2,937 research outputs found
Microbial fuel cell technology for measurement of microbial respiration of lactate as an example of bioremediation amendment
Microbial fuel cell (MFC) based sensing was explored to provide for the development of an insitu bioremediation monitoring approach for substrate concentrations and microbial respiration rates. MFC systems were examined in column systems where Shewanella oneidensis MR1 used an external electron acceptor (an electrode) to metabolize lactate (a bioremediation additive) to acetate. Column systems were operated with varying influent lactate concentrations (0-41mM) and monitored for current generation (0.01-0.39mA). Biological current generation paralleled bulk phase lactate concentration both in the influent and in the bulk phase at the anode; current values were correlated to lactate concentration at the anode (R 2=0.9), The electrical signal provided real-time information for electron donor availability and biological activity. These results have practical implications for efficient and inexpensive real-time monitoring of insitu bioremediation processes where information on substrate concentrations is often difficult to obtain and where information on the rate and nature of metabolic processes is neede
Differential Response To Tabata Interval Versus Traditional Kettlebell Training Protocol
Please view abstract in the attached PDF file
Cardiovascular and metabolic demands of the kettlebell swing using a Tabata interval versus a traditional resistance protocol
International Journal of Exercise Science 7(3) : 179-185, 2014. Tabata (TAB) training, consisting of eight cycles of 20 seconds of maximal exercise followed by 10 seconds of rest, is time-efficient, with aerobic and anaerobic benefit. This study investigated the cardiovascular and metabolic demands of a TAB versus traditional (TRAD) resistance protocol with the kettlebell swing. Fourteen young (18-25y), non-obese (BMI 25.7±0.8 kg/m2) participants reported on three occasions. All testing incorporated measurements of HR, oxygen consumption, and blood lactate accumulation. Each participant completed Tabata kettlebell swings (male- 8kg, female- 4.5kg; 8 intervals; 20s maximal repetitions, 10s rest). On a subsequent visit (TRAD), the total swings from the TAB protocol were evenly divided into 4 sets, with 90s rest between sets. Outcome measures were compared using paired t-tests. The TAB was completed more quickly than the TRAD protocol (240.0±0.0 v. 521.5±3.3 sec, P\u3c0.01), at a higher perceived exertion (Borg RPE; 15.1±0.7 v. 11.7±0.9, P\u3c0.01). The TAB elicited a higher average VO2 value (33.1±1.5 v. 27.2±1.6 ml/kg/min, P\u3c0.01), percent of VO2peak achieved (71.0±0.3 v. 58.4±0.3%, P\u3c0.01), maximal HR (162.4±4.6 v. 145.6±4.8 bpm, P\u3c0.01), and post-exercise blood lactate concentration (6.4±1.1 v. 3.7±0.5 mmol/L, P\u3c0.01). Conclusion: The kettlebell swing demonstrated significantly greater cardiovascular and metabolic responses within a TAB vs. TRAD framework. Appropriate screening and risk stratification are advised before implementing kettlebell swings
Direct simulation of ion beam induced stressing and amorphization of silicon
Using molecular dynamics (MD) simulation, we investigate the mechanical
response of silicon to high dose ion-irradiation. We employ a realistic and
efficient model to directly simulate ion beam induced amorphization. Structural
properties of the amorphized sample are compared with experimental data and
results of other simulation studies. We find the behavior of the irradiated
material is related to the rate at which it can relax. Depending upon the
ability to deform, we observe either the generation of a high compressive
stress and subsequent expansion of the material, or generation of tensile
stress and densification. We note that statistical material properties, such as
radial distribution functions are not sufficient to differentiate between
different densities of amorphous samples. For any reasonable deformation rate,
we observe an expansion of the target upon amorphization in agreement with
experimental observations. This is in contrast to simulations of quenching
which usually result in denser structures relative to crystalline Si. We
conclude that although there is substantial agreement between experimental
measurements and most simulation results, the amorphous structures being
investigated may have fundamental differences; the difference in density can be
attributed to local defects within the amorphous network. Finally we show that
annealing simulations of our amorphized samples can lead to a reduction of high
energy local defects without a large scale rearrangement of the amorphous
network. This supports the proposal that defects in amorphous silicon are
analogous to those in crystalline silicon.Comment: 13 pages, 12 figure
Protective Effects of the Launch/Entry Suit (LES) and the Liquid Cooling Garment(LCG) During Re-entry and Landing After Spaceflight
Heart rate and arterial pressure were measured during shuttle re-entry, landing and initial standing in crewmembers with and without inflated anti-g suits and with and without liquid cooling garments (LCG). Preflight, three measurements were obtained seated, then standing. Prior to and during re-entry, arterial pressure and heart rate were measured every five minutes until wheels stop (WS). Then crewmembers initiated three seated and three standing measurements. In subjects without inflated anti-g suits, SBP and DBP were significantly lower during preflight standing (P = 0.006; P = 0.001 respectively) and at touchdown (TD) (P = 0.001; P = 0.003 respectively); standing SBP was significantly lower after WS. on-LeG users developed significantly higher heart rates during re-entry (P = 0.029, maxG; P = 0.05, TD; P = 0.02, post-WS seated; P = 0.01, post-WS standing) than LCG users. Our data suggest that the anti-g suit is effective, but the combined anti-g suit with LCG is more effective
Teenage acne and cancer risk in U.S. women: A prospective cohort study
BACKGROUND:
Acne reflects hormone imbalance and is a key component of several systemic diseases. We hypothesized that diagnosis of acne as a teenager might predict subsequent risk of hormone-related cancers.
