The glacial cycles and cosmic rays

The cause of the glacial cycles remains a mystery. The origin is widely accepted to be astronomical since paleoclimatic archives contain strong spectral components that match the frequencies of Earth's orbital modulation. Milankovitch insolation theory contains similar frequencies and has become established as the standard model of the glacial cycles. However, high precision paleoclimatic data have revealed serious discrepancies with the Milankovitch model that fundamentally challenge its validity and re-open the question of what causes the glacial cycles. We propose here that the ice ages are initially driven not by insolation cycles but by cosmic ray changes, probably through their effect on clouds. This conclusion is based on a wide range of evidence, including results presented here on speleothem growth in caves in Austria and Oman, and on a record of cosmic ray flux over the past 220 kyr obtained from the 10Be composition of deep-ocean sediments

A spike of CO2 in the atmosphere at glacial-interglacial boundaries induced by rapid deposition of manganese in the oceans

The model presented here provides an explanation of the rapid response of atmospheric CO2 to increasing solar insolation. In the glacial ocean, during periods of slow, deep water renewal, when less oxygen is supplied to the deep ocean and into sediments, manganese oxide in the sediments is reduced and forms soluble MnCO3 and stays in the water column. The dissolved Mn-carbonate should then reach a concentration of ≥ 10µMol/liter, approximately 5,000 to 104 times larger than it is at present. This is the mode prevailing until deep water formation at high latitudes starts again. As soon as the balance between oxygen and organic matter becomes oxidizing once more, the deposition of MnO2 recommences. Oxidation of dissolved Mn2+CO3 to Mn4+O2 which is a spike of acidity to the ocean, rapidly lowers the CO3−− concentration in the water column and enhances release of CO2 to the atmosphere, producing the observed events of CO2 increase at the transitions from glacials to interglacials. The surprising conclusion is that the oceanic (redox-) cycle of a minor element may have had a major impact on Earth's climate

Thorium and uranium isotopes in a manganese nodule from the Peru basin determined by alpha spectrometry and thermal ionization mass spectrometry (TIMS): Are manganese supply and growth related to climate?

Thorium- and uranium isotopes were measured in a diagenetic manganese nodule from the Peru basin applying alpha- and thermal ionization mass spectrometry (TIMS). Alpha-counting of 62 samples was carried out with a depth resolution of 0.4 mm to gain a high-resolution230Thexcess profile. In addition, 17 samples were measured with TIMS to obtain precise isotope concentrations and isotope ratios. We got values of 0.06–0.59 ppb (230Th), 0.43–1.40 ppm (232Th), 0.09–0.49 ppb (234U) and 1.66–8.24 ppm (238U). The uranium activity ratio in the uppermost samples (1–6 mm) and in two further sections in the nodule at 12.5±1.0 mm and 27.3–33.5 mm comes close to the present ocean water value of 1.144±0.004. In two other sections of the nodule, this ratio is significantly higher, probably reflecting incorporation of diagenetic uranium. The upper 25 mm section of the Mn nodule shows a relatively smooth exponential decrease in the230Thexcess concentration (TIMS). The slope of the best fit yields a growth rate of 110 mm/Ma up to 24.5 mm depth. The section from 25 to 30.3 mm depth shows constant230Thexcess concentrations probably due to growth rates even faster than those in the top section of the nodule. From 33 to 50 mm depth, the growth rate is approximately 60 mm/Ma. Two layers in the nodule with distinct laminations (11–15 and 28–33 mm depth) probably formed during the transition from isotopic stage 8 to 7 and in stage 5e, respectively. The Mn/Fe ratio shows higher values during interglacials 5 and 7, and lower ones during glacials 4 and 6. A comparison of our data with data from adjacent sediment cores suggests (a) a variable supply of hydrothermal Mn to sediments and Mn nodules of the Peru basin or (b) suboxic conditions at the water sediment interface during periods with lower Mn/Fe ratios

The dependence of minimum-time routes over the North Atlantic on cruise altitude

North Atlantic air traffic is broadly organised into a track system; daily sets of tracks are defined by air traffic control which are vertically stacked, such that the same set of tracks is used for all flight levels, regardless of any vertical variations in wind. This work uses minimum-time routes, previously shown to be a good proxy for the location of the North Atlantic track system, to understand whether vertical variations in wind speed and direction significantly affect minimum-time routes optimised at different altitudes; this is to examine whether (all other factors assumed equal) there is potential for improvements in fuel efficiency. The optimum cruise altitude over the North Atlantic is determined, focusing on the New York – London route. It is found that eastbound routes, which take advantage of the jet stream, are on average faster at 250 hPa (flight level (FL) 340) than at 300 hPa (FL300) or 200 hPa (FL390) by approximately 2 minutes (compared to the annual-mean route time of about 330 minutes, assuming a true air speed of 250 m s-1). For westbound routes, the route time increases with height: aircraft flying at 300 hPa are on average 3 minutes faster than at higher levels (the annual-mean optimum time being about 400 minutes). These estimates are compared with the time penalty which arises from flying a route optimized at 250 hPa at the other two altitudes. The time penalty is generally less than a minute, compared to the minimum-time routes calculated at those altitudes

