170 research outputs found
Shearfree Condition and dynamical Instability in gravity
The implications of shearfree condition on instability range of anisotropic
fluid in are studied in this manuscript. A viable model is
chosen to arrive at stability criterion, where is Ricci scalar and is
the trace of energy momentum tensor. The evolution of spherical star is
explored by employing perturbation scheme on modified field equations and
contracted Bianchi identities in . The effect of imposed shearfree
condition on collapse equation and adiabatic index is studied in
Newtonian and post-Newtonian regimes.Comment: 16 page
Swapping in lattice-based cell migration models
Cell migration is frequently modelled using on-lattice agent-based models (ABMs) that employ the excluded volume interaction. However, cells are also capable of exhibiting more complex cell-cell interactions, such as adhesion, repulsion, pulling, pushing and swapping. Although the first four of these have already been incorporated into mathematical models for cell migration, swapping has not been well studied in this context. In this paper, we develop an ABM for cell movement in which an active agent can `swap' its position with another agent in its neighbourhood with a given swapping probability. We consider a two-species system for which we derive the corresponding macroscopic model and compare it with the average behaviour of the ABM. We see good agreement between the ABM and the macroscopic density. We also analyse the movement of agents at an individual level in the single-species as well as two-species scenarios to quantify the effects of swapping on an agent's motility.<br/
Swapping in lattice-based cell migration models
Cell migration is frequently modelled using on-lattice agent-based models
(ABMs) that employ the excluded volume interaction. However, cells are also
capable of exhibiting more complex cell-cell interactions, such as adhesion,
repulsion, pulling, pushing and swapping. Although the first four of these have
already been incorporated into mathematical models for cell migration, swapping
is an interaction that has not been well studied in this context. In this
paper, we develop an ABM to describe cell movement where an active agent can
`swap' its position with another agent in its neighbourhood with a given
swapping probability. We consider single-species and two-species systems. In
both cases, we derive the corresponding macroscopic model and compare it with
the average behaviour of the ABM. We see good agreement between the ABM and the
macroscopic density. We also derive an expression for the cell-level diffusion
coefficient in terms of the swapping probability and cell density. We conclude
by showing applications of swapping by using the ABM to represent cell movement
with proliferation and cell-cell adhesion.Comment: 32 pages, 12 figures, articl
3-D Printed space maintainers - A review
Although the idea of a digital workflow is not new in dentistry, it has just recently started to be applied in pediatric dentistry. Fabrication of space maintainer is a time-consuming procedure that needs constant communication with the laboratory to be receive and provide patients the best outcomes. These devices maintain space created by premature tooth loss so that the erupting permanent teeth will not experience any kind of malocclusion As a result of clinician's natural curiosity 3-D printed space maintainer have been developed. The advanced CAD/CAM technology used for fabricating digital space maintainers improves patient experience and compliance. The current paper provides an insight on available conventional space maintainers and various aspects of technologically advanced digitainers
Histopathological changes and antioxidant responses in common carp (Cyprinus carpio) exposed to copper nanoparticles
This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this recordDespite the rapid increase of nanotechnology in a wide array of industrial sectors, the biosafety profile of nanomaterials remains undefined. The accelerated use of nanomaterials has increased the potential discharge of nanomaterials into the environment in different ways. The aquatic environment is mainly susceptible as it is likely to act as an ultimate sink for all contaminants. Therefore, this study assessed the toxicological impacts of waterborne engineered copper nanoparticles (Cu-NPs) on histology, lipid peroxidation (LPO), catalase (CAT), and glutathione (GSH) levels in the gills of common carp (Cyprinus carpio). Nanoparticles were characterized by XRD and SEM techniques. Before starting the sub-acute toxicity testing, 96 h LC50 of Cu-NPs for C. carpio was calculated as 4.44 mg/l. Then based on LC50, C. carpio of 40–45 g in weight were exposed to three sub-lethal doses of waterborne