JURNAL AGROTEKNOLOGI
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Demons in the North Atlantic: Variability of deep ocean ventilation
No full textTranslation of atmospheric forcing variability into the ocean interior via ocean ventilation is an important aspect of transient climate change. On a seasonal timescale in the subtropics, this translation is mediated by a so‐called “Demon” that prevents access to all except late‐winter mixed‐layer water. Here, we use an eddy‐permitting numerical circulation model to investigate a similar process operating on longer (interannual) timescales in the subpolar North Atlantic. We find that variations in atmospheric forcing are mediated in their translation to the ocean interior, with year‐to‐year changes in the late‐winter mixed layer depth being the critical factor. The signature of persistent strong atmospheric forcing driving deep mixed layers is preferentially ventilated to the interior when the forcing is ceased. Susceptibility to this effect depends on the location and density of subduction — with the rate at which newly ventilated water escapes its region of subduction being the crucial factor
Bound and filed: a seventeenth-century service indenture from a scattered archive
No full textThe history of indentured migration to seventeenth-century English America relies heavily on a single body of sources known as the London record, a collection of contracts and registrations of servants who emigrated from the capital between 1683 and 1686. Of the original 1,000 contracts, 189 have long been considered to be missing. This article uses methods from the study of paperwork and print culture to demonstrate that Huntington Library item HM 1365 is one of those missing contracts. Read as a part of its parent collection, this indenture is evidence of how the writing and archiving of late seventeenth-century transatlantic service contracts functioned to constrain would-be servants' choices and protections during recruitment and servitude, while legitimizing new and exploitative practices in colonial labor relations
Mechanistic insight into the active centers of single/dual-atom Ni/Fe-based oxygen electrocatalysts
No full textSingle-atom catalysts with maximum metal utilization efficiency show great potential for sustainable catalytic applications and fundamental mechanistic studies. We here provide a convenient molecular tailoring strategy based on graphitic carbon nitride as support for the rational design of single-site and dual-site single-atom catalysts. Catalysts with single Fe sites exhibit impressive oxygen reduction reaction activity with a half-wave potential of 0.89 V vs. RHE. We find that the single Ni sites are favorable to promote the key structural reconstruction into bridging Ni-O-Fe bonds in dual-site NiFe SAC. Meanwhile, the newly formed Ni-O-Fe bonds create spin channels for electron transfer, resulting in a significant improvement of the oxygen evolution reaction activity with an overpotential of 270 mV at 10 mA cm−2. We further reveal that the water oxidation reaction follows a dual-site pathway through the deprotonation of *OH at both Ni and Fe sites, leading to the formation of bridging O2 atop the Ni-O-Fe sites
Cognitive and social activities and long-term dementia risk: the prospective UK Million Women Study
No full textBackground
Although dementia is associated with non-participation in cognitive and social activities, this association might merely reflect the consequences of dementia, rather than any direct effect of non-participation on the subsequent incidence of dementia. Because of the slowness with which dementia can develop, unbiased assessment of any such direct effects must relate non-participation in such activities to dementia detection rates many years later. Prospective studies with long-term follow-up can help achieve this by analysing separately the first and second decade of follow-up. We report such analyses of a large, 20-year study.
Methods
The UK Million Women Study is a population-based prospective study of 1·3 million women invited for National Health Service (NHS) breast cancer screening in median year 1998 (IQR 1997–1999). In median year 2001 (IQR 2001–2003), women were asked about participation in adult education, groups for art, craft, or music, and voluntary work, and in median year 2006 (IQR 2006–2006), they were asked about reading. All participants were followed up through electronic linkage to NHS records of hospital admission with mention of dementia, the first mention of which was the main outcome. Comparing non-participation with participation in a particular activity, we used Cox regression to assess fully adjusted dementia risk ratios (RRs) during 0–4, 5–9, and 10 or more years, after information on that activity was obtained.
