Trajectories and tipping points of piñon-juniper woodlands after fire and thinning.

Piñon-juniper (PJ) woodlands are a dominant community type across the Intermountain West, comprising over a million acres and experiencing critical effects from increasing wildfire. Large PJ mortality and regeneration failure after catastrophic wildfire have elevated concerns about the long-term viability of PJ woodlands. Thinning is increasingly used to safeguard forests from fire and in an attempt to increase climate resilience. We have only a limited understanding of how fire and thinning will affect the structure and function of PJ ecosystems. Here, we examined vegetation structure, microclimate conditions, and PJ regeneration dynamics following ~20 years post-fire and thinning treatments. We found that burned areas had undergone a state shift that did not show signs of returning to their previous state. This shift was characterized by (1) distinct plant community composition dominated by grasses; (2) a lack of PJ recruitment; (3) a decrease in the sizes of interspaces in between plants; (4) lower abundance of late successional biological soil crusts; (5) lower mean and minimum daily soil moisture values; (6) lower minimum daily vapor pressure deficit; and (7) higher photosynthetically active radiation. Thinning created distinct plant communities and served as an intermediate between intact and burned communities. More intensive thinning decreased PJ recruitment and late successional biocrust cover. Our results indicate that fire has the potential to create drier and more stressful microsite conditions, and that, in the absence of active management following fire, there may be shifts to persistent ecological states dominated by grasses. Additionally, more intensive thinning had a larger impact on community structure and recruitment than less intensive thinning, suggesting that careful consideration of goals could help avoid unintended consequences. While our results indicate the vulnerability of PJ ecosystems to fire, they also highlight management actions that could be adapted to create conditions that promote PJ re-establishment.

Resistance, Resilience, and Recovery of Dryland Soil Bacterial Communities Across Multiple Disturbances.

Dryland ecosystems are sensitive to perturbations and generally slow to recover post disturbance. The microorganisms residing in dryland soils are especially important as they contribute to soil structure and nutrient cycling. Disturbance can have particularly strong effects on dryland soil structure and function, yet the natural resistance and recovery of the microbial components of dryland soils has not been well documented. In this study, the recovery of surface soil bacterial communities from multiple physical and environmental disturbances is assessed. Samples were collected from three field sites in the vicinity of Moab, UT, United States, 6 to 7 years after physical and climate disturbance manipulations had been terminated, allowing for the assessment of community recovery. Additionally, samples were collected in a transect that included three habitat patches: the canopy zone soils under the dominant shrubs, the interspace soils that are colonized by biological soil crusts, and edge soils at the plot borders. Field site and habitat patch were significant factors structuring the bacterial communities, illustrating that sites and habitats harbored unique soil microbiomes. Across the different sites and disturbance treatments, there was evidence of significant bacterial community recovery, as bacterial biomass and diversity were not significantly different than control plots. There was, however, a small number of 16S rRNA gene amplicon sequence variants that distinguished particular treatments, suggesting that legacy effects of the disturbances still remained. Taken together, these data suggest that dryland bacterial communities may possess a previously unappreciated potential to recover within years of the original disturbance.

Muted responses to chronic experimental nitrogen deposition on the Colorado Plateau.

Anthropogenic nitrogen (N) deposition is significantly altering both community structure and ecosystem processes in terrestrial ecosystems across the globe. However, our understanding of the consequences of N deposition in dryland systems remains relatively poor, despite evidence that drylands may be particularly vulnerable to increasing N inputs. In this study, we investigated the influence of 7 years of multiple levels of simulated N deposition (0, 2, 5, and 8 kg N ha-1 year-1) on plant community structure and biological soil crust (biocrust) cover at three semi-arid grassland sites spanning a soil texture gradient. Biocrusts are a surface community of mosses, lichens, cyanobacteria, and/or algae, and have been shown to be sensitive to N inputs. We hypothesized that N additions would decrease plant diversity, increase abundance of the invasive annual grass Bromus tectorum, and decrease biocrust cover. Contrary to our expectations, we found that N additions did not affect plant diversity or B. tectorum abundance. In partial support of our hypotheses, N additions negatively affected biocrust cover in some years, perhaps driven in part by inter-annual differences in precipitation. Soil inorganic N concentrations showed rapid but ephemeral responses to N additions and plant foliar N concentrations showed no response, indicating that the magnitude of plant and biocrust responses to N fertilization may be buffered by endogenous N cycling. More work is needed to determine N critical load thresholds for plant community and biocrust dynamics in semi-arid systems and the factors that determine the fate of N inputs.

