Melaena with Peutz-Jeghers syndrome: a case report

Introduction: Peutz-Jeghers syndrome (PJS) is a rare familial disorder characterised by mucocutaneous pigmentation, gastrointestinal and extragastrointestinal hamartomatous polyps and an increased risk of malignancy. Peutz-Jeghers polyps in the bowel may result in intussusception. This complication usually manifests with abdominal pain and signs of intestinal obstruction. Case Presentation: We report the case of a 24-year-old Caucasian male who presented with melaena. Pigmentation of the buccal mucosa was noted but he was pain-free and examination of the abdomen was unremarkable. Upper gastrointestinal endoscopy revealed multiple polyps. An urgent abdominal computed tomography (CT) scan revealed multiple small bowel intussusceptions. Laparotomy was undertaken on our patient, reducing the intussusceptions and removing the polyps by enterotomies. Bowel resection was not needed. Conclusion: Melaena in PJS needs to be urgently investigated through a CT scan even in the absence of abdominal pain and when clinical examination of the abdomen shows normal findings. Although rare, the underlying cause could be intussusception, which if missed could result in grave consequences

Cleaning of soft-solid soil layers on vertical and horizontal surfaces by stationary coherent impinging liquid jets

The cleaning action of stationary coherent liquid jets impinging (a) vertically downwards on horizontal plates, and (b) horizontally on vertical plates, was investigated using three soft-solid model soil layers: (i) PVA glue on glass and polymethylmethacrylate (Perspex) substrates; (ii) Xanthan gum on stainless steel; and (iii) petroleum jelly on glass. The liquid stream nozzle sizes, mass and volumetric flow rates and mean jet velocities investigated were: PVA, 2 mm, 17-50 g s^-1 (0.06-0.139 m^3 h^-1), 5.3-15.9 m s^-1; Xanthan gum, 0.39-3.3 mm, 2.1-148 g s^-1 (0.008-0.53 m^3 h^-1); 4.5-31.7 m s^-1; petroleum jelly, 2 mm, 7.8-50 g s^-1 (0.06-0.139 m^3 h^-1); 2.5-15.9 m s^-1. For all three soils, rapid initial removal of soil from the jet footprint was followed by the growth of a nearly circular, clean region centred at the point of jet impingement. The rate of removal of soil decreased sharply when the cleaning front reached the hydraulic or film jump. The data for the radial growth removal stage were compared with a mathematical model describing removal of the adhesive soil layer, where the force on the cleaning front was evaluated using the result reported by Wilson et al. (2011): their theory gave the momentum of the liquid film; this momentum was balanced against the soil strength, giving a simple relation between the cleaned radius and time. All three soils showed reasonable agreement with the model, across the range of flow rates and temperatures studied. The kinetic constant in the model was sensitive to soil layer thickness and the nature of the soil. Cleaning tests on the petroleum jelly soils at different temperatures, and separate rheological measurements, showed that the kinetic time constant for coating removal was proportional to the (critical shear stress)^-1.8. There was good agreement between results obtained with vertical and horizontal plates for the PVA and Xanthan gum soil layers. The petroleum jelly results differed, which is partly attributed to differences in preparing the layers of this rheologically complex material.This is the author's accepted manuscript and is under embargo until 3/2/16. The final published version can be found in Chemical Engineering Science here: http://www.sciencedirect.com/science/article/pii/S000925091400044X

Insulin autoantibodies as determined by competitive radiobinding assay are positively correlated with impaired beta-cell function — The Ulm-Frankfurt population study

Out of a random population of 4208 non-diabetic pupils without a family history of Type I diabetes 44 (1.05%) individuals had islet cell antibody (ICA) levels greater or equal to 5 Juvenile Diabetes Foundation (JDF) units. 39 of these ICA-positives could be repeatedly tested for circulating insulin autoantibodies (CIAA) using a competitive radiobinding assay. The results were compared with the insulin responses in the intravenous glucose tolerance tests (IVGTT) and with HLA types. Six pupils were positive for CIAA. All of them had complement-fixing ICA, and 5 of them were HLA-DR4 positive. Three of the 6 showed a first-phase insulin response below the first percentile of normal controls. Our data indicate that in population-based studies CIAA can be considered as a high risk marker for impaired beta-cell function in non-diabetic ICA-positive individuals

Shoulder pain due to cervical radiculopathy: an underestimated long-term complication of herpes zoster virus reactivation?

Purpose To evaluate if herpes zoster virus (HZV) reactivation may be considered in the aetiology of cervical radiculopathy. Methods The study group was composed of 110 patients (52 M-58F;mean age ± SD:46.5 ± 6.12; range:40-73) with a clinical diagnosis of cervical radiculopathy. Patients with signs of chronic damage on neurophysiological studies were submitted to an X-ray and to an MRI of the cervical spine in order to clarify the cause of the cervical radiculopathy and were investigated for a possible reactivation of HZV; HZV reactivation was considered as “recent” or “antique” if it occurs within or after 24 months from the onset of symptoms, respectively. Data were submitted to statistics. Results Thirty-eight patients (34,5%,16 M-22F) had a history of HZV reactivation: four (2 M-2F) were “recent” and 34 (14 M-20F) were “antique”. In 68 of 110 participants (61,8%,30 M-38F), pathological signs on X-ray and/or MRI of the cervical spine appeared; in the remaining 42 (38,2%,22 M-20F) X-ray and MRI resulted as negative. Among patients with HZV reactivation, seven (18,4%) had a “positive” X-ray-MRI while in 31 (81,6%) the instrumental exams were considered as negative. The prevalence of “antique” HZV reactivations was statistically greater in the group of patients with no pathological signs on X-ray/MRI of the cervical spine with respect to the group with a pathological instrumental exam (p < 0.01). Conclusions It may be useful to investigate the presence of a positive history of HZV reactivation and to consider it as a long-term complication of a cervical root inflammation especially in patients in which X-ray and MRI of the cervical spine did not show pathological findings

