Breeding climate change resilient maize and wheat for food security

Climate change is affecting agriculture directly or indirectly, worldwide and is an important challenge that threatens the long-term production growth of cereals. Fluctuating temperature, green-house gases, rainfall, and high humidity directly affect the crops, pathogens, insects, and weeds. Several new diseases, weeds, and insect pests have started appearing with the changing climate. Maize and wheat are the two of the most important food crops worldwide with too are getting affected. Predictions suggest that climate change will reduce maize and wheat production this will coincide with a substantial increase in demand for maize and wheat due to rising populations. Maize and wheat research has a crucial role to play in enhancing adaptation to and mitigation of climate change while also enhancing food security. The varieties of agricultural crops with increased tolerance to heat and drought stress and resistance to pests and diseases are serious for handling existing climatic variability and for adaptation to progressive climate change. Numerous climate resilient agricultural technologies such as zero tillage (no tillage), laser land leveling, happy seeder, raised-bed planting, tensiometer, and rotavator have been invented for the conservation of agricul-ture. Further, drip irrigation and fertigation, leaf color chart (LCC) for need-based application of nitrogen, integrated nutrient management (INM) systems, integrated pest management (IPM) systems, integrated disease management (IDM) systems, site-specific management systems using remote sensing, GPS, and GIS, and Web-based decision support systems for controlling diseases and insect pests are being commercialized to mitigate the climate change

History and epidemiology of foot-and-mouth disease in Afghanistan: A retrospective study

Background Foot and mouth disease (FMD) is endemic in Afghanistan with serotypes O, A and Asia 1 being prevalent. A retrospective study of data collected through passive surveillance of outbreaks of FMD in Afghanistan from 1995 to 2016 was undertaken to determine the temporal and spatial distribution of FMD in the country. Results A total of 4171 outbreaks were reported between 1995 and 2008 with a strong correlation between the number of outbreaks and the number of provinces (r = 0.85, s = 68.2, p < 0.001); and between the number of outbreaks and the number of districts containing infected animals (r = 0.68, s = 147.8, p = 0.008). Of 7558 samples collected from livestock originating from 34 provinces in 2009, 2011 and 2013–2015, 54.1% were test positive (FMDV 3ABC-trapping ELISA) and the prevalence varied significantly between years (χ2 = 263.98, df = 4, P < 0.001). Clinically suspected cases were reported in 2016 with a substantial positive correlation (r = 0.70, P < 0.001) between the number of districts with cases and the number of reported cases. Serotype O was the predominant serotype detected during the study period, although serotypes A and Asia1 were also detected. Cattle were involved in all outbreaks in the study period and infections were detected in all years of the study in Hirat province in the north-west (bordering Iran), Nangarhar province in the east (bordering Pakistan) and Kabul province in the centre of the country. Conclusions The current paper was the first analysis of existing data focusing on the spatiotemporal distribution of FMD in Afghanistan. The findings from this study provide valuable direction for further research to understand the epidemiology of FMD and its control in Afghanistan

Signatures of Viber Security Traffic

Viber is one of the widely used mobile chat application which has over 606 million users on its platform. Since the recent release of Viber 6.0 in March/April 2016 and its further updates, Viber provides end-to-end encryption based on Open Whisper Signal security architecture. With proprietary communication protocol scattered on distributed cluster of servers in different countries and secure cryptographic primitives, Viber offers a difficult paradigm of traffic analysis. In this paper, we present a novel methodology of identification of Viber traffic over the network and established a model which can classify its services of audio and audio/video calls, message chats including text and voice chats, group messages and file/media sharing. Absolute detection of both parties of Viber voice and video calls is also demonstrated in our work. Our findings on Viber traffic signatures are applicable to most recent version of Viber 6.2.2 for android and iOS devices

Quantum-to-classical Transition of Cosmological Perturbations for Non-vacuum Initial States