Experimental Warming Changes Phenology and Shortens Growing Season of the Dominant Invasive Plant Bromus tectorum (Cheatgrass).

Bromus tectorum (cheatgrass) has successfully invaded and established throughout the western United States. Bromus tectorum grows early in the season and this early growth allows B. tectorum to outcompete native species, which has led to dramatic shifts in ecosystem function and plant community composition after B. tectorum invades. If the phenology of native species is unable to track changing climate as effectively as B. tectorum's phenology then climate change may facilitate further invasion. To better understand how B. tectorum phenology will respond to future climate, we tracked the timing of B. tectorum germination, flowering, and senescence over a decade in three in situ climate manipulation experiments with treatments that increased temperatures (2°C and 4°C above ambient), altered precipitation regimes, or applied a combination of each. Linear mixed-effects models were used to analyze treatment effects on the timing of germination, flowering, senescence, and on the length of the vegetative growing season (time from germination to flowering) in each experiment. Altered precipitation treatments were only applied in early years of the study and neither precipitation treatments nor the treatments' legacies significantly affected B. tectorum phenology. The timing of germination did not significantly vary between any warming treatments and their respective ambient plots. However, plots that were warmed had advances in the timing of B. tectorum flowering and senescence, as well as shorter vegetative growing seasons. The phenological advances caused by warming increased with increasing degrees of experimental warming. The greatest differences between warmed and ambient plots were seen in the length of the vegetative growing season, which was shortened by approximately 12 and 7 days in the +4°C and +2°C warming levels, respectively. The effects of experimental warming were small compared to the effects of interannual climate variation, suggesting that interactive controls and the timing of multiple climatic factors are important in determining B. tectorum phenology. Taken together, these results help elucidate how B. tectorum phenology may respond to future climate, increasing our predictive capacity for estimating when to time B. tectorum control efforts and how to more effectively manage this exotic annual grass.

Belowground impacts of alpine woody encroachment are determined by plant traits, local climate, and soil conditions.

Global climate and land use change are causing woody plant encroachment in arctic, alpine, and arid/semi-arid ecosystems around the world, yet our understanding of the belowground impacts of this phenomenon is limited. We conducted a globally distributed field study of 13 alpine sites across four continents undergoing woody plant encroachment and sampled soils from both woody encroached and nearby herbaceous plant community types. We found that woody plant encroachment influenced soil microbial richness and community composition across sites based on multiple factors including woody plant traits, site level climate, and abiotic soil conditions. In particular, root symbiont type was a key determinant of belowground effects, as Nitrogen-fixing woody plants had higher soil fungal richness, while Ecto/Ericoid mycorrhizal species had higher soil bacterial richness and symbiont types had distinct soil microbial community composition. Woody plant leaf traits indirectly influenced soil microbes through their impact on soil abiotic conditions, primarily soil pH and C:N ratios. Finally, site-level climate affected the overall magnitude and direction of woody plant influence, as soil fungal and bacterial richness were either higher or lower in woody encroached versus herbaceous soils depending on mean annual temperature and precipitation. All together, these results document global impacts of woody plant encroachment on soil microbial communities, but highlight that multiple biotic and abiotic pathways must be considered to scale up globally from site- and species-level patterns. Considering both the aboveground and belowground effects of woody encroachment will be critical to predict future changes in alpine ecosystem structure and function and subsequent feedbacks to the global climate system.

Differences in root phenology and water depletion by an invasive grass explains persistence in a Mediterranean ecosystem.

PREMISE: Flexible phenological responses of invasive plants under climate change may increase their ability to establish and persist. A key aspect of plant phenology is the timing of root production, how it coincides with canopy development and subsequent water-use. The timing of these events within species and across communities could influence the invasion process. We examined above- and belowground phenology of two species in southern California, the native shrub, Adenostoma fasciculatum, and the invasive perennial grass, Ehrharta calycina to investigate relative differences in phenology and water use. METHODS: We used normalized difference vegetation index (NDVI) to track whole-canopy activity across the landscape and sap flux sensors on individual chaparral shrubs to assess differences in aboveground phenology of both species. To determine differences in belowground activity, we used soil moisture sensors, minirhizotron imagery, and stable isotopes. RESULTS: The invasive grass depleted soil moisture earlier in the spring and produced longer roots at multiple depths earlier in the growing season than the native shrub. However, Adenostoma fasciculatum produced longer roots in the top 10 cm of soil profile in May. Aboveground activity of the two species peaked at the same time. CONCLUSIONS: The fact that Ehrharta calycina possessed longer roots earlier in the season suggests that invasive plants may gain a competitive edge over native plants through early activity, while also depleting soil moisture earlier in the season. Depletion of soil moisture earlier by E. calycina suggests that invasive grasses could accelerate the onset of the summer drought in chaparral systems, assuring their persistence following invasion.

