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The Zambezi Riparian Region (ZRR) is a lifeline and home to ∼40 million people who depend heavily on the river basin for their livelihood. It also furnishes 8 of its riparian countries with goods and services on which hydropower production and food security anchor. The sustainability of the ZRR is threatened by extreme climate events. Here, we interrogate consecutive dry days (CDDs), an effective metric of extreme climatic events with implications on drought-driven water availability. We use ensemble empirical mode decomposition (EEMD) to understand CDDs. Results indicate that periodic characteristics of CDDs are generally few and mainly at the intra and interannual timescales. Further, the interannual variability of CDDs was found to exhibit a meridional pattern with increments propagating south-eastwards thus, areas in the south-eastern part of the ZRR (e.g. Northern Zimbabwe, Northern Mozambique, and the southern parts of Zambia) have a CDD stress disadvantage. These results suggest that the challenge of putting in place anticipatory actions should primarily focus on these fragile areas of the ZRR. Additionally, findings embodied herein provide climatic antecedent conditions for extreme events and the relevant information for long-term climate forecasts in the region. As such, these findings contribute to deepening our understanding of future risks associated with climate extremes thus, facilitating policy-making processes. • Inter and internannual timescales dominate changes in Consecutive dry days (CDDs) in the Zambezi Riparian Region (ZRR). • We also find that the south-eastern part of the ZRR has the strongest CDD stress disadvantage. • We recommend that the ZRR adopts a mechanism that anticipates CDDs and puts in place actions to cushion them. [ABSTRACT FROM AUTHOR]

Orthogonal frequency and code division multiplexing (OFCDM) which can be extended orthogonal frequency and code division multiple access (OFCDMA) has a good performance, because it can mitigate multi path interference while maintaining high data rate. Furthermore, cooperative OFCDM relaying system provides these advantages, and this system can effectively use the limited resource with respect to data rate and each terminal's energy efficiency. Therefore we proposed cooperative OFCDMA relaying uplink system because of the user's requirement of the high data rate at uplink. However, a throughput performance decreases when this system employs many relays in case of each relay allocated code channel to separate each relay's signal. Therefore, in this paper, we present that the proposed system combines cyclic delay diversity due to complement throughput performance problem. DF (Decode-and-Forward) is assumed in this paper. It is considered that the users which want to send data to BS only decode the data from other users. In addition to that, we propose the adaptive cooperative communication for the OFCDMA uplink system. The proposed adaptive system can easily select the cooperative relay. [ABSTRACT FROM AUTHOR]

This paper proposes a new hybrid cyclic delay diversity (HCDD) scheme for multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. Unlike the existing double space time transmit diversity (DSTTD) and stacked cyclic delay diversity (SCDD) schemes that are suitable for integer multiplexing rates, the proposed HCDD scheme can achieve arbitrary non-integer multiplexing rates. Our results demonstrate that the HCDD scheme can provide flexibility in selecting the required number of transmitting antennas and in adjusting diversity and multiplexing gains to match various users requirements. The advantages of the proposed HCDD, including the flexible rate assignment and less complex receivers, are presented in applications of scalable video broadcasting (SVB). [ABSTRACT FROM AUTHOR]

Cooperative spectrum sensing has emerged as a promising solution to the hidden terminal problem in cognitive radio networks (CRNs). It could significantly promote the sensing capability of CRNs by exploiting space diversity gains in a fading environment. However, owing to the decision reporting overhead, there exists a tradeoff between the system throughput and performance of cooperative spectrum sensing. In this paper, we propose a cyclostationarity-based decision reporting scheme for cooperative spectrum sensing in CRNs with cyclic delay diversity orthogonal frequency division multiplexing (CDD-OFDM). Decision information would be embedded into the CDD-OFDM signals in terms of cyclostationary signatures and shared among cognitive radio (CR) users along with data transmissions. As a result, satisfied system throughput could be achieved without additional spectral or temporal resources consumption when the number of cooperative users increases. Numerical results are presented to show the system throughput enhancement. [ABSTRACT FROM AUTHOR]