Task demands dissociate the effects of muscarinic M-1 receptor blockade and protein kinase C inhibition on attentional performance in rats

The cholinergic system is known to be necessary for normal attentional processing. However, the receptors and mechanisms mediating the effects of acetylcholine on attention remain unclear. Previous work in our laboratory suggested that cholinergic muscarinic receptors are critical for maintaining performance in an attention-demanding task in rats. We examined the role of the muscarinic M-1 receptor and protein kinase C (PKC), which is activated by the M-1 receptor, in attention task performance. Rats were trained in an attention-demanding task requiring discrimination of brief (500, 100, 25 ms) visual signals from trials with no signal presentation. The effects of muscarinic M-1 receptor blockade were assessed by administering dicyclomine (0-5.0 mg/kg). The effects of PKC inhibition were assessed by administering chelerythrine chloride (0-2.0 mg/kg). Dicyclomine decreased the accuracy of detecting longer signals in this attention task, including when attentional demands were increased by flashing a houselight throughout the session. Chelerythrine chloride decreased the accuracy of signal detection in the standard version of the task but not when the houselight was flashed throughout the session. The present findings indicate that muscarinic M-1 receptors are critical for maintaining performance when attentional demands are increased, and that PKC activity may contribute to some aspects of attentional performance

Candidate genes and quantitative trait loci for grain yield and seed size in durum wheat

Grain yield (YLD) is affected by thousand kernel weight (TKW) which reflects the combination of grain length (GL), grain width (GW) and grain area (AREA). Grain weight is also influenced by heading time (HT) and plant height (PH). To detect candidate genes and quantitative trait loci (QTL) of yield components, a durum wheat recombinant inbred line (RIL) population was evaluated in three field trials. The RIL was genotyped with a 90K single nucleotide polymorphism (SNP) array and a high-density genetic linkage map with 5134 markers was obtained. A total of 30 QTL were detected including 23 QTL grouped in clusters on 1B, 2A, 3A, 4B and 6B chromosomes. A QTL cluster on 2A chromosome included a major QTL for HT co-located with QTL for YLD, TKW, GL, GW and AREA, respectively. The photoperiod sensitivity (Ppd-A1) gene was found in the physical position of this cluster. Serine carboxypeptidase, Big grain 1 and β-fructofuranosidase candidate genes were mapped in clusters containing QTL for seed size. This study showed that yield components and phenological traits had higher inheritances than grain yield, allowing an accurate QTL cluster detection. This was a requisite to physically map QTL on durum genome and to identify candidate genes affecting grain yield

Cyber insurance of information systems: Security and privacy cyber insurance contracts for ICT and helathcare organizations

Nowadays, more-and-more aspects of our daily activities are digitalized. Data and assets in the cyber-space, both for individuals and organizations, must be safeguarded. Thus, the insurance sector must face the challenge of digital transformation in the 5G era with the right set of tools. In this paper, we present CyberSure-an insurance framework for information systems. CyberSure investigates the interplay between certification, risk management, and insurance of cyber processes. It promotes continuous monitoring as the new building block for cyber insurance in order to overcome the current obstacles of identifying in real-time contractual violations by the insured party and receiving early warning notifications prior the violation. Lightweight monitoring modules capture the status of the operating components and send data to the CyberSure backend system which performs the core decision making. Therefore, an insured system is certified dynamically, with the risk and insurance perspectives being evaluated at runtime as the system operation evolves. As new data become available, the risk management and the insurance policies are adjusted and fine-tuned. When an incident occurs, the insurance company possesses adequate information to assess the situation fast, estimate accurately the level of a potential loss, and decrease the required period for compensating the insured customer. The framework is applied in the ICT and healthcare domains, assessing the system of medium-size organizations. GDPR implications are also considered with the overall setting being effective and scalable

Biologia com humor: utilização de charges na divulgação científica

Anais do 3° Encontro Nacional de Jogos e Atividades Lúdicas no Ensino de Química, Física e Biologia (Jalequim - Level III) - Núcleo de Desenvolvimento de Pesquisas em Ensino de Química/Ciências da UNILA (NuDDEQ)O campo das Ciências Biológicas apresenta linguajar e conceitos que, muitas vezes, soam como estranhos ao público em geral. Tal aspecto pode contribuir para um afastamento das pessoas em relação a esta área do conhecimento (SASSERON & CARVALHO, 2011). Desta maneira, é interessante se pensar estratégias de aproximação do linguajar biológico com o cotidiano das pessoas, contribuindo assim para a divulgação científica. Entre as várias possibilidades de estratégias de divulgação científica, o presente trabalho optou por trabalhar a mesma relacionando-a com o humor, utilizando-se charges