Ordination of epiphytic bryophyte communities in a wet-temperate coniferous forest,South-Coastal British Columbia

Three coniferous tree species (Pseudotsuga menziesii, Tsuga heterophylla, and Thuja plicata) at Capilano Canyon, British Columbia, were studied for their epiphytic communities. Quantitative data were obtained for fourteen bryophyte species by sampling at heights of 0.5 m, 1 m and 2 m above ground level. Scapania bolanderi is an abundant and widely distributed species; Dicranum fuscescens, Bazzania denudata, Lepidozia reptans and Hypnum circinale are also common. An environmentally uniform study area was chosen to minimize the effects of factors other than bark and elevation on the distribution of epiphytes. In general, tree species are similar in terms of their epiphytic assemblages, but ordination methods using quantitative data exposed compositional variation that may be explained by differences in microclimate and bark-type. In this respect, the results point the way to further studies to examine epiphyte associations in closer detail, and to relate these associations to specific factors in the microenvironment.Nomenclature for vascular plants follows Hitchcock & Cronquist (1973); bryophyte nomenclature follows Schofield (1976) for mosses and Stotler & Crandall-Stotler (1977) for hepatics.We thank Dr. W. B. Schofield for aiding in bryophyte identification.     

Symbiont community diversity is more variable in corals that respond poorly to stress

Coral reefs are declining globally as climate change and local water quality press environmental conditions beyond the physiological tolerances of holobionts—the collective of the host and its microbial symbionts. To assess the relationship between symbiont composition and holobiont stress tolerance, community diversity metrics were quantified for dinoflagellate endosymbionts (Family: Symbiodiniaceae) from eight Acropora millepora genets that thrived under or responded poorly to various stressors. These eight selected genets represent the upper and lower tails of the response distribution of 40 coral genets that were exposed to four stress treatments (and control conditions) in a 10‐day experiment. Specifically, four ‘best performer’ coral genets were analyzed at the end of the experiment because they survived high temperature, high pCO₂, bacterial exposure, or combined stressors, whereas four ‘worst performer’ genets were characterized because they experienced substantial mortality under these stressors. At the end of the experiment, seven of eight coral genets mainly hosted Cladocopium symbionts, whereas the eighth genet was dominated by both Cladocopium and Durusdinium symbionts. Symbiodiniaceae alpha and beta diversity were higher in worst performing genets than in best performing genets. Symbiont communities in worst performers also differed more after stress exposure relative to their controls (based on normalized proportional differences in beta diversity), than did best performers. A generalized joint attribute model estimated the influence of host genet and treatment on Symbiodiniaceae community composition and identified strong associations among particular symbionts and host genet performance, as well as weaker associations with treatment. Although dominant symbiont physiology and function contribute to host performance, these findings emphasize the importance of symbiont community diversity and stochasticity as components of host performance. Our findings also suggest that symbiont community diversity metrics may function as indicators of resilience and have potential applications in diverse disciplines from climate change adaptation to agriculture and medicine.     

Positive genetic associations among fitness traits support evolvability of a reef‐building coral under multiple stressors

Climate change threatens organisms in a variety of interactive ways that requires simultaneous adaptation of multiple traits. Predicting evolutionary responses requires an understanding of the potential for interactions among stressors and the genetic variance and covariance among fitness‐related traits that may reinforce or constrain an adaptive response. Here we investigate the capacity of Acropora millepora, a reef‐building coral, to adapt to multiple environmental stressors: rising sea surface temperature, ocean acidification, and increased prevalence of infectious diseases. We measured growth rates (weight gain), coral color (a proxy for Symbiodiniaceae density), and survival, in addition to nine physiological indicators of coral and algal health in 40 coral genets exposed to each of these three stressors singly and combined. Individual stressors resulted in predicted responses (e.g., corals developed lesions after bacterial challenge and bleached under thermal stress). However, corals did not suffer substantially more when all three stressors were combined. Nor were trade‐offs observed between tolerances to different stressors; instead, individuals performing well under one stressor also tended to perform well under every other stressor. An analysis of genetic correlations between traits revealed positive covariances, suggesting that selection to multiple stressors will reinforce rather than constrain the simultaneous evolution of traits related to holobiont health (e.g., weight gain and algal density). These findings support the potential for rapid coral adaptation under climate change and emphasize the importance of accounting for corals’ adaptive capacity when predicting the future of coral reefs.     

