Time Lapse Research Articles

Decreased DNA density is a better indicator of a nuclear bleb than lamin B loss.

Nuclear blebs are herniations of the nucleus that occur in diseased nuclei that cause nuclear rupture leading to cellular dysfunction. Chromatin and lamins are two of the major structural components of the nucleus that maintain its shape and function, but their relative roles in nuclear blebbing remain elusive. To determine the composition of nuclear blebs, we compared the immunofluorescence intensity of DNA and lamin B in the main nucleus body to the nuclear bleb across cell types and perturbations. DNA density in the nuclear bleb was consistently decreased to about half of the nuclear body while lamin B levels in the nuclear bleb varied widely. Partial Wave Spectroscopic (PWS) microscopy recapitulated significantly decreased likelihood of high-density domains in the nuclear bleb versus body, independent of lamin B. Time lapse imaging into immunofluorescence reveals that decreased DNA density marks all nuclear blebs while decreased lamin B1 levels only occur in blebs that have recently ruptured. Thus, decreased DNA density is a better marker of a nuclear bleb than lamin B level.

041. A Case of Cholangiocarcinoma in A Young Adolescent

Background: Cholangiocarcinoma usually occurs in 50-70 years age group. Recent study showed an increased incidence in younger age group. We describe a case of Cholangiocarcinoma in an adolescent girl in order to understand its natural history. Case: A 16 year old girl presented with 2 months history of jaundice, itchyness, right upper quadrant abdominal pain, pale stool and dark urine. Initial investigation showed : Total Bilirubin 8.87, (Direct 3.53, Indirect 12.40), SGOT 75, SGPT 56, ALP 240, GGT 59, Hepatitis B and C negative, AFP 1.96, CA19-9 3.1, and CEA 5.1. Imaging showed dilated hepatic duct with 1.5cm mass in mid-Common Bile Duct (CBD). Due to unforeseen personal circumstances, surgery was done 16 months from onset of complaints. Tumor was found at junction of cystic duct + CBD. The CBD and Gallbladder was resected (with frozen section), lymph node dissected along hepatic artery, Roux-en-Y hepaticojejunostomy anastomosis and Jejuno-Jejunostomy anastomosis was performed. Histopathology showed Cholangiocarcinoma grade 2 with perineural + lymphovascular invasion, and malignant cells’ perineural invasion at proximal margin. She underwent adjuvant chemotherapy (Gemcitabine + Cisplatin). CT scan 6 months post Chemotherapy showed 3cm lesion in CBD. After a further 2 months of chemotherapy, CT evaluation showed no residual mass left. Conclusion: This highlight that despite significant time lapse from onset of symptoms, surgery with curative intent may still be considered. Secondly, chemotherapy is an extremely important part of the treatment, especially in presence of malignant cells at resection margin.

Has risk management plan system influenced the speed of package insert revisions in Japan?

The system of Risk Management Plan in Japan (J-RMP) is a relatively new system, implemented in 2013; thus, its effect on safety measures is still unclear. One of the purposes of J-RMP is to enhance the postmarketing safety measures to be ensured by publishing J-RMP and sharing information on risk management among healthcare professionals. We hypothesized that this might enable information about postmarketing adverse events to be accumulated rapidly, potentially accelerating the identification of adverse reactions (ARs). Herein, we focused on the speed of adding clinically significant ARs (CSARs) to package inserts (PIs) as an indicator of the rapidity of AR identification, investigated the impact of the J-RMP system on PI revisions. We investigated the "Notice of Revision of Precautions" on the website of Pharmaceuticals and Medical Devices Agency (PMDA), targeting PI revisions with the addition of CSARs from April 2003 to March 2023, which corresponds to 10 years before and after J-RMP implementation in April 2013. We created an original database from public information of PMDA and investigated the speed of adding CSARs to PIs. Comparing the time lapse from drug approvals to PI revisions after J-RMP implementation (149 cases) to that before implementation (318 cases), the median value was 32 months for both. Regarding the time lapse when the additional CSARs were listed and unlisted as safety concerns at the time of approvals, it was 35 months vs. 32 months (14 cases vs. 126 cases, p = 0.7820), with no statistically significant difference. Conversely, there were significant differences within each AR and each drug therapeutic category. This study revealed that the rapidity of risk identification as ARs was not affected by J-RMP, and it may be affected by the characteristics of each AR and each drug therapeutic category. It is expected that other J-RMP benefits, such as risk prevention before the occurrence, will be utilized to further develop strategies for the effective utilization of the J-RMP for safety measures in Japan.

