Fluctuation Spectroscopy Analysis of Glucose Capped Gold Nanoparticles.

In this work, we report the synthesis and biophysical studies carried out on a new kind of biocompatible and very stable gold nanoparticle (GNP) stabilized with glucose through a PEG linker (AuNP-PEG-Glu). The synthetic path was optimized to obtain nanoparticles of controlled sizes. ζ-potential and dynamic light scattering measurements allowed assessment of the nanodimension, dispersity, surface charge, and stability of our GNPs. Confocal microscopy demonstrated qualitatively that glucose molecules are successfully bonded to GNP surfaces. For our study, we selected nanoparticles with diameter in a range that maximizes the internalization efficiency in cells (40 nm). A detailed investigation about the biophysical proprieties of AuNP-PEG-Glu was carried out by means of fluorescence correlation spectroscopy (FCS) and orbital tracking techniques. This work gives new insights about the uptake mechanism of gold nanoparticles capped with glucose molecules.

Risk mapping for sensitive species to underwater anthropogenic sound emissions: model development and validation in two Mediterranean areas.

Recent observations of cetacean mass strandings, coincident with anthropogenic sounds emissions, have raised concerns on the potential environmental impact of underwater noise. Cuvier's beaked whale (Ziphius cavirostris) was reported in all the cited stranding events. Within the NATO Marine Mammal Risk Mitigation project (MMRM), multiple interdisciplinary sea trials have been conducted in the Mediterranean Sea with the objective of developing tools and procedures to mitigate the impact of underwater sound emissions. During these cruises, visual observations, passive acoustic detections and environmental data were collected. The aim of this study was to evaluate "a priori" predictions of Cuvier's beaked whale presence in the Alboran Sea, using models developed in the Ligurian Sea that employ bathymetric and chlorophyll features as predictors. The accuracy of these predictions was found adequate and elements are given to account for the uncertainties associated to the use of models developed in areas different from their calibration site.

Electrical conductivity of nonideal carbon and zinc plasmas: experimental and theoretical results.

Electrical conductivities of nonideal carbon and zinc plasmas have been measured in this paper. The plasma is produced by vaporizing a wire placed in a glass capillary within some hundred nanoseconds. In the case of carbon, vaporization occurs with good reproducibility when utilizing a preheating system. The particle density is in the range of n=(1-10) x 10(21) cm(-3). The plasma temperature, which is obtained by fitting a Planck function to the measured spectrum, is between 7-15 kK. Plasma radius and behavior of the plasma expansion were studied with a streak, a framing or an intensified charge coupled device camera. We compare the measured electrical conductivities with theoretical results, which were obtained solving quantum kinetic equations for the nonideal partially ionized plasmas. In this approach, the transport cross sections are calculated on the level of a T-matrix approximation using effective potentials. The plasma composition is determined from a system of coupled mass action laws with nonideality corrections.

Electrical conductivity measurements of strongly coupled W plasmas.

Nonideal plasmas of tungsten were produced by vaporizing thin wires of 0.1 mm and 0.3 mm in diameter in small glass capillaries (in air) by means of a short-pulse current from an electrical discharge. For a short period of time, the inner wall of the rigid glass capillary confines the plasma until the induced pressure shock wave disintegrates the capillary. Spectroscopic measurements were carried out on the ejected plasma close to the end of the capillary. The plasma temperature was obtained by fitting a Planck function to the measured continuum spectrum. The resistance was derived from the voltage across the plasma and the current through the plasma. The plasma radius was determined with an intensified charge-coupled device camera and a streak camera and allowed the derivation of the conductivity. Particle densities were of the order of 10(22) particle/cm(3) and electron temperatures were in the range from 10 kK to 22 kK. These measurements are compared with theoretical models and previous work.

A killer appetite: metabolic consequences of carnivory in marine mammals.

