500 research outputs found

    On the security of a new image encryption scheme based on chaotic map lattices

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    This paper reports a detailed cryptanalysis of a recently proposed encryption scheme based on the logistic map. Some problems are emphasized concerning the key space definition and the implementation of the cryptosystem using floating-point operations. It is also shown how it is possible to reduce considerably the key space through a ciphertext-only attack. Moreover, a timing attack allows the estimation of part of the key due to the existent relationship between this part of the key and the encryption/decryption time. As a result, the main features of the cryptosystem do not satisfy the demands of secure communications. Some hints are offered to improve the cryptosystem under study according to those requirements.Comment: 8 pages, 8 Figure

    Spanish & Haitian Creole Medical Terminology: Medical Translation Pocket Booklet

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    Language is an essential tool in the establishment of the doctor-patient relationship and is paramount to successful outcomes. According to the U.S census, 5.7 million Hispanic and 487,632 Haitians reside in Florida. This makes Spanish and Haitian Creole the second and third most predominantly spoken languages in the state. Hispanic physicians make up 6% of physicians in the U.S., and 15% of physicians in Florida. Black physicians make up 5.7% of physicians in the U.S., and 5.6% in Florida. An estimated 15% of Black physicians in the United States are Haitian, with a larger number practicing in states such as Florida. Despite the diversity of physicians in Florida, language barriers persist, causing significant adversity in healthcare. Interpreter services may not be available or the provider may not be adept in using them. To address these concerns, we have created a booklet with common phrases used in medical encounters, organized by subspecialty. We hope that this booklet can aid students and physicians in communicating with patients while waiting to be connected with a professional translator

    Dental Treatment under General Anesthesia in Healthy and Medically Compromised/Developmentally Disabled Children: A Comparative Study

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    Aim: To compare the type, number of procedures and working time of dental treatment provided under dental general anesthesia (DGA) in healthy and medically compromised/developmentally disabled children (MCDD children). Design: This cross-sectional prospective study involved 80 children divided into two groups of 40 children each. Group 1 consisted of healthy and Group 2 consisted of MCDD children. Results: Healthy children needed more working time than MCDD children, the means being 161±7.9 and 84±5.7 minutes, respectively (P= 0.0001). Operative dentistry and endodontic treatments showed a significant statistical difference (P= 0.0001). The means of procedures were 17±5.0 for healthy children and 11±4.8 for MCDD children (P= 0.0001). Conclusions: Healthy children needed more extensive dental treatment than MCDD children under DGA. The information from this sample of Mexican children could be used as reference for determining trends both within a facility as well as in comparing facilities in cross-population studies

    DiOLISTIC Labeling of Neurons from Rodent and Non-human Primate Brain Slices

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    DiOLISTIC staining uses the gene gun to introduce fluorescent dyes, such as DiI, into neurons of brain slices (Gan et al., 2009; O'Brien and Lummis, 2007; Gan et al., 2000). Here we provide a detailed description of each step required together with exemplary images of good and bad outcomes that will help when setting up the technique. In our experience, a few steps proved critical for the successful application of DiOLISTICS. These considerations include the quality of the DiI-coated bullets, the extent of fixative exposure, and the concentration of detergent used in the incubation solutions. Tips and solutions for common problems are provided

    Dopamine Regulation of Lateral Inhibition between Striatal Neurons Gates the Stimulant Actions of Cocaine

