Partial nutrient balances from agronomic and economic viewpoints: the case of corn cultivation in the acid upland soils of Isabela, the Philippines

Soil propertiesMaizeEconomic aspects

Formulation of the Spinor Field in the Presence of a Minimal Length Based on the Quesne-Tkachuk Algebra

In 2006 Quesne and Tkachuk (J. Phys. A: Math. Gen. {\bf 39}, 10909, 2006) introduced a (D+1)-dimensional $(\beta,\beta')$-two-parameter Lorentz-covariant deformed algebra which leads to a nonzero minimal length. In this work, the Lagrangian formulation of the spinor field in a (3+1)-dimensional space-time described by Quesne-Tkachuk Lorentz-covariant deformed algebra is studied in the case where $\beta'=2\beta$ up to first order over deformation parameter $\beta$. It is shown that the modified Dirac equation which contains higher order derivative of the wave function describes two massive particles with different masses. We show that physically acceptable mass states can only exist for $\beta<\frac{1}{8m^{2}c^{2}}$. Applying the condition $\beta<\frac{1}{8m^{2}c^{2}}$ to an electron, the upper bound for the isotropic minimal length becomes about $3 \times 10^{-13}m$. This value is near to the reduced Compton wavelength of the electron $(\lambda_c = \frac{\hbar}{m_{e}c} = 3.86\times 10^{-13} m)$ and is not incompatible with the results obtained for the minimal length in previous investigations.Comment: 11 pages, no figur

Vulnerability to social engineering in social networks : a proposed user-centric framework

Social networking sites have billions of users who communicate and share their personal information every day. Social engineering is considered one of the biggest threats to information security nowadays. Social engineering is an attacker technique to manipulate and deceive users in order to access or gain privileged information. Such attacks are continuously developed to deceive a high number of potential victims. The number of social engineering attacks has risen dramatically in the past few years, causing unpleasant damage both to organizations and individuals. Yet little research has discussed social engineering in the virtual environments of social networks. One approach to counter these exploits is through research that aims to understand why people fall victim to such attacks. Previous social engineering and deception research have not satisfactory identified the factors that influence the users' ability to detect attacks Characteristics that influence users' vulnerability must be investigated to address this issue and help to build a profile for vulnerable users in order to focus on increasing the training programs and education for those users. In this context, the present study proposes a user-centric framework to understand the user's susceptibility, relevant factors and dimensions

Cardioplegia at subnormothermia facilitates rapid functional resuscitation of hearts preserved in SOMAH for transplants

Objectives: Hearts preserved ex vivo at 4°C undergo time-dependent irreversible injury due to extreme hypothermia. Studies using novel organ preservative solution SOMAH, suggest that hearts are optimally ‘preserved’ at subnormothermic temperature of 21°C. Present study evaluates relative efficacy of SOMAH ‘cardioplegia’ at 4 and 21°C in preservation of optimum heart function after in vitro storage at subnormothermia. Methods: Porcine hearts arrested with SOMAH cardioplegia at 4 or 21°C were stored in SOMAH for 5-hour at 21°C (n = 5). At the end of storage, the weight of hearts was recorded and biopsies taken for cardiac tissue high energy phosphate level measurements. The hearts were then attached to a reperfusion apparatus and biochemical parameters including cardiac enzyme release and myocardial oxygen consumption and lactate production were determined in perfusate samples at regular intervals during ex vivo perfusion experiment. Functional evaluation of the hearts intraoperatively and ex vivo was performed by 2D echocardiography using trans-esophageal echocardiography probe. Results: Post-storage heart weights were unaltered in both groups, while available high-energy phosphates (HEP) were greater in the 21°C group. Upon ex vivo reperfusion, coronary flow was significantly greater (p < 0.05) in 21°C group. 2D echo revealed a greater cardiac output, fractional area change and ejection fraction in 21°C group that was not significantly different than the 4°C group. However, unlike 4°C hearts, 21°C hearts did not require inotropic intervention. Upon reperfusion, rate of cardiac enzyme release temporally resolved in 21°C group, but not in the 4°C group. 21°C working hearts maintained their energy state during the experimental duration but not the 4°C group; albeit, both groups demonstrated robust metabolism and function during this period. Conclusions: Rapid metabolic switch, increased synthesis of HEP, decreased injury and optimal function provides evidence that hearts arrested at 21°C remain viably and functionally superior to those arrested at 4°C when stored in SOMAH at ambient temperature pre-transplant. Ultramini-abstract Cardioplegic arrest and preservation of hearts in SOMAH at ambient temperature efficiently conserves metabolism and function in in vitro porcine model of heart transplant. Electronic supplementary material The online version of this article (doi:10.1186/s13019-014-0155-z) contains supplementary material, which is available to authorized users

Postmenopausal Women With Greater Paracardial Fat Have More Coronary Artery Calcification Than Premenopausal Women: The Study of Women's Health Across the Nation (SWAN) Cardiovascular Fat Ancillary Study.

