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1.
Zootaxa ; 5404(1): 167-188, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38480402

RESUMEN

Asia is the worlds largest continent and comprises most of the Holarctic biogeographic region. The genus Andrena is principally distributed through the Holarctic, but it remains understudied in Asia. The subgenus Cnemidandrena Hedicke, 1933 is distributed across Asia with some species reaching south to the Tibetan Plateau. However, some southern members display an unusual morphology, including A. (Cnemidandrena) kishidai chagyabensis Wu, 1982 (newly recorded for Bhutan, India, and Nepal) and A. (Cnemidandrena) granulitergorum Tadauchi & Xu, 2002 (newly recorded for Nepal). The male of A. granulitergorum is described for the first time, A. (Cnemidandrena) rufina Morawitz, 1876 is reported from Kyrgyzstan, Afghanistan, and Kashmir for the first time, and possible senior synonyms for Asian A. (Cnemidandrena) are suggested. To contribute to an improved understanding of localised Asian Andrena diversity, the following new species are described: A. (Cnemidandrena) textrix sp. nov. from China, A. (incertae sedis) liebigi sp. nov. and A. (Troandrena) monfaredi sp. nov. from Iran, and A. (incertae sedis) quercorum sp. nov. from Turkey. These results further confirm that additional taxonomic work is needed to harmonise Andrena species concepts across the different biogeographic regions of Asia.


Asunto(s)
Himenópteros , Abejas , Masculino , Animales
2.
BMC Ecol Evol ; 23(1): 67, 2023 11 20.
Artículo en Inglés | MEDLINE | ID: mdl-37986035

RESUMEN

BACKGROUND: Within the Hymenoptera, bees are notable for their relationship with flowering plants, being almost entirely dependent on plant pollen and nectar. Though functionally herbivorous, as a result of their role as pollinators, bees have received comparatively little attention as models for insect herbivory. Bees often display dietary specialization, but quantitative comparison against other herbivorous insects has not previously been conducted. RESULTS: In the most comprehensive analysis to date for 860 bee species, dietary specialization amounted to 50.1% of studied species collecting pollen from between 1 and 2 botanical families with a relatively long tail of dietary generalists, with 11.1% of species collecting from more than 10 botanical families. This distribution deviated from the truncated Pareto distribution of dietary breadth seen in other herbivorous insect lineages. However, this deviation was predominantly due to eusocial bee lineages, which show a range of dietary breadths that conformed to a normal distribution, while solitary bees show a typical truncated distribution not strongly different from other herbivorous insects. We hypothesize that the relatively low level of dietary specialization in bees as a whole reflects the relaxation of the constraints typically observed in herbivorous insects with a comparatively reduced importance of plant chemistry and comparatively increased importance of phenology and foraging efficiency. The long flight periods of eusocial bees that are necessary to allow overlapping generations both allows and necessitates the use of multiple flowering resources, whereas solitary bees with short flight periods have more limited access to varied resources within a constrained activity period. CONCLUSIONS: Collectively, solitary bees show slightly lower specialization compared to other herbivorous insects, possibly due to their balanced relationship with plants, rather than direct antagonism such as seen in the direct consumption of plant tissues. An additional factor may be the mediocre diversity of bees at low latitudes combined with low levels of dietary specialization, whereas these areas typically display a high rate of specialization by herbivorous insects in general. Though the most important factors structuring dietary specialization in bees appear to differ from many other herbivorous insects, solitary bees show a surprisingly similar overall pattern of dietary specialization.


