77 research outputs found
Some Fixed Point Theorems in -Metric Space Endowed with Graph
We define some notions of contraction mappings in -metric space endowed with a graph and subsequently establish some fixed point results for such classes of contractions. According to the applications of our results, we obtain fixed point theorems for cyclic operators and an existence theorem for the solution of an integral equation
HEMATOLOGICAL VARIATIONS AND ASSESMENT OF HEAVY METALS IN SINDH SPARROW (PASSER PYRRHONOTUS) AS A BIOINDICATOR IN PUNJAB AREAS OF PAKISTAN
Sindh sparrows, prevalent in Sindh region of Pakistan, are non-migratory birds abundant in human-inhabited areas globally, except Antarctica. Given their close association with human settlements, these birds serve as crucial indicators for biological monitoring in regions affected by pollution. This study focused on assessing the hematological parameters and heavy metal concentrations in various organs of Sindh sparrows in the Punjab regions of Pakistan. The collected blood samples underwent analysis for hematological indices and heavy metal concentrations. The results indicated variability in hematological analysis of sparrows. Fluctuations were observed in the concentrations of different heavy metals, with significant differences in zinc and iron, while chromium, cadmium, and nickel concentrations showed non-significant differences. The patterns of heavy metal accumulation revealed higher concentrations of chromium, nickel, and iron in the liver, contrasting with the cadmium and zinc in kidneys. In conclusion, significant correlations were observed among the concentrations of Zinc, Chromium, Cadmium, Nickel, and Iron in kidney, liver, and muscles of both male and female Sindh sparrows. The findings underscore the need for further comprehensive studies to assess heavy metal accumulation in birds, highlighting the urgency to address environmental pollution that poses risks to avian species and human populations worldwide
SE in ES:Opportunities for Software Engineering and Cloud Computing in Environmental Science
New and emergent computing architectures and software engineering practices provide an opportunity for environmental models to be deployed more efficiently and democratically. In this paper we aim to capture the software engineering practices of environmental scientists, highlight opportunities for software engineering and work towards developing a domain specific language for the configuration and deployment of environmental models. We hold a series of interviews with environmental scientists involved in developing and deploying computer based environmental models about the approach taken in engineering models, and describe a case study in deploying an environmental model (WRF: Weather Research & Forecasting) on a cloud architecture. From these studies we find a number of opportunities for a) software engineering methods and tools such as Domain Specific Languages to play a role in abstracting from underlying computing complexity, and for b) new architectures to increase efficiency and availability of deployment. Together, we propose they will allow scientists to concentrate on fundamental science rather than specifics of the underlying computing
SARS-CoV-2 RNA detected in blood products from patients with COVID-19 is not associated with infectious virus
Background: Laboratory diagnosis of SARS-CoV-2 infection (the cause of COVID-19) uses PCR to detect viral RNA (vRNA) in respiratory samples. SARS-CoV-2 RNA has also been detected in other sample types, but there is limited understanding of the clinical or laboratory significance of its detection in blood. Methods: We undertook a systematic literature review to assimilate the evidence for the frequency of vRNA in blood, and to identify associated clinical characteristics. We performed RT-PCR in serum samples from a UK clinical cohort of acute and convalescent COVID-19 cases (n=212), together with convalescent plasma samples collected by NHS Blood and Transplant (NHSBT) (n=462 additional samples). To determine whether PCR-positive blood samples could pose an infection risk, we attempted virus isolation from a subset of RNA-positive samples. Results: We identified 28 relevant studies, reporting SARS-CoV-2 RNA in 0-76% of blood samples; pooled estimate 10% (95%CI 5-18%). Among serum samples from our clinical cohort, 27/212 (12.7%) had SARS-CoV-2 RNA detected by RT-PCR. RNA detection occurred in samples up to day 20 post symptom onset, and was associated with more severe disease (multivariable odds ratio 7.5). Across all samples collected â„28 days post symptom onset, 0/494 (0%, 95%CI 0-0.7%) had vRNA detected. Among our PCR-positive samples, cycle threshold (ct) values were high (range 33.5-44.8), suggesting low vRNA copy numbers. PCR-positive sera inoculated into cell culture did not produce any cytopathic effect or yield an increase in detectable SARS-CoV-2 RNA. Conclusions: vRNA was detectable at low viral loads in a minority of serum samples collected in acute infection, but was not associated with infectious SARS-CoV-2 (within the limitations of the assays used). This work helps to inform biosafety precautions for handling blood products from patients with current or previous COVID-19
Convalescent plasma therapy for the treatment of patients with COVIDâ19: Assessment of methods available for antibody detection and their correlation with neutralising antibody levels
Introduction
The lack of approved specific therapeutic agents to treat coronavirus disease (COVIDâ19) associated with severe acute respiratory syndrome coronavirus 2 (SARSâCoVâ2) infection has led to the rapid implementation of convalescent plasma therapy (CPT) trials in many countries, including the United Kingdom. Effective CPT is likely to require high titres of neutralising antibody (nAb) in convalescent donations. Understanding the relationship between functional neutralising antibodies and antibody levels to specific SARSâCoVâ2 proteins in scalable assays will be crucial for the success of a largeâscale collection. We assessed whether neutralising antibody titres correlated with reactivity in a range of enzymeâlinked immunosorbent assays (ELISA) targeting the spike (S) protein, the main target for human immune response.
