Malaria parasite egress at a glance Tan, Michele S Y; Blackman, Michael J
Journal of cell science,
03/2021, Letnik:
134, Številka:
5
Journal Article
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All intracellular pathogens must escape (egress) from the confines of their host cell to disseminate and proliferate. The malaria parasite only replicates in an intracellular vacuole or in a cyst, ...and must undergo egress at four distinct phases during its complex life cycle, each time disrupting, in a highly regulated manner, the membranes or cyst wall that entrap the parasites. This Cell Science at a Glance article and accompanying poster summarises our current knowledge of the morphological features of egress across the
life cycle, the molecular mechanisms that govern the process, and how researchers are working to exploit this knowledge to develop much-needed new approaches to malaria control.
This paper provides a general analysis on the steady-state behavior and control principles of a recently proposed concept of "electric springs" that can be integrated into electrical appliances to ...become a new generation of smart loads. The discussion here is focused on how different real and/or reactive load powers can be canceled or altered using the electric springs. Mathematical derivations supporting the theoretical framework of the concept are detailed in the paper. Experimental results validate the theoretical discussions and solutions proposed. It is demonstrated that the electric spring is capable of providing different types of power/voltage compensations to the load and the source.
Nitrogen (N) generally limits plant growth and controls biosphere responses to climate change. We introduce a new mathematical model of plant N acquisition, called Fixation and Uptake of Nitrogen ...(FUN), based on active and passive soil N uptake, leaf N retranslocation, and biological N fixation. This model is unified under the theoretical framework of carbon (C) cost economics, or resource optimization. FUN specifies C allocated to N acquisition as well as remaining C for growth, or N-limitation to growth. We test the model with data from a wide range of sites (observed versus predicted N uptake r2 is 0.89, and RMSE is 0.003 kg N m-2·yr-1). Four model tests are performed: (1) fixers versus nonfixers under primary succession; (2) response to N fertilization; (3) response to CO2 fertilization; and (4) changes in vegetation C from potential soil N trajectories for five DGVMs (HYLAND, LPJ, ORCHIDEE, SDGVM, and TRIFFID) under four IPCC scenarios. Nonfixers surpass the productivity of fixers after approximately 150-180 years in this scenario. FUN replicates the N uptake response in the experimental N fertilization from a modeled N fertilization. However, FUN cannot replicate the N uptake response in the experimental CO2 fertilization from a modeled CO2 fertilization; nonetheless, the correct response is obtained when differences in root biomass are included. Finally, N-limitation decreases biomass by 50 Pg C on average globally for the DGVMs. We propose this model as being suitable for inclusion in the new generation of Earth system models that aim to describe the global N cycle.
Existing control schemes for single-phase ac-to-dc converters with active power-decoupling function typically involve a dedicated power-decoupling controller. Due to the highly coupled and nonlinear ...nature of the single-phase system, the design of the power-decoupling controller (typically based on the small-signal linear control techniques) is cumbersome, and the control structure is complicated. Additionally, with the existing power-decoupling control, it is hard to achieve satisfied dynamic responses and robust circuit operation. Following a recently proposed automatic-power-decoupling control scheme, this paper proposes a nonlinear control method that can achieve enhanced large-signal dynamic responses with strong disturbance rejection capability without the need for a dedicated power-decoupling controller. The proposed controller has a simple structure, of which the design is straightforward. The control method can be easily extended to other single-phase ac-to-dc systems with active power-decoupling function. Simulation and experimental results validate the feasibility of the proposed control method on a two-switch buck-boost PFC rectifier prototype.
Studying the determinants and the long-term consequences of fetal adipose accretion requires accurate assessment of neonatal body composition. In large epidemiological studies, in-depth body ...composition measurement methods are usually not feasible for cost and logistical reasons, and there is a need to identify anthropometric measures that adequately reflect neonatal adiposity.
In a multiethnic Asian mother-offspring cohort in Singapore, anthropometric measures (weight, length, abdominal circumference, skinfold thicknesses) were measured using standardized protocols in newborn infants, and anthropometric indices (weight/length, weight/length
(body mass index, BMI), weight/length
(ponderal index, PI)) derived. Neonatal total adiposity was measured using air displacement plethysmography (ADP) and abdominal adiposity using magnetic resonance imaging (MRI). Correlations of the anthropometric measures with ADP- and MRI-based adiposity were assessed using Pearson's correlation coefficients (r
), including in subsamples stratified by sex and ethnicity.
Study neonates (n=251) had a mean (s.d.) age of 10.2 (2.5) days. Correlations between ADP-based fat mass (ADP
) and anthropometric measures were moderate (r
range: 0.44-0.67), with the strongest being with weight/length, weight, BMI and sum of skinfolds (r
=0.67, 0.66, 0.62, 0.62, respectively, all P<0.01). All anthropometric measures except skinfold thicknesses correlated more strongly with ADP-based fat-free mass than ADP
, indicating that skinfold measures may have more discriminative power in terms of neonatal total body adiposity. For MRI-based measures, weight and weight/length consistently showed strong positive correlations (r
⩾0.7) with abdominal adipose tissue compartments. These correlations were consistent in boys and girls, across different ethnic groups, and when conventional determinants of neonatal adiposity were adjusted for potential confounding. Abdominal circumference was not strongly associated with ADP
or abdominal fat mass.
Simple anthropometric measures (weight and weight/length) correlated strongly with neonatal adiposity, with some evidence for greater discriminative power for skinfold measures. These simple measures could be of value in large epidemiological studies.
