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Nosocomial outbreaks due to multidrug-resistant microorganisms in rehabilitation centers have rarely been reported. We report an outbreak of extended-spectrum beta-lactamase (ESBL)–producing Klebsiella pneumoniae (ESBL-K. pneumoniae) on a single ward in a rehabilitation center in Rotterdam, The Netherlands.
A 40-bed ward of a rehabilitation center in the Netherlands.
In October 2016, 2 patients were found to be colonized by genetically indistinguishable ESBL-K. pneumoniae isolates. Therefore, an outbreak management team was installed, by whom a contact tracing plan was made. In addition to general outbreak measures, specific measures were formulated to allow continuation of the rehabilitation process. Also, environmental cultures were taken. Multiple-locus variable-number tandem-repeat analysis and amplification fragment-length polymorphism were used to determine strain relatedness. Selected isolates were subjected to whole-genome multilocus sequence typing.
The outbreak lasted 8 weeks. In total, 14 patients were colonized with an ESBL-K. pneumoniae, of whom 11 patients had an isolate belonging to sequence type 307. Overall, 163 environmental cultures were taken. Several sites of a household washing machine were repeatedly found to be contaminated with the outbreak strain. This machine was used to wash lifting slings and patient clothing contaminated with feces. The outbreak was contained after taking the machine temporarily out of service and implementing a reinforced and adapted protocol on the use of this machine.
We conclude that in this outbreak, the route of transmission of the outbreak strain via the household washing machine played a major role.
The ice-cored Galena Creek Rock Glacier, Wyoming, USA, has been the subject of a number of studies that sought to determine the origin of its ice. We present new observations of the rock glacier's internal structure from ground-penetrating radar to constrain ice and debris distribution and accumulation. We imaged dipping reflectors in the center of the glacier that are weak and discontinuous, in contrast to strong reflectors toward the edge of the cirque beneath large debris-avalanche chutes. These reflectors form a network of concave-up, up-glacier dipping layers. We interpret these as englacial debris bands formed by large debris falls buried by subsequent ice and snow accumulation. They are discontinuous where ice outpaces debris accumulation, but with sufficient debris accumulation an interleaved pattern of ice and debris layers can form. We propose a model in which the ice in these interleaved layers is snowfall preserved by debris-facilitated accumulation. Large debris falls that occur in early spring bury sections of the snowpack, which are then preserved through summer and incorporated into the rock glacier body over time. This study highlights the importance of sequential accumulation of ice and debris for understanding the dynamics of rock glaciers and debris-covered glaciers.
Effective treatment of maternal antenatal depression may ameliorate adverse neurodevelopmental outcomes in offspring. We performed two follow-up rounds of children at age 2 and age 5 whose mothers had received either specialized cognitive-behavioural therapy or routine care for depression while pregnant. Of the original cohort of 54 women, renewed consent was given by 28 women for 2-year follow-up and by 24 women for 5-year follow-up. Child assessments at the 2-year follow-up included the Parenting Stress Index (PSI), Bayley Scales of Infant Development (BSID-III) and the Child Behaviour Checklist (CBCL). The 5-year follow-up included the Wechsler Preschool and Primary Scales of Intelligence (WPPSI-III) and again the CBCL. Treatment during pregnancy showed significant benefits for children’s development at age 2, but not at age 5. At 2 years, intervention effects were found with lower scores on the PSI Total score, Parent Domain and Child domain (d=1.44, 1.47, 0.96 respectively). A non-significant trend favoured the intervention group on most subscales of the CBCL and the BSID-III (most notably motor development: d =0.52). In contrast, at 5-year follow-up, no intervention effects were found. Also, irrespective of treatment allocation, higher depression or anxiety during pregnancy was associated with higher CBCL and lower WPPSI-III scores at 5 years. This is one of the first controlled studies to evaluate the long-term effect of antenatal depression treatment on infant neurodevelopmental outcomes, showing some benefit. Nevertheless, caution should be taken interpreting the results because of a small sample size, and larger studies are warranted.
