Embryonic Lethality, Liver Degeneration, and Impaired NF-κB Activation in IKK-β-Deficient Mice

AbstractIκB kinase-α and -β (IKK-α and IKK-β), the catalytic subunits of the IKK complex, phosphorylate IκB proteins on specific serine residues, thus targeting IκB for degradation and activating the transcription factor NF-κB. To elucidate the in vivo function of IKK-β, we generated IKK-β-deficient mice. The homozygous mouse embryo dies at ∼14.5 days of gestation due to liver degeneration and apoptosis. IKK-β-deficient embryonic fibroblasts have both reduced basal NF-κB activity and impaired cytokine-induced NF-κB activation. Similarly, basal and cytokine-inducible kinase activities of the IKK complex are greatly reduced in IKK-β-deficient cells. These results indicate that IKK-β is crucial for liver development and regulation of NF-κB activity and that IKK-α can only partially compensate for the loss of IKK-β

The effect of arm training on thermoregulatory responses and calf volume during upper body exercise

The final publication is available at Springer via https://doi.org/10.1007/s00421-014-2842-9.PURPOSE: The smaller muscle mass of the upper body compared to the lower body may elicit a smaller thermoregulatory stimulus during exercise and thus produce novel training-induced thermoregulatory adaptations. Therefore, the principal aim of the study was to examine the effect of arm training on thermoregulatory responses during submaximal exercise. METHODS: Thirteen healthy male participants (Mean ± SD age 27.8 ± 5.0 years, body mass 74.8 ± 9.5 kg) took part in 8 weeks of arm crank ergometry training. Thermoregulatory and calf blood flow responses were measured during 30 min of arm cranking at 60% peak power (W peak) pre-, and post-training and post-training at the same absolute intensity as pre-training. Core temperature and skin temperatures were measured, along with heat flow at the calf, thigh, upper arm and chest. Calf blood flow using venous occlusion plethysmography was performed pre- and post-exercise and calf volume was determined during exercise. RESULTS: The upper body training reduced aural temperature (0.1 ± 0.3 °C) and heat storage (0.3 ± 0.2 J g(-1)) at a given power output as a result of increased whole body sweating and heat flow. Arm crank training produced a smaller change in calf volume post-training at the same absolute exercise intensity (-1.2 ± 0.8% compared to -2.2 ± 0.9% pre-training; P < 0.05) suggesting reduced leg vasoconstriction. CONCLUSION: Training improved the main markers of aerobic fitness. However, the results of this study suggest arm crank training additionally elicits physiological responses specific to the lower body which may aid thermoregulation.Peer reviewedFinal Accepted Versio

Increased energy expenditure in growing adolescents with Crohn's disease

Undernutrition is considered to have a central role in the pathogenesis of growth retardation in Crohn's disease. This may occur as a consequence of inadequate food intake, increased energy expenditure, or both. Ten growing adolescents with inactive Crohn's disease were assessed with respect to anthropometric parameters and resting energy expenditure, measured by indirect calorimetry during remission, repeated in relapse (N = 5), and compared to that predicted from the Harris-Benedict formula. Mean energy intake was assessed with seven-day diaries in five patients and compared to recommended intake for age, sex, weight, and physical activity. Ten healthy, growing, age- and sex-matched adolescents served as controls. Nine patients with inactive Crohn's disease, who had ceased growing, were matched for disease site and duration and acted as disease controls. Patients and disease controls had lower body mass index (19.2 ± 0.6; 20.9 ± 0.7) than healthy controls (23.7 ± 0.6; P < 0.001). Percent body fat was lower in patients (13.2 ± 1.9%) compared to healthy controls (20.5 ± 2.4%; P < 0.05) but not to disease controls (17.0 ± 2.6%). Patients had higher resting energy expenditure per kilogram of fat-free mass than disease or healthy controls (36.9 ± 5.1; 32.9 ± 2.6; 30.9 ± 2.1 kcal; P < 0.02). Measured resting energy expenditure in patients, but not in disease or healthy controls, was higher than the predicted (measured: predicted 1.15, 1.03, 0.9, respectively; P < 0.03). Energy intake in patients was 97% of recommended intake but the measured ratio of energy intake/resting energy expenditure was lower than the predicted ratio (1.49 vs 1.71; P < 0.05). During subsequent relapse in five patients resting energy expenditure was unchanged. In growing adolescents with inactive Crohn's disease, there is increased energy expenditure that is not accompanied by an increase in energy intake; Relapse of disease does not appear to increase resting energy expenditure further but may 'divert' energy from growth to disease activity. This suggests that nutritional therapy should be directed towards increasing caloric intake to maximize growth potential

<em>In situ</em> wavefront correction and its application to micromanipulation

In any optical system, distortions to a propagating wavefront reduce the spatial coherence of a light field, making it increasingly difficult to obtain the theoretical diffraction-limited spot size. Such aberrations are severely detrimental to optimal performance in imaging, nanosurgery, nanofabrication and micromanipulation, as well as other techniques within modern microscopy. We present a generic method based on complex modulation for true in situ wavefront correction that allows compensation of all aberrations along the entire optical train. The power of the method is demonstrated for the field of micromanipulation, which is very sensitive to wavefront distortions. We present direct trapping with optimally focused laser light carrying power of a fraction of a milliwatt as well as the first trapping through highly turbid and diffusive media. This opens up new perspectives for optical micromanipulation in colloidal and biological physics and may be useful for various forms of advanced imaging.</p

‘Lives of living death’: The reproductive lives of slave women in the cane world of Louisiana

This paper examines the seasonality of childbirth among slave women and addresses the relationship between seasonal workloads, nutrition, and pregnancy on large sugar plantations in nineteenth-century Louisiana. Unlike the rest of the American South, where the slave population grew, bondspeople in southern Louisiana experienced natural population decrease. This derived in part from imbalanced sex ratios, but as this article shows, conceptions peaked during the annual harvest season but fell away at other times due to nutritional stress, overwork, heat, and exhaustion. By combining plantation sources with contemporary scholarship on reproductive physiology, the article places Louisiana's reproductive history in contest and establishes the limits sugar production imposed on the slave women's capacity for childbirth