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1.
J Neurosci ; 44(21)2024 May 22.
Article in English | MEDLINE | ID: mdl-38569925

ABSTRACT

When we perceive a scene, our brain processes various types of visual information simultaneously, ranging from sensory features, such as line orientations and colors, to categorical features, such as objects and their arrangements. Whereas the role of sensory and categorical visual representations in predicting subsequent memory has been studied using isolated objects, their impact on memory for complex scenes remains largely unknown. To address this gap, we conducted an fMRI study in which female and male participants encoded pictures of familiar scenes (e.g., an airport picture) and later recalled them, while rating the vividness of their visual recall. Outside the scanner, participants had to distinguish each seen scene from three similar lures (e.g., three airport pictures). We modeled the sensory and categorical visual features of multiple scenes using both early and late layers of a deep convolutional neural network. Then, we applied representational similarity analysis to determine which brain regions represented stimuli in accordance with the sensory and categorical models. We found that categorical, but not sensory, representations predicted subsequent memory. In line with the previous result, only for the categorical model, the average recognition performance of each scene exhibited a positive correlation with the average visual dissimilarity between the item in question and its respective lures. These results strongly suggest that even in memory tests that ostensibly rely solely on visual cues (such as forced-choice visual recognition with similar distractors), memory decisions for scenes may be primarily influenced by categorical rather than sensory representations.


Subject(s)
Magnetic Resonance Imaging , Pattern Recognition, Visual , Recognition, Psychology , Humans , Male , Female , Adult , Young Adult , Recognition, Psychology/physiology , Pattern Recognition, Visual/physiology , Photic Stimulation/methods , Visual Perception/physiology , Brain/physiology , Brain/diagnostic imaging , Mental Recall/physiology , Brain Mapping
2.
Hippocampus ; 34(1): 2-6, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37904663

ABSTRACT

Episodic counterfactual thinking (ECT) consists of imagining alternative outcomes to past personal events. Previous research has shown that ECT shares common neural substrates with episodic future thinking (EFT): our ability to imagine possible future events. Both ECT and EFT have been shown to critically depend on the hippocampus, and past research has explored hippocampal engagement as a function of the perceived plausibility of an imagined future event. However, the extent to which the hippocampus is modulated by perceived plausibility during ECT is unknown. In this study, we combine two functional magnetic resonance imaging datasets to investigate whether perceived plausibility modulates hippocampal activity during ECT. Our results indicate that plausibility parametrically modulates hippocampal activity during ECT, and that such modulation is confined to the left anterior portion of the hippocampus. Moreover, our results indicate that this modulation is positive, such that increased activity in the left anterior hippocampus is associated with higher ratings of ECT plausibility. We suggest that neither effort nor difficulty alone can account for these results, and instead suggest possible alternatives to explain the role of the hippocampus during the construction of plausible and implausible ECT.


Subject(s)
Memory, Episodic , Thinking , Imagination , Hippocampus/diagnostic imaging , Temporal Lobe , Magnetic Resonance Imaging/methods
3.
Immunol Invest ; 53(4): 586-603, 2024 May.
Article in English | MEDLINE | ID: mdl-38700235

ABSTRACT

BACKGROUND: Acute myocardial infarction (AMI) is one of the principal causes of death in Mexico and worldwide. AMI triggers an acute inflammatory process that induces the activation of different populations of the innate immune system. Innate lymphoid cells (ILCs) are an innate immunity, highly pleiotropic population, which have been observed to participate in tissue repair and polarization of the adaptive immune response. OBJECTIVE: We aimed to analyze the levels of subsets of ILCs in patients with ST-segment elevation myocardial infarction (STEMI), immediately 3 and 6 months post-AMI, and analyze their correlation with clinical parameters. RESULTS: We evaluated 29 STEMI patients and 15 healthy controls and analyzed the different subsets of circulating ILCs, immediately 3 and 6 months post-AMI. We observed higher levels of circulating ILCs in STEMI patients compared to control subjects and a significant correlation between ILC levels and cardiac function. We also found increased production of the cytokines interleukin 5 (IL-5) and interleukin 17A (IL-17A), produced by ILC2 cells and by ILC3 cells, respectively, in the STEMI patients. CONCLUSION: This study shows new evidence of the role of ILCs in the pathophysiology of AMI and their possible involvement in the maintenance of cardiac function.


