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Background: It is well recognized that the molar activity of a radioligand is an important pharmacokinetic parameter, especially in positron emission tomography (PET) of small animals. Occupation of a significant number of binding sites by radioligand molecules results in low radioligand accumulation in a target region (mass effect). Nevertheless, small-animal PET studies have often been performed without consideration of the molar activity or molar dose of radioligands. A simulation study would therefore help to assess the importance of the mass effect in small-animal PET. Here, we introduce a new compartmental model-based numerical method, which runs on commonly used spreadsheet software, to simulate the effect of molar activity or molar dose on the pharmacokinetics of radioligands. Results: Assuming a two-tissue compartmental model, time-concentration curves of a radioligand were generated using four simulation methods and the well-known Runge–Kutta numerical method. The values were compared with theoretical values obtained under an ultra-high molar activity condition (pseudo-first-order binding kinetics), a steady-state condition and an equilibrium condition (second-order binding kinetics). For all conditions, the simulation method using the simplest calculation yielded values closest to the theoretical values and comparable with those obtained using the Runge–Kutta method. To satisfy a maximum occupancy less than 5%, simulations showed that a molar activity greater than 150 GBq/μmol is required for a model radioligand when 20 MBq is administered to a 250 g rat and when the concentration of binding sites in target regions is greater than 1.25 nM. Conclusions: The simulation method used in this study is based on a very simple calculation and runs on widely used spreadsheet software. Therefore, simulation of radioligand pharmacokinetics using this method can be performed on a personal computer and help to assess the importance of the mass effect in small-animal PET. This simulation method also enables the generation of a model time-activity curve for the evaluation of kinetic analysis methods. [ABSTRACT FROM AUTHOR]

Abstract Background It is well recognized that the molar activity of a radioligand is an important pharmacokinetic parameter, especially in positron emission tomography (PET) of small animals. Occupation of a significant number of binding sites by radioligand molecules results in low radioligand accumulation in a target region (mass effect). Nevertheless, small-animal PET studies have often been performed without consideration of the molar activity or molar dose of radioligands. A simulation study would therefore help to assess the importance of the mass effect in small-animal PET. Here, we introduce a new compartmental model-based numerical method, which runs on commonly used spreadsheet software, to simulate the effect of molar activity or molar dose on the pharmacokinetics of radioligands. Results Assuming a two-tissue compartmental model, time-concentration curves of a radioligand were generated using four simulation methods and the well-known Runge–Kutta numerical method. The values were compared with theoretical values obtained under an ultra-high molar activity condition (pseudo-first-order binding kinetics), a steady-state condition and an equilibrium condition (second-order binding kinetics). For all conditions, the simulation method using the simplest calculation yielded values closest to the theoretical values and comparable with those obtained using the Runge–Kutta method. To satisfy a maximum occupancy less than 5%, simulations showed that a molar activity greater than 150 GBq/μmol is required for a model radioligand when 20 MBq is administered to a 250 g rat and when the concentration of binding sites in target regions is greater than 1.25 nM. Conclusions The simulation method used in this study is based on a very simple calculation and runs on widely used spreadsheet software. Therefore, simulation of radioligand pharmacokinetics using this method can be performed on a personal computer and help to assess the importance of the mass effect in small-animal PET. This simulation method also enables the generation of a model time-activity curve for the evaluation of kinetic analysis methods.

Oncocytoma arising from the parotid gland and extending into the parapharyngeal space (PPS) has not been previously reported. A 64-year-old woman presented with a large slowly growing mass extending from the parotid to the submandibular area, expanding medially to displace the pharynx across the midline. Core-needle biopsy revealed an oncocytoma in the PPS measuring 120 × 88 × 60 mm in size. Although the tumor was of an unprecedentedly large size and extended into multiple spaces, it could be removed via a cervical–parotid approach without osteotomy. The resected tumor was again diagnosed as oncocytoma. A postoperative complication was weakness of the ipsilateral facial nerve, which almost completely resolved in 6 months. No recurrence has been noted on 1 y follow-up. We were able to resect an extremely large oncocytoma arising from the parotid gland without osteotomy. [ABSTRACT FROM AUTHOR]