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    Striatal medium spiny neurons (MSNs) form inhibitory synapses on neighboring striatal neurons through axon collaterals. The functional relevance of this lateral inhibition and its regulation by dopamine remains elusive. We show that synchronized stimulation of collateral transmission from multiple indirect-pathway MSNs (iMSNs) potently inhibits action potentials in direct-pathway MSNs (dMSNs) in the nucleus accumbens. Dopamine D2 receptors (D2Rs) suppress lateral inhibition from iMSNs to disinhibit dMSNs, which are known to facilitate locomotion. Surprisingly, D2R inhibition of synaptic transmission was larger at axon collaterals from iMSNs than their projections to the ventral pallidum. Targeted deletion of D2Rs from iMSNs impaired cocaine's ability to suppress lateral inhibition and increase locomotion. These impairments were rescued by chemogenetic activation of Gi-signaling in iMSNs. These findings shed light on the functional significance of lateral inhibition between MSNs and offer a novel synaptic mechanism by which dopamine gates locomotion and cocaine exerts its canonical stimulant response.Fil: Dobbs, Lauren K.. National Institute on Alcohol Abuse and Alcoholism. Bethesda; Estados UnidosFil: Kaplan, Alanna R.. National Institute on Alcohol Abuse and Alcoholism. Bethesda; Estados UnidosFil: Lemos, Julia C.. National Institute on Alcohol Abuse and Alcoholism. Bethesda; Estados UnidosFil: Matsui, Aya. National Institute on Alcohol Abuse and Alcoholism. Bethesda; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Michigan State University; Estados UnidosFil: Alvarez, Veronica A.. National Institute on Alcohol Abuse and Alcoholism. Bethesda; Estados Unido

    Prefrontal cortex-driven dopamine signals in the striatum show unique spatial and pharmacological properties

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    Dopamine (DA) signals in the striatum are critical for a variety of vital processes, including motivation, motor learning, and reinforcement learning. Striatal DA signals can be evoked by direct activation of inputs from midbrain DA neurons (DANs) as well as cortical and thalamic inputs to the striatum. In this study, we show that in vivo optogenetic stimulation of prelimbic (PrL) and infralimbic (IL) cortical afferents to the striatum triggers an increase in extracellular DA concentration, which coincides with elevation of striatal acetylcholine (ACh) levels. This increase is blocked by a nicotinic ACh receptor (nAChR) antagonist. Using single or dual optogenetic stimulation in brain slices from male and female mice, we compared the properties of these PrL/IL-evoked DA signals with those evoked by stimulation from midbrain DAN axonal projections. PrL/IL-evoked DA signals are undistinguishable from DAN evoked DA signals in their amplitudes and electrochemical properties. However, PrL/IL-evoked DA signals are spatially restricted and preferentially recorded in the dorsomedial striatum. PrL/IL-evoked DA signals also differ in their pharmacological properties, requiring activation of glutamate and nicotinic ACh receptors. Thus, both in vivo and in vitro results indicate that cortical evoked DA signals rely on recruitment of cholinergic interneurons, which renders DA signals less able to summate during trains of stimulation and more sensitive to both cholinergic drugs and temperature. In conclusion, cortical and midbrain inputs to the striatum evoke DA signals with unique spatial and pharmacological properties that likely shape their functional roles and behavioral relevance.Fil: Adrover, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. National Institutes of Health; Estados UnidosFil: Shin, Jung Hoon. National Institutes of Health; Estados UnidosFil: Quiroz, Cesar. National Institutes of Health; Estados UnidosFil: Ferré, Sergi. National Institutes of Health; Estados UnidosFil: Lemos, Julia C.. National Institutes of Health; Estados UnidosFil: Alvarez, Veronica A.. National Institutes of Health; Estados Unido

