Transitory Population Research Articles

Neural crest development and disorders: from patient to model system and back again - the NEUcrest conference.

The neural crest (NC) is an embryonic multipotent and transitory population of cells that appears during late gastrulation/early neurulation in the developing embryos of vertebrate organisms. Often called "the fourth germ layer", the NC is characterised by incredible mobility, which allows the NC cells to migrate throughout the whole embryo, giving rise to an astonishing number of different derivatives in the adult organism, such as craniofacial skeleton, adrenal gland, enteric nervous system and melanocytes. Because of these properties, neurocristopathies (NCPs), which is the term used to classify genetic diseases associated with NC developmental defects, are often syndromic and, taken all together, are the most common type of genetic disease. The NEUcrest consortium is an EU funded innovative training network (ITN) that aims to study the NC and NCPs. In March 2024, the early stage researchers (ESRs) in the NEUcrest consortium organised an in-person conference for well-established and early career researchers to discuss new advances in the NC and NCPs field, starting from the induction of the NC, and then moving on to migration and differentiation processes they undergo. The conference focused heavily on NCPs associated with each of these steps. The conference also included events, such as a round table to discuss the future of the NC research, plus a talk by a person living with an NCP. This 3-day conference aimed to bring together the past, present and future of this field to try and unravel the mysteries of this unique cell population.

A75 PEDIATRIC ABDOMINAL PAIN PRESENTING TO A HOSPITAL-BASED GI CLINIC: EVOLUTION AND DISPOSITION

Abstract Background Abdominal pain accounts for 50% of pediatric gastroenterology consultations. While data exists on the possible etiologies of abdominal pain, there is a paucity of data on the natural evolution of abdominal pain while under the care of a Pediatric Gastroenterologist. Given limited access to Pediatric Gastroenterologists and long waiting times for initial consultation for abdominal pain, understanding what interventions ameliorate pain may help Gastroenterologists advise referring physicians while the patient awaits a consultation. Aims Primary outcome measure was the percentage of patients who reported at least a 75% subjective improvement of pain over baseline consultation. Methods A retrospective chart review between April 2014 and Dec 31, 2022 was taken in a hospital based GI clinic. Subjects referred for assessment of abdominal pain were identified, along with subjects referred for reflux and dysphagia as a comparator group. Subsequent visits were abstracted to identify diagnosis disposition and assess which interventions were tried and to what extent they succeeded. Patient loss to follow up were also measured. Results were summarized using descriptive statistics, and regression modeling will be attempted to identify predictors of response. Results 393 subjects were referred for abdominal pain and 286 for GERD and dysphagia. 439 (64.7%) reported at least 75% improvement in symptoms. 242 (35.6%) underwent endoscopy, 263 (38.7%) used Proton Pump Inhibitors, and 38 (8.54%) used Polyethylene Glycol-3350. Carbohydrate eliminations of various types were used in 13.5 - 27% of subjects with pain. 193 subjects (28.5%) were ultimately lost to follow up though some did report improvement in symptoms. Only 45 (6.6%) remained in active care by the end of the study while only 13 (1.93%) were transitioned to an Adult Gastroenterologist at 18 years old. Conclusions Pediatric Abdominal Pain is primarily a transitory population in the Pediatric GI clinic, with a large number responding to successive interventions. There is also a sizable minority who are lost to follow up. Future studies should attempt to identify the reasons for loss to follow up and ultimate disposition. Funding Agencies William Osler Health System Summer Student Research Program

A prospective multi-centre observational cohort study to evaluate frequency, management and outcomes of acute severe (grade III-VI) acromioclavicular joint injuries in the United Kingdom.

To collect data on current management and outcome of acute severe acromioclavicular joint (ACJ) injuries to inform the knowledge base, design and conduct of future research and explore the patient and injury features predicting surgical management. A prospective cohort study was conducted by two trainee collaboratives of acute Grade III to VI ACJ injuries presenting to 12 hospital trusts. 54 Patients were recruited within four weeks of injury regardless of treatment type over a one-year period. Patient reported outcomes and healthcare resource use were collected at six and 12 months post injury. Accounting for Rockwood grade, age, gender and dominant arm injury, the operative group had a statistically lower Oxford Shoulder Score (OSS) at baseline (10.8 vs 25.3, <0.0001) and at six months (37 vs 43.8, p = 0.024) than the non-operative group. There was no statistical difference at 12 months (40 vs 44, p = 0.205). The odds of operative management were inversely correlated with baseline OSS (OR 0.89, p = 0.014). There was no clear preferential method of fixation in the ten patients that received surgery. Future research needs to take into consideration the transitory population of working age, on response to follow up. A future randomised clinical trial (RCT) should be multicentred, pragmatic and stratified for baseline function and injury grade at randomisation.

