Mosquito ageing modulates the development, virulence and transmission potential of pathogens.

Host age variation is a striking source of heterogeneity that can shape the evolution and transmission dynamic of pathogens. Compared with vertebrate systems, our understanding of the impact of host age on invertebrate-pathogen interactions remains limited. We examined the influence of mosquito age on key life-history traits driving human malaria transmission. Females of Anopheles coluzzii, a major malaria vector, belonging to three age classes (4-, 8- and 12-day-old), were experimentally infected with Plasmodium falciparum field isolates. Our findings revealed reduced competence in 12-day-old mosquitoes, characterized by lower oocyst/sporozoite rates and intensities compared with younger mosquitoes. Despite shorter median longevities in older age classes, infected 12-day-old mosquitoes exhibited improved survival, suggesting that the infection might act as a fountain of youth for older mosquitoes specifically. The timing of sporozoite appearance in the salivary glands remained consistent across mosquito age classes, with an extrinsic incubation period of approximately 13 days. Integrating these results into an epidemiological model revealed a lower vectorial capacity for older mosquitoes compared with younger ones, albeit still substantial owing to extended longevity in the presence of infection. Considering age heterogeneity provides valuable insights for ecological and epidemiological studies, informing targeted control strategies to mitigate pathogen transmission.

Fate of Quasiparticles at High Temperature in the Correlated Metal Sr_{2}RuO_{4}.

We study the temperature evolution of quasiparticles in the correlated metal Sr_{2}RuO_{4}. Our angle resolved photoemission data show that quasiparticles persist up to temperatures above 200 K, far beyond the Fermi liquid regime. Extracting the quasiparticle self-energy, we demonstrate that the quasiparticle residue Z increases with increasing temperature. Quasiparticles eventually disappear on approaching the bad metal state of Sr_{2}RuO_{4} not by losing weight but via excessive broadening from super-Planckian scattering. We further show that the Fermi surface of Sr_{2}RuO_{4}-defined as the loci where the spectral function peaks-deflates with increasing temperature. These findings are in semiquantitative agreement with dynamical mean field theory calculations.

Building on Capacity Established through US Centers for Disease Control and Prevention Global Health Programs to Respond to COVID-19, Cameroon.

The COVID-19 pandemic has highlighted the need for resilient health systems with the capacity to effectively detect and respond to disease outbreaks and ensure continuity of health service delivery. The pandemic has disproportionately affected resource-limited settings with inadequate health capacity, resulting in disruptions in health service delivery and worsened outcomes for key health indicators. As part of the US government's goal of ensuring health security, the US Centers for Disease Control and Prevention has used its scientific and technical expertise to build health capacity and address health threats globally. We describe how capacity developed through global health programs of the US Centers for Disease Control and Prevention in Cameroon was leveraged to respond to coronavirus disease and maintain health service delivery. The health system strengthening efforts in Cameroon can be applied in similar settings to ensure preparedness for future global public health threats and improve health outcomes.

[Long-duration home hospitalization: the impacts of socio-demographic and clinical factors and care pathways]. / Séjours longs en hospitalisation à domicile : impacts des facteurs sociodémographiques, cliniques et des parcours de soins.

INTRODUCTION: Although considerable literature exists concerning duration of stay in hospital settings, particularly for long-duration patients, we have little or no information about those hospitalized at home (HAH). We have studied the socio-demographic, clinical characteristics and care pathways of patients having undergone long-duration HAH. METHODS: One hundred and twenty-eight non-obstetric patients having undergone at least seven months of home hospitalization in 2018 and 2019 under the aegis of Assistance publique-Hôpitaux de Paris (AP-HP) were included and compared with 12381 shorter-duration patients. Data came from the French medicalized information system program (PMSI). A multivariate logistic regression model was developed and a descriptive analysis was carried out. RESULTS: Advanced age, residing in a nursing home, living alone, having several caregivers and being socially disadvantaged were associated with long-duration home hospitalization (HAH). These patients more often required complex dressings and palliative care, had more severe functional disability and were more frequently readmitted to hospital or died during the same period. In the multivariate model, advanced age, functional disability and transfer to HAH from conventional hospitalization were associated with increasingly lengthier home hospitalization. CONCLUSION: Long-duration home hospitalization was associated with a number of socio-demographic, clinical and care pathway-related factors. Further study of the advantages and drawbacks of HAH is called for.