The Foot and Mouth Disease (FMD) epidemic of 2001 clearly illustrated the fragility of the UK's farm animal genetic resources. In particular, millions of sheep were killed by the disease and by the ‘stamping out’ policy chosen for disease control. Loss of genetic resources was not evenly spread throughout the UK, nor throughout the many different sheep breeds that are native to the UK and for which the UK has a formal responsibility for protection to the United Nations. In fact, the FMD epidemic demonstrated for the first time that sheep breeds comprising large numbers of individuals which are commercially farmed, can nevertheless be at considerable risk of extinction. The breeds most affected were those restricted to geographical regions of the UK into which the FMD spread. These regionally important breeds are adapted to their particular regional environments, represent an important living heritage for the UK and are a key component in sustaining the rural economies of sheep farming communities.
The events of 2001 provided clear proof that there are two components of the UK's farm animal genetic resources demanding protection. One component is already recognised as a priority and is composed of the numerically rare breeds of all domesticated species: these are already under the protection of the Rare Breeds Survival Trust (RBST). The second component has not previously been recognised as a priority for protection. The FMD crisis proved that sheep breeds could exist as large numbers of individuals, but nevertheless face extinction due to their regional location. Urgent attention must be focussed on our Heritage Breeds of sheep. The UK has one of the greatest number of native sheep breeds of any country in the world. The Heritage Breeds provide potentially valuable genetic resources for environmental, low-input farming systems.
Heritage GeneBank was founded during the FMD epidemic specifically to protect sheep breeds at threat of extinction from the disease. A group of academic research scientists established a genetic salvage programme: collecting semen and embryos for protection in a gene bank. Germplasm from seven breeds is in long-term storage. Following the crisis, the scientists involved in the gene bank made a commitment to continue their conservation work in recognition that the Heritage Breeds of sheep in the UK continue to require protection.
This paper describes: (1) the work of Heritage GeneBank (HGB); (2) the threefold mission of The Sheep Trust, the new national charity that evolved from HGB (http://www.thesheeptrust.org); and (3) the ongoing urgent need for conservation of the UK's Heritage Breeds of sheep threatened by genetic erosion.
The Darwin–Hatherton Glacial system (DHGS) connects the East Antarctic Ice Sheet (EAIS) with the Ross Ice Shelf and is a key area for understanding past variations in ice thickness of surrounding ice masses. Here we present the first detailed measurements of ice thickness and grounding zone characteristics of the DHGS as well as new measurements of ice velocity. The results illustrate the changes that occur in glacier geometry and ice flux as ice flows from the polar plateau and into the Ross Ice Shelf. The ice discharge and the mean basal ice shelf melt for the first 8.5 km downstream of the grounding line amount to 0.24 ± 0.05 km3 a−1 and 0.3 ± 0.1 m a−1, respectively. As the ice begins to float, ice thickness decreases rapidly and basal terraces develop. Constructed maps of glacier geometry suggest that ice drainage from the EAIS into the Darwin Glacier occurs primarily through a deep subglacial canyon. By contrast, ice thins to <200 m at the head of the much slower flowing Hatherton Glacier. The glaciological field study establishes an improved basis for the interpretation of glacial drift sheets at the link between the EAIS and the Ross Ice Sheet.
We use models constrained by remotely sensed data from Pine Island and Thwaites Glaciers, West Antarctica, to infer basal properties that are difficult to observe directly. The results indicate strong basal melting in areas upstream of the grounding lines of both glaciers, where the ice flow is fast and the basal shear stress is large. Farther inland, we find that both glaciers have ‘mixed’ bed conditions, with extensive areas of both bedrock and weak till. In particular, there are weak areas along much of Pine Island Glacier’s main trunk that could prove unstable if it retreats past the band of strong bed just above its current grounding line. In agreement with earlier studies, our forward ice-stream model shows a strong sensitivity to small perturbations in the grounding line position. These results also reveal a large sensitivity to the assumed bed (sliding or deforming) model, with non-linear sliding laws producing substantially greater dynamic response than earlier simulations that assume a linear-viscous till rheology. Finally, comparison indicates that our results using a plastic bed are compatible with the limited observational constraints and theoretical work that suggests an upper bound exists on maximum basal shear stress.