\u2018Where does water go\u2019? A critical analysis of nature of water crisis in Darjeeling city, India

Water crisis is such a phenomenon that almost every city experiences to some extent these days. Nature, dimensions, and impact of the crisis vary based on spatial diversity. This article attempts to critically analyse the nature of water crisis and to find out the reasons behind such crisis in Darjeeling city. The city’s public water supply is mainly controlled by the municipal authority, and water is supplied from the Senchal lakes. The centralised system, developed by the British in the early nineteenth century, is not sufficient for the entire city at present, and not affordable for all classes as well. Primarily the scarcity emerged due to the city’s population growth, and the city’s changing commercial nature, especially the booming tourism sector. And the age-old water infrastructure cannot cope with the fast-growing demand for water. Moreover, still now municipal authority does not consider a large number of transitory population, while calculating the water demand. Massive gap exists between the actual water scarcity observed in the field and the scarcity shown in the official data. Therefore, a reconsideration of municipal water budget is required to manage water resources and services sustainably. Using both the quantitative and qualitative methods, this empirical study critically assesses the existing gap between demand and supply, and also explores the process of illegal flow of water thus making the scarcity even more intense. It argues for fair and active water governance to minimise the demand–supply gap, and active community participation to ensure water justice to the commons.

Urban environment and sustainable water supply: a comprehensive analysis of Darjeeling city, India

This article is an attempt to analyse the link between the condition of city environment and availability of water in Darjeeling city. Darjeeling, located in the Eastern Himalayan Region of India, is such a city which faces acute water scarcity in most part of the year, except during monsoon. The city cannot use ground water directly, and there is no river as source of water as well. It only uses spring water and rain water. The climatic condition and local environmental conditions have higher control over the availability of daily water. This article analyses the city’s 100-year climatic conditions as well as the condition of vegetation cover and built-up areas using NDVI and BUI methods, respectively. The present study explores that the deterioration of natural environmental conditions and increasing demand from both the permanent population and transitory population accelerate the intensity of water scarcity. Measuring the fluctuation of discharge (during pre-monsoon and post-monsoon period), the paper discusses how except in monsoon, most of the spring’s discharge gets reduced and increases the level of water stress in the city. Using quantitative methods, this empirical study explores that the loss of vegetation and haphazard constructions have enormous impact on the fragile hill ecosystem and reduce the rate of infiltration of water in the sub-surface zones, thus reducing the discharge ultimately. Therefore, the study recommends immediate actions to protect the city environment and to revive those springs for the city’s water security.

Immunophenotype of Vestibular Schwannomas.

Vestibular schwannomas exhibit a uniquely variable natural history of growth, stability, or even spontaneous regression. We hypothesized that a transitory population of immune cells, or immunomodulation of tumors cells, may influence the growth pattern of schwannomas. We therefore sought to characterize the impact of the immune microenvironment on schwannoma behavior. Forty-eight vestibular schwannomas with preoperative magnetic resonance imaging and 11 with serial imaging were evaluated for presence of immune infiltrates (including the pan-leukocyte marker Cluster of Differentiation (CD)45, CD4 and CD8 T-cell, and CD68 and CD163 macrophages) as well as expression of immunomodulatory regulators (Programmed Death Ligand 1 (PD-L1), Programmed Death Ligand 2 (PD-L2), LAG-3, TIM-3, V-domain Ig Suppressor of T cell Activation). Maximal diameter, volume, and recurrence were annotated. Vestibular schwannomas were characterized by diverse signatures of tumor infiltrating leukocytes and immunomodulatory markers. The median tumor volume was 4.7 cm (Interquartile Range (IQR) 1.0-13.0) and maximum diameter was 2.3 cm (IQR 1.5-3.2). Among tumors with serial imaging, the median volumetric growth was 0.04 cm/mo (IQR 0.01-0.18). Tumor volume and maximum diameter demonstrated strong concordance (R = 0.90; p < 0.001). Vestibular schwannoma volume was positively associated with CD4, CD68, and CD163, but not CD8, immune infiltration (all p < 0.05). Tumor growth was positively associated with CD163 and PD-L1 (both p < 0.05). Further, CD163 modified this effect: the relationship between PD-L1 and growth strengthened with increasing CD163 infiltration (R = 0.81, p = 0.007). No other immune cell types modified this relationship. These associations were inconsistently observed for maximum diameter and linear growth. Vestibular schwannomas demonstrate variable expression of immune regulatory markers as well as immune infiltrates. Tumor size is associated with immune infiltrates and tumor growth is associated with PD-L1, especially in the presence of M2-subtype macrophages. Volumetric measures may associate with the biological signature more accurately than linear parameters. Future exploration of the role of immune modulation in select schwannomas will further enhance our understanding of the biology of these tumors and suggest potential therapeutic avenues for control of tumor growth.