    Management of extracranial arteriovenous malformations of the head and neck

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    The purpose of this study was to review the outcomes of the different therapies for extracranial head and neck arteriovenous malformations (AVMs). AVMs are high-flow congenital vascular anomalies. They are composed of a complex system of vessels directly connecting feeding arteries to draining veins forming a nidus. They may be potentially life-threatening due to progressive symptoms and infiltrative disease. Extracranial AVMs most commonly affect the head and neck area (47.4%) followed by the extremities (28.5%). AVMs are best characterized as being either focal or diffuse. Focal AVMs have good outcomes following adequate treatment. Diffuse lesions have multiple feeding vessel, which results in high rates of recurrence despite treatment. The management of AVMs includes conventional surgery and endovascular techniques. A combination of embolization and surgical resection has become the treatment of choice over the last years. The main goal of both forms of treatment being the complete blockage or resection of the nidus. Transcatheter embolization of vessels has evolved over the years and new embolic agents have emerged. The types of materials available for embolization are classified into mechanical devices, liquid agents and particulates. Efficacy, rate of recurrence and most common complications were evaluated. AVMs recurrence after embolization or resection is reported in up to 80% of cases. Incomplete resection and embolization can induce aggressive growth of the remaining nidus and the risk of progression is up to 50% within the first 5 years and recurrences can occur up to 10 years later. Although ethanol seems to be associated with the highest degree of cure and permanent occlusion, the overall complication rate reported was 48%. Other materials, such as cyanoacrylate, have obtained modest rates of complete remission, while the reported rates of complete regression of AVMs with Fibrin glue and Polyvinyl alcohol are above 50%. At present, there are no unified agreement on the ideal embolic agent. Therefore, a multidisciplinary approach is recommended to support decision making about the best therapeutic approach and to achieve optimal outcome. A long-term post-treatment follow-up is recommended to recognize early recurrence.Peer reviewe

    Malignant carotid body tumors: What we know, what we do, and what we need to achieve. A systematic review of the literature

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    : Malignant carotid body tumors (MCBT) are rare and diagnosed after detection of nodal or distant metastases. This systematic review (SR) focuses on MCBT initially approached by surgery. Preferred Reporting Items for SR and Meta-Analysis (MA) guided the articles search from 2000 to 2023 on PubMed, Scopus, and Web of Science. Among 3548 papers, 132 (337 patients) were considered for SR; of these, 20 (158 patients) for MA. Malignancy rate was 7.3%, succinate dehydrogenase (SDH) mutation 17%, age at diagnosis between 4th and 6th decades, with a higher prevalence of females. MCBTs were mostly Shamblin III, with nodal and distant metastasis in 79.7% and 44.7%, respectively. Malignancy should be suspected if CBT >4 cm, Shamblin III, painful or otherwise symptomatic, at the extremes of age, bilateral, with multifocal disease, and SDHx mutations. Levels II-III clearance should be performed to exclude nodal metastases and adjuvant treatments considered on a case-by-case basis

    Symbolic dynamics to enhance diagnostic ability of portable oximetry from the Phone Oximeter in the detection of paediatric sleep apnoea

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    Objective: This study is aimed at assessing symbolic dynamics as a reliable technique to characterize complex fluctuations of portable oximetry in the context of automated detection of childhood obstructive sleep apnoea-hypopnoea syndrome (OSAHS). Approach: Nocturnal oximetry signals from 142 children with suspected OSAHS were acquired using the Phone Oximeter: a portable device that integrates a pulse oximeter with a smartphone. An apnoea-hypopnoea index (AHI) ⩾ 5 events h−1 from simultaneous in-lab polysomnography was used to confirm moderate-to-severe childhood OSAHS. Symbolic dynamics was used to parameterise non-linear changes in the overnight oximetry profile. Conventional indices, anthropometric measures, and time-domain linear statistics were also considered. Forward stepwise logistic regression was used to obtain an optimum feature subset. Logistic regression (LR) was used to identify children with moderate-to-severe OSAHS. Main results: The histogram of 3-symbol words from symbolic dynamics showed significant differences (p < 0.01) between children with AHI < 5 events h−1 and moderate-to-severe patients (AHI ⩾ 5 events h−1). Words representing increasing oximetry values after apnoeic events (re-saturations) showed relevant diagnostic information. Regarding the performance of individual characterization approaches, the LR model composed of features from symbolic dynamics alone reached a maximum performance of 78.4% accuracy (65.2% sensitivity; 86.8% specificity) and 0.83 area under the ROC curve (AUC). The classification performance improved combining all features. The optimum model from feature selection achieved 83.3% accuracy (73.5% sensitivity; 89.5% specificity) and 0.89 AUC, significantly (p <0.01) outperforming the other models. Significance: Symbolic dynamics provides complementary information to conventional oximetry analysis enabling reliable detection of moderate-to-severe paediatric OSAHS from portable oximetry
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