Ventral and dorsal streams processing visual motion perception (FDG-PET study)

Background: Earlier functional imaging studies on visually induced self-motion perception (vection) disclosed a bilateral network of activations within primary and secondary visual cortex areas which was combined with signal decreases, i.e., deactivations, in multisensory vestibular cortex areas. This finding led to the concept of a reciprocal inhibitory interaction between the visual and vestibular systems. In order to define areas involved in special aspects of self-motion perception such as intensity and duration of the perceived circular vection (CV) or the amount of head tilt, correlation analyses of the regional cerebral glucose metabolism, rCGM (measured by fluorodeoxyglucose positron-emission tomography, FDG-PET) and these perceptual covariates were performed in 14 healthy volunteers. For analyses of the visual-vestibular interaction, the CV data were compared to a random dot motion stimulation condition (not inducing vection) and a control group at rest (no stimulation at all). Results: Group subtraction analyses showed that the visual-vestibular interaction was modified during CV, i.e., the activations within the cerebellar vermis and parieto-occipital areas were enhanced. The correlation analysis between the rCGM and the intensity of visually induced vection, experienced as body tilt, showed a relationship for areas of the multisensory vestibular cortical network (inferior parietal lobule bilaterally, anterior cingulate gyrus), the medial parieto-occipital cortex, the frontal eye fields and the cerebellar vermis. The "earlier" multisensory vestibular areas like the parieto-insular vestibular cortex and the superior temporal gyrus did not appear in the latter analysis. The duration of perceived vection after stimulus stop was positively correlated with rCGM in medial temporal lobe areas bilaterally, which included the (para-) hippocampus, known to be involved in various aspects of memory processing. The amount of head tilt was found to be positively correlated with the rCGM of bilateral basal ganglia regions responsible for the control of motor function of the head. Conclusions: Our data gave further insights into subfunctions within the complex cortical network involved in the processing of visual-vestibular interaction during CV. Specific areas of this cortical network could be attributed to the ventral stream ("what" pathway) responsible for the duration after stimulus stop and to the dorsal stream ("where/how" pathway) responsible for intensity aspects

Water extracts from Siberian thawing permafrost - from land to ocean

To better understand and quantify fluxes of dissolved elements upon permafrost thaw, water-soluble elements from Siberian permafrost samples covering a wide geographic range were determined by extraction. We measured the pH- and EC-values as well as the total dissolved major and secondary cation concentrations and anion concentrations for 270 water extracts from 12 different sites around the Laptev Sea. Cation concentrations were analyzed using inductively coupled plasma-optical emission spectrometry and anion concentrations by ion chromatography. Hydrogen carbonate concentrations were measured by potentiometric pH-value titration using an automatic titrator. Electrical conductivity and pH values were measured using a WTW MultiLab 540 multi-parameter device. As ground ice melts throughout Siberia with continued climate warming, drainage of the soils in many locations is improving and exposing mineral surfaces that were previously largely inert by their perennially frozen condition and unaffected by active weathering through seasonal wetting and drying cycles. Chemical analyses of water extracts allow an assessment of the potential interactions between mineral surfaces and pore melt water and the characteristics and biogeochemical and ecological consequences of the export of melt water from thawing permafrost. The (hydro-)chemical flux from permafrost sources into the riverine and marine realms is mainly defined by its source signatures and concentrations, which will be addressed in the present study. We compare our values with water data from lakes, rivers and the Arctic Ocean. The influence of terrestrial input from thawing permafrost including ground ice is expected to increase as coastal and river shore erosion as well as other permafrost degradation processes accelerate under Arctic warming and mobilize previously freeze-locked material. The increasing influx of dissolved elements influences transport and deposition processes in aquatic environments as well as nutrient supply, food chains and life cycles with largely understudied consequences for aquatic and coastal ecosystems in the Arctic

p53 and p16 expression profiles in vulvar cancer:a translational analysis by the Arbeitsgemeinschaft Gynäkologische Onkologie Chemo and Radiotherapy in Epithelial Vulvar Cancer study group