Pneumothorax and Pregnancy: A Systematic Review of the Current Literature and Proposal of Treatment Recommendations.

INTRODUCTION: Spontaneous pneumothorax occurs rarely during pregnancy with less than 100 cases reported in the English literature. There is no strong evidence concerning the treatment of spontaneous pneumothorax during pregnancy and labor. The aim of this study is to systematically review all the reported cases and to suggest recommendations for its diagnosis and treatment. METHODS: A PubMed research was conducted. The following data were collected: maternal age, gestation age (weeks), presence of underlying lung pathology, initial management, definitive management, obstetric outcome, and the complications for the mother and the fetus. RESULTS: Eighty-seven cases were identified. The mean maternal age was 27 years (standard deviation [SD] ± 6). The mean gestational age was 25 weeks (SD ± 11.4). In 37.9% of cases, there was no underlying lung disease. In the majority of cases (67.4%), the initial treatment was the placement of a chest tube. In 48% of cases, the pneumothorax was resolved with conservative treatment. Surgical therapy was performed either antepartum or postpartum. In 58.6% of cases, there was a vaginal delivery, spontaneous or instrumental. In three cases (3.4%), there were fetal complications. CONCLUSION: The analysis of the current literature provides low evidence, since there are only case reports and small case series. It is likely that the frequency of this condition is underestimated. However, this analysis permits to draw some conclusions concerning the timing of pneumothorax treatment, the operative strategy, and the mode of delivery to decrease the risk for the mother and the fetus.

Nonlinear lattice dynamics as a basis for enhanced superconductivity in YBa2Cu3O6.5.

Terahertz-frequency optical pulses can resonantly drive selected vibrational modes in solids and deform their crystal structures. In complex oxides, this method has been used to melt electronic order, drive insulator-to-metal transitions and induce superconductivity. Strikingly, coherent interlayer transport strongly reminiscent of superconductivity can be transiently induced up to room temperature (300 kelvin) in YBa2Cu3O6+x (refs 9, 10). Here we report the crystal structure of this exotic non-equilibrium state, determined by femtosecond X-ray diffraction and ab initio density functional theory calculations. We find that nonlinear lattice excitation in normal-state YBa2Cu3O6+x at above the transition temperature of 52 kelvin causes a simultaneous increase and decrease in the Cu-O2 intra-bilayer and, respectively, inter-bilayer distances, accompanied by anisotropic changes in the in-plane O-Cu-O bond buckling. Density functional theory calculations indicate that these motions cause drastic changes in the electronic structure. Among these, the enhancement in the character of the in-plane electronic structure is likely to favour superconductivity.

A Common Kinetic Property of Mutations Linked to Episodic Ataxia Type 1 Studied in the Shaker Kv Channel.

(1) Background: Episodic ataxia type 1 is caused by mutations in the KCNA1 gene encoding for the voltage-gated potassium channel Kv1.1. There have been many mutations in Kv1.1 linked to episodic ataxia reported and typically investigated by themselves or in small groups. The aim of this article is to determine whether we can define a functional parameter common to all Kv1.1 mutants that have been linked to episodic ataxia. (2) Methods: We introduced the disease mutations linked to episodic ataxia in the drosophila analog of Kv1.1, the Shaker Kv channel, and expressed the channels in Xenopus oocytes. Using the cut-open oocyte technique, we characterized the gating and ionic currents. (3) Results: We found that the episodic ataxia mutations variably altered the different gating mechanisms described for Kv channels. The common characteristic was a conductance voltage relationship and inactivation shifted to less polarized potentials. (4) Conclusions: We suggest that a combination of a prolonged action potential and slowed and incomplete inactivation leads to development of ataxia when Kv channels cannot follow or adapt to high firing rates.

First and recurrent events after percutaneous coronary intervention: implications for survival analyses.

