Please note, due to essential maintenance online transactions will not be possible between 02:30 and 04:00 BST, on Tuesday 17th September 2019 (22:30-00:00 EDT, 17 Sep, 2019). We apologise for any inconvenience.
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.
The South Caucasus has been largely absent in broader discussions of prehistoric population aggregation in Greater Eurasia. The authors use remote sensing, surface collection and magnetometry to investigate two hilltop fortress settlements at the margins of the Kura River Basin, with a particular emphasis on satellite settlements around the main hills. The results support a model of settlement growth in which previously mobile groups settled around the fortress, while maintaining a degree of spatial and social separation. The use of multiple survey techniques reveals a complex picture of settlement organisation, with implications for comparative analysis of prehistoric population aggregation models.
Engineered non-wetting surfaces inspired by biological species are of interest in the industry due to their potential applications such as water repelling, self-cleaning, anti-icing, anti-corrosion, anti-fouling, and low fluid drag surfaces. However, the adoption of non-wetting surfaces in large scale industrial applications has been hampered by synthesis techniques that are not easily scalable and the limited long term stability and wear robustness of these surfaces in service. In this study, we demonstrate a simple, low cost, and scalable electrochemical technique to produce robust composite coatings with tunable non-wetting properties. The composite coatings are composed of an ultra-fine grain nickel matrix with embedded hydrophobic cerium oxide ceramic particles. Comprehensive characterization, including wetting property measurements, electron microscopy, focused ion beam analysis, hardness measurements, and abrasive wear testing were performed to establish the structure-property relationships for these materials. The grain refinement of the nickel matrix contributes to the high hardness of the composites. As a result of the bimodal CeO2 particle size, hierarchical roughness is present on the surface of the composite, leading to remarkable non-wetting properties, even after 720 m of abrasive wear.
The Eastern Black Sea region of the South Caucasus contains an extremely rich record of metallurgical remains that is poorly known outside of the former Soviet Union. Large numbers of relatively small smelting sites dot the foothill regions, forming a dispersed, yet large-scale metallurgical landscape. New fieldwork in the region has followed up on earlier Soviet period research, relocating and reanalyzing previously known sites and identifying new ones. This paper presents a series of 33 radiocarbon (14C) dates from copper and iron smelting sites in this region. Dates from copper smelting sites suggest that copper smelting occurred over a shorter and more intense period than previously thought, between about 1300 and 800 BC. Dates from newly discovered iron smelting sites place these activities in two episodes during the Classical-Hellenistic period (ca. 500–200 BC) and the High Medieval period (ca. AD 1050–1400). The dramatic expansion in bronze production immediately prior to the adoption of iron mirrors patterns in other regions of Europe and the Near East, and has implications for understanding the economic contexts in which iron emerged. While the new dates from iron smelting sites provide only an initial outline of the iron production chronology in the region, they represent an important step for resolving outstanding issues from previous investigations.
A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities.
Archaeozoological research of Roman animal bones has a long tradition in Switzerland. In the 1950s, Elisabeth Schmid started analysing bones from the Roman city of Augusta Raurica. On the basis of these analyses she published her Atlas of Animal Bones (1972) which is still in use all over the world today. To date, more than 300,000 bone fragments from different Swiss sites have been analysed. In 2002 a synthesis of Swiss data was published by Jörg Schibler et al.; in that publication, the authors focused on social aspects. They assumed that the Roman animal economy was more or less standardized in the region, and that differences existed mainly between settlement types and within sites. In the last few years, not only have more data been recorded, but also other research questions about functional and regional difference—especially between western and eastern Switzerland (Germania Superior and Raetia)—are becoming more important. These differences show the variability and adaptability of the Roman economy.
The 1999 Ukrainian presidential election took place during a period of extreme political turmoil. The excitement of democracy had waned, the economy spiraled ever downward, and charges of corruption among the administration seemed the harbinger of communist victory. Nevertheless, Ukrainian voters returned Leonid Kuchma to the helm. Thomas F. Klobucar, Arthur H. Miller, and Gwyn Erb investigate this curious result, using a model that combines economic evaluations, the candidates’ personalities, and ideology. Relatively well-developed partisanship is present in Ukraine and was a major influence on voters’ choice. Surprisingly, economic evaluations had little impact on the Ukrainian vote. Instead, party identification, ideology, and leadership trait assessments led Ukrainians to vote for the “democrat.”
Infections and colonization with multidrug-resistant organisms (MDROs) identified >48 hours after hospital admission are considered healthcare-acquired according to the definition of the Centers for Disease Control and Prevention (CDC). Some may originate from delayed diagnosis rather than true acquisition in the hospital, potentially diluting the impact of infection control programs. In addition, such infections are not necessarily reimbursed in a healthcare system based on the diagnosis-related groups (DRGs).
The goal of the study was to estimate the preventable proportion of healthcare-acquired infections in a tertiary care hospital in Switzerland by analyzing patients colonized or infected with MDROs.
All hospitalized patients with healthcare-acquired MDRO infection or colonization (HAMIC) or according to the CDC definition (CDC-HAMIC) were prospectively assessed from 2002 to 2011 to determine whether there was evidence for nosocomial transmission. We utilized an additional work-up with epidemiological, microbiological, and molecular typing data to determine the true preventable proportion of HAMICs.
Overall, 1,190 cases with infection or colonization with MDROs were analyzed; 274 (23.0%) were classified as CDC-HAMICs. Only 51.8% of CDC-HAMICs had confirmed evidence of hospital-acquisition and were considered preventable. Specifically, 57% of MRSA infections, 83.3% of VRE infections, 43.9% of ESBL infections, and 74.1% of non-ESBL MDRO infections were preventable HAMICs.
