Rooftop gardening to improve food security in Dhaka city: A review of the present practices

In recent years, the trend of growing vegetables on green roofs has gained momentum as a way of promoting agricultural sustainability in Dhaka City. Rooftop gardens become an important part of urban agriculture's recent rejuvenation and offer alternative spaces for urban markets to grow vegetable products. Green roofs create spaces for vegetable crop production, thereby creating opportunities for agricultural incorporation into urban communities. At present, however, vegetable production activities on rooftops are limited due to multiple challenges that need to be addressed before widespread implementation takes place. Rooftop agriculture can improve various ecosystem services, enhance the biodiversity of urban areas and reduce food insecurity. Food production from green roofs will help support and sustain food for urban communities and provide a rare opportunity to grow food efficiently in typically unused spaces. As human populations become more urbanized and urban consumers become more interested in local food for their families, the use of alternative agricultural production systems, such as green roof technologies, will increase in importance. While cultivating food on buildings is a key component of making cities more sustainable and habitable, green roofs are not the total solution for providing cities with food security. They should be viewed more as a supplement to other sources of food production in urban areas

Mass media utilization to promote public behavior change during COVID-19 situation: A population survey of Dhaka city

A huge amount of information associated with the novel coronavirus disease 2019 (COVID-19) outbreak was circulated by mass media in Bangladesh. There has been a rare example so far of how media intervention during the epidemic can affect the public behaviour of Bangladesh. We aimed to assess mass media's influence on changing public behaviour during the second wave of COVID-19. An online cross-sectional survey among 416 Bangladeshi respondents was conducted between August and September 2021. Besides descriptive statistics, datasets were analyzed through a set of statistical methods such as Pearson’s correlation coefficient, and stepwise multiple regression model. The results showed that knowledge level change towards COVID-19 (10 items) had the highest association with behaviour change towards COVID-19 (16 items), indicating a high adoption of public behavior change. There was a positive significant relationship between the behaviour change towards COVID-19 (16 items) with the media's role in making awareness regarding COVID-19 (r= 0.342, p < .001), while there was a negative relationship between the behaviour change towards COVID-19 (16 items) of the respondents with age of participants (r= -.234, p < .001). The results also disclosed that knowledge level, media credibility, and media check-in had the largest contribution to influence the public behavior change. We also found that social media was highly used media as expected during the COVID-19 outbreak. The outcomes of the survey have vital implications for public behavior change and may support infectious disease suppression and control. Our outcomes also stress the significance of the reliability of information shared via mass media outlets and practical strategies to counter misinformation during the COVID-19 outbreak

Plasma accelerator-based ultrabright x-ray beams from ultrabright electron beams

We provide a pathway to compact ultrabright light sources, based on ultrabright, high energy electron beams emerging from a combination of plasma Wakefield acceleration and plasma photocathodes. While plasma acceleration is known to produce accelerating fields three or four orders of magnitude larger than conventional accelerators, the plasma photocathode allows production of electron beams three or four orders of magnitude brighter than conventional, and thus is suitable to unleash the full potential of plasma accelerators. In particular, this is the case for various types of light sources, which profit enormously from an increased electron beam brightness. Building on the recent first experimental demonstration of the plasma photocathode, in this work we discuss the prospects of plasma photocathodes for key photon source approaches such as x-ray free-electron lasers, betatron radiation, ion-channel lasers and inverse Compton scattering

BIM Roles and Responsibilities in Developing Countries: A Dedicated Matrix for Design-Bid-Build Projects

Building information modeling (BIM) through data-rich digital representation has revolutionized the architecture, engineering, and construction (AEC) industry. BIM implementation in the AEC industry has noticeably increased over the last decade. Various BIM roles have been discussed in the literature to ease the process of BIM implementation, but the BIM roles related to project delivery methods have not been standardized. Stimulated by this need, this study develops a BIM roles and responsibilities matrix (BIM-R&R) in the context of the design−bid−build (DBB) projects for developing countries. A comprehensive literature review has been conducted, followed by a questionnaire survey comprising 105 responses. The results were analyzed to formulate a BIM-R&R matrix, on which the expert opinion was obtained from the BIM experts. The proposed BIM-R&R matrix describes all the roles and their corresponding responsibilities required along the project life cycle phases of DBB projects. The incorporation of BIM roles in the DBB procurement process will aid in the efficient management of all information and data that may be lost due to the fragmented nature of DBB. BIM roles with enhanced communication and coordination will also help in reducing time and cost overruns while maintaining a high-quality product. This study helps the associated construction industry in its efforts to implement BIM on their projects by providing a method by which to assess which BIM roles are necessary. Moreover, it will provide project and construction managers with a clear understanding of the BIM roles in DBB projects

Angled laser triggered electron injection in the electron driven plasma wakefield acceleration scheme : a case study in a pursuit to increase tolerance levels, based on FACET II driver parameters.

