449 research outputs found

    Periodic and Quasi-Periodic Compensation Strategies of Extreme Outages caused by Polarization Mode Dispersion and Amplifier Noise

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    Effect of birefringent disorder on the Bit Error Rate (BER) in an optical fiber telecommunication system subject to amplifier noise may lead to extreme outages, related to anomalously large values of BER. We analyze the Probability Distribution Function (PDF) of BER for various strategies of Polarization Mode Dispersion (PMD) compensation. A compensation method is proposed that is capable of more efficient extreme outages suppression, which leads to substantial improvement of the fiber system performance.Comment: 3 pages, 1 figure, Submitted to IEEE Photonics Letter

    400 Gbps Dual-Polarisation Non-Linear Frequency-Division Multiplexed Transmission with B-Modulation

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    We demonstrate, for the first time, a b-modulated dual-polarisation NFDM transmission in simulation, achieving a record net data rate of 400 Gbps (SE of 7.2 bit/s/Hz) over 960 km. The proposed scheme shows 1 dB Q-factor improvement over q c -modulation scheme

    The impact of young age on cancer-specific and non-cancer-related survival after surgery for colorectal cancer: 10-year follow-up

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    <b>Background</b>: It has been reported that although young patients present with more advanced disease, when adjusted for stage, cancer-specific survival is not different after surgery for colorectal cancer. However, few studies have examined non-cancer survival in young patients and 10-year survival has rarely been reported. Moreover, the largest study included patients of old age as a comparator. The aim of this study was to compare cancer-specific and non-cancer-related survival at 10 years in a young age cohort and a middle age cohort in patients undergoing surgery for colorectal cancer. <b>Methods</b>: Two thousand and seventy seven patients who underwent surgery for colorectal cancer between 1991 and 1994 in 11 hospitals in Scotland were included in the study. Ten-year cancer-specific and non-cancer-related survival and the hazard ratios (HR) were calculated according to age groups (<45/45–54/55–64/65–74 years). <b>Results</b>: On follow-up, 1066 patients died of their cancer and 369 died of non-cancer-related causes. At 10 years, overall survival was 32%, cancer-specific was 45%, and non-cancer-related survival was 72%. On multivariate analysis of all factors, sex (HR 0.77, 95% CI 0.68–0.88, P<0.001), mode of presentation (HR 1.64, 95% CI 1.44–1.87, P<0.01), Dukes' stage (HR 2.69, 95% CI 2.49–2.90, P<0.001), and specialisation (HR 1.24, 95% CI 1.04–1.44, P<0.01) were independently associated with cancer-specific survival. On multivariate analysis of all factors, age (HR 2.46, 2.04–2.97, P<0.001), sex (HR 0.56, 0.45–0.70, P<0.001), and deprivation (HR 1.16, 1.10–1.24, P<0.001) were independently associated with non-cancer-related survival. <b>Conclusion</b>: The results of this study confirm that young age does not have a negative impact on cancer-specific survival. Moreover, they show that, with 10-year follow-up, young age does not have a negative impact on non-cancer-related survival

    Vaccines against toxoplasma gondii : challenges and opportunities

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    Development of vaccines against Toxoplasma gondii infection in humans is of high priority, given the high burden of disease in some areas of the world like South America, and the lack of effective drugs with few adverse effects. Rodent models have been used in research on vaccines against T. gondii over the past decades. However, regardless of the vaccine construct, the vaccines have not been able to induce protective immunity when the organism is challenged with T. gondii, either directly or via a vector. Only a few live, attenuated T. gondii strains used for immunization have been able to confer protective immunity, which is measured by a lack of tissue cysts after challenge. Furthermore, challenge with low virulence strains, especially strains with genotype II, will probably be insufficient to provide protection against the more virulent T. gondii strains, such as those with genotypes I or II, or those genotypes from South America not belonging to genotype I, II or III. Future studies should use animal models besides rodents, and challenges should be performed with at least one genotype II T. gondii and one of the more virulent genotypes. Endpoints like maternal-foetal transmission and prevention of eye disease are important in addition to the traditional endpoint of survival or reduction in numbers of brain cysts after challenge

