An appraisal of nutrient supplies available for tree growth in a pumice soil

Chemical analyses have confirmed and explained the results of an earlier pot trial in which the availability of major nutrients in six pumice ash layers of Kaingaroa silty sand was assessed by the growth of radiata pine seedlings. Almost all of the tree-available P is found in the present topsoil: the quantities-of P that occur in two buried soils (Waimihia and Rotoma ashes) are almost entirely in the form of organic P which is apparently very resistant to breakdown due to complexing with allophane. The N in these layers is similarly unavailable. The mineral layers, about 4 ft in thickness (Taupo pumice and lapilli), which lie between the present topsoil and the uppermost buried soil, are very low in total N and P and exchangeable Mg, but relatively high in exchangeable K. Only the lower buried soil contains a reasonable quantity of exchangeable Mg and has a Mg : K ratio in favour of Mg

Working memory replay prioritizes weakly attended events

One view of working memory posits that maintaining a series of events requires their sequential and equal mnemonic replay. Another view is that the content of working memory maintenance is prioritized by attention. We decoded the dynamics for retaining a sequence of items using magnetoencephalography, wherein participants encoded sequences of three stimuli depicting a face, a manufactured object, or a natural item and maintained them in working memory for 5000 ms. Memory for sequence position and stimulus details were probed at the end of the maintenance period. Decoding of brain activity revealed that one of the three stimuli dominated maintenance independent of its sequence position or category; and memory was enhanced for the selectively replayed stimulus. Analysis of event-related responses during the encoding of the sequence showed that the selectively replayed stimuli were determined by the degree of attention at encoding. The selectively replayed stimuli had the weakest initial encoding indexed by weaker visual attention signals at encoding. These findings do not rule out sequential mnemonic replay but reveal that attention influences the content of working memory maintenance by prioritizing replay of weakly encoded events. We propose that the prioritization of weakly encoded stimuli protects them from interference during the maintenance period, whereas the more strongly encoded stimuli can be retrieved from long-term memory at the end of the delay period

Repacking ‘privacy’ for a networked world

In this paper we examine the notion of privacy as promoted in the digital economy and how it has been taken up as a design challenge in the fields of CSCW, HCI and Ubiquitous Computing. Against these prevalent views we present an ethnomethodological study of digital privacy practices in 20 homes in the UK and France, concentrating in particular upon people’s use of passwords, their management of digital content, and the controls they exercise over the extent to which the online world at large can penetrate their everyday lives. In explicating digital privacy practices in the home we find an abiding methodological concern amongst members to manage the potential ‘attack surface’ of the digital on everyday life occasioned by interaction in and with the networked world. We also find, as a feature of this methodological preoccupation, that privacy dissolves into a heterogeneous array of relationship management practices. Accordingly we propose that ‘privacy’ has little utility as a focus for design, and suggest instead that a more productive way forward would be to concentrate on supporting people’s evident interest in managing their relationships in and with the networked world

Diagnosis of Methionine/Valine Variant Creutzfeldt-Jakob Disease by Protein Misfolding Cyclic Amplification

A patient with a heterozygous variant of Creutzfeldt-Jakob disease (CJD) with a methionine/valine genotype at codon 129 of the prion protein gene was recently reported. Using an ultrasensitive and specific protein misfolding cyclic amplification–based assay for detecting variant CJD prions in cerebrospinal fluid, we discriminated this heterozygous case of variant CJD from cases of sporadic CJD

A long-term perspective on a modern drought in the American Southeast

The depth of the 2006-9 drought in the humid, southeastern US left several metropolitan areas with only a 60-120 day water supply. To put the region's recent drought variability in a long-term perspective, a dense and diverse tree-ring network—including the first records throughout the Apalachicola-Chattahoochee-Flint river basin—is used to reconstruct drought from 1665 to 2010 CE. The network accounts for up to 58.1% of the annual variance in warm-season drought during the 20th century and captures wet eras during the middle to late 20th century. The reconstruction shows that the recent droughts are not unprecedented over the last 346 years. Indeed, droughts of extended duration occurred more frequently between 1696 and 1820. Our results indicate that the era in which local and state water supply decisions were developed and the period of instrumental data upon which it is based are amongst the wettest since at least 1665. Given continued growth and subsequent industrial, agricultural and metropolitan demand throughout the southeast, insights from paleohydroclimate records suggest that the threat of water-related conflict in the region has potential to grow more intense in the decades to come

Subsistence Strategies in Traditional Societies Distinguish Gut Microbiomes

Recent studies suggest that gut microbiomes of urban-industrialized societies are different from those of traditional peoples. Here we examine the relationship between lifeways and gut microbiota through taxonomic and functional potential characterization of faecal samples from hunter-gatherer and traditional agriculturalist communities in Peru and an urban-industrialized community from the US. We find that in addition to taxonomic and metabolic differences between urban and traditional lifestyles, hunter-gatherers form a distinct sub-group among traditional peoples. As observed in previous studies, we find that Treponema are characteristic of traditional gut microbiomes. Moreover, through genome reconstruction (2.2-2.5 MB, coverage depth x26-513) and functional potential characterization, we discover these Treponema are diverse, fall outside of pathogenic clades and are similar to Treponema succinifaciens, a known carbohydrate metabolizer in swine. Gut Treponema are found in non-human primates and all traditional peoples studied to date, suggesting they are symbionts lost in urban-industrialized societies

Real time quaking-induced conversion analysis of cerebrospinal fluid in sporadic Creutzfeldt-Jakob disease

OBJECTIVE: Current cerebrospinal fluid (CSF) tests for sporadic Creutzfeldt-Jakob disease (sCJD) are based on the detection of surrogate markers of neuronal damage such as CSF 14-3-3 which are not specific for sCJD. A number of prion protein conversion assays have been developed, including real-time quaking induced conversion (RT-QuIC). The objective of this study is to investigate whether CSF RT-QuIC analysis could be used as a diagnostic test in sCJD. METHODS: An exploratory study was undertaken which analysed 108 CSF samples from patients with neuropathologically confirmed sCJD or from control patients. Of the 108 CSF samples 56 were from sCJD patients (30 female, 26 male, aged 31–84 years; 62.3 ± 13.5 years) and 52 were from control patients (26 female, 26 male, aged 43–84 years; 67.8 ± 10.4 years). A confirmatory group of 118 patients were subsequently examined which consisted of 67 cases of neuropathologically confirmed sCJD (33 female, 34 male, aged 39–82 years; 67.5 ± 9.0 years) and 51 control cases (26 female, 25 male, aged 36–87 years; 63.5 ± 11.6 years). RESULTS: The exploratory study showed that RT-QuIC analysis had a sensitivity of 91% and a specificity of 98% for the diagnosis of sCJD. These results were confirmed in the confirmatory study which showed that CSF RT-QuIC analysis had a sensitivity and specificity of 87% and 100% respectively. INTERPRETATION: This study shows that CSF RT-QuIC analysis has the potential to be a more specific diagnostic test for sCJD than current CSF tests

Dura mater-associated Creutzfeldt-Jakob disease:experience from surveillance in the UK

Between 1970 and 2003, seven cases of human dura mater‐associated Creutzfeldt–Jakob disease (CJD) were identified in the UK. Furthermore, we identified a case of CJD in a porcine dura graft recipient. The mean incubation period of the human dura mater cases was 93 (range 45–177) months. The clinico‐pathological features of the cases are described and compared with cases previously reported in the world literature