engineered Cu-NPs (0 or 0.5 or 1 or 1.5 mg/l) for a period of 14 days. The waterborne Cu-NPs have appeared to induce alterations in gill histology and oxidative stress parameters in a dose-dependent manner. The gill tissues showed degenerative secondary lamellae, necrotic lamella, fused lamella, necrosis of the primary and secondary lamella, edema, complete degeneration, epithelial lifting, degenerative epithelium, and hyperplasia in a dose-dependent manner. In the gill tissues, waterborne Cu-NPs caused a decreased level of CAT and elevated levels of LPO, and GSH in the fish exposed to the highest dose of 1.5 mg Cu-NPs/l of water. Our results indicate that the exposure to waterborne Cu-NPs was toxic to the aquatic organisms as shown by the oxidative stresses and histological alterations in C. carpio, a freshwater fish of good economic value
Novel variants underlying autosomal recessive intellectual disability in Pakistani consanguineous families
Background: Intellectual disability (ID) is both a clinically diverse and genetically heterogeneous group of disorder,
with an onset of cognitive impairment before the age of 18 years. ID is characterized by significant limitations in
intellectual functioning and adaptive behaviour. The identification of genetic variants causing ID and neurodevelopmental
disorders using whole-exome sequencing (WES) has proven to be successful. So far more than 1222 primary and 1127
candidate genes are associated with ID.
Methods: To determine pathogenic variants causative of ID in three unrelated consanguineous Pakistani families, we used a
combination of WES, homozygosity-by-descent mapping, de-deoxy sequencing and bioinformatics analysis.
Results: Rare pathogenic single nucleotide variants identified by WES which passed our filtering strategy were confirmed by
traditional Sanger sequencing and segregation analysis. Novel and deleterious variants in VPS53, GLB1, and MLC1, genes
previously associated with variable neurodevelopmental anomalies, were found to segregate with the disease in the three
families.
Conclusions: This study expands our knowledge on the molecular basis of ID as well as the clinical heterogeneity associated
to different rare genetic causes of neurodevelopmental disorders. This genetic study could also provide
additional knowledge to help genetic assessment as well as clinical and social management of ID in Pakistani
familie
Development of an on-job mentorship programme to improve nursing experience for enhanced patient experience of compassionate care
Background: Evidence suggests improvement in nursing staff satisfaction, competence, and retention after implementation of evidence-based mentorship programmes. When guided by a framework of compassion, mentoring as a caring action can not only build healthy, transformative relationships but a similar behavior is reciprocated to patients which subsequently can drive patient experience of care. However, examples of on-job mentorship programs for nurses in low- and middle-income countries (LMIC) are limited.Objective: The objective of the study was to develop an on-job nursing mentorship programme using a compassionate framework aimed at improving nurses\u27 experience and thus enhancing patient experience in a tertiary care hospital in Pakistan.Methods: Designed as an intervention development study, it was completed between January 2018-December 2019. The programme was developed by a team composed of service and nursing leadership, director patient experience of care and a compassion specialist using a theory of change model. The package followed a series of steps, a) identification of a framework, b) creation of working group c) needs assessment and d) multiple meetings to frame the model followed by implementing the preconditions for roll-out of the programme with the frontline staff.Results: The eventual outcome was improving the patient\u27s experience of compassion while the intermediate outcome was to have nurses demonstrate compassionate care. The pre-conditions were identified as: recruitment of staff with appropriate skills for pediatric care, provision of compassionate experience to the frontline nurses by addressing their specific pain points, development of competent head nurses as supervisors and creation of a compassionate culture. To ensure the pre-conditions, various interventions were planned with some implemented through the course of the study while others are in the process of being rolled out. These involved, inclusion of pediatric compassion specific module during orientation of new hires, creation of space to talk about compassionate skills with staff, provision of trainings and mentorship to create competent head nurses, and creating a culture that promoted and recognized compassionate care values.Conclusion: The approach helped to delineate feasible pathways for an on-job compassionate mentorship programme enhancing routine supervisors\u27 role as facilitators of compassionate care
