Offspring sex ratio in the Common Tern Sterna hirundo, a species with negligible sexual size dimorphism

In many vertebrates, male offspring are affected more than female offspring by adverse conditions during growth, resulting in facultative adjustment of offspring sex ratio by parents in response to social and environmental conditions during breeding. The greater vulnerability of male offspring is generally attributed to their higher energy requirements associated with their larger size, although greater sensitivity to adverse conditions could be related to other factors such as negative effects of androgens on male physiology. To control for sexual differences in body size, we examined variation in offspring sex ratio in the Common Tern Sterna hirundo , a species with negligible sexual size dimorphism. In this species, the last-laid egg (termed the c-egg) is smaller than the first two and hatches last, so that the chick obtains relatively little food and hence has a low probability of survival to fledging. This species thus provides a powerful model for examining sex-linked mortality and sex ratio variation under natural conditions. We found that the sex ratio of c-eggs, but not of earlier laid eggs, was significantly biased in favour of females. Chicks hatched from c-eggs (termed c-chicks) had low survival but female c-chicks had significantly higher survival than male c-chicks. These data provide strong evidence that factors other than sexual size dimorphism are responsible for producing greater vulnerability of male offspring to adverse conditions during growth.     

In Vivo Evaluation of Safety and Toxicity of a Lactobacillus jensenii Producing Modified Cyanovirin-N in a Rhesus Macaque Vaginal Challenge Model

Sexual transmission of human immunodeficiency virus type 1 (HIV-1) across the cervicovaginal mucosa in women is influenced by many factors including the microbiota and the presence of underlying inflammation. It is important that potential HIV preventative agents do not alter the mucosal environment in a way that enhances HIV acquisition. We examined the impact of a “live” microbicide on the vaginal mucosal environment in a rhesus macaque repeated vaginal simian-HIV (SHIV_SF162P3) challenge model. The microbicide contained a human vaginal Lactobacillus jensenii expressing the HIV-1 entry inhibitor, modified Cyanovirin-N (mCV-N), and henceforth called LB-mCV-N. Macaques were colonized vaginally each week with LB-mCV-N and sampled six days after colonization for culturable bacteria, pH and cervical-vaginal cytokines during the duration of the six-week study. We show that macaques that retained the engineered LB-mCV-N strain in their vaginal microbiota, during SHIV challenge, had lower pH, when colonization levels were higher, and had no evidence of inflammatory cytokines. Indeed, Interleukin-13, a mediator of inflammation, was detected less often in LB-mCV-N colonized macaques than in controls and we found higher levels of Interleukin 1 receptor antagonist (IL-1RA) in LB-mCV-N colonized macaques during the SHIV challenge period. We noted an inverse correlation between levels of mucosal IL-1RA and peak plasma viral load, thus higher IL-1RA correlated with lower viral load in LB-mCV-N treated macaques. These data support the use of LB-mCV-N as a safe “live” microbicide and suggest that lactobacilli themselves may positively impact the mucosal environment.     

Effects of unsteady state conditions on the biooxidation of methyl ethyl and methyl isobutyl ketone in continuous flow liquid phase cultures

The effects of changing operating conditions on the biooxidation of methyl ethyl and/or methyl isobutyl ketone in continuous flow enrichment culture are examined. Particular emphasis is placed on responses to step changes in feed stream concentrations and to substrate pulses injected directly into the culture supernatant. In general, the enrichment culture was better able to handle transients involving methyl isobutyl ketone, the preferred carbon substrate. However, the highly complex response patterns observed clearly indicated major gaps in knowledge concerning the physiology of methyl ketone-oxidizing bacteria. In spite of the two carbon substrates investigated being major environmental pollutants, their removal in waste biotreatment processes is remarkably little understood.     