Long‐Term Monitoring of ApoE4 within Aqueous Humor Using Intraocular Lenses Containing Target‐Responsive Inverse Opal Hydrogel

Neurodegenerative diseases, including Alzheimer's disease (AD), pose significant challenges to global healthcare because of their irreversible postsymptomatic progression. Conventional radiographic techniques have limitations in early detection, owing to the time lapse between symptom recognition by individuals and precise inspection using medical instruments. Current research explores ophthalmic approaches to address this gap, investigating the physiological link between ocular health and brain diseases. Intraocular lenses (IOLs), widely used in cataract and refractive surgeries, provide a safe and minimally invasive platform for the continuous monitoring of neurodegenerative disease biomarkers, including those associated with AD. By integrating biomolecule‐responsive sensors with IOLs, it becomes feasible to achieve early diagnosis and long‐term, noninvasive monitoring postimplantation. Herein, a fluorescently labeled inverse opal hydrogel (FIOH) is merged with IOLs for ApoE4 detection, a key risk factor for AD. The permeability and inherent photonic properties of FIOH facilitate the cumulative enhancement of the fluorescence signal. In a simulation of the aqueous humor circulation, the detection limit for ApoE4 is determined to be 0.1 nM. Therefore, FIOH‐integrated IOLs hold promise not only for early detection but also for providing a reliable platform for the continuous, noninvasive monitoring of neurodegenerative diseases after the initial, minimally invasive implantation.

Timosaponin AIII Disrupts Cell-Extracellular Matrix Interactions through the Inhibition of Endocytic Pathways.

Timosaponin AIII (TAIII), a steroidal saponin isolated from the root of Anemarrhena asphodeloides Bunge, exhibits various pharmacological activities, including anti-cancer properties. TAIII inhibits the migration and invasion of various cancer cell types. However, the mechanism underlying how TAIII regulates the motility of cancer cells remains incompletely understood. In this study, we demonstrate that TAIII disrupted cell-extracellular matrix (ECM) interactions by inhibiting internalization of cell surface proteins, such as integrins. We found that TAIII inhibited cell adhesion on various ECMs. Structure-activity relationship analysis demonstrated that TAIII exhibited unique activity among the saponins from Anemarrhena asphodeloides Bunge and that the number and position of saccharide moieties were important for TAIII to exert its activity. Time lapse imaging revealed that TAIII also suppressed cell spreading on the ECM, membrane ruffling, and lamellipodia formation. Furthermore, we examined integrin β1 behaviors in response to TAIII treatment and found that TAIII blocked its internalization. These findings contribute to delineating the potential molecular mechanisms by which TAIII exerts anti-metastatic activity.