Basal radar reflectivity is the most important measurement for the detection of subglacial water. However, dielectric loss in the overlying ice column complicates the determination of basal reflectivity. Dielectric attenuation is a function of ice temperature and impurity concentration. Temperature distribution is a function of climate history, basal heat flow and vertical strain rate, all of which can be partially inferred from the structure of dated internal layers. Using 11 dated layers, isotope records from Dome C, East Antarctica, and a model of the spatial variation of geothermal flux, we calculate the vertical strain rate and accumulation-rate history, allowing identification of areas where the basal melt rate exceeds 1.5 mm a−1. The accumulation-rate history and vertical strain rates are then used as inputs for a transient temperature model. The model outputs for the present-day temperature distribution are then combined with depth-dependent ionic concentrations to model dielectric loss and infer basal reflectivity. The resulting reflection coefficients are consistent (∼−5 dB) across a variety of subglacial water bodies. We also identify a high reflectivity >−15 dB in Concordia Trench and along suspected subglacial water-flow routes in Vincennes Basin. Highland areas tend to have highly variable reflection coefficients near −30 dB, consistent with an ice–bedrock interface. This combined model also identifies three areas of enhanced basal melting along Concordia Ridge, Concordia Subglacial Lake and Vincennes Basin. Melt at Concordia Subglacial Lake exceeds 5 mm a−1. The inferred basal melt at these locations is not possible without enhanced geothermal flux. We demonstrate how radar-sounding data can provide both input and verification for a self-consistent model of vertical strain, vertical temperature distribution and meltwater distribution.
Relationships between stable isotopes (δD–δ18O), ice facies and glacier structures have hitherto gone untested in the mid-latitude maritime glaciers of the Southern Hemisphere. Here, we present δD–δ18O values as part of a broader study of the structural glaciology of Fox Glacier, New Zealand. We analyzed 94 samples of δD–δ18O from a range of ice facies to investigate whether isotopes have potential for structural glaciological studies of a rapidly deforming glacier. The δD–δ18O measurements were aided by structural mapping and imagery from terminus time-lapse cameras. The current retreat phase was preceded by an advance of 1 km between 1984 and 2009, with the isotopic sampling and analysis undertaken at the end of that advance (2010/11). Stable isotopes from debris-bearing shear planes near the terminus, interpreted as thrust faults, are isotopically enriched compared with the surrounding ice. When plotted on co-isotopic diagrams (δD–δ18O), ice sampled from the shear planes appears to show a subtle, but distinctive isotopic signal compared with the surrounding clean ice on the lower glacier. Hence, stable isotopes (δD–δ18O) have potential within the structural glaciology field, but larger sample numbers than reported here may be required to establish isotopic contrasts between a broad range of ice facies and glacier structures.
Previous studies have shown that the intake of freeze-dried strawberry powder (FDSP) improves select markers of cardiovascular health in adults with cardiovascular risk factors; however, whether these improvements can be observed in at-risk adolescents is unknown. A randomised, double-blind, cross-over study enrolled twenty-five overweight or obese males, aged 14–18 years, to consume 50 g of a FDSP or a control powder, daily for 1 week. Before and after each test period, measures of microvascular function, plasma nitrate/nitrite, platelet reactivity and blood lipids were collected at baseline and acutely 1 h after FDSP intake. Acute plasma nitrate/nitrite levels increased 1 h after consuming the FDSP during Study Visit 1 before daily FDSP intake (P<0·001) and during Study Visit 2 after 1 week of FDSP intake (P<0·001) compared with control powder intake. As a group, fasting nitrate/nitrite levels did not significantly change after 1 week of control or FDSP intake. However, for those individuals where fasting nitrate levels increased after short-term FDSP intake compared with controls, an increase in reactive hyperaemia index (RHI) was observed (P=0·014), whereas RHI was unchanged in those individuals who did not have a significant increase in nitrate (P=0·396). Taken together, these data support the concept that strawberries can provide vascular health benefits to heavier adolescent males.