Objectives. Using composite endpoints and/or only first events in clinical research result in information loss and alternative statistical methods which incorporate recurrent event data exist. We compared information-loss under traditional analyses to alternative models. Design. We conducted a retrospective analysis of patients who underwent percutaneous coronary intervention (Jan2010-Dec2014) and constructed Cox models for a composite endpoint (readmission/death), a shared frailty model for recurrent events, and a joint frailty (JF) model to simultaneously account for recurrent and terminal events and evaluated the impact of heart failure (HF) on the outcome. Results. Among 4901 patients, 2047(41.8%) experienced a readmission or death within 1 year. Of those with recurrent events, 60% had ≥1 readmission and 6% had >4; a total of 121(2.5%) patients died during follow-up. The presence of HF conferred an adjusted Hazard ratio (HR) of 1.32 (95% CI: 1.18-1.47, p < .001) for the risk of composite endpoint (Cox model), 1.44 (95% CI: 1.36-1.52, p < .001) in the frailty model, and 1.34 (95% CI:1.22-1.46, p < .001) in the JF model. However, HF was not associated with death (HR 0.87, 95% CI: 0.52-1.48, p = .61) in the JF model. Conclusions. Using a composite endpoint and/or only the first event yields substantial loss of information, as many individuals endure >1 event. JF models reduce bias by simultaneously providing event-specific HRs for recurrent and terminal events.

Underwater acoustic energy fluctuations during strong internal wave activity using a three-dimensional parabolic equation model.

The three-dimensional Monterey-Miami parabolic equation model is used to simulate a nonlinear internal wave (NIW) crossing the sound field in a shallow water environment. The impetus for this research stems from acoustic measurements taken during the Shallow Water '06 (SW06) field experiment, where a NIW traversed the water column such that soliton wavecrests were nearly parallel to the source-receiver path. Horizontal refraction effects are important in this scenario. A sound speed profile adapted from experimental SW06 data is used to simulate the NIW, assuming variations along the wavecrests (e.g., curvature) are negligible. Broadband and modal energy metrics show acoustic fluctuations due to internal wave activity. Repeated model runs simulate the NIW crossing the parabolic equation (PE) field over space and time. Statistical analysis shows the PE data are best fit by a lognormal distribution but tends to an exponential distribution during certain scenarios. Small angle differences between the acoustic track and the propagating NIW cause substantial differences in energy distribution throughout the PE field. While refraction effects due to the leading edge of the NIW's arrival are important in all cases, the impacts of focusing and defocusing in the perfectly parallel case dominate the field fluctuations. In the non-parallel case, the strong fluctuations introduced by the passage of the NIW are of similar order to the refraction off the leading edge.

[Unilateral pigmentary retinopathy : about 2 cases]. / Le cas clinique du mois. Rétinopathie pigmentaire unilatérale.

We present the case of two patients in whom unilateral retinal involvement with pigmentary lesions on the fundus examination was observed. Apart from the unilateral nature of the lesions, a diagnosis of retinitis pigmentosa could have been made in view of the morphological and functional aspects of the retina. However, in these two clinical cases, an association between retinal lesions and Bartonella in one case, and pre-existing multiple sclerosis in the other case, has been proposed with a final diagnosis of unilateral pigmentary retinopathy. Nevertheless, a sufficiently long period of patient follow-up is necessary to rule out delayed onset in the unaffected eye, suggesting an asymmetrical bilateral retinitis pigmentosa.

Nous présentons le cas de deux patientes chez qui une atteinte rétinienne unilatérale comportant des lésions pigmentaires à l'examen du fond de l'œil a été observée. Malgré le caractère unilatéral des lésions, un diagnostic de rétinite pigmentaire d'origine génétique aurait pu être évoqué au vu des aspects morphologiques et fonctionnels de la rétine. Cependant, une origine infectieuse (infection à Bartonella) a pu être proposée pour un cas, alors que, pour l'autre cas, une atteinte inflammatoire secondaire à une sclérose en plaques a été retenue. Pour cette raison, le diagnostic final est celui d'une rétinopathie pigmentaire unilatérale. Néanmoins, un suivi à long terme est obligatoire de façon à écarter une apparition retardée des lésions dans l'œil indemne, ce qui pourrait indiquer la présence d'une rétinite pigmentaire bilatérale asymétrique.