Respiratory Sinus Arrhythmia Versus Neck/Trapezius EMG and Incentive Inspirometry Biofeedback for Asthma: A Pilot Study

This pilot study compared biofeedback to increase respiratory sinus arrhythmia (RSA) with EMG and incentive inspirometry biofeedback in asthmatic adults. A three-group design (Waiting List Control n = 5, RSA biofeedback n = 6, and EMG biofeedback n = 6) was used. Six sessions of training were given in each of the biofeedback groups. In each of three testing sessions, five min. of respiratory resistance and EKG were obtained before and after a 20-min biofeedback session. Additional five-min epochs of data were collected at the beginning and end of the biofeedback period (or, in the control group, self-relaxation). Decreases in respiratory impedance occurred only in the RSA biofeedback group. Traub-Hering-Mayer (THM) waves (.03-.12 Hz) in heart period increased significantly in amplitude during RSA biofeedback. Subjects did not report significantly more relaxation during EMG or RSA biofeedback than during the control condition. However, decreases in pulmonary impedance, across groups, were associated with increases in relaxation. The results are consistent with Vaschillo's theory that RSA biofeedback exercises homeostatic autonomic reflex mechanisms through increasing the amplitude of cardiac oscillations. However, deep breathing during RSA biofeedback is a possible alternate explanation.     

Flux Analysis of Glucose Metabolism in Rhizopus oryzae for the Purpose of Increasing Lactate Yields

A flux analysis of glucose metabolism in the filamentous fungus Rhizopus oryzae was achieved using a specific radioactivity curve-matching program, TFLUX. Glycolytic and tricarboxylic acid cycle intermediates labeled through the addition of extracellular [U-14C]glucose were isolated and purified for specific radioactivity determinations. This information, together with pool sizes and the rates of glucose utilization and end product production, provided input for flux maps of the metabolic network under two different experimental conditions. Based upon the flux analysis of this system, a mutant of R. oryzae with higher lactate and lower ethanol yields than the parent was sought for and found.     

Hemodynamics of the lower extremity with pneumatic foot compression. Effect on leg position]

External pneumatic compression of the foot is being used more and more to increase the venous blood flow in the lower limbs and thus reduce the risk of postoperative deep venous thrombosis. We have investigated the efficacy of the foot pump pneumatic compression device (A-V Impulse, Novamedix, Andover, England) in 10 healthy subjects and in 10 patients undergoing total hip arthroplasty. The velocity of venous blood flow in the common femoral artery was measured in the horizontal, Trendelenburg (head-down, foot-up) and reverse Trendelenburg (head-up and foot-down) positions using a duplex ultrasound unit (Sonoline Elegra, Siemens, Erlangen, Germany) with a 5 MHz linear array probe. Application of the foot pump produced an increase in venous blood flow velocity in all healthy subjects and in all patients. In healthy subjects the mean increase in the horizontal position was 31.18% (SD = 15.86%), and in the Trendelenburg position 20.72 (SD = 15.69%) (right limb). In the reverse Trendelenburg position, the foot pump produced a mean increase of 94.08% (SD = 55.00%). The difference is statistically significant (p < 0.005). In patients with a total hip arthroplasty, the mean increase in the horizontal position was 28.67% (SD = 9.95%), and in the Trendelenburg position 20.34% (SD = 17.85%) (operated limb). In the reverse Trendelenburg, the foot pump produced a mean increase of 91.55% (SD = 42.38%). The difference is statistically significant (p < 0.005). There was no noteworthy difference in results between the controls and patients. Pneumatic compression devices designed to reduce venous stasis are effective in decreasing the rate of deep venous thrombosis after surgery on the lower limb. The results of the present study show that the efficiency of the foot pump in increasing venous return is improved by adopting the reverse Trendelenburg position. This may increase its thromboprophylactic effect.     

Impacts of economic strategies on biotechnological developments

The traditional basis of the processing technologies is profit generation from the transformation of either raw materials or intermediates, using know-how and energy, into marketable products. However, the establishment of both regional economic communities and raw material producer cartels has distorted and even invalidated the economic evaluation of processes in strict economic terms. Essentially, individual countries and regions are moving towards a state of economic protectionism based on specific strategic policies. Such policies are most evident and effective in the agricultural and energy sectors. Biotechnology is intimately linked with both these sectors and major biotechnological ventures have failed as a result of strategic economic changes. This paper examines the basis for the economic evaluation of novel biotechnological processes and seeks to identify politico-economic scenarios that will permit successful establishment of biotechnological processing ventures.