Mechanisms of systemic resistance to pathogen infection in plants and their potential application in forestry.

BACKGROUND: The complex systemic responses of tree species to fight pathogen infection necessitate attention due to the potential for yield protection in forestry. RESULTS: In this paper, both the localized and systemic responses of model plants, such as Arabidopsis and tobacco, are reviewed. These responses were compared to information available that investigates similar responses in woody plant species and their key differences were highlighted. In addition, tree-specific responses that have been documented were summarised, with the critical responses still relying on certain systemic acquired resistance pathways. Importantly, coniferous species have been shown to utilise phenolic compounds in their immune responses. Here we also highlight the lack of focus on systemic induced susceptibility in trees, which can be important to forest health. CONCLUSIONS: This review highlights the possible mechanisms of systemic response to infection in woody plant species, their potential applications, and where research may be best focused in future.

Value of prolonged scrotal drainage after penile prosthesis implantation: a multicenter prospective nonrandomized pilot study.

We aimed to understand the risks and benefits of post-inflatable penile prosthesis (IPP) implantation drainage and optimal duration. Our patients were divided into 3 groups: Group 1 (n = 114) had no drain placed, Group 2 had a drain placed for 24 h (n = 114) and Group 3 had a drain placed for 72 h (n = 117). Postoperative scrotal hematoma and prosthesis infection rates were compared between the groups. The patients from Group 3 demonstrated a statistically significant lower incidence of hematoma on the 10th postoperative day: (n = 1, 0.9%) compared to Group 2: (n = 11, 9.6%) and Group 1: (n = 8, 7%), (p = 0.013). However, on the 3rd postoperative day, there was a statistically significant lower incidence of hematoma in both Groups 3 and 2: (0.9% and 6.1%, respectively) vs. Group 1: (11.4%), (p = 0.004). Hematoma rates followed the same group order after the first day of surgery: 1.7% (n = 2), 5.3% (n = 6), and 8.8% (n = 10), respectively, (p = 0.05). Five patients (4.4%) in Group 1 and four patients (3.5%) in Group 2 developed an IPP associated infection, opposed to only a single patient (0.85%) in Group 3, (p = 0.210). We concluded that prolonged scrotal drainage for 72 h after virgin IPP implantation significantly reduces hematoma and infection rates.

Anatomic considerations of inflatable penile prosthetics: lessons gleaned from surgical body donor workshops.

Surgical implantation of an inflatable penile prosthesis (IPP) remains the gold-standard treatment for severe erectile dysfunction. The ideal surgical technique requires a thorough understanding of the relevant anatomy. This includes anatomic considerations related to, but not limited to, dissection and exposure of penoscrotal fasciae and tissues, corporal configuration, and abdominal structures. Insights obtained from pre-dissected anatomic specimens can obviate urethral injury, nerve damage, corporal perforation, inappropriate sizing, crossover, or implant malposition. We present penile implant-specific anatomic dissections and topographic landmarks identified over the last decade in the course of surgical training programs provided for IPP implantation.

Transient flow-driven distortion of a nematic liquid crystal in channel flow with dissipative weak planar anchoring.

Motivated by the one-drop-filling (ODF) method for the industrial manufacturing of liquid crystal displays, we analyze the pressure-driven flow of a nematic in a channel with dissipative weak planar anchoring at the boundaries of the channel. We obtain quasisteady asymptotic solutions for the director angle and the velocity in the limit of small Leslie angle, in which case the key parameters are the Ericksen number and the anchoring strength parameter. In the limit of large Ericksen number, the solution for the director angle has narrow reorientational boundary layers and a narrow reorientational internal layer separated by two outer regions in which the director is aligned at the positive Leslie angle in the lower half of the channel and the negative Leslie angle in the upper half of the channel. On the other hand, in the limit of small Ericksen number, the solution for the director angle is dominated by splay elastic effects with viscous effects appearing at first order. As the Ericksen number varies, there is a continuous transition between these asymptotic behaviors, and in fact the two asymptotic solutions capture the behavior rather well for all values of the Ericksen number. The steady-state value of the director angle at the boundaries and the timescale of the evolution toward this steady-state value in the asymptotic limits of large and small Ericksen number are determined. In particular, using estimated parameter values for the ODF method, it is found that the boundary director rotation timescale is substantially shorter than the timescale of the ODF method, suggesting that there is sufficient time for significant transient flow-driven distortion of the nematic molecules at the substrates from their required orientation to occur.

