1,796 research outputs found
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An extended ice-Age sea-level equation: Incorporating water flux across sills
Summary
We present a generalized theory governing gravitationally self-consistent, spatio-temporal sea-level changes within an ocean-plus-lake system that is intermittently connected by water mass flux across a sill. Our expressions for the change in sea level (defined as the difference in height of the sea surface equipotential relative to the solid surface) hold for any Earth model, and easily incorporate effects of viscoelastic deformation of the solid Earth and perturbations in both the gravitational field and rotation vector (as is now standard in ice-age sea-level calculations). In its most general form, the theory also includes an exact treatment of the evolving shoreline position in both water bodies. Our formalism involves three cases: (1) one global ocean, in which mass transfer may occur between ice sheets and the global ocean; (2) an ocean and lake separated by an exposed sill, in which mass transfer may occur between ice sheets and the global ocean, and between the ocean and lake via evaporative flux; and (3) transitional phases between these two states, when the ocean surface reaches the height of the sill from below (i.e., the sill is breached) or above (the sill is exposed). We illustrate the new theory using examples from the Black Sea flooding during the last deglacial phase (∼10 ka) and sea-level fall in the Mediterranean Sea during the Messinian Salinity Crisis (5.96-5.33 Ma). These examples demonstrate the importance of including the geophysical feedbacks associated with sea-level change in an isolated basin in the dynamics of flooding and desiccation.</jats:p
Progress in nutrition related millennium development goals in Uganda before adoption of post-2015 development agenda: review of goals 1, 2 and 4
Promulgation of Millennium Development Goals (MDG) in year 2000 gave hope to the world that common interests and challenges such as poverty and hunger, education, gender equality and women empowerment, child mortality and maternal health, diseases such as, HIV/AIDS, malaria, environmental sustainability, as well as global partnerships that were affecting the world could, respectively, be prioritized and responded to within a timeframe of the year 2001 to 2015. In this case, the developing countries like Uganda were accorded great attention. Nutrition has been at the forefront of the MDG implementation as one of the daunting challenges affecting developing countries. This paper is based on a narrative review of quantitative and qualitative data aimed at establishing the progress Uganda made towards achieving the three nutrition related MDG (1, 2 and 4). A timeframe of 2001 when the goals were officially launched up to the deadline of 31st December 2015 and the adoption of the Post-2015 Development Agenda was considered. The majority of Low and Middle Income Developing Countries (LMIDCS) failed to make substantial progress in achieving most of the goals, including the nutrition related goals. Uganda only achieved MDG one - target 1.A indicator of halving a proportion of people living below less than $ 1.25 a day. To some extent, this helped in alleviating poverty, creating jobs, and generating income and saving and other opportunities which are indeed catalysts to human development and socioeconomic wellbeing. Unfortunately, Uganda missed achieving the rest of the nutrition related MDG. They included: reducing underweight children under five years (MDG 1.8), increasing net enrollment of boys and girls in primary education (MDG 2.1), increasing proportion of pupils starting grade one to last primary grade (MDG 2.2), reducing child mortality rate per 1,000 live births (MDG 4.1) and reducing infant mortality rate per 1,000 live births (MDG 4.2). However, the hope at this particular moment ought to be directed towards tracking and achieving goals in the Post-2015 Development Agenda whose aim is mainly to build on the progress of the MDG.Key words: Nutrition, Millennium Development Goals, Post-Development Agenda, Ugand
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Forward and inverse modelling of post-seismic deformation
We consider a new approach to both the forward and inverse problems in post-seismic deformation. We present a method for forward modelling post-seismic deformation in a self-gravitating, heterogeneous and compressible earth with a variety of linear and nonlinear rheologies. We further demonstrate how the adjoint method can be applied to the inverse problem both to invert for rheological structure and to calculate the sensitivity of a given surface measurement to changes in rheology or time-dependence of the source. Both the forward and inverse aspects are illustrated with several numerical examples implemented in a spherically symmetric earth model.Natural Environment Research Council, British Antarctic Surve