Campylobacteriosis is a zoonotic disease which has a worldwide public health impact. The disease is endemic in Egypt; however, the epidemiology in animals and humans has not been fully characterized. The objective of this study was to compare the risk of Campylobacter faecal carriage in children exposed to Campylobacter-infected vs. non-infected backyard poultry and to identify risk factors for a backyard being classified as infected. A total of 103 households which owned backyard poultry were sampled from a rural community in Egypt. Within these households 379 poultry and 106 children were tested for C. jejuni and C. coli; 23·5% and 5·5% of poultry were positive for C. jejuni and C. coli, respectively. In the studied households; 12·3% of children were positive for C. jejuni, and 2·8% were positive for C. coli. Using logistic regression, households with poultry positive for C. jejuni had 3·86 (95% confidence interval 1·0–15·0) times the odds of having children positive for C. jejuni compared to those housed with poultry which all tested negative. Backyard poultry may present a transmission route of C. jejuni to children. Backyards with poor cleaning and disinfection, wet litter and manure disposed of within the backyard had increased odds of being positive for C. jejuni. Enhancing biosecurity and management in poultry backyards may reduce the risk of the disease.
Aims: To determine whether double concussions can result in longer-lasting cognitive dysfunctioning than a single concussion and/or whether cognitive dysfunction is a greater risk factor for double concussions than for a single concussion.
Method: Through a national hospitalisation database, 2753 men were found who, at ages between infancy and early adulthood, had, on two separate occasions, been briefly hospitalised after a concussion. This cohort was compared with a previously obtained and comparable sample of men who had suffered a single concussion. From Draft Board records a dichotomised index was obtained indicating whether or not they had performed at or above a cut-off total score on a cognitive screening test involving four timed subtests, below cut-off being considered as dysfunctional.
Findings: For all age groups, double concussions were associated with higher rates of cognitive dysfunction than single concussions. This was especially true where the concussion(s) had occurred after cognitive testing [odds ratio = 2.53, 95% confidence interval (CI) = 1.92–3.36]. Where double concussions had occurred before cognitive testing but after age 12, cognitive dysfunction was more prevalent when the interval between concussions was less than 1 month than at longer intervals (odds ratio = 3.91, 95%CI = 1.14–13.34). It is concluded that cognitive dysfunction in young men is a risk factor for repeat concussions; at the same time cognitive dysfunction can also be a long-term consequence of two concussions occurring in close temporal proximity.
Convergent electron beam diffraction (CBED) has been successfully applied to measure strain/stress in the channel area in PMOS semiconductor device with embedded SiGe (eSiGe) for 65nm technology. Reliable results of strain/stress measurements in the channel area have been achieved by good fitting of experimental CBED patterns with theoretical calculations. Stress measurements from CBED are in good agreement with simulations. A compressive stress as high as 823.9 MPa was measured in the <110> direction in the channel area of a PMOS device with eSiGe with 15% Ge and a thickness of 80nm. Stress measurements from CBED also confirm that the depth of the eSiGe and defects such as dislocation loops within the eSiGe relax strain/stress within the film and reduce strain/stress in the channel area.
Large particles in fumed silica dispersions were characterized by sedimentation, light scattering techniques, Transmission Electron Microscopy (TEM), and lacunarity. Applying centrifugation to fumed silica dispersions generated differences in sedimentation rates of large particles. The sedimentation rates of the large particles were affected by morphological differences and the particles remaining in the supernatant displayed buoyant behavior. The large particle morphology varied from branch like aggregates containing large primary particles to particles comprised of highly coalesced, tightly packed small primary particles. The results indicate the presence of different types of large particles in fumed silica dispersions to which conventional large particle characterization is unable to distinguish.