Subject(s)
Immunity, Innate , Lymphocytes , ST Elevation Myocardial Infarction , Humans , ST Elevation Myocardial Infarction/immunology , Male , Female , Middle Aged , Lymphocytes/immunology , Aged , Interleukin-17/metabolism , Interleukin-5 , Cytokines/metabolism , Case-Control Studies
4.
Cereb Cortex ; 33(19): 10234-10244, 2023 09 26.
Article in English | MEDLINE | ID: mdl-37526263

ABSTRACT

Visual mental imagery refers to our ability to experience visual images in the absence of sensory stimulation. Studies have shown that visual mental imagery can improve episodic memory. However, we have limited understanding of the neural mechanisms underlying this improvement. Using electroencephalography, we examined the neural processes associated with the retrieval of previously generated visual mental images, focusing on how the vividness at generation can modulate retrieval processes. Participants viewed word stimuli referring to common objects, forming a visual mental image of each word and rating the vividness of the mental image. This was followed by a surprise old/new recognition task. We compared retrieval performance for items rated as high- versus low-vividness at encoding. High-vividness items were retrieved with faster reaction times and higher confidence ratings in the memory judgment. While controlling for confidence, neural measures indicated that high-vividness items produced an earlier decrease in alpha-band activity at retrieval compared with low-vividness items, suggesting an earlier memory reinstatement. Even when low-vividness items were remembered with high confidence, they were not retrieved as quickly as high-vividness items. These results indicate that when highly vivid mental images are encoded, the speed of their retrieval occurs more rapidly, relative to low-vivid items.


Subject(s)
Memory, Episodic , Mental Recall , Humans , Mental Recall/physiology , Judgment , Imagery, Psychotherapy , Recognition, Psychology , Imagination/physiology
5.
Endocr Pract ; 30(1): 31-35, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37805101

ABSTRACT

OBJECTIVE: Thyroid palpation is a common clinical practice to detect thyroid abnormalities. However, its accuracy and potential for additional findings remain unclear. This study aimed to assess the diagnostic accuracy of physical exams in detecting thyroid nodules. METHODS: A retrospective observational study was conducted on a random sample of adult patients who underwent their first-time thyroid ultrasound between January 2015 and September 2017, following a documented thyroid physical exam. The study assessed the performance of thyroid palpation in detecting 1 or multiple thyroid nodules, as well as the proportion of additional findings on ultrasounds due to false positive thyroid palpation. RESULTS: We included 327 patients, mostly female (65.1%), white (84.1%), and treated in a primary care setting (54.4%) with a mean age of 50.8 years (SD 16.9). For solitary thyroid nodules, the physical exam had a sensitivity of 20.3%, specificity of 79.1%, an accuracy of 68.5%, negative predictive value of 81.8%, and positive predictive value of 17.6%. For detecting a multinodular goiter, physical exams demonstrated a sensitivity of 10.8%, specificity of 96.5%, accuracy of 55.4%, negative predictive value of 53.9, and positive predictive value of 73.9%. Among 154 cases with palpable nodules, 60% had additional nodules found in subsequent thyroid ultrasound. CONCLUSION: Thyroid physical exam has limited diagnostic performance and leads to additional findings when followed by a thyroid ultrasound. Future efforts should be directed at improving the accuracy of thyroid physical exams or re-evaluating its routine use.


Subject(s)
Goiter , Thyroid Neoplasms , Thyroid Nodule , Adult , Female , Humans , Male , Middle Aged , Palpation , Predictive Value of Tests , Retrospective Studies , Sensitivity and Specificity , Thyroid Neoplasms/diagnosis , Thyroid Nodule/diagnostic imaging , Ultrasonography , Aged
6.
Ecol Appl ; 33(3): e2798, 2023 04.
Article in English | MEDLINE | ID: mdl-36504412