Among terrestrial mammals, the morphology of the gastrointestinal tract reflects the metabolic demands of the animal and individual requirements for processing, distributing, and absorbing nutrients. To determine if gastrointestinal tract morphology is similarly correlated with metabolic requirements in marine mammals, we examined the relationship between basal metabolic rate (BMR) and small intestinal length in pinnipeds and cetaceans. Oxygen consumption was measured for resting bottlenose dolphins and Weddell seals, and the results combined with data for four additional species of carnivorous marine mammal. Data for small intestinal length were obtained from previously published reports. Similar analyses were conducted for five species of carnivorous terrestrial mammal, for which BMR and intestinal length were known. The results indicate that the BMRs of Weddell seals and dolphins resting on the water surface are 1.6 and 2.3 times the predicted levels for similarly sized domestic terrestrial mammals, respectively. Small intestinal lengths for carnivorous marine mammals depend on body size and are comparatively longer than those of terrestrial carnivores. The relationship between basal metabolic rate (kcal day(-1)) and small intestinal length (m) for both marine and terrestrial carnivores was, BMR=142.5 intestinal length(1.20) (r(2)=0.83). We suggest that elevated metabolic rates among marine mammal carnivores are associated with comparatively large alimentary tracts that are presumably required for supporting the energetic demands of an aquatic lifestyle and for feeding on vertebrate and invertebrate prey.

Recommendations for Telephone Counseling.

Telephone counseling can provide a convenient, accessible, and valuable source of information to the general public, health care providers, and other professionals. In the genetic counseling profession, telephone counseling is often associated with teratogen information services. However, genetic counselors routinely utilize the telephone in a number of different counseling encounters. Nevertheless, the literature provides very little guidance to how that encounter might be conducted, what information should be obtained and provided, or how the encounter should be documented. We present a brief overview of the history of telephone counseling, a description of the major differences between telephone counseling and a face-to-face counseling session, and a framework to optimize a telephone counseling session.

The diving physiology of bottlenose dolphins (Tursiops truncatus). I. Balancing the demands of exercise for energy conservation at depth.

During diving, marine mammals must rely on the efficient utilization of a limited oxygen reserve sequestered in the lungs, blood and muscles. To determine the effects of exercise and apnea on the use of these reserves, we examined the physiological responses of adult bottlenose dolphins (Tursiops truncatus) trained to breath-hold on the water surface or to dive to submerged targets at depths between 60 and 210 m. Changes in blood lactate levels, in partial pressures of oxygen and carbon dioxide and in heart rate were assessed while the dolphins performed sedentary breath-holds. The effects of exercise on breath-hold capacity were examined by measuring heart rate and post-dive respiration rate and blood lactate concentration for dolphins diving in Kaneohe Bay, Oahu, Hawaii. Ascent and descent rates, stroke frequency and swimming patterns were monitored during the dives. The results showed that lactate concentration was 1.1+/-0.1 mmol l(-1) at rest and increased non-linearly with the duration of the sedentary breath-hold or dive. Lactate concentration was consistently higher for the diving animals at all comparable periods of apnea. Breakpoints in plots of lactate concentration and blood gas levels against breath-hold duration (P(O2), P(CO2)) for sedentary breath-holding dolphins occurred between 200 and 240 s. In comparison, the calculated aerobic dive limit for adult dolphins was 268 s. Descent and ascent rates ranged from 1.5 to 2.5 m s(-1) during 210 m dives and were often outside the predicted range for swimming at low energetic cost. Rather than constant propulsion, diving dolphins used interrupted modes of swimming, with more than 75 % of the final ascent spent gliding. Physiological and behavioral measurements from this study indicate that superimposing swimming exercise on apnea was energetically costly for the diving dolphin but was circumvented in part by modifying the mode of swimming.

An assessment of teratology training provided by masters level genetic counseling programs.

The increasing demand in the clinical genetics setting for information about teratogen exposures has created a need for genetic counselors to have the capabilities to appropriately address patient concerns. In order to assess how training in teratogen counseling is currently being conducted, the GLaRGG Teratogen Subcommittee surveyed all 17 genetic counseling training programs in North America in September 1993. Information was obtained from training programs about coursework, resources, and clinical training. In addition, each training program was asked to provide information about how their teratogen training needs could better be met. While all programs responded that some information in their coursework applicable to teratogen counseling was provided, there was wide variation in the amount of time devoted to this topic. The programs also greatly differed in the provision of clinical training in teratogen counseling. For both coursework and clinical work, genetic counselors were the main trainers in teratogen counseling. In spite of this, fewer than 25% of training programs have a defined teratogen clinical rotation. Data from the survey are discussed and recommendations presented.

Temporal evolution of risk estimates for presumed human teratogens.