Asunto(s)
Herbivoria , Insectos , Humanos , Abejas , Animales , Plantas , Polen , Néctar de las Plantas
3.
BMC Ecol Evol ; 22(1): 118, 2022 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-36261803

RESUMEN

BACKGROUND: The solely freshwater inhabiting Phylactolaemata is a sister taxon to all other bryozoans. Among phylactolaemates, Lophopodidae represents an early branching clade that is therefore crucial for ground pattern reconstruction. While more recent morphological data of most phylactolaemate families are present, data of lophopodids are scarce. The genus Asajirella especially, which was previously assigned to the family Pectinatellidae, lacks any detailed analysis with more recent morphological methods. RESULTS: This study provides the first morphological analyses of three lophopodid species using serial-sectioning histology and 3D reconstruction, but also immunocytochemical stainings and confocal laserscanning microscopy. There are several lophopodid-specific traits in the nervous system such as the large ganglion with extensive lumen and two prominent protrusions referred to as epistomial horns. The epistome in all lophopodids is rather small and dome-shaped. Contrary to previous reports, we can confirm that duplicature bands insert at the tentacle sheath rather than the diaphragmatic sphincter in all phylactolaemates. The morphology of the digestive tract of lophopodids is identical to other phylactolaemates and possesses exclusively circular muscles. CONCLUSIONS: Altogether, this study fills significant gaps in our knowledge on phylactolaemate neuromuscular systems and general morphology. It shows that the insertion of the duplicature bands at the tentacle sheath and the circular musculature of the digestive tract to be the ground pattern in phylactolaemates. In addition, we found apomorphic characters for lophopodids such as the dome-shaped epistome with its musculature and the voluminous ganglion with its epistomial horns, which aid in defining and delineating the family.


Asunto(s)
Briozoos , Humanos , Animales , Briozoos/anatomía & histología , Sistema Nervioso/anatomía & histología , Músculos/anatomía & histología , Agua Dulce , Tracto Gastrointestinal
4.
Biomed Phys Eng Express ; 8(6)2022 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-36049388

RESUMEN

Objective. To present and share an open-source system (phantom and software) for verifying the targeting accuracy of linac-based, single-isocenter, multi-target radiotherapy. This quality assurance test extends the traditional Winston-Lutz test, which considers a single target located at isocentre.Approach. Plans for a 3D-printed phantom are provided, which can be customized to accommodate various target (BB) positions. Given BB positions and gantry/collimator/couch combinations, the software generates multi-leaf collimator positions to facilitate multi-target Winston-Lutz (MTWL) plan creation. The software determines deviations between detected and expected BB positions on MV images resulting from MTWL plan delivery. BBs are located using a Hough circle detection algorithm, which is modified to favour the detection of circles: (1) having a reasonable size, (2) that are contained within the radiation field, and (3) having reasonable pixel intensities. Validation was performed in two ways: (1) using synthetic data with zero targeting errors and (2) by measuring real linac targeting errors and comparing against results obtained using a commercial system.Main results. Validation using the synthetic data yielded a mean (maximum) absolute discrepancy of 0.11 mm (0.21 mm), which is comparable to the synthetic phantom resolution (0.2 mm). The mean (maximum) absolute discrepancy compared to the commercial system is 0.13 mm (0.43 mm). These values are similar to results obtained with repeated deliveries of the same MTWL plan with the same phantom setup. Both validation tests yield reasonable results and are therefore considered successful. The MTWL test was performed independently by three physicists on two linacs to investigate repeatability, resulting in a mean (maximum) absolute discrepancy of 0.14 mm (0.51 mm) among the various attempts.Significance. Successful completion of this quality assurance test, using our customizable and open-source system, provides confidence that multi-target, single isocentre radiotherapy treatments can be delivered with sufficient geometric accuracy according to the chosen tolerance level.


Asunto(s)
Radiocirugia , Aceleradores de Partículas , Fantasmas de Imagen , Radiocirugia/métodos , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos
5.
Sci Justice ; 62(4): 471-475, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35931453

