31 research outputs found
Studies on the influence of temperature and humidity on biological traits of silkworm (Bombyx mori L.; Bombycidae)
Impact of variations in temperature and humidity on pupation, hatchability and larval mortality of eleven inbred silkworm lines M-101, M-103, M-104, M-107, Pak-1, Pak-2, Pak-3, Pak-4, PFI-I, PFI-II and S-1 was investigated during autumn and spring, 2007-2008 at Sericulture Research Laboratory, Lahore. The experiment was laid out in factorial design with replications and the data was pooled over season. The larvae of 4th and 5th instar were exposed to three temperature regimes (25, 30 and 35 ± 1°C). Significant variations in hatchability, pupation and mortality were noticed due to the effect of temperature and relative humidity on 4th and 5th instar larvae of inbred silkworm lines. The maximum mean values of hatchability (93.15), pupation (93.12) and the lowest mean larval mortality (2.60) was observed at 25°C and 70-80% RH. Lower RH of (55 and 65%) even at 25°C lowered the hatchability and pupation of the silkworm lines and contributed significantly in higher larval mortality. The lowest mean value of hatchability (68.96) and pupation (76.55) was recorded at 35°C and 55% RH while highest larval mortality (11.92) was noticed at 35°C with 55% RH. The results indicate that the mean performance of inbred silkworm lines under various conditions of temperature and humidity was significantly different from each other at various temperature and humidity exposures during 4th and 5th instar. At 25°C with 75% RH, the performance of silkworm lines remained consistent but variations in temperature or humidity for three hours significantly affected all three parameters (hatchability, pupation and larval mortality). The results illustrate that hatchability percentage of M-101(84.98), Pak-2 (84.52), Pak-3 (84.32) and Pak-4 (84.05) and pupation rate of Pak-4 (86.60), Pak-2 (86.08), PFI-I (85.33) and M-101(84.88) was significantly better as compared to other silkworm lines. The mean values of larval mortality observed in Pak-2 (5.56), Pak-3 (5.76), PFI-I (6.03) and M-107 (6.20) showed significantly lower mortality. The lower relative humidity level (less than 65%) is not conducive for seed cocoon production even at the optimum temperature of 25°C. The study clearly underlines the importance of optimization of environmental conditions during larval rearing in relation to seed cocoon production. The investigations strongly recommend that temperature and relative humidity in the range of 25-26°C and 70-80% respectively are mandatory for excellent results of egg hatchability, pupation and survival rate (low larval mortality). The results also emphasize that Pak-2, Pak-3, Pak-4, PFI-I, M-101 and M-107 showed better potential for seed production and commercial exploitation.Key words: Sericulture Pakistan, silkworm rearing
Childhood emotional trauma and cyberbullying perpetration among emerging adults: a multiple mediation model of the role of problematic social media use and psychopathology
Research suggests that a small minority of social media users experience problems as a result of their online use. The purpose of the present study was to examine the association of cyberbullying perpetration and problematic social media use with childhood emotional trauma, Cluster B (narcissistic, histrionic, antisocial, and borderline) personality traits, dissociative experiences (DEs), depression, and self-esteem in a nonclinical undergraduate sample. A total of 344 university students volunteered to complete a questionnaire that included measures on the aforementioned dimensions. Thirty-eight percent of the participants had emotional neglect and 27% had emotional abuse, while 44% of them demonstrated at least one cyberbullying perpetration behavior. Results indicated that cyberbullying perpetrators had higher scores on problematic social media use, dissociative experiences, Cluster B traits, depression and childhood emotional trauma, and lower on self-esteem. Path analysis demonstrated that, while adjusting for gender and age, childhood emotional trauma was directly and indirectly associated with cyberbullying perpetration via Cluster B traits. Moreover, depression and dissociation were directly associated with problematic social media use. The findings of this study emphasize the important direct role of childhood emotional trauma and pathological personality traits on cyberbullying perpetration
Determinants of recovery from post-COVID-19 dyspnoea: analysis of UK prospective cohorts of hospitalised COVID-19 patients and community-based controls