ABSTRACT

Harnessing natural solutions to mitigate climate change requires an understanding of carbon fixation, flux, and sequestration across ocean habitats. Recent studies have suggested that exported seaweed particulate organic carbon is stored within soft-sediment systems. However, very little is known about how seaweed detritus disperses from coastlines, or where it may enter seabed carbon stores, where it could become the target of conservation efforts. Here, focusing on regionally dominant seaweed species, we surveyed environmental DNA (eDNA) from natural coastal sediments, and studied their connectivity to seaweed habitats using a particle tracking model parameterized to reproduce seaweed detritus dispersal behavior based on laboratory observations of seaweed fragment degradation and sinking. Experiments showed that seaweed detritus density changed over time, differently across species. This, in turn, modified distances traveled by released fragments until they reached the seabed for the first time, during model simulations. Dispersal pathways connected detritus from the shore to the open ocean but, importantly, also to coastal sediments, and this was reflected by field eDNA evidence. Dispersion pathways were also affected by hydrodynamic conditions, varying in space and time. Both the properties and timing of released detritus, individual to each macroalgal population, and short-term near-seabed and medium-term water-column transport pathways, are thus seemingly important in determining the connectivity between seaweed habitats and potential sedimentary sinks. Studies such as this one, supported by further field verification of sedimentary carbon sequestration rates and source partitioning, are still needed to help quantify the role of seaweed in the ocean carbon cycle. Such studies will provide vital evidence to inform on the potential need to develop blue carbon conservation mechanisms, beyond wetlands.


Subject(s)
Seaweed , Seaweed/metabolism , Climate Change , Ecosystem , Wetlands , Carbon/metabolism
7.
Psychophysiology ; 60(6): e14277, 2023 06.
Article in English | MEDLINE | ID: mdl-36841904

ABSTRACT

Autonomous sensory meridian response (ASMR) describes the experience of a pleasant body sensation accompanied by a feeling of well-being and relaxation in response to specific audiovisual stimuli, such as whispers and personal attention. Previous work suggests a relationship between this experience with the processing of affective and body states; however, no research has explored differences in interoception between people experiencing ASMR and those who do not. We hypothesized that the ASMR experience is based on interoception processing. To test this, we assessed group differences across different dimensions of interoception: Interoceptive sensibility (IS), measured using the multidimensional assessment of interoceptive awareness (MAIA); Interoceptive accuracy score (IAS), measured by calculating performance in a heartbeat counting task (HCT), and the electrophysiological index of interoception, the heartbeat evoked potential (HEP), which was calculated during the HCT and an ASMR tingle reporting task (ASMR-TRT). Our results showed that IS and IAS, dimensions requiring conscious awareness, showed no differences between groups. However, HEP amplitude was larger in the ASMR group in both tasks. We concluded that the ASMR experience is based on an unconscious interoceptive mechanism, reflected by HEP, where exteroceptive social-affective stimuli are integrated to represent a body state of positive affective feelings and relaxation, as has been described for affective touch. The relevance of this finding relies on that interoceptive function, body regulation, and emotional/affective experiences are fundamental for well-being, and the relationship between ASMR and interoception opens the way to future research exploring the causal relationship between them and their potential clinical applications.


Subject(s)
Evoked Potentials , Heart Rate , Interoception , Pleasure , Pleasure/physiology , Interoception/physiology , Humans , Male , Female , Young Adult , Adult
8.
Endocr Pract ; 29(12): 948-954, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37722595

ABSTRACT

OBJECTIVE: Excessive use of thyroid ultrasound (TUS) contributes to the overdiagnosis of thyroid nodules and thyroid cancer. In this study, we evaluated drivers of and clinical trajectories following TUS orders. METHODS: We conducted a retrospective review of 500 adult patients who underwent an initial TUS between 2015 and 2017 at Mayo Clinic in Rochester, MN. A framework was employed to classify the indication for TUS, and it was characterized as inappropriate when ordered without a guideline-based indication. Medical records were reviewed for up to 12 months following the TUS, and clinical outcomes were evaluated. RESULTS: The mean age mean age (SD) was 53.6 years (16.6), 63.8% female, and 86.6% white. TUS orders were triggered by incidental findings on unrelated imaging (31.6%), thyroid symptoms (20.4%), thyroid abnormalities on routine physical examination (17.2%), and thyroid dysfunction workup (11.8%). In females and males, the most common reason were incidental findings on imaging (female, 91/319, 28.5% and male, 67/181, 37.0%). In primary care practice, TUS orders were mostly triggered by symptoms (71/218, 32.5%), while thyroid dysfunction workup was the primary reason in endocrinology (28/100, 28.0%). We classified 11.2% (56/500) TUS orders as likely to have been ordered inappropriately based on current guidelines. Finally, 119 patients (119/500, 23.8%) had a thyroid biopsy with 11.8% had thyroid cancer (14/119. 11.8%). CONCLUSIONS: Incidental findings on imaging, symptoms, and routine physical exam findings in asymptomatic patients were the most prevalent drivers of TUS. Furthermore, 1 in 10 TUS were likely inappropriately ordered based on current practice guidelines.