Intravenous tissue plasminogen activator (tPA) remains the cornerstone of recanalization therapy for acute ischemic stroke (AIS), albeit with varying degrees of response. The triglyceride-glucose ...(TyG) index is a novel marker of insulin resistance, but association with outcomes among AIS patients who have received tPA has not been well elucidated. We studied 698 patients with AIS who received tPA from 2006 to 2018 in a comprehensive stroke centre. TyG index was calculated using the formula: lnfasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2. TyG index was significantly lower in patients that survived at 90-days than those who died (8.61 Interquartile Range: 8.27-8.99 vs 8.76 interquartile range: 8.39-9.40, p = 0.007). In multivariate analysis, TyG index was significantly associated with 90-day mortality (OR: 2.12, 95% CI: 1.39-3.23, p = 0.001), poor functional outcome (OR: 1.41 95% CI: 1.05-1.90, p = 0.022), and negatively associated with early neurological improvement (ENI) (OR: 0.68, 95% CI: 0.52-0.89, p = 0.004). There was no association between TyG index and symptomatic intracranial hemorrhage. 'High TyG' (defined by TyG index ≥ 9.15) was associated with mortality, poor functional outcomes and no ENI. In conclusion, the TyG index, a measure of insulin resistance, was significantly associated with poorer clinical outcomes in AIS patients who received tPA.
In this multicentre study, we examined 60 cases of Type II enteropathy-associated T-cell lymphoma (EATL) from the Asia-Pacific region by histological review, immunohistochemistry and molecular ...techniques. Patients were mostly adult males (median age: 58 years, male:female 2.6:1), presenting with abdominal pain (60%), intestinal perforation (40%) and weight loss (28%). None had a history of coeliac disease and the median survival was only 7 months. Histologically, these tumours could be divided into (i) central tumour zone comprising a monotonous population of neoplastic lymphocytes, (ii) peripheral zone featuring stunted villi and morphologically atypical lymphocytes showing epitheliotropism, and (iii) distant mucosa with normal villous architecture and cytologically normal intra-epithelial lymphocytes (IELs). Characterized by extensive nuclear expression of Megakaryocyte-associated tyrosine kinase (MATK) (87%) and usually a CD8(+)CD56(+) (88%) cytotoxic phenotype, there was frequent aberrant expression of CD20 (24%). T-cell receptor (TCR) expression was silent or not evaluable in 40% but of the remainder, there was predominant expression of TCRαβ over TCRγδ (1.6:1). In keeping with the normal ratio of IEL subsets, CD8(+) cases showed predominant CD8αα homodimer expression (77%), regardless of TCR lineage. These tumours constitute a distinct entity from classical EATL, and the pathology may reflect tumour progression from IEL precursors, remnants of which are often seen in the distant mucosa.
This paper presents the first hardware implementation and control of an electric spring based on a back-to-back converter configuration. Because of its ability to provide both active and reactive ...power compensation, this back-to-back electric spring (ES-B2B) can substantially extend the operating range of the original version of the electric spring (ES-1) and provide enhanced voltage support and suppression functions. The hardware system and control of the ES-B2B have been successfully developed and tested. The experimental results have confirmed the effectiveness of the ES-B2B in supporting and suppressing the mains voltage. Particularly, the voltage suppression ability of the ES-B2B is superior over that of ES-1. The use of ES-B2B in a simulation study of a weak power grid has also been conducted. The ES-B2B has been found to be highly effective in mitigating voltage fluctuation caused by intermittent renewable power generation.
Snacks contribute toward a significant proportion of human total daily energy intake. This study investigated the effects of almonds, a satiating and nutrient-rich, common snack, on postprandial ...glycemia, appetite, short-term body weight and fasting blood parameters when consumed with meals or alone as a snack.
This was a 4-week randomized, parallel-arm study that entailed consuming almonds (43 g/day) with breakfast (BF) or lunch (LN), alone as a morning (MS) or afternoon (AS) snack or no almonds (CL). Participants (N=137) with increased risk for type 2 diabetes completed an oral glucose tolerance test (OGTT) and acute-feeding session at baseline, followed by almond consumption for 4 weeks before repeating the OGTT and acute-feeding trials. Anthropometric, biochemical and appetite responses were assessed.
Almonds lowered serum glucose responses postprandially. Effects were most prominent in the snack groups. Almonds, consumed as snacks, also reduced hunger and desire to eat during the acute-feeding session. After 4 weeks, anthropometric measurements and fasting blood biochemistries did not differ from the control group or across intervention groups. Without specific guidance, daily energy intake was reduced to compensate for energy from the provided almonds. Dietary monounsaturated fat and α-tocopherol intakes were significantly increased in all almond groups.
Almonds provide post-ingestive metabolic and appetitive benefits and did not increase the risk for weight gain. This suggests that almonds may be a healthful snack option.
Superconductivity in FeSe is greatly enhanced in films grown on SrTiO3 substrates, although the mechanism behind remains unclear. Recently, surface potassium (K) doping has also proven able to ...enhance the superconductivity of FeSe. Here, by using scanning tunneling microscopy, we compare the K doping dependence of the superconductivity in FeSe films grown on two substrates: SrTiO3 (001) and graphitized SiC (0001). For thick films (20 unit cells (UC)), the optimized superconducting (SC) gaps are of similar size (∼9 meV) regardless of the substrate. However, when the thickness is reduced to a few UC, the optimized SC gap is increased up to ∼15 meV for films on SrTiO3, whereas it remains unchanged for films on SiC. This clearly indicates that the FeSe/SrTiO3 interface can further enhance the superconductivity, beyond merely doping electrons. Intriguingly, we found that this interface enhancement decays exponentially as the thickness increases, with a decay length of 2.4 UC, which is much shorter than the length scale for relaxation of the lattice strain, pointing to interfacial electron–phonon coupling as the likely origin.
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