Remote Monitoring of Fish in Small Streams: A Unified Approach Using Pit Tags

Accurate assessments of fish populations are often limited by re-observation or recapture events. Since the early 1990s, passive integrated transponders (PIT tags) have been used to understand the biology of many fish species. Until recently, PIT applications in small streams have been limited to physical recapture events. To maximize recapture probability, we constructed PIT antenna arrays in small streams to remotely detect individual fish. Experiences from two different laboratories (three case studies) allowed us to develop a unified approach to applying PIT technology for enhancing data assessments. Information on equipment, its installation, tag considerations, and array construction is provided. Theoretical and practical definitions are introduced to standardize metrics for assessing detection efficiency. We demonstrate how certain conditions (stream discharge, vibration, and ambient radio frequency noise) affect the detection efficiency and suggest that by monitoring these conditions, expectations of efficiency can be modified. We emphasize the importance of consistently estimating detection efficiency for fisheries applications

Midbody and primary cilium of neural progenitors release extracellular membrane particles enriched in the stem cell marker prominin-1

Expansion of the neocortex requires symmetric divisions of neuroepithelial cells, the primary progenitor cells of the developing mammalian central nervous system. Symmetrically dividing neuroepithelial cells are known to form a midbody at their apical (rather than lateral) surface. We show that apical midbodies of neuroepithelial cells concentrate prominin-1 (CD133), a somatic stem cell marker and defining constituent of a specific plasma membrane microdomain. Moreover, these apical midbodies are released, as a whole or in part, into the extracellular space, yielding the prominin-1–enriched membrane particles found in the neural tube fluid. The primary cilium of neuroepithelial cells also concentrates prominin-1 and appears to be a second source of the prominin-1–bearing extracellular membrane particles. Our data reveal novel origins of extracellular membrane traffic that enable neural stem and progenitor cells to avoid the asymmetric inheritance of the midbody observed for other cells and, by releasing a stem cell membrane microdomain, to potentially influence the balance of their proliferation versus differentiation

Fast continuous Fourier transforms

Referred to as FCFT (Fast Continuous Fourier Transforms), new algorithme are proposed to evaluate the (integral) Fourier transform of a continuons signal . These algorithms compute without truncation error the Fourier integral, over the sampling duration, of a continuous pseudo signal deduced from samples by polynomial interpolations of order 0 (step by step function) to 3 (cubic spline) . They are very fast because an FFT (Fast Fourier Transform) algorithm is used for the calculation of quadrature formulas . They seem to be especially applicable to the Fourier transform computation of non periodic and/or not band limited signais because the yielded spectrum is not periodic. In particular, with transient signais, calculations made beyond the half of the sampling frequency can be significant. The FCFT algorithme based upon polynomial interpolations of order 2 and 3 are particularly efficient .Ces algorithmes sont proposés pour évaluer la transformée de Fourier d'un signal continu. Ces algorithmes calculent sans erreur de troncature l'intégrale de Fourier sur la durée d'échantillonnage, d'un pseudo signal continu déduit des échantillons par interpolations polynomiales d'ordre 0 à 3. Pour les signaux transitoires, les calculs au-delà de la demi-fréquence d'échantillonnage peuvent être significatifs. Les algorithmes TFCR d'ordres 2 et 3 sont particulièrement efficace

Release of extracellular membrane vesicles from microvilli of epithelial cells is enhanced by depleting membrane cholesterol

AbstractWe previously reported on the occurrence of prominin-1-carrying membrane vesicles that are released into body fluids from microvilli of epithelial cells. This release has been implicated in cell differentiation. Here we have characterized these vesicles released from the differentiated Caco-2 cells. We find that in these vesicles, prominin-1 directly interacts with membrane cholesterol and is associated with a membrane microdomain. The cholesterol depletion using methyl-β-cyclodextrin resulted in a marked increase in their release, and a dramatic change in the microvillar ultrastructure from a tubular shape to a “pearling” state, with multiple membrane constrictions, suggesting a role of membrane cholesterol in vesicle release from microvilli

Sister Mary Joseph's Nodule at a University Teaching Hospital in Northwestern Tanzania: A Retrospective Review of 34 cases.