Advection and Taylor-Aris dispersion in rivulet flow.

Motivated by the need for a better understanding of the transport of solutes in microfluidic flows with free surfaces, the advection and dispersion of a passive solute in steady unidirectional flow of a thin uniform rivulet on an inclined planar substrate driven by gravity and/or a uniform longitudinal surface shear stress are analysed. Firstly, we describe the short-time advection of both an initially semi-infinite and an initially finite slug of solute of uniform concentration. Secondly, we describe the long-time Taylor-Aris dispersion of an initially finite slug of solute. In particular, we obtain the general expression for the effective diffusivity for Taylor-Aris dispersion in such a rivulet, and discuss in detail its different interpretations in the special case of a rivulet on a vertical substrate.

Assessing coral health and disease from digital photographs and in situ surveys.

Methods for monitoring the status of marine communities are increasingly adopting the use of images captured in the field. However, it is not always clear how data collected from photographic images relate to historic data collected using traditional underwater visual census methods. Here, we compare coral health and disease data collected in situ by scuba divers with photographic images collected simultaneously at 12 coral reef sites. Five globally relevant coral diseases were detected on 194 colonies from in situ surveys and 79 colonies from photos, whilst 698 colonies from in situ surveys and 535 colonies from photos exhibited signs of compromised health other than disease. Comparisons of in situ surveys with photographic analyses indicated that the number of disease cases occurring in the examined coral populations (prevalence) was six times higher (4.5 vs. 0.8% of colonies), whilst compromised health was three times higher (14 vs. 4% of colonies) from in situ surveys. Skeletal eroding band disease, sponge overgrowth and presence of Waminoa flatworms were not detected in photographs, though they were identified in situ. Estimates of black band disease and abnormally pigmented coral tissues were similar between the two methods. Estimates of the bleached and healthy colonies were also similar between methods and photographic analyses were a strong predictor of bleached (r 2 = 0.8) and healthy (r 2 = 0.5) colony prevalence from in situ surveys. Moreover, when data on disease and compromised health states resulting in white or pale coral colony appearance were pooled, the prevalence of 'white' colonies from in situ (14%) and photographic analyses (11%) were statistically similar. Our results indicate that information on coral disease and health collected by in situ surveys and photographic analyses are not directly comparable, with in situ surveys generally providing higher estimates of prevalence and greater ability to identify some diseases and compromised states. Careful sampling of photographs can however identify signs of coral stress, including some coral diseases, which may be used to trigger early-warning management interventions.

Dynamic response of a thin sessile drop of conductive liquid to an abruptly applied or removed electric field.

We consider, both theoretically and experimentally, a thin sessile drop of conductive liquid that rests on the lower plate of a parallel-plate capacitor. We derive analytical expressions for both the initial deformation and the relaxation dynamics of the drop as the electric field is either abruptly applied or abruptly removed, as functions of the geometrical, electrical, and material parameters, and investigate the ranges of validity of these expressions by comparison with full numerical simulations. These expressions provide a reasonable description of the experimentally measured dynamic response of a drop of conductive ionic liquid 1-butyl-3-methyl imidazolium tetrafluoroborate.

Penile intracavernosal pillars: lessons from anatomy and potential implications for penile prosthesis placement.