Subject(s)
Thyroid Neoplasms , Thyroid Nodule , Adult , Humans , Male , Female , Middle Aged , Retrospective Studies , Thyroid Nodule/pathology , Thyroid Neoplasms/pathology , Biopsy , Ultrasonography
9.
J Integr Neurosci ; 22(2): 51, 2023 Mar 23.
Article in English | MEDLINE | ID: mdl-36992602

ABSTRACT

BACKGROUND: Over the last decade, there has been a steady increase in the number of children diagnosed with autism spectrum disorder (ASD) on a global scale, impacting all racial and cultural groups. This increase in the diagnostic rate has prompted investigation into a myriad of factors that may serve as early signs of ASD. One of these factors includes the biomechanics of gait, or the manner of walking. Although ASD is a spectrum, many autistic children experience differences in gross motor function, including gait. It has been documented that gait is also impacted by racial and cultural background. Given that ASD is equally prevalent across all cultural backgrounds, it is urgent that studies assessing gait in autistic children consider the impact of cultural factors on children's development of gait. The purpose of the present scoping review was to assess whether recent empirical research studies focusing on gait in autistic children have taken culture into account. METHODS: To do so, we conducted a scoping review following PRISMA guidelines using a keyword searching with the terms autism, OR autism spectrum disorder, OR ASD, OR autis, AND gait OR walking in the following databases: CINAHL, ERIC (EBSCO), Medline, ProQuest Nursing & Allied Health Source, PsychInfo, PubMed, and Scopus. Articles were considered for review if they met all six of the following inclusionary criteria: (1) included participants with a diagnosis of autism spectrum disorder (ASD), (2) directly measured gait or walking, (3) the article was a primary study, (4) the article was written in English, (5) participants included children up to age 18, and (6) the article was published between 2014 and 2022. RESULTS: A total of 43 articles met eligibility criteria but none of the articles took culture into account in the data analysis process. CONCLUSIONS: There is an urgent need for neuroscience research to consider cultural factors when assessing gait characteristics of autistic children. This would allow for more culturally responsive and equitable assessment and intervention planning for all autistic children.


Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Humans , Child , Adolescent , Autism Spectrum Disorder/complications , Autism Spectrum Disorder/diagnosis , Gait , Walking
10.
Sensors (Basel) ; 23(5)2023 Mar 06.
Article in English | MEDLINE | ID: mdl-36905072

ABSTRACT

Smart, and ultra-low energy consuming Internet of Things (IoTs), wireless sensor networks (WSN), and autonomous devices are being deployed to smart buildings and cities, which require continuous power supply, whereas battery usage has accompanying environmental problems, coupled with additional maintenance cost. We present Home Chimney Pinwheels (HCP) as the Smart Turbine Energy Harvester (STEH) for wind; and Cloud-based remote monitoring of its output data. The HCP commonly serves as an external cap to home chimney exhaust outlets; they have very low inertia to wind; and are available on the rooftops of some buildings. Here, an electromagnetic converter adapted from a brushless DC motor was mechanically fastened to the circular base of an 18-blade HCP. In simulated wind, and rooftop experiments, an output voltage of 0.3 V to 16 V was realised for a wind speed between 0.6 to 16 km/h. This is sufficient to operate low-power IoT devices deployed around a smart city. The harvester was connected to a power management unit and its output data was remotely monitored via the IoT analytic Cloud platform "ThingSpeak" by means of LoRa transceivers, serving as sensors; while also obtaining supply from the harvester. The HCP can be a battery-less "stand-alone" low-cost STEH, with no grid connection, and can be installed as attachments to IoT or wireless sensors nodes in smart buildings and cities.