Background The risk factors for recovery from COVID-19 dyspnoea are poorly understood. We investigated determinants of recovery from dyspnoea in adults with COVID-19 and compared these to determinants of recovery from non-COVID-19 dyspnoea. Methods We used data from two prospective cohort studies: PHOSP-COVID (patients hospitalised between March 2020 and April 2021 with COVID-19) and COVIDENCE UK (community cohort studied over the same time period). PHOSP-COVID data were collected during hospitalisation and at 5-month and 1-year follow-up visits. COVIDENCE UK data were obtained through baseline and monthly online questionnaires. Dyspnoea was measured in both cohorts with the Medical Research Council Dyspnoea Scale. We used multivariable logistic regression to identify determinants associated with a reduction in dyspnoea between 5-month and 1-year follow-up. Findings We included 990 PHOSP-COVID and 3309 COVIDENCE UK participants. We observed higher odds of improvement between 5-month and 1-year follow-up among PHOSP-COVID participants who were younger (odds ratio 1.02 per year, 95% CI 1.01–1.03), male (1.54, 1.16–2.04), neither obese nor severely obese (1.82, 1.06–3.13 and 4.19, 2.14–8.19, respectively), had no pre-existing anxiety or depression (1.56, 1.09–2.22) or cardiovascular disease (1.33, 1.00–1.79), and shorter hospital admission (1.01 per day, 1.00–1.02). Similar associations were found in those recovering from non-COVID-19 dyspnoea, excluding age (and length of hospital admission). Interpretation Factors associated with dyspnoea recovery at 1-year post-discharge among patients hospitalised with COVID-19 were similar to those among community controls without COVID-19. Funding PHOSP-COVID is supported by a grant from the MRC-UK Research and Innovation and the Department of Health and Social Care through the National Institute for Health Research (NIHR) rapid response panel to tackle COVID-19. The views expressed in the publication are those of the author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health and Social Care. COVIDENCE UK is supported by the UK Research and Innovation, the National Institute for Health Research, and Barts Charity. The views expressed are those of the authors and not necessarily those of the funders
Guiding Principles for Chronic Total Occlusion Percutaneous Coronary Intervention.
Outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have improved because of advancements in equipment and techniques. With global collaboration and knowledge sharing, we have identified 7 common principles that are widely accepted as best practices for CTO-PCI. 1. Ischemic symptom improvement is the primary indication for CTO-PCI. 2. Dual coronary angiography and in-depth and structured review of the angiogram (and, if available, coronary computed tomography angiography) are key for planning and safely performing CTO-PCI. 3. Use of a microcatheter is essential for optimal guidewire manipulation and exchanges. 4. Antegrade wiring, antegrade dissection and reentry, and the retrograde approach are all complementary and necessary crossing strategies. Antegrade wiring is the most common initial technique, whereas retrograde and antegrade dissection and reentry are often required for more complex CTOs. 5. If the initially selected crossing strategy fails, efficient change to an alternative crossing technique increases the likelihood of eventual PCI success, shortens procedure time, and lowers radiation and contrast use. 6. Specific CTO-PCI expertise and volume and the availability of specialized equipment will increase the likelihood of crossing success and facilitate prevention and management of complications, such as perforation. 7. Meticulous attention to lesion preparation and stenting technique, often requiring intracoronary imaging, is required to ensure optimum stent expansion and minimize the risk of short- and long-term adverse events. These principles have been widely adopted by experienced CTO-PCI operators and centers currently achieving high success and acceptable complication rates. Outcomes are less optimal at less experienced centers, highlighting the need for broader adoption of the aforementioned 7 guiding principles along with the development of additional simple and safe CTO crossing and revascularization strategies through ongoing research, education, and training
Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study
Background
No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.
Methods
The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.
Findings
2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7–9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46–0·99]), obesity (0·50 [0·34–0·74]) and invasive mechanical ventilation (0·42 [0·23–0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74–1·00]), at 5 months (0·74 [0·64–0·88]) to 1 year (0·75 [0·62–0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.
Interpretation
The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.
