1,130 research outputs found
Experimental Control and Characterization of Autophagy in Drosophila
Insects such as the fruit fly Drosophila melanogaster, which fundamentally reorganize their body plan during metamorphosis, make extensive use of autophagy for their normal development and physiology. In the fruit fly, the hepatic/adipose organ known as the fat body accumulates nutrient stores during the larval feeding stage. Upon entering metamorphosis, as well as in response to starvation, these nutrients are mobilized through a massive induction of autophagy, providing support to other tissues and organs during periods of nutrient deprivation. High levels of autophagy are also observed in larval tissues destined for elimination, such as the salivary glands and larval gut. Drosophila is emerging as an important system for studying the functions and regulation of autophagy in an in vivo setting. In this chapter we describe reagents and methods for monitoring autophagy in Drosophila, focusing on the larval fat body. We also describe methods for experimentally activating and inhibiting autophagy in this system and discuss the potential for genetic analysis in Drosophila to identify novel genes involved in autophagy
Short interpregnancy interval and its predictors in Ethiopia: implications for policy and practice.
Introduction: interpregnancy interval (IPI) is the time elapsed between the birth of one live child and the conception of subsequent pregnancies. Several studies in Ethiopia indicated a high prevalence of a short interbirth interval - a proxy indicator of IPI. However, these studies were prone to selection bias as they did not include women who did not go on to have another pregnancy. Therefore, this study estimated the incidence of short IPI (< 24 months) and its risk factors among women who had at least one child in Ethiopia.
Methods: we used a retrospective analysis of a cross-sectional study from the nationally representative Ethiopian Mini Demographic and Health Survey (EMDHS) conducted in 2019. The event was defined as the conception of the subsequent pregnancy within 24 months following the last child. A weighted Cox Proportional Hazard model was used to estimate the adjusted hazard ratios (aHR) and 95% confidence intervals (CIs).
Results: the incidence of short IPI was 6%. Rural residence, being young age, low educational attainment, having the last child died and having female last birth were the risk factors for short IPI. However, having higher parity, attending Antenatal Care (ANC) visits, being delivered at a health facility, and receiving Postnatal Care (PNC) visits were the protective factors for short IPI.
Conclusion: the incidence of short IPI in Ethiopia was considerable. Sociodemographic and health service-related factors determine the short IPI. Hence, considering the immediate and long-term health and socioeconomic consequences of short IPI, the Ethiopian government should implement holistic and multisectoral interventions
Field effects studies in the Chernobyl Exclusion Zone: lessons to be learnt
In the initial aftermath of the 1986 Chernobyl accident there were detrimental effects recorded on wildlife, including, mass mortality of pine trees close to the reactor, reduced pine seed production, reductions in soil invertebrate abundance and diversity and likely death of small mammals.
More than 30 years after the Chernobyl accident there is no consensus on the longer-term impact of the chronic exposure to radiation on wildlife in what is now referred to as the Chernobyl Exclusion Zone. Reconciling this lack of consensus is one of the main challenges for radioecology. With the inclusion of environmental protection in, for instance, the recommendations of the International Commission on Radiological Protection (ICRP), we need to be able to incorporate knowledge of the potential effects of radiation on wildlife within the regulatory process (e.g. as a basis on which to define benchmark dose rates).
In this paper, we use examples of reported effects on different wildlife groups inhabiting the Chernobyl Exclusion Zone (CEZ) as a framework to discuss potential reasons for the lack of consensus, consider important factors influencing dose rates organisms receive and make some recommendations on good practice
Some problems in the study of the chronology of the ancient nomadic cultures in Eurasia (9th - 3rd centuries BC)
This research is focused on the chronological investigations of ancient nomads belonging to the Scythian cultures which occupied the steppe and forest-steppe zones of Eurasia during the 9th-3rd centuries BC. The 14C dates for the pre-scythian and early scythian time in both Europe and Asia are presented and compared to their chronological position based on archaeological evidence. The first 14C dates have been produced for the Scythian time monuments located in the Lower Volga River basin, Urals and Transurals regions. Their chronological positions are compared with the position of the monuments of Southern Siberia and Central Asia. It was shown that the nomadic cultures belonging to the Scythian culture began to exist over the wide territory of Eurasia from the 9th-8th centuries cal BC and there are some monuments which may be synchronous to the Arzhan royal barrow (the oldest monument known). A list of new 14C dates and a map of the monuments are presented
A chronology of the Scythian antiquities of Eurasia based on new archaeological and C-14 data
The paper is compares the chronology of the monuments of the Scythian epoch located in the east and west of the Eurasian steppe zone on the basis of both archaeological and radiocarbon data. The lists of C-14 dates for the monuments located in different parts of Eurasia are presented according to the periods of their existence. Generally, the C-14 dates are confirmed the archaeological point of view and allow us to compare the chronological position of the European and Asian Scythian monuments on the united C-14 time scale
Psychoeducational intervention for people at high risk of developing another melanoma: a pilot randomised controlled trial
Introduction Information and psychological needs have been reported as one of the greatest areas of unmet needs for patients with melanoma. To respond to these needs, we developed the Melanoma Care Intervention, a developed psychoeducational intervention for people at high risk of developing another melanoma comprising of a newly developed melanoma educational booklet and individually tailored telephone support sessions provided by trained psychologists. The purpose of this study was to investigate the acceptability and feasibility of the Melanoma Care Intervention.
