TBM Challenges on Musaimeer outfall tunnel

Musaimeer outfall tunnel is the longest outfall tunnel in the Middle East. The tunnel was excavated by Earth Pressure Balance (EPB), Tunnel Boring Machine (TBM) and encountered three distinct rock masses namely Rus Formation, Midra-Shale, and Simsima Limestone along with water inflows at high pressure, complex mixed ground, and weaker ground strata prone to cavities with the presence of vertical and lateral fractures connected to the seabed. These conditions resulted in the TBM operating in very dry conditions where the addition of soil conditioners and water sprayed in the excavations chamber and cutter head were required to avoid clogging situations and create a pasty excavation material, which impacted TBM operation. The opposite scenario occurred when the TBM encountered very wet conditions while passing through weathered Simsima Limestone fully connected hydrostatically with the seabed. Such situations directly impacted the productions rates, quantities of consumables, extra cost on the tunnel enabling activities and finally, the need of both atmospheric and hyperbaric interventions into the cutter head up to 3.5 bar to replace cutting tools. Long tunnels with only one access shaft pose many programme problems for logistics, combine these with the requirement to drive directly out under the seabed for 10.2 km, and the programme issues become even more challenging. To meet and eventually improve on the planned completion date required a complex and extensive management of all tunnel logistics activities required to support consistent tunnelling for a two-year period. This technical paper will discuss the management issues and solutions implemented to meet the challenges of the outfall tunnel construction

Diffuser Bed Construction Challenges on the Musaimeer Pump Station and Outfall Project

Musaimeer Pump Station and Outfall project (MPSO) is a strategically important drainage asset initiated, developed, and completed by Ashghal in 2022. This project accommodates ground and storm water received from the drainage networks of 270 km2 of urban areas in southern Doha, along with storm protection for four soccer stadiums used during the FIFA 2022 World Cup. The key elements of this project were a pump station with a capacity of 19.7 m³ / s, one of the longest ground and storm water tunnels in the world with a total length of 10.2 km and the diffuser bed structure measuring 194 m x 40 m. The diffuser bed structure is connected to the outfall tunnel by a riser shaft and is the structure used to disperse the ground and storm water in a controlled manner and in accordance with environmental standards. This technical paper will detail the entire process from dredging and material stockpiling, riser shaft drilling and construction, diffuser bed fabrication onshore, transportation to final location, installation on the sea floor, backfilling and protection works and finally commissioning of the entire project

Expansion and Activation Kinetics of Immune Cells during Early Phase of GVHD in Mouse Model Based on Chemotherapy Conditioning

In the present paper, we have investigated early pathophysiological events in graft-versus-host disease (GVHD), a major complication to hematopoietic stem cell transplantation (HSCT). BLLB/c female mice conditioned with busulfan/cyclophosphamide (Bu-Cy) were transplanted with allogeneic male C57BL/6. Control group consisted of syngeneic transplanted Balb/c mice. In allogeneic settings, significant expansion and maturation of donor dendritic cells (DCs) were observed at day +3, while donor T-cells CD8+ were increased at day +5 (230%) compared to syngeneic HSCT. Highest levels of inflammatory cytokines IL-2, IFN-gamma, and TNF-alfa at day +5 matched T-cell activation. Concomitantly naïve T-cells gain effecr-memory phenotype and migrated from spleen to peripheral lymphoid organs. Thus, in the very early phase of GHVD following Bu-Cy conditioning donor, DCs play an important role in the activation of donor T cells. Subsequently, donor naïve T-cells gain effector-memory phenotype and initiate GVHD

Incidence of intraocular lens exchange after cataract surgery

Intraocular lens (IOL) exchange after cataract surgery is unusual but may be associated with suboptimal visual outcome. The incidence of IOL exchange has not been consistently estimated. Such information is invaluable when counseling patients prior to cataract surgery. We examined the incidence of, and indications and risk factors for, IOL exchange after cataract surgery. We also assessed visual outcome of eyes that had an IOL exchange. A cohort design was used to estimate the incidence of IOL exchange and a case-control design to identify factors associated with it. All phacoemulsification surgeries with IOL (n = 17415 eyes) during 2010-2017 and those that had a subsequent IOL removal or replacement during the same time period were identified (n = 34 eyes). The incidence of IOL exchange was 2 per 1000 surgeries (95% confidence interval [CI] 1 to 3) over 8 years. Eyes that underwent subsequent IOL removal or replacement were compared with eyes that had cataract surgery only (n = 47) across demographic and clinical characteristics. In a binary logistic regression analysis, two factors were significantly associated with IOL exchange/removal: an adverse event during cataract surgery (adjusted odds ratio [aOR] 19.45; 95% CI 4.89-77.30, P \u3c 0.001) and a pre-existing ocular comorbidity (aOR 10.70; 95% CI 1.69-67.63, P = 0.021). The effect of gender was marginally significant (P = 0.077). Eyes that underwent IOL exchange or explantation were nearly two and a half times more likely to have a final best-corrected visual acuity of \u3c20/60 compared to those that had cataract surgery alone (adjusted RR 2.60 95% CI, 1.13-6.02; P = 0.025)

