A High-Precision Micropipette Sensor for Cellular-Level Real-Time Thermal Characterization

We report herein development of a novel glass micropipette thermal sensor fabricated in a cost-effective manner, which is capable of measuring steady thermal fluctuation at spatial resolution of similar to 2 mu m with an accuracy of +/- 0.01 degrees C. We produced and tested various micrometer-sized sensors, ranging from 2 mu m to 30 mu m. The sensor comprises unleaded low-melting-point solder alloy (Sn-based) as a core metal inside a pulled borosilicate glass pipette and a thin film of nickel coating outside, creating a thermocouple junction at the tip. The sensor was calibrated using a thermally insulated calibration chamber, the temperature of which can be controlled with an accuracy of +/- 0.01 degrees C, and the thermoelectric power (Seebeck coefficient) of the sensor was recorded from 8.46 to 8.86 mu V/degrees C. We have demonstrated the capability of measuring temperatures at a cellular level by inserting our temperature sensor into the membrane of a live retinal pigment epithelium cell subjected to a laser beam with a focal spot of 6 mu m. We measured transient temperature profiles and the maximum temperatures were in the range of 38-55 +/- 0.5 degrees C.open111212sciescopu

UBR2 of the N-end rule pathway is required for chromosome stability via histone ubiquitylation in spermatocytes and somatic cells

The N-end rule pathway is a proteolytic system in which its recognition components (N-recognins) recognize destabilizing N-terminal residues of short-lived proteins as an essential element of specific degrons, called N-degrons. The RING E3 ligases UBR2 and UBR1 are major N-recognins that share size (200 kDa), conserved domains and substrate specificities to N-degrons. Despite the known function of the N-end rule pathway in degradation of cytosolic proteins, the major phenotype of UBR2-deficient male mice is infertility caused by arrest of spermatocytes at meiotic prophase I. UBR2-deficient spermatocytes are impaired in transcriptional silencing of sex chromosome-linked genes and ubiquitylation of histone H2A. In this study we show that the recruitment of UBR2 to meiotic chromosomes spatiotemporally correlates to the induction of chromatin-associated ubiquitylation, which is significantly impaired in UBR2-deficient spermatocytes. UBR2 functions as a scaffold E3 that promotes HR6B/UbcH2-dependent ubiquitylation of H2A and H2B but not H3 and H4, through a mechanism distinct from typical polyubiquitylation. The E3 activity of UBR2 in histone ubiquitylation is allosterically activated by dipeptides bearing destabilizing N-terminal residues. Insufficient monoubiquitylation and polyubiquitylation on UBR2-deficient meiotic chromosomes correlate to defects in double strand break (DSB) repair and other meiotic processes, resulting in pachytene arrest at stage IV and apoptosis. Some of these functions of UBR2 are observed in somatic cells, in which UBR2 is a chromatin-binding protein involved in chromatin-associated ubiquitylation upon DNA damage. UBR2-deficient somatic cells show an array of chromosomal abnormalities, including hyperproliferation, chromosome instability, and hypersensitivity to DNA damage-inducing reagents. UBR2-deficient mice enriched in C57 background die upon birth with defects in lung expansion and neural development. Thus, UBR2, known as the recognition component of a major cellular proteolytic system, is associated with chromatin and controls chromatin dynamics and gene expression in both germ cells and somatic cells. © 2012 Kwon et al

Workplace status differences and proactive behaviours:The role of perceived insider status and promotion criterion

Status difference is prevalent within working groups, profoundly influencing employees' perceptions and behaviours towards coworkers and their groups. Despite this ubiquity, exploring the effects of status difference within groups remains relatively underexamined. Drawing on social identity theory, this study examined how and when horizontal status difference (i.e., status comparison between a focal employee and his/her peers) and vertical status difference (i.e., status comparison between a focal employee and his/her leader) influence employees' perceived insider status and proactive behaviour. Results from 421 employees across 113 working groups indicated that horizontal status difference was positively related to perceived insider status, but vertical status difference had a curvilinear effect on perceived insider status. Furthermore, perceived insider status significantly mediated the impact of horizontal and vertical status differences on proactive behaviour. We also demonstrated that promotion criteria significantly moderated the relationship between horizontal status difference and perceived insider status; in particular, this relationship was stronger when organizations used a relative rather than an absolute promotion criterion

Harmonising nursing terminologies using a conceptual framework

The International Classification for Nursing Practice (ICNP®) and the Clinical Care Classification (CCC) System are standardised nursing terminologies that identify discrete elements of nursing practice, including nursing diagnoses, interventions, and outcomes. While CCC uses a conceptual framework or model with 21 Care Components to classify these elements, ICNP, built on a formal Web Ontology Language (OWL) description logic foundation, uses a logical hierarchical framework that is useful for computing and maintenance of ICNP. Since the logical framework of ICNP may not always align with the needs of nursing practice, an informal framework may be a more useful organisational tool to represent nursing content. The purpose of this study was to classify ICNP nursing diagnoses using the 21 Care Components of the CCC as a conceptual framework to facilitate usability and inter-operability of nursing diagnoses in electronic health records. Findings resulted in all 521 ICNP diagnoses being assigned to one of the 21 CCC Care Components. Further research is needed to validate the resulting product of this study with practitioners and develop recommendations for improvement of both terminologie