Abstract: The Black-Scholes model is a renowned pricing method for European options. Weather derivatives are a financial product at the convergence of the insurance and stock markets that are at the present of a high level of interest. This product can hedge and be a profitable investment at the same time, and can be used on its own or as part of a portfolio. In this paper we wish to analyze if and how the Black-Scholes model applies to Weather derivatives. [Copyright &y& Elsevier]

The treatment of the motor symptoms of Parkinson's disease (PD) is dependent on the use of dopamine replacement therapy in the form of l-dopa and dopamine agonist drugs. However, the development of dyskinesia (chorea, dystonia, athetosis) can become treatment limiting. The initiation of dyskinesia involves a priming process dependent on the presence of nigral dopaminergic cell loss leading to alterations in basal ganglia function that underlie the expression of involuntary movements following the administration of each drug dose. Once established, dyskinesia is difficult to control and it is even more difficult to reverse the priming process. Dyskinesia is more commonly induced by l-dopa than by dopamine agonist drugs. This has been associated with the short duration of l-dopa causing pulsatile stimulation of postsynaptic dopamine receptors compared to the longer acting dopamine agonists that cause more continuous stimulation. As a result, the concept of continuous dopaminergic stimulation (CDS) has arisen and has come to dominate the strategy for treatment of early PD. However, CDS has flaws that have led to the general acceptance that continuous drug delivery (CDD) is key to the successful treatment of PD. Studies in both experimental models of PD and in clinical trials have shown CDD to improve efficacy, but reduce dyskinesia induction, and to reverse established involuntary movements. Two key clinical strategies currently address the concept of CDD: (1) in early-, mid- and late-stage PD, transdermal administration of rotigotine provides 24 h of drug delivery; (2) in late-stage PD, the constant intraduodenal administration of l-dopa is utilized to improve control of motor symptoms and to diminish established dyskinesia. This review examines the rationale for CDD and explores the clinical benefit of using such a strategy for the treatment of patients with PD. [ABSTRACT FROM AUTHOR]

Abstract: In order to image the radiation field, instruments measure the position of interaction of the incident quanta, a task typically accomplished by partitioning the detector or its readout. We previously performed a fundamental investigation of the electrode design and pulse shape analysis routines required to optimize the detector''s position resolution, when limited by both temporal and carrier uncertainties. If the transmission-line electrode structure is balanced at the frequencies of interest, then the time difference between the pulses at the readout end of a serpentine delay-line electrode structure can be used to measure the position at which the charge was collected. In this paper, we describe the fabrication techniques used to overcome the two greatest limitations of the early detectors, namely, high leakage currents and high propagation losses. In the following, we describe, through both models and measurements, the means by which: (a) one can achieve impedance matching by conversion of the electrode into a 50Ω asymmetric strip line and (b) one can minimize the propagation losses by the use of thick high-conductivity electrodes and the use of low-loss dielectrics (BaSrTiO3 and BaTiO3), as a part of an asymmetric strip line design. In order to accomplish low leakage designs, we describe the fabrication of delay-line PIN devices with metal field plates (MFPs) and multiple floating guard rings. [Copyright &y& Elsevier]

Abstract: Activated carbons (ACs) having hydrogen storage performances among the highest reported so far (i.e. 6.6 wt. % at 77 K and 4 MPa) are presented. These materials were prepared by chemical activation of anthracite with KOH. The effects of two experimental parameters: KOH/anthracite weight ratio (W) and activation temperature (T), on the hydrogen storage capacity were studied by application of central composite design and response surface methodology. A quadratic model was developed for correlating W and T to the hydrogen storage capacity. The analysis of variance showed that W the only significant parameter in the range of the experimental conditions tested. Our optimized AC showed higher hydrogen capacity in terms of absolute and excess storage properties than the well-known MAXSORB-3. [Copyright &y& Elsevier]