BackgroundVolumes of paracardial adipose tissue (PAT) and epicardial adipose tissue (EAT) are greater after menopause. Interestingly, PAT but not EAT is associated with estradiol decline, suggesting a potential role of menopause in PAT accumulation. We assessed whether volumes of heart fat depot (EAT and PAT) were associated with coronary artery calcification (CAC) in women at midlife and whether these associations were modified by menopausal status and estradiol levels.Methods and resultsEAT and PAT volumes and CAC were measured using electron beam computed tomography scans. CAC was evaluated as (1) the presence of CAC (CAC Agatston score ≥10) and (2) the extent of any CAC (log CAC Agatston score &gt;0). The study included 478 women aged 50.9&nbsp;years (58% pre- or early perimenopausal, 10% late perimenopausal, and 32% postmenopausal). EAT was significantly associated with CAC measures, and these associations were not modified by menopausal status or estradiol. In contrast, associations between PAT and CAC measures were modified by menopausal status (interaction-P≤0.01). Independent of study covariates including other adiposity measures, each 1-SD unit increase in log PAT was associated with 102% higher risk of CAC presence (P=0.04) and an 80% increase in CAC extent (P=0.008) in postmenopausal women compared with pre- or early perimenopausal women. Additional adjustment for estradiol and hormone therapy attenuated these differences. Moreover, the association between PAT and CAC extent was stronger in women with lower estradiol levels (interaction P=0.004).ConclusionsThe findings suggest that PAT is a potential menopause-specific coronary artery disease risk marker, supporting the need to monitor and target this fat depot for intervention in women at midlife

Testing general relativity with accretion onto compact objects

The X-ray emission of neutron stars and black holes presents a rich phenomenology that can lead us to a better understanding of their nature and to address more general physics questions: Does general relativity apply in the strong gravity regime? Is spacetime around black holes described by the Kerr metric? This white paper considers how we can investigate these questions by studying reverberation mapping and quasi-periodic oscillations in accreting systems with a combination of high-spectral and high-timing resolution. In the near future, we will be able to study compact objects in the X-rays in a new way: advancements in transition-edge sensors (TES) technology will allow for electron-volt-resolution spectroscopy combined with nanoseconds-precision timing.Comment: White paper submitted for Astro2020 Decadal Survey. 8 pages, 2 figure

Increase in wheat production through management of abiotic stresses : A review

About 9% of area on earth is under crops out of which 91% is under various stresses. On an average, about 50% yield losses are due to abiotic stresses mostly due to high temperature (20%), low temperature (7%), salinity (10%), drought (9%) and other abiotic stresses (4%). As there is no scope for increasing area under agriculture, the increased productivity from these stressed land is a must to meet the ever increasing demand. Further, the severity of abiotic stresses is likely to increase due to changing climate leading to adverse effect on crops. Therefore, abiotic stresses like drought, salinity, sodicity, acidity, water logging, heat, nutrient toxicities/ deficiencies etc need to be effectively addressed through adoption of management practices like tillage and planting options, residue management, sowing time, stress tolerant cultivars, irrigation scheduling and integrated nutrient management to conserve natural resources, mitigating their adverse effect and sustainable wheat production

Hidden dimers and the matrix maps: Fibonacci chains re-visited

The existence of cycles of the matrix maps in Fibonacci class of lattices is well established. We show that such cycles are intimately connected with the presence of interesting positional correlations among the constituent `atoms' in a one dimensional quasiperiodic lattice. We particularly address the transfer model of the classic golden mean Fibonacci chain where a six cycle of the full matrix map exists at the centre of the spectrum [Kohmoto et al, Phys. Rev. B 35, 1020 (1987)], and for which no simple physical picture has so far been provided, to the best of our knowledge. In addition, we show that our prescription leads to a determination of other energy values for a mixed model of the Fibonacci chain, for which the full matrix map may have similar cyclic behaviour. Apart from the standard transfer-model of a golden mean Fibonacci chain, we address a variant of it and the silver mean lattice, where the existence of four cycles of the matrix map is already known to exist. The underlying positional correlations for all such cases are discussed in details.Comment: 14 pages, 2 figures. Submitted to Physical Review