RESUMEN

Insects present on or near decomposing bodies are collected by forensic entomologists and used to estimate the post-mortem interval. Drugs metabolized by a person before death may affect the rate of development of insects feeding on the corpse. This study aimed to determine the effects of cocaine and heroin main metabolites on the development rate of the Calliphora vomitoria (Diptera: Calliphoridae) and their implications on minimum post-mortem interval determination. Groups of 250 eggs each were placed into four separate pots of 150 g of minced pork meat being either un-spiked, or spiked with benzoylecgonine, morphine, or a combination of both. Larval length (mm) and weight (mg) measurements were taken twice daily and the rate of development of the insects' life cycle was monitored until eclosion. Results show that cocaine-fed larvae developed less in length and weight than the control group. Heroin-fed larvae showed a more fluctuating pattern, being smaller and lighter than the control group for most of their larval cycle, but overtaking them in both parameters towards pupation. Combination-fed larvae seemed to favour the effects of cocaine. The three conditions also had a significant impact on the length of the insects' life cycle. Cocaine and drug combination treatments increased the length of the second and third instar stages, but led to the shortening of pupation and accelerated eclosion. Conversely, heroin treatment led to lengthier pupation. Interestingly, the effects of the drug combination seemed to mirror more precisely those of cocaine. These findings indicate that both cocaine and heroin, singularly and in combination, have sizable effects on blowflies' development rates, potentially biasing post-mortem interval estimations.


Asunto(s)
Cocaína , Dípteros , Animales , Calliphoridae , Entomología , Heroína/farmacología , Humanos , Larva
6.
Tech Coloproctol ; 26(3): 205-212, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35103901

RESUMEN

BACKGROUND: Surgical management of anal fistulas in Crohn's disease (CD) is associated with high failure rates, and treatment options are limited due to ongoing proctitis, multiple tracts, and concern for incontinence and non-healing wounds. The aim of this study was to investigate the healing rate of ligation of the inters-sphincteric fistula tract (LIFT) for anal fistulas in Crohn's disease and identify prognostic factors for healing. METHODS: This prospective analysis compared long-term healing rates of CD patients undergoing LIFT for anal fistulas. Consecutive patients with CD who underwent LIFT procedure at our institution, in the period from March 2012 to September 2019 were included. The main outcome was anal fistula healing rate. RESULTS: The study cohort of 46 patients (mean age of 34.2 ± 13.0 years, 18 (40%) males). After a mean follow-up time of 33 ± 28 months, fistula healing was seen in 30 (65%) patients. A total of 8 patients were noted to have inter-sphincteric recurrence and 8 patients had trans-sphincteric recurrence. Smoking at the time of surgery was significantly associated with LIFT failure (HR 3.18, 95% CI 1.18-8.61, p = 0.02). Other factors, such as age, sex, race, disease duration and location, type of fistula history of proctitis, preoperatively use of biologics or a seton, and previous repair attempts, did not appear to influence LIFT healing. Although not statistically significant, there was a trend toward increase in failure among patients with active proctitis at the time of surgery (HR 1.97, 95% CI 0.71-5.42, p = 0.19). CONCLUSION: Our increasing experience with LIFT for anal fistula in CD demonstrates a higher rate of healing (65%) than previously reported (48%). Smoking appears to negatively influence healing of LIFT in CD.


Asunto(s)
Enfermedad de Crohn , Fístula Rectal , Adulto , Canal Anal/cirugía , Enfermedad de Crohn/complicaciones , Enfermedad de Crohn/cirugía , Humanos , Ligadura/métodos , Masculino , Persona de Mediana Edad , Fístula Rectal/complicaciones , Fístula Rectal/cirugía , Recurrencia , Resultado del Tratamiento , Adulto Joven
7.
Phys Med ; 90: 53-65, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34562809

RESUMEN

Improvements in delivery of radiation dose to target tissues in radiotherapy have increased the need for better image quality and led to a higher frequency of imaging patients. Imaging for treatment planning extends to function and motion assessment and devices are incorporated into medical linear accelerators (linacs) so that regions of tissue can be imaged at time of treatment delivery to ensure dose distributions are delivered as accurately as possible. A survey of imaging in 97 radiotherapy centres in nine countries on six continents has been undertaken with an on-line questionnaire administered through the International Commission on Radiological Protection mentorship programme to provide a snapshot of imaging practices. Responses show that all centres use CT for planning treatments and many utilise additional information from magnetic resonance imaging and positron emission tomography scans. Most centres have kV cone beam CT attached to at least some linacs and use this for the majority of treatment fractions. The imaging options available declined with the human development index (HDI) of the country, and the frequency of imaging during treatment depended more on country than treatment site with countries having lower HDIs imaging less frequently. The country with the lowest HDI had few kV imaging facilities and relied on MV planar imaging intermittently during treatment. Imaging protocols supplied by vendors are used in most centres and under half adapt exposure conditions to individual patients. Recording of patient doses, a knowledge of which is important in optimisation of imaging protocols, was limited primarily to European countries.