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The classical sine-Gordon model is a two-dimensional integrable field theory, with particle-like solutions - the so-called solitons. Using its integrability one can define the quantum theory without the process of canonical quantization. The bootstrap method employs the fundamental properties of the model to restrict the structure of the scattering matrix as far as possible. The classical model can be extended with integrable discontinuities, purely transmitting jump defects. Then the quantum version of the extended model can be determined via the bootstrap method again. The resulting quantum theory contains the so-called CDD uncertainty. The aim of this article is to carry out the semiclassical approximation on both the classical and the quantum side of the defect sine-Gordon theory. The CDD ambiguity can be restricted by comparing the two results. To complete the comparison we have to calculate the relation between the classical and quantum parameters. We determine the quantum parameters from the poles of the T matrix, and we find that there are resonances in the spectrum. [ABSTRACT FROM AUTHOR]

The developing cardiovascular system is a sensitive target of many environmental pollutants, including dioxins, dioxin-like polychlorinated biphenyls (PCBs), and some pesticides such as methyl parathion. Laboratory research has utilized a variety of vertebrate models to elucidate potential mechanisms that mediate this cardioteratogenicity and to establish the sensitivity of different species for predicting potential risk to environmental and human health. Studies of dioxin and dioxin-like PCBs have illustrated that piscine, avian, and mammalian embryos exhibit cardiovascular structural changes and functional deficits, although the specific characteristics vary among the individual models. Piscine models typically exhibit reduced blood flow, altered heart looping, and reduced heart size and contraction rate. The chick embryo exhibits extensive cardiac dilation, thinner ventricle walls, and reduced responsiveness to chronotropic stimuli, while the murine embryo exhibits reduced heart size. It is notable that in all models the dioxin-associated cardioteratogenicity is associated with increases in cardiovascular apoptosis and decreases in cardiocyte proliferation. While the cardiotertogenicity in piscine and avian species is associated with overt morbidity and mortality, that is not the case for the murine embryo. However, murine offspring exposed during development to dioxin exhibit cardiac hypertrophy and an increased sensitivity to a second cardiovascular insult in adulthood. Thus, although the mammalian embryo is less sensitive to cardiovascular defects by dioxin and dioxin-like compounds, developmental exposure increases the risk of cardiovascular disease later in life. The impact of developmental exposure to dioxin-like chemicals on human cardiovascular disease susceptibility is not known. However, recent animal research has confirmed human epidemiology studies that dioxin exposure in adulthood is associated with hypertension and cardiovascular disease. [ABSTRACT FROM AUTHOR]

Many examples of natural noise show common amplitude modulations at different frequency regions. This kind of noise has been termed comodulated noise and is widely examined in hearing research, where an enhanced detectability of pure tones and narrow noise bands in comodulated noise compared to unmodulated noise is well known as the CMR or CDD effects, respectively. Here it is shown that only one signal processing step, a compressive nonlinearity motivated by the peripheral auditory system, is sufficient to explain a considerable contribution to these effects. Using an analytical approach, the influence of compression on the detectability of periodic and narrow band signals in the presence of unmodulated and comodulated noise is investigated. This theoretical treatment allows for identifying the mechanism leading to improved signal detection. The compressive nonlinearity constitutes an adaptive gain which selectively boosts a stimulus during time spans of inherently increased signal-to-noise ratio and attenuates it during time spans dominated by noise. On average, these time spans are more pronounced in stimuli with comodulated noise than with unmodulated noise, thus giving rise to the observed CMR and CDD effects. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of the Cyclic Delay Diversity (CDD) transmit diversity scheme on DYB-H networks. Transmit diversity improves reception and Quality of Service (QoS) in areas of poor coverage such as sparsely populated or obscured locations. The technique not only provides robust reception in mobile environments thus improving QoS, but it also reduces network costs in terms of the transmit power, number of infrastructure elements, antenna height and the frequency reuse factor over indoor and outdoor environments. In this paper, the benefit and effectiveness of CDD transmit diversity is tackled through simulation results for comparison in several scenarios of coverage in DVB-H networks. The channel model used in the simulations is based on COST207 and a basic radio planning technique is used to illustrate the main principles developed in this paper. The work reported in this paper was supported by the European Commission IST project-PLUTO (Physical Layer DVB Transmission Optimization). [ABSTRACT FROM AUTHOR]