Proliferating Transitory T Cells with an Effector-like Transcriptional Signature Emerge from PD-1+ Stem-like CD8+ T Cells during Chronic Infection

T cell dysfunction is a characteristic feature of chronic viral infection and cancer. Recent studies in chronic lymphocytic choriomeningitis virus (LCMV) infection have defined a PD-1+ Tcf-1+ CD8+ Tcell subset capable of self-renewal and differentiation into more terminally differentiated cells that downregulate Tcf-1 and express additional inhibitory molecules such as Tim3. Here, we demonstrated that expression of the glycoprotein CD101 divides this terminally differentiated population into two subsets. Stem-like Tcf-1+ CD8+ Tcells initially differentiated into a transitory population of CD101-Tim3+ cells that later converted into CD101+ Tim3+ cells. Recently generated CD101-Tim3+ cells proliferated invivo, contributed to viral control, and were marked by an effector-like transcriptional signature including expression of the chemokine receptor CX3CR1, pro-inflammatory cytokines, and granzyme B. PD-1pathway blockade increased the numbers of CD101-Tim3+ CD8+ Tcells, suggesting that these newly generated transitional cells play a critical role in PD-1-based immunotherapy.

Space–Time Analysis of Vehicle Theft Patterns in Shanghai, China

To identify and compare the space–time patterns of vehicle thefts and the effects of associated environmental factors, this paper conducts a case study of the Pudong New Area (PNA), a major urban district in Shanghai, China’s largest city. Geographic information system (GIS)-based analysis indicated that there was a stable pattern of vehicle theft over time. Hotspots of vehicle theft across different time periods were identified. These data provide clues for how law enforcement can prioritize the deployment of limited patrol and investigative resources. Vehicle thefts, especially those of non-motor vehicles, tend to be concentrated in the central-western portion of the PNA, which experienced a dramatic rate of urbanization and has a high concentration of people and vehicles. Important factors contributing to vehicle thefts include a highly mobile and transitory population, a large population density, and high traffic volume.

Mental health interventions for children in foster care: A systematic review

Children in foster care have high rates of adverse childhood experiences and are at risk for mental health problems. These problems can be difficult to ameliorate, creating a need for rigorous intervention research. Previous research suggests that intervening with children in foster care can be challenging for several reasons, including the severity and complexity of their mental health problems, and challenges engaging this often transitory population in mental health services. The goal of this article was to systematically review the intervention research that has been conducted with children in foster care, and to identify future research directions. This review was conducted on mental health interventions for children, ages 0 to 12, in foster care, using ERIC, CINAHL, PsycINFO, PubMed, ProQuest's Dissertation and Theses Database, Social Services Abstracts, and Social Work Abstracts. It was restricted to interventions that are at least “possibly efficacious” (i.e., supported by evidence from at least one randomized controlled trial). Studies were evaluated for risk of bias. Ten interventions were identified, with diverse outcomes, including mental health and physiological. Six interventions were developed for children in foster care. Interventions not developed for children in foster care were typically adapted to the foster context. Most interventions have yet to be rigorously evaluated in community-based settings with children in foster care. Little research has been conducted on child and family engagement within these interventions, and there is a need for more research on moderators of intervention outcomes and subgroups that benefit most from these interventions. In addition, there is no consensus regarding how to adapt interventions to this population. Future research should focus on developing and testing more interventions with this population, rigorously evaluating their effectiveness in community-based settings, determining necessary adaptations, and identifying which interventions work best for whom.