Transition from quantum to semiclassical behaviour and loss of quantum coherence for inhomogeneous perturbations generated from a non-vacuum initial state in the early Universe is considered in the Heisenberg and the Schr\"odinger representations, as well as using the Wigner function. We show explicitly that these three approaches lead to the same prediction in the limit of large squeezing (i.e. when the squeezing parameter $|r_k|\to \infty$): each two-modes quantum state (k, -k) of these perturbations is equivalent to a classical perturbation that has a stochastic amplitude, obeying a non-gaussian statistics which depends on the initial state, and that belongs to the quasi-isotropic mode (i.e. it possesses a fixed phase). The Wigner function is not everywhere positive for any finite $r_k$, hence its interpretation as a classical distribution function in phase space is impossible without some coarse graining procedure. However, this does not affect the transition to semiclassical behaviour since the Wigner function becomes concentrated near a classical trajectory in phase space when $|r_k|\to \infty$ even without coarse graining. Deviations of the statistics of the perturbations in real space from a Gaussian one lie below the cosmic variance level for the N-particles initial states with N=N(|k|) but may be observable for other initial states without statistical isotropy or with correlations between different k modes. As a way to look for this effect, it is proposed to measure the kurtosis of the angular fluctuations of the cosmic microwave background temperature.Comment: LaTeX (28 pages),+2 eps figure

Assessment of crop raiding activities of wild animal species in Kainji Lake National Park, Nigeria

The study focused on the assessment of crop raiding activities in some communities around Zugurma sector of Kainji Lake National Park, Nigeria. The study identify the species of wild animals that raid farms, farm produce that were affected in the area, seasons such activities occurred and level of destruction to farm products in the study area. Two hundred questionnaires were administered purposely to some farmers in the support zones communities with close proximity with to park boundaries and only one hundred and seventy four questionnaires were retrieved. The communities sampled were Felegi, Shafinni, Babugi, Fanga, and Ibbi. Direct observation and personal interview using an interpreter was employed to source for information. Data collected were analyzed using descriptive statistics. The findings from this study revealed that Primates (Erythrocebus patas and Chlorocebus aethiops tantalus) had the highest percentage of raid in farm with (44.7%) while Ground Squirrel (Xerus erythopus), Western Hartebeest (Alcelaphus buselaphus), Grimm’s Duiker (Sylvicapra grimmia) and Bushbuck (Tragelaphus scriptus) were the least raiders with (3.3%) respectively. This study also revealed that maize (zea mays) is the mostly raided crop with (19.1%) while cassava (Manihot esculentus) was the least with (2.5%). It was observed that crop raiding activities occur all year round with (43.7%) while less activity occur during the dry season with (27.6%) due to the fact that most crops had been harvested. The level of destruction caused by wild animals is very high with (94.3%) respondents attesting to this fact. The study shows that raiding activities affect farmlands that are very close to park boundaries more therefore, it is advisable for farmers to site their farmland far from park boundaries or cultivate crops that may not be destroyed by wild animals when they farm close to park boundaries.Keywords: Assessment, Crop Raiding, Primates, Protected Areas, Respondent

Energy-Momentum Tensor of Cosmological Fluctuations during Inflation

We study the renormalized energy-momentum tensor (EMT) of cosmological scalar fluctuations during the slow-rollover regime for chaotic inflation with a quadratic potential and find that it is characterized by a negative energy density which grows during slow-rollover. We also approach the back-reaction problem as a second-order calculation in perturbation theory finding no evidence that the back-reaction of cosmological fluctuations is a gauge artifact. In agreement with the results on the EMT, the average expansion rate is decreased by the back-reaction of cosmological fluctuations.Comment: 19 pages, no figures.An appendix and references added, conclusions unchanged, version accepted for publication in PR