The objective of this paper is to investigate different diversity techniques for broadcast networks that will minimize the complexity and improve received SNR of broadcast systems. Resultant digital broadcast networks would require fewer transmitter sites and thus be more cost-effective and have less environmental impact. The techniques can be applied to DVB-T, DVB-H and DAB systems that use Orthogonal Frequency Division Multplexing (OFDM). These are key radio broadcast network technologies, which are expected to complement emerging technologies such as WiMAX and future 4G networks for delivery of broadband content. Transmitter and receiver diversity technologies can increase the frequency and time selectivity of the resulting channel transfer function at the receiver. Diversity exploits the statistical nature of fading due to multipath and reduces the likelihood of deep fading by providing a diversity of transmission signals. Multiple signals are transmitted in such a way as to ensure that several signals reach the receiver each with uncorrelated fading. Transmit diversity is more practical than receive diversity due to the difficulty of locating two receive antennas far enough apart in a small mobile device. The schemes examined here comply with existing DVB standards and can be incorporated into existing systems without change. The diversity techniques introduced in this paper are applied to the DVB-H system. Bit error performance investigations were conducted by simulation for different DVB-H and diversity parameters. [ABSTRACT FROM AUTHOR]

Spatial diversity techniques will inarguably play an important role in the realization of B3G wireless systems, which promise higher data transmission rates and affluent multi-media contents. In this article, we present a CDD based "space time/space-frequency (ST/SF) block coded" diversity transmitter for MC-CDMA system. Equipped with CDD a fraction of the total number of transmit antennas is used to extract the frequency (multipath) diversity while the remaining antennas employing ST/SF-block codes provide maximum spatial diversity. This hybrid architecture makes full use of the frequency domain spreading of MC-CDMA system and provides excellent spatial and frequency diversity which is otherwise impossible to realize with standalone CDD or block codes [ABSTRACT FROM PUBLISHER]

Abstract: High resolution infrared emission spectra of ZnH, ZnD, CdH, and CdD have been recorded with a Fourier transform spectrometer. The v =1→0 and v =2→1 bands of ZnH, ZnD, CdH, and CdD, as well as the v =3→2 band of ZnD were observed for the X 2Σ+ ground electronic state. In addition, new rotational spectra have been recorded for CdH and CdD using a tunable far-infrared spectrometer, and pure rotational transitions in the v =1 level of the ground state were measured. The new data were combined with the previous data from diode laser infrared spectra and pure rotation spectra of ZnH/ZnD and CdH/CdD available in the literature. The data from all isotopologues were fitted together using a Dunham-type energy level expression for 2Σ+ states, and Born–Oppenheimer breakdown correction parameters were obtained. The equilibrium rotational constants (B e) of 64ZnH, 64ZnD, 114CdH, and 114CdD were determined to be 6.691332(17), 3.402156(7), 5.447074(18), and 2.750761(6)cm−1, respectively, and the associated equilibrium internuclear distances (r e) are 1.593478(2), 1.593001(2), 1.760098(3), and 1.759695(2)Å, respectively. Simple reduced mass scaling for the spin–rotation interaction constants of ZnH and CdH fully accounted for their isotopologue dependence, and no Born–Oppenheimer breakdown correction was required for these parameters. [Copyright &y& Elsevier]