Geology and geochronology of the El Peñón granitic pluton: A contribution to the famatinian magmatic evolution in the Sierra de San Luis, Argentina

The El Peñón pluton is a peraluminous granite located in the northeastern sector of the Sierra de San Luis. According to its textural and mineral variations two endmember facies have been distinguished along it: a coarse-grained muscovite-bearing facies, and a fine-grained biotite-bearing facies. Field relationships aligned with mineralogical and geochemical compositions, allow us to establish an anatectic origin for this pluton. Regarding the inherited zircon ages, the provenance area of the metasedimentary source could be linked to the orogenic systems of Western Gondwana. The analysis of the internal structure of the intrusive body related with the structural arrangement observed in the country rocks indicates a syn-kinematic emplacement of the igneous body with respect to the main deformational event described in the Sierra de San Luis, which has been assigned to the closure of the Famatinian arc. New U-Pb (LA-ICP-MS) zircon ages constrain the emplacement/crystallization age of the El Peñón granite within the time lapse between ∼470 and 460 Ma. The geochronological data presented here, together with geochemical and structural analysis, enables us to correlate the origin of the El Peñón pluton and the deformation that occurred during its emplacement with the Famatinian Orogeny. Thus, these results allow us to rule out the presence of Pampean magmatism in the Sierra de San Luis but also establish a new absolute age for the main deformational event of the range.

8704 A DREADD-base Chemogenetic Approach to Quiz the Impact of the Delta Cell Input on Islet Hormone Secretion

Abstract Disclosure: D. Hakim Rodriguez: None. A. Tamayo: None. R. Rodriguez Diaz: None. E. Pereira: None. O. Alcazar: None. M. Makhmutova: None. The utilization of DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) that are gated by clozapine-N-oxide (CNO) enables the selective stimulation of genetically specified cell types in vivo. This chemogenetic technology has been successfully applied in various in vivo studies, including those using mice, to remotely control GPCR signaling in specific cells, such as neurons, glia cells, pancreatic β-cells, or cancer cells. Utilizing DREADDs in the study of pancreatic islets, particularly in the somatostatin-producing δ-cells, could offer insights into the complex role of this hormone. Somatostatin is known to inhibit the secretion of other islet hormones, such as insulin and glucagon, but the detailed mechanisms of its action have not been fully elucidated. To address this, we generated mice enabling the expression of either the activator-DREADD Gq or the inhibitor-DREADD Gi in the mouse somatostatin secreting cells, including the islet δ-cell. Immunohistochemical staining of pancreas sections showed that DREADD were expressed and translocated to the membrane of the islet δ-cells. Perifusion experiments with isolated islets showed that δ-cells responded to CNO stimulation as expected. Islets bearing the DREADD Gq secreted somatostatin in a dose-dependent manner, while somatostatin secretion was inhibited in those expressing DREADD Gi. Secretion of insulin and glucagon were modulated upon activation or inhibition of δ-cells via CNO/DREADD manipulation. CNO-driven pulses of somatostatin stimulation caused asynchronous off responses of neighboring α-and β-cells during the time lapses of somatostatin secretion falloff, resulting in a net increment in the magnitude of both insulin and glucagon secretion. Meanwhile, inhibition of somatostatin secretion surprisingly unleashed glucagon secretion in non-permissive 16mM glucose. These results encouraged us to explore the potential application of DREADD tools in isolated human islets. We will discuss our current approaches whilst using viral vectors to drive the expression of DREADDs in human δ-cells and its impact in the overall islet secretory output. Presentation: 6/2/2024

Comparative analysis of short versus long co-incubation of gametes on post-insemination outcomes and embryo morphokinetics: a sibling oocyte randomized study

