Rate of photosynthetic induction in fluctuating light varies widely among genotypes of wheat.

Crop photosynthesis and yield are limited by slow photosynthetic induction in sunflecks. We quantified variation in induction kinetics across diverse genotypes of wheat for the first time. Following a preliminary study that hinted at wide variation in induction kinetics across 58 genotypes, we grew 10 genotypes with contrasting responses in a controlled environment and quantified induction kinetics of carboxylation capacity (Vcmax) from dynamic A versus ci curves after a shift from low to high light (from 50 µmol m-2 s-1 to 1500 µmol m-2 s-1), in five flag leaves per genotype. Within-genotype median time for 95% induction (t95) of Vcmax varied 1.8-fold, from 5.2 min to 9.5 min. Our simulations suggest that non-instantaneous induction reduces daily net carbon gain by up to 15%, and that breeding to speed up Vcmax induction in the slowest of our 10 genotypes to match that in the fastest genotype could increase daily net carbon gain by up to 3.4%, particularly for leaves in mid-canopy positions (cumulative leaf area index ≤1.5 m2 m-2), those that experience predominantly short-duration sunflecks, and those with high photosynthetic capacities

Economic development and health status among the poor in squatter settlements of Karachi.

OBJECTIVE: Socioeconomic status is an important determinant of health outcome measures. This study examines and presents some of the important health outcomes amongst the higher and lower socioeconomic groups within the urban poor. SETTING: Data analysis is based on a Health and Demographic Survey conducted in urban squatter settlements of Karachi in 1996. METHODS: A structured questionnaire was administered to all households in the catchment area. The indicator used to assess economic status is ownership of assets. RESULTS: Comparison between the two economic levels shows that the lower socio-economic group was more likely to experience child mortality, (CI; 1.02-1.29, p = 0.02) have lower contraceptive usage (CI; 2.11-2.64; p \u3c 0.001) and childhood immunization rates (CI; 2.08-2.40, p \u3c 0.001). No significant association was observed between economic levels and prevalence of diarrhea. The housing, literacy and employment status was consistently better in the higher economic stratum who were more likely to be Pushto-Punjabi speaking as compared to the Sindhi speaking population. CONCLUSION: To have sustainable improvement in the health status of the poor, those who are most vulnerable need to be identified and programs aiming to improve health should also undertake broader development initiatives like raising family income

Smoking among males in a low socioeconomic area of Karachi

Approximately half of the families in Pakistan reported having at least one smoker in 1992. Smokers were less educated, poorer and more likely to come from a rural background than non-smokers. The proportion of family earnings in poor families with marginal incomes, may be substantial. We conducted this survey to determine the prevalence of cigarette smoking in males over 15 years of age in Azam Basti, an urban squatter settlement of Karachi where 31% of the children less than 5 years old were malnourished. A pretested, structured questionnaire was administered to males aged fifteen years and above, from randomly selected homes in Azam Basti. In our sample of 102 persons the respondents were 38 years old on average, and earned about Rs. 4,500 (US $130) per month. Persons with 10 or more years of education were thrice as likely to have never smoked as compared to those with less than ten years of schooling, (OR = 3.6, 95$140) (OR = 2.4, 95% confidence interval 0.8, 7.3). Smoking is common in urban squatter settlements in Pakistan. Parental smoking and its relationship with malnutrition in children under five is not well documented or publicized, even though there is evidence that it has a contribution. We propose that primary health care programs consider smoking prevention and cessation as community based interventions

Power allocation, bit loading and sub-carrier bandwidth sizing for OFDM-based cognitive radio