Dibenzofuran (DF) is formed from phenol and benzene in combustion gas exhaust streams prior to particle collection equipment. Subsequent chlorination at lower temperatures on particle surfaces is a potential source of chlorinated dibenzofuran (CDF). Gas streams containing 8% O2 and approximately 0.1% DF vapor were passed through particle beds containing copper (II) chloride (0.5% Cu, mass) at temperatures ranging from 200 to 400 °C to investigate the potential for CDF formation during particle collection. Experiment duration was sufficient to provide an excess amount of DF (DF/Cu=3). The efficiency of DF chlorination by CuCl2 and the distribution of CDF products were measured, with effects of temperature, gas velocity, and experiment duration assessed. Results of a more limited investigation of dibenzo-p-dioxin (DD) chlorination by CuCl2 to form chlorinated DD (CDD) products are also presented.The efficiency of DF/DD chlorination by CuCl2 was high, both in terms of CuCl2 utilization and DF/DD conversion. Total yields of Cl on CDF/CDD products of up to 0.5 mole Cl per mole CuCl2 were observed between 200 and 300 °C; this suggests that nearly 100% CuCl2 was utilized, assuming a conversion of two moles of CuCl2 to CuCl per mole Cl added to DD/DF. In a short duration experiment (DF/Cu=0.3), nearly 100% DF adsorption and conversion to CDF was achieved. The degree of CDF chlorination was strongly dependent on gas velocity. At high gas velocity, corresponding to a gas–particle contact time of 0.3 s, mono-CDF (MCDF) yield was largest, with yields decreasing with increasing CDF chlorination. At low gas velocity, corresponding to a gas–particle contact time of 5 s, octa-CDF yield was largest. DF/DD chlorination was strongly favored at lateral sites, with the predominant CDF/CDD isomers within each homologue group those containing Cl substituents at only the 2,3,7,8 positions. At the higher temperatures and lower gas velocities studied, however, broader isomer distributions, particularly of the less CDD/CDF products, were observed, likely due to preferential destruction of the 2,3,7,8 congeners. [Copyright &y& Elsevier]

A 565 bp DNA stretch coding for the Bacillus caldolyticus DSM405 cdd gene was cloned by PCR amplification and sequenced. Nucleotide sequence analysis to the cloned DNA stretch revealed an open reading frame of 396 bp encoding a deduced polypeptide of 132 amino acids with a molecular mass of 14,235 Da. Comparison of the deduced polypeptide of the B. caldolyticus cdd gene to that of the Bacillus subtilis cdd showed a 71% sequence homology. Thermostable cytidine deaminase expressed in Escherichia coli JF611/pCJH53 was purified through rapid procedures consisting of anionic-exchange column chromatography and FPLC. Finally purified enzyme showed 167.5 u/mg of specific activity, corresponding to about 94-fold purification with respect to the crude extract. Molecular mass of the monomer was estimated to be about 14-kDa by SDS-polyacrylamide gel electrophoresis (PAGE), and tetrameric configuration of the native enzyme was supposed by gel filteration. Optimal deamination occurred at 70∼75°C and pH 7.5–8.0, and the activity was inhibited by Fe2+, Cu2+, Hg2+, and p-chloromercuribenzoic acid (pCMB). The enzyme was thermostable and the apparent Km and Vmax values for the cytidine were 2.1 × 10−3 M and 36.4 mM min−1mg−1, respectively. [Copyright &y& Elsevier]

To decrease the costs of producing the anti-HIV drug, lamivudine, an enzymatic conversion process was developed instead of the traditional chemical method. Thermostable cytidine deaminase was over-produced by cloning the cdd gene into E. coli JF611/pCJH53 from Bacillus caldolyticus. The purified cytidine deaminase was recovered from the lysate of the recombinant E. coli JF611/pCJH53 by removing heat-denatured proteins and eluting sequential chromatography. When the enzyme was used to deaminate (-)-β-l-(2R,5S)- and (+)-β-d-(2S,5R)-1,3-oxathiolanyl-cytosine, about 68% of the (+)-β-d-(2S,5R)-1,3-oxathiolanyl-cytosine was deaminated into the corresponding (+)-thiauridine maximally. [ABSTRACT FROM AUTHOR]

The toxicity in humans of 2,3,7,8-tetrachlorodibenzo-p-dioxin, a man-made compound and environmental pollutant, is still debated. The industrial accident at Seveso, Italy, in 1976 exposed a large population of both sexes and of all ages to a massive concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Monitoring of soil and measurement of blood samples allowed classification of the exposed population into three categories: A, B and R (high, medium and low exposure, respectively). This article presents data from longitudinal health monitoring of the population, including liver function, immune function, neurological impairment, dermatological effects, reproductive pathology, and mortality. [ABSTRACT FROM AUTHOR]