Substrate heterogeneity and number of plant species in Everglades savannas (Florida,USA)

Environmental heterogeneity, especially that related to topography, has been proposed to influence numbers of plant species in different sized areas. Despite little variation in elevation, large numbers of vascular plant species occur in some habitats. This study explored possible relationships between number of plant species and substrateheterogeneity in two species-rich habitats, subtropical pine savannas and short-hydroperiod prairies, in the Long Pine Key region of Everglades National Park (Florida, U.S.A.). We examined relationships between numbers of vascular plant species and topographic heterogeneity by measuring numbers of species and elevations in differ-ent sizes of nested plots that spanned five orders of magnitude (0.1 m² to 1000 m² ) and that were located along two transects extending from pine savannas into short-hydroperiod prairies in different areas of Long Pine Key. We also classified substrates and soil depths in 1 m 2 sized submodules within the nested plots. Pine savannas occurred at higher elevations than adjacent short-hydroperiod prairies. Although differences occurred in substrate types and distribution within 1 m 2 plots, numbers of species were not associated with these differences. Vari-ances in elevations were similar in the smallest plots, but increased with area more rapidly in pine savannas than in short-hydroperiod prairies. Plot size explained about 85% of the variation in species numbers, which increased from 2040 per 1 m 2 to 80120 per 1000 m² . An interaction between habitat and scale explained 5% of the variation; more species occurred in shorthydroperiod prairies than pine savannas at scales <10 m² , but the re-verse occurred at scales >10 m². The number of species in pine savannas at scales of 1 m²and 10 m²was positively associated with variation in elevations; no significant relationships were obtained in short-hydroperiod prairies, which lack the fine-scale topographic variation of pine savannas. Our data indicate that substrate het-erogeneity, measured as variation in elevations, is not likely to be involved in the co-occurrence of many species within small areas of these savannas, but may influence numbers of species at larger scales of observation, es-pecially in pine savannas. Why many plant species occur within very small areas in these savannas remains un-answered.     

Classification and management of gynecomastia: defining the role of ultrasound-assisted liposuction

Gynecomastia, or excessive male breast development, has an incidence of 32 to 65 percent in the male population. This condition has important physical and psychological impacts. Advances in elucidating the pathophysiology of gynecomastia have been made, though understanding remains limited. Recommendations for evaluation and workup have varied and are often arbitrary. A diagnostic algorithm is suggested, with emphasis on a comprehensive history, physical examination, and minimizing unnecessary diagnostic testing. Medical management has had limited success; surgical therapy, primarily through excisional techniques, has been the accepted standard. Although effective, excisional techniques subject patients to large, visible scars. Ultrasound-assisted liposuction has recently emerged as a safe and effective method for the treatment of gynecomastia. It is particularly efficient in the removal of the dense, fibrous male breast tissue while offering advantages in minimal external scarring. A new system of classification and graduated treatment is proposed, based on glandular versus fibrous hypertrophy and degree of breast ptosis (skin excess). The authors' series of 61 patients with gynecomastia from 1987 to 2000 at the University of Texas Southwestern Department of Plastic Surgery demonstrated an overall success rate of 86.9 percent using suction-assisted lipectomy (1987 to 1997) and ultrasound-assisted liposuction (1997 to 2000). The authors have found ultrasound-assisted liposuction to be effective in treating most grades of gynecomastia. Excisional techniques are reserved for severe gynecomastia with significant skin excess after attempted ultrasound-assisted liposuction.     

Total soft-tissue reconstruction of the middle and lower face with multiple simultaneous free flaps in a pediatric patient

A 2-year-old boy sustained a massive facial soft-tissue wound secondary to a dog attack. Essentially all the soft tissues of the face were absent, including innervation and intraoral lining. We describe the reconstruction of this defect with five simultaneous free tissue transfers. To our knowledge, this is the first report of five simultaneous free flaps in any patient.     

A prospective analysis of patients undergoing silicone breast implant explantation

Despite the lack of a scientifically proven link between silicone implants and disease, many women have chosen to have their implants removed out of concern for their health. Unfortunately, there are few studies in the literature that have investigated the outcome of explanations, and there are no prospective analyses of the effect explantation has on a patient's general health. The goal of this study was to use a prospective database to determine whether there were any preoperative parameters that could be used to predict which patients would be improved following removal of silicone breast implants and to provide a quantifiable measure of that improvement. A total of 38 patients with silicone breast implants underwent operative removal of their breast implants by faculty at the University of Texas Southwestern Medical Center. They were given questionnaires regarding several personal and medical parameters to be completed preoperatively, at 6 weeks postoperatively, and at 6 months postoperatively. In addition, their physicians completed preoperative and postoperative evaluations of the patient's general health status. A control group of 38 patients was established; they were matched with the experimental group with regard to age and other initial parameters. Their responses to questionnaires were then grouped according to standard subscales to evaluate physical functioning, physical role, bodily pain, general health, vitality, social functioning, emotional role, mental health, appearance evaluation, appearance orientation, illness orientation, and body area satisfaction. When compared with the control group, we found that patients who had undergone explantation showed a temporary decrease in musculoskeletal symptoms and bodily pain, as well as an increase in vitality, mental health, and body area satisfaction. Of the experimental group, those who initially indicated a higher number of musculoskeletal symptoms and a higher appearance evaluation were more likely to indicate a significant improvement in general health since explantation.     