Background: Intracranial space is divided into three compartments by the falx cerebri and tentorium cerebelli. We assessed whether cerebrospinal fluid (CSF) distribution evaluated by a specifically developed deep-learning neural network (DLNN) could assist in quantifying mass effect. Methods: Head trauma CT scans from a high-volume emergency department between 2018 and 2020 were retrospectively analyzed. Manual segmentations of intracranial compartments and CSF served as the ground truth to develop a DLNN model to automate the segmentation process. Dice Similarity Coefficient (DSC) was used to evaluate the segmentation performance. Supratentorial CSF Ratio was calculated by dividing the volume of CSF on the side with reduced CSF reserve by the volume of CSF on the opposite side. Results: Two hundred and seventy-four patients (mean age, 61 years ± 18.6) after traumatic brain injury (TBI) who had an emergency head CT scan were included. The average DSC for training and validation datasets were respectively: 0.782 and 0.765. Lower DSC were observed in the segmentation of CSF, respectively 0.589, 0.615, and 0.572 for the right supratentorial, left supratentorial, and infratentorial CSF regions in the training dataset, and slightly lower values in the validation dataset, respectively 0.567, 0.574, and 0.556. Twenty-two patients (8%) had midline shift exceeding 5 mm, and 24 (8.8%) presented with high/mixed density lesion exceeding >25 ml. Fifty-five patients (20.1%) exhibited mass effect requiring neurosurgical treatment. They had lower supratentorial CSF volume and lower Supratentorial CSF Ratio (both p < 0.001). A Supratentorial CSF Ratio below 60% had a sensitivity of 74.5% and specificity of 87.7% (AUC 0.88, 95%CI 0.82-0.94) in identifying patients that require neurosurgical treatment for mass effect. On the other hand, patients with CSF constituting 10-20% of the intracranial space, with 80-90% of CSF specifically in the supratentorial compartment, and whose Supratentorial CSF Ratio exceeded 80% had minimal risk. Conclusion: CSF distribution may be presented as quantifiable ratios that help to predict surgery in patients after TBI. Automated segmentation of intracranial compartments using the DLNN model demonstrates a potential of artificial intelligence in quantifying mass effect. Further validation of the described method is necessary to confirm its efficacy in triaging patients and identifying those who require neurosurgical treatment. [ABSTRACT FROM AUTHOR]

Dispersal is more intense in the ocean than on land because most marine taxa present planktonic life stages that are transported by currents even without specific morphological traits. Thus, species dispersal shapes the distribution of biodiversity along seascapes and drives the composition of biodiversity assemblages. To identify marine assembling zones which characterise spatial areas particularly prone to receive and retain similar animal assemblages from the regional pool of species through passive dispersal, we propose a community‐based approach grounded on Lagrangian simulations of plankton dispersal. This novel approach was applied to communities (coast, outer shelf, slope, seamounts and islands; 0–80 m depth) of the Tropical Southwestern Atlantic and used to assess connectivity pathways. For that, we classified the modelled particles in 15 categories according to biological traits (planktonic life duration and spawning habitat) of representative planktonic communities. From the hierarchical clustering of the multivariate matrix containing the amount of arriving particles from each category in each cell we defined 14 assembling zones. Results highlighted that the assembling zones were mostly shaped by the degree of exposure to currents and the presence of mesoscale features (eddies, recirculation) derived from the interaction between these currents and coastlines. The boundaries, dispersal and connectivity patterns of these zones consistently align with local and regional in situ spatial distribution and abundance patterns of organisms, and provide an appropriate basis for the formulation of ecological hypotheses in the metacommunity framework to be tested in situ, such as the balance between species sorting and mass effect assembling archetypes. This approach, when coupled with the knowledge of other processes shaping communities' structure and distribution, provides important insights for regions and animal groups for which knowledge is limited or absent, and more generally allows for a comprehensive overview of the distribution of distinct communities and connectivity pathways along marine environments. [ABSTRACT FROM AUTHOR]

