Serine biosynthesis with one carbon catabolism represents a novel pathway for ATP generation in cells using alternative glycolysis with zero net ATP production

Recent experimental evidence indicates that some cancer cells have an alternative glycolysis pathway with net zero ATP production, implying that upregulation of glycolysis in these cells may not be related to the generation of ATP. Here we use a genome-scale model of human cell metabolism to investigate the potential metabolic alterations in cells using net zero ATP glycolysis. We uncover a novel pathway for ATP generation that involves reactions from the serine biosynthesis and one-carbon metabolism pathways. This pathway has a predicted two-fold higher flux rate in cells using net zero ATP glycolysis than those using standard glycolysis and generates twice as much ATP with significantly lower rate of lactate- but higher rate of alanine secretion. Thus, in cells using the standard- or the net zero ATP glycolysis pathways a significant portion of the glycolysis flux is always associated with ATP generation, and the ratio between the flux rates of the two pathways determines the rate of ATP generation and lactate and alanine secretion during glycolysis

Charges and fields in a current-carrying wire

Charges and fields in a straight, infinite, cylindrical wire carrying a steady current are determined in the rest frames of ions and electrons, starting from the standard assumption that the net charge per unit length is zero in the lattice frame and taking into account a self-induced pinch effect. The analysis presented illustrates the mutual consistency of classical electromagnetism and Special Relativity. Some consequences of the assumption that the net charge per unit length is zero in the electrons frame are also briefly discussed

Quark zero modes in intersecting center vortex gauge fields

The zero modes of the Dirac operator in the background of center vortex gauge field configurations in $\R^2$ and $\R^4$ are examined. If the net flux in D=2 is larger than 1 we obtain normalizable zero modes which are mainly localized at the vortices. In D=4 quasi-normalizable zero modes exist for intersecting flat vortex sheets with the Pontryagin index equal to 2. These zero modes are mainly localized at the vortex intersection points, which carry a topological charge of $\pm 1/2$. To circumvent the problem of normalizability the space-time manifold is chosen to be the (compact) torus \T^2 and \T^4, respectively. According to the index theorem there are normalizable zero modes on \T^2 if the net flux is non-zero. These zero modes are localized at the vortices. On \T^4 zero modes exist for a non-vanishing Pontryagin index. As in $\R^4$ these zero modes are localized at the vortex intersection points.Comment: 20 pages, 4 figures, LaTeX2e, references added, treatment of ideal vortices on the torus shortene

The Impact of Dispersion on Amplitude and Frequency Noise in a Yb-fiber Laser Comb

We describe a Yb-fiber based laser comb, with a focus on the relationship between net-cavity dispersion and the frequency noise on the comb. While tuning the net cavity dispersion from anomalous to normal, we measure the amplitude noise (RIN), offset frequency (f_CEO) linewidth, and the resulting frequency noise spectrum on f_CEO. We find that the laser operating at zero net-cavity dispersion has many advantages, including an approximately 100x reduction in free-running f_CEO linewidth and frequency noise power spectral density between laser operation at normal and zero dispersion. In this latter regime, we demonstrate a phase-locked f_CEO beat with low residual noise

Cosmological constant and gravitational theory on D-brane

In a toy model we derive the gravitational equation on a self-gravitating curved D-brane. The effective theory on the brane is drastically changed from the ordinal Einstein equation. The net cosmological constant on the brane depends on a tuning between the brane tension and the brane charges. Moreover, non-zero matter stress tensor exists if the net cosmological constant is not zero. This fact indicates a direct connection between matters on the brane and the dark energy.Comment: 6 pages, minor corrections, accepted for publication in Physical Review

