Creatine Kinase, Lactate Dehydrogenase, and Myoglobin Responses Following Repeated Wingate Anaerobic Tests Versus Barbell Back Squats: a Pilot Study

The results from many previous studies have demonstrated that muscle damage and delayed onset muscle soreness are due primarily to high force, eccentric muscle actions. However, the majority of investigators have examined these responses following single-joint, isokinetic assessments. The purpose of this study was to examine creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin responses following repeated Wingate anaerobic tests versus multiple sets of the barbell back squat exercise. Six recreationally resistance-trained men (mean ± SD age = 23 ± 2 years, body mass = 88.0 ± 17.8 kg, one repetition-maximum [1RM] back squat = 150.0 ± 28.3 kg) volunteered for this investigation, and visited the laboratory on five separate occasions. For the back squat protocol, the subjects performed six sets until volitional exhaustion using 75% of the 1RM with two minutes of rest between each set. For all repetitions, the subjects squatted to the parallel position. For the Wingate protocol, the subjects performed three tests with a 10 minute recovery period between each attempt. The order of these two protocols was randomized, and all testing for the study occurred at the same time of day. The subjects were required to refrain from vigorous physical activity during the study. Immediately prior to and 24 hours following each protocol, the subjects provided a venous blood sample from a superficial forearm vein. At the conclusion of the study, all samples were processed for CK, LDH, and myoglobin analyses. Three separate two-way (time [Pre versus Post] × protocol [squats versus Wingate anaerobic tests]) repeated measures analyses of variance were used to examine the CK, LDH, and myoglobin data. For CK, there was a significant time × protocol interaction (partial eta squared = .761). Follow-up paired samples t-tests indicated that the mean CK values increased following the squat protocol (Pre mean ± SD = 233.2 ± 97.4; Post = 457.0 ± 119.9 IU/L), but not the Wingate anaerobic tests (Pre = 218.5 ± 103.9; Post = 231.7 ± 65.3 IU/L). There was no mean difference between the protocols for both LDH and myoglobin. The primary finding from this pilot study was that performing six sets of barbell back squats using 75% of the 1RM significantly increased blood CK levels in resistance-trained men. Although additional studies with larger sample sizes are needed to confirm our findings, CK appears to be a more sensitive measure of muscle damage than both LDH and myoglobin

Bostonia: The Boston University Alumni Magazine. Volume 20

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Epoxy Composites Using Wood Pulp Components as Fillers

The components of wood, especially lignin and cellulose, have great potential for improving the properties of polymer composites. In this chapter, we discuss some of the latest developments from our lab on incorporating wood-based materials into epoxy composites. Lignosulfonate was used as a flame retardant and cellulose nanocrystals were used as reinforcing materials. Lignosulfonate will disperse well in epoxy, but phase separates during curing. An epoxidation reaction was developed to immobilize the lignosulfonate during curing. The lignosulfonate–epoxy composites were characterized using microcombustion and cone calorimetry tests. Cellulose also has poor interfacial adhesion to hydrophobic polymer matrices. Cellulose fibers and nanocrystals aggregate when placed in epoxy resin, resulting in very poor dispersion. The cellulose nanocrystal surface was modified with phenyl containing materials to disrupt cellulose interchain hydrogen bonding and improve dispersion in the epoxy resin. The cellulose nanocrystal – epoxy composites were characterized for mechanical strength using tensile tests, water barrier properties using standardized water absorption, glass transition temperatures using differential calorimetry, and aggregation and dispersion using microscopic techniques

The impact of General Dental Council registration and continuing professional development on UK dental care professionals:(1) dental nurses.

Objective To investigate the impact of GDC registration and mandatory CPD on dental nurses’ views, job satisfaction and intention to leave. Design Postal/online survey, conducted in parallel with a survey of dental technicians. Setting UK private and NHS practices, community services, dental hospitals. Subjects and methods Representative sample of General Dental Council registrants. Main outcome measures Job satisfaction; intention to leave profession (dependent variable in regression analysis). Results Eleven were ineligible (left profession, moved abroad); 267 (44% of those eligible) responded, all female. Respondents’ mean age was 38.2 years (sd 10.74). The general principle of registration was endorsed by 67%, and compulsory registration by 51%, but the fee level by only 6%. Most nurses did not feel that registration had affected their view of dental nursing as a career (56%), their role (74%) or status (86%) within the dental team, or that CPD helped them to do their job better (76%). Fiftly-six percent were not satisfied with their job, and 22% intended to leave the profession. Intention to leave was predicted by younger age and greater dissatisfaction with physical working conditions and opportunities to progress. Conclusions Widely held criticisms regarding the costs and relevance of registration and CPD coupled with a potentially high level of attrition from the profession suggest a review of the fee and salary structure and greater financial support for CPD is warranted

Negatively Charged Excitons and Photoluminescence in Asymmetric Quantum Well

We study photoluminescence (PL) of charged excitons ($X^-$) in narrow asymmetric quantum wells in high magnetic fields B. The binding of all $X^-$ states strongly depends on the separation $\delta$ of electron and hole layers. The most sensitive is the ``bright'' singlet, whose binding energy decreases quickly with increasing $\delta$ even at relatively small B. As a result, the value of B at which the singlet--triplet crossing occurs in the $X^-$ spectrum also depends on $\delta$ and decreases from 35 T in a symmetric 10 nm GaAs well to 16 T for $\delta=0.5$ nm. Since the critical values of $\delta$ at which different $X^-$ states unbind are surprisingly small compared to the well width, the observation of strongly bound $X^-$ states in an experimental PL spectrum implies virtually no layer displacement in the sample. This casts doubt on the interpretation of PL spectra of heterojunctions in terms of $X^-$ recombination

Piezoelectric Carbon Nanotube Tape for Use in Sensor Technology

No abstract availabl

Berkeley Supernova Ia Program I: Observations, Data Reduction, and Spectroscopic Sample of 582 Low-Redshift Type Ia Supernovae

In this first paper in a series we present 1298 low-redshift (z\leq0.2) optical spectra of 582 Type Ia supernovae (SNe Ia) observed from 1989 through 2008 as part of the Berkeley SN Ia Program (BSNIP). 584 spectra of 199 SNe Ia have well-calibrated light curves with measured distance moduli, and many of the spectra have been corrected for host-galaxy contamination. Most of the data were obtained using the Kast double spectrograph mounted on the Shane 3 m telescope at Lick Observatory and have a typical wavelength range of 3300-10,400 Ang., roughly twice as wide as spectra from most previously published datasets. We present our observing and reduction procedures, and we describe the resulting SN Database (SNDB), which will be an online, public, searchable database containing all of our fully reduced spectra and companion photometry. In addition, we discuss our spectral classification scheme (using the SuperNova IDentification code, SNID; Blondin & Tonry 2007), utilising our newly constructed set of SNID spectral templates. These templates allow us to accurately classify our entire dataset, and by doing so we are able to reclassify a handful of objects as bona fide SNe Ia and a few other objects as members of some of the peculiar SN Ia subtypes. In fact, our dataset includes spectra of nearly 90 spectroscopically peculiar SNe Ia. We also present spectroscopic host-galaxy redshifts of some SNe Ia where these values were previously unknown. [Abridged]Comment: 34 pages, 11 figures, 11 tables, revised version, re-submitted to MNRAS. Spectra will be released in January 2013. The SN Database homepage (http://hercules.berkeley.edu/database/index_public.html) contains the full tables, plots of all spectra, and our new SNID template