Clarifications of a Datum Axis or Centerplane Specifying in Maximum Material Condition of Geometric Dimensioning and Tolerancing

Engineering and Engineering Technology students and professionals learning the processes and standards in computer-aided design (CAD) and computer-aided manufacturing (CAM) should learn and understand the methodology of geometric dimensioning and tolerancing (GD&T) to describe the intent and requirements for part and assembly geometries. Correct application of GD&T ensures that the part and assembly geometry defined on the drawing will have the desired form and fit (within limits) and function as intended. One learning difficulty in understanding GD&T is the concept of defining a datum axis or center plane using Maximum Material Condition (MMC). To overcome this difficulty, a new approach is presented that uses a modifier ○V (Virtual Condition) instead of ○M (MMC). A thorough rationalization of using ○V in datum axis specification is discussed. The paper also provides a convenient table on how to use this modifier

Implementing Mechatronics Design Methodology in Mechanical Engineering Technology Senior Design Projects at the Old Dominion University

In recent years, the nature of engineering design has changed due to advances in embedded system design and computer technologies. It is rare to engineer a purely mechanical design that does not incorporate electrical and electronic components. Mechanical engineers and mechanical engineering technologists must possess a multi-disciplinary knowledge with the understanding of both mechanical and electrical systems. For this purpose, undergraduate programs in engineering technology have added mechatronics courses to their curriculum. Mechatronics is a design process that is multi-disciplinary in nature and integrates principles of many engineering disciplines including, but not limited to, mechanical engineering, electrical engineering, and controls engineering. These courses typically incorporate problem-based learning and project-based pedagogy to effectively build the student’s knowledge and understanding. Old Dominion University’s Mechanical Engineering Technology (ODU MET) program offers undergraduate courses related to Advanced Manufacturing including Robotics; Automation; Lean Manufacturing; Computer Integrated Manufacturing; and Advanced Manufacturing Processes. Recently, two new courses related to mechatronics were added to the same focus area. In addition, ODU MET program has placed an increased emphasis on mechatronics for students’ senior design projects. This paper highlights the benefits of including mechatronics in the ODU MET curriculum and presents several recent senior design projects that showcase how the student has incorporated multi-disciplinary principles into the design and build of a functional mechatronic device. By embedding these experience into their senior design project, students are exposed to other engineering technology areas, learn the terminology of other professions, and feel more confident to join the workforce with the cross-disciplinary skills needed to be successful

Simultaneous quantification of 12 different nucleotides and nucleosides released from renal epithelium and in human urine samples using ion-pair reversed-phase HPLC

Nucleotides and nucleosides are not only involved in cellular metabolism but also act extracellularly via P1 and P2 receptors, to elicit a wide variety of physiological and pathophysiological responses through paracrine and autocrine signalling pathways. For the first time, we have used an ion-pair reversed-phase high-performance liquid chromatography ultraviolet (UV)-coupled method to rapidly and simultaneously quantify 12 different nucleotides and nucleosides (adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, adenosine, uridine triphosphate, uridine diphosphate, uridine monophosphate, uridine, guanosine triphosphate, guanosine diphosphate, guanosine monophosphate, guanosine): (1) released from a mouse renal cell line (M1 cortical collecting duct) and (2) in human biological samples (i.e., urine). To facilitate analysis of urine samples, a solid-phase extraction step was incorporated (overall recovery rate ? 98 %). All samples were analyzed following injection (100 ?l) into a Synergi Polar-RP 80 Å (250 × 4.6 mm) reversed-phase column with a particle size of 10 ?m, protected with a guard column. A gradient elution profile was run with a mobile phase (phosphate buffer plus ion-pairing agent tetrabutylammonium hydrogen sulfate; pH 6) in 2-30 % acetonitrile (v/v) for 35 min (including equilibration time) at 1 ml min(-1) flow rate. Eluted compounds were detected by UV absorbance at 254 nm and quantified using standard curves for nucleotide and nucleoside mixtures of known concentration. Following validation (specificity, linearity, limits of detection and quantitation, system precision, accuracy, and intermediate precision parameters), this protocol was successfully and reproducibly used to quantify picomolar to nanomolar concentrations of nucleosides and nucleotides in isotonic and hypotonic cell buffers that transiently bathed M1 cells, and urine samples from normal subjects and overactive bladder patients

Bax and Bak function as the outer membrane component of the mitochondrial permeability pore in regulating necrotic cell death in mice

A critical event in ischemia-based cell death is the opening of the mitochondrial permeability transition pore (MPTP). However, the molecular identity of the components of the MPTP remains unknown. Here, we determined that the Bcl-2 family members Bax and Bak, which are central regulators of apoptotic cell death, are also required for mitochondrial pore-dependent necrotic cell death by facilitating outer membrane permeability of the MPTP. Loss of Bax/Bak reduced outer mitochondrial membrane permeability and conductance without altering inner membrane MPTP function, resulting in resistance to mitochondrial calcium overload and necrotic cell death. Reconstitution with mutants of Bax that cannot oligomerize and form apoptotic pores, but still enhance outer membrane permeability, permitted MPTP-dependent mitochondrial swelling and restored necrotic cell death. Our data predict that the MPTP is an inner membrane regulated process, although in the absence of Bax/Bak the outer membrane resists swelling and prevents organelle rupture to prevent cell death

Discontinuous Galerkin methods for nonlinear scalar hyperbolic conservation laws: divided difference estimates and accuracy enhancement

In this paper, an analysis of the accuracy-enhancement for the discontinuous Galerkin (DG) method applied to one-dimensional scalar nonlinear hyperbolic conservation laws is carried out. This requires analyzing the divided difference of the errors for the DG solution. We therefore first prove that the alpha-th order (1 <= \alpha <= k+1) divided difference of the DG error in the L2-norm is of order k+(3-alpha)/2 when upwind fluxes are used, under the condition that |f'(u)| possesses a uniform positive lower bound. By the duality argument, we then derive superconvergence results of order k+(3-alpha)/2 in the negative-order norm, demonstrating that it is possible to extend the Smoothness-Increasing Accuracy-Conserving filter to nonlinear conservation laws to obtain at least (3k/2+1)th order superconvergence for post-processed solutions. As a by-product, for variable coefficient hyperbolic equations, we provide an explicit proof for optimal convergence results of order k+1 in the L2-norm for the divided differences of DG errors and thus (2k+1)th order superconvergence in negative-order norm holds. Numerical experiments are given that confirm the theoretical results

Novel Role for the AnxA1-Fpr2/ALX Signaling Axis as a Key Regulator of Platelet Function to Promote Resolution of Inflammation

Background: Ischemia reperfusion injury (I/RI) is a common complication of cardiovascular diseases. Resolution of detrimental I/RI-generated prothrombotic and proinflammatory responses is essential to restore homeostasis. Platelets play a crucial part in the integration of thrombosis and inflammation. Their role as participants in the resolution of thromboinflammation is underappreciated; therefore we used pharmacological and genetic approaches, coupled with murine and clinical samples, to uncover key concepts underlying this role. Methods: Middle cerebral artery occlusion with reperfusion was performed in wild-type or annexin A1 (AnxA1) knockout (AnxA1-/-) mice. Fluorescence intravital microscopy was used to visualize cellular trafficking and to monitor light/dye-induced thrombosis. The mice were treated with vehicle, AnxA1 (3.3 mg/kg), WRW4 (1.8 mg/kg), or all 3, and the effect of AnxA1 was determined in vivo and in vitro. Results: Intravital microscopy revealed heightened platelet adherence and aggregate formation post I/RI, which were further exacerbated in AnxA1-/- mice. AnxA1 administration regulated platelet function directly (eg, via reducing thromboxane B2 and modulating phosphatidylserine expression) to promote cerebral protection post-I/RI and act as an effective preventative strategy for stroke by reducing platelet activation, aggregate formation, and cerebral thrombosis, a prerequisite for ischemic stroke. To translate these findings into a clinical setting, we show that AnxA1 plasma levels are reduced in human and murine stroke and that AnxA1 is able to act on human platelets, suppressing classic thrombin-induced inside-out signaling events (eg, Akt activation, intracellular calcium release, and Ras-associated protein 1 [Rap1] expression) to decrease IIbβ3 activation without altering its surface expression. AnxA1 also selectively modifies cell surface determinants (eg, phosphatidylserine) to promote platelet phagocytosis by neutrophils, thereby driving active resolution. (n=5-13 mice/group or 7-10 humans/group.) Conclusions: AnxA1 affords protection by altering the platelet phenotype in cerebral I/RI from propathogenic to regulatory and reducing the propensity for platelets to aggregate and cause thrombosis by affecting integrin (IIbβ3) activation, a previously unknown phenomenon. Thus, our data reveal a novel multifaceted role for AnxA1 to act both as a therapeutic and a prophylactic drug via its ability to promote endogenous proresolving, antithromboinflammatory circuits in cerebral I/RI. Collectively, these results further advance our knowledge and understanding in the field of platelet and resolution biology.Fil: Senchenkova, Elena Y.. State University of Louisiana; Estados UnidosFil: Ansari, Junaid. State University of Louisiana; Estados UnidosFil: Becker, Felix. University Hospital Muenster; AlemaniaFil: Vital, Shantel A.. State University of Louisiana; Estados UnidosFil: Al-Yafeai, Zaki. State University of Louisiana; Estados UnidosFil: Sparkenbaugh, Erica M.. University North Carolina Chapel Hill; Estados UnidosFil: Pawlinski, Rafal. University North Carolina Chapel Hill; Estados UnidosFil: Stokes, Karen Y.. State University of Louisiana; Estados UnidosFil: Carroll, Jennifer L.. State University of Louisiana; Estados UnidosFil: Dragoi, Ana-Maria. State University of Louisiana; Estados UnidosFil: Qin, Cheng Xue. Baker Heart And Diabetes Institute; AustraliaFil: Ritchie, Rebecca H.. Baker Heart And Diabetes Institute; AustraliaFil: Sun, Hai. University Hospital Muenster; AlemaniaFil: Cuellar-Saenz, Hugo H.. State University of Louisiana; Estados UnidosFil: Rubinstein Guichon, Mara Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentina. Columbia University; Estados UnidosFil: Han, Yiping W.. Columbia University; Estados UnidosFil: Orr, A. Wayne. University Hospital Muenster; AlemaniaFil: Perretti, Mauro. Queen Mary University Of London; Reino UnidoFil: Granger, D. Neil. State University of Louisiana; Estados UnidosFil: Gavins, Felicity N.E.. State University of Louisiana; Estados Unido