Asunto(s)
Oncología por Radiación , Radioterapia Guiada por Imagen , Tomografía Computarizada de Haz Cónico , Humanos , Aceleradores de Partículas , Fantasmas de Imagen , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Encuestas y Cuestionarios
9.
Rev Sci Instrum ; 91(4): 043307, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32357713

RESUMEN

The standard 1X ISIS negative Penning surface plasma source has reliably produced an H- beam for ISIS operations for 35 years. In order to meet the 60 mA, 2 ms, and 50 Hz beam current and duty cycle required for the front end test stand (Letchford et al., in Proceedings of IPAC2015, Richmond, VA, USA, 2015), a 2X scaled source has been developed [Faircloth et al., AIP Conf. Proc. 2052, 050004 (2018)]. The 2X source has a plasma chamber twice the linear dimensions of the 1X source. This paper investigates the comparison between different emission areas (plasma electrode aperture dimensions) for both the 1X and 2X sources. Slit and circular extraction schemes are studied. A 3D Child-Langmuir relationship is observed where the space charge limited current density depends on the aspect ratio of the extraction aperture.

10.
J Appl Microbiol ; 127(6): 1768-1775, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31487414

RESUMEN

AIMS: Persister cells are stressed cells that have transient tolerance to antibiotics; these cells undergo no genetic change, but instead, their tolerance is due to reduced metabolism. Unfortunately, little is known about how persisters resuscitate, so we explored the waking of cells in the presence of the interkingdom signal indole. METHODS AND RESULTS: To generate a large population of persister cells, we induced the persister phenotype in the opportunistic pathogen Pseudomonas aeruginosa by pretreating cells with carbonyl cyanide m-chlorophenylhydrazone to reduce translation by depleting ATP levels, and found, via single cell observations, that proline is sufficient to wake the persister cells. P. aeruginosa is often present in the gastrointestinal tract, and indole from commensal bacteria such as Escherichia coli has been shown to inhibit P. aeruginosa quorum sensing and pathogenicity without influencing growth. Furthermore, indole is not toxic to P. aeruginosa persister cells. However, we find here that physiological concentrations of indole inhibit P. aeruginosa persister cell resuscitation with an efficiency of higher than 95%. Critically, when contacted with E. coli stationary-phase cultures, the indole produced by E. coli completely inhibits persister cell resuscitation of P. aeruginosa. CONCLUSIONS: Therefore, E. coli has devised a method to outcompete its competitors by preventing their resuscitation with indole. SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides insight into why indole is produced by commensal bacteria.


Asunto(s)
Escherichia coli/metabolismo , Indoles/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , Carbonil Cianuro m-Clorofenil Hidrazona/farmacología , Técnicas de Cocultivo , Indoles/metabolismo , Prolina/farmacología , Pseudomonas aeruginosa/fisiología , Percepción de Quorum/efectos de los fármacos
11.
J Appl Microbiol ; 127(6): 1859-1868, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31429177