Methods Twenty-four adults (14 men, 10 women, mean age: 58 years, SD: 12.2) at high risk of developing a subsequent primary melanoma were recruited and randomly assigned 1:1 to the intervention (a psychoeducational booklet, a Cancer Council booklet on melanoma and up to five telephone-based sessions with a psychologist) or usual care (Cancer Council booklet only). Acceptability, feasibility, fear of cancer recurrence and secondary psychosocial outcomes were assessed at baseline, 1 and 6 months.
Results Satisfaction and perceived benefits were rated highly for all intervention components, particularly the telephone-based psychology sessions (mean satisfaction and benefits: both 9.27 out of 10, SD=2.41). The quality of information and support provided throughout the trial was rated as ‘high’ by the intervention group, with a mean score of 4.6 out of a possible 5 (SD=0.9) and 4.2 (SD=1.2) for the control group.
Conclusions The intervention was feasible and acceptable for improving psychological adjustment. Timely access to effective, evidence-based, psychological care is a recognised need for people with melanoma. The intervention is designed to directly address this need in a way that is feasible in a clinical setting, acceptable to patients and health professionals
Cluster Masses Accounting for Structure along the Line of Sight
Weak gravitational lensing of background galaxies by foreground clusters
offers an excellent opportunity to measure cluster masses directly without
using gas as a probe. One source of noise which seems difficult to avoid is
large scale structure along the line of sight. Here I show that, by using
standard map-making techniques, one can minimize the deleterious effects of
this noise. The resulting uncertainties on cluster masses are significantly
smaller than when large scale structure is not properly accounted for, although
still larger than if it was absent altogether.Comment: 5 pages, 5 figure
Operating characteristics of the spinning cone column
OBJECTIVE: To establish whether uniparental disomy (UPD) could represent an outcome of embryonic aneuploidy self-correction and its relevance to preimplantation genetic diagnosis, and to validate a method of UPD detection in limited quantities of cells and determine the frequency of UPD in a large sample size of human blastocysts. DESIGN: Retrospective observational. SETTING: Academic center for reproductive medicine. PATIENT(S): Couples undergoing in vitro fertilization (IVF) treatment whose embryos underwent trophectoderm biopsy single-nucleotide polymorphism (SNP) array-based 24-chromosome aneuploidy screening. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Rate of UPD observed in the human blastocyst. RESULT(S): After application of defined thresholds, 2 of 3,401 blastocysts were found to possess isodisomy, and 0 were found to possess heterodisomy. The overall frequency of UPD in the human blastocyst was therefore 0.06%. CONCLUSION(S): This validated method of detection indicates that UPD is extremely rare and suggests that routine screening during preimplantation genetic diagnosis (PGD) may not be necessary. Furthermore, chromosomal UPD is unlikely to explain or support the existence of embryonic self-correction
Deterministic and stochastic descriptions of gene expression dynamics
A key goal of systems biology is the predictive mathematical description of
gene regulatory circuits. Different approaches are used such as deterministic
and stochastic models, models that describe cell growth and division explicitly
or implicitly etc. Here we consider simple systems of unregulated
(constitutive) gene expression and compare different mathematical descriptions
systematically to obtain insight into the errors that are introduced by various
common approximations such as describing cell growth and division by an
effective protein degradation term. In particular, we show that the population
average of protein content of a cell exhibits a subtle dependence on the
dynamics of growth and division, the specific model for volume growth and the
age structure of the population. Nevertheless, the error made by models with
implicit cell growth and division is quite small. Furthermore, we compare
various models that are partially stochastic to investigate the impact of
different sources of (intrinsic) noise. This comparison indicates that
different sources of noise (protein synthesis, partitioning in cell division)
contribute comparable amounts of noise if protein synthesis is not or only
weakly bursty. If protein synthesis is very bursty, the burstiness is the
dominant noise source, independent of other details of the model. Finally, we
discuss two sources of extrinsic noise: cell-to-cell variations in protein
content due to cells being at different stages in the division cycles, which we
show to be small (for the protein concentration and, surprisingly, also for the
protein copy number per cell) and fluctuations in the growth rate, which can
have a significant impact.Comment: 23 pages, 5 figures; Journal of Statistical physics (2012
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