    A serological biomarker of type I collagen degradation is related to a more severe, high neutrophilic, obese asthma subtype

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    BACKGROUND: Asthma is a heterogeneous disease; therefore, biomarkers that can assist in the identification of subtypes and direct therapy are highly desirable. Asthma is a chronic inflammatory disease that leads to changes in the extracellular matrix (ECM) by matrix metalloproteinases (MMPs) degradation causing fragments of type I collagen that is released into circulation. OBJECTIVE: Here, we asked if MMP-generated type I collagen (C1M) was associated with subtypes of asthma. METHODS: C1M was serologically assessed at baseline in the adult participants of the All Age Asthma study (ALLIANCE) (n = 233), and in The Prospective Epidemiological Risk Factor study (PERF) (n = 283). In addition, C1M was assessed in mice sensitized to ovalbumin (OVA) and challenged with OVA aerosol. C1M was evaluated in mice with and without acute neutrophilic inflammation provoked by poly(cytidylic-inosinic) acid and mice treated with CP17, a peptide inhibiting neutrophil accumulation. RESULTS: Serum C1M was significantly increased in asthmatics compared to healthy controls (p = 0.0005). We found the increased C1M levels in asthmatics were related to blood neutrophil and body mass index (BMI) in the ALLIANCE cohort, which was validated in the PERF cohort. When patients were stratified into obese (BMI > 30) asthmatics with high neutrophil levels and uncontrolled asthma, this group had a significant increase in C1M compared to normal-weight (BMI < 25) asthmatics with low neutrophil levels and controlled asthma (p = 0.0277). C1M was significantly elevated in OVA mice with acute neutrophilic inflammation compared to controls (P = 0.0002) and decreased in mice treated with an inhibitor of neutrophil infiltration (p = 0.047). CONCLUSION & CLINICAL RELEVANCE: C1M holds the potential to identify a subtype of asthma that relates to severity, obesity, and high neutrophils. These data suggest that C1M is linked to a subtype of overall inflammation, not only derived from the lung. The link between C1M and neutrophils were further validated in in vivo model. TRIAL REGISTRATION: (ALLIANCE, NCT02419274). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40733-022-00084-6

