380 research outputs found

    Local sweating response to varying intradermal electrical stimulation patterns

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    The local sweat rate response (LSR) to intradermal electrical stimulation generates a sigmodal stimulus-response curve with a peak sweat rate generated by a 30 s period of continuous stimuli at a frequency of 8-16 Hz. The firing pattern of the sudomotor nerve driving sweat gland function in vivo, however, display a bursting firing pattern. Purpose: To compare the LSR to a 30 s continuous intradermal electrical stimulation frequency to a 30 s bursting pattern with a similar total number of stimuli. We hypothesize that there would be no difference in the LSR response between the two stimuli patterns. Methods: Subjects (n=5) were studied seated in a temperature-controlled room at 27°C. The LSR was measured with a miniature sweat capsule with guide sleeves for holding the intradermal stimulating electrodes. The air flow through the capsules was set at 100 ml/min. The water content of the effluent air was calculated by measuring the relative humidity (RH) and air temperature. The 10 continuous stimulus frequencies were 1, 2, 4, 6, 8, 10, 12, 16, 32, and 64 Hz. The bursting stimuli contained a similar total number of stimuli with a burst interval of ≈ 1.5 sec. The LSR was determined by the area under a 30 s sweat rate-time curve. RESULTS: The non-linear sigmoidal plots were significantly different (p = 0.0006) from each other with continuous stimuli resulting in a slightly greater peak response than the bursting pattern. CONCLUSION: These data do not support the hypothesis that a varied bursting pattern will improve sweat gland output during electrical activation of the sudomotor nerve

    Elevated central venous pressure: A consequence of exercise training-induced hypervolemia

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    Resting plasma volumes, and arterial and central venous pressures (CVP) were measured in 16 men before and after exercise training to determine if training-induced hypervolemia could be explained by a change in total vascular capacitance. In addition, resting levels of plasma vasopressin (AVP), atrial natriuretic peptide (ANP), aldosterone (ALD), and norepinephrine (NE) were measured before and after training. The same measurements of vacular volume, pressures, and plasma hormones were measured in 8 subjects who did not undergo exercise and acted as controls. The exercise training program consisted of 10 weeks of controlled cycle exercise for 30 min/d, 4 d/wk at 75 to 80 percent of maximal oxygen uptake (VO2max). A training effect was verified by a 20 percent increase in VO2max, a resting bradycardia, and a 370 ml (9 percent) increase in blood volume. Mean arterial blood pressure was unaltered by exercise training, but resting CVP increased. The percent change in blood volume from before to after training was linearly related to the percent change in CVP. As a consequence of elevations in both blood volume and CVP, the volume-to-pressure ratio was essentially unchanged following exercise training. Plasma AVP, ANP, ALD, and NE were unaltered. Results indicate that elevated CVP is a consequence of training-induced hypervolemia without alteration in total effective venous capacitance. This may represent a resetting of the pressure-volume stimulus-response relation for regulation of blood volume

    Analysis of Mitotic Microtubule-Associated Proteins Using Mass Spectrometry Identifies Astrin, a Spindle-Associated Protein

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    We purified microtubules from a mammalian mitotic extract and obtained an amino acid sequence from each microtubule-associated protein by using mass spectrometry. Most of these proteins are known spindle-associated components with essential functional roles in spindle organization. We generated antibodies against a protein identified in this collection and refer to it as astrin because of its association with astral microtubule arrays assembled in vitro. Astrin is approximately 134 kDa, and except for a large predicted coiled-coil domain in its C-terminal region it lacks any known functional motifs. Astrin associates with spindle microtubules as early as prophase where it concentrates at spindle poles. It localizes throughout the spindle in metaphase and anaphase and associates with midzone microtubules in anaphase and telophase. Astrin also localizes to kinetochores but only on those chromosomes that have congressed. Deletion analysis indicates that astrin\u27s primary spindle-targeting domain is at the C terminus, although a secondary domain in the N terminus can target some of the protein to spindle poles. Thus, we have generated a comprehensive list of major mitotic microtubule-associated proteins, among which is astrin, a nonmotor spindle protein

    Descriptive Analysis of the Role Incumbents, Institutions and Geographical Settings Involved in the Emerging Profession of Church Management

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    Educational Administratio

    Multiple Mechanisms Regulate NuMA Dynamics at Spindle Poles

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    The large coiled-coil protein NuMA plays an essential role in organizing microtubule minus ends at spindle poles in vertebrate cells. Here, we use both in vivo and in vitro methods to examine NuMA dynamics at mitotic spindle poles. Using fluorescence recovery after photobleaching, we show that an exogenously expressed green-fluorescent-protein/NuMA fusion undergoes continuous exchange between soluble and spindle-associated pools in living cells. These dynamics require cellular energy and display an average half-time for fluorescence recovery of approximately 3 minutes. To explore how NuMA dynamics at spindle poles is regulated, we exploited the association of NuMA with microtubule asters formed in mammalian mitotic extracts. Using a monoclonal antibody specific for human NuMA, we followed the fate of human NuMA associated with microtubule asters upon dilution with a hamster mitotic extract. Consistent with in vivo data, this assay shows that NuMA can be displaced from the core of pre-assembled asters into the soluble pool. The half-time of NuMA displacement from asters under these conditions is approximately 5 minutes. Using this assay, we show that protein kinase activity and the NuMA-binding protein LGN regulate the dynamic exchange of NuMA on microtubule asters. Thus, the dynamic properties of NuMA are regulated by multiple mechanisms including protein phosphorylation and binding to the LGN protein, and the rate of exchange between soluble and microtubule-associated pools suggests that NuMA associates with an insoluble matrix at spindle poles