Findings
In 2001, 851 307 women with a mean age of 60 years (SD 5) provided information on participation in adult education, groups for art, craft, or music, and voluntary work. After 10 years, only 9591 (1%) had been lost to follow-up and 789 339 (93%) remained alive with no recorded dementia. Follow-up was for a mean of 16 years (SD 3), during which 31 187 (4%) had at least one hospital admission with mention of dementia, including 25 636 (3%) with a hospital admission with dementia mentioned for the first time 10 years or more after follow-up began. Non-participation in cognitive or social activities was associated with higher relative risks of dementia detection only during the first decade after participation was recorded. During the second decade, there was little association. This was true for non-participation in adult education (RR 1·04, 99% CI 0·98–1·09), in groups for art, craft, or music (RR 1·04, 0·99–1·09), in voluntary work (RR 0·96, 0·92–1·00), or in any of these three (RR 0·99, 0·95–1·03). In 2006, 655 118 women provided information on reading. For non-reading versus any reading, there were similar associations with dementia, again with strong attenuation over time since reading was recorded, but longer follow-up is needed to assess this reliably.
Interpretation
Life has to be lived forwards, but can be understood only backwards. Long before dementia is diagnosed, there is a progressive reduction in various mental and physical activities, but this is chiefly because its gradual onset causes inactivity and not because inactivity causes dementia.
Funding
UK Medical Research Council, Cancer Research UK
Cherchez la femme: John Keats and Mrs Jones
No full textKeats and Mrs Jones had a thing going on. They had a feeling that it was wrong, so they kept very quiet about it. Keats never mentioned her name in writing and only referred to her in two letters to George and Georgiana, his brother and sister-in-law in America. Her identity has always remained a puzzle, leading some biographers to frustration and others to outlandish speculation
Filgotinib-treated rheumatoid arthritis patients with high baseline neutrophil-to-lymphocyte ratio show better clinical response rates and patient-reported outcomes
No full textFluorinated derivatives of pyridine-2,4-dicarboxylate are potent inhibitors of human 2-oxoglutarate dependent oxygenases
No full text2-Oxoglutarate (2OG) oxygenases have important roles in human biology and are validated medicinal chemistry targets. Improving the selectivity profile of broad-spectrum 2OG oxygenase inhibitors may help enable the identification of selective inhibitors for use in functional assignment work. We report the synthesis of F- and CF3-substituted derivatives of the broad-spectrum 2OG oxygenase inhibitor pyridine-2,4-dicarboxylate (2,4-PDCA). Their inhibition selectivity profile against selected functionally distinct human 2OG oxygenases was determined using mass spectrometry-based assays. F-substituted 2,4-PDCA derivatives efficiently inhibit the 2OG oxygenases aspartate/asparagine-β-hydroxylase (AspH) and the JmjC lysine-specific Nε-demethylase 4E (KDM4E); The F- and CF3-substituted 2,4-PDCA derivatives were all less efficient inhibitors of the tested 2OG oxygenases than 2,4-PDCA itself, except for the C5 F-substituted 2,4-PDCA derivative which inhibited AspH with a similar efficiency as 2,4-PDCA. Notably, the introduction of a F- or CF3-substituent at the C5 position of 2,4-PDCA results in a substantial increase in selectivity for AspH over KDM4E compared to 2,4-PDCA. Crystallographic studies inform on the structural basis of our observations, which exemplifies how a small change on a 2OG analogue can make a substantial difference in the potency of 2OG oxygenase inhibition
A high speed retro-reflective free space optics links with UAV
No full textIn this work we report the design and
implementation of a very high speed retro-reflective free space
communication system between a ground station and a
commercial unmanned aerial vehicle (UAV). The system uses a
pixelated electro-absorption modulator (EAM) modulating retroreflector (MRR) to establish a data link operating at 500 Mbps at
a range of 560 m and a bit error rate (BER) of 7.6·10-4
. The MRR
provides an effective aperture of 11mm and full field of view
(FFOV) of 6.4°. To the best of our knowledge, this is the fastest
demonstration of an outdoor link of this type. In this paper the
design and implementation of the system is described, as well as
results from experimental trials