Abstract: Aim Our goal was to relate the phytoplankton metacommunity to its possible determinants in a micro watershed: (I) determinants related to landscape-scale filtering, (II) determinants referring to local microhabitat filtering, (III) determinants referring to previous colonization, and (IV) determinants representing three different dispersal routes. Methods Eight sampling stations were selected along the Cascavel River watershed, located in the state of Paraná, Brazil. Samples were collected quarterly for three years. All phytoplankton samples were quantitatively analyzed to determine the density of the metacommunity. In addition, it was characterized the landscape in terms of land use and occupation, and environmental characterization in terms of physical and chemical variables of the water. All data underwent relevant statistical analysis, where variance partitioning was carried out using partial RDA models, with prior selection of predictor variables, to estimate the relative role of each predictor in the community. We also compared three possible dispersal routes: “Asymmetric Eigenvector Map” (AEM), “Overland” and “Watercourse”. Results It was found that the metacommunity was best explained by “asymmetric eigenvector mapping” (AEM), indicating that because it is a small spatial scale the high connectivity between the sampling stations enables species to disperse overland as well. The different filters act together and depend on rainfall variation. Besides fluctuating temporally, the influence of these mechanisms is subject to which dispersal hypothesis is being considered. Conclusions At the watershed scale, we argue that small-scale processes should be considered, since they homogenize the landscape and consequently leave the environmental gradient similar between sampling stations. In addition, the connectivity of colonization patches is essential to understand the behavior of microalgae that have a high dispersal capacity and are not restricted only to the river course.

BackgroundIntracranial space is divided into three compartments by the falx cerebri and tentorium cerebelli. We assessed whether cerebrospinal fluid (CSF) distribution evaluated by a specifically developed deep-learning neural network (DLNN) could assist in quantifying mass effect.MethodsHead trauma CT scans from a high-volume emergency department between 2018 and 2020 were retrospectively analyzed. Manual segmentations of intracranial compartments and CSF served as the ground truth to develop a DLNN model to automate the segmentation process. Dice Similarity Coefficient (DSC) was used to evaluate the segmentation performance. Supratentorial CSF Ratio was calculated by dividing the volume of CSF on the side with reduced CSF reserve by the volume of CSF on the opposite side.ResultsTwo hundred and seventy-four patients (mean age, 61 years ± 18.6) after traumatic brain injury (TBI) who had an emergency head CT scan were included. The average DSC for training and validation datasets were respectively: 0.782 and 0.765. Lower DSC were observed in the segmentation of CSF, respectively 0.589, 0.615, and 0.572 for the right supratentorial, left supratentorial, and infratentorial CSF regions in the training dataset, and slightly lower values in the validation dataset, respectively 0.567, 0.574, and 0.556. Twenty-two patients (8%) had midline shift exceeding 5 mm, and 24 (8.8%) presented with high/mixed density lesion exceeding >25 ml. Fifty-five patients (20.1%) exhibited mass effect requiring neurosurgical treatment. They had lower supratentorial CSF volume and lower Supratentorial CSF Ratio (both p

An 84-year-old male with previously documented poor medical follow-up presented with progressive painless proptosis of the right eye. Right upper eyelid ptosis, limited motility, proptosis, and inferomedial displacement of the right globe were noted on the exam. Computed tomography (CT) imaging revealed a right retrobulbar extraconal heterogenous mass with ill-defined borders. Biopsy revealed a malignant adenocarcinoma with tumor markers suggestive of a colorectal primary. A rectal mass was identified during a systemic workup. After biopsy, the patient was diagnosed with stage IV metastatic rectal adenocarcinoma. He began palliative radiation therapy shortly following diagnosis.

Dispersal is a main determinant of community assembly. Landscape configurations of rivers, lakes, or ponds are often independently considered in this framework. However, these systems share species conforming to a waterscape with different environments coupled by dispersal. While empirical results support a main role of this coupling on biodiversity organization, it is difficult to assess its importance at large geographic scales. Using a theoretical approach, we quantified the potential role of dispersal through different freshwater ecosystems of the United Kingdom and Ireland on biogeographic diversity patterns. We implemented a coalescent model considering 11,131 communities connected by distance-dependent dispersal and with species that have different performances for recruitment in three different aquatic habitats. Biogeographic diversity patterns were estimated for each habitat alone or for the whole waterscape combining ephemeral, temporal, and permanent waters. The results indicated that the coupling between different types of environments fostered local diversity, in a magnitude that increased from the ephemeral to permanent waters and from poorer to richer communities. Furthermore, a strong spatial structure in the potential effect of dispersal among different freshwater environments was observed, indicating that freshwater biogeography was likely determined by the connection among freshwater ecosystems to a larger extent than previously thought. [ABSTRACT FROM AUTHOR]