Sister Mary Joseph's nodule is a metastatic tumor deposit in the umbilicus and often represents advanced intra-abdominal malignancy with dismal prognosis. There is a paucity of published data on this subject in our setting. This study was conducted to describe the clinicopathological presentation and treatment outcome of this condition in our environment and highlight challenges associated with the care of these patients, and to proffer solutions for improved outcome. This was a retrospective study of histologically confirmed cases of Sister Mary Joseph's nodule seen at Bugando Medical Centre between March 2003 and February 2013. Data collected were analyzed using descriptive statistics. A total of 34 patients were enrolled in the study. Males outnumbered females by a ratio of 1.4:1. The vast majority of patients (70.6%) presented with large umbilical nodule > 2 cm in size. The stomach (41.1%) was the most common location of the primary tumor. Adenocarcinoma (88.2%) was the most frequent histopathological type. Most of the primary tumors (52.9%) were poorly differentiated. As the disease was advanced and metastatic in all patients, only palliative therapy was offered. Out of 34 patients, 11 patients died in the hospital giving a mortality rate of 32.4%. Patients were followed up for 24 months. At the end of the follow-up period, 14(60.9%) patients were lost to follow-up and the remaining 9 (39.1%) patients died. Patients survived for a median period of 28 weeks (range, 2 to 64 weeks). The nodule recurred in 6 (26.1%) patients after complete excision. Sister Mary Joseph's nodule of the umbilicus is not rare in our environment and often represents manifestation of a variety of advanced intra-abdominal malignancies. The majority of the patients present at a late stage and many with distant metastases. The patient's survival is very short leading to a poor outcome. Early detection of primary cancer at an early stage may improve the prognosis

Association of Tramadol Use With Risk of Hip Fracture.

Several professional organizations have recommended tramadol as one of the first-line or second-line therapies for patients with chronic noncancer pain and its prescription has been increasing rapidly worldwide; however, the safety profile of tramadol, such as risk of fracture, remains unclear. This study aimed to examine the association of tramadol with risk of hip fracture. Among individuals age 50 years or older without a history of hip fracture, cancer, or opioid use disorder in The Health Improvement Network (THIN) database in the United Kingdom general practice (2000-2017), five sequential propensity score-matched cohort studies were assembled, ie, participants who initiated tramadol or those who initiated one of the following medications: codeine (n = 146,956) (another commonly used weak opioid), naproxen (n = 115,109) or ibuprofen (n = 107,438) (commonly used nonselective nonsteroidal anti-inflammatory drugs [NSAIDs]), celecoxib (n = 43,130), or etoricoxib (n = 27,689) (cyclooxygenase-2 inhibitors). The outcome was incident hip fracture over 1 year. After propensity-score matching, the included participants had a mean age of 65.7 years and 56.9% were women. During the 1-year follow-up, 518 hip fracture (3.7/1000 person-years) occurred in the tramadol cohort and 401 (2.9/1000 person-years) occurred in the codeine cohort. Compared with codeine, hazard ratio (HR) of hip fracture for tramadol was 1.28 (95% confidence interval [CI] 1.13 to 1.46). Risk of hip fracture was also higher in the tramadol cohort than in the naproxen (2.9/1000 person-years for tramadol, 1.7/1000 person-years for naproxen; HR = 1.69, 95% CI 1.41 to 2.03), ibuprofen (3.4/1000 person-years for tramadol, 2.0/1000 person-years for ibuprofen; HR = 1.65, 95% CI 1.39 to 1.96), celecoxib (3.4/1000 person-years for tramadol, 1.8/1000 person-years for celecoxib; HR = 1.85, 95% CI 1.40 to 2.44), or etoricoxib (2.9/1000 person-years for tramadol, 1.5/1000 person-years for etoricoxib; HR = 1.96, 95% CI 1.34 to 2.87) cohort. In this population-based cohort study, the initiation of tramadol was associated with a higher risk of hip fracture than initiation of codeine and commonly used NSAIDs, suggesting a need to revisit several guidelines on tramadol use in clinical practice. © 2020 American Society for Bone and Mineral Research