The objective of this study was to anatomically describe the relationship of penile intracavernosal pillars to penile surgery, specifically corporal dilation during penile prosthesis placement. Corpora cavernosa from four embalmed male cadavers were dissected and subjected to probe dilation. Corpora were cross-sectioned and examined for the gross presence and location of pillars and dilated spaces. Infrapubic penile prosthesis insertion was performed on one fresh-frozen cadaveric male pelvis, followed by cross-sectioning. A single patient had intracavernosal pillars examined intraoperatively during Peyronie's plaque excision and penile prosthesis insertion. Intracavernosal pillars were identified in all cadavers and one surgical patient, passing obliquely from the dorsolateral tunica albuginea across the sinusoidal space to the ventral intercorporal septum. This delineated each corpus into two potential compartments for dilation: dorsomedial and ventrolateral. Dorsal dilation seated instruments and prosthetics satisfactorily in the dorsal mid glans and provided additional tissue coverage over weak ventral areas of the tunica albuginea, while ventrolateral dilation appeared to result in ventral seating and susceptibility to perforation. Intracavernosal pillars are an important anatomic consideration during penile prosthesis placement. Dorsal dilation appears to result in improved distal seating of cylinder tips, which may be protective against tip malposition, perforation or subsequent erosion.

Quantitative diet analysis of four mesopredators from a coral reef.

The diets of four common mesopredator fishes were examined in the back-reef habitat of a subtropical fringing reef system during the summer months. Quantitative gut content analyses revealed that crustaceans, represented >60% of ingested prey (% mass) by the latticed sand-perch Parapercis clathrata, brown dottyback Pseudochromis fuscus and half-moon grouper Epinephelus rivulatus. Dietary analyses also provided insights into ontogenetic shifts. Juvenile P. fuscus ingested large numbers of crustaceans (amphipods and isopods); these small prey were rarely found in larger individuals (<1% of ingested mass). Fishes also made an important contribution to the diets of all three species representing 10-30% of ingested mass. Conversely, the sand lizardfish Synodus dermatogenys fed exclusively on fishes including clupeids, gobies and labrids. Differences in the gut contents of the four species recorded were not apparent using stable isotope analysis of muscle tissues. The similarity of δ(13) C values in muscle tissues suggested that carbon within prey was derived from primary producers, with comparable carbon isotope signatures to corals and macroalgae, whilst similarities in δ(15) N values indicated that all four species belonged to the same trophic level. Thus, interspecific differences between mesopredator diets were undetectable when using stable isotope analysis which suggests that detailed elucidation of trophic pathways requires gut content analyses.

Critical research needs for managing coral reef marine protected areas: perspectives of academics and managers.

Marine protected areas (MPAs) are a primary policy instrument for managing and protecting coral reefs. Successful MPAs ultimately depend on knowledge-based decision making, where scientific research is integrated into management actions. Fourteen coral reef MPA managers and sixteen academics from eleven research, state and federal government institutions each outlined at least five pertinent research needs for improving the management of MPAs situated in Australian coral reefs. From this list of 173 key questions, we asked members of each group to rank questions in order of urgency, redundancy and importance, which allowed us to explore the extent of perceptional mismatch and overlap among the two groups. Our results suggest the mismatch among MPA managers and academics is small, with no significant difference among the groups in terms of their respective research interests, or the type of questions they pose. However, managers prioritised spatial management and monitoring as research themes, whilst academics identified climate change, resilience, spatial management, fishing and connectivity as the most important topics. Ranking of the posed questions by the two groups was also similar, although managers were less confident about the achievability of the posed research questions and whether questions represented a knowledge gap. We conclude that improved collaboration and knowledge transfer among management and academic groups can be used to achieve similar objectives and enhance the knowledge-based management of MPAs.

Habitat degradation and fishing effects on the size structure of coral reef fish communities.