Background and Objectives: Giant bullae rupture easily and cause tension pneumothorax, which can cause problems during general anesthesia. However, the hemodynamic instability that can occur due to the mass effect of an unruptured giant bulla should not be overlooked. Case report: A 43-year-old male patient visited the emergency room with an abdominal wound. There was a giant emphysematous bulla in the left lung. Emergency surgery was decided upon because there was active bleeding according to abdominal CT. After tracheal intubation, the patient's blood pressure and pulse rate dramatically decreased. His blood pressure did not recover despite the use of vasopressors and discontinuation of positive pressure ventilation applied to the lungs. Thus, a bullectomy was immediately performed. The patient's blood pressure and pulse rate were normalized after the bullectomy. Conclusions: If emergency surgery under general anesthesia is required in a patient with a giant emphysematous bulla, it is safe to minimize positive pressure ventilation and remove the giant emphysematous bulla as soon as possible before proceeding with the remainder of the surgery. Tension pneumothorax due to the rupturing of a bulla should be considered first. However, hemodynamic changes might occur due to the mass effect caused by a giant bulla. [ABSTRACT FROM AUTHOR]

Introduction: Splanchnic arterial aneurysms are a rare but potentially lethal disease with a mortality rate of more than 10% after rupture. Endovascular therapy is the first-line treatment for splanchnic aneurysms. However, appropriate management for splanchnic aneurysms after failed endovascular therapy remained inconclusive. Materials and methods: A retrospective review was performed for consecutive patients (from 2019 to 2022) who underwent salvage surgeries for splanchnic artery aneurysms following failed endovascular therapy. The authors defined failed endovascular therapy as the technical infeasibility to apply endovascular therapy, the incomplete exclusion of the aneurysm, or the incomplete resolution of preoperative aneurysm-associated complications. Salvage operations included aneurysmectomy with vascular reconstruction and partial aneurysmectomy with directly closing of bleeders from the intraluminal space of the aneurysms. Results: Seventy-three patients received endovascular therapies for splanchnic aneurysms, and 13 failed endovascular trials. The authors performed salvage surgeries for five patients and enrolled them in this study, including four false aneurysms of the celiac or superior mesenteric arteries and a true aneurysm of the common hepatic artery. The causes of failed endovascular therapy included coil migration, insufficient space for safely deploying the covered stent, a persistent mass effect from the postembolized aneurysm, or infeasibility for catheter cannulation. The mean hospital stay was nine days (mean ± SD, 8.8 ± 1.6 days), with no one suffering 90-day surgical morbidity and mortality, and all patients getting symptoms improvement. During the follow-up period (mean ± SD, 24 ± 10 months), one patient suffered a small residual asymptomatic celiac artery aneurysm (8 mm in diameter) and was treated conservatively due to underlying liver cirrhosis. Conclusion: Surgical management is a feasible, effective, and safe alternative for splanchnic aneurysms after failed endovascular therapy. [ABSTRACT FROM AUTHOR]

Testicular torsion is a commonly encountered medical emergency in children. A 10-year-old boy with diagnostically confirmed leukemia presented with new onset testis swelling. Scrotal ultrasound showed absent blood flow on the left, consistent with acute testicular torsion. The patient underwent left orchiectomy due to the testis being unsalvageable. Later pathology confirmed lymphoblastic infiltrates. A malignancy of the testicles is rarely associated with torsion and, in the setting of leukemia, suggests widespread disease. Due to the risk of scrotal violation, an inguinal approach is preferable for surgical exploration of the testicles in patients with a history of leukemia.