Delivering on net zero: Scottish Agriculture

The aim of this study was to identify whether, how and at what cost agricultural GHG emissions in Scotland could be reduced by 35% by 2045. In 2017, Scottish agricultural GHG emissions were estimated to be 7.6 Mt CO2e making the 35% target 2.7 Mt CO2e. Building on previous work by SRUC and others, 37 different measures to reduce GHG emissions were evaluated, focusing on improvements in nitrogen fertiliser use, organic manure/slurry storage and use, mechanisation, soil management, cropping systems and management, livestock nutrition, health and breeding, as well as improved farming systems integrating multiple measures, represented by conservation agriculture, organic farming, pasture-fed livestock production and agroforestry. Land use changes, such as from agriculture to peatland or forestry, as well as non-agricultural activities (including input manufacturing, food processing, retailing and consumption) were outside the scope of the study, although consideration was given to food losses on farms arising from decisions in other sectors. Embodied GHG emissions in inputs and impacts of output changes on other countries were also not assessed. In theory, if taken up 100% and accounting for no interactions, the measures could reduce Scottish agricultural emissions by almost 100%. In practice, there are many reasons why measures might not be implemented in combination, or adopted, by all farmers. We estimated that the most promising measures could potentially deliver 2.9 Mt CO2e annually, or 38% of 2017 GHG emissions, and concluded that the 35% target is achievable by 2045. 75% of Scottish agricultural GHG emissions are related to livestock production. This is not surprising given the importance of grassland and rough grazing in Scottish agriculture, which together account for almost 80% of agricultural land. Given this context, measures focused on tillage crops are relatively unimportant with respect to their potential for GHG reduction. The measures with most potential (all specified on annual basis) that we identified were: a) Reduction in nitrogen fertiliser use. Measures to use nitrogen more efficiently, including better use of organic manures, could potentially generate reductions of nearly 350 kt CO2e, or 13% of the target, within the next 10 years, if adopted on most farms. b) More radical reductions in nitrogen fertiliser use, by encouraging the use of legumes in grassland to eliminate or substantially reduce the need for N fertiliser, could reduce emissions by nearly 300 kt CO2e, or 11% of the target, within the next 15 years, if adopted on 40% of grassland. c) The use of legumes combined with rotational grazing techniques in diverse-species grassland, which help build soil organic matter and sequester carbon, could increase the total benefit to 540 kt or 20% of the target. This could potentially be linked with a pasture-fed livestock approach. d) Reducing methane emissions associated with ruminants by using feed additives including 3NOP, nitrates, probiotics, high dietary fat sources and seaweed derivatives could make a significant contribution. In the case of 3NOP, emissions could be reduced by 265 kt or 10% of the target within 10 years, if adopted on most dairy and some other cattle farms. This would require approval of 3NOP as a feed additive so that it can be marketed, and that at an affordable price. e) Improved animal health and breeding, with increased fertility, growth rates and yields, and reduced morbidity/mortality could reduce total livestock numbers needed to deliver the same output, and deliver 366 kt emission reductions (14% of the target) with 40-50% uptake. f) Organic farming, with 40% uptake, could potentially deliver 730 kt CO2e reductions or 27% of the target. This is a result of combining no synthetic nitrogen fertiliser use with an overall 10% reduction in livestock numbers and the conversion of 20% of tillage land to rotational grassland. The financial impacts of these changes are reduced due to the premium markets for organic food. g) Agroforestry also offers potential for substantial reductions: 570 kt (21% of the target) with 30% uptake. This is assuming 10% of farmland is used for trees, with consequent output reductions for crops and livestock, although with some scope to mitigate this. Despite their emission reduction potential, organic farming and agroforestry both have the disadvantages of higher initial investment costs, greater complexity acting as a disincentive to adoption and longer lead-in times, as well as output reductions that, if demand remains unchanged, could lead to an increased requirement for imports and increased emissions elsewhere. However, the widespread adoption of these approaches would need to be considered in the context of changing human and animal diets, and the potential for reducing food losses and waste also highlighted in the report. The financial assessment of these measures indicates that many are likely to be associated with increased costs and, in the absence of other financial benefits, reduced incomes, which would need to be addressed by policy support in some form. In several cases, reductions in nitrate leaching, ammonia emissions and other impacts leading to improvements in water and air quality could provide further justifications for support. In some cases, the improved productivity, for example associated with improved animal health and breeding, could create a win-win situation, with emissions reduction combined with financial benefits. As most of the measures are unlikely to be driven by market forces, policy interventions are likely to be needed, including: • Farming system payments for innovative approaches (whole or part farm) • Input reduction and improved soil management, including support for advice and investments • Regulatory and fiscal options including input taxes and quotas or tradeable carbon quotas linked to input use and sequestration opportunties • Carbon, nitrogen and sustainability auditing • Training, advice and skills • Improved greenhouse gas monitoring and statistics • Targeted research, and • Dietary change and food waste reduction In almost all cases, the practices and systems that could be adopted are well developed and understood, but actions are needed to ensure that financial and knowledge barriers are addressed in order to facilitate their adoption so that the desired GHG mitigation targets can be achieved

PUSH Buffalo\u27s Net Zero House at 10 Winter St.

PUSH Buffalo acquired the property at 10 Winter Street for $2200 at the City tax foreclosure auction, free and clear of all liens. The house is a single family home that is approximately 1198 sq. ft., with three bedrooms, two bathrooms, a partial basement and a crawl space. The house was originally built in 1920. The farm house style is unusual in this neighborhood. Previous owners never altered the original floor plan and had not made any significant investment in the house since the 1960’s, when an owner added asbestos siding. The house was severely rundown, and the previous owner was a “pack rat”, which made the initial phase of the Net Zero project difficult

New Samarium and Neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field

Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near zero net magnetization with substitutions of 6 to 9 atomic percent of Nd and 25 atomic percent of Gd, respectively. The notion of magnetic compensation in them is also elucidated by the crossover of zero magnetization axis at low magnetic fields (less than 103 Oe) and field-induced reversal in the orientation of the magnetic moments of the dissimilar rare earth ions at higher magnetic fields. These magnetically ordered materials with no net magnetization and appreciable conduction electron polarization display an attribute of an exchange bias field, which can be tuned. The attractively high magnetic ordering temperatures of about 270 K, underscore the importance of these materials for potential applications in spintronics.Comment: 6 page text + 5 figure