The role of grass volatiles on oviposition site selection by Anopheles arabiensis and Anopheles coluzzii

Background: The reproductive success and population dynamics, of Anopheles malaria mosquitoes is strongly influenced by the oviposition site selection of gravid females. Mosquitoes select oviposition sites at different spatial scales, starting with selecting a habitat in which to search. This study utilizes the association of larval abundance in the field with natural breeding habitats, dominated by various types of wild grasses, as a proxy for oviposition site selection by gravid mosquitoes. Moreover, the role of olfactory cues emanating from these habitats in the attraction and oviposition stimulation of females was analysed. Methods: The density of Anopheles larvae in breeding sites associated with Echinochloa pyramidalis, Echinochloa stagnina, Typha latifolia and Cyperus papyrus, was sampled and the larvae identified to species level. Headspace volatile extracts of the grasses were collected and used to assess behavioural attraction and oviposition stimulation of gravid Anopheles arabiensis and Anopheles coluzzii mosquitoes in wind tunnel and two-choice oviposition assays, respectively. The ability of the mosquitoes to differentiate among the grass volatile extracts was tested in multi-choice tent assays. Results: Anopheles arabiensis larvae were the most abundant species found in the various grass-associated habitats. The larval densities described a hierarchical distribution, with Poaceae (Echinochloa pyramidalis and Echinochloa stagnina)-associated habitat sites demonstrating higher densities than that of Typha-associated sites, and where larvae were absent from Cyperus-associated sites. This hierarchy was maintained by gravid An. arabiensis and An. coluzzii mosquitoes in attraction, oviposition and multi-choice assays to grass volatile extracts. Conclusions: The demonstrated hierarchical preference of gravid An. coluzzii and An. arabiensis for grass volatiles indicates that vegetation cues associated with larval habitats are instrumental in the oviposition site choice of the malaria mosquitoes. Identifying volatile cues from grasses that modulate gravid malaria mosquito behaviours has distinct potential for the development of tools to be used in future monitoring and control methods

Effects of Mountain Pine Beetle on Fuels and Expected Fire Behavior in Lodgepole Pine Forests, Colorado, USA

In Colorado and southern Wyoming, mountain pine beetle (MPB) has affected over 1.6 million ha of predominantly lodgepole pine forests, raising concerns about effects of MPB-caused mortality on subsequent wildfire risk and behavior. Using empirical data we modeled potential fire behavior across a gradient of wind speeds and moisture scenarios in Green stands compared three stages since MPB attack (Red [1–3 yrs], Grey [4–10 yrs], and Old-MPB [∼30 yrs]). MPB killed 50% of the trees and 70% of the basal area in Red and Grey stages. Across moisture scenarios, canopy fuel moisture was one-third lower in Red and Grey stages compared to the Green stage, making active crown fire possible at lower wind speeds and less extreme moisture conditions. More-open canopies and high loads of large surface fuels due to treefall in Grey and Old-MPB stages significantly increased surface fireline intensities, facilitating active crown fire at lower wind speeds (>30–55 km/hr) across all moisture scenarios. Not accounting for low foliar moistures in Red and Grey stages, and large surface fuels in Grey and Old-MPB stages, underestimates the occurrence of active crown fire. Under extreme burning conditions, minimum wind speeds for active crown fire were 25–35 km/hr lower for Red, Grey and Old-MPB stands compared to Green. However, if transition to crown fire occurs (outside the stand, or within the stand via ladder fuels or wind gusts >65 km/hr), active crown fire would be sustained at similar wind speeds, suggesting observed fire behavior may not be qualitatively different among MPB stages under extreme burning conditions. Overall, the risk (probability) of active crown fire appears elevated in MPB-affected stands, but the predominant fire hazard (crown fire) is similar across MPB stages and is characteristic of lodgepole pine forests where extremely dry, gusty weather conditions are key factors in determining fire behavior

The impact of chemotherapy on cognitive outcomes in adults with primary brain tumors

There is growing recognition that chemotherapy may have short and long term impact on cognitive function of cancer patients. However, the impact of chemotherapy on the cognition of adult patients with primary brain tumor has not been extensively studied. This article will review the evidence for both positive and negative impact of chemotherapy on cognitive function of adult brain tumor patients as well as potential confounding factors

Repair of isthmic pars interarticularis fractures: a literature review of conventional and minimally invasive techniques

The repair of symptomatic isthmic pars interarticularis fractures can result in excellent outcomes. A variety of operative interventions exist with conventional techniques requiring larger exposures. Recently described, less invasive techniques tend to minimize disruption of adjacent soft tissues, decrease postoperative pain, increase patient satisfaction, and improve return to work status and/or competitive sports. The present review details both conventional and minimally invasive techniques of pars interarticularis repairs. Also, the review uniquely describes the authors' technique of fluoroscopically guided direct pars screw placement with recombinant human morphogenic protein, with clinical and radiographic outcomes. A PubMed database literature review and retrospective chart review were conducted, in search of patients with lumbar spondylosis treated surgically. Literature review focused on various surgical techniques in repairing pars interarticularis fractures. Retrospective chart review analyzed demographic, radiographic, as well as pre- and postoperative clinical outcomes data. Surgical technique was characterized as traditional or minimally invasive operative technique. Four major operative techniques are discussed: The Buck repair, the Scott repair, the Morscher repair, and other pedicle-screw based repairs. The Levi technique is also described, utilizing minimally invasive techniques, in full. Surgical treatment of isthmic pars interarticularis fractures is safe and effective. Many surgical techniques exist, however minimally invasive techniques tend to provide additional clinical benefit. Moreover, fluoroscopically guided direct pars screw placement with use of recombinant human morphogenic protein, may provide the most benefit, especially in adolescent patients with high levels of physical activity