    The Remote Observatories of the Southeastern Association for Research in Astronomy (SARA)

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    We describe the remote facilities operated by the Southeastern Association for Research in Astronomy (SARA) , a consortium of colleges and universities in the US partnered with Lowell Observatory, the Chilean National Telescope Allocation Committee, and the Instituto de Astrofísica de Canarias. SARA observatories comprise a 0.96 m telescope at Kitt Peak, Arizona; one of 0.6 m aperture on Cerro Tololo, Chile; and the 1 m Jacobus Kapteyn Telescope at the Roque de los Muchachos, La Palma, Spain. All are operated using standard VNC or Radmin protocols communicating with on-site PCs. Remote operation offers considerable flexibility in scheduling, allowing long-term observational cadences difficult to achieve with classical observing at remote facilities, as well as obvious travel savings. Multiple observers at different locations can share a telescope for training, educational use, or collaborative research programs. Each telescope has a CCD system for optical imaging, using thermoelectric cooling to avoid the need for frequent local service, and a second CCD for offset guiding. The Arizona and Chile telescopes also have fiber-fed echelle spectrographs. Switching between imaging and spectroscopy is very rapid, so a night can easily accommodate mixed observing modes. We present some sample observational programs. For the benefit of other groups organizing similar consortia, we describe the operating structure and principles of SARA, as well as some lessons learned from almost 20 years of remote operations

    Improved control strategies for the environment within cell culture bioreactors

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    This paper describes the development of improved control strategies for the standard environmental conditions in a fed-batch bioreactor used for monoclonal antibody cell culture. The consequences of relying on fixed parameter PID based controllers are considered and poor performance is demonstrated as a consequence of non-linearity and loop interactions. The benefits from adopting a more sophisticated control strategy are considered. Model Predictive Control (MPC) relies on a process model that can be identified from small system perturbations. It considers the predicted longer-term response and consequently can deliver improved control and satisfy user defined constraints. Results from experimental trials demonstrate the capability of MPC and the merits are discussed with regards to industrial application

    Interactions between water activity and temperature on the Aspergillus flavus transcriptome and aflatoxin B1 production

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    Effects of Aspergillus flavus colonization of maize kernels under different water activities (aw; 0.99 and 0.91) and temperatures (30, 37 °C) on (a) aflatoxin B1 (AFB1) production and (b) the transcriptome using RNAseq were examined. There was no significant difference (p = 0.05) in AFB1 production at 30 and 37 °C and 0.99 aw. However, there was a significant (p = 0.05) increase in AFB1 at 0.91 aw at 37 °C when compared with 30 °C/0.99 aw. Environmental stress effects using gene ontology enrichment analysis of the RNA-seq results for increasing temperature at 0.99 and 0.91 aw showed differential expression of 2224 and 481 genes, respectively. With decreasing water availability, 4307 were affected at 30 °C and 702 genes at 37 °C. Increasing temperature from 30 to 37 °C at both aw levels resulted in 12 biological processes being upregulated and 9 significantly downregulated. Decreasing aw at both temperatures resulted in 22 biological processes significantly upregulated and 25 downregulated. The interacting environmental factors influenced functioning of the secondary metabolite gene clusters for aflatoxins and cyclopiazonic acid (CPA). An elevated number of genes were co-regulated by both aw and temperature. An interaction effect for 4 of the 25 AFB1 genes, including regulatory and transcription activators occurred. For CPA, all 5 biosynthetic genes were affected by aw stress, regardless of temperature. The molecular regulation of A. flavus in maize is discussed

    Interactions between water activity and temperature on the Aspergillus flavus transcriptome and aflatoxin B1 production

    Get PDF
    Effects of Aspergillus flavus colonization of maize kernels under different water activities (aw; 0.99 and 0.91) and temperatures (30, 37 °C) on (a) aflatoxin B1 (AFB1) production and (b) the transcriptome using RNAseq were examined. There was no significant difference (p = 0.05) in AFB1 production at 30 and 37 °C and 0.99 aw. However, there was a significant (p = 0.05) increase in AFB1 at 0.91 aw at 37 °C when compared with 30 °C/0.99 aw. Environmental stress effects using gene ontology enrichment analysis of the RNA-seq results for increasing temperature at 0.99 and 0.91 aw showed differential expression of 2224 and 481 genes, respectively. With decreasing water availability, 4307 were affected at 30 °C and 702 genes at 37 °C. Increasing temperature from 30 to 37 °C at both aw levels resulted in 12 biological processes being upregulated and 9 significantly downregulated. Decreasing aw at both temperatures resulted in 22 biological processes significantly upregulated and 25 downregulated. The interacting environmental factors influenced functioning of the secondary metabolite gene clusters for aflatoxins and cyclopiazonic acid (CPA). An elevated number of genes were co-regulated by both aw and temperature. An interaction effect for 4 of the 25 AFB1 genes, including regulatory and transcription activators occurred. For CPA, all 5 biosynthetic genes were affected by aw stress, regardless of temperature. The molecular regulation of A. flavus in maize is discussed
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