Research questionDoes a short co-incubation of gametes in conventional IVF impact post-insemination outcomes and embryo morphokinetics? DesignSibling oocyte randomized pilot study performed between December 2020 and March 2023. Eligible couples (n=55) were female aged 18-43 years with body mass index (BMI) ≤35 and male normal semen parameters. Cumulus oocyte complexes (COCs) (min 6 - max 12) were randomized in a 1:1:2 proportion in long (16-18 hrs), or short (2 hrs) co-incubation IVF exposure, and ICSI, respectively. All oocytes inseminated via IVF were monitored by time-lapse (TL). Blastocysts of ≥BL3CC were subjected to trophectoderm (TE) biopsy on day (D)5, D6 or D7 by next generation sequencing (NGS). ResultsA total of 954 COCs were distributed to long co-incubation (n=235, 24.6%), short co-incubation (n=235, 24.6%), and ICSI (n=484, 50.3%). In total, 202 were MII after long co-incubation, 209 after short co-incubation and 394 at ICSI. Regression analyses showed both short co-incubation groups (OR: 0.72, 95% CI: 0.46–1.11, P=0.139) and ICSI (OR: 1.43, 05% CI: 0.95–2.15, P=0.090) did not significantly impact normal fertilization rates (2PN) when compared to long co-incubation. Usable blastocysts per MII, per 2PN, and euploid blastocysts per MII, per 2PN and per tested blastocysts were similar among the groups. The rate of embryo arrest (HR: HR: 0.79, 95% CI: 0.57-1.11, P=0.183) and timings to reach morphokinetic milestones among embryos reaching blastulation were similar between IVF groups (P>0.05, for all). ConclusionA short 2-hour co-incubation of gametes in IVF yields comparable fertilization, blastocyst, and euploidy rates without adverse embryo morphokinetic events, compared to standard overnight co-incubation.

Examining Impact of Insurance Type on Genetic Testing in Pediatric Neurology

ObjectiveStudies that examine the impact of insurance type on the ease of obtaining genetic testing are scarce. Therefore, we aim to analyze how different types of insurance influence the time taken to obtain genetic test results among pediatric neurology patients. MethodsThis was a retrospective cohort study from Dayton Children’s Hospital. Patients who had at least one neurologic genetic result found in the electronic medical record from 01/01/2014 to 03/01/2023 were included in the study. Variables collected include demographics, health insurance data, and genetic testing results. Results141 patients were included. Most patients were male (51.8%), white (78.0%), and not Hispanic/Latino (96.5%). The mean age at time of genetic testing was 7.9 years. Most patients had Medicaid as their primary insurance (60.3%) as compared to private insurance (39.7%). 215 genetic reports were examined (137 Medicaid charts and 78 private insurance charts). There was no statistically significant difference from mean time lapse between test order date to results date for Medicaid patients (27.3 days) versus private insurance (31.5 days, p=0.40). Molecular genetics testing and epilepsy gene panel order were the most common tests ordered for both Medicaid (86.1%, 37.2%) and private insurance (88.5%, 39.7%, respectively). ConclusionsThe mean time between test order date to results date was comparable between private and Medicaid insured patients. Our results suggest that there is no significant difference for time to result between pediatric neurology patients who carry public versus private insurance for genetic testing.

In silico approximation to aflatoxin B1 metabolism and sensitivity in commercial poultry species based on empirical mathematical equations

Enzyme kinetic parameters for aflatoxin B1 metabolism have been reported for chicken, quail, turkey and duck, but an integrated in silico model has not been proposed. Both enzyme-catalyzed reactions and spontaneous reactions were modeled in the CellDesigner software and results were adjusted to Hill, Rational and Hoerl models. Results revealed that the higher amount of aflatoxin B1 epoxide produced in a short lapse of time and a low production of epoxide conjugated to glutathione explains the severe genotoxic effect of aflatoxin B1 in duck. Also, the higher amount of aflatoxicol produced is time-associated to aflatoxin B1 resistance in chicken. Finally, the cytotoxic effects in quail and duck are caused by a large aflatoxin B1 dialdehyde production in a short period of time.

Explanation for the Absence of Secondary Peaks in Black Hole Light Curve Autocorrelations.