A paradox theory lens on proactivity, individual ambidexterity, and creativity:An empirical look

Paradox theory suggests that contradictory demands, like applying current work methods while exploring new ones, should be viewed as dualities with competing and complementary aspects. It advocates for employee ambidexterity, where employees must manage exploitation and exploration. We know little about how personal dispositions affect ambidexterity independently or when interacting with situational factors. Based on a time-lagged survey of 364 employee–supervisor pairs from 74 R&D teams, we found that proactive disposition was positively related to ambidexterity, enhancing creativity. Guided by trait activation theory, we found further that paradoxical supervision and job autonomy enhanced the relationship between proactive disposition and employee ambidexterity and the indirect effect of proactive disposition on creativity via ambidexterity. We discuss these findings' theoretical and practical implications, extending the literature on proactivity, ambidexterity, and paradox theory

Biomechanics Differ for Individuals With Similar Self-Reported Characteristics of Patellofemoral Pain During a High-Demand Multiplanar Movement Task

Context: Patellofemoral pain (PFP) is often categorized by researchers and clinicians using subjective self-reported PFP characteristics; however, this practice might mask important differences in movement biomechanics between PFP patients. Objective: To determine whether biomechanical differences exist during a high-demand multiplanar movement task for PFP patients with similar self-reported PFP characteristics but different quadriceps activation levels. Design: Cross-sectional design. Setting: Biomechanics laboratory. Participants: A total of 15 quadriceps deficient and 15 quadriceps functional (QF) PFP patients with similar self-reported PFP characteristics. Intervention: In total, 5 trials of a high-demand multiplanar land, cut, and jump movement task were performed. Main Outcome Measures: Biomechanics were compared at each percentile of the ground contact phase of the movement task (alpha =.05) between the quadriceps deficient and QF groups. Biomechanical variables included (1) whole-body center of mass, trunk, hip, knee, and ankle kinematics; (2) hip, knee, and ankle kinetics; and (3) ground reaction forces. Results: The QF patients exhibited increased ground reaction force, joint torque, and movement, relative to the quadriceps deficient patients. The QF patients exhibited: (1) up to 90, 60, and 35Nmore vertical, posterior, and medial ground reaction force at various times of the ground contact phase; (2) up to 4 degrees more knee flexion during ground contact and up to 4 degrees more plantarflexion and hip extension during the latter parts of ground contact; and (3) up to 26, 21, and 48 N.m more plantarflexion, knee extension, and hip extension torque, respectively, at various times of ground contact. Conclusions: PFP patients with similar self-reported PFP characteristics exhibit different movement biomechanics, and these differences depend upon quadriceps activation levels. These differences are important because movement biomechanics affect injury risk and athletic performance. In addition, these biomechanical differences indicate that different therapeutic interventions may be needed for PFP patients with similar self-reported PFP characteristics

Effect of amorphous Si quantum-dot size on 1.54 μm luminescence of Er

The role of the size of amorphous silicon quantum dots in the Er luminescence at 1.54 μm was investigated. As the dot size was increased, more Er ions were located near one dot due to its large surface area and more Er ions interacted with other ones. This Er-Er interaction caused a weak photoluminescence intensity, despite the increase in the effective excitation cross section. The critical dot size needed to take advantage of the positive effect on Er luminescence is considered to be about 2.0 nm, below which a small dot is very effective in the efficient luminescence of Er. © 2005 The Electrochemical Society. All rights reserved

Characterization of the Major Ions of Coal Creek Near Cedar City, Utah

The major ions of Coal Creek near Cedar City, in southwest Utah, were measured to determine if there were any differences in ion concentrations in July of 2014 as compared with spring measurements of 2012 and 2013. Past analyses have shown higher ion concentrations in lower regions of Coal Creek despite the apparent lack of water input. This research is aimed to better characterize these abrupt increases in concentration and determine if these trends varied when samples were acquired in the summer vs. in the spring when sample acquisition has occurred in the past. Environmental water samples were collected at evenly spaced locations in Coal Creek from State Route 14 Mile Marker 7 westward to where the creek intersects with Main Street in Cedar City. Ion concentrations were determined in water samples collected every other day for 3 consecutive weeks using Ion Chromatography (IC) and Atomic Absorption Spectroscopy (AA). The spatially intensive sampling revealed two previously unknown low volume springs that are highly concentrated in the major ions and discharge into the creek. Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to characterize trace metal concentrations within the water tributaries, in addition to IC to determine bulk anion content in the creek. The high ion concentrations of springs correlated well with known geologic features near the creek, such as faulted gypsum layers creating springs as well as evaporate deposits, both of which explain the doubling of ion concentrations seen in the examined section of Coal Creek