11.
Behav Brain Sci ; 46: e370, 2023 11 14.
Article in English | MEDLINE | ID: mdl-37961786

ABSTRACT

Barzykowski and Moulin suggest that déjà vu and involuntary autobiographical memories recruit similar retrieval processes. Here, we invite the authors to clarify three issues: (1) What mechanism prevents déjà vu to happen more frequently? (2) What is the role of semantic cues in involuntary autobiographical retrieval? and (3) How déjà vu relates to non-believed memories?


Subject(s)
Cues , Memory, Episodic , Humans , Deja Vu , Semantics
12.
Microb Cell Fact ; 21(1): 181, 2022 Sep 07.
Article in English | MEDLINE | ID: mdl-36071433

ABSTRACT

BACKGROUND: Worldwide, an estimated 70.7 billion broilers were produced in 2020. With the reduction in use of prophylactic antibiotics as a result of consumer pressure and regulatory oversight alternative approaches, such as vaccination, are required to control bacterial infections. A potential way to produce a multivalent vaccine is via the generation of a glycoconjugate vaccine which consists of an antigenic protein covalently linked to an immunogenic carbohydrate. Protein-glycan coupling technology (PGCT) is an approach to generate glycoconjugates using enzymes that can couple proteins and glycan when produced in bacterial cells. Previous studies have used PGCT to generate a live-attenuated avian pathogenic Escherichia coli (APEC) strain capable of N-glycosylation of target proteins using a chromosomally integrated Campylobacter jejuni pgl locus. However, this proved ineffective against C. jejuni challenge. RESULTS: In this study we demonstrate the lack of surface exposure of glycosylated protein in APEC strain χ7122 carrying the pgl locus. Furthermore, we hypothesise that this may be due to the complex cell-surface architecture of E. coli. To this end, we removed the lipopolysaccharide O-antigen of APEC χ7122 pgl+ via deletion of the wecA gene and demonstrate increased surface exposure of glycosylated antigens (NetB and FlpA) in this strain. We hypothesise that increasing the surface expression of the glycosylated protein would increase the chance of host immune cells being exposed to the glycoconjugate, and therefore the generation of an efficacious immune response would be more likely. CONCLUSIONS: Our results demonstrate an increase in cell surface exposure and therefore accessibility of glycosylated antigens upon removal of lipopolysaccharide antigen from the APEC cell surface.


Subject(s)
Escherichia coli Infections , Escherichia coli , Animals , Chickens , Escherichia coli/genetics , Escherichia coli Infections/microbiology , Escherichia coli Infections/prevention & control , Escherichia coli Infections/veterinary , Glycoconjugates , Lipopolysaccharides
13.
Surg Endosc ; 36(7): 5160-5166, 2022 07.
Article in English | MEDLINE | ID: mdl-34845556

ABSTRACT

INTRODUCTION: Obesity is an expanding public health problem, resulting in more than half a billion adults worldwide. Intragastric balloon (IGB) placement is a weight loss alternative for obese patients with an inadequate weight loss response to diet and exercise. The aim of this study is to examine the efficacy and safety of the single-chamber fluid-filled IGB for weight loss and compare its results across different age groups. METHODS: We performed a database review of 239 consecutive patients from two outpatient GI clinics who underwent placement of an IGB. Our final analysis composed of 239 IGB placements in 232 patients (mean age, 44.5 ± 10.3 years; 67% female; baseline BMI 42.0 ± 9.0). Efficacy outcomes included the percentage of the total (%TWL) and excess weight loss (%EWL). Safety outcomes were measured as the number of patients who required early IGB removal (before 6 months). RESULTS: %TWL at 3 months was 10.1% and 14.4% at 6 months. Overall, 92%, 74%, and 47% of patients lost 5%, 10%, and 15% of total weight at 6 months, respectively. %EWL was 22.1% and 30.7% at 3 and 6 months post-IGB placement, respectively. The balloon was safely removed at six months after placement in most patients, whereas in 13.0% of cases early removal was performed at an average of 12.0 weeks after placement (range, 2 days-23 weeks). CONCLUSION: The use of a single-chamber fluid-filled IGB is successful in inducing a significant amount of weight loss in almost three-fourths of patients six months after its placement. This beneficial effect is seen across different BMI ranges and age groups at a similar level. IGBs should be considered an effective and safe alternative for obese patients who fail lifestyle interventions and conservative measures, fulfilling the unmet needs of many who are unwilling or unable to undergo bariatric surgery.