Overfishing and habitat degradation through climate change pose the greatest threats to sustainability of marine resources on coral reefs. We examined how changes in fishing pressure and benthic habitat composition influenced the size spectra of island-scale reef fish communities in Lau, Fiji. Between 2000 and 2006 fishing pressure declined in the Lau Islands due to declining human populations and reduced demand for fresh fish. At the same time, coral cover declined and fine-scale architectural complexity eroded due to coral bleaching and outbreaks of crown-of-thorns starfish, Acanthaster planci. We examined the size distribution of reef fish communities using size spectra analysis, the linearized relationship between abundance and body size class. Spatial variation in fishing pressure accounted for 31% of the variation in the slope of the size spectra in 2000, higher fishing pressure being associated with a steeper slope, which is indicative of fewer large-bodied fish and/or more small-bodied fish. Conversely, in 2006 spatial variation in habitat explained 53% of the variation in the size spectra slopes, and the relationship with fishing pressure was much weaker (approximately 12% of variation) than in 2000. Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish < 20 cm. Habitat degradation will compound effects of fishing on coral reefs as increased fishing reduces large-bodied target species, while habitat loss results in fewer small-bodied juveniles and prey that replenish stocks and provide dietary resources for predatory target species. Effective management of reef resources therefore depends on both reducing fishing pressure and maintaining processes that encourage rapid recovery of coral habitat.

Crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes.

Expert opinion was canvassed to identify crucial knowledge gaps in current understanding of climate change impacts on coral reef fishes. Scientists that had published three or more papers on the effects of climate and environmental factors on reef fishes were invited to submit five questions that, if addressed, would improve our understanding of climate change effects on coral reef fishes. Thirty-three scientists provided 155 questions, and 32 scientists scored these questions in terms of: (i) identifying a knowledge gap, (ii) achievability, (iii) applicability to a broad spectrum of species and reef habitats, and (iv) priority. Forty-two per cent of the questions related to habitat associations and community dynamics of fish, reflecting the established effects and immediate concern relating to climate-induced coral loss and habitat degradation. However, there were also questions on fish demographics, physiology, behaviour and management, all of which could be potentially affected by climate change. Irrespective of their individual expertise and background, scientists scored questions from different topics similarly, suggesting limited bias and recognition of a need for greater interdisciplinary and collaborative research. Presented here are the 53 highest-scoring unique questions. These questions should act as a guide for future research, providing a basis for better assessment and management of climate change impacts on coral reefs and associated fish communities.

Objective assessment of mobility of the spinal cord injured in a free-living environment.

STUDY DESIGN: An exploratory study of the practicality and feasibility of an instrument. OBJECTIVES: To adapt an activity monitor for use on a wheelchair to assess long-term mobility in a free-living environment in the spinal cord injury (SCI) population, and to explore the utility of the data collected. SETTING: Glasgow, UK. METHODS: An activity monitor was adapted for use on a wheelchair wheel. The monitor was used to assess, for 1 week, the wheelchair mobility of seven participants with SCI who only used a wheelchair. In conjunction with a second monitor on the thigh the mobility of seven participants with SCI who used a wheelchair and upright mobility, and five healthy non-wheelchair users, were assessed for 1 day. RESULTS: The adapted monitor collected 1260 h of data and was suitable for use on both manual and electric wheelchairs. During 1 week, participants with SCI who only used a wheelchair spent between 4 and 13 h moving in the wheelchair, covering a distance of between 7 and 28 km. Distinct differences in mobility were shown between participants with an SCI and non-wheelchair users. The differences in time spent in mobility activities between the groups of participants with SCI were smaller. CONCLUSIONS: The system was successfully used in this group of participants with SCI, and could provide useful information on the mobility of people with SCI in a free-living environment.

[Dysfunctions of artificial urinary sphincters (AMS 800) and their management via a transscrotal access. Optimum procedure illustrated by reference to clinical examples]. / Korrektur der Fehlfunktionen von artefiziellen Sphinkterimplantaten (AMS 800) über einen transskrotalen Zugang. Optimiertes Vorgehen anhand von Patientenbeispielen.

