. Therefore, differential susceptibility to clomazone between Cocodrie and XL723 exists based on early-season response and rough rice yield. Starter N fertilizer treatments were beneficial for overcoming yield reductions due to clomazone injury.
Measurements of the mechanical properties of snow are essential for improving our understanding and the prediction of snow failure and hence avalanche release. We performed fracture mechanical experiments in which a crack was initiated by a saw in a weak snow layer underlying cohesive snow slab layers. Using particle tracking velocimetry (PTV), the displacement field of the slab was determined and used to derive the mechanical energy of the system as a function of crack length. By fitting the estimates of mechanical energy to an analytical expression, we determined the slab effective elastic modulus and weak layer specific fracture energy for 80 different snowpack combinations, including persistent and nonpersistent weak snow layers. The effective elastic modulus of the slab ranged from 0.08 to 34 MPa and increased with mean slab density following a power-law relationship. The weak layer specific fracture energy ranged from 0.08 to 2.7 J m−2 and increased with overburden. While the values obtained for the effective elastic modulus of the slab agree with previously published low-frequency laboratory measurements over the entire density range, the values of the weak layer specific fracture energy are in some cases unrealistically high as they exceeded those of ice. We attribute this discrepancy to the fact that our linear elastic approach does not account for energy dissipation due to non-linear parts of the deformation in the slab and/or weak layer, which would undoubtedly decrease the amount of strain energy available for crack propagation.