The observed radiation from hot gas accreting onto a black hole depends on both the details of the flow and the spacetime geometry. The lensing behavior of a black hole produces a distinctive pattern of autocorrelations within its photon ring that encodes its mass, spin, and inclination. In particular, the time autocorrelation of the light curve is expected to display a series of peaks produced by light echoes of the source, with each peak delayed by the characteristic time lapse τ between light echoes. However, such peaks are absent from the light curves of observed black holes. Here, we develop an analytical model for such light curves that demonstrates how, even though light echoes always exist in the signal, they do not produce autocorrelation peaks if the characteristic correlation timescale λ_{0} of the source is greater than τ. We validate our model against simulated light curves of a stochastic accretion model ray traced with a general-relativistic code, and then fit the model to an observed light curve for Sgr A^{*}. We infer that λ_{0}>τ, providing an explanation for the absence of light echoes in the time autocorrelations of Sgr A^{*} light curves. Our results highlight the importance for black hole parameter inference of spatially resolving the photon ring via future space-based interferometry.

Could Raman spectroscopy investigate the changes of cell oxidative stress status in thyroid diseases? A pilot study on cytological samples

The incidence of thyroid nodules is rapidly increasing worldwide. Raman spectroscopy (RS) is a powerful label-free and non-invasive technique, successfully used for early stage diagnosis. Here, RS is proposed as a tool to investigate the thyroid disease, including neoplasms, through the study of cell oxidative stress (OS), which represents one of the main cancer risk factors. In this study, we enrolled 28 patients, submitted to a first and second thyroid fine needle aspiration (FNA) during follow up. The cytological samples were studied by RS and morphological examination. Typical Raman spectra of thyroid cytological samples are reported and the contribution of oxidized and reduced cytochrome b and c and carotenoids are discussed. On the basis of the evolution of the Raman features over the time lapse between the two FNAs, the 28 patients have been classified into 4 different categories and the most representative case for each category is reported and discussed in detail. For each category, the different Raman intensity ratio between oxidized and reduced cytochromes b and c is reported and associated to different cell OS status, along with the presence of carotenoids. Overall, our results support a correlation among changes in oxidative stress, carotenoids uptake and thyroid diseases, which could inspire new fundamental research on biomarkers and signaling pathways involved in thyroid OS.

Abstract A084: CDK12 inhibition drives mitotic catastrophe, triggering genome instability and innate immune response in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with limited therapies. In our screening using patient-derived organoids, we identified cyclin-dependent kinase 12 (CDK12) as a promising target in a subset of PDAC. Both pharmacological and genetic inhibition of CDK12 exerted potent antitumor activity in vitro and in vivo, inducing double-strand DNA breaks and apoptosis. CDK12 is a member of cyclin-dependent kinases that is involved in gene expression regulations at multiple levels. Recently, CDK12 has gained attention as a therapeutic target in several types of cancers including triple-negative breast cancer and Ewing sarcoma. However, little is known about the impact and possibility of CDK12 inhibition in pancreatic cancer treatment. As the lack of specific inhibitors that selectively target CDK12, studying CDK12 has long been challenging. To overcome this, we used CRISPR-Cas9 mediated genome editing to generate FKBP12F36V (dTAG) knock-in PDAC cell lines, enabling rapid elimination of endogenous CDK12 using a degrader against dTAG (dTAG-13). Quantitative-image-based cytometry and time lapse imaging showed that CDK12 ablation induces mitotic arrest, DNA damage and apoptosis (mitotic catastrophe). Specifically, loss of CDK12 kinase activity in the S phase was sufficient to slow DNA replication speed, leading to spindle assembly checkpoint activation and mitotic catastrophe. Importantly, cells that escaped mitotic death accumulate micronuclei, triggering immune response signaling that is mediated by the cGAS-STING-type I interferon pathway. Our results suggest that CDK12 is a promising target in a subset of PDAC patients, where CDK12 inhibition exerts antitumor activity both in cell autonomous and non-cell autonomous ways through inducing mitotic catastrophe as well as triggering immune response. Citation Format: Dosuke Iwadate, Keisuke Yamamoto, Hiroyuki Kato, Keisuke Tateishi, Mitsuhiro Fujishiro. CDK12 inhibition drives mitotic catastrophe, triggering genome instability and innate immune response in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A084.