METHODS:
We followed 99,128 female nurses in the Nurses' Health Study II cohort for 20 years (1989-2009) and used Cox proportional hazards models to estimate the hazard ratios (HRs) of 8 specific cancers (breast, thyroid, colorectal, ovarian, cervical, and endometrial cancers, melanoma, and non-Hodgkin lymphoma) for women with a history of severe teenage acne.
RESULTS:
After thoroughly adjusting for the previously known risk factors for each cancer, we found that among women with a history of severe teenage acne, the relative risk increased, with a multivariable-adjusted HR of 1.44 (95% confidence interval [CI], 1.03-2.01) for melanoma. We replicated this association in an independent melanoma case-control study of 930 cases and 1026 controls (multivariable-adjusted odds ratio, 1.27; 95% CI, 1.03-1.56). We also found that in both studies the individuals with teenage acne were more likely to have moles (52.7% vs 50.1%, P < .001 in the cohort study; and 55.2% vs 45.1%, P = .004 in the case-control study).
CONCLUSIONS:
Our findings suggest that a history of teenage acne might be a novel risk factor for melanoma independent from the known factors, which supports a need for continued investigation of these relationships
Overexpression of Mcl-1 exacerbates lymphocyte accumulation and autoimmune kidney disease in lpr mice
Cell death by apoptosis has a critical role during embryonic development and in maintaining tissue homeostasis. In mammals,
there are two converging apoptosis pathways: the ‘extrinsic’ pathway, which is triggered by engagement of cell surface ‘death
receptors’ such as Fas/APO-1; and the ‘intrinsic’ pathway, which is triggered by diverse cellular stresses, and is regulated by prosurvival
and pro-apoptotic members of the Bcl-2 family of proteins. Pro-survival Mcl-1, which can block activation of the proapoptotic
proteins, Bax and Bak, appears critical for the survival and maintenance of multiple haemopoietic cell types. To
investigate the impact on haemopoiesis of simultaneously inhibiting both apoptosis pathways, we introduced the vavP-Mcl-1
transgene, which causes overexpression of Mcl-1 protein in all haemopoietic lineages, into Faslpr/lpr mice, which lack functional
Fas and are prone to autoimmunity. The combined mutations had a modest impact on myelopoiesis, primarily an increase in the
macrophage/monocyte population in Mcl-1tg/lpr mice compared with lpr or Mcl-1tg mice. The impact on lymphopoiesis was
striking, with a marked elevation in all major lymphoid subsets, including the non-conventional double-negative (DN) T cells
(TCRβ+
CD4–
CD8–
B220+
) characteristic of Faslpr/lpr mice. Of note, the onset of autoimmunity was markedly accelerated in Mcl-1tg/lpr
mice compared with lpr mice, and this was preceded by an increase in immunoglobulin (Ig)-producing cells and circulating
autoantibodies. This degree of impact was surprising, given the relatively mild phenotype conferred by the vavP-Mcl-1 transgene
by itself: a two- to threefold elevation of peripheral B and T cells, no significant increase in the non-conventional DN T-cell
population and no autoimmune disease. Comparison of the phenotype with that of other susceptible mice suggests that the
development of autoimmune disease in Mcl-1tg/lpr mice may be influenced not only by Ig-producing cells but also other
haemopoietic cell types
Recommended from our members
Airborne measurements of western U.S. wildfire emissions: Comparison with prescribed burning and air quality implications
Wildfires emit significant amounts of pollutants that degrade air quality. Plumes from three wildfires in the western U.S. were measured from aircraft during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) and the Biomass Burning Observation Project (BBOP), both in summer 2013. This study reports an extensive set of emission factors (EFs) for over 80 gases and 5 components of submicron particulate matter (PM1) from these temperate wildfires. These include rarely, or never before, measured oxygenated volatile organic compounds and multifunctional organic nitrates. The observed EFs are compared with previous measurements of temperate wildfires, boreal forest fires, and temperate prescribed fires. The wildfires emitted high amounts of PM1 (with organic aerosol (OA) dominating the mass) with an average EF that is more than 2 times the EFs for prescribed fires. The measured EFs were used to estimate the annual wildfire emissions of carbon monoxide, nitrogen oxides, total nonmethane organic compounds, and PM1 from 11 western U.S. states. The estimated gas emissions are generally comparable with the 2011 National Emissions Inventory (NEI). However, our PM1 emission estimate (1530 ± 570 Gg yr-1) is over 3 times that of the NEI PM2.5 estimate and is also higher thanthe PM2.5 emitted from all other sources in these states in the NEI. This study indicates that the source of OA from biomass burning in the western states is significantly underestimated. In addition, our results indicate that prescribed burning may be an effective method to reduce fine particle emissions
Incidental finding of a giant intracardiac angioma infiltrating both ventricles in a 35-year-old woman: a case report
Background: Primary cardiac tumors are rare and often asymptomatic or present with unspecific symptoms. Benign cardiac tumors of vascular origin are especially rare, with only few existing data in the literature. Case presentation: A 35-year-old Caucasian female patient presented to our department with an asymptomatic giant intracardiac angioma infiltrating both ventricles. Evaluation of this tumor involved electrocardiography, echocardiography, cardiac magnetic resonance imaging, coronary angiography, an open myocardial biopsy, and histological examination of the resected specimen. Because our patient was asymptomatic, she was managed conservatively with regular follow-up. We discuss the treatment options available in comparison with similar cases. Conclusion: Diagnosis and therapy of benign cardiac tumors, especially of asymptomatic lesions, can be a challenge. There is no evidence available to help in the management of such patients. An extensive evaluation is needed with different imaging modalities, and case-specific decisions should be made that involve experts in cardiology, cardio-oncology, and heart surgery
- …