The CDC definition overestimates the preventable proportion of HAMICs with MDROs by more than 50%. Relying only on the CDC definition of HAMICs may lead to inaccurate measurement of the impact of infection control interventions and to inadequate reimbursement under the DRG system.
The work hardening behavior of electrodeposited nanocrystalline nickel (29 and 19 nm) was investigated under multiaxial loading and compared with coarse-grained nickel. Plastic strain gradients were introduced into the materials using large Rockwell D hardness indentations, and measured through cross-sectional hardness profiles. The results showed that the coarse-grained material exhibited substantial hardening up to twice the hardness of the deformation-free area due to dislocation mediated deformation, while the nanocrystalline materials displayed small hardness variations along the strain gradient, indicative of considerably reduced dislocation interactions. Moreover, the grain structure analysis (cumulative volume fraction and size distribution) for the nanocrystalline materials suggested the operation of both dislocation mediated and grain boundary controlled deformation mechanisms, the latter becoming more significant with increasing cumulative sample volume of very small grains. The plastic deformation zone sizes under Rockwell indentation of the 29 nm Ni are similar to those conventional materials with reduced strain hardening. Microhardness-indentation size effects were negligible in both the nanocrystalline and coarse-grained materials.
This paper presents research in the development of heuristic evolutionary algorithms (EAs) for generating and exploring differentiated force-based structures. The algorithm is weighted toward design exploration of topological differentiation while including specific structural and material constraints. An embryological EA model is employed to “grow” networks of mass-spring elements achieving desired mesh densities that resolve themselves in tensile force (form-active) equilibrium. The primal quadrilateral quadrisection method serves as the foundation for a range of extensible subdivision methods. Unique to this research, the quad is addressed as a “cell” rather than a topological or geometric construct, allowing for the contents of the cell to vary in number of mass-spring elements and orientation. In this research, this approach has been termed the quadrilateral quadrisection with n variable topological transformation method. This research culminates with the introduction of a method for grafting meshes where emergent features from the evolved meshes can be transposed and replicated in an explicit yet informed manner. The EA and grafting methods function within a Java-based software called springFORM, developed in previous research, which utilizes a mass-spring based library for solving force equilibrium and allows for both active (manual) and algorithmic topology manipulation. In application to a specific complex tensile mesh, the design framework, which combines the generative EA and mesh grafting method, is shown to produce emergent and highly differentiated topological arrangements that negotiate the specific relationships among a desired maximal mesh density, geometric patterning, and equalized force distribution.
Research suggests that personality traits have both direct and indirect effects on the development of psychological symptoms, with indirect effects mediated by stressful or traumatic events. This study models the direct influence of personality traits on residualized changes in internalizing and externalizing symptoms following a stressful and potentially traumatic deployment, as well as the indirect influence of personality on symptom levels mediated by combat exposure.
We utilized structural equation modeling with a longitudinal prospective study of 522 US National Guard soldiers deployed to Iraq. Analyses were based on self-report measures of personality, combat exposure, and internalizing and externalizing symptoms.
Both pre-deployment Disconstraint and externalizing symptoms predicted combat exposure, which in turn predicted internalizing and externalizing symptoms. There was a significant indirect effect for pre-deployment externalizing symptoms on post-deployment externalizing via combat exposure (p < 0.01). Negative Emotionality and pre-deployment internalizing symptoms directly predicted post-deployment internalizing symptoms, but both were unrelated to combat exposure. No direct effects of personality on residualized changes in externalizing symptoms were found.
Baseline symptom dimensions had significant direct and indirect effects on post-deployment symptoms. Controlling for both pre-exposure personality and symptoms, combat experiences remained positively related to both internalizing and externalizing symptoms. Implications for diagnostic classification are discussed.
Estimates of the prevalence of mild traumatic brain injury (mTBI) among
military personnel and combat veterans rely almost exclusively on
retrospective self-reports; however, reliability of these reports has
received little attention.
To examine the consistency of reporting of mTBI over time and identify
factors associated with inconsistent reporting.
A longitudinal cohort of 948 US National Guard Soldiers deployed to Iraq
completed self-report questionnaire screening for mTBI and psychological
symptoms while in-theatre 1 month before returning home (time 1,
T1) and 1 year later (time 2, T2).
Most respondents (n = 811, 85.5%) were consistent in
their reporting of mTBI across time. Among those who were inconsistent in
their reports (n = 137, 14.5%), the majority denied mTBI
at T1 and affirmed mTBI at T2 (n = 123, 89.8%). Respondents rarely
endorsed mTBI in-theatre and later denied mTBI (n = 14,
10.2% of those with inconsistent reports). Post-deployment post-traumatic
stress symptoms and non-specific physical complaints were significantly
associated with inconsistent report of mTBI.
Military service members' self-reports of mTBI are generally consistent
over time; however, inconsistency in retrospective self-reporting of mTBI
status is associated with current posttraumatic stress symptoms and
non-specific physical health complaints.
Thirty-nine hemodialysis patients with permanent central venous catheters were analyzed for bacterial catheter colonization comparing different catheter-lock strategies. The closed needleless Tego connector with sodium chloride lock solution was significantly more frequently colonized with bacteria than the standard catheter caps with antimicrobially active citrate lock solution (odds ratio, 0.22 [95% confidence interval, 0.07–0.71]; P = .011).