Plant-Mediated Effects on Mosquito Capacity to Transmit Human Malaria.

The ecological context in which mosquitoes and malaria parasites interact has received little attention, compared to the genetic and molecular aspects of malaria transmission. Plant nectar and fruits are important for the nutritional ecology of malaria vectors, but how the natural diversity of plant-derived sugar sources affects mosquito competence for malaria parasites is unclear. To test this, we infected Anopheles coluzzi, an important African malaria vector, with sympatric field isolates of Plasmodium falciparum, using direct membrane feeding assays. Through a series of experiments, we then examined the effects of sugar meals from Thevetia neriifolia and Barleria lupilina cuttings that included flowers, and fruit from Lannea microcarpa and Mangifera indica on parasite and mosquito traits that are key for determining the intensity of malaria transmission. We found that the source of plant sugar meal differentially affected infection prevalence and intensity, the development duration of the parasites, as well as the survival and fecundity of the vector. These effects are likely the result of complex interactions between toxic secondary metabolites and the nutritional quality of the plant sugar source, as well as of host resource availability and parasite growth. Using an epidemiological model, we show that plant sugar source can be a significant driver of malaria transmission dynamics, with some plant species exhibiting either transmission-reducing or -enhancing activities.

Support for the Development of Technological Innovations: Promoting Responsible Social Uses.

How can technological development, economic development, and the claims from society be reconciled? How should responsible innovation be promoted? The "responsible social uses" approach proposed here was devised with these considerations in view. In this article, a support procedure for promoting responsible social uses (RSU) is set out and presented. First, the context in which this procedure emerged, which incorporates features of both the user-experience approach and that of ethical acceptability in technological development, is specified. Next, the characteristic features of the procedure are presented, that is, its purpose, fundamental orientation, and component parts as experimented by partners. Third, the RSU approach is compared with other support approaches and considered in term of how each approach assumes responsible innovation. Briefly, the RSU procedure is a way of addressing the issue of responsible innovation through an effective integration of social concerns.

Activation of ganglion cells and axon bundles using epiretinal electrical stimulation.

Epiretinal prostheses for treating blindness activate axon bundles, causing large, arc-shaped visual percepts that limit the quality of artificial vision. Improving the function of epiretinal prostheses therefore requires understanding and avoiding axon bundle activation. This study introduces a method to detect axon bundle activation on the basis of its electrical signature and uses the method to test whether epiretinal stimulation can directly elicit spikes in individual retinal ganglion cells without activating nearby axon bundles. Combined electrical stimulation and recording from isolated primate retina were performed using a custom multielectrode system (512 electrodes, 10-µm diameter, 60-µm pitch). Axon bundle signals were identified by their bidirectional propagation, speed, and increasing amplitude as a function of stimulation current. The threshold for bundle activation varied across electrodes and retinas, and was in the same range as the threshold for activating retinal ganglion cells near their somas. In the peripheral retina, 45% of electrodes that activated individual ganglion cells (17% of all electrodes) did so without activating bundles. This permitted selective activation of 21% of recorded ganglion cells (7% of expected ganglion cells) over the array. In one recording in the central retina, 75% of electrodes that activated individual ganglion cells (16% of all electrodes) did so without activating bundles. The ability to selectively activate a subset of retinal ganglion cells without axon bundles suggests a possible novel architecture for future epiretinal prostheses.NEW & NOTEWORTHY Large-scale multielectrode recording and stimulation were used to test how selectively retinal ganglion cells can be electrically activated without activating axon bundles. A novel method was developed to identify axon activation on the basis of its unique electrical signature and was used to find that a subset of ganglion cells can be activated at single-cell, single-spike resolution without producing bundle activity in peripheral and central retina. These findings have implications for the development of advanced retinal prostheses.

Theory of Laser-Controlled Competing Superconducting and Charge Orders.