RESUMEN

AIMS: Given the extreme toxicity of some of the toxins of toxin-antitoxin (TA) systems, we were curious how the cell silences toxins, if the antitoxin is inactivated or independent toxins are obtained via horizontal gene transfer. METHODS AND RESULTS: Growth curves of Escherichia coli K12 BW25113 harbouring plasmid pCA24N to produce RalR, MqsR, GhoT or Hha toxins, showed toxin inactivation after 3 h. Sequencing plasmids from these cultures revealed toxin inactivation occurred primarily due to consistent deletions in the promoter. The lack of mutation in the structural genes was corroborated by a bioinformatics analysis of 1000 E. coli genomes which showed both conservation and little variability in the four toxin genes. For those strains that lacked a mutation in the plasmid, single nucleotide polymorphism analysis was performed to identify that chromosomal mutations iraM and mhpR inactivate the toxins GhoT and MqsR/GhoT respectively. CONCLUSION: We find that the RalR (type I), MqsR (type II), GhoT (type V) and Hha (type VII) toxins are inactivated primarily by a mutation that inactivates the toxin promoter or via the chromosomal mutations iraM and mhpR. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates toxins of TA systems may be inactivated by mutations that primarily affect the toxin gene promoter instead of the toxin structural gene.


Asunto(s)
Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Mutación/genética , Regiones Promotoras Genéticas/genética , Sistemas Toxina-Antitoxina/genética , Cromosomas Bacterianos/genética , Escherichia coli/genética , Escherichia coli/crecimiento & desarrollo , Escherichia coli/fisiología , Proteínas de Escherichia coli/genética , Plásmidos/genética
12.
Proc Biol Sci ; 286(1905): 20190989, 2019 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-31213190

RESUMEN

Neonicotinoid insecticides have been linked to bee declines. However, tracking the primary exposure route for bees in the field has proven to be a major logistical challenge, impeding efforts to restore pollinator health in agricultural landscapes. We quantified neonicotinoid concentrations and botanical species composition in 357 pollen samples collected from 114 commercial honeybee colonies placed along a gradient of agricultural intensity between June and September. Neonicotinoid concentrations increased through the season, peaking at the end of August. As a result, concentrations in pollen were negatively associated with collection from woody and crop plants that flower early-mid season, and positively associated with collection from herbaceous plants that flower mid-late season. Higher clothianidin and thiamethoxam residues were correlated with samples containing a greater proportion of pollen collected from agricultural weeds. The percentage of agricultural land within 1500 m was positively correlated with thiamethoxam concentration; however, this spatial relationship was far weaker than the relationship with the proportion of pollen collected from herbaceous plants. These results indicate that both plant species identity and agricultural dominance are important in determining honeybee neonicotinoid exposure through the pollen diet, but that uncultivated plants associated with agriculture are the source of the greatest acute exposure.


Asunto(s)
Abejas/metabolismo , Exposición Dietética/estadística & datos numéricos , Monitoreo del Ambiente , Insecticidas/metabolismo , Neonicotinoides/metabolismo , Agricultura , Animales , Insecticidas/análisis , Neonicotinoides/análisis , Malezas , Polen/química , Polinización
13.
Ecology ; 100(6): e02697, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31012965

RESUMEN

Many species of bumble bee (Bombus) have declined in range and abundance across Europe, the Americas, and Asia, whereas other species have persisted and remain common and widespread. One explanation as to why some species have declined, based primarily on studies of the European bumble bee fauna, is that declining species have relatively narrow pollen-foraging niches and are less able to use alternative host plants in the absence of their preferred hosts. Though extensively explored in Europe, this hypothesis has not been investigated in North America, in part due to incomplete information on the foraging niche of many species. We selected 12 bumble bee species found in Michigan and quantified their pollen diets using museum specimens. We also extensively resurveyed the state to understand their contemporary status and distribution. Compared to a pre-2000 baseline, six species remain relatively common and widespread, whereas six species show range contractions of over 50%. There was a significant relationship between dietary breadth and distributional range change, with declined or declining species collecting around one-third fewer pollen types than stable species. Though there were significant compositional differences, we found no differences in the number of pollen types collected by species with differing tongue lengths. Overall, these results support the hypothesis that species with narrower dietary niches are at greater risk of decline. However, it is not clear if narrow dietary niches are a cause of declines, or if both are driven by an underlying factor such as proximity to the edge of climatic niches. Further research is needed to improve our understanding of dietary niche in bumble bees, and how it interacts with other factors to influence population trajectories of stable and at-risk species.