The effects of a low therapeutic dose of βCG fragment-lytic peptide conjugates on ovarian function and gonadotropin secretion in ewes: a randomized controlled trial

The main objective of this experiment was to determine and compare the effects of two lytic peptide conjugates, Phor21-?CG(ala) and ?CG(ala)-Phor21, at a low therapeutic dose (0.2 mg/kg body weight i.v.), on periovulatory ovarian and endocrine activity, and ensuing luteal function in an ovine experimental model. We hypothesized that the dense expression of LH/hCG receptors on the preovulatory follicle would present an appropriate target for the drugs and disrupt normal ovarian dynamics in sheep. Serum levels of reproductive hormones and ultrasonographic images were used for the assessment of periovulatory events following drug administration in 14 Rideau Arcott ewes; seven animals served as controls. Ovulations were synchronized with intravaginal progestogen-releasing sponges (medroxyprogesterone acetate, 60 mg) that were left in place for 12 days and a single i.m. injection of 750 IU of equine chorionic gonadotropin (eCG) given at sponge withdrawal. Both drugs were administered by i.v. injection 36 h post sponge removal/eCG injection, during the period of increasing LH responsiveness of potential ovulatory follicles and around the expected onset of the preovulatory surge of gonadotropins. No difference (p>0.05) was detected in the number of luteal structures per ewe in control versus treated animals during early luteogenesis. After drug administration, peak FSH concentrations were higher (p<0.05) in Phor21-?CG(ala)-treated compared to control ewes and circulating estradiol concentrations were lower (p<0.05) in ?CG(ala)-Phor21-treated animals. Mean serum progesterone concentrations were lower (p<0.05) in ?CG(ala)-Phor21-treated than control ewes during the luteal phase post-treatment. There were no differences (p>0.05) in the percentage of ewes that lambed or lamb characteristics between the three groups at lambing 9 months post-treatment. In summary, neither Phor21-?CG(ala) nor ?CG(ala)-Phor21 demonstrated adverse effects on the ovulatory process but the treatment with ?CG(ala)-Phor21 significantly depressed follicular and luteal steroidogenesis. With a lack of evidence for disruptive effects on endocrine function and fertility, these obsevations support the use of Phor21-?GG(ala) as a cancer pharmaceutical.     

Expert witness reform

The legal system depends on the medical expert for evidence. Doctors readily complain about frivolous cases that go to trial, yet a lawyer cannot bring a frivolous claim to trial without a physician expert witness stating that the claim is not frivolous. An insurance company cannot raise premiums without medical expert witnesses servicing the increasing litigation against the insured. Physicians must look to themselves as a major contributor to rising malpractice insurance costs. For without the physician expert witness, no medical malpractice lawsuit can take place. It is the expert physician, not the attorneys or insurance companies, who defines "meritless" and "frivolous" and who ultimately controls the courts' medical malpractice caseload.     

The effects of intraspinal L-NOARG or SIN-1 on the control by descending pathways of incisional pain in rats

The modulation by spinal nitric oxide (NO) of descending pathways travelling through the dorsal lateral funiculus (DLF) is a mechanism proposed for the antinociceptive effects of drugs that changes the NO metabolism. In this study we confirm that a surgical incision in the mid-plantar hind paw of rats reduces the threshold to mechanical stimulation with von Frey filaments. The incisional pain was further increased in rats with ipsilateral DLF lesion. Intrathecal L-NOARG (50-300 microg), or SIN-1 (0.1-5.0 microg) reduced, while SIN-1 (10 and 20 microg) intensified the incisional pain in rats with sham or effective lesion of the DLF. Stimulation of the dorsal raphe (DRN) or anterior pretectal (APtN) nuclei with stepwise increased electrical currents (7, 14, 21, 28 and 35 microA r.m.s.) produced a current-related reduction of the incisional pain. These nuclei activate pain inhibitory pathways that descend to the spinal cord mainly through the DLF. Intrathecal SIN-1 (5 microg) reduced, SIN-1 (20 microg) decreased and L-NOARG (150 microg) did not change the EC50 for the DRN or APtN stimulation-induced reduction of incisional pain. We conclude that the antinociceptive effects of L-NOARG or low doses of SIN-1 are independent on the activity of descending pain control pathways travelling via the DLF, but the antinociceptive effect of stimulating electrically the DRN or APtN can be summated to the effect of low dose of SIN-1 or overcome by the high dose of SIN-1.