Global dynamic topography observations reveal limited influence of large-scale mantle flow
Convective circulation of the Earth’s mantle maintains some fraction of surface topography that varies with space and time. Most predictive models show that this dynamic topography has peak amplitudes of about ±2km, dominated by wavelengths of 10⁴km. Here, we test these models against our comprehensive observational database of 2,120 spot measurements of dynamic topography that were determined by analysing oceanic seismic surveys. These accurate measurements have typical peak amplitudes of ±1km and wavelengths of approximately 10³km, and are combined with limited continental constraints to
generate a global spherical harmonic model whose robustness has been carefully tested and benchmarked. Our power spectral analysis reveals significant discrepancies between observed and predicted dynamic topography. At longer wavelengths (such as 10⁴km), observed dynamic topography has peak amplitudes of about ±500m. At shorter wavelengths (such as 10³km), significant dynamic topography is still observed. We show that these discrepancies can be explained if short-wavelength dynamic topography is generated by temperature-driven density anomalies within a sub-plate asthenospheric channel. Stratigraphic observations from adjacent continental margins show that these dynamic topographic signals evolve quickly with time. More rapid temporal and spatial changes in vertical displacement of the Earth’s surface have direct consequences for fields as diverse as mantle flow, oceanic circulation and long-term climate change
Enhanced neutralising antibody response to bovine viral diarrhoea virus (BVDV) induced by DNA vaccination in calves
DNA vaccination is effective in inducing potent immunity in mice; however it appears to be less so in large animals. Increasing the dose of DNA plasmid to activate innate immunity has been shown to improve DNA vaccine adaptive immunity. Retinoic acid-inducible gene I (RIG-I) is a critical cytoplasmic double-stranded RNA pattern receptor required for innate immune activation in response to viral infection. RIG-I recognise viral RNA and trigger antiviral response, resulting in type I interferon (IFN) and inflammatory cytokine production. In an attempt to enhance the antibody response induced by BVDV DNA in cattle, we expressed BVDV truncated E2 (E2t) and NS3 codon optimised antigens from antibiotic free-plasmid vectors expressing a RIG-I agonist and designated either NTC E2t(co) and NTC NS3(co). To evaluate vaccine efficacy, groups of five BVDV-free calves were intramuscularly injected three times with NTC E2t(co) and NTC NS3(co) vaccine plasmids individually or in combination. Animals vaccinated with our (previously published) conventional DNA vaccines pSecTag/E2 and pTriExNS3 and plasmids expressing RIG-I agonist only presented both the positive and mock-vaccine groups. Our results showed that vaccines coexpressing E2t with a RIG-I agonist induced significantly higher E2 antigen specific antibody response (p < 0.05). Additionally, E2t augmented the immune response to NS3 when the two vaccines were delivered in combination. Despite the lack of complete protection, on challenge day 4/5 calves vaccinated with NTC E2t(co) alone or NTC E2t(co) plus NTC NS3(co) had neutralising antibody titres exceeding 1/240 compared to 1/5 in the mock vaccine control group. Based on our results we conclude that co-expression of a RIG-I agonist with viral antigen could enhance DNA vaccine potency in cattle
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Anelasticity across seismic to tidal timescales: a self-consistent approach
In a pioneering study, Wahr & Bergen developed the widely adopted, pseudo-normal mode framework for predicting the impact of anelastic effects on the Earth's body tides. Lau have recently derived an extended normal mode treatment of the problem (as well as a minor variant of the theory known as the direct solution method) that makes full use of theoretical developments in free oscillation seismology spanning the last quarter century and that avoids a series of assumptions and approximations adopted in the traditional theory for predicting anelastic effects. There are two noteworthy differences between these two theories: (1) the traditional theory only considers perturbations to the eigenmodes of an elastic Earth, whereas the new theory augments this set of modes to include the relaxation modes that arise in anelastic