We present preliminary data assessing a previously untried method of deriving estimates of risk from case reports on presumed human teratogens. We postulated that we could take advantage of biases inherent to case reports in order to generate one or more families of temporal curves that could be used to estimate the "true" risk of teratogenic exposure. Using this method (which we refer to as the "case-cumulative method") we found that two agents (parvovirus B19 and isotretinoin) demonstrated a logarithmic decrease in the estimated risk over time, as intuitively expected, while trimethadione and the coumarin derivatives showed a more complex pattern over time. Analysis of estimated risks quoted by reviews and large studies for these four agents showed large variability from estimate to estimate and no discernible temporal pattern. With further analysis of other agents, the case-cumulative method might eventually prove to be useful in teratogen counseling.

The physiology of bottlenose dolphins (Tursiops truncatus): heart rate, metabolic rate and plasma lactate concentration during exercise.

Despite speculation about the swimming efficiency of cetaceans, few studies have investigated the exercise physiology of these mammals. In view of this, we examined the physiological responses and locomotor energetics of two exercising adult Tursiops truncatus. Oxygen consumption, heart rate, respiratory rate and post-exercise blood lactate concentration were determined for animals either pushing against a load cell or swimming next to a boat. Many of the energetic and cardiorespiratory responses of exercising dolphins were similar to those of terrestrial mammals. Average heart rate, respiratory rate and oxygen consumption for dolphins pushing against a load cell increased linearly with exercise levels up to 58 kg for a female dolphin and 85 kg for a male. Oxygen consumption did not increase with higher loads. Maximum rate of oxygen consumption (VO2max) ranged from 19.8 to 29.4 ml O2 kg-1 min-1, which was 7-11 times the calculated standard metabolic rate (VO2std) of the dolphins. Blood lactate concentration increased with exercise loads that exceeded VO2max. The maximum lactate concentration was 101.4 mg dl-1 (11.3 mmol l-1) for the male, and 120.6 mg dl-1 (13.6 mmol l-1) for the female. When swimming at 2.1 m s-1, heart rate, respiratory rate and post-exercise blood lactate concentration of the dolphins were not significantly different from values at rest. The cost of transport at this speed was 1.29 +/- 0.05 J kg-1 min-1. The energetic profile of the exercising bottlenose dolphin resembles that of a relatively sedentary mammal if the exercise variables defined for terrestrial mammals are used. However, the energetic cost of swimming for this cetacean is low in comparison to that of other aquatic and semi-aquatic mammals.

A process for objective review of physician performance.

How do you objectively evaluate physicians at reappointment. How do you establish a common ground for the evaluation process that still acknowledges acceptable differences in performance? Perhaps one physician has some difficulty with documentation and attendance at meetings, but has no quality problems clinically. Another physician may have good documentation and meeting attendance, but has some quality problems. Another physician has a behavior pattern that is disruptive, a few documentation problems, but excellent quality. Yet another physician is a marginal practitioner with major problems in several areas, including quality. Reappointment of these physicians might be extremely difficult, especially if the credentials committee is recently appointed and not familiar with the details of the performance data.

Travel at low energetic cost by swimming and wave-riding bottlenose dolphins.

Over the past 50 years there has been much speculation about the energetic cost of swimming and wave-riding by dolphins. When aligned properly in front of the bow of moving ships in the stern wake of small boats, on wind waves, and even in the wake of larger cetaceans, the animals appear to move effortlessly through the water without the benefit of propulsive strokes by the flukes. Theoretically, body streamlining as well as other anatomical and behavioural adaptations contribute to low transport costs in these animals. The economy of movement permitted by wave-riding has been perceived as an energetic advantage for the swimming dolphin, but has been hard to prove in the absence of physiological data for exercising cetaceans. Here we determine the aerobic and anaerobic costs of swimming and wave-riding in bottlenose dolphins and find that the minimum cost of transport for swimming dolphins is 1.29 +/- 0.05 J kg-1 m-1 at a cruising speed of 2.1 m s-1. Aerobic costs are nearly twice as high for swimming seals and sea lions, and 8-12 times higher for human swimmers. Wave-riding by dolphins provides additional benefits in terms of speed. The results indicate that behavioural, physiological and morphological factors make swimming an economical form of high-speed travel for dolphins.

The importance of luminal factors in neomucosal growth.