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Synthesis and toxicity assessment of environment friendly high yield ceria nanoparticles for biosafety
Different compounds at nanoscale level show more efficient behavior because of increased surface area and optical properties. CeO2 nanoparticles are of great importance for their unique properties. However, the extensive release of CeO2 nanoparticles in the environment is also a serious problem that must be addressed as available data related to ceria toxicity is currently not comprehensive. The present study was aimed to evaluate the potential of CeO2 nanoparticles in biomedical applications and assessment of their toxicity by using mutagenic and acute in-vivo approaches. High yield CeO2 nanoparticles with spherical morphology and with an average size of 40 nm were synthesized by adopting the alkaline fusion method under mild conditions. The synthesized CeO2 nanoparticles showed antibacterial activity at different concentrations (50–500 µg/mL) against E. coli. The antioxidant properties of CeO2 nanoparticles were determined, and CeO2 nanoparticles show antioxidant behavior that may be helpful for anti-cancer and anti-inflammatory drug preparation. Ames test confirms no mutagenicity at different concentrations of CeO2 nanoparticles. Moreover, in the current study CeO2 nanoparticles showed no toxicity for aquatic life even at a concentration of 100 mg/L in the same way the in-vivo toxicology was not evident even at the highest concentration (≥5000 mg/kg BW for rats), no significant change was observed in hematological and biochemical parameters of control and CeO2nanoparticles exposed rats. In-vivo dermal toxicity was not observed in rabbits at the application of 0.5 g CeO2 nanoparticles. These results indicate the nontoxic nature of these nanomaterials. However, further experimentation is recommended to completely define the toxic potential of the nanomaterials
Rapid mechanosensitive migration and dispersal of newly divided mesenchymal cells aid their recruitment into dermal condensates
Embryonic mesenchymal cells are dispersed within an extracellular matrix but can coalesce to form condensates with key developmental roles. Cells within condensates undergo fate and morphological changes and induce cell fate changes in nearby epithelia to produce structures including hair follicles, feathers, or intestinal villi. Here, by imaging mouse and chicken embryonic skin, we find that mesenchymal cells undergo much of their dispersal in early interphase, in a stereotyped process of displacement driven by 3 hours of rapid and persistent migration followed by a long period of low motility. The cell division plane and the elevated migration speed and persistence of newly born mesenchymal cells are mechanosensitive, aligning with tissue tension, and are reliant on active WNT secretion. This behaviour disperses mesenchymal cells and allows daughters of recent divisions to travel long distances to enter dermal condensates, demonstrating an unanticipated effect of cell cycle subphase on core mesenchymal behaviour
Changing social contact patterns among US workers during the COVID-19 pandemic: April 2020 to December 2021
Non-pharmaceutical interventions minimize social contacts, hence the spread of respiratory pathogens such as influenza and SARS-CoV-2. Globally, there is a paucity of social contact data from the workforce. In this study, we quantified two-day contact patterns among USA employees. Contacts were defined as face-to-face conversations, involving physical touch or proximity to another individual and were collected using electronic self-kept diaries. Data were collected over 4 rounds from 2020 to 2021 during the COVID-19 pandemic. Mean (standard deviation) contacts reported by 1456 participants were 2.5 (2.5), 8.2 (7.1), 9.2 (7.1) and 10.1 (9.5) across round 1 (April-June 2020), 2 (November 2020-January 2021), 3 (June-August 2021), and 4 (November-December 2021), respectively. Between round 1 and 2, we report a 3-fold increase in the mean number of contacts reported per participant with no major increases from round 2-4. We then modeled SARS-CoV-2 transmission at home, work, and community settings. The model revealed reduced relative transmission in all settings in round 1. Subsequently, transmission increased at home and in the community but remained exceptionally low in work settings. To accurately parameterize models of infection transmission and control, we need empirical social contact data that capture human mixing behavior across time
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