Efficient algorithms for pairing-based cryptosystems

We describe fast new algorithms to implement recent cryptosystems based on the Tate pairing. In particular, our techniques improve pairing evaluation speed by a factor of about 55 compared to previously known methods in characteristic 3, and attain performance comparable to that of RSA in larger characteristics.We also propose faster algorithms for scalar multiplication in characteristic 3 and square root extraction over Fpm, the latter technique being also useful in contexts other than that of pairing-based cryptography

Carbon burial in deep-sea sediment and implications for oceanic inventories of carbon and alkalinity over the last glacial cycle

Although it has long been assumed that the glacial–interglacial cycles of atmospheric CO2 occurred due to increased storage of CO2 in the ocean, with no change in the size of the active carbon inventory, there are signs that the geological CO2 supply rate to the active pool varied significantly. The resulting changes of the carbon inventory cannot be assessed without constraining the rate of carbon removal from the system, which largely occurs in marine sediments. The oceanic supply of alkalinity is also removed by the burial of calcium carbonate in marine sediments, which plays a major role in air–sea partitioning of the active carbon inventory. Here, we present the first global reconstruction of carbon and alkalinity burial in deep-sea sediments over the last glacial cycle. Although subject to large uncertainties, the reconstruction provides a first-order constraint on the effects of changes in deep-sea burial fluxes on global carbon and alkalinity inventories over the last glacial cycle. The results suggest that reduced burial of carbonate in the Atlantic Ocean was not entirely compensated by the increased burial in the Pacific basin during the last glacial period, which would have caused a gradual buildup of alkalinity in the ocean. We also consider the magnitude of possible changes in the larger but poorly constrained rates of burial on continental shelves, and show that these could have been significantly larger than the deep-sea burial changes. The burial-driven inventory variations are sufficiently large to have significantly altered the δ13C of the ocean–atmosphere carbon and changed the average dissolved inorganic carbon (DIC) and alkalinity concentrations of the ocean by more than 100&thinsp;µM, confirming that carbon burial fluxes were a dynamic, interactive component of the glacial cycles that significantly modified the size of the active carbon pool. Our results also suggest that geological sources and sinks were significantly unbalanced during the late Holocene, leading to a slow net removal flux on the order of 0.1&thinsp;PgC&thinsp;yr−1 prior to the rapid input of carbon during the industrial period.</p

Effect of agroclimatic variability on land suitability for cultivating rubber (Hevea brasiliensis) and growth performance assessment in the tropical rainforest climate of Peninsular Malaysia

Climate change directly alters climate conditions and indirectly impacts land suitability for cultivating rubber. The Malaysian tropical rainforest climate with regular rainfall of about 2000–2500 mm per year and the average temperature of 26–28 °C provide a suitable condition for planting rubber commercially. There is doubt about how well rubber plants will perform in the future because of climate change. The main question of whether rubber is still appropriate for planting in Peninsular Malaysia must be answered conclusively as rubber requires an approximately 30 year investment in one cycle. This question is particularly relevant in Malaysia as its rubber production is dependent on smallholders. Smallholders contribute approximately 93% of natural rubber production and furthermore, 93% of the rubber land area in Malaysia is owned by smallholders. An agroclimatic map produced in this study will help smallholders in deciding whether to proceed with rubber or change to other valuable crops based on their specific location. In this study, we evaluate 21st century land suitability for cultivating rubber and assess its growth based on climatic data for the Historical (1970–2000), Early (2010–2040), Middle (2040–2070) and End (2070–2100) projections periods. We use the Hevea 1.0 static model for rubber tree modelling to calculate the agroclimatic indices and estimate 30 years’ of actual rubber growth (girth) for all study periods. We find that climate change is predicted to have a positive impact on rubber-suitability in tropical rainforest in Malaysia climates at least until 2100. The End period, where the precipitation and temperature are projected to experience significant increases, becomes more favourable to rubber. The Perak region shows the highest increase in estimated rubber growth in the Early, Middle, and End periods by 16.3%, 31.9% and 39.4%, respectively. Among all regions, Kelang is predicted to be the most suitable area to plant rubber during the Early period as it has a potential estimated girth of up to 94.5 cm. Meanwhile, Johor is predicted to be the best place to cultivate rubber during the Middle and End periods with growth estimations of 97 cm and 99.5 cm, respectively. We indicate that about 32% of existing planted rubber area in Peninsular Malaysia is in Class 6 of land suitability to cultivate rubber

The impact of atmospheric pCO2 on carbon isotope ratios of the atmosphere and ocean

It is well known that the equilibration timescale for the isotopic ratios 13C/12C and 14C/12C in the ocean mixed layer is on the order of a decade, 2 orders of magnitude slower than for oxygen. Less widely appreciated is the fact that the equilibration timescale is quite sensitive to the speciation of dissolved inorganic carbon (DIC) in the mixed layer, scaling linearly with the ratio DIC/CO2, which varies inversely with atmospheric pCO2. Although this effect is included in models that resolve the role of carbon speciation in air-sea exchange, its role is often unrecognized, and it is not commonly considered in the interpretation of carbon isotope observations. Here we use a global three-dimensional ocean model to estimate the redistribution of the carbon isotopic ratios between the atmosphere and ocean due solely to variations in atmospheric pCO2. Under Last Glacial Maximum (LGM) pCO2, atmospheric Δ14C is increased by ~30‰ due to the speciation change, all else being equal, raising the surface reservoir age by about 250 years throughout most of the ocean. For 13C, enhanced surface disequilibrium under LGM pCO2 causes the upper ocean, atmosphere, and North Atlantic Deep Water δ13C to become at least 0.2‰ higher relative to deep waters ventilated by the Southern Ocean. Conversely, under high pCO2, rapid equilibration greatly decreases isotopic disequilibrium. As a result, during geological periods of high pCO2, vertical δ13C gradients may have been greatly weakened as a direct chemical consequence of the high pCO2, masquerading as very well ventilated or biologically dead Strangelove Oceans. The ongoing anthropogenic rise of pCO2 is accelerating the equilibration of the carbon isotopes in the ocean, lowering atmospheric Δ14C and weakening δ13C gradients within the ocean to a degree that is similar to the traditional fossil fuel “Suess” effect

