Multifractal characterization of morphology of human red blood cells membrane skeleton.

The purpose of this paper is to show applicability of multifractal analysis in investigations of the morphological changes of ultra-structures of red blood cells (RBCs) membrane skeleton measured using atomic force microscopy (AFM). Human RBCs obtained from healthy and hypertensive donors as well as healthy erythrocytes irradiated with neutrons (45 µGy) were studied. The membrane skeleton of the cells was imaged using AFM in a contact mode. Morphological characterization of the three-dimensional RBC surfaces was realized by a multifractal method. The nanometre scale study of human RBCs surface morphology revealed a multifractal geometry. The generalized dimensions Dq and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of their membrane skeleton organization. Surface characterization was made using areal ISO 25178-2: 2012 topography parameters in combination with AFM topography measurement. The surface structure of human RBCs is complex with hierarchical substructures resulting from the organization of the erythrocyte membrane skeleton. The analysed AFM images confirm a multifractal nature of the surface that could be useful in histology to quantify human RBC architectural changes associated with different disease states. In case of very precise measurements when the red cell surface is not wrinkled even very fine differences can be uncovered as was shown for the erythrocytes treated with a very low dose of ionizing radiation.

Placental transfer of IgG antibodies specific to Klebsiella and Pseudomonas LPS and to group B Streptococcus in twin pregnancies.

Group B Streptococcus (GBS), Klebsiella spp. and Pseudomonas spp. are important aetiological agents of neonatal infections in Brazil. There is a lack of data in the literature regarding the specific transport of immunoglobulin G (IgG) against these pathogens in multiple pregnancies. Maternal (n = 55) and umbilical cord (n = 110) blood samples were prospectively collected at birth from 55 twin pregnancies. The factors associated with cord levels and transfer ratios of IgG against GBS, Klebsiella and Pseudomonas were examined. The IgG umbilical cord serum levels specific to GBS, Klebsiella LPS and Pseudomonas LPS were significantly associated with maternal-specific IgG concentrations and the presence of diabetes. The anti-Klebsiella IgG cord serum concentrations were also related to birthweight and the presence of hypertension. The transfer ratios against GBS and Pseudomonas LPS were associated with maternal-specific IgG concentrations. The transfer ratios for GBS and Pseudomonas LPS were associated with gestational age at delivery and the presence of diabetes, respectively. None of the examined parameters were related to Klebsiella LPS transfer ratios. We conclude that in twin pregnancies, specific maternal IgG serum concentrations and diabetes were the parameters associated with umbilical cord serum IgG concentrations reactive with the three pathogens investigated. All the other parameters investigated showed different associations with neonatal-specific IgG levels according to the antigen studied. There was no uniformity of the investigated parameters regarding association with placental IgG transfer ratios against the GBS, Pseudomonas LPS and Klebsiella LPS.

The automatic pilot of honeybees.

Using scanning harmonic radar, we make visible for the first time the complete trajectories of "goal-vector" flights in honeybees. We demonstrate that bees captured at an established feeding station, and released elsewhere, nevertheless embark on the previously learned vector flight that would have taken them directly home from the station, had they not been artificially displaced. Almost all of the bees maintained accurate compensation for lateral wind drift, and many completed the full length of the vector flight before starting to search for their hive. Our results showed that bees tend to disregard landscape cues during these vector flights, at least initially, and rely on the "optic flow" of the ground beneath them, and their sun compass, to judge both direction and distance.

Improving self-care in adults with asthma using peak expiratory flow rate home monitoring.

Asthma management is based on step therapy incorporated into an individualized patient treatment plan. Medication selection is based on differing degrees of asthma severity. With proper assessment of the patient and a severity level incorporating the patient's needs, a clinician can create a credit card treatment plan for each patient. The assessment should include both PEFR and symptom monitoring as a means of incorporating the CDC's severity guidelines and treatment options into the credit card plan. Evaluation of technique, review of home monitoring outcomes, and reinforcement during clinic visits is likely to be helpful for those patients who do home monitoring. Note, however, that not all patients should be treated using this self-management approach. Asthma associated with comorbidities may be a reason to manage patients more closely either by clinic visit or telephone. Asthma in both older and pregnant patients presents issues of drug safety (Evans, Brown, & Morain, 1997). The common comorbidities of chronic obstructive pulmonary disease, sinusitis, GERD, cardiovascular disease and diabetes present unique issues of difficulty of diagnosis and drug safety. By following individualized asthma management plans, patients should be able to achieve prevention or reduction of chronic symptoms. They should also notice an improvement in physical activity, the reduction or elimination of exacerbations and improved overall satisfaction.

Pattern learning by honeybees: conditioning procedure and recognition strategy.

In recognizing a pattern, honeybees Apis mellifera, may focus either on its ventral frontal part, or on the whole frontal image. We asked whether the conditioning procedure used to train the bees to a pattern determines the recognition strategy employed. Bees were trained with the same patterns presented vertically on the back walls of a Y maze. Conditioning was either absolute, that is, bees should learn to choose a rewarded pattern when there is no alternative, or differential, that is, bees should learn to choose a rewarded pattern that is paired with a different, nonrewarded one. Bees used different pattern recognition strategies depending on the conditioning procedure: absolute conditioning restricted recognition to the lower half whilst differential conditioning extended it to the whole pattern. Bees trained with absolute conditioning saw and learned the features of the upper part of the trained patterns, but assigned more weight to the lower part. Bees trained with differential conditioning learned not only the features of the reinforced stimulus in an excitatory way, but also those of the nonreinforced one in an inhibitory way. Thus, conditioning tasks that involve not only excitatory acquisition of the conditioned stimulus per se, but also discrimination of nonreinforced stimuli, result in an increase in the visual field assigned to the recognition task. Conditioning tasks that involve only excitatory acquisition of the rewarded stimulus result in a higher weighting of the lower pattern half and thus in a more reduced field assigned to the recognition task. This difference may reflect that existing between a conditioned and an incidental behavioural modification. Copyright 1999 The Association for the Study of Animal Behaviour.