We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save 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 saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
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 saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved 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.
We developed a tilt sensor for studying ice deformation and installed our tilt sensor systems in two boreholes drilled close to the shear margin of Jarvis Glacier, Alaska to obtain kinematic measurements of streaming ice. We used the collected tilt data to calculate borehole deformation by tracking the orientation of the sensors over time. The sensors' tilts generally trended down-glacier, with an element of cross-glacier flow in the borehole closer to the shear margin. We also evaluated our results against flow dynamic parameters derived from Glen's exponential flow law and explored the parameter space of the stress exponent n and enhancement factor E. Comparison with values from ice deformation experiments shows that the ice on Jarvis is characterized by higher n values than that is expected in regions of low stress, particularly at the shear margin (~3.4). The higher n values could be attributed to the observed high total strains coupled with potential dynamic recrystallization, causing anisotropic development and consequently sped up ice flow. Jarvis' n values place the creep regime of the ice between basal slip and dislocation creep. Tuning E towards a theoretical upper limit of 10 for anisotropic ice with single-maximum fabric reduces the n values by 0.2.
Objectives: Studies of neurocognitively elite older adults, termed SuperAgers, have identified clinical predictors and neurobiological indicators of resilience against age-related neurocognitive decline. Despite rising rates of older persons living with HIV (PLWH), SuperAging (SA) in PLWH remains undefined. We aimed to establish neuropsychological criteria for SA in PLWH and examined clinically relevant correlates of SA. Methods: 734 PLWH and 123 HIV-uninfected participants between 50 and 64 years of age underwent neuropsychological and neuromedical evaluations. SA was defined as demographically corrected (i.e., sex, race/ethnicity, education) global neurocognitive performance within normal range for 25-year-olds. Remaining participants were labeled cognitively normal (CN) or impaired (CI) based on actual age. Chi-square and analysis of variance tests examined HIV group differences on neurocognitive status and demographics. Within PLWH, neurocognitive status differences were tested on HIV disease characteristics, medical comorbidities, and everyday functioning. Multinomial logistic regression explored independent predictors of neurocognitive status. Results: Neurocognitive status rates and demographic characteristics differed between PLWH (SA=17%; CN=38%; CI=45%) and HIV-uninfected participants (SA=35%; CN=55%; CI=11%). In PLWH, neurocognitive groups were comparable on demographic and HIV disease characteristics. Younger age, higher verbal IQ, absence of diabetes, fewer depressive symptoms, and lifetime cannabis use disorder increased likelihood of SA. SA reported increased independence in everyday functioning, employment, and health-related quality of life than non-SA. Conclusions: Despite combined neurological risk of aging and HIV, youthful neurocognitive performance is possible for older PLWH. SA relates to improved real-world functioning and may be better explained by cognitive reserve and maintenance of cardiometabolic and mental health than HIV disease severity. Future research investigating biomarker and lifestyle (e.g., physical activity) correlates of SA may help identify modifiable neuroprotective factors against HIV-related neurobiological aging. (JINS, 2019, 25, 507–519)
This collection of essays pays tribute to Nancy Freeman Regalado, a ground-breaking scholar in the field of medieval French literature whose research has always pushed beyond disciplinary boundaries. The articles in the volume reflect the depth and diversity of her scholarship, as well as her collaborations with literary critics, philologists, historians, art historians, musicologists, and vocalists - in France, England, and the United States. Inspired by her most recent work, these twenty-four essays are tied together by a single question, rich in ramifications: how does performance shape our understanding of medieval and pre-modern literature and culture, whether the nature of that performance is visual, linguistic, theatrical, musical, religious, didactic, socio-political, or editorial? The studies presented here invite us to look afresh at the interrelationship of audience, author, text, and artifact, to imagine new ways of conceptualizing the creation, transmission, and reception of medieval literature, music, and art.
EGLAL DOSS-QUINBY is Professor of French at Smith College; ROBERTA L. KRUEGER is Professor of French at Hamilton College; E. JANE BURNS is Professor of Women's Studies and Adjunct Professor of Comparative Literature at the University of North Carolina, Chapel Hill.