Methods
Blood samples were collected from 52 individuals with a previous laboratoryâconfirmed SARSâCoVâ2 infection. These were assayed for SARSâCoVâ2 nAbs by microneutralisation and pseudoâtype assays and for antibodies by four different ELISAs. Receiver operating characteristic (ROC) analysis was used to further identify sensitivity and specificity of selected assays to identify samples containing high nAb levels.
Results
All samples contained SARSâCoVâ2 antibodies, whereas neutralising antibody titres of greater than 1:20 were detected in 43 samples (83% of those tested) and >1:100 in 22 samples (42%). The best correlations were observed with EUROimmun immunoglobulin G (IgG) reactivity (Spearman Rho correlation coefficient 0.88; p 1:100 with 100% specificity using a reactivity index of 9.1 (13/22).
Discussion
Robust associations between nAb titres and reactivity in several ELISAâbased antibody tests demonstrate their possible utility for scaledâup production of convalescent plasma containing potentially therapeutic levels of antiâSARSâCoVâ2 nAbs
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The Role of Digital Technologies in Responding to the Grand Challenges of the Natural Environment:The Windermere Accord
Digital technology is having a major impact on many areas of society, and there is equal opportunity for impact on science. This is particularly true in the environmental sciences as we seek to understand the complexities of the natural environment under climate change. This perspective presents the outcomes of a summit in this area, a unique cross-disciplinary gathering bringing together environmental scientists, data scientists, computer scientists, social scientists, and representatives of the creative arts. The key output of this workshop is an agreed vision in the form of a framework and associated roadmap, captured in the Windermere Accord. This accord envisions a new kind of environmental science underpinned by unprecedented amounts of data, with technological advances leading to breakthroughs in taming uncertainty and complexity, and also supporting openness, transparency, and reproducibility in science. The perspective also includes a call to build an international community working in this important area
Quantifying neutralising antibody responses against SARS-CoV-2 in dried blood spots (DBS) and paired sera
The ongoing SARS-CoV-2 pandemic was initially managed by non-pharmaceutical interventions such as diagnostic testing, isolation of positive cases, physical distancing and lockdowns. The advent of vaccines has provided crucial protection against SARS-CoV-2. Neutralising antibody (nAb) responses are a key correlate of protection, and therefore measuring nAb responses is essential for monitoring vaccine efficacy. Fingerstick dried blood spots (DBS) are ideal for use in large-scale sero-surveillance because they are inexpensive, offer the option of self-collection and can be transported and stored at ambient temperatures. Such advantages also make DBS appealing to use in resource-limited settings and in potential future pandemics. In this study, nAb responses in sera, venous blood and fingerstick blood stored on filter paper were measured. Samples were collected from SARS-CoV-2 acutely infected individuals, SARS-CoV-2 convalescent individuals and SARS-CoV-2 vaccinated individuals. Good agreement was observed between the nAb responses measured in eluted DBS and paired sera. Stability of nAb responses was also observed in sera stored on filter paper at room temperature for 28Â days. Overall, this study provides support for the use of filter paper as a viable sample collection method to study nAb responses.</p
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