Co-axial laser triggered injection of electrons in PWFA can produce high quality witness bunches. In this study, angled injection was examined in a pursuit to increase the tolerance levels of synchronization and experimental misalignments while maintaining the high quality of the witness bunches

A Randomised Controlled Trial of Two Infusion Rates to Decrease Reactions to Antivenom

Background: Snake envenoming is a major clinical problem in Sri Lanka, with an estimated 40,000 bites annually. Antivenom is only available from India and there is a high rate of systemic hypersensitivity reactions. This study aimed to investigate whether the rate of infusion of antivenom reduced the frequency of severe systemic hypersensitivity reactions. Methods and findings: This was a randomized comparison trial of two infusion rates of antivenom for treatment of non-pregnant adult patients (>14 y) with snake envenoming in Sri Lanka. Snake identification was by patient or hospital examination of dead snakes when available and confirmed by enzyme-immunoassay for Russell’s viper envenoming. Patients were blindly allocated in a 11 randomisation schedule to receive antivenom either as a 20 minute infusion (rapid) or a two hour infusion (slow). The primary outcome was the proportion with severe systemic hypersensitivity reactions (grade 3 by Brown grading system) within 4 hours of commencement of antivenom. Secondary outcomes included the proportion with mild/moderate hypersensitivity reactions and repeat antivenom doses. Of 1004 patients with suspected snakebites, 247 patients received antivenom. 49 patients were excluded or not recruited leaving 104 patients allocated to the rapid antivenom infusion and 94 to the slow antivenom infusion. The median actual duration of antivenom infusion in the rapid group was 20 min (Interquartile range[IQR]:20–25 min) versus 120 min (IQR:75–120 min) in the slow group. There was no difference in severe systemic hypersensitivity reactions between those given rapid and slow infusions (32% vs. 35%; difference 3%; 95%CI:−10% to +17%;p = 0.65). The frequency of mild/moderate reactions was also similar. Similar numbers of patients in each arm received further doses of antivenom (30/104 vs. 23/94). Conclusions: A slower infusion rate would not reduce the rate of severe systemic hypersensitivity reactions from current high rates. More effort should be put into developing better quality antivenoms

Plasma-photonic spatiotemporal synchronization of relativistic electron and laser beams

Modern particle accelerators and their applications increasingly rely on precisely coordinated interactions of intense charged particle and laser beams. Femtosecond-scale synchronization alongside micrometre-scale spatial precision are essential e.g. for pump-probe experiments, seeding and diagnostics of advanced light sources and for plasma-based accelerators. State-of-the-art temporal or spatial diagnostics typically operate with low-intensity beams to avoid material damage at high intensity. As such, we present a plasma-based approach, which allows measurement of both temporal and spatial overlap of high-intensity beams directly at their interaction point. It exploits amplification of plasma afterglow arising from the passage of an electron beam through a laser-generated plasma filament. The corresponding photon yield carries the spatiotemporal signature of the femtosecond-scale dynamics, yet can be observed as a visible light signal on microsecond-millimetre scales

Measurements of branching fraction ratios and CP-asymmetries in suppressed B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^- decays

We report the first reconstruction in hadron collisions of the suppressed decays B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^-, sensitive to the CKM phase gamma, using data from 7 fb^-1 of integrated luminosity collected by the CDF II detector at the Tevatron collider. We reconstruct a signal for the B^- -> D(-> K^+ pi^-)K^- suppressed mode with a significance of 3.2 standard deviations, and measure the ratios of the suppressed to favored branching fractions R(K) = [22.0 \pm 8.6(stat)\pm 2.6(syst)]\times 10^-3, R^+(K) = [42.6\pm 13.7(stat)\pm 2.8(syst)]\times 10^-3, R^-(K)= [3.8\pm 10.3(stat)\pm 2.7(syst]\times 10^-3, as well as the direct CP-violating asymmetry A(K) = -0.82\pm 0.44(stat)\pm 0.09(syst) of this mode. Corresponding quantities for B^- -> D(-> K^+ pi^-)pi^- decay are also reported.Comment: 8 pages, 1 figure, accepted by Phys.Rev.D Rapid Communications for Publicatio

Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO