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.
More than 3 million individuals in the United States have epilepsy, and over 50 million worldwide. One million in the United States continue to suffer from seizures, despite medication. Their mortality is twice that of the general population, i.e., about 2% mortality per year.1,2 Surgery for epilepsy has a favorable outcome. Among well-selected patients, 70% are seizure-free after surgery. Many of the remaining patients have seizure frequency greatly reduced, e.g., from twice weekly to twice yearly. Surgical outcome avoids mortality risk, morbidity, and costs of medically refractory seizures, and greatly enhances the patient’s quality of life. Yet only 2000 patients per year undergo resective surgery. Surgery for epilepsy is very underutilized.3
The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
Although evidence shows that attachment insecurity and disorganization increase risk for the development of psychopathology (Fearon, Bakermans-Kranenburg, van IJzendoorn, Lapsley, & Roisman, 2010; Groh, Roisman, van IJzendoorn, Bakermans-Kranenburg, & Fearon, 2012), implementation challenges have precluded dissemination of attachment interventions on the broad scale at which they are needed. The Circle of Security–Parenting Intervention (COS-P; Cooper, Hoffman, & Powell, 2009), designed with broad implementation in mind, addresses this gap by training community service providers to use a manualized, video-based program to help caregivers provide a secure base and a safe haven for their children. The present study is a randomized controlled trial of COS-P in a low-income sample of Head Start enrolled children and their mothers. Mothers (N = 141; 75 intervention, 66 waitlist control) completed a baseline assessment and returned with their children after the 10-week intervention for the outcome assessment, which included the Strange Situation. Intent to treat analyses revealed a main effect for maternal response to child distress, with mothers assigned to COS-P reporting fewer unsupportive (but not more supportive) responses to distress than control group mothers, and a main effect for one dimension of child executive functioning (inhibitory control but not cognitive flexibility when maternal age and marital status were controlled), with intervention group children showing greater control. There were, however, no main effects of intervention for child attachment or behavior problems. Exploratory follow-up analyses suggested intervention effects were moderated by maternal attachment style or depressive symptoms, with moderated intervention effects emerging for child attachment security and disorganization, but not avoidance; for inhibitory control but not cognitive flexibility; and for child internalizing but not externalizing behavior problems. This initial randomized controlled trial of the efficacy of COS-P sets the stage for further exploration of “what works for whom” in attachment intervention.
Hunter-gatherer occupations of the forests of Patagonia are still not well understood compared to those of the open steppe and the coasts. The paucity of forest sites with a thorough chronological framework and the incomplete picture of climate-human dynamics in such environments pose a challenge to understanding the occupations of such habitats. This paper presents recent work at the Las Quemas rockshelter, an archaeological site located in the Andean forests of the Aisén region (44°38’ S) dating between 6100 and 2400 cal B.P. We examine the context of the site, its rock art, and the technological and functional dimensions of its lithic assemblage. By comparing these records with local environmental reconstructions that report forest area fluctuations after the Post-Glacial period, this study provides novel data for a comprehensive regional-scale model of human occupations in central Patagonian forests. Following an initial mid-Holocene occupation, recurring occupational events at the site coincide with a significant contraction of forested area in the region during the late Holocene. The results are discussed in regard to regional archaeological data and current models of forest occupation in Patagonia.
We present new X-ray, EUV, and radio observations of the coronal emission from the RS CVn binaries HR1099 (V711 Tau) and σ2 CrB. RS CVn systems possess coronae that display extreme activity levels and frequent flaring. Our observations provide multiwavelength records of coronal variability and flaring over more than two binary orbits for each system. While the EUV and X-ray spectra show the flare response of the thermal plasma, the radio data give the corresponding information for the nonthermal electron population. The HR1099 data contain one of the most energetic flare outbursts observed from HR1099 that lasts for over 3 days. Coronal flaring is common in these systems and, in fact, is the normal condition.
Suicide is a devastating public health problem and very few biological treatments have been found to be effective for quickly reducing the intensity of suicidal ideation (SI). We have previously shown that a single dose of ketamine, a glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, is associated with a rapid reduction in depressive symptom severity and SI in patients with treatment-resistant depression.
We conducted a randomized, controlled trial of ketamine in patients with mood and anxiety spectrum disorders who presented with clinically significant SI (n = 24). Patients received a single infusion of ketamine or midazolam (as an active placebo) in addition to standard of care. SI measured using the Beck Scale for Suicidal Ideation (BSI) 24 h post-treatment represented the primary outcome. Secondary outcomes included the Montgomery–Asberg Depression Rating Scale – Suicidal Ideation (MADRS-SI) score at 24 h and additional measures beyond the 24-h time-point.