behaviour; and (2) the traditional theory approximates the complex perturbation to the tidal Love number as a scaled version of the complex perturbation to the elastic moduli, whereas the new theory computes the full complex perturbation to each eigenmode. In this study, we highlight the above differences using a series of synthetic calculations, and demonstrate that the traditional theory can introduce significant error in predictions of the complex perturbation to the Love numbers due to anelasticity and the related predictions of tidal lag angles. For the simplified Earth models we adopt, the computed lag angles differ by ∼20 per cent. The assumptions in the traditional theory have important implications for previous studies that use model predictions to correct observables for body tide signals or that analyse observations of body tide deformation to infer mantle anelastic structure. Finally, we also highlight the fundamental difference between apparent attenuation (i.e. attenuation inferred from observations or predicted using the above theories) and intrinsic attenuation (i.e. the material property investigated through experiments), where both are often expressed in terms of lag angles or . In particular, we demonstrate the potentially significant (factor of two or more) bias introduced in estimates of and its frequency dependence in studies that have treated determined from tidal phase lags or measured experimentally as being equal. The observed or theoretically predicted lag angle (or apparent ) differs from the intrinsic, material property due to inertia, self-gravity and effects associated with the energy budget. By accounting for these differences we derive, for a special case, an expression that accurately maps apparent attenuation predicted using the extended normal mode formalism of Lau into intrinsic attenuation. The theory allows for more generalized mappings which may be used to robustly connect observations and predictions of tidal lag angles to results from laboratory experiments of mantle materials.This work was supported by NSF EAR-1464024, NSF EAR-1215061, and Harvard University
Reciprocity and sensitivity kernels for sea level fingerprints
Reciprocity theorems are established for the elastic sea level fingerprint
problem including rotational feedbacks. In their simplest form, these results
show that the sea level change at a location x due to melting a unit point mass
of ice at x' is equal to the sea level change at x' due to melting a unit point
mass of ice at x. This identity holds irrespective of the shoreline geometry or
of lateral variations in elastic Earth structure. Using the reciprocity
theorems, sensitivity kernels for sea level and related observables with
respect to the ice load can be readily derived. It is notable that calculation
of the sensitivity kernels is possible using standard fingerprint codes, though
for some types of observable a slight generalisation to the fingerprint problem
must be considered. These results are of use within coastal hazard assessment
and have a range of potential applications within studies of modern-day sea
level change.Comment: Paper submitted to Geophysical Journal Internationa
Gene Expression and Methylation Levels of PCSK9 Gene in Iraqi Patients with Coronary Artery Disease
يرتبط التعبير الجيني لجين PCSK9ارتباطًا وثيقًا بمستويات الدهون وخطر الإصابة بمرض تصلب الشرايين التاجية. تهدف الدراسة الحالية إلى قياس كمية التعبير الجيني للجين PCSK9 وتأثير المثيلة على مستوى تعبيره الذي يساهم في التسبب في اضطراب الشريان التاجي الحاد.
تضمنت الدراسة الحالية 150 شخصًا من المجتمع العراقي ، 100 مريض بمرض الشريان التاجي و 50 من الأصحاء. تم تحديد تركيز PCSK9 في كل عينات المصل المدروسة بواسطة تقنية ELISA ، وتم تقدير مستويات التعبير عن جين PCSK9 في الدم الكامل بطريقة qRT-PCR ، واكتشاف مستوى مثيلة الحمض النووي في جين PCSK9 باستخدام تقنية HRM-PCR.
كان التعبير عن جين ب مستوى اعلى PCSK9 6.06 ± 1.84 في مجموعة مرضى ASCAD مقارنة بمجموعة التحكم 1.00 ± 0.19. أيضا كان تركيز بروتين PCSK9 عالياً في مجموعة المرضى مقارنة بمجموعة الاصحاء P = <0.01. فضلا عن ان مستويات مثيلة PCSK9 ، اظهرت فرقاً معنوياً بين مجموعتي الدراسة بمستوى 0.002P=. في الختام ، ترتبط مستويات بروتين PCSK9 في المصل بمرض الشريان التاجي كما موضح في receiver operating characteristic (ROC) analysis ، مما يؤدي إلى اعتبار أن تركيز بروتين PCSK9 قد يكون مؤشرًا جيدًا لتطور مرض الشريان التاجي.The expression of the Proprotein Convertase Subtilisin/Kexin Type 9 gene (PCSK9) is inextricably related to lipid levels and a risk of atherosclerotic coronary artery disease (ASCAD). The present study aims to measure the quantity of PCSK9 gene expression and the effect of methylation on its expression level taking part in the pathogenesis of acute coronary artery disorder.