Contributors: ANNE AZÉMA, RENATE BLUMENFELD-KOSINSKI, CYNTHIA J. BROWN, ELIZABETH A. R. BROWN, MATILDA TOMARYN BRUCKNER, E. JANE BURNS, ARDIS BUTTERFIELD, KIMBERLEE CAMPBELL, ROBERT L. A. CLARK, MARK CRUSE, KATHRYN A. DUYS, ELIZABETH EMERY, SYLVIA HUOT, MARILYN LAWRENCE, KATHLEEN A. LOYSEN, LAURIE POSTLEWATE, EDWARD H. ROESNER, SAMUEL N. ROSENBERG, LUCY FREEMAN SANDLER, PAMELA SHEINGORN, HELEN SOLTERER, JANE H. M. TAYLOR, EVELYN BIRGE VITZ, LORI J. WALTERS, AND MICHEL ZINK.
Clostridium difficile infection (CDI) is a common hospital-acquired infection. Previous reports on the incidence, risk factors, and impact of CDI on resources in the surgical population are limited. In this context, we study CDI across diverse surgical settings.
METHODS
We prospectively identified patients with laboratory-confirmed postoperative CDI after 40 different general, vascular, or gynecologic surgeries at 52 academic and community hospitals between July 2012 and September 2013. We used multivariable regression models to identify CDI risk factors and to determine the impact of CDI on resource utilization.
RESULTS
Of 35,363 patients, 179 (0.51%) developed postoperative CDI. The highest rates of CDI occurred after lower-extremity amputation (2.6%), followed by bowel resection or repair (0.9%) and gastric or esophageal operations (0.7%). Gynecologic and endocrine operations had the lowest rates (0.1% and 0%, respectively). By multivariable analyses, older age, chronic immunosuppression, hypoalbuminemia (≤3.5 g/dL), and preoperative sepsis were associated with CDI. Use of prophylactic antibiotics was not independently associated with CDI, neither was sex, body mass index (BMI), surgical priority, weight loss, or comorbid conditions. Three procedure groups had higher odds of postoperative CDI: lower-extremity amputations (adjusted odds ratio [aOR], 3.5; P=.03), gastric or esophageal operations (aOR, 2.1; P=.04), and bowel resection or repair (aOR, 2; P=.04). Postoperative CDI was independently associated with increased length of stay (mean, 13.7 d vs 4.5 d), emergency department presentations (18.9 vs 9.1%) and readmissions (38.9% vs 7.2%, all P<.001).
CONCLUSIONS
Incidence of postoperative CDI varies by surgical procedure. Postoperative CDI is also associated with higher rates of extended length of stay, emergency room presentations, and readmissions, which places a potentially preventable burden on hospital resources.
Nanomedicine is yielding new and improved treatments and diagnostics for a range of diseases and disorders. Nanomedicine applications incorporate materials and components with nanoscale dimensions (often defined as 1-100 nm, but sometimes defined to include dimensions up to 1000 nm, as discussed further below) where novel physiochemical properties emerge as a result of size-dependent phenomena and high surface-to-mass ratio. Nanotherapeutics and in vivo nanodiagnostics are a subset of nanomedicine products that enter the human body. These include drugs, biological products (biologics), implantable medical devices, and combination products that are designed to function in the body in ways unachievable at larger scales. Nanotherapeutics and in vivo nanodiagnostics incorporate materials that are engineered at the nanoscale to express novel properties that are medicinally useful. These nanomedicine applications can also contain nanomaterials that are biologically active, producing interactions that depend on biological triggers. Examples include nanoscale formulations of insoluble drugs to improve bioavailability and pharmacokinetics, drugs encapsulated in hollow nanoparticles with the ability to target and cross cellular and tissue membranes (including the bloodbrain barrier) and to release their payload at a specific time or location, imaging agents that demonstrate novel optical properties to aid in locating micrometastases, and antimicrobial and drug-eluting components or coatings of implantable medical devices such as stents.