Asunto(s)
Dieta , Polen , Animales , Asia , Abejas , Europa (Continente) , Michigan , América del Norte
14.
J Geophys Res Atmos ; 124(23): 12824-12844, 2019 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-32025453

RESUMEN

Quantifying the efficacy of different climate forcings is important for understanding the real-world climate sensitivity. This study presents a systematic multimodel analysis of different climate driver efficacies using simulations from the Precipitation Driver and Response Model Intercomparison Project (PDRMIP). Efficacies calculated from instantaneous radiative forcing deviate considerably from unity across forcing agents and models. Effective radiative forcing (ERF) is a better predictor of global mean near-surface air temperature (GSAT) change. Efficacies are closest to one when ERF is computed using fixed sea surface temperature experiments and adjusted for land surface temperature changes using radiative kernels. Multimodel mean efficacies based on ERF are close to one for global perturbations of methane, sulfate, black carbon, and insolation, but there is notable intermodel spread. We do not find robust evidence that the geographic location of sulfate aerosol affects its efficacy. GSAT is found to respond more slowly to aerosol forcing than CO2 in the early stages of simulations. Despite these differences, we find that there is no evidence for an efficacy effect on historical GSAT trend estimates based on simulations with an impulse response model, nor on the resulting estimates of climate sensitivity derived from the historical period. However, the considerable intermodel spread in the computed efficacies means that we cannot rule out an efficacy-induced bias of ±0.4 K in equilibrium climate sensitivity to CO2 doubling when estimated using the historical GSAT trend.

15.
Ecol Appl ; 28(7): 1924-1934, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30184292

RESUMEN

Wild bee populations have undergone declines in recent years across much of the Western world, and these declines have the potential to limit yield in pollination-dependent crops. Highbush blueberry, Vaccinium corymbosum, and tart cherry, Prunus cerasus, are spring-blooming crops that rely on the movement of pollen by bees and other insects for pollination. Wild bee populations can be increased on farmland by providing floral resources, but whether the addition of these plants translates into increased pollinator density on crop flowers has not been documented in most cropping systems. To determine the importance of providing additional floral resources for wild bee pollinator communities, we selected blueberry fields and tart cherry orchards with and without herbaceous floral enhancements in western Michigan, USA. The bee communities visiting crop flowers, enhancements and control grassy field margins were sampled over a 5-yr period. In addition, the pollen diets of the most abundant wild bee crop pollinators were quantified across Michigan to better understand their foraging niches and to identify potentially important alternative host plants. The presence of floral enhancements did not increase the abundance of wild bees on either blueberry or cherry flowers during bloom. The bee community visiting blueberry was evenly composed of short-season bees that fly only during the spring and long-season bees that fly in both spring and summer. In contrast, the bee community visiting cherry was dominated by short-season spring bees. The majority of pollen collected by the wild bee communities visiting blueberry and cherry was from spring-flowering woody plants, with limited use of the herbaceous enhancements. Enhancements attracted greater abundance and species richness of bees compared to control areas, including twice as many floral specialists. Conserving summer-flying, grassland-associated bees is an appropriate goal for pollinator conservation programs. However, herbaceous enhancements may not provide adequate resources for the wild bees that pollinate spring-flowering crops. This study demonstrates that an examination of the pollen collected by wild bees across their flight periods can identify plant species to help them persist in intensively managed landscapes.


Asunto(s)
Abejas/fisiología , Biodiversidad , Dieta , Plantas , Polen , Animales , Productos Agrícolas , Conducta Alimentaria , Flores , Michigan , Estaciones del Año
16.
Clin Microbiol Rev ; 31(4)2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30068737