Subject(s)
Gastric Balloon , Obesity, Morbid , Adult , Body Mass Index , Female , Gastric Balloon/adverse effects , Humans , Male , Middle Aged , Obesity/surgery , Obesity, Morbid/surgery , Treatment Outcome , Weight Loss/physiology
14.
Sensors (Basel) ; 22(2)2022 Jan 11.
Article in English | MEDLINE | ID: mdl-35062507

ABSTRACT

Pollution in the form of litter in the natural environment is one of the great challenges of our times. Automated litter detection can help assess waste occurrences in the environment. Different machine learning solutions have been explored to develop litter detection tools, thereby supporting research, citizen science, and volunteer clean-up initiatives. However, to the best of our knowledge, no work has investigated the performance of state-of-the-art deep learning object detection approaches in the context of litter detection. In particular, no studies have focused on the assessment of those methods aiming their use in devices with low processing capabilities, e.g., mobile phones, typically employed in citizen science activities. In this paper, we fill this literature gap. We performed a comparative study involving state-of-the-art CNN architectures (e.g., Faster RCNN, Mask-RCNN, EfficientDet, RetinaNet and YOLO-v5), two litter image datasets and a smartphone. We also introduce a new dataset for litter detection, named PlastOPol, composed of 2418 images and 5300 annotations. The experimental results demonstrate that object detectors based on the YOLO family are promising for the construction of litter detection solutions, with superior performance in terms of detection accuracy, processing time, and memory footprint.


Subject(s)
Citizen Science , Deep Learning , Humans , Machine Learning , Smartphone
15.
Ann Surg ; 274(1): 50-56, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33630471

ABSTRACT

OBJECTIVE: The aim of this work is to formulate recommendations based on global expert consensus to guide the surgical community on the safe resumption of surgical and endoscopic activities. BACKGROUND: The COVID-19 pandemic has caused marked disruptions in the delivery of surgical care worldwide. A thoughtful, structured approach to resuming surgical services is necessary as the impact of COVID-19 becomes better controlled. The Coronavirus Global Surgical Collaborative sought to formulate, through rigorous scientific methodology, consensus-based recommendations in collaboration with a multidisciplinary group of international experts and policymakers. METHODS: Recommendations were developed following a Delphi process. Domain topics were formulated and subsequently subdivided into questions pertinent to different aspects of surgical care in the COVID-19 crisis. Forty-four experts from 15 countries across 4 continents drafted statements based on the specific questions. Anonymous Delphi voting on the statements was performed in 2 rounds, as well as in a telepresence meeting. RESULTS: One hundred statements were formulated across 10 domains. The statements addressed terminology, impact on procedural services, patient/staff safety, managing a backlog of surgeries, methods to restart and sustain surgical services, education, and research. Eighty-three of the statements were approved during the first round of Delphi voting, and 11 during the second round. A final telepresence meeting and discussion yielded acceptance of 5 other statements. CONCLUSIONS: The Delphi process resulted in 99 recommendations. These consensus statements provide expert guidance, based on scientific methodology, for the safe resumption of surgical activities during the COVID-19 pandemic.


Subject(s)
COVID-19/prevention & control , Elective Surgical Procedures , Endoscopy , Infection Control/organization & administration , COVID-19/epidemiology , COVID-19/transmission , Consensus , Delphi Technique , Humans , Internationality , Intersectoral Collaboration , Triage
16.
PLoS Pathog ; 15(12): e1008101, 2019 12.
Article in English | MEDLINE | ID: mdl-31877175