Background: There are 2 known pathways for tumorigenesis of vulvar squamous cell carcinoma—a human papillomavirus–dependent pathway characterized by p16 overexpression and a human papillomavirus–independent pathway linked to lichen sclerosus, characterized by TP53 mutation. A correlation of human papillomavirus dependency with a favorable prognosis has been proposed. Objective: The objective of the study was to further understand the role of human papillomavirus and p53 status in vulvar squamous cell carcinoma and characterize its clinical relevance. Study Design: The Arbeitsgemeinschaft Gynaecological Oncology Chemo and Radiotherapy in Epithelial Vulvar Cancer-1 study is a retrospective cohort study of 1618 patients with primary vulvar squamous cell carcinoma Fédération Internationale de Gynécologie et d'Obstétrique stage ≥1B treated at 29 gynecologic cancer centers in Germany between 1998 and 2008. For this translational substudy, formalin-fixed paraffin-embedded tissue was collected. A tissue microarray was constructed (n=652 samples); p16 and p53 expression was determined by immunohistochemistry. Human papillomavirus status and subtype were analyzed by polymerase chain reaction. Results: p16 immunohistochemistry was positive in 166 of 550 tumors (30.2%); p53 staining in 187 of 597 tumors (31.3%). Only tumors with available information regarding p16 and p53 immunohistochemistry and without p53 silent expression pattern were further analyzed (n=411); 3 groups were defined: p53+ (n=163), p16+/p53− (n=132), and p16−/p53− (n=116). Human papillomavirus DNA was detected in 85.6% of p16+/p53− tumors; human papillomavirus-16 was the most common subtype (86.3%). Patients with p16+ tumors were younger (64 vs 72 years for p53+, respectively, 69 years for p16−/p53− tumors; P<.0001) and showed lower rates of lymph-node involvement (28.0% vs 42.3% for p53+, respectively, 30.2% for p16−/p53− tumors; P=.050). Notably, 2-year-disease-free and overall survival rates were significantly different among the groups: disease-free survival, 47.1% (p53+), 60.2% (p16−/p53−), and 63.9% (p16+/p53−) (P<.001); overall survival, 70.4% (p53+), 75.4% (p16−/p53−), and 82.5% (p16+/p53−) (P=.002). In multivariate analysis, the p16+/p53− phenotype showed a consistently improved prognosis compared with the other groups (hazard ratio, 0.66; 95% confidence interval, 0.44–0.99; P=.042). Conclusion: p16 overexpression is associated with an improved prognosis whereas p53 positivity is linked to an adverse outcome. Our data support the hypothesis of a clinically relevant third subgroup of vulvar squamous cell carcinoma with a p53−/p16− phenotype showing an intermediate prognosis that needs to be further characterized

Role of Pelvic Lymph Node Resection in Vulvar Squamous Cell Cancer:A Subset Analysis of the AGO-CaRE-1 Study

Background: As the population at risk for pelvic nodal involvement remains poorly described, the role of pelvic lymphadenectomy (LAE) in vulvar squamous cell cancer (VSCC) has been a matter of discussion for decades. Methods: In the AGO-CaRE-1 study, 1618 patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB or higher primary VSCC treated at 29 centers in Germany between 1998 and 2008 were documented. In this analysis, only patients with pelvic LAE (n = 70) were analyzed with regard to prognosis and correlation between inguinal and pelvic lymph node involvement. Results: The majority of patients had T1b/T2 tumors (n = 47; 67.1%), with a median diameter of 40 mm (2–240 mm); 54/70 patients (77.1%) who received pelvic LAE had positive groin nodes. For 42 of these 54 patients, the number of affected groin nodes had been documented as a median of 3; 14/42 (33.3%) of these patients had histologically confirmed pelvic nodal metastases (median number of affected pelvic nodes 3 [1–12]). In these 14 patients, the median number of affected groin nodes was 7 (1–30), with a groin metastases median maximum diameter of 42.5 mm (12–50). Receiver operating characteristic analysis showed an area under the curve of 0.85, with 83.3% sensitivity and 92.6% specificity for the prediction of pelvic involvement in cases of six or more positive groin nodes. No cases of pelvic nodal involvement without groin metastases were observed. Prognosis in cases of pelvic metastasis was poor, with a median progression-free survival of only 12.5 months. Conclusion: For the majority of node-positive patients with VSCC, pelvic nodal staging appears unnecessary since a relevant risk for pelvic nodal involvement only seems to be present in highly node-positive disease