Cladribine use trend in Latin America: the changes in patient profile impact in the drug effectiveness.

Cladribine was approved for Multiple Sclerosis (MS) inour country in 2018. A previous study by our group showed that its use among high efficacy therapiesoptions has been increasing along the years. to analyze the cladribineuse trend across time since its approval. A retrospective cohort study was performed. People withMS (pwMS) treated with cladribinewere included. Two periods were defined: P1 = 2018 - 2020 and P2 = 2021 - 2023. A comparative analysis was carry outbetween P1and P2 to assessthe trend of use, clinical/demographic characteristics, and effectiveness. One hundred ninety- seven people with MS (pwMS) were included, mean EDSS: 2.2 ± 3.08, 72.6% female, mean age: 35.2 ± 9years, mean disease duration: 6.6 ± 5.6years, mean time lapse under cladribine: 26.1 ± 12.4months. Regarding patient profile, we found significant differences between P1 and P2 in the MS evolution (p = 0.001) and EDSS (p = 0.018) prior to initiation of cladribine.In the individualized analysis by year, we found a decrease in relapse number in the year prior to starting cladribine (p = 0.02). Ahigher proportion of No Evidence of Disease Activity (NEDA) was found in patients treated at P2 compared to those treated at P1 (p < 0.001). An earlier use of cladribineachieved a significant increase in reaching NEDA. This learning curve in the use of cladribine allows a better identification of the candidate patient and influences the treatment effectiveness.

Drug resistant pancreatic cancer cells exhibit altered biophysical interactions with stromal fibroblasts in imaging studies of 3D co-culture models

Interactions between tumor and stromal cells are well known to play prominent roles in progression of pancreatic ductal adenocarcinoma (PDAC). As knowledge of stromal crosstalk in PDAC has evolved, it has become clear that cancer associated fibroblasts can play both tumor promoting and tumor suppressive roles through a combination of paracrine crosstalk and juxtacrine interactions involving direct physical contact. Another major contributor to dismal survival statistics for PDAC is development of resistance to chemotherapy drugs, though less is known about how the acquisition of chemoresistance impacts upon tumor-stromal crosstalk. Here, we use time lapse imaging and image analysis to study how co-culture geometry impacts interactions between epithelial and stromal cells. We show that extracellular matrix (ECM) overlay cultures in which stromal cells (pancreatic stellate cells, or normal human fibroblasts) are placed adjacent to PDAC cells (PANC1) result in direct heterotypic cell adhesions accompanied by dramatic fibroblast contractility. We analyze these interactions in co-cultures using particle image velocimetry (PIV) analysis to quantify cell velocities over the course of time lapse movie sequences. We further contrast co-cultures of PANC1 with those containing a drug resistant subline (PANC1-OR) previously established in our lab and find that heterotypic cell–cell interactions are suppressed in the latter relative to the parental line. We use RNA-seq and bioinformatics analysis to identify differential gene expression in PANC1 and PANC1-OR, which shows that negative regulation of cell adhesion molecules, consistent with increased epithelial mesenchymal transition (EMT), is also correlated with reduction in the hetrotypic cell–cell contact necessary for the contractile behavior observed in drug naïve cultures. Overall these findings elucidate the role of drug-resistance in inhibiting an avenue of stromal crosstalk which is associated with tumor suppression and also help to establish cell culture conditions useful for further mechanistic investigation.