Background: Magnetic resonance imaging (MRI) is not routinely ordered following spinal fusion. Some literature suggests MRIs are unhelpful due to postoperative changes that obscure interpretation. We aim to describe findings of acute postoperative MRI following anterior cervical discectomy and fusion (ACDF). Methods: The authors retrospectively analyzed adult MRIs completed within 30 days of ACDF (from 2005–2022). T1 and T2 signal intensity in the interbody space dorsal to the graft, mass effect on the dura/spinal cord, intrinsic spinal cord T2 signal, and interpretability were reviewed. Results: In 38 patients there were 58 ACDF levels (1, 2, and 3 levels; 23, 10, and 5, respectively). MRIs were completed on mean postoperative day 8.37 (range; 0–30 days). T1-weighted imaging was described as isointense, hyperintense, heterogenous, and hypointense in 48 (82.8%), 5 (8.6%), 3 (5.2%), and 2 levels (3.4%), respectively. T2-weighted imaging was described as hyperintense, heterogenous, isointense, and hypointense in 41 (70.7%), 12 (20.7%), 3 (5.2%), and 2 levels (3.4%), respectively. There was no mass effect in 27 levels (46.6%), 14 (24.1%) had thecal sac compression, and 17 (29.3%) had cord compression. Conclusions: The majority of MRIs exhibited readily compression and intrinsic spinal cord signal even with various types of fusion constructs. Early MRI after lumbar surgery can be difficult to interpret. However, our results support the use of early MRI to investigate neurological complaints following ACDF. Our findings do not support the idea that epidural blood products and mass effect on the cord are seen in most postoperative MRIs after ACDF.

In the present report, we have described the case of a significantly delayed presentation of a pseudoaneurysm (PSA) and subsequent mass effect causing an acute deep vein thrombosis (DVT). The patient had presented with a mass in the right groin and edema of the right lower extremity prompting further imaging studies. The imaging studies demonstrated a superficial femoral artery PSA and an acute femoral vein DVT. Our patient had no history of recent trauma or femoral access procedures performed in the last ≥5 years. Surgical repair of the PSA was performed, and the DVT was managed with anticoagulation therapy.

Ewing's sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) belongs to the family of malignant small and blue round cell tumors. It usually occurs in children and young adults with 3/4th of the cases arising from bone and 1/4 from soft tissue. Here, we present two cases of intracranial ES/pPNET who presented with mass effect. Management consists of surgical excision followed by adjuvant chemotherapy. Intracranial ES/pPNETs are highly aggressive and rare malignancies, reported to comprise of 0.03% of all intracranial tumors. The most common genetic aberration associated with ES/pPNET is chromosomal translocation t (11,12) (q24;q12). Patients with intracranial ES/pPNETs may present in acute or delayed manner. The presenting symptoms and signs depend on the location of the tumor. Intracranial pPNET although slow growing, they are highly vascular and may present as neurosurgical emergencies due to mass effect. We have presented the acute presentation of this tumor and its management. [ABSTRACT FROM AUTHOR]

Background and Objectives: Giant bullae rupture easily and cause tension pneumothorax, which can cause problems during general anesthesia. However, the hemodynamic instability that can occur due to the mass effect of an unruptured giant bulla should not be overlooked. Case report: A 43-year-old male patient visited the emergency room with an abdominal wound. There was a giant emphysematous bulla in the left lung. Emergency surgery was decided upon because there was active bleeding according to abdominal CT. After tracheal intubation, the patient’s blood pressure and pulse rate dramatically decreased. His blood pressure did not recover despite the use of vasopressors and discontinuation of positive pressure ventilation applied to the lungs. Thus, a bullectomy was immediately performed. The patient’s blood pressure and pulse rate were normalized after the bullectomy. Conclusions: If emergency surgery under general anesthesia is required in a patient with a giant emphysematous bulla, it is safe to minimize positive pressure ventilation and remove the giant emphysematous bulla as soon as possible before proceeding with the remainder of the surgery. Tension pneumothorax due to the rupturing of a bulla should be considered first. However, hemodynamic changes might occur due to the mass effect caused by a giant bulla.

Compared to the secondary brain injury after intracerebral haemorrhage (ICH), fewer reports focused on the mechanism of primary brain injury induced by mass effect. Here, the tandem mass tag (TMT) labeling proteomics method was used to study the mechanical damage of the mass effect after ICH. A total of 5390 proteins were identified, and 4593 proteins were quantified, included 80 up-regulated proteins (M/N Ratio > 1.2) and 30 down-regulated proteins (M/N Ratio > 1.2). Bioinformatics and enrichment analysis showed that the differentially expressed proteins were mainly involved in immune response, signal transmission, and oxidative phosphorylation. The mass effect affects the synthesis and metabolism of ATP by mechanically stretching and squeezing the brain tissue. Furthermore, the cell morphology and dendritic development of neurons were also significantly influenced by mass effect, which also cause neuronal damage through the formation of oxidative stress and oxygen-glucose deprivation, and activate the neuronal protection and defense mechanisms. Our results provide the relevant channels and key proteins of primary brain injury caused by mass effect after ICH, which offer a scientific basis for the understanding of ICH injury.