PFET devices fabricated using embedded SiGe source/drain on (110) silicon substrates have shown significant performance improvement compared to PFETs with embedded SiGe on (100) SOI substrates. In this paper, we report a systematic material characterization on the epitaxial SiGe films, both on blanket and patterned substrates, and corresponding PFET performance data. The SiGe films were deposited in an RTCVD system. The epitaxial growth rate on (110) substrates was 30% lower than on (100), and 30% higher on patterned device wafers compared to blanket wafers. Films were characterized using an array of methods such as High Resolution XRD (for Ge composition, strain and thickness), Auger (for Ge composition), UV Raman microprobe (for strain), AFM (for surface morphology), and TEM (for epi quality). The Ge compositions determined by XRD and Auger are in excellent agreement (15~16%). The amount of strain extracted from the Raman measurements is also consistent with the amount determined by XRD, which is 0.60%, corresponding to a fully strained Si0.85Ge0.15 film. AFM showed much higher RMS and Rmax for the SiGe films on (110) substrates compared to those on (100) substrates. XTEM showed high crystalline quality with very low defect count in the SiGe source/drain and Si channel regions. PFETs with an embedded Si0.85Ge0.15 source/drain on hybrid orientation (HOT) substrates provided a 30% advantage in drive current and a 23% enhancement in ring oscillator speed compared to control devices on (100) SOI wafer.
Ensembles of indium phosphide nanowires were grown on amorphous quartz substrates and their optical properties were examined at various cryogenic temperatures. Complex dynamics result from the large areal densities, random orientation, combination of both zincblende and wurtzite phases, and the geometries of the nanowires. Those complex dynamics are discussed in relation to their effect on the temperature dependence of photoluminescence and Raman spectroscopy. Five peaks are found to exist in the photoluminescence spectra at low temperatures which are attributed to radiative recombinations associated with quantum confined zinc blende, quantum confined excitons in zinc blende, quantum confined wurtzite, excitons in bulk zinc blende and impurity states. An energy transfer mechanism between two types of radiative recombinations among the five is proposed to explain intensity variations and the temperature dependence of the PL peaks is discussed. The Raman spectra is observed to have peaks created by a combination of zinc blende and wurtzite vibrational modes which is explained by folding the phonon dispersion.
Growth orientation and type of internal structures are both observed to change abruptly as a function of growth temperature in catalyst free growth of gallium nitride nanowires. In the present work, corresponding temperature-dependent changes in the growth matrix substrate that can affect the availability of nucleation sites and influence the reactivity of constituent adatom materials in catalyst-free nanowire growth are investigated. The influence of Ga vapor pressure and an abrupt change in the availability of single versus molecular adatom constituents is identified as a possible controlling parameter.
Antibiotic production by dermatophyte fungi has been demonstrated in vivo in the lesions of patients with dermatomycoses. Patients infected with antibiotic-producing strains more frequently carried cocci resistant to penicillin and other antibiotics than did patients infected with non-producer strains. The total bacterial load was less in lesions caused by producer fungi. In vitro studies demonstrated the selection of penicillin-resistant S. aureus from mixed populations of resistant and sensitive cells.
Amoebae and plasmodia are alternate vegetative forms in the life cycle of the acellular slime mould Physarum polycephalum. Haploid amoebae carrying heterothallic alleles of the matA (or mt) locus ordinarily form plasmodia only by crossing, but occasionally give rise to mutants that form plasmodia by selfing as well as by crossing. Twelve independently isolated mutants of this type have been studied. Eight carry mutations (termed gad or greater asexual differentiation mutations) within approximately 0·2 map units of matA. Another mutation (gad-12) is linked neither to matA nor to any of 9 other markers tested. The remaining three mutations are linked to matA and map as follows: matA–0·5 units – gad-4–4 units – gad-6 – 8 units – gad-11. One mutation, gad-11, has been tested in strains carrying each of the five matA alleles (matAl, 2, 3, 4, and h) available in a common genetic background; the mutation is expressed with all five alleles. The mutation npfF1 (formerly aptA1), which was isolated as a suppressor of selfing in Colonia (matAh) amoebae, suppresses the action of each of the 12 gad mutations. The similarly isolated mutation npfA1 is also epistatic to eight of the mutations, but permits selfing with gad-5, 6, 12 and 13. For double mutant strains containing gad-12 and gad-1, 2, 4, 6 or 11, the selfing behaviour of each double mutant differs from that of either single mutant. Mixtures of gad−npfF1 with gad+npf+ amoebae readily form plasmodia, a result suggesting that gad mutations are dominant or semi-dominant. We conclude that the commitment of a cell to differentiate into a plasmodium is under the control of a complex group of genes linked to matA.