SARS-COV-2 breakthrough infection and its covariates among healthcare providers of a hospital in Bangladesh during the omicron wave

IntroductionBreakthrough infection by SARS-COV-2 virus among vaccinated individuals has been reported from all over the world and it has created a substantial challenge in designing strategies to live with the virus in the post-pandemic era. Factors affecting the extent and nature of breakthrough infection are still not fully understood and those are known to vary depending on host and agent factors. Health Care Workers (HCWs), especially in hospital settings, are front-liners in combating the epidemic and, consequently, they are more vulnerable to breakthrough infection by SARS-COV-2. Like most of the countries of the world, Bangladesh went through several waves of COVID-19 and the last (3rd wave) was the widespread Omicron wave during the winter of 2022. HCWs in Bangladesh have been disproportionately affected by the virus. Under this context, the aim of the present study was to explore breakthrough infection (BTI) and its host-related covariates among HCWs of a COVID-dedicated city-based hospital during the Omicron wave in Bangladesh. Materials and methodsAn observational cross-sectional study was conducted on 267 HCWs of the Narayanganj Tertiary (300-bed) hospital during February–March 2022 which coincided with the terminal part of the 3rd wave. Data were collected by trained Field Assistants using Interviewer-administered Data Collection Forms with Questionnaires as instruments. Previous COVID-19 status (any time after the onset of the pandemic and within last 3 months) was explored by the history of specific symptoms as well as by the confirmatory rtPCR test reports from DGHS approved laboratories Anti-nucleocapsid antibody (Anti-N-Ab) in venous blood samples, assayed by a chemiluminescent ELISA technique, was used as a seroprevalence-based marker of breakthrough infection during the preceding few months. Data were analyzed by bivariate as well as multivariate statistics using the IBM-SPSS software. ResultsThe median age (range) of the HCWs was 38 (21–65) years; Body Mass Index (BMI, kg/m2) 25 (15–49); and Waist-Hip Ratio (WHR) was 0.92 (0.46–1.21). The male subjects had significantly higher median age (p = 0.01) and higher WHR (p = 0.001) as compared to the female subjects. As per the BMI category, subjects with overweight and obesity constituted 83.3 % of the male subjects as compared to 61.6 % of the female subjects (p = 0.001). The time lapse between receiving of 3rd dose and blood sampling was significantly higher among females compared to males (median days 60 vs 49, p < 0.02) indicating earlier vaccination with 1st booster dose among females. A proportion of 51.85 % male and 49.68 % female subjects showed Anti-N-Ab positivity; there was no significant difference between the gender groups. Also, there was no significant difference among male and female subjects regarding the Ab levels. On Spearman correlation analysis, a tendency of association of WHR with Ab level was observed among the male subjects; however, the association did not show statistical significance (p = 0.09). On binary logistic regression Ab positivity was found to be independently associated with WHR (p = 0.03), and prior SARS-COV-2 infection within the last 3 months (p = 0.02) among males. When all the subjects were considered together, COVID symptom positivity during the last 3 months (p = 0.067) and receiving the 1st booster dose (p = 0.07) showed a tendency of association with Ab positivity. On multiple regression analysis, Ab levels showed a negative association with WHR (p = 0.035) among males. ConclusionsMore than 50 % of the vaccinated hospital-based HCWs in Bangladesh suffered from BTI during the winter of 2022 when the Omicron wave (the 3rd wave) of COVID-19 was at its peak. The data also indicate that overweight and obesity are major host-related risk factors underlying BTI. Inadequate coverage by a booster dose seems to be another determinant of BTI and the level of immune response in this population.

Aspekti prikladnosti trostupanjskog miješanja gotove betonske smjese

Several studies have indicated that three-stage mixing (TM) methods improve the mechanical strength and slump of concrete compared to those of normal mixing methods, particularly when a recycled concrete aggregate is used. However, most studies did not address the technological aspects of ready-mixed concrete, including continuous mixing during site delivery. In this study, the properties of concrete (slump and compressive strength) based on the time lapse after mixing via the TM method (i.e. immediately, 45 min, and 90 min after mixing) were investigated, and the samples were tested after three years of curing. The results indicate some positive effects of TM on ready-mixed concrete and its characteristics on a delivery to the construction site, particularly a less severe loss of consistency compared to that of conventional mixing, as well as a positive effect on the compressive strength when fly ash is used as an aggregate coating additive in the first stage of concrete mixing.