Anesthetic management of mosaic Turner's syndrome posted for elective cesarean delivery after spontaneous pregnancy.

Turner's syndrome, one of the most common sex chromosome abnormalities in females, is caused by loss of part or all of an X chromosome. We report a case of mosaic Turner's syndrome, posted for elective cesarean delivery under low-dose sequential combined spinal-epidural anesthesia. The unique features of this case were the combination of an anticipated difficult airway and both short stature and scoliosis in the lumbar region. A titrated combined spinal-epidural technique was performed in order to avoid hemodynamic instability, which could have been exacerbated in the presence of cardiovascular deformities that accompany this syndrome in many cases. The patient was managed successfully under regional anesthesia, which is generally a preferred technique to general anesthesia, to avoid sympathetic stimulation during intubation and emergence. Further, this technique may avoid potential complications associated with difficult airway management.

Complete longitudinal vaginal septum resection. Description of a bloodless new technique.

PURPOSE OF INVESTIGATION: To describe a novel approach for longitudinal vaginal septum (LVS) resection. Materials and Methods: Two cases of young girls with a uterus didelphys and a longitudinal vaginal septum. The technique consisted in grasping the vaginal septum with a laparoscopic 33-cm long bipolar cutting forceps, five-mm in diameter, and divided it to its midportion towards the two cervices. RESULTS: In both cases, the procedure was straightforward, uncomplicated, completed within three minutes and the patients were discharged four hours later. It was associated with minimal blood loss, short recovery time, absence of local ischemia, and optimum healing process. CONCLUSION: The authors believe that surgical safety, efficacy and operative result make bipolar cutting forceps a tailored option for LVS resection.

The normal vulva in medical textbooks.

When a healthy woman expresses concerns about her vulva, the doctor's response should be informed by clinical knowledge. For many doctors, accumulation of such knowledge would have begun with undergraduate teaching and medical textbooks. The aim of this study is to examine the information on female genital morphology in medical textbooks. A total of 59 gynaecology and anatomy textbooks were searched for information on the dimensions of vulval constitutent parts. No textbook gave measurements for all vulval structures. Vaginal length was reported in 21/59 textbooks, clitoral size in 15/59 and labia minora in 1/59. Where measurements appear, they suggest narrower ranges than recent reports. Information of vulval morphology is scanty and inaccurate in medical textbooks. The general lack of professional resources means that doctors may consciously or non-consciously rely upon personal experiences and popular culture to form their opinions, as do their patients.

Exercise and sedentary habits among adolescents with PCOS.

STUDY OBJECTIVE: The purpose of this study was the recording of physical activity and sedentary habits of adolescents with polycystic ovarian syndrome (PCOS). METHODS: We performed a structured interview to assess the level of physical activity and sedentary habits of girls with PCOS. We used a group of healthy adolescents as controls. All girls had their age, height, weight, hip and waist circumference measured and their BMI calculated. RESULTS: 81 girls (35 with PCOS and 46 controls) participated in the study. Girls with PCOS engaged in physical activities less than controls. Even when they did, the frequency and intensity of exercise was less. Also, girls with PCOS were less likely to be aware of the positive effects of exercise on their health. Girls in both groups were sedentary in excess of the 4 hours per day limit, which has been linked with obesity. CONCLUSION: Healthy teenagers were involved in a sporting activity more often and more frequently than the PCOS group. Athletic and sedentary habits of adolescents with PCOS may interact with other factors leading to obesity.

Clinical characteristics of well women seeking labial reduction surgery: a prospective study.

OBJECTIVE: To assess clinical characteristics and expectations in well women requesting elective labial reduction surgery. DESIGN: Prospective study of women attending an outpatient gynaecology clinic. SETTING: General gynaecology clinic at a Central London teaching hospital. SAMPLE: Women requesting labial reduction surgery and referred by their general practitioner. METHODS: The labia minora width and length were measured for all participants for comparison with published normal values. The presenting complaint was recorded, along with demographic details, expectations of surgery and sources of information regarding appearance of the labia. MAIN OUTCOME MEASURES: Labial measurements, reported symptoms and expectations of surgery. RESULTS: The labia of all participants were within normal published limits, with a mean (SD) of 26.9 (12.8) mm (right labia), and 24.8 (13.1) mm (left labia). The majority of complaints were regarding appearance or discomfort. Expectations were to alter the appearance with surgery. CONCLUSIONS: All women seeking surgery had normal-sized labia minora. Clear guidance is needed for clinicians on how best to care for the worried well woman seeking surgery.

