Impact of topographic internal lee wave drag on an eddying global ocean model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116868/1/ocemod_wavedrag_eddystatistics_trossmanetal_2016.pd

Impact of parameterized lee wave drag on the energy budget of an eddying global ocean model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100112/1/ocemod_wavedrag_2013.pd

Protocol for the ORION trial (RadiO fRequency ablatION for haemorrhoids): a randomised controlled trial

Background Haemorrhoids are common and can significantly impact the personal and working lives of individuals. Those with more severe symptoms and those not responding to conservative management may require surgery. Current surgical techniques are associated with a degree of postoperative discomfort which may delay return to normal activity. Recurrence is lower in more radical procedures but resulting pain is higher. Radiofrequency ablation (RFA) is a new technique that is gaining popularity and has several hypothesised benefits, including reduced pain and recurrence. However, available evidence is limited. A recent overview from the National Institute for Health and Clinical Excellence recommended more research, in the form of randomised controlled trials, be carried out before further investment is made by national health services. Our aim is to assess whether RFA is at least as good in terms of recurrence as existing surgical interventions, but superior in terms of pain, for patients with symptomatic grade II and III haemorrhoids. Methods The RadiO fRequency ablatION for haemorrhoids (ORION) trial will be a pragmatic multicentre patient/assessorblind parallel group-controlled trial with economic evaluation. The target sample size is 376 participants (188 per arm) and is based on two co-primary endpoints: (i) a non-inferiority design for recurrence and (ii) superiority design for pain at seven days. Participants with grade II or III haemorrhoids will be recruited in 16 National Health Service hospitals and randomised (1:1) to either RFA or surgeon’s choice of surgery. Conclusions Results will inform future practice for the treatment of grade II–III haemorrhoids and provide evidence for national health services on future investments in RFA

Formation of Subtropical Mode Water in a high-resolution ocean simulation of the Kuroshio Extension region

Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Ocean Modelling 17 (2007): 338-356, doi:10.1016/j.ocemod.2007.03.002.A high-resolution numerical model is used to examine the formation and variability of the North Pacific Subtropical ModeWater (STMW) over a 3-year period. The STMW distribution is found to be highly variable in both space and time, a characteristic often unexplored because of sparse observations or the use of coarse resolution simulations. Its distribution is highly dependent on eddies, and where it was renewed during the previous winter. Although the potential vorticity fluxes associated with down-front winds can be of the same order of magnitude or even greater than the diabatic ones due to air-sea temperature differences, the latter dominate the potential vorticity budget on regional and larger scales. Air-sea fluxes, however, are dominated by a few strong wind events, emphasizing the importance of short time scales in the formation of mode waters. In the Kuroshio Extension region, both advection and mixing play important roles to remove the STMW from the formation region.This work was sponsored by the National Science Foundation OCE-0220161 (S.J.) and OCE-0221781/0549225 (J.M.), the Office of Naval Research (J.M., M.M.), Department of Energy/CCPP (M.M.), and the Office of Science (BER), US Department of Energy, Grant No. DE-FG02-05ER64119 (J.M.)