We investigate the nonequilibrium dynamics of competing coexisting superconducting (SC) and charge-density wave (CDW) orders in an attractive Hubbard model. A time-periodic laser field A[over →](t) lifts the SC-CDW degeneracy, since the CDW couples linearly to the field (A[over →]), whereas SC couples in second order (A[over →]^{2}) due to gauge invariance. This leads to a striking resonance: When the photon energy is red detuned compared to the equilibrium single-particle energy gap, CDW is enhanced and SC is suppressed, while this behavior is reversed for blue detuning. Both orders oscillate with an emergent slow frequency, which is controlled by the small amplitude of a third induced order, namely η pairing, given by the commutator of the two primary orders. The induced η pairing is shown to control the enhancement and suppression of the dominant orders. Finally, we demonstrate that light-induced superconductivity is possible starting from a predominantly CDW initial state.

Does mosquito mass-rearing produce an inferior mosquito?

BACKGROUND: The success of the sterile insect technique depends, among other things, on continuous releases of sexually competitive sterile males within the target area. Several factors (including high rearing density and physical manipulation, such as larvae and pupae separation) can influence the quality of males produced in mass-rearing facilities. The different steps in mass production in the laboratory may modify the behaviour of mosquitoes, directly or through loss of natural characters as a result of adaptation to lab rearing, and lead to the competitiveness of sterile male being reduced. In the present study, the objective was to evaluate the effect of mass-rearing conditions on sterile male sexual competitiveness in semi-field cages compared to routine small scale laboratory rearing methods. METHODS: Anopheles arabiensis immature stages were reared both on a large scale using a rack and tray system developed by the FAO/IAEA (MRS), and on a small scale using standard laboratory rearing trays (SRS). Mosquito life history traits such as pupation rate, emergence rate, adult size as well as the effect of irradiation on adult longevity were evaluated. Moreover, 5-6 day old mosquitoes were released into field cages and left for two nights to mate and the mating competitiveness between sterile mass-reared males and fertile males reared on a small scale when competing for small scale reared virgin females was investigated. Resulting fertility in a treatment ratio of 1:1:1 (100 irradiated males: 100 non-irradiated males: 100 virgin females) was compared to control cages with 0:100:100 (non-irradiated control) and 100:0:100 (irradiated control). RESULTS: No significant differences in life history parameters were observed between rearing methods. The competitiveness index of mass reared males (0.58) was similar to males reared on a small scale (0.59). A residual fertility rate of 20% was observed in the irradiated control (100:0:100), measured as the percentage of eggs collected from the cages which developed to adulthood. No significant difference was observed (t = 0.2896, df = 4, P = 0.7865) between the rearing treatments (MRS and SRS) in the fertility rate, a measure of mating competitiveness. CONCLUSIONS: The results showed that the FAO/IAEA mass-rearing process did not affect mosquito life history parameters or the mating competitiveness of males.

Case report: preoperatively diagnosed perforated Meckel's diverticulum containing gastric and pancreatic-type mucosa.

BACKGROUND: Meckel's diverticulum is the most common congenital malformation of the gastrointestinal tract, and it represents a persistent remnant of the omphalomesenteric duct. Although it mostly remains silent, its infrequent occurrence is mirrored by the paucity of large series of data on it in the literature. Hemorrhage, obstruction and inflammation are most common complications of Meckel's diverticulum. Perforation of Meckel's diverticulum is considered very rare. CASE PRESENTATION: We present the case of a 17-year -old male, who presented to the emergency department with 1-day history of lower abdominal pain. CT of the abdomen suggested a perforated Meckel's diverticulum, which was confirmed later at the exploratory laparotomy. Perforation was due to progressive inflammation and presence of gastric and pancreatic tissue found on histopathology. CONCLUSION: Perforation of Meckel's diverticulum is rarely suspected. Complications of Meckel's diverticulum can be difficult to diagnose, and early recognition with timely operative intervention must occur in order to provide the best outcome for these patients. This is an interesting and unusual case of Meckel's diverticulum perforation that highlights the importance of considering Meckel's diverticulum as a differential diagnosis in every patient presenting with acute abdomen.