[Display omitted] • The TPA of those PAHs comes from the local excitation. • The increase of conjugate effect of π bridge reduces the TPA cross-section. • The CTM was first applied to analysis the ICT mechanism in TPA processes. • The contribution of π bridge to molecular NLO properties were analyzed. The influences of the conjugation effect on the charge transfer and nonlinear optical (NLO) properties of polycyclic aromatic hydrocarbons (PAHs) are comprehensively investigated at the microscopic molecular level. We found that the conjugation effect of π bridge is negatively correlated with molecular planarity, excitation energy, two-photon absorption (TPA) cross-section, and the second hyperpolarizability. For the first time, the charge transfer matrix (CTM) is applied to the molecular two-photon transition process. Combining the charge difference density (CDD) diagram with CTM heat map to visually quantitative investigate the characteristics of excited states, the charge transfer path and transfer amount between atoms. During the two-photon transition of all molecules, the electronic excited state is locally excited. Compared with the first process, the range of intramolecular charge transfer in the second process of the two-photon transition is expanded. Comprehensive results prove that the π bridge with large conjugation effect distorts the molecular structure, which is not conducive to the intramolecular charge transfer. Therefore, the molecule DBP-1 with a carbon–carbon double bond as the π bridge has the largest transition dipole moments, TPA cross-section, and second static hyperpolarizability. Our research method can provide effective guidance for the design and optimization of nonlinear organic conjugated molecular materials. [ABSTRACT FROM AUTHOR]

One simple way to estimate the relationship between air temperature and the energy needed for heating and cooling is to use the concept of degree day. Cooling degree days (CDD) and heating degree days (HDD) are indicators of the energy required to reach comfort levels and are related directly to energy demands. Therefore, using a novel approach, we examine the current conditions and future projections in degree days over Mexico using observations (Livneh and CPC), ERA5 reanalysis, and simulations from the Regional Climate Model (RegCM4). The RegCM4 experiments were driven by different General Circulation Models for two Representative Concentration Pathways scenarios. We consider three 20-year periods as "present conditions" (1995–2014), "near-future conditions" (2041–2060), and "far-future conditions" (2080–2099). The results suggest that in the future, under the lowest radiative forcing scenario there will be a smaller increase (decrease) in CDD (HDD) for the far-future, as compared to the near-future. This could represent the model's response to the peak of radiative forcing at mid-century and its subsequent decline. For the highest radiative forcing scenario, we found a greater increase (decrease) in CDD (HDD) for the far-future, which could be explained by the response of the RegCM4 to the warming increase projected for 2100. [ABSTRACT FROM AUTHOR]

The intensity and duration of hot weather and the number of extreme weather events, such as heatwaves, are increasing, leading to a growing need for space cooling energy demand. Together with the building stock's low energy performance, this phenomenon may also increase households' energy consumption. On the other hand, the low level of ownership of cooling equipment can cause low energy consumption, leading to a lack of indoor thermal comfort and several health-related problems, yet increasing the risk of energy poverty in summer. Understanding future temperature variations and the associated impacts on building cooling demand will allow mitigating future issues related to a warmer climate. In this respect, this paper analyses the effects of change in temperatures in the residential sector cooling demand in 2050 for a case study of nineteen cities across seven countries: Cyprus, Finland, Greece, Israel, Portugal, Slovakia, and Spain, by estimating cooling degree days and hours (CDD and CDH). CDD and CDH are calculated using both fixed and adaptive thermal comfort temperature thresholds for 2020 and 2050, understanding their strengths and weaknesses to assess the effects of warmer temperatures. Results suggest a noticeable average increase in CDD and CDH values, up to double, by using both thresholds for 2050, with a particular interest in northern countries where structural modifications in the building stock and occupants' behavior should be anticipated. Furthermore, the use of the adaptive thermal comfort threshold shows that the projected temperature increases for 2050 might affect people's capability to adapt their comfort band (i.e., indoor habitability) as temperatures would be higher than the maximum admissible values for people's comfort and health. [ABSTRACT FROM AUTHOR]