BACKGROUND: The introduction of a transscrotal access for implantation of an artificial urinary sphincter (AUS) offers an alternative to the perineal approach for dealing with post-prostatectomy incontinence. Should a revision be necessary, the entire implant can be explored via this access and only one incision is needed. The aim of our study was to present the advantage of the transscrotal approach in different malfunctions of AUSs (AMS 800). MATERIALS AND METHODS: Surgical exploration was exemplary indicated in three male patients because of recurrent incontinence after artificial sphincter implantation. The reasons for malfunction were urethral atrophy, a mechanical defect of the device, and urethral erosion of the cuff, which led to explantation via the perineal approach of the entire artificial sphincter system. The patient whose sphincter system had a mechanical defect had the entire system substituted by the transscrotal route. In the case of perineal explantation a complete new AMS 800 system was implanted transscrotally at the unaffected bulbar ureter following complete healing. In the case of urethral atrophy a tandem-cuff was implanted by a transscrotal approach. Because of mechanical complications the whole system was exchanged, a completely new AUS (AMS 800) system being implanted by the transscrotal approach after perineal explantation. RESULTS: There were no complications of any of the revision operations. The postoperative course was uneventful and after activation of the system all patients regained their former continence status. Three months after implantation all patients remained continent and their AMS 800 sphincter systems were fully functional. CONCLUSION: When a revision operation is needed, the transscrotal access offers a quick and easy alternative to the perineal method. Our patients had no postoperative complications, and their continence rates were satisfactory. Further studies are needed to reveal whether this approach will prove superior to the perineal approach in the long term.

Multi-institutional outcome study on the efficacy of closed-suction drainage of the scrotum in three-piece inflatable penile prosthesis surgery.

Infection is a devastating complication of penile prosthesis surgery that occurs in approximately 2-5% of all primary inflatable penile primary implants in most series. Prevention of hematoma and swelling with closed-suction drains has been shown not to increase infection rate and yield an earlier recovery time. Despite the intuitive advantages of short-term closed-suction drainage in reducing the incidence of postoperative scrotal swelling and associated adverse effects, many urologists are reluctant to drain the scrotum because of a theoretical risk of introducing an infection. In conclusion, this study was undertaken to evaluate the incidence of infection in three-piece penile prosthesis surgery with scrotal closed-suction drainage. A retrospective review of 425 consecutive primary three-piece penile prosthesis implantations was performed at three institutions in New Jersey, Ohio, and Arkansas from 1998 to 2002. Following the prosthesis insertion, 10 French Round Blake (Johnson & Johnson) or, in a few cases, 10 French Jackson Pratt, closed-suction drains were placed in each patient for less than 24 h. All subjects received standard perioperative antibiotic coverage. Average age at implant was 62 y (range 24-92 y). Operative time (incision to skin closure) was less than 60 min in the vast majority of cases. There were a total of 14 (3.3%) infections and three hematomas (0.7%) during an average 18-month follow-up period. In conclusion, this investigation revealed that closed-suction drainage of the scrotum for approximately 12-24 h following three-piece inflatable penile prosthesis surgery does not result in increased infection rate and is associated with a very low incidence of postoperative hematoma formation, swelling, and ecchymosis.

Ectopic placement of AMS 800 urinary control system pressure-regulating balloon.

OBJECTIVES: The AMS 800 sphincter urinary control system (artificial urinary sphincter) is frequently placed in patients with scarred retroperitoneal spaces. Placement of the pressure-regulating balloon (PRB) requires a second abdominal incision in the traditional perineal surgical technique. In the new transverse scrotal incision method of sphincter placement, the transversalis fascia is pierced to place the PRB in the space of Retzius. We present a novel technique of ectopic PRB placement requiring neither a second incision nor piercing the fascia. TECHNICAL CONSIDERATIONS: Nineteen patients underwent ectopic PRB placement during artificial urinary sphincter placement. Most patients (n = 17) were incontinent after radical prostatectomy, two were incontinent after transurethral resection of the prostate. Cuff placement was through a scrotal (n = 10) or perineal (n = 9) incision. In all patients, the incision was displaced toward either inguinal ring. A finger was passed through the ring forcibly cephalad and a space developed anterior to the transversalis fascia but beneath the abdominal muscles. The PRB was passed into this space. CONCLUSIONS: The results of our study have shown that ectopic placement is easier and quicker. The PRB is usually not palpable. Two PRB hernias into the upper scrotum were noted after vigorous coughing. Two patients developed urethral atrophy under the cuff at 3 and 5.5 years. No erosions, infections, or mechanical failures were noted. Early outcomes with ectopic PRB placement seemed similar to that of traditional locations.