Cholera surveillance during the Haiti epidemic--the first 2 years.

BACKGROUND: In October 2010, nearly 10 months after a devastating earthquake, Haiti was stricken by epidemic cholera. Within days after detection, the Ministry of Public Health and Population established a National Cholera Surveillance System (NCSS). METHODS: The NCSS used a modified World Health Organization case definition for cholera that included acute watery diarrhea, with or without vomiting, in persons of all ages residing in an area in which at least one case of Vibrio cholerae O1 infection had been confirmed by culture. RESULTS: Within 29 days after the first report, cases of V. cholerae O1 (serotype Ogawa, biotype El Tor) were confirmed in all 10 administrative departments (similar to states or provinces) in Haiti. Through October 20, 2012, the public health ministry reported 604,634 cases of infection, 329,697 hospitalizations, and 7436 deaths from cholera and isolated V. cholerae O1 from 1675 of 2703 stool specimens tested (62.0%). The cumulative attack rate was 5.1% at the end of the first year and 6.1% at the end of the second year. The cumulative case fatality rate consistently trended downward, reaching 1.2% at the close of year 2, with departmental cumulative rates ranging from 0.6% to 4.6% (median, 1.4%). Within 3 months after the start of the epidemic, the rolling 14-day case fatality rate was 1.0% and remained at or below this level with few, brief exceptions. Overall, the cholera epidemic in Haiti accounted for 57% of all cholera cases and 53% of all cholera deaths reported to the World Health Organization in 2010 and 58% of all cholera cases and 37% of all cholera deaths in 2011. CONCLUSIONS: A review of NCSS data shows that during the first 2 years of the cholera epidemic in Haiti, the cumulative attack rate was 6.1%, with cases reported in all 10 departments. Within 3 months after the first case was reported, there was a downward trend in mortality, with a 14-day case fatality rate of 1.0% or less in most areas.

Large-scale Anopheles arabiensis egg quantification methods for mass-rearing operations.

BACKGROUND: The success of the sterile insect technique relies, among other things, on the continuous release of over flooding numbers of sexually competitive sterile males into the target area. To produce sufficiently large quantities of sterile males, rearing protocols need to be optimized including the development and validation of a standardized egg quantification method. METHODS: Batches of 1000 freshly laid eggs collected from standard rearing cages were counted, gently dried under laboratory conditions (27 ± 1 °C, 75 ± 5 % RH) and combined so that 1000-8000 eggs were weighed, to calculate the correlation between weight and number. The actual counted egg number and the egg number estimated by weighing were further compared for samples of 1000, 3000 and 4000 eggs collected from both standard and mass-rearing cages. The effect of drying, brushing and weighing on egg hatch rate was evaluated in three samples each of 1000 fresh and 1000 dried eggs, and in batches of 1000, 3000 and 4000 dried eggs. Pupal production and adult life history traits were assessed for dried eggs hatched and reared in mass-rearing trays. Expected egg numbers and actual observed mean egg numbers were compared after gentle drying, and after applying a rapid drying method exposure to wind speed of 1.8 m/s for 30 min. RESULTS: A significant positive relationship between the number of dried eggs and egg weight was observed and the equation 'Weight (mg) = (0.00399 × Number of counted eggs) + 0.536 was derived. The actual counted mean egg number and the egg number estimated by weighing were similar for samples from small rearing cages but significantly lower for samples of 3000 and 4000 egg samples collected from mass-rearing cages. No negative effect of the drying, brushing and weighing process on egg hatch rate was observed. No significant difference was observed in any life history trait between adults reared from dried or from fresh eggs up to twenty-one days post emergence. The mean number of eggs counted from a given replicate's weight was significantly higher for egg batches fast dried with a suction device compared to those dried with a gentle drying method (fast: 1075 ± 9, gentle: 1024 ± 7). CONCLUSION: An equation has been derived to allow accurate quantification of dried Anopheles arabiensis eggs based on weight, enabling more accurate quantification of eggs for consistent larval rearing density to be achieved. Eggs can be dried for weighing in a manner which does not impair the quality of resulting adults.