    Familial adenomatous polyposis

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    Familial adenomatous polyposis (FAP) is characterized by the development of many tens to thousands of adenomas in the rectum and colon during the second decade of life. FAP has an incidence at birth of about 1/8,300, it manifests equally in both sexes, and accounts for less than 1% of colorectal cancer (CRC) cases. In the European Union, prevalence has been estimated at 1/11,300-37,600. Most patients are asymptomatic for years until the adenomas are large and numerous, and cause rectal bleeding or even anemia, or cancer develops. Generally, cancers start to develop a decade after the appearance of the polyps. Nonspecific symptoms may include constipation or diarrhea, abdominal pain, palpable abdominal masses and weight loss. FAP may present with some extraintestinal manifestations such as osteomas, dental abnormalities (unerupted teeth, congenital absence of one or more teeth, supernumerary teeth, dentigerous cysts and odontomas), congenital hypertrophy of the retinal pigment epithelium (CHRPE), desmoid tumors, and extracolonic cancers (thyroid, liver, bile ducts and central nervous system). A less aggressive variant of FAP, attenuated FAP (AFAP), is characterized by fewer colorectal adenomatous polyps (usually 10 to 100), later age of adenoma appearance and a lower cancer risk. Some lesions (skull and mandible osteomas, dental abnormalities, and fibromas on the scalp, shoulders, arms and back) are indicative of the Gardner variant of FAP. Classic FAP is inherited in an autosomal dominant manner and results from a germline mutation in the adenomatous polyposis (APC) gene. Most patients (~70%) have a family history of colorectal polyps and cancer. In a subset of individuals, a MUTYH mutation causes a recessively inherited polyposis condition, MUTYH-associated polyposis (MAP), which is characterized by a slightly increased risk of developing CRC and polyps/adenomas in both the upper and lower gastrointestinal tract. Diagnosis is based on a suggestive family history, clinical findings, and large bowel endoscopy or full colonoscopy. Whenever possible, the clinical diagnosis should be confirmed by genetic testing. When the APC mutation in the family has been identified, genetic testing of all first-degree relatives should be performed. Presymptomatic and prenatal (amniocentesis and chorionic villous sampling), and even preimplantation genetic testing is possible. Referral to a geneticist or genetic counselor is mandatory. Differential diagnoses include other disorders causing multiple polyps (such as Peutz-Jeghers syndrome, familial juvenile polyps or hyperplastic polyposis, hereditary mixed polyposis syndromes, and Lynch syndrome). Cancer prevention and maintaining a good quality of life are the main goals of management and regular and systematic follow-up and supportive care should be offered to all patients. By the late teens or early twenties, colorectal cancer prophylactic surgery is advocated. The recommended alternatives are total proctocolectomy and ileoanal pouch or ileorectal anastomosis for AFAP. Duodenal cancer and desmoids are the two main causes of mortality after total colectomy, they need to be identified early and treated. Upper endoscopy is necessary for surveillance to reduce the risk of ampullary and duodenal cancer. Patients with progressive tumors and unresectable disease may respond or stabilize with a combination of cytotoxic chemotherapy and surgery (when possible to perform). Adjunctive therapy with celecoxib has been approved by the US Food and Drug Administration and the European Medicines Agency in patients with FAP. Individuals with FAP carry a 100% risk of CRC; however, this risk is reduced significantly when patients enter a screening-treatment program

    ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries

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    This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors

    Óleos essenciais de espécies do gênero Aniba

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    Most Aniba (Lauraceae) species occur in Amazonia. They are represented by trees which contain essential oil in all of their organs. Oils from different organs of any species show little variation in composition. In contradistinction, such surprisingly drastic variation may be noted among different species, that they can be classified into groups. The linalool - group comprises A. duckei Kosterm. and A. rosaeodora Ducke. The benzyl benzoate - group comprises A. burchellii Kosterm., A. firmula (Nees et Mart.) Mez., A. fragrans Ducke, A. gardneri (Meissn.) Mez, A. guianensis Aubl., A. parviflora (Meissn.) Mez and A. permollis (Nees) Mez. The allylbenzene - group comprises A. canelilla (H.B.K.) Mez. A. hostmanniana (Nees) Mez and A. pseudocoto (Rusby) Kosterm. Detailed analysis revealed the presence in some of these oils of such rare plant products as l-nitro-2-phenylethane, phenylathyl benzoate, O-methylisoeugenol and 2, 4, 5-trimethoxyallylbenzene.A maior parte das espécies de Aniba (Lauraceae) se encontra na Amazônia. São representadas por árvores que contêm óleo essencial em todos os seus órgãos. Os óleos dos diferentes órgãos de qualquer espécie mostram somente uma pequena variação em sua composição. Em contrapartida, pode ser notada uma variação tão surpreendentemente drástica entre espécies diferentes que podem ser classificadas em grupos. O grupo linalol compreende A. duckei Kosterm. e A. rosaeodora Ducke. O grupo benzoato de benzilo compreende A. burchellii Kosterm., A. firmula (Nees & Mart.) Mez., A. fragrans Ducke, A. gardneri (Meissn.) Mez, A. guianensis Aubl., A. parviflora (Meissn.) Mez. e A. permollis (Nees) Mez. O grupo alilbenzeno compreende A. canelilla (H.B.K.) Mez., A. hostmanniana (Nees) Mez e A. pseudocoto (Rusby) Kosterm. A análise detalhada revelou a presença, em alguns destes óleos ,de produtos raros de plantas como l-nitro-2feniletano, benzoato de feniletilo O-metilisoeugenol e 2, 4, 5-trimetoxialilbenzeno
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