The function of the Radio Resource Management module of a Cognitive Radio (CR) system is to evaluate the available resources and assign them to meet the Quality of Service (QoS) objectives of the Secondary User (SU), within some constraints on factors which limit the performance of the Primary User (PU). While interference mitigation to the PU spectral band from the SU's transmission has received a lot of attention in recent literature; the novelty of our work is in considering a more realistic and effective approach of dividing the PU into sub-bands, and ensuring that the interference to each of them is below a specified threshold. With this objective, and within a power budget, we execute the tasks of power allocation, bit loading and sizing the sub-carrier bandwidth for an orthogonal frequency division multiplexing (OFDM)-based SU. After extensively analyzing the solution form of the optimization problems posed for the resource allocation, we suggest iterative algorithms to meet the aforementioned objectives. The algorithm for sub-carrier bandwidth sizing is novel, and not previously presented in literature. A multiple SU scenario is also considered, which entails assigning sub-carriers to the users, besides the resource allocation. Simulation results are provided, for both single and multi-user cases, which indicate the effectiveness of the proposed algorithms in a CR environment

Distributed execution of cognitive relaying with time incentive: multiple PU scenario

The prime focus of this study is in developing distributed algorithms for cognitive relaying with time incentive for multiple primary users (CRTI-M). CRTI-M is a symbiotic paradigm in which the incumbent primary users (PUs) of the spectrum, with weak transmission links, seek cooperation from the cognitive secondary user (SU) nodes in their vicinity, and in return reward them with an incentive time for the latter's own communication. When relaying through the SU network, each PU can either use its own spectrum or that of the other PUs. Cross-layer optimization problems are formulated to enable both these possibilities in a multi-hop multi-channel cognitive radio network with the objective of maximizing the cumulative time incentive for the SUs. Corresponding distributed algorithms are developed, which face the challenge of meeting the constraints of the formulated problems with only local information and the lack of a centralized controller. Further, to make the CRTI-M schemes practically realizable, a MAC scheduling protocol is suggested, which gives emphasis to the distributed implementation and provides a unified framework for the PUs and SUs. Simulation results are furnished to demonstrate the effectiveness of the proposed algorithms

The SS-SCR Scheme for dynamic spectrum access

We integrate the two models of Cognitive Radio (CR), namely, the conventional Sense-and-Scavenge (SS) Model and Symbiotic Cooperative Relaying (SCR). The resultant scheme, called SS-SCR, improves the efficiency of spectrum usage and reliability of the transmission links. SS-SCR is enabled by a suitable cross-layer optimization problem in a multihop multichannel CR network. Its performance is compared for different PU activity patterns with those schemes which consider SS and SCR separately and perform disjoint resource allocation. Simulation results depict the effectiveness of the proposed SS-SCR scheme. We also indicate the usefulness of cloud computing for a practical deployment of the scheme

Dense agent-based HPC simulation of cell physics and signaling with real-time user interactions

Introduction: Distributed simulations of complex systems to date have focused on scalability and correctness rather than interactive visualization. Interactive visual simulations have particular advantages for exploring emergent behaviors of complex systems. Interpretation of simulations of complex systems such as cancer cell tumors is a challenge and can be greatly assisted by using “built-in” real-time user interaction and subsequent visualization.Methods: We explore this approach using a multi-scale model which couples a cell physics model with a cell signaling model. This paper presents a novel communication protocol for real-time user interaction and visualization with a large-scale distributed simulation with minimal impact on performance. Specifically, we explore how optimistic synchronization can be used to enable real-time user interaction and visualization in a densely packed parallel agent-based simulation, whilst maintaining scalability and determinism. We also describe the software framework created and the distribution strategy for the models utilized. The key features of the High-Performance Computing (HPC) simulation that were evaluated are scalability, deterministic verification, speed of real-time user interactions, and deadlock avoidance.Results: We use two commodity HPC systems, ARCHER (118,080 CPU cores) and ARCHER2 (750,080 CPU cores), where we simulate up to 256 million agents (one million cells) using up to 21,953 computational cores and record a response time overhead of ≃350 ms from the issued user events.Discussion: The approach is viable and can be used to underpin transformative technologies offering immersive simulations such as Digital Twins. The framework explained in this paper is not limited to the models used and can be adapted to systems biology models that use similar standards (physics models using agent-based interactions, and signaling pathways using SBML) and other interactive distributed simulations