The intervention was well tolerated and no dropouts occurred during the primary 7-day assessment period. BSI score was not different between the treatment groups at 24 h (p = 0.32); however, a significant difference emerged at 48 h (p = 0.047). MADRS-SI score was lower in the ketamine group compared to midazolam group at 24 h (p = 0.05). The treatment effect was no longer significant at the end of the 7-day assessment period.
The current findings provide initial support for the safety and tolerability of ketamine as an intervention for SI in patients who are at elevated risk for suicidal behavior. Larger, well-powered studies are warranted.
Myogenesis is facilitated by four myogenic regulatory factors and is significantly inhibited by myostatin. The objective of the current study was to examine embryonic gene regulation of myostatin/myogenic regulatory factors, and subsequent manipulations of protein synthesis, in broiler embryos under induced hyperammonemia. Broiler eggs were injected with ammonium acetate solution four times over 48 h beginning on either embryonic day (ED) 15 or 17. Serum ammonia concentration was significantly higher (P<0.05) in ammonium acetate injected embryos for both ED17 and ED19 collected samples when compared with sham-injected controls. Expression of mRNA, extracted from pectoralis major of experimental and control embryos, was measured using real-time quantitative PCR for myostatin, myogenic regulatory factors myogenic factor 5, myogenic determination factor 1, myogenin, myogenic regulatory factor 4 and paired box 7. A significantly lower (P<0.01) myostatin expression was accompanied by a higher serum ammonia concentration in both ED17 and ED19 collected samples. Myogenic factor 5 expression was higher (P<0.05) in ED17 collected samples administered ammonium acetate. In both ED17 and ED19 collected samples, myogenic regulatory factor 4 was lower (P⩽0.05) in ammonium acetate injected embryos. No significant difference was seen in myogenic determination factor 1, myogenin or paired box 7 expression between treatment groups for either age of sample collection. In addition, there was no significant difference in BrdU staining of histological samples taken from treated and control embryos. Myostatin protein levels were evaluated by Western blot analysis, and also showed lower myostatin expression (P<0.05). Overall, it appears possible to inhibit myostatin expression through hyperammonemia, which is expected to have a positive effect on embryonic myogenesis and postnatal muscle growth.
The calc-alkaline, gneissic El Shalul granite is the westernmost gneiss dome or core complex within the Arabian–Nubian Shield. Previous studies have indicated that it represents either a window into the underlying pre-Neoproterozoic Sahara metacraton or a melt derived from the metacraton. U–Pb LA-ICP-MS dating of magmatic zircons from two samples of the variably foliated El Shalul pluton gives ages of 637 ± 5 Ma and 630 ± 6 Ma, excluding it from representing exhumed cratonic rocks. The ages are, however, indistinguishable from the age of the Um Ba'anib pluton, constituting the core of the Meatiq Gneiss Dome, as well as several other plutons in the Eastern Desert, indicating an important magmatic pulse in the Arabian–Nubian Shield in Late Cryogenian time. Major and trace element data indicate a within-plate setting. Bulk rock Nd-isotope and Hf-isotope data on zircons from the El Shalul pluton indicate derivation of the primary melt from a relatively juvenile source, either the lower crust of a mid-Neoproterozoic volcanic arc or as a result of fractionation of a mantle-derived mafic melt. Sm–Nd bulk rock isotopic data indicate a model age of c. 720 Ma for the protolith from which the melt was derived. Time-corrected Hf-isotope data obtained on the magmatic zircons indicate that the bulk of the source rock was extracted from the mantle around 810 Ma.
Structured training in endoscopic sinus surgery is essential, considering the serious potential complications. We have developed a detailed endoscopic endonasal surgery training programme, using a lamb's head model. This study aimed to assess the possibilities of using such a model for endoscopic dacryocystorhinostomy training.
Materials and methods:
Dacryocystography was performed on lamb's head models, which were then meticulously dissected, both macroscopically and endoscopically, to assess the nasolacrimal system.
Dacryocystography showed the absence of a lacrimal sac in all the lamb's heads dissected. This result was confirmed by dissection.
Lamb's heads are excellent models with which to teach endoscopic sinus surgery techniques. However, this study clearly demonstrated the absence of a lacrimal sac in all such models dissected. Thus, this animal model is inappropriate for endoscopic dacryocystorhinostomy training.