Global transcriptional analysis of primitive thymocytes reveals accelerated dynamics of T cell specification in fetal stages

T cell development constitutes a multistage process allowing the dissection of events resulting in cellular commitment and functional specification in a specialized microenvironment. This process is guided by the appropriate expression of regulatory genetic factors like transcriptional activators or repressors which are, in part, dependent on instructive signals of the microenvironment. To date, it remains unclear whether exactly the same genetic mechanism acts in adult compared to fetal T cell development. In order to directly compare T cell commitment during adult and fetal differentiation, we isolated subsequent stages of intrathymic subpopulations starting with early canonical T cell progenitors up to irreversibly committed T cell precursors. The genome-wide analysis revealed several distinct gene clusters with a specific pattern of gene regulation for each subset. The largest cluster contained genes upregulated after transition through the most primitive pool into the next transitory population with a consistently elevated expression of elements associated with ongoing T cell fate specification, like Gata3 and Tcf7, in fetal progenitors. Furthermore, adult and fetal T cell progenitors occupied distinct “transcriptional territories” revealing a precise land map of the progression to final T cell commitment operating in different developmental windows. The presence and/or elevated expression of elements associated with an ongoing establishment of a T cell signature in the most primitive fetal subset is highly suggestive for an extrathymic initiation of T cell specification and underlines the fundamental differences in fetal versus adult lymphopoiesis.Electronic supplementary materialThe online version of this article (doi:10.1007/s00251-012-0620-6) contains supplementary material, which is available to authorized users.

New 3D thermal evolution model for icy bodies application to trans-Neptunian objects

Context. Thermal evolution models have been developed over the years to investigate the evolution of thermal properties based on the transfer of heat fluxes or transport of gas through a porous matrix, among others. Applications of such models to trans-Neptunian objects (TNOs) and Centaurs has shown that these bodies could be strongly differentiated from the point of view of chemistry (i.e. loss of most volatile ices), as well as from physics (e.g. melting of water ice), resulting in stratified internal structures with differentiated cores and potential pristine material close to the surface. In this context, some observational results, such as the detection of crystalline water ice or volatiles, remain puzzling. Aims. In this paper, we would like to present a new fully three-dimensional thermal evolution model. With this model, we aim to improve determination of the temperature distribution inside icy bodies such as TNOs by accounting for lateral heat fluxes, which have been proven to be important for accurate simulations. We also would like to be able to account for heterogeneous boundary conditions at the surface through various albedo properties, for example, that might induce different local temperature distributions. Methods. In a departure from published modeling approaches, the heat diffusion problem and its boundary conditions are represented in terms of real spherical harmonics, increasing the numerical efficiency by roughly an order of magnitude. We then compare this new model and another 3D model recently published to illustrate the advantages and limits of the new model. We try to put some constraints on the presence of crystalline water ice at the surface of TNOs. Results. The results obtained with this new model are in excellent agreement with results obtained by different groups with various models. Small TNOs could remain primitive unless they are formed quickly (less than 2 Myr) or are debris from the disruption of larger bodies. We find that, for large objects with a thermal evolution dominated by the decay of long-lived isotopes (objects with a formation period greater than 2 to 3 Myr), the presence of crystalline water ice would require both a large radius (>300 km) and high density (>1500 kg m −3 ). In particular, objects with intermediate radii and densities would be an interesting transitory population

A systematic review and meta-analysis of the psychosis continuum: evidence for a psychosis proneness–persistence–impairment model of psychotic disorder

A systematic review of all reported incidence and prevalence studies of population rates of subclinical psychotic experiences reveals a median prevalence rate of around 5% and a median incidence rate of around 3%. A meta-analysis of risk factors reveals associations with developmental stage, child and adult social adversity, psychoactive drug use, and also male sex and migrant status. The small difference between prevalence and incidence rates, together with data from follow-up studies, indicates that approximately 75-90% of developmental psychotic experiences are transitory and disappear over time. There is evidence, however, that transitory developmental expression of psychosis (psychosis proneness) may become abnormally persistent (persistence) and subsequently clinically relevant (impairment), depending on the degree of environmental risk the person is additionally exposed to. The psychosis proneness-persistence-impairment model considers genetic background factors impacting on a broadly distributed and transitory population expression of psychosis during development, poor prognosis of which, in terms of persistence and clinical need, is predicted by environmental exposure interacting with genetic risk.