Treatment of a persistent iatrogenic cerebrospinal fluid-pleural fistula with a cadaveric dural-pleural graft

A cerebrospinal fluid (CSF)-pleural fistula is a unique condition with which all spine surgeons need to be familiar, particularly those who use anterolateral approaches to the thoracic region. When direct suturing of the dural defect is not possible, techniques for indirect repair must be considered. To report a novel technique for repair of a thoracic CSF-pleural fistula with a cadaveric dural-pleural graft after failure of initial treatment with Duragen (Integra, Plainsboro, NJ) and fibrin glue. Case report/University of Miami/Jackson Memorial Medical Center. The case of a 65-year-old female is presented. The patient represented 5 weeks after the initial operation (left-sided thoracotomy, partial T10–T11 corpectomy and removal of an intradural calcified disc) with dyspnea and severe positional headaches. Imaging of the brain revealed a subdural hematoma and magnetic resonance imaging of the thoracic region demonstrated a pseudomeningocele surrounding the postsurgical bed. She underwent a revision thoracotomy and CSF-pleural fistula repair. We addressed the dural opening indirectly by suturing a piece of cadaveric dural allograft to the thickened pleura, after Duragen and fibrin glue were placed over the dural defect. A lumbar drain and a chest tube were also placed. At 12 weeks post-op, the subdural hematoma had completely resolved and her chest X-rays demonstrated a significant decrease in the CSF-pleural collection. Anterolateral thoracic disc surgery poses a great challenge to the spine surgeon but can provide the most direct way of decompressing the spinal cord as a result of ventral pathology. Some of the most difficult aspects of dealing with a CSF leak in this area relates to 1) the relative complexity of suturing the dura directly as it is at a considerable distance from the operating surgeon; 2) the manner in which the contralateral dura slopes away and is hidden from view; and 3) the relatively negative intrathoracic pressure, which encourages the persistent flow of CSF from the intradural to the pleural cavity. We speculate that with open thoracic surgery and the creation of a large potential space with an open dural defect, this technique provided an additional barrier against the formation of a CSF-pleural fistula. Using this technique, we intentionally create a pseudomeningocele into the corpectomy defect that is contained within the confines of our dural-pleural graft

366 - Spinal Osteotomies

Osteotomies of the spinal column are powerful corrective measures used to treat various forms of spinal deformity. Spinal osteotomies are procedures that remove specific bony structures in order to surgically correct a structural deformity of the spine. Until recently, there has been considerable variation in the description of and surgical technique for each osteotomy type. With the advent of an anatomic spinal osteotomy classification system, surgeons are better equipped to perform, and communicate, osteotomy procedures. The objective of this chapter is to review nomenclature and relevant details of an anatomically driven spinal osteotomy classification system. The system is compared to previous and current eponyms and alternative language. Operative technique and key perioperative issues are discussed. In this grading system, each osteotomy grade increases in bony resection, corrective power, and perioperative morbidity. The corresponding eponyms and alternative names are categorized accordingly. With further use, the anatomic classification system will provide further consistency among surgeons and within the literature

A Calpain Inhibitor Enhances the Survival of Schwann Cells In Vitro and after Transplantation into the Injured Spinal Cord

Despite the diversity of cells available for transplantation into sites of spinal cord injury (SCI), and the known ability of transplanted cells to integrate into host tissue, functional improvement associated with cellular transplantation has been limited. One factor potentially limiting the efficacy of transplanted cells is poor cell survival. Recently we demonstrated rapid and early death of Schwann cells (SCs) within the first 24 h after transplantation, by both necrosis and apoptosis, which results in fewer than 20% of the cells surviving beyond 1 week. To enhance SC transplant survival, in vitro and in vivo models to rapidly screen compounds for their ability to promote SC survival are needed. The current study utilized in vitro models of apoptosis and necrosis, and based on withdrawal of serum and mitogens and the application of hydrogen peroxide, we screened several inhibitors of apoptosis and necrosis. Of the compounds tested, the calpain inhibitor MDL28170 enhanced SC survival both in vitro in response to oxidative stress induced by application of H 2 O 2 , and in vivo following delayed transplantation into the moderately contused spinal cord. The results support the use of calpain inhibitors as a promising new treatment for promoting the survival of transplanted cells. They also suggest that in vitro assays for cell survival may be useful for establishing new compounds that can then be tested in vivo for their ability to promote transplanted SC survival

Use of a contoured bioresorbable plate with a hemostatic plug to control life-threatening bleeding from the superior sagittal sinus during hemispherotomy: technical note

Profuse bleeding originating from an injured cerebral sinus can be a harrowing experience for any surgeon, particularly during an operation on a young child. Common surgical remedies include sinus ligation, primary repair, placement of a hemostatic plug, and patch or venous grafting that may require temporary stenting. In this paper the authors describe the use of a contoured bioresorbable plate to hold a hemostatic plug in place along a tear in the inferomedial portion of a relatively inaccessible part of the posterior segment of the superior sagittal sinus in an 11-kg infant undergoing hemispherotomy for epilepsy. This variation on previously described hemostatic techniques proved to be easy, effective, and ultimately lifesaving. Surgeons may find this technique useful in similar dire circumstances when previously described techniques are ineffective or impractical