First impressions vs. The Peak-End Rule: Episodic evaluations in a service experience and the moderating effect of retrospective delay

This article integrates prior research on episodic evaluations with the service experience literature to investigate the impact of multiple interactions with frontline employees on customer evaluations of the employees and overall satisfaction with the service experience. A field study was constructed of customer interactions with hotel staff, including over 5,000 customer stays across a 5-year period. The results reveal that key moments, specifically the first impression, peak impressions, and last impressions, significantly impact satisfaction with the overall hotel stay. Moreover, we also introduce a new construct, retrospective delay, which is the time lapse between the actual service experience and the evaluation of the experience. In doing so, unlike prior research indicating the robustness of the peak-end rule, our results find that first impressions are the most important contributor to frontline employee evaluations and overall satisfaction. Furthermore, we find that first impressions become more critical as retrospective delay increases. Our results suggest that first impressions not only impact frontline employee evaluations and satisfaction with the service encounter, but that measurement timing could explain some conflicting findings in the services literature regarding the efficacy of positive starts.

Visual input regulates melanophore differentiation.

Developmental processes continue in organisms in which sensory systems have reached functional maturity, however, little research has focused on the influence of sensory input on cell and tissue development. Here, we explored the influence of visual system activity on the development of skin melanophores in Xenopus laevis. Melanophore number was measured in X. laevis larvae after the manipulation of visual input through eye removal (enucleation) and/or incubation on a white or black substrate at the time when the visual system becomes functional (stage 40). To determine the developmental process impacted by visual input, migration, proliferation and differentiation of melanophores was assessed. Finally, the role of melatonin in driving melanophore differentiation was explored. Enucleating, or maintaining stage 40 larvae on a black background, results in a pronounced increase in melanophore number in the perioptic region within 24 h. Time lapse analysis revealed that in enucleated larvae new melanophores appear through gradual increase in pigmentation, suggesting unpigmented cells in the perioptic region differentiate into mature melanophores upon reduced visual input. In support, we observed increased expression of melanization genes tyr, tyrp1, and pmel in the perioptic region of enucleated or black background-reared larvae. Conversely, maintaining larvae in full light suppresses melanophore differentiation. Interestingly, an extra-pineal melatonin signal was found to be sufficient and necessary to promote the transition to differentiated melanophores. In this study, we found that at the time when the visual system becomes functional, X. laevis larvae possess a population of undifferentiated melanophores that can respond rapidly to changes in the external light environment by undergoing differentiation. Thus, we propose a novel mechanism of environmental influence where external sensory signals influence cell differentiation in a manner that would favor survival.

Scarabaeolus carniphilus: a necrophagous dung beetle (Coleoptera: Scarabaeinae) buries and feeds on a dead snake

A rare sighting of two male carrion specialist dung beetles, Scarabaeolus carniphilus Deschodt &amp; Davis, 2015, burying a freshly dead Herald snake (Crotaphopeltis hotamboeia (Laurenti, 1768)) is documented from its discovery in the field and subsequent reburial under laboratory conditions. The species studied is a member of the telecoprid (dung roller) Scarabaeini, but behaved here like a paracoprid; it deliberately cut into and removed flesh from the dead snake; these pieces were then taken into a feeding burrow; later a pheromone release stance was taken up near an established burrow; and under laboratory conditions the snake was completely buried. These observations, mostly novel for this species and its genus are clearly documented via photographs and an online time lapse video taken every hour for 24-hours during the snake’s-(re)burial. This note introduces relevant aspects of dung beetle natural history and new biological information for Scarabaeolus and particularly for Sc. carniphilus. It records and interprets a carrion specialist Scarabaeini dung beetle burying and feeding on fresh carrion; highlights natural history findings (pheromone release) previously not considered for the evolution of the Scarabaeini; and aims to stimulate behavioural research into this interesting and under studied genus Scarabaeolus.