Inferring population history from microsatellite and enzyme data in serially introduced cane toads, Bufo marinus.

Much progress has been made on inferring population history from molecular data. However, complex demographic scenarios have been considered rarely or have proved intractable. The serial introduction of the South-Central American cane toad Bufo marinus in various Caribbean and Pacific islands involves four major phases: a possible genetic admixture during the first introduction, a bottleneck associated with founding, a transitory population boom, and finally, a demographic stabilization. A large amount of historical and demographic information is available for those introductions and can be combined profitably with molecular data. We used a Bayesian approach to combine this information with microsatellite (10 loci) and enzyme (22 loci) data and used a rejection algorithm to simultaneously estimate the demographic parameters describing the four major phases of the introduction history. The general historical trends supported by microsatellites and enzymes were similar. However, there was a stronger support for a larger bottleneck at introductions for microsatellites than enzymes and for a more balanced genetic admixture for enzymes than for microsatellites. Very little information was obtained from either marker about the transitory population boom observed after each introduction. Possible explanations for differences in resolution of demographic events and discrepancies between results obtained with microsatellites and enzymes were explored. Limits of our model and method for the analysis of nonequilibrium populations were discussed.

A transitory population of substance P-like immunoreactive neurones in the developing cerebral cortex of the mouse

Immunocytochemical methods were used to investigate the developmental expression of substance P (SP) in mouse cerebral cortex. SP-like-immunoreactive cells were first detected at postnatal day 0 (PO), their numbers being notably increased by P2. Immunopositive cells were especially abundant in layer VIb and in the subjacent future white matter, although they were also present in layer V. Between P5 and P8 the number of SP-like-immunoreactive cells gradually decreased, being almost completely absent by P12. At these stages cells were only observed in the deepest cortical layers. From P16 onwards, the adult pattern of SP-like immunoreactivity emerged with a few immunopositive cells scattered throughout the cortical layers. The present data show a transitory population of SP-like-immunoreactive cells present in the mouse cerebral cortex during the first postnatal week. On the basis of close correlations of SP-like expression with the distribution or transitory populations and the timing of cell death in rodents, we propose that most of the SP-like-immunoreactive cells reported here would probably disappear by cell death.

Transitory population of cells in the temporal cortex of kittens

A correlated study, using conventional electron microscopy and the Golgi method in the subplate layer and lower part of layer VI, in the developing temporal cortex of kittens has been made. Neuronal death was identified in semithin sections and with the electron microscope. The existence of presumptive degenerating cells in Golgi preparations has been suggested. This transitory population of early-generated subplate cells might be involved in the organization of cortical afferents before the final targets have completed their migrations.

Changes in surface markers of human monocytes following their in vitro maturation to macrophages.

Peripheral blood monocytes are a transitory population between bone marrow promonocytes and tissue macrophages (1,2). Blood monocytes have several characteristics which assign them to the macrophage lineage. However, each of the macrophage markers is not always expressed on the entire monocyte population (3,4) and some markers and functions are altered during monocyte maturation or activation (5,6,7). In vitro cultivation of human monocytes is accompanied by a series of changes which results in their transition to macrophages (8). In the present study, we analyzed membrane markers on freshly obtained monocytes and on mature macrophages. These were the receptor for peanut agglutinin (PNA), which is associated with cell maturation in T lymphocytes (9) and the HLA-DR which is associated with some immune functions (10–12).

Skeletal polymorphism and genetic drift in a Delhi frog, Rana cyanophlictis.

Nineteen axial skeletal variants are described in the frog Rana cyanophlictis, collected from five isolated populations of Delhi. Four of these populations came from large perennial ponds and one, a transitory population, was entrapped from a temporary rain pool. The populations were found to diverge significantly from each other in the incidence of these skeletal variants. We have attributed this divergence to genetic drift, but the effects of unknown selective forces cannot be ruled out.