ABSTRACT

Active efflux due to tripartite RND efflux pumps is an important mechanism of clinically relevant antibiotic resistance in Gram-negative bacteria. These pumps are also essential for Gram-negative pathogens to cause infection and form biofilms. They consist of an inner membrane RND transporter; a periplasmic adaptor protein (PAP), and an outer membrane channel. The role of PAPs in assembly, and the identities of specific residues involved in PAP-RND binding, remain poorly understood. Using recent high-resolution structures, four 3D sites involved in PAP-RND binding within each PAP protomer were defined that correspond to nine discrete linear binding sequences or "binding boxes" within the PAP sequence. In the important human pathogen Salmonella enterica, these binding boxes are conserved within phylogenetically-related PAPs, such as AcrA and AcrE, while differing considerably between divergent PAPs such as MdsA and MdtA, despite overall conservation of the PAP structure. By analysing these binding sequences we created a predictive model of PAP-RND interaction, which suggested the determinants that may allow promiscuity between certain PAPs, but discrimination of others. We corroborated these predictions using direct phenotypic data, confirming that only AcrA and AcrE, but not MdtA or MsdA, can function with the major RND pump AcrB. Furthermore, we provide functional validation of the involvement of the binding boxes by disruptive site-directed mutagenesis. These results directly link sequence conservation within identified PAP binding sites with functional data providing mechanistic explanation for assembly of clinically relevant RND-pumps and explain how Salmonella and other pathogens maintain a degree of redundancy in efflux mediated resistance. Overall, our study provides a novel understanding of the molecular determinants driving the RND-PAP recognition by bridging the available structural information with experimental functional validation thus providing the scientific community with a predictive model of pump-contacts that could be exploited in the future for the development of targeted therapeutics and efflux pump inhibitors.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/drug effects , Membrane Transport Proteins/drug effects , Adaptor Proteins, Signal Transducing/metabolism , Animals , Bacterial Infections/drug therapy , Bacterial Proteins/drug effects , Bacterial Proteins/metabolism , Biological Transport/drug effects , Carrier Proteins/metabolism , Female , Membrane Transport Proteins/metabolism , Mice, Inbred BALB C , Periplasm/drug effects , Periplasm/metabolism , Salmonella typhimurium/drug effects , Salmonella typhimurium/metabolism
17.
Microb Cell Fact ; 20(1): 193, 2021 Oct 02.
Article in English | MEDLINE | ID: mdl-34600535

ABSTRACT

BACKGROUND: Poultry is the world's most popular animal-based food and global production has tripled in the past 20 years alone. Low-cost vaccines that can be combined to protect poultry against multiple infections are a current global imperative. Glycoconjugate vaccines, which consist of an immunogenic protein covalently coupled to glycan antigens of the targeted pathogen, have a proven track record in human vaccinology, but have yet to be used for livestock due to prohibitively high manufacturing costs. To overcome this, we use Protein Glycan Coupling Technology (PGCT), which enables the production of glycoconjugates in bacterial cells at considerably reduced costs, to generate a candidate glycan-based live vaccine intended to simultaneously protect against Campylobacter jejuni, avian pathogenic Escherichia coli (APEC) and Clostridium perfringens. Campylobacter is the most common cause of food poisoning, whereas colibacillosis and necrotic enteritis are widespread and devastating infectious diseases in poultry. RESULTS: We demonstrate the functional transfer of C. jejuni protein glycosylation (pgl) locus into the genome of APEC χ7122 serotype O78:H9. The integration caused mild attenuation of the χ7122 strain following oral inoculation of chickens without impairing its ability to colonise the respiratory tract. We exploit the χ7122 pgl integrant as bacterial vectors delivering a glycoprotein decorated with the C. jejuni heptasaccharide glycan antigen. To this end we engineered χ7122 pgl to express glycosylated NetB toxoid from C. perfringens and tested its ability to reduce caecal colonisation of chickens by C. jejuni and protect against intra-air sac challenge with the homologous APEC strain. CONCLUSIONS: We generated a candidate glycan-based multivalent live vaccine with the potential to induce protection against key avian and zoonotic pathogens (C. jejuni, APEC, C. perfringens). The live vaccine failed to significantly reduce Campylobacter colonisation under the conditions tested but was protective against homologous APEC challenge. Nevertheless, we present a strategy towards the production of low-cost "live-attenuated multivalent vaccine factories" with the ability to express glycoconjugates in poultry.