Tuberculosis control in prisons: current situation and research gaps

Background: Tuberculosis (TB) in penitentiary services (prisons) is a major challenge to TB control. This review article describes the challenges that prison systems encounter in TB control and provides solutions for the more efficient use of limited resources based on the three pillars of the post-2015 End TB Strategy. This paper also proposes research priorities for TB control in prisons based on current challenges. Methods: Articles (published up to 2011) included in a recent systematic review on TB control in prisons were further reviewed. In addition, relevant articles in English (published 1990 to May 2014) were identified by searching keywords in PubMed and Google Scholar. Article bibliographies and conference abstracts were also hand-searched. Results: Despite being a serious cause of morbidity and mortality among incarcerated populations, many prison systems encounter a variety of challenges that hinder TB control. These include, but are not limited to, insufficient laboratory capacity and diagnostic tools, interrupted supply of medicines, weak integration between civilian and prison TB services, inadequate infection control measures, and low policy priority for prison healthcare. Conclusions: Governmental commitment, partnerships, and sustained financing are needed in order to facilitate improvements in TB control in prisons, which will translate to the wider community

The global oscillation network group site survey. II. Results

The Global Oscillation Network Group (GONG) Project will place a network of instruments around the world to observe solar oscillations as continuously as possible for three years. The Project has now chosen the six network sites based on analysis of survey data from fifteen sites around the world. The chosen sites are: Big Bear Solar Observatory, California; Mauna Loa Solar Observatory, Hawaii; Learmonth Solar Observatory, Australia; Udaipur Solar Observatory, India; Observatorio del Teide, Tenerife; and Cerro Tololo Interamerican Observatory, Chile. Total solar intensity at each site yields information on local cloud cover, extinction coefficient, and transparency fluctuations. In addition, the performance of 192 reasonable components analysis. An accompanying paper describes the analysis methods in detail; here we present the results of both the network and individual site analyses. The selected network has a duty cycle of 93.3%, in good agreement with numerical simulations. The power spectrum of the network observing window shows a first diurnal sidelobe height of 3 × 10⁻⁴ with respect to the central component, an improvement of a factor of 1300 over a single site. The background level of the network spectrum is lower by a factor of 50 compared to a single-site spectrum

Common symptoms during pregnancy to predict depression and health status 14 years post partum

Objective: To examine the prospective association between symptoms commonly experienced during pregnancy and the mental and general health status of women 14 years post partum. Methods: Data used were from the Mater-University of Queensland Study of Pregnancy, a community-based prospective birth cohort study begun in Brisbane, Australia, in 1981. Logistic regression analyses were conducted. Results: Data were available for 5118 women. Women who experienced a higher burden of symptoms during pregnancy were at greater risk of becoming depressed and reporting poorer health status 14 years post partum. Women who experienced major problems during pregnancy were 4 times more likely to be depressed and nearly 8 times more likely to report poorer health status 14 years after the index pregnancy compared with women who experienced few problems. Conclusions: Findings suggest that pregnant women who experience common symptoms during pregnancy are likely to experience poorer mental and self-reported general health 14 years after the pregnancy. (C) 2008 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved

Risk factor studies of age-at-onset in a sample ascertained for Parkinson disease affected sibling pairs: a cautionary tale

An association between exposure to a risk factor and age-at-onset of disease may reflect an effect on the rate of disease occurrence or an acceleration of the disease process. The difference in age-at-onset arising from case-only studies, however, may also reflect secular trends in the prevalence of exposure to the risk factor. Comparisons of age-at-onset associated with risk factors are commonly performed in case series enrolled for genetic linkage analysis of late onset diseases. We describe how the results of age-at-onset studies of environmental risk factors reflect the underlying structure of the source population, rather than an association with age-at-onset, by contrasting the effects of coffee drinking and cigarette smoking on Parkinson disease age-at-onset with the effects on age-at-enrollment in a population based study sample. Despite earlier evidence to suggest a protective association of coffee drinking and cigarette smoking with Parkinson disease risk, the age-at-onset results are comparable to the patterns observed in the population sample, and thus a causal inference from the age-at-onset effect may not be justified. Protective effects of multivitamin use on PD age-at-onset are also shown to be subject to a bias from the relationship between age and multivitamin initiation. Case-only studies of age-at-onset must be performed with an appreciation for the association between risk factors and age and ageing in the source population

Recent cadmium exposure among male partners may affect oocyte fertilization during in vitro fertilization (IVF)

We recently reported evidence suggesting associations between urine cadmium concentrations, reflecting long-term exposure, measured in 25 female patients (relative risk = 1.41, P = 0.412) and 15 of their male partners (relative risk = 0.19, P = 0.097) and oocyte fertilization in vitro. Blood cadmium concentrations reflect more recent exposure. We here incorporate those measures into our prior data set and employ multivariable log-binomial regression models to generate hypotheses concerning the relative effects of long-term and recent cadmium exposure on oocyte fertilization in vitro. No association is indicated for blood cadmium from women and oocyte fertilization, adjusted for urine cadmium and creatinine, blood lead and mercury, age, race/ethnicity and cigarette smoking (relative risk = 0.88, P = 0.828). However, we suggest an inverse adjusted association between blood cadmium from men and oocyte fertilization (relative risk = 0.66, P = 0.143). These results suggest that consideration of long-term and recent exposures are both important for assessing the effect of partner cadmium levels on oocyte fertilization in vitro