One size does not fit all: no evidence for an optimal body size on islands

Aim Optimal body size theories predict that large clades have a single, optimal, body size that serves as an evolutionary attractor, with the full body size spectrum of a clade resulting from interspecific competition. Because interspecific competition is believed to be reduced on islands, such theories predict that insular animals should be closer to the optimal size than mainland animals. We test the resulting prediction that insular clade members should therefore have narrower body size ranges than their mainland relatives. Location World‐wide. Methods We used body sizes and a phylogenetic tree of 4004 mammal species, including more than 200 species that went extinct since the last ice age. We tested, in a phylogenetically explicit framework, whether insular taxa converge on an optimal size and whether insular clades have narrow size ranges. Results We found no support for any of the predictions of the optimal size theory. No specific size serves as an evolutionary attractor. We did find consistent evidence that large (> 10 kg) mammals grow smaller on islands. Smaller species, however, show no consistent tendency to either dwarf or grow larger on islands. Size ranges of insular taxa are not narrower than expected by chance given the number of species in their clades, nor are they narrower than the size ranges of their mainland sister clades – despite insular clade members showing strong phylogenetic clustering. Main conclusions The concept of a single optimal body size is not supported by the data that were thought most likely to show it. We reject the notion that inclusive clades evolve towards a body‐plan‐specific optimum.     

Noncontact dipole effects on channel permeation. III. Anomalous proton conductance effects in gramicidin

Proton transport on water wires, of interest for many problems in membrane biology, is analyzed in side-chain analogs of gramicidin A channels. In symmetrical 0.1 N HCl solutions, fluorination of channel Trp(11), Trp-(13), or Trp(15) side chains is found to inhibit proton transport, and replacement of one or more Trps with Phe enhances proton transport, the opposite of the effects on K(+) transport in lecithin bilayers. The current-voltage relations are superlinear, indicating that some membrane field-dependent process is rate limiting. The interfacial dipole effects are usually assumed to affect the rate of cation translocation across the channel. For proton conductance, however, water reorientation after proton translocation is anticipated to be rate limiting. We propose that the findings reported here are most readily interpreted as the result of dipole-dipole interactions between channel waters and polar side chains or lipid headgroups. In particular, if reorientation of the water column begins with the water nearest the channel exit, this hypothesis explains the negative impact of fluorination and the positive impact of headgroup dipole on proton conductance.     

Production of corticosterone in vitro: role of PGE2

The Authors have studied corticosteron output and tissue levels of cAMP during superfusion with ACTH and/or PGE2 before and after preincubation with indometacin (2 microgram/ml) in beef adrenal glands isolated and superfused with Ringer solution. The Authors on the basis of Mieir studies, conclude that PGE2 can be considered as fixed intermediares of the corticosteroidogenetic action of ACTH.     

Overload and neovascularization of shoulder tendons in volleyball players

ABSTRACT: BACKGROUND: In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the rotator cuff tendons by oximetry. RESULTS: No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) middle hitters (53.7%), opposite hitters (55.5%) and libero players (54.4%) (p<0.05), whereas there was no difference in players with the role of setter (56.2%) (p>0.05). CONCLUSIONS: The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles.     

Assessment and modeling of indoor fungal and bacterial bioaerosol concentrations

In recent years, potentially harmfulmicroorganisms such as Stachybotryschartarum have garnered national attentionwhen implicated with indoor air problems. However, accurate assessment of biologicallycontaminated indoor air has proven to beprohibitively labor, time, cost, and trainingintensive. The model developed in this studyaccurately predicts the levels of biologicalindoor air contaminants for the GreaterCincinnati area using a number of independentvariables that can be quickly calculatedwithout expensive, time-consuming methods. Thirty-nine single-family residences in theGreater Cincinnati area were sampled usingAndersen two-stage viable microbial particlesizing sampler instruments loaded with MaltExtract Agar, Trypicase Soy Agar, Czapek'sCellulose Agar, and Corn Meal Agar. After airsampling, the Petri dishes were incubated, thenumber of colonies from each plate wereenumerated, and the total number of viablecolony forming units per cubic meter of airwere calculated. Independent variables (indoorrelative humidity, indoor temperature, outdoormold, season, water damage, visible mold,damaged materials, home age, remediationfactors, health questionnaire, number ofoccupants, and indoor pets) were then compared tothe dependent variable (fungal and bacterialbioaerosol counts) by multiple linearregression using Analyze-it^® for Microsoft Excel^®. The final air model predicted thetotal number of viable colony forming units percubic meter with 97% accuracy; the goal forthis model was 90% accuracy.     

Spontaneous cell death in the semilunar ganglion during fetal and postnatal life in the ox, sheep, goat and guinea pig.

A massive cell loss occurs in the semilunar ganglion. It is the result of either a casting-off of the semilunar ganglion cells into the cavernous sinus or a transformation of several cells into polyhedral cells with an epithelial-like organization, a process which immediately precedes their further degeneration.     

Effects of some prostaglandins on plasma levels of prolactin in the rat]

In ovariectomized rats treated with estradiol benzoate the ICV introduction of PGE1, 11-deoxy-13,14-didehydro-16S-methyl-PGE2, PGI2 or 6 H-PGI1 produces a marked increase of the plasma prolactin levels. These results suggest that the PGs play a role in the regulation of the prolactin secretion.