Subject(s)
Campylobacter Infections/prevention & control , Clostridium Infections/prevention & control , Escherichia coli Infections/prevention & control , Poultry Diseases/prevention & control , Vaccine Development/methods , Animals , Campylobacter jejuni/immunology , Chickens , Clostridium perfringens/immunology , Escherichia coli/immunology , Vaccines, Attenuated/immunology , Vaccines, Combined/immunology
18.
Sensors (Basel) ; 21(23)2021 Nov 24.
Article in English | MEDLINE | ID: mdl-34883831

ABSTRACT

This paper introduces a new solution to improve network performance by decreasing spectrum fragmentation, crosstalk interference, blocking of virtual networks, cost, and link load imbalance. These problems degrade the performance of Elastic Optical Networks with Space-Division Multiplexing. The proposed solution, called Cognitive control loop (CO-OP), is capable of identifying a set of problems and creating plans to mitigate these problems. The CO-OP comprises four functions that employ learning algorithms to identify problems and plan a series of actions to reduce or eliminate them. The results show that the CO-OP can effectively decrease up to 30% the blocking of requests and up to 50% the crosstalk occurrence compared to existing algorithms.


Subject(s)
Algorithms , Cognition
19.
Sensors (Basel) ; 21(9)2021 Apr 29.
Article in English | MEDLINE | ID: mdl-33946991

ABSTRACT

Panoramic dental radiography is one of the most used images of the different dental specialties. This radiography provides information about the anatomical structures of the teeth. The correct evaluation of these radiographs is associated with a good quality of the image obtained. In this study, 598 patients were consecutively selected to undergo dental panoramic radiography at the Department of Radiology of the Faculty of Dentistry, Universidad Nacional de Asunción. Contrast enhancement techniques are used to enhance the visual quality of panoramic dental radiographs. Specifically, this article presents a new algorithm for contrast, detail and edge enhancement of panoramic dental radiographs. The proposed algorithm is called Multi-Scale Top-Hat transform powered by Geodesic Reconstruction for panoramic dental radiography enhancement (MSTHGR). This algorithm is based on multi-scale mathematical morphology techniques. The proposal extracts multiple features of brightness and darkness, through the reconstruction of the marker (obtained by the Top-Hat transformation by reconstruction) starting from the mask (obtained by the classic Top-Hat transformation). The maximum characteristics of brightness and darkness are added to the dental panoramic radiography. In this way, the contrast, details and edges of the panoramic radiographs of teeth are improved. For the tests, MSTHGR was compared with the following algorithms: Geodesic Reconstruction Multiscale Morphology Contrast Enhancement (GRMMCE), Histogram Equalization (HE), Brightness Preserving Bi-Histogram Equalization (BBHE), Dual Sub-Image Histogram Equalization (DSIHE), Minimum Mean Brightness Error Bi-Histogram Equalization (MMBEBHE), Quadri-Histogram Equalization with Limited Contrast (QHELC), Contrast-Limited Adaptive Histogram Equalization (CLAHE) and Gamma Correction (GC). Experimentally, the numerical results show that the MSTHGR obtained the best results with respect to the Contrast Improvement Ratio (CIR), Entropy (E) and Spatial Frequency (SF) metrics. This indicates that the algorithm performs better local enhancements on panoramic radiographs, improving their details and edges.


Subject(s)
Radiographic Image Enhancement , Tooth , Algorithms , Humans , Image Enhancement , Radiography, Panoramic , Tooth/diagnostic imaging
20.
J Radiol Prot ; 41(2)2021 06 01.
Article in English | MEDLINE | ID: mdl-33588400

ABSTRACT

The Spanish Society for Radiological Protection (SEPR) is a scientific and technical organization that aims to bring together all radioprotection professionals from all the sectors of activity where ionizing and non-ionizing radiation is produced. The development of the SEPR's Strategic Plan every 5 years is the cornerstone of all the different activities that the Society carries out. This document establishes the SEPR goals and objectives for that period, as well as the activities planned to achieve them. It is a living and open document that draws on past experiences while looking to the future. The Strategic Plan 2019-2023, approved on June 2019, is the Third Strategic Plan of the SEPR. In its preparation, account has been taken of the experience obtained in the application of the two previous Strategic Plans, as well as of the new demands of the general public and of professionals in the area of radiological protection that have become apparent during the previous period. This paper describes the development of the current Strategic Plan, as well as the Plan itself, and briefly analyzes its implementation in the Conclusion.


Subject(s)
Radiation Protection , Forecasting , Organizational Objectives , Societies
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