A defining characteristic of many rainfed tropical agricultural systems is their vulnerability to weather variability. There is now increased attention paid to climate-agriculture links as the world is focused on climate change. This has shown the need for increased understanding of current and future climate and the links to agricultural investment decisions, particularly farmers’ decisions, and that integrated strategies for coping with climate change need to start with managing current climate risk. Research, largely from an Association for Strengthening Agricultural Research in Eastern and Central Africa (ASARECA) project to demonstrate the value of such increased understanding, is presented in this issue of the journal. Key lessons from this research are as follows:
1.Statistical methods of analysis of historical climate data that are relevant to agriculture need not be complex. The most critical point is to describe the climate in terms of events of direct relevance to farming (such as the date of the start of a rainy season) rather than simple standard measures (such as annual total rainfall).
2.Analysis requires access to relevant data, tools and expertise. Daily climate data, both current and historical, are primarily the responsibility of national meteorological services (NMS). Accessing such data, particularly daily data, is not always easy. Including staff from the NMS as research partners, not just data providers, can reduce this problem.
3.Farmers’ perceptions of climate variation, risk and change are complex. They are keenly aware of variability, but there is evidence that they over-estimate risks of negative impacts and thereby fail to make use of good conditions when they occur. There is also evidence that multiple causes of changes are confounded, so farmers who observe decreasing crop production may not be distinguishing between rainfall change and declining soil fertility or other conditions. Hence any project working with farmers’ coping and adaptation to climate must also have access to analyses of observed climate data from nearby recording stations.
4.Mechanisms for reducing and coping with risks are exemplified in pastoral systems that exist in the most variable environments. New approaches to risk transfer, such as index-based insurance, show potential for positive impact.
5.Skilful seasonal forecasts, which give a better indication of the coming season than a simple average, would help farmers take decisions for the coming cropping season. Increasing meteorological knowledge shows that such forecasting is possible for parts of Africa. There are institutional barriers to farmers accessing and using the forecast information. Furthermore, the skill of the forecasts is currently limited so that there are maybe still only a few rational choices for a farmer to make on the basis of a forecast.
With the justified current interest in climate and agriculture, all stakeholders including researchers, data providers, policy developers and extension workers will need to work together to ensure that interventions are based on a correct interpretation of a valid analysis of relevant data.
Rainfall variability, both within and between seasons, is reflected in highly variable crop growth and yields in rainfed agriculture in sub-Saharan Africa and results in varying degrees of weather-induced risk associated with a wide range of crop, soil and water management innovations. In addition there is both growing evidence and concern that changes in rainfall patterns associated with global warming may substantively affect the nature of such risk. Eighty-nine years of daily rainfall data from a site in southern Zambia are analysed. The analyses illustrate approaches to assessing the extent of possible trends in rainfall patterns and the calculation of weather-induced risk associated with the inter- and intra-seasonal variability of the rainfall amounts. Trend analyses use monthly rainfall totals and the number of rain days in each month. No simple trends were found. The daily data were then processed to examine important rain dependent aspects of crop production such as the date of the start of the rains and the risk of a long dry spell, both following planting and around flowering. The same approach is used to assess the risk of examples of crop disease in instances when a ‘weather trigger’ for the disease can be specified. A crop water satisfaction index is also used to compare risks from choices of crops with different maturity lengths and cropping strategies. Finally a different approach to the calculations of these risks fits a Markov chain model to the occurrence of rain, with results then derived from this model. The analyses shows the relevance of this latter approach when relatively short daily rainfall records are available and is illustrated through a comparison of the effects of El Niño, La Niña and Ordinary years on rainfall distribution patterns.
Radiation embrittlement of nuclear reactor pressure vessel steels results from a high number density of nanometer sized Cu-Mn-Ni rich precipitates (CRPs) and sub-nanometer matrix features, thought to be vacancy-solute cluster complexes (VSC). However, questions exist regarding both the composition of the precipitates and the defect character and composition of the matrix features. We present results of positron annihilation spectroscopy (PAS) and small angle neutron scattering (SANS) characterization of irradiated and thermally aged Fe-Cu and Fe-Cu-Mn alloys. These complementary techniques provide insight into the composition and character of both types of nanoscale features. The SANS measurements indicate populations of CRPs and VSCs in both alloys. The CRPs are coarser in the Fe-Cu alloy and the number densities of CRP and VSC increase with the addition of Mn. The PAS involved measuring both the positron lifetimes and the Doppler broadened annihilation spectra in the high momentum region to provide elemental sensitivity at the annihilation site. The spectra in Fe-Cu-Mn specimens thermally aged to peak hardness at 450°C and irradiated at 288°C are nearly identical to elemental Cu. Positron lifetime and spectrum measurements in Fe-Cu specimens irradiated at 288°C clearly show the existence of long lifetime (∼500 ps) open volume defects, which also contain Cu. Thus the SANS and PAS provide a self-consistent picture of nanostructures composed of CRPs and VSCs and tend to discount high Fe concentrations in the CRPs.