A DR4:tBID axis drives the p53 apoptotic response by promoting oligomerization of poised BAX

The cellular response to p53 activation varies greatly in a stimulus‐ and cell type‐specific manner. Dissecting the molecular mechanisms defining these cell fate choices will assist the development of effective p53‐based cancer therapies and also illuminate fundamental processes by which gene networks control cellular behaviour. Using an experimental system wherein stimulus‐specific p53 responses are elicited by non‐genotoxic versus genotoxic agents, we discovered a novel mechanism that determines whether cells undergo proliferation arrest or cell death. Strikingly, we observe that key mediators of cell‐cycle arrest (p21, 14‐3‐3σ) and apoptosis (PUMA, BAX) are equally activated regardless of outcome. In fact, arresting cells display strong translocation of PUMA and BAX to the mitochondria, yet fail to release cytochrome C or activate caspases. Surprisingly, the key differential events in apoptotic cells are p53‐dependent activation of the DR4 death receptor pathway, caspase 8‐mediated cleavage of BID, and BID‐dependent activation of poised BAX at the mitochondria. These results reveal a previously unappreciated role for DR4 and the extrinsic apoptotic pathway in cell fate choice following p53 activation.Fil: Henry, Ryan E. State University Of Colorado-boulder; Estados UnidosFil: Andrysik, Zdenek. State University Of Colorado-boulder; Estados UnidosFil: Paris, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; Argentina. State University Of Colorado-boulder; Estados UnidosFil: Galbraith, Matthew D.. State University Of Colorado-boulder; Estados UnidosFil: Espinosa, Joaquín M.. State University Of Colorado-boulder; Estados Unido

A novel estimate of ocean oxygen utilisation points to a reduced rate of respiration in the ocean interior

The Apparent Oxygen Utilisation (AOU) is a classical measure of the amount of oxygen respired in the ocean's interior. We show that AOU systematically overestimates True Oxygen Utilisation (TOU) in 6 coupled circulation-biogeochemical ocean models. This is due to atmosphere–ocean oxygen disequilibria in the subduction regions, consistent with previous work. We develop a simple, new, observationally-based approach which we call Evaluated Oxygen Utilisation (EOU). In this approach, we take into account the impact of the upper ocean oxygen disequilibria into the interior, considering that transport takes place predominantly along isopycnal surfaces. The EOU approximates the TOU with less than half of the bias of AOU in all 6 models despite large differences in the physical and biological components of the models. Applying the EOU approach to a global observational dataset yields an oxygen consumption rate 25% lower than that derived from AOU-based estimates, for a given ventilation rate

Evaluating Software Development: A Case Study with Pasture Land Management (PLMS) Grazing Software

A process for evaluating and improving public domain software is presented for agents and faculty who author software and Web-based training. Extension, education, and conservation employees participated in workshops to learn about a Pasture Land Management System software program that enables farmers to experiment with alternative grazing methods. Users were questioned at initial workshop training and again 6 months later. The workshop evaluation showed concern about the software complexity. The follow-up questionnaire revealed the respondents\u27 priorities for technical improvements. The authors used the participants\u27 feedback to evaluate existing problems and prioritize improvements in the usability and functionality of the software

Antimatter-driven fusion propulsion scheme for solar system exploration

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76531/1/AIAA-23527-891.pd

Pasture Land Management System Decision Support Software

Controlled or rotational grazing provides benefits to producers and society through profitable and sound management of grazing land and livestock. Pasture land management system (PLMS) is a decision support system developed to help university, government, and professionals provide technical pasture management assistance to beef and dairy producers. The PLMS focuses on the balance between seasonal forage supply and nutrient demand in a dairy or beef cattle operation. It allows users to explore and compare alternatives (dividing fields into multiple paddocks, changing stocking rates, and forage species) through a visual display and embedded simulation. Users enter a description of the farm by drawing a map. Maps can be drawn freehand, traced over a scanned image, or GIS data may be incorporated. Once map and field data are entered the grazing options are specified via input screens. Grazing systems can be easily compared without economic risk and with almost immediate feedback on how these alternative systems affect variables like milk production and pounds of beef sold. PLMS serves as both an educational tool and a strategic planning tool for evaluating alternative grazing operations and management related investments (website: http://clic.cses.vt.edu/PLMS/)

Western U.S. lake expansions during Heinrich stadials linked to Pacific Hadley circulation

Unidad de excelencia María de Maeztu MdM-2015-0552Lake and cave records show that winter precipitation in the southwestern United States increased substantially during millennial-scale periods of Northern Hemisphere winter cooling known as Heinrich stadials. However, previous work has not produced a clear picture of the atmospheric circulation changes driving these precipitation increases. Here, we combine data with model simulations to show that maximum winter precipitation anomalies were related to an intensified subtropical jet and a deepened, southeastward-shifted Aleutian Low, which together increased atmospheric river-like transport of subtropical moisture into the western United States. The jet and Aleutian Low changes are tied to the southward displacement of the intertropical convergence zone and the accompanying intensification of the Hadley circulation in the central Pacific. These results refine our understanding of atmospheric changes accompanying Heinrich stadials and highlight the need for accurate representations of tropical-extratropical teleconnections in simulations of past and future precipitation changes in the region