RESUMEN

Pathogens that infect the gastrointestinal and respiratory tracts are subjected to intense pressure due to the environmental conditions of the surroundings. This pressure has led to the development of mechanisms of bacterial tolerance or persistence which enable microorganisms to survive in these locations. In this review, we analyze the general stress response (RpoS mediated), reactive oxygen species (ROS) tolerance, energy metabolism, drug efflux pumps, SOS response, quorum sensing (QS) bacterial communication, (p)ppGpp signaling, and toxin-antitoxin (TA) systems of pathogens, such as Escherichia coli, Salmonella spp., Vibrio spp., Helicobacter spp., Campylobacter jejuni, Enterococcus spp., Shigella spp., Yersinia spp., and Clostridium difficile, all of which inhabit the gastrointestinal tract. The following respiratory tract pathogens are also considered: Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Burkholderia cenocepacia, and Mycobacterium tuberculosis Knowledge of the molecular mechanisms regulating the bacterial tolerance and persistence phenotypes is essential in the fight against multiresistant pathogens, as it will enable the identification of new targets for developing innovative anti-infective treatments.


Asunto(s)
Fenómenos Fisiológicos Bacterianos , Tracto Gastrointestinal/microbiología , Interacciones Huésped-Patógeno/fisiología , Sistema Respiratorio/microbiología , Interacciones Huésped-Patógeno/inmunología , Humanos , Percepción de Quorum , Estrés Fisiológico
17.
Epidemiol Infect ; 146(14): 1861-1869, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30047350

RESUMEN

We investigated risk factors for severe acute lower respiratory infections (ALRI) among hospitalised children 8 months were at greater risk from influenza-associated ICU admissions and long hospital stay. Children with ADV had increased LOS across all ages. In the first 2 years of life, the effects of different viruses on ALRI severity varies with age. Our findings help to identify specific ages that would most benefit from virus-specific interventions such as vaccines and antivirals.


Asunto(s)
Hospitalización/estadística & datos numéricos , Infecciones del Sistema Respiratorio/epidemiología , Enfermedad Aguda/epidemiología , Factores de Edad , Femenino , Humanos , Lactante , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Unidades de Cuidado Intensivo Pediátrico , Masculino , Nueva Zelanda/epidemiología , Infecciones del Sistema Respiratorio/virología , Factores de Riesgo , Fenómenos Fisiológicos de los Virus
18.
Rev Sci Instrum ; 89(5): 052101, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29864892

RESUMEN

A vessel for extraction and source plasma analyses is being used for Penning H- ion source development at the Rutherford Appleton Laboratory. A new set of optical elements including an einzel lens has been installed, which transports over 80 mA of H- beam successfully. Simultaneously, a 2X scaled Penning source has been developed to reduce cathode power density. The 2X source is now delivering a 65 mA H- ion beam at 10% duty factor, meeting its design criteria. The long-term viability of the einzel lens and 2X source is now being evaluated, so new diagnostic devices have been installed. A pair of electrostatic deflector plates is used to correct beam misalignment and perform fast chopping, with a voltage rise time of 24 ns. A suite of four quartz crystal microbalances has shown that the cesium flux in the vacuum vessel is only increased by a factor of two, despite the absence of a dedicated cold trap. Finally, an infrared camera has demonstrated good agreement with thermal simulations but has indicated unexpected heating due to beam loss on the downstream electrode. These types of diagnostics are suitable for monitoring all operational ion sources. In addition to experimental campaigns and new diagnostic tools, the high-performance VSim and COMSOL software packages are being used for plasma simulations of two novel ion thrusters for space propulsion applications. In parallel, a VSim framework has been established to include arbitrary temperature and cesium fields to allow the modeling of surface physics in H- ion sources.