Growing neomucosa on patched intestinal defects has been investigated as a method of expanding the intestinal absorptive area. The purpose of this study was to determine the effect of luminal factors on the rate of growth and function of neomucosa in rabbit ileum. A 2 X 5-cm distal ileal defect was patched with adjacent colon serosa in 10 New Zealand white male rabbits. A similar defect was patched in a bypassed ileal segment in an additional 10 rabbits. Five animals in each group were sacrificed at 4 and 8 weeks for determination of the gross and microscopic growth of neomucosa, glucose uptake, and disaccharidase activity. In addition, tritiated thymidine uptake was measured in neomucosa and incontinuity ileum at the 4-week sacrifice. Grossly, the patched defects were covered in nearly all animals by 4 weeks and coverage was complete at 8 weeks. Microscopically, the mucosa was less well developed in the bypassed group with a mean villous height significantly less than the incontinuity group (139.9 +/- 13.9 microns vs 212.33 +/- 30.3 microns, P less than 0.0005). In vitro uptake of [3H]thymidine was significantly higher in neomucosa in bypassed segments when compared with neomucosa in incontinuity segments (692.5 +/- 347.8 vs 278.0 +/- 134.8, P less than .05, expressed as percentage of normal incontinuity ileum). Glucose uptake was similar in both groups but disaccharidase activity was significantly less in the bypassed group. The increased uptake of [3H]thymidine in neomucosa in the bypassed segment may reflect the histologic immaturity of this tissue with a greater proportion of DNA synthesizing cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adequate diet prevents hepatic coma in dogs with Eck fistulas.

The conventional animal model of human portal systemic encephalopathy is the dog with Eck fistula. Dogs fed standard dog chow after Eck fistula manifest anorexia, weight loss, hepatic atrophy and encephalopathy. This study was done to determine the natural history of dogs undergoing Eck fistulas when adequate nutrition is maintained with a palatable diet. Twenty-four mongrel dogs were divided into four groups--Eck fistula fed standard dry dog chow (EF-SC) (n equals nine); sham operated fed standard chow (SO-SC) (n equals five); Eck fistula fed a liquid (Isocal) diet (EF-LD), LD), and sham operated fed a liquid diet (SO-LD) (n equals five). Dogs were sacrificed when they had clinical signs of encephalopathy or up to 120 days after operation. EF-SC dogs had a daily caloric intake approximately 40 per cent of that of the other groups. Two EF-SC dogs died of sepsis within two weeks of the operation, the other seven became encephalopathic between 46 and 91 days (a mean of 63.6 +/- 15.6). No other dogs had signs of neurologic deterioration. EF-SC dogs lost 19 +/- 9 per cent body weight and the serum albumin level decreased 14.5 per cent while the other groups maintained body weight and serum albumin levels. Both EF-SC and EF-LD groups had decreased liver weight to body weight ratios (LW X 100/BW) compared with sham operated upon dogs reflecting hepatic atrophy (1.97 +/- 0.7 and 2.2 +/- 0.23 versus 3.04 +/- 0.85 and 3.48 +/- 0.44). Results of histologic examination of the liver revealed hepatocyte atrophy, deglycogenation and lipid accumulation in EF dogs. We conclude from these data that providing dogs with Eck fistula a palatable diet prevents weight loss and malnutrition, but not hepatic atrophy. The lack of neurologic signs in well nourished dogs suggests to us that data concerning hepatic coma from the standard Eck fistula model should be interpreted with extreme caution.

Comparison of needle catheter versus standard tube jejunostomy.

It is commonly stated that needle catheter jejunostomy (NCJ) is associated with fewer complications than standard tube jejunostomy (STJ). We compared the morbidity of NCJ versus STJ performed as adjunctive procedures in 90 patients from 1977 to 1983. NCJ was performed in 55 patients and STJ in 35 patients. The two groups were similar with respect to age, sex, diagnosis, and operation performed. The overall postoperative morbidity was 35 per cent for the NCJ group and 62 per cent for the STJ group. Mortality was 19 per cent and 35 per cent, respectively. Minor complications related to the jejunostomy occurred in 16 per cent of the NCJ group and 9 per cent of the STJ group. Diarrhea and abdominal distention occurred with equal frequency in the two groups. One NCJ patient required reoperation for intestinal obstruction at the catheter exit site, and one STJ patient required operative closure of a fistula following tube removal for major complications rates of 1.8 per cent and 2.8 per cent, respectively. The statement that STJ is associated with more jejunostomy-related complications than NCJ is not substantiated by this study. Because of greater ease of insertion, NCJ remains our procedure of choice for adjunctive feeding jejunostomy.