Rafael L. Rodríguez

Bio: Rafael L. Rodríguez is an academic researcher from University of Wisconsin–Milwaukee. The author has contributed to research in topics: Radiative transfer & Sexual selection. The author has an hindex of 38, co-authored 241 publications receiving 5798 citations. Previous affiliations of Rafael L. Rodríguez include University of Valladolid & Technical University of Madrid.

Supplemental perioperative oxygen and the risk of surgical wound infection: a randomized controlled trial.

Abstract: ContextSupplemental perioperative oxygen has been variously reported to halve or double the risk of surgical wound infection.ObjectiveTo test the hypothesis that supplemental oxygen reduces infection risk in patients following colorectal surgery.Design, Setting, and PatientsA double-blind, randomized controlled trial of 300 patients aged 18 to 80 years who underwent elective colorectal surgery in 14 Spanish hospitals from March 1, 2003, to October 31, 2004. Wound infections were diagnosed by blinded investigators using Centers for Disease Control and Prevention criteria. Baseline patient characteristics, anesthetic treatment, and potential confounding factors were recorded.InterventionsPatients were randomly assigned to either 30% or 80% fraction of inspired oxygen (FIO2) intraoperatively and for 6 hours after surgery. Anesthetic treatment and antibiotic administration were standardized.Main Outcome MeasuresAny surgical site infection (SSI); secondary outcomes included return of bowel function and ability to tolerate solid food, ambulation, suture removal, and duration of hospitalization.ResultsA total of 143 patients received 30% perioperative oxygen and 148 received 80% perioperative oxygen. Surgical site infection occurred in 35 patients (24.4%) administered 30% FIO2 and in 22 patients (14.9%) administered 80% FIO2 (P=.04). The risk of SSI was 39% lower in the 80% FIO2 group (relative risk [RR], 0.61; 95% confidence interval [CI], 0.38-0.98) vs the 30% FIO2 group. After adjustment for important covariates, the RR of infection in patients administered supplemental oxygen was 0.46 (95% CI, 0.22-0.95; P = .04). None of the secondary outcomes varied significantly between the 2 treatment groups.ConclusionsPatients receiving supplemental inspired oxygen had a significant reduction in the risk of wound infection. Supplemental oxygen appears to be an effective intervention to reduce SSI in patients undergoing colon or rectal surgery.Trial RegistrationClinicalTrials.gov Identifier: NCT00235456

The Behavioral Ecology of Insect Vibrational Communication

Abstract: Vibrational communication is widespread in insect social and ecological interactions. Of the insect species that communicate using sound, water surface ripples, or substrate vibrations, we estimate that 92% use substrate vibrations alone or with other forms of mechanical signaling. Vibrational signals differ dramatically from airborne insect sounds, often having low frequencies, pure tones, and combinations of contrasting acoustic elements. Plants are the most widely used substrate for transmitting vibrational signals. Plant species can vary in their signal transmission properties, and thus host plant use may influence signal divergence. Vibrational communication occurs in a complex environment containing noise from wind and rain, the signals of multiple individuals and species, and vibration-sensitive predators and parasitoids. We anticipate that many new examples and functions of vibrational communication will be discovered, and that study of this modality will continue to provide important insights into insect social behavior, ecology, and evolution.

Severe Community-Acquired Pneumonia in the Elderly: Epidemiology and Prognosis

Abstract: Ninety-five patients with severe community-acquired pneumonia (SCAP) who were > or = 65 years of age were studied prospectively. A definite pathogen was identified in 37 cases (38.9%) and was most commonly Streptococcus pneumoniae, Haemophilus influenzae, or another gram-negative bacillus. The overall death rate was 40%. Eighty-three patients required mechanical ventilation and 40 needed vasoactive drugs. Multivariate analysis showed that the risk of death was higher in cases involving rapid radiological spread (relative risk [RR] = 6.99; 95% confidence interval (95% CI) = 1.54-31.70), shock (RR = 6.70; 95% CI = 2.13-21.02), previous steroid treatment or immunosuppression (RR = 5.50; 95% CI = 0.77-39.10), acute renal failure (RR = 3.88; 95% CI = 1.30-11.59), or an APACHE II score of > 22 on admission (RR = 2.25; 95% CI = 0.73-6.95). We conclude that SCAP in elderly patients is associated with high mortality, but it is inappropriate to withhold intensive care on account of age. The presence of complications and the severity of illness at initial presentation were the major variables affecting outcome. Except for immunosuppression, comorbidities did not seem to influence outcome. Finally, our data reinforce the current American Thoracic Society guidelines concerning therapy for patients with SCAP.

Asymmetric Block Copolymers with Homopolymers: Routes to Multiple Length Scale Nanostructures

Abstract: positive electrode materials on aflexible substrate such as the paper-type Teflon membrane, atlow-temperatures using soft solution processing without fir-ing/sintering or melting. The results obtained were similar toother deposition processes using fluids such as vapor, gas,plasma, and beam or vacuum processing. Supersaturation andnucleation transfer have been applied to membranes placedat the supersaturation position near the Co working electrode,forming the direct attachment of a positive electrode separa-tor for lithium batteries.

Contributions of natural and sexual selection to the evolution of premating reproductive isolation: a research agenda.

Abstract: Speciation by divergent natural selection is well supported. However, the role of sexual selection in speciation is less well understood due to disagreement about whether sexual selection is a mechanism of evolution separate from natural selection, as well as confusion about various models and tests of sexual selection. Here, we outline how sexual selection and natural selection are different mechanisms of evolutionary change, and suggest that this distinction is critical when analyzing the role of sexual selection in speciation. Furthermore, we clarify models of sexual selection with respect to their interaction with ecology and natural selection. In doing so, we outline a research agenda for testing hypotheses about the relative significance of divergent sexual and natural selection in the evolution of reproductive isolation.

Herbivores and the Number of Tree Species in Tropical Forests

Abstract: A high number of tree species, low density of adults of each species, and long distances between conspecific adults are characteristic of many low-land tropical forest habitats. I propose that these three traits, in large part, are the result of the action of predators on seeds and seedlings. A model is presented that allows detailed examination of the effect of different predators, dispersal agents, seed-crop sizes, etc. on these three traits. In short, any event that increases the efficiency of the predators at eating seeds and seedlings of a given tree species may lead to a reduction in population density of the adults of that species and/or to increased distance between new adults and their parents. Either event will lead to more space in the habitat for other species of trees, and therefore higher total number of tree species, provided seed sources are available over evolutionary time. As one moves from the wet lowland tropics to the dry tropics or temperate zones, the seed and seedling predators in ...

Evolution and the Theory of Games

Abstract: In the Hamadryas baboon, males are substantially larger than females. A troop of baboons is subdivided into a number of ‘one-male groups’, consisting of one adult male and one or more females with their young. The male prevents any of ‘his’ females from moving too far from him. Kummer (1971) performed the following experiment. Two males, A and B, previously unknown to each other, were placed in a large enclosure. Male A was free to move about the enclosure, but male B was shut in a small cage, from which he could observe A but not interfere. A female, unknown to both males, was then placed in the enclosure. Within 20 minutes male A had persuaded the female to accept his ownership. Male B was then released into the open enclosure. Instead of challenging male A , B avoided any contact, accepting A’s ownership.

Monthly Notices of the Royal Astronomical Society

Abstract: Monthly Notices is one of the three largest general primary astronomical research publications. It is an international journal, published by the Royal Astronomical Society. This article 1 describes its publication policy and practice.