19.
J Virol ; 92(6)2018 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-29298884

RESUMEN

The increased prevalence of drug-resistant, nosocomial Acinetobacter infections, particularly from pathogenic members of the Acinetobacter calcoaceticus-baumannii complex, necessitates the exploration of novel treatments such as phage therapy. In the present study, we characterized phage Petty, a novel podophage that infects multidrug-resistant Acinetobacter nosocomialis and Acinetobacter baumannii Genome analysis reveals that phage Petty is a 40,431-bp ϕKMV-like phage, with a coding density of 92.2% and a G+C content of 42.3%. Interestingly, the lysis cassette encodes a class I holin and a single-subunit endolysin, but it lacks canonical spanins to disrupt the outer membrane. Analysis of other ϕKMV-like genomes revealed that spaninless lysis cassettes are a feature of phages infecting Acinetobacter within this subfamily of bacteriophages. The observed halo surrounding Petty's large clear plaques indicated the presence of a phage-encoded depolymerase capable of degrading capsular exopolysaccharides (EPS). The product of gene 39, a putative tail fiber, was hypothesized to possess depolymerase activity based on weak homology to previously reported phage tail fibers. The 101.4-kDa protein gene product 39 (gp39) was cloned and expressed, and its activity against Acinetobacter EPS in solution was determined. The enzyme degraded purified EPS from its host strain A. nosocomialis AU0783, reducing its viscosity, and generated reducing ends in solution, indicative of hydrolase activity. Given that the accessibility to cells within a biofilm is enhanced by degradation of EPS, phages with depolymerases may have enhanced diagnostic and therapeutic potential against drug-resistant Acinetobacter strains.IMPORTANCE Bacteriophage therapy is being revisited as a treatment for difficult-to-treat infections. This is especially true for Acinetobacter infections, which are notorious for being resistant to antimicrobials. Thus, sufficient data need to be generated with regard to phages with therapeutic potential, if they are to be successfully employed clinically. In this report, we describe the isolation and characterization of phage Petty, a novel lytic podophage, and its depolymerase. To our knowledge, it is the first phage reported to be able to infect both A. baumannii and A. nosocomialis The lytic phage has potential as an alternative therapeutic agent, and the depolymerase could be used for modulating EPS both during infections and in biofilms on medical equipment, as well as for capsular typing. We also highlight the lack of predicted canonical spanins in the phage genome and confirm that, unlike the rounding of lambda lysogens lacking functional spanin genes, A. nosocomialis cells infected with phage Petty lyse by bursting. This suggests that phages like Petty employ a different mechanism to disrupt the outer membrane of Acinetobacter hosts during lysis.


Asunto(s)
Acinetobacter baumannii/virología , Bacteriófagos/enzimología , Bacteriófagos/genética , ARN Polimerasas Dirigidas por ADN/metabolismo , Genoma Viral , Proteínas Virales/metabolismo , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/aislamiento & purificación , ARN Polimerasas Dirigidas por ADN/genética , Genómica , Filogenia , Proteínas Virales/genética
20.
Pediatr Transplant ; 21(3)2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28145615

RESUMEN

Many young transplant recipients experience psychological distress and adjustment difficulties, yet there is little research investigating lung transplantation from the recipients' perspective. This qualitative study aimed to explore experiences of young people who underwent lung transplantation. Semi-structured interviews were conducted with six lung transplant recipients (aged 15-18). Interviews were analysed using IPA, a qualitative research approach examining how people make sense of their major life experiences. The analysis revealed three master themes: "Living with Dodgy Lungs" outlined how participants dealt with their experiences, managing through accepting or discussing their feelings with others, although talking was often difficult. "The Big Deal" reflected participants' experiences of the process, their expectations, and the contrast of their lives pre- and post-transplant. Inherent in their accounts was the profound meaning ascribed to transplantation, the emotional turmoil, and impact on their lives. "A Sense of Self" illustrated participants' developing identities within their social contexts and at times isolating experiences. The results highlight key areas where adolescent lung transplant recipients could be supported by clinicians, enabling the promotion of psychological well-being. Examples include supporting identity integration post-transplant, facilitating social inclusion, considering alternative means of support, and involving adolescents in healthcare decisions.


Asunto(s)
Adaptación Psicológica , Trasplante de Pulmón/psicología , Participación del Paciente , Satisfacción del Paciente , Adolescente , Fibrosis Quística/cirugía , Toma de Decisiones , Femenino , Humanos , Hipertensión Pulmonar/cirugía , Masculino , Investigación Cualitativa , Apoyo Social , Estrés Psicológico , Receptores de Trasplantes
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