A current study included 150 subjects from the Iraqi population, 100 ASCAD patients and 50 healthy controls. The concentration of PCSK9 in each serum sample was determined by the ELISA technique, the expression levels of the PCSK9 gene in whole blood were estimated by RT-qPCR – Quantitative Reverse Transcription PCR method, and DNA methylation level detection in PCSK9 gene by using High Resolution Melting Analysis (HRM) technique.
The expression level of the PCSK9 gene was 6.06 ± 1.84 in ASCAD patients group compared with a control group 1.00 ±0.19. That indicates the up-regulation of the PCSK9 gene in patient with atherosclerosis. In addition, the PCSK9 concentration was higher in patient group in comparison to the healthy controls group P= < 0.01. However, PCSK9 methylation levels, a highly significant distinction between the two study groups p=0.002. In conclusion, serum PCSK9 levels are associated with coronary artery lesions as shown in receiver operating characteristic (ROC) analysis. Suggests that, serum PCSK9 might be a good indicator of coronary artery disease development
The Importance of Self-Management in the Context of Personalized Care in COPD
Despite current guidelines and decades of evidence on the benefits of a self-management approach, self-management of COPD remains relatively under-utilized in clinical care compared with other chronic diseases. However, self-management interventions can play a valuable role in supporting people with COPD to respond to changing symptoms, and thereby make appropriate decisions regarding the management of their own chronic condition. In this review, we discuss the history and evolution of the concept of self-management, assess current multidisciplinary support programs and clinical interactions designed to optimize self-management, and reflect on how effective these are in terms of clinical and humanistic outcomes. We also evaluate the mechanisms for encouraging change from protocol-based care towards a more personalized care approach, and discuss the role of digital self-management interventions and the importance of addressing health inequalities in COPD treatment, which have been accelerated by the COVID-19 pandemic. Reflecting on the importance of self-management in the context of symptom monitoring and provision of educational support, including information from patient organizations and charities, we discuss the ideal components of a self-management plan for COPD and provide six key recommendations for its implementation: 1) better education for healthcare professionals on disease management and consultation skills; 2) new targets and priorities for patient-focused outcomes; 3) skills gap audits to identify barriers to self-management; 4) best practice sharing within primary care networks and ongoing professional development; 5) enhanced initial consultations to establish optimal self-management from the outset; and 6) negotiation and sharing of self-management plans at the point of diagnosis
The effect of face velocity, pleat density and pleat orientation on the most penetrating particle size, pressure drop and fractional efficiency of HEPA filters
The increasing need for clean air in critical industrial applications has highlighted the importance of the role of air filters in providing improved air quality. Actual performance of air filters installed in air handling units and in the intake of gas turbines tends to deviate from the performance predicted by laboratory results. Therefore, accurate filter performance prediction is important to estimate filter lifetime, and to reduce energy and maintenance operating costs. To ensure that the desired efficiency of a HEPA filter is attained, the effects of face velocity, pleat density and pleat orientation on the Most Penetrating Particle Size (MPPS) of pleated HEPA filters must be examined. This paper compares the effects of varying these parameters on the MPPS. The paper also presents the initial pressure drop response and fractional efficiency curves using DEHS testing according to DIN 1822 for vertical and horizontal pleat orientations. It analyzes the underlying reasons causing surface area losses for different flow rates, pleat density and orientation as well as the effects on filter permeability. The tests conducted in this study used full scale HEPA pleated V-shaped filters from Heating Ventilation and Air Conditioning (HVAC) and gas turbine applications
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