Studies of recently isolated populations are useful because observed differences can often be attributed to current environmental variation. Two populations of the lizard Anolis lemurinus have been isolated on the islands of Cayo Menor and Cayo Mayor in the Cayos Cochinos Archipelago of Honduras for less than 15 000 y. We measured 12 morphometric and 10 habitat-use variables on 220 lizards across these islands in 2 y, 2008 and 2009. The goals of our study were (1) to explore patterns of sexual dimorphism, and (2) to test the hypothesis that differences in environment among islands may have driven divergence in morphology and habitat use despite genetic homogeneity among populations. Although we found no differences among sexes in habitat use, males had narrower pelvic girdles and longer toe pads on both islands. Between islands, males differed in morphology, but neither males nor females differed in habitat use. Our data suggest that either recent selection has operated differentially on males despite low genetic differentiation, or that they display phenotypic plasticity in response to environmental variation. We suggest that patterns may be driven by variation in intrapopulation density or differences in predator diversity among islands.
The key principle of Jean Piaget's genetic epistemology is constructivism. Constructivism rejects old-fashioned rationalism: Knowledge is not made out of special knowledge-parts preformed in each individual knower at birth. It also rejects empiricism: Knowledge does not consist of epistemic pieces impressed on the knower by the environment, whether physical or social. Instead, the knower has to construct knowledge.
Genetic epistemology is a developmental theory of knowledge. It is about what knowledge consists of and how knowledge develops.
Knowledge
What knowledge consists of is not the unique preoccupation of this chapter. However, there is no harm in re-emphasizing certain points, because Piaget's conception is so far removed from those that prevail in contemporary cognitive psychology, artificial intelligence, or philosophy of mind. One can make a reasonable decision (as Boom has, in Chapter 6 of this volume) to characterize his developmental theory in terms of control over experience, where experience is understood in terms, not of information, but of exchanges with an external environment.
But Piaget wanted to keep hold of knowledge rather than yield it to those whose conceptions he thought were inadequate, and we will continue in that vein.
Healthcare data suggest that the incidence and severity of Clostridium difficile infection (CDI) in hospitals are increasing. However, the overall burden of disease and the mortality rate associated with CDI, including the contribution from cases of infection that occur in nursing homes, are poorly understood.
Objective.
To describe the epidemiology, disease burden, and mortality rate of healthcare-onset CDI.
Methods.
In 2006, active public reporting of healthcare-onset CDI, using standardized case definitions, was mandated for all Ohio hospitals and nursing homes. Incidence rates were determined and stratified according to healthcare facility characteristics. Death certificates that listed CDI were analyzed for trends.
Results.
There were 14,329 CDI cases reported, including 6,376 cases at 210 hospitals (5,217 initial cases [ie, cases identified more than 48 hours after admission to a healthcare facility in patients who had not had CDI during the previous 6 months] and 1,159 recurrent cases [ie, cases involving patients who had had CDI during the previous 6 months]) and 7,953 cases at 955 nursing homes (4,880 initial and 3,073 recurrent cases). After adjusting for missing data, the estimated total was 18,200 cases of CDI, which included 7,000 hospital cases (5,700 initial and 1,300 recurrent cases) and 11,200 nursing homes cases (6,900 initial and 4,300 recurrent cases). The rate for initial cases was 6.4-7.9 cases/10,000 patient-days for hospitals and 1.7-2.9 cases/10,000 patient-days for nursing homes. The rate for initial cases in nursing homes decreased during the study (P < .001). Nonpediatric hospital status (P = .011), a smaller number of beds (P = .003), and location in the eastern or northeastern region of the state (P = .011) were each independently associated with a higher rate of initial cases in hospitals. Death certificates for 2006 listed CDI among the causes of death for 893 Ohio residents; between 2000 and 2006, this number increased more than 4-fold.
Conclusion.
Healthcare-onset CDI represents a major public health threat that, when considered in the context of an increasing mortality rate, should justify a major focus on prevention efforts.