Ocean turbulence, III : new GISS vertical mixing scheme

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Ocean Modelling 34 (2010): 70-91, doi:10.1016/j.ocemod.2010.04.006.We have found a new way to express the solutions of the RSM (Reynolds Stress Model) equations that allows us to present the turbulent diffusivities for heat, salt and momentum in a way that is considerably simpler and thus easier to implement than in previous work. The RSM provides the dimensionless mixing efficiencies Γα (α stands for heat, salt and momentum). However, to compute the diffusivities, one needs additional information, specifically, the dissipation ε. Since a dynamic equation for the latter that includes the physical processes relevant to the ocean is still not available, one must resort to different sources of information outside the RSM to obtain a complete Mixing Scheme usable in OGCMs. As for the RSM results, we show that the Γα’s are functions of both Ri and Rρ (Richardson number and density ratio representing double diffusion, DD); the Γα are different for heat, salt and momentum; in the case of heat, the traditional value Γh = 0.2 is valid only in the presence of strong shear (when DD is inoperative) while when shear subsides, NATRE data show that Γh can be three times as large, a result that we reproduce. The salt Γs is given in terms of Γh. The momentum Γm has thus far been guessed with different prescriptions while the RSM provides a well defined expression for Γm (Ri, Rρ). Having tested Γh, we then test the momentum Γm by showing that the turbulent Prandtl number Γm/Γh vs. Ri reproduces the available data quite well. As for the dissipation ε, we use different representations, one for the mixed layer (ML), one for the thermocline and one for the ocean’s bottom. For the ML, we adopt a procedure analogous to the one successfully used in PB (planetary boundary layer) studies; for the thermocline, we employ an expression for the variable εN-2 from studies of the internal gravity waves spectra which includes a latitude dependence; for the ocean bottom, we adopt the enhanced bottom diffusivity expression used by previous authors but with a state of the art internal tidal energy formulation and replace the fixed Γα = 0.2 with the RSM result that brings into the problem the Ri,Rρ dependence of the Γα; the unresolved bottom drag, which has thus far been either ignored or modeled with heuristic relations, is modeled using a formalism we previously developed and tested in PBL studies. We carried out several tests without an OGCM. Prandtl and flux Richardson numbers vs. Ri. The RSM model reproduces both types of data satisfactorily. DD and Mixing efficiency Γh (Ri, Rρ). The RSM model reproduces well the NATRE data. Bimodal ε-distribution. NATRE data show that ε (Ri1), which our model reproduces. Heat to salt flux ratio. In the Ri>>1 regime, the RSM predictions reproduce the data satisfactorily. NATRE mass diffusivity. The z-profile of the mass diffusivity reproduces well the measurements at NATRE. The local form of the mixing scheme is algebraic with one cubic equation to solve

Postoperative complications after procedure for prolapsed hemorrhoids (PPH) and stapled transanal rectal resection (STARR) procedures

Procedure for prolapsing hemorrhoids (PPH) and stapled transanal rectal resection for obstructed defecation (STARR) carry low postoperative pain, but may be followed by unusual and severe postoperative complications. This review deals with the pathogenesis, prevention and treatment of adverse events that may occasionally be life threatening. PPH and STARR carry the expected morbidity following anorectal surgery, such as bleeding, strictures and fecal incontinence. Complications that are particular to these stapled procedures are rectovaginal fistula, chronic proctalgia, total rectal obliteration, rectal wall hematoma and perforation with pelvic sepsis often requiring a diverting stoma. A higher complication rate and worse results are expected after PPH for fourth-degree piles. Enterocele and anismus are contraindications to PPH and STARR and both operations should be used with caution in patients with weak sphincters. In conclusion, complications after PPH and STARR are not infrequent and may be difficult to manage. However, if performed in selected cases by skilled specialists aware of the risks and associated diseases, some complications may be prevented

WGS-based telomere length analysis in Dutch family trios implicates stronger maternal inheritance and a role for RRM1 gene

Telomere length (TL) regulation is an important factor in ageing, reproduction and cancer development. Genetic, hereditary and environmental factors regulating TL are currently widely investigated, however, their relative contribution to TL variability is still understudied. We have used whole genome sequencing data of 250 family trios from the Genome of the Netherlands project to perform computational measurement of TL and a series of regression and genome-wide association analyses to reveal TL inheritance patterns and associated genetic factors. Our results confirm that TL is a largely heritable trait, primarily with mother’s, and, to a lesser extent, with father’s TL having the strongest influence on the offspring. In this cohort, mother’s, but not father’s age at conception was positively linked to offspring TL. Age-related TL attrition of 40 bp/year had relatively small influence on TL variability. Finally, we have identified TL-associated variations in ribonuclease reductase catalytic subunit M1 (RRM1 gene), which is known to regulate telomere maintenance in yeast. We also highlight the importance of multivariate approach and the limitations of existing tools for the analysis of TL as a polygenic heritable quantitative trait