Labial surgery for well women: a review of the literature.

This review investigates the quality and content of published reports relating to labial surgery for well women. Electronic databases were searched for relevant articles between 1950 and April 2009. Forty articles were identified, 18 of which included patient data. The specification of the study design was unavailable in 15 of the 18 papers; the remaining three were retrospective reports. No prospective, randomised or controlled studies were found. All reports claimed high levels of patient satisfaction and contained anecdotes pertaining to success. Medically nonessential surgery to the labia minora is being promoted as an effective treatment for women's complaints, but no data on clinical effectiveness exist.

The clandestine uterus: or how the uterus escapes detection prior to puberty.

Uterine agenesis is one of the differential diagnoses in adolescent girls with delayed menstruation. It may also be suspected earlier in childhood during investigations for other genitourinary conditions. However, accurate confirmation that the uterus is absent can be extremely difficult before puberty because of its small size. We describe ten girls referred to a specialist centre with a presumed diagnosis of an absent uterus which was later found to be incorrect. We conclude that imaging should be undertaken by clinicians with experience in management of this age group and in some girls it may be necessary to delay final diagnosis until after puberty.

Minimal access surgery in adolescent gynaecology.

The benefits of a minimally invasive approach are now well documented in adult women, and thus surgeons have embraced the notion of expanding such expertise in adolescence with measured enthusiasm and a great sense of responsibility. Faster recovery is likely to have a positive impact on schooling, while less adhesion formation may reduce future fertility issues. Gynaecologists performing minimally invasive procedures in adolescents ought to be aware of the steep learning curve required for achieving proficiency with complex laparoscopic surgery. In the group of rare congenital anomalies and advanced endometriosis, the best surgical results can only be achieved after careful preoperative planning by a multidisciplinary team.

Swyer syndrome: presentation and outcomes.

OBJECTIVE: To establish the spectrum of presentation, natural history and gynaecological outcomes in women with Swyer syndrome. DESIGN: Retrospective notes review. SETTING: Tertiary referral centre for disorders of sex development. POPULATION: A total of 29 adult women with Swyer syndrome. METHODS: Information was collected on age at diagnosis, biometric characteristics, timing of gonadectomy, histology of gonad, bone mineral density, uterine size and fertility. MAIN OUTCOME MEASURES: Age at diagnosis, risk of gonadal malignancy, bone mineral density, uterine size. RESULTS: With regard to presentation, 26/29 (90%) women in this series presented with delayed puberty, and the median age at diagnosis was 17.2 years (range 0-55 years). The median age at gonadectomy was 18 years (range 9-33 years). Histology of the gonad was available in 22 women and demonstrated streak gonads with no evidence of malignancy in 12, dysgerminoma in 7 and gonadoblastoma in 3. The youngest patient diagnosed with dysgerminoma was 10 years old. The median height of the women was 1.73 m (range 1.54-1.95 m). Twelve out of the 20 (60%) women had evidence of osteopenia on dual energy X-ray absorptiometry scan. The uterine size and shape was assessed in eight women after completion of induction of puberty, and the uterine cross-section was found to be significantly lower than that in normal controls. Fertility was achieved with ovum donation in three women, all of whom had live births and one subsequently had a second successful pregnancy. CONCLUSION: Early diagnosis of Swyer syndrome is necessary in view of the risk of dysgerminoma that can develop at an early age. Adequate hormone replacement is required to maintain bone mineral density and may improve the uterine size and shape.

Transfusion-related acute lung injury (TRALI) in an obstetric patient.

Transfusion-related lung injury (TRALI) is the leading cause of mortality following transfusion of blood products. Despite increasing awareness, the condition often remains unrecognised and therefore underreported. A 28-year-old with moderate preeclampsia had a post-partum haemorrhage following emergency caesarean section. Shortly after receiving three units of packed red cells she went into respiratory failure, which progressed to cardiac arrest. She was successfully resuscitated and made a slow but full recovery. Investigation through the National Blood Service confirmed the diagnosis of TRALI. TRALI is an increasingly common life-threatening complication of blood transfusion and should be included in the differential diagnosis of collapse in an obstetric patient who has recently received a blood product transfusion.