Validity of the Polar V800 heart rate monitor to measure RR intervals at rest

Purpose To assess the validity of RR intervals and short-term heart rate variability (HRV) data obtained from the Polar V800 heart rate monitor, in comparison to an electrocardiograph (ECG). Method Twenty participants completed an active orthostatic test using the V800 and ECG. An improved method for the identification and correction of RR intervals was employed prior to HRV analysis. Agreement of the data was assessed using intra-class correlation coefficients (ICC), Bland–Altman limits of agreement (LoA), and effect size (ES). Results A small number of errors were detected between ECG and Polar RR signal, with a combined error rate of 0.086 %. The RR intervals from ECG to V800 were significantly different, but with small ES for both supine corrected and standing corrected data (ES 0.999 for both supine and standing corrected intervals. When analysed with the same HRV software no significant differences were observed in any HRV parameters, for either supine or standing; the data displayed small bias and tight LoA, strong ICC (>0.99) and small ES (≤0.029). Conclusions The V800 improves over previous Polar models, with narrower LoA, stronger ICC and smaller ES for both the RR intervals and HRV parameters. The findings support the validity of the Polar V800 and its ability to produce RR interval recordings consistent with an ECG. In addition, HRV parameters derived from these recordings are also highly comparable

Computing the common zeros of two bivariate functions via Bézout resultants

The common zeros of two bivariate functions can be computed by finding the common zeros of their polynomial interpolants expressed in a tensor Chebyshev basis. From here we develop a bivariate rootfinding algorithm based on the hidden variable resultant method and Bézout matrices with polynomial entries. Using techniques including domain subdivision, Bézoutian regularization, and local refinement we are able to reliably and accurately compute the simple common zeros of two smooth functions with polynomial interpolants of very high degree (≥ 1000). We analyze the resultant method and its conditioning by noting that the Bézout matrices are matrix polynomials. Two implementations are available: one on the Matlab Central File Exchange and another in the roots command in Chebfun2 that is adapted to suit Chebfun’s methodology

Getting into hot water:sick guppies frequent warmer thermal conditions

Ectotherms depend on the environmental temperature for thermoregulation and exploit thermal regimes that optimise physiological functioning. They may also frequent warmer conditions to up-regulate their immune response against parasite infection and/or impede parasite development. This adaptive response, known as ‘behavioural fever’, has been documented in various taxa including insects, reptiles and fish, but only in response to endoparasite infections. Here, a choice chamber experiment was used to investigate the thermal preferences of a tropical freshwater fish, the Trinidadian guppy (Poecilia reticulata), when infected with a common helminth ectoparasite Gyrodactylus turnbulli, in female-only and mixed-sex shoals. The temperature tolerance of G. turnbulli was also investigated by monitoring parasite population trajectories on guppies maintained at a continuous 18, 24 or 32 °C. Regardless of shoal composition, infected fish frequented the 32 °C choice chamber more often than when uninfected, significantly increasing their mean temperature preference. Parasites maintained continuously at 32 °C decreased to extinction within 3 days, whereas mean parasite abundance increased on hosts incubated at 18 and 24 °C. We show for the first time that gyrodactylid-infected fish have a preference for warmer waters and speculate that sick fish exploit the upper thermal tolerances of their parasites to self medicate

C4 photosynthesis boosts growth by altering physiology, allocation and size.

C4 photosynthesis is a complex set of leaf anatomical and biochemical adaptations that have evolved more than 60 times to boost carbon uptake compared with the ancestral C3 photosynthetic type(1-3). Although C4 photosynthesis has the potential to drive faster growth rates(4,5), experiments directly comparing C3 and C4 plants have not shown consistent effects(1,6,7). This is problematic because differential growth is a crucial element of ecological theory(8,9) explaining C4 savannah responses to global change(10,11), and research to increase C3 crop productivity by introducing C4 photosynthesis(12). Here, we resolve this long-standing issue by comparing growth across 382 grass species, accounting for ecological diversity and evolutionary history. C4 photosynthesis causes a 19-88% daily growth enhancement. Unexpectedly, during the critical seedling establishment stage, this enhancement is driven largely by a high ratio of leaf area to mass, rather than fast growth per unit leaf area. C4 leaves have less dense tissues, allowing more leaves to be produced for the same carbon cost. Consequently, C4 plants invest more in roots than C3 species. Our data demonstrate a general suite of functional trait divergences between C3 and C4 species, which simultaneously drive faster growth and greater investment in water and nutrient acquisition, with important ecological and agronomic implications

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV