Measurement Of The Smaller Poisson's Ratios And Related Compliances For Wood

Few direct measurements have been made of strains in the longitudinal L direction of wood when uniaxial loading takes place in the radial, R, or tangential, T, directions because of the difficulty of making the small measurements involved. Improved accuracy in measurements of this type were achieved by using low modulus strain gages having little or no sensitivity perpendicular to the gage axis, by having low noise signals in connecting wires, by making strain measurements with a resolution of 107 inches per inch, and by having a proper loading device. Compliances from loadings made on different specimens representing a number of species were found to be correlated in that the strain in the L direction per unit of stress in the R or T direction was proportional to the strain per unit stress in the load direction (R or T). The best estimates that could be found for Poisson's ratios vTL and VRL were 0.030 and 0.043, respectively. For some reason basswood data from a single board did not seem to fit with the rest of the data

Human Leukocyte Antigen (HLA) Class I Molecule Components and Amyloid Precursor-Like Protein 2 (APLP2): Roles in Pancreatic Cancer Cell Migration

Human leukocyte antigen (HLA) class I molecules are composed of a light chain (beta 2-microglobulin (β2m)) and HLA heavy chain. The heavy chains of these molecules have three different isotypes (–A, -B, and –C) and are highly polymorphic with thousands of sequence variations termed allotypes. The best-known role for these molecules is within the immune system, however, recent research implicates components of this molecule can function outside of this known immune role by contributing to cell migration. However, no studies have been published thus far investigating this non-immune function in pancreatic cancer. Therefore, I examined the role of HLA class I molecule components in pancreatic cancer cell migration. My studies showed that when β2m was knocked down using β2m-specific siRNA, cell migration decreased in the S2-013 and PANC-1 cells but increased in the MIA PaCa-2 cells. Interactions with amyloid precursor-like protein 2 (APLP2) as well as total APLP2 protein expression are potential mediators of these effects. HLA-B knockdown using HLA-B-specific siRNA increased cell migration in S2-013 cells, while in both the PANC-1 and MIA PaCa-2 cells knockdown decreased migration. Alterations in integrin beta 1 (ITGB1) and focal adhesion kinase (FAK) are potential intermediates in HLA-B’s effects on cell migration. Furthermore, knockdown using allotype-specific siRNA of HLA-A24 in the S2-013 cell line and HLA-A2 in PANC-1 cell line increased migration while knockdown of HLA-A2 in the S2-013 cell line and HLA-A24 in the MIA PaCa-2 cell line reduced cell migration. Mechanistically, APLP2 C-terminal fragment (APLP2-CT) and epidermal growth factor receptor (EGFR) are likely mediators of this phenotype. Finally, the histone deacetylase (HDAC) inhibitor M344 and its effects on APLP2 processing in the S2-013 pancreatic cancer cell line was interrogated as previous studies indicated M344 treatment reduced levels of β-site APP cleaving enzyme 1 (BACE1), a proteolytic enzyme involved in APLP2 cleavage. M344 treatment of S2-013 cells led to a significant reduction in cell proliferation, migration, and APLP2-CT expression. Overall, this work sheds light on a novel role for the HLA class I molecules in pancreatic cancer outside of their known immune function and implicates M344 as a potential new therapeutic for this lethal disease

Measuring Shear Moduli in Wood with Small Tension and Compression Samples

Shear moduli in wood were measured on tension and compression specimens by means of rosettes of specially made bonded resistance strain gages. Angle α between the load axis and the longitudinal, L, direction for matched specimens were 10, 20, and 45 degrees. Better results were achieved with the tension specimens than with the compression specimens probably because of end restraint of the compression specimens. Although there were only small differences among shear moduli measured at angles α of 10, 20, and 45 degrees, the 20-degree specimens usually had shear moduli values that were closest to those from plate specimens. The maximum strain in each test specimen was not parallel to the load axis: for most specimens it was calculated by strain gage rosette analysis to be at an angle between 20 and 30 degrees to the load axis. Although instrumentation with strain gages is time-consuming, the specimens are easier to cut accurately from wood than are the plate specimens that are sometimes used

Elastic Constants for Hardwoods Measured from Plate and Tension Tests

Measurements of shear moduli GLR and GLT, Young's moduli EL, ER, and ET, and Poisson's ratios vLT and vLR were made at approximately 12% moisture content from material cut from 18 eastern hardwood logs. Shear moduli calculated from off-axis tension tests with angle of load to the L-axis of 20° were slightly larger than those from plate tests. ER values determined from off-axis tensile tests closely approximated those determined from tensile tests in the R direction. Poisson's ratios for basswood, cottonwood, and soft maple were negative (strains parallel and perpendicular to the load direction were both positive) in the LT plane for loadings at 20° to the L direction. Some significant correlations were found between the reciprocals of elastic constants and the reciprocals of density at test, also between the reciprocals of shear moduli and the reciprocals of Young's moduli ER and ET. There was less variability in measurements made in the LR plane than in the LT plane

Thin film piezoelectric resonating device Final report, 28 May 1965 - 28 Jul. 1966

Cadmium sulfide thin film, high frequency piezoelectric resonato

General Chemistry Students\u27 Perceived Self-Efficacy after Completing Project-Based Service-Learning Activities

A New England community college reported that 60% of General Chemistry college students, who were science, technology, engineering, and mathematics (STEM) majors, did not advance in the STEM curriculum. To potentially increase student persistence in STEM curriculum, this qualitative case study project explored the self-efficacy perceptions of General Chemistry students after participating in project-based service-learning with elementary-school students. Bandura\u27s social cognitive theory provided the conceptual framework for the study, supporting an understanding of learner self-efficacy. Research questions focused on chemistry students perceived self-efficacy after interactions with elementary-school students, teamwork, and the development of a project. Semistructured interviews with 10 participants and five reflective journals provided data that were coded and analyzed using the content analysis method. Findings revealed project-based service-learning was a viable strategy to enhance the perceived self-efficacy of college chemistry students. An increase in chemical knowledge, mentoring and teaching elementary-school students, and being part of a team developing and executing the project were frequently reported as sources for increased self-efficacy. Based on results, a 2-day professional development conference to train STEM faculty in project-based service-learning pedagogy was developed. This study affects positive social change by communicating the value of project-based service-learning in chemistry for increasing the self-efficacy of STEM majors and providing a model of professional development to improve student persistence

Wireless Tissue Palpation for Intraoperative Detection of Lumps in the Soft Tissue

In an open surgery, identification of precise margins for curative tissue resection is performed by manual palpation. This is not the case for minimally invasive and robotic procedures, where tactile feedback is either distorted or not available. In this paper, we introduce the concept of intraoperative wireless tissue palpation. The wireless palpation probe (WPP) is a cylindrical device (15 mm in diameter, 60 mm in length) that can be deployed through a trocar incision and directly controlled by the surgeon to create a volumetric stiffness distribution map of the region of interest. This map can then be used to guide the tissue resection to minimize healthy tissue loss. The wireless operation prevents the need for a dedicated port and reduces the chance of instrument clashing in the operating field. The WPP is able to measure in real time the indentation pressure with a sensitivity of 34 Pa, the indentation depth with an accuracy of 0.68 mm, and the probe position with a maximum error of 11.3 mm in a tridimensional workspace. The WPP was assessed on the benchtop in detecting the local stiffness of two different silicone tissue simulators (elastic modulus ranging from 45 to 220 kPa), showing a maximum relative error below 5%. Then, in vivo trials were aimed to identify an agar-gel lump injected into a porcine liver and to assess the device usability within the frame of a laparoscopic procedure. The stiffness map created intraoperatively by the WPP was compared with a map generated ex vivo by a standard uniaxial material tester, showing less than 8% local stiffness error at the site of the lump

Parameters for successful nonoperative management of traumatic aortic injury

ObjectiveBlunt traumatic aortic injury is associated with significant mortality, and increased computed tomography use identifies injuries not previously detected. This study sought to define parameters identifying patients who can benefit from medical management.MethodsWe reviewed 4.5 years of blunt traumatic aortic injuries. Injury was classified as grade I (intimal flap or intramural hematoma), II (small pseudoaneurysm <50% circumference), III (large pseudoaneurysm >50% circumference), and IV (rupture/transection). Secondary signs of injury included pseudocoarctation, extensive mediastinal hematoma, and large left hemothorax. Follow-up, including computed tomography, was reviewed.ResultsWe identified 97 patients: 31 grade I, 35 grade II, 24 grade III, and 7 grade IV; 67(69%) male; mean age 47 ± 18.8 years, mean Injury Severity Score 38.8 ± 14.6; overall survival 76 (78.4%). Secondary signs of injury were found in 30 patients. Overall, 52 (53.6%) underwent repair, 45 undergoing thoracic endovascular aortic repair, with 2 (2.22%) procedure-related deaths, and 7 undergoing open repair. Five patients undergoing thoracic endovascular aortic repair required 7 additional procedures. In 45 medically managed patients, there were 14 deaths (31%), all secondary to associated injuries. Injury Severity Scores of survivors and nonsurvivors were 33 ± 10.8 and 48.6 ± 12.8, respectively (P < .001). Follow-up showed resolution or no change in 21 (91%) and a small increase in 2 grade I injuries.ConclusionsAll blunt traumatic aortic injury does not necessitate repair. Stratification by injury grade and secondary signs of injury identifies patients appropriate for medical management. Grade IV injury necessitates emergency procedures and carries high mortality. Grade III injury with secondary signs of injury should be urgently repaired; patients without secondary signs of injury may undergo delayed repair. Grade I and II injuries are amenable to medical management

The Point Digit II: Mechanical Design and Testing of a Ratcheting Prosthetic Finger

Introduction People with partial hand loss represent the largest population of upper limb amputees by a factor of 10. The available prosthetic componentry for people with digit loss provide various methods of control, kinematic designs, and functional abilities. Here, the Point Digit II is empirically tested and a discussion is provided comparing the Point Digit II with the existing commercially available prosthetic fingers. Materials and Methods Benchtop mechanical tests were performed using prototype Point Digit II prosthetic fingers. The battery of tests included a static load test, a static mounting tear-out test, a dynamic load test, and a dynamic cycle test. These tests were implemented to study the mechanisms within the digit and the ability of the device to withstand heavy-duty use once out in the field. Results The Point Digit II met or exceeded all geometric and mechanical specifications. The device can withstand over 300 lbs of force applied to the distal phalange and was cycled over 250,000 times without an adverse event representing 3 years of use. Multiple prototypes were utilized across all tests to confirm the ability to reproduce the device in a reliable manner. Conclusions The Point Digit II presents novel and exciting features to help those with partial hand amputation return to work and regain ability. The use of additive manufacturing, unique mechanism design, and clinically relevant design features provides both the patient and clinician with a prosthetic digit, which improves upon the existing devices available. &nbsp;</p

'I-I' and 'I-me' : Transposing Buber's interpersonal attitudes to the intrapersonal plane

Hermans' polyphonic model of the self proposes that dialogical relationships can be established between multiple I-positions1 (e.g., Hermans, 2001a). There have been few attempts, however, to explicitly characterize the forms that these intrapersonal relationships may take. Drawing on Buber's (1958) distinction between the 'I-Thou' and 'I-It' attitude, it is proposed that intrapersonal relationships can take one of two forms: an 'I-I' form, in which one I-position encounters and confirms another I-position in its uniqueness and wholeness; and an 'I-Me' form, in which one I-position experiences another I-position in a detached and objectifying way. This article argues that this I-Me form of intrapersonal relating is associated with psychological distress, and that this is so for a number of reasons: Most notably, because an individual who objectifies and subjugates certain I-position cannot reconnect with more central I-positions when dominance reversal (Hermans, 2001a) takes place. On this basis, it is suggested that a key role of the therapeutic process is to help clients become more able to experience moments of I-I intrapersonal encounter, and it is argued that this requires the therapist to confirm the client both as a whole and in terms of each of his or her different voices