Funding
UK Research and Innovation and National Institute for Health Research
A nonlinear transformation based hybrid evolutionary method for MINLP solution
In the recent past, some of the population based stochastic direct search methods, like genetic algorithms and differential evolution (DE), have been increasingly applied for solving complex optimization problems in diverse applications. Most of the times, Cthough global optimal solutions are obtained, these stochastic methods have slow convergence and take long computational times. The handling of discrete variables has been quite ad hoc; for instance in DE, the algorithm works assuming them as continuous variables during all the steps but only for the objective function evaluation, a truncation operation is used for forcing the integrality requirements. In this paper, we address both, the convergence issues and improved ways of handling discrete variables. A nonlinear transformation proposed in the literature for representing the discrete variables as continuous variables has been explored for alternate ways of solving MINLP problems to global optimality through conversion of MINLP problems into equivalent NLPs. For finding global optimal solutions to the resulting nonconvex NLP and to improve the convergence rate of DE closer to the optimum, in this work a hybrid method combining stochastic and deterministic approaches has been proposed, which seems to be promising within the scope of the case studies considered, though guarantee of the global optimality still remains an issue.© Elsevie
A multilevel, control-theoretic framework for integration of planning, scheduling, and rescheduling
In this paper, an integrated multilevel, control-theoretic framework has been proposed for effectively handling integration of planning, scheduling, and rescheduling. A general resource-constrained, multistage, multiproduct plant operating as a hybrid flowshop facility has been considered. The proposed approach is based on the inherent hierarchical decomposition of the overall decision-making process that is a typical characteristic of large enterprises. The overall problem is segregated into three levels with different horizons, wherein planning over multiperiods is at the top level followed by scheduling for a single period at the middle level and a detailed inventory management schedule for the operator at the lower level. In the hierarchical decomposition, the upper levels are equipped with abstractions of the lower levels and proactiveness for reactive scheduling. The integration. of reactive scheduling is motivated by some of the process control principles like cascade control and the concepts of receding horizon. Using the philosophy of decentralized decision-making, it is demonstrated that the lower levels with accurate models have the flexibility and amenability for rescheduling without upsetting the global performance. As an illustrative case study, cyclic scheduling of a simple refinery flow sheet involving continuous lube production in a resource constrained hybrid flowshop is presented to demonstrate the proposed methodology
Cyclic scheduling of continuous multiproduct plants in a hybrid flowshop facility
This paper addresses cyclic scheduling of continuous multiproduct plants operating in a hybrid flowshop, where the operation in the plant envelope is neither strictly sequential nor in a strictly parallel mode. This plant configuration is typically found in many manufacturing industries because of capacity expansion, debottlenecking, and retrofitting, and it poses problems in inventory handling. In addition, resource constraints are considered in the proposed model, where the feed to the hybrid flowshop is a continuous stream with finite intermediate storage (FIS) on the upstream side. It is shown that the resulting scheduling problem is influenced by both the upstream FIS and the downstream demand-related constraints. Rigorous inventory constraints are proposed to handle FIS on the continuous feed and the intermediate inventory. The proposed mixed-integer nonlinear programming model also incorporates a new and practical way of handling product transitions. In the continuous representation of the time domain, an alternate definition of the time slot is proposed to account for the feed loss during transitions. Finally, the proposed model is generalized to account for the case of slots having zero time duration. The novelties of the proposed formulations are demonstrated on a representative scheduling problem of a refinery
Integration of planning and scheduling in multi-site plants : application to paper manufacturing
In this paper, a general multi-level decomposition based framework has been proposed for integration of planning and scheduling in a multi-site, multi-product plant, with applications to paper manufacturing. The problem involves complex issues relating to large-scale production in a hybrid flowshop configuration, decisions relating to minimizing trim losses, while maintaining on-time delivery of orders. Due to these complexities, the overall problem of integrated planning and scheduling is logically partitioned into several levels, depending on the problem size. As followed in other decomposition-based approaches, the Upper level models are equipped with appropriate abstractions of the lower level constraints. Also from a reactive scheduling point of view, some pro-active measures are embedded into the multi-level structure. The proposed multi-level decomposition scheme is demonstrated on a representative planning and scheduling problem