Improved Estimates of Cosmological Perturbations

We recently derived exact solutions for the scalar, vector and tensor mode functions of a single, minimally coupled scalar plus gravity in an arbitrary homogeneous and isotropic background. These solutions are applied to obtain improved estimates for the primordial scalar and tensor power spectra of anisotropies in the cosmic microwave background.Comment: 31 pages, 4 figures, LaTeX 2epsilon, this version corrects an embarrasing mistake (in the published version) for the parameter q_C. Affected eqns are 105, 109-110, 124, 148-153 and 155-15

Vacuum fluctuations and topological Casimir effect in Friedmann-Robertson-Walker cosmologies with compact dimensions

We investigate the Wightman function, the vacuum expectation values of the field squared and the energy-momentum tensor for a massless scalar field with general curvature coupling parameter in spatially flat Friedmann-Robertson-Walker universes with an arbitrary number of toroidally compactified dimensions. The topological parts in the expectation values are explicitly extracted and in this way the renormalization is reduced to that for the model with trivial topology. In the limit when the comoving lengths of the compact dimensions are very short compared to the Hubble length, the topological parts coincide with those for a conformal coupling and they are related to the corresponding quantities in the flat spacetime by standard conformal transformation. In the opposite limit of large comoving lengths of the compact dimensions, in dependence of the curvature coupling parameter, two regimes are realized with monotonic or oscillatory behavior of the vacuum expectation values. In the monotonic regime and for nonconformally and nonminimally coupled fields the vacuum stresses are isotropic and the equation of state for the topological parts in the energy density and pressures is of barotropic type. In the oscillatory regime, the amplitude of the oscillations for the topological part in the expectation value of the field squared can be either decreasing or increasing with time, whereas for the energy-momentum tensor the oscillations are damping.Comment: 20 pages, 2 figure

The Inflaton and Time in the Matter-Gravity System

The emergence of time in the matter-gravity system is addressed within the context of the inflationary paradigm. A quantum minisuperspace-homogeneous minimally coupled inflaton system is studied with suitable initial conditions leading to inflation and the system is approximately solved in the limit for large scale factor. Subsequently normal matter (either non homogeneous inflaton modes or lighter matter) is introduced as a perturbation and it is seen that its presence requires the coarse averaging of a gravitational wave function (which oscillates at trans-Planckian frequencies) having suitable initial conditions. Such a wave function, which is common for all types of normal matter, is associated with a ``time density'' in the sense that its modulus is related to the amount of time spent in a given interval (or the rate of flow of time). One is then finally led to an effective evolution equation (Schroedinger Schwinger-Tomonaga) for ``normal'' matter. An analogy with the emergence of a temperature in statistical mechanics is also pointed out.Comment: 14 pages, late

The multi-stream flows and the dynamics of the cosmic web

A new numerical technique to identify the cosmic web is proposed. It is based on locating multi-stream flows, i.e. the places where the velocity field is multi-valued. The method is local in Eulerian space, simple and computaionally efficient. This technique uses the velocities of particles and thus takes into account the dynamical information. This is in contrast with the majority of standard methods that use the coordinates of particles only. Two quantities are computed in every mesh cell: the mean and variance of the velocity field. In the cells where the velocity is single-valued the variance must be equal to zero exactly, therefore the cells with non-zero variance are identified as multi-stream flows. The technique has been tested in a N-body simulation of the \L CDM model. The preliminary analysis has shown that numerical noise does not pose a significant problem. The web identified by the new method has been compared with the web identified by the standard technique using only the particle coordinates. The comparison has shown overall similarity of two webs as expected, however they by no means are identical. For example, the isocontours of the corresponding fields have significantly different shapes and some density peaks of similar heights exhibit significant differences in the velocity variance and vice versa. This suggest that the density and velocity variance have a significant degree of independence. The shape of the two-dimensional pdf of density and velocity variance confirms this proposition. Thus, we conclude that the dynamical information probed by this technique introduces an additional dimension into analysis of the web.Comment: 19 pages, 10 figure