Adjuvant radiotherapy and local recurrence in vulvar cancer:a subset analysis of the AGO-CaRE-1 study

Background: The impact of adjuvant radiotherapy (RT) to the vulva with regard to prognosis and local recurrence in patients with vulvar squamous cell cancer (VSCC) is poorly described. Patients and methods: In the AGO-CaRE-1 study 1618 patients with primary VSCC FIGO stage ≥ IB, treated between 1998-2008, were documented. In this retrospective subanalysis, 360 patients were included based on the following criteria: nodal involvement (pN+), known RT treatment and known radiation fields. Results: The majority had pT1b/pT2 tumors (n=299; 83.1%). In 76.7%, R0 resection was achieved. 57/360 (15.8%) N+ patients were treated with adjuvant RT to the groins/pelvis and 146/360 (40.5%) received adjuvant RT to the vulva and groins/pelvis. 157/360 (43.6%) patients did not receive any adjuvant RT. HPV status was available in 162/360 patients (45.0%), 75/162 tumors were HPV+(46.3%), 87/162 (53.7%) HPV-. During a median follow-up of 17.2 months, recurrence at the vulva only occurred in 25.5% of patients without adjuvant RT, in 22.8% of patients with adjuvant RT to groins/pelvis and in 15.8% of patients with adjuvant RT to the vulva and groins/pelvis respectively. The risk reducing effect of local RT was independent of the resection margin status. 50% disease free survival time (50% DFST) indicated a stronger impact of adjuvant RT to the vulva in HPV+ compared to HPV- patients (50% DFST 20.7 months vs. 17.8 months). Conclusion: Adjuvant RT to the vulva was associated with a lower risk for local recurrence in N+ VSCC independent of the resection margin status. This observation was more pronounced in patients with HPV+ tumors in comparison to HPV– tumors

Role of Pelvic Lymph Node Resection in Vulvar Squamous Cell Cancer: A Subset Analysis of the AGO-CaRE-1 Study

Abstract Background As the population at risk for pelvic nodal involvement remains poorly described, the role of pelvic lymphadenectomy (LAE) in vulvar squamous cell cancer (VSCC) has been a matter of discussion for decades. Methods In the AGO-CaRE-1 study, 1618 patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB or higher primary VSCC treated at 29 centers in Germany between 1998 and 2008 were documented. In this analysis, only patients with pelvic LAE (n = 70) were analyzed with regard to prognosis and correlation between inguinal and pelvic lymph node involvement. Results The majority of patients had T1b/T2 tumors (n = 47; 67.1%), with a median diameter of 40 mm (2–240 mm); 54/70 patients (77.1%) who received pelvic LAE had positive groin nodes. For 42 of these 54 patients, the number of affected groin nodes had been documented as a median of 3; 14/42 (33.3%) of these patients had histologically confirmed pelvic nodal metastases (median number of affected pelvic nodes 3 [1–12]). In these 14 patients, the median number of affected groin nodes was 7 (1–30), with a groin metastases median maximum diameter of 42.5 mm (12–50). Receiver operating characteristic analysis showed an area under the curve of 0.85, with 83.3% sensitivity and 92.6% specificity for the prediction of pelvic involvement in cases of six or more positive groin nodes. No cases of pelvic nodal involvement without groin metastases were observed. Prognosis in cases of pelvic metastasis was poor, with a median progression-free survival of only 12.5 months. Conclusion For the majority of node-positive patients with VSCC, pelvic nodal staging appears unnecessary since a relevant risk for pelvic nodal involvement only seems to be present in highly node-positive disease

Ventral and dorsal streams processing visual motion perception (FDG-PET study)

Background: Earlier functional imaging studies on visually induced self-motion perception (vection) disclosed a bilateral network of activations within primary and secondary visual cortex areas which was combined with signal decreases, i.e., deactivations, in multisensory vestibular cortex areas. This finding led to the concept of a reciprocal inhibitory interaction between the visual and vestibular systems. In order to define areas involved in special aspects of self-motion perception such as intensity and duration of the perceived circular vection (CV) or the amount of head tilt, correlation analyses of the regional cerebral glucose metabolism, rCGM (measured by fluorodeoxyglucose positron-emission tomography, FDG-PET) and these perceptual covariates were performed in 14 healthy volunteers. For analyses of the visual-vestibular interaction, the CV data were compared to a random dot motion stimulation condition (not inducing vection) and a control group at rest (no stimulation at all). Results: Group subtraction analyses showed that the visual-vestibular interaction was modified during CV, i.e., the activations within the cerebellar vermis and parieto-occipital areas were enhanced. The correlation analysis between the rCGM and the intensity of visually induced vection, experienced as body tilt, showed a relationship for areas of the multisensory vestibular cortical network (inferior parietal lobule bilaterally, anterior cingulate gyrus), the medial parieto-occipital cortex, the frontal eye fields and the cerebellar vermis. The "earlier" multisensory vestibular areas like the parieto-insular vestibular cortex and the superior temporal gyrus did not appear in the latter analysis. The duration of perceived vection after stimulus stop was positively correlated with rCGM in medial temporal lobe areas bilaterally, which included the (para-) hippocampus, known to be involved in various aspects of memory processing. The amount of head tilt was found to be positively correlated with the rCGM of bilateral basal ganglia regions responsible for the control of motor function of the head. Conclusions: Our data gave further insights into subfunctions within the complex cortical network involved in the processing of visual-vestibular interaction during CV. Specific areas of this cortical network could be attributed to the ventral stream ("what" pathway) responsible for the duration after stimulus stop and to the dorsal stream ("where/how" pathway) responsible for intensity aspects

Australia-China relations is more than just government

With official relations at a new low, it is easy to be pessimistic about Australia-China relations. But there are many actors involved in Australia-China diplomacy. These connections can help provide communication channels for when official relations are frosty. They also bring economic, educational and cultural benefits

Fabrication approaches of dielectric elastomer stack transducers for complex and large-scale production

During the last years a lot of fabrication methods for dielectric elastomer stack transducers (DEST) have been developed. Existing methods are based on two-dimensional thin-film manufacturing technologies. Many applications with simple shaped DEST have been shown in the past but especially for prototyping three-dimensional structuring would allow individually suited modules for each application. Additionally, due to slow manufacturing and less quantities, available DEST are very expensive and that makes them futile for many applications at this time. In this work, two fabrication approaches are presented introducing three-dimensional structured DEST and an opportunity for large-scale production. First approach is based on a three-axis positioning system to deposit materials with a dual extruder on a heated build plate. By repetitive deposition of liquid electrode and elastomer materials printing of three-dimensional DEST with less than 50 µm layer thickness is feasible. Furthermore, it allows the integration of electrical connections, cavities, channels, sensors and other structural elements during the fabrication. In the second approach, an industrial slit die coater is used to deposit liquid materials onto a PET substrate. The setup is able to stack up to nine liquid layers consisting of different materials at the same time. Afterwards, all layers are dried and cross-linked in an oven. This allows large-scale production of DEST with up to four active layers