Abstract Background Many pancreatic pseudocysts spontaneously resolve, but larger or symptomatic pseudocysts may require procedural management. Though endoscopic ultrasound guided approaches are standard of care and have high success rates, complications can include bleeding, infection, and splenic perforation. This patient case report details an unusual series of complications of endoscopic cystogastrostomy that should encourage clinicians to evaluate for anatomic disruptions caused by mass effects of pancreatic pseudocysts prior to endoscopic pseudocyst drainage. Case presentation A 53-year-old African American male with a past medical history notable for alcohol use disorder, chronic pancreatitis, and insulin dependent diabetes presented with a 4-day history of left upper quadrant abdominal pain. Computed tomography imaging with contrast revealed enlargement of a known pancreatic pseudocyst to 15.9 × 10.4 cm. Due to pseudocyst size and the patient’s symptoms, endoscopic cystogastrostomy stent placement was performed. However, postprocedurally, he developed leukocytosis to 19,800 cells/m3 (from 14,100 cells/m3 preoperatively) as well as acute hypoxemic respiratory failure with a large left pleural effusion. Postprocedural computed tomography with contrast demonstrated a new large subcapsular splenic hematoma in communication with a new subdiaphragmatic fluid collection. Due to suspicion of endoscopic procedural complication, he underwent open laparotomy which revealed grade 4 splenic laceration, septic splenic hematoma, and a subdiaphragmatic abscess. Conclusions While endoscopic drainage of pancreatic pseudocyst was technically successful, this case demonstrates complications from mass effect of a large pancreatic pseudocyst which putatively tore the splenorenal ligament, leading to excessive separation of the left kidney and spleen. If anatomic disruptions caused by mass effect from a pancreatic pseudocyst are recognized through preprocedural abdominal imaging, such cases may be considered for early open repair versus cystogastrostomy.

The paper offers a reading of Mass Effect: Andromeda (BioWare, 2017) vis-à-vis lost world romance (also dubbed “lost race romance”, or “imperial romance”), a late-Victorian era novelistic genre originating from H. Rider Haggard’s King Solomon’s Mines and serving as a major tool for British Empire propaganda and a source of early science-fiction conventions. We claim that the narrative failure of this ill-received game stems from its adherence to the rigid principles and forceful themes of the genre and the colonial and imperial imaginary informing it. Our analysis aims at highlighting the way 19th-century novelistic convention can be remediated as contemporary digital games, and to expose the link between the imperial imaginary and the ways in which open-world digital games are structured, on both the narrative and gameplay levels, even when they do not directly refer to the historical colonial legacy.

Abstract Elevation is involved in determining plant diversity in montane ecosystems. This study examined whether the distribution of plants in the Yatsugatake Mountains, central Japan, substantiated hypotheses associated with an elevational diversity gradient. Species richness of trees, shrubs, herbs, ferns, and bryophytes was investigated in study plots established at 200‐m elevational intervals from 1,800 to 2,800 m. The changes in plant diversity (alpha and beta diversities, plant functional types, and elevational ranges) with elevation were analyzed in relation to climatic factors and elevational diversity gradient hypotheses, that is, mass effect, mid‐domain effect, and Rapoport's elevational rule. In addition, the elevational patterns of dominance of plant functional types were also analyzed. A comparison of alpha and beta diversities revealed that different plant groups responded variably to elevation; the alpha diversity of trees and ferns decreased, that of herbs increased, whereas the alpha diversity of shrubs and bryophytes showed a U‐shaped relationship and a hump‐shaped pattern. The beta diversity of shrubs, herbs, and bryophytes increased above the subalpine–alpine ecotone. In accordance with these changes, the dominance of evergreen shrubs and graminoids increased above this ecotone, whereas that of evergreen trees and liverworts decreased. None of the plant groups showed a wide elevational range at higher elevations. These elevational patterns of plant groups were explained by climatic factors, and not by elevational diversity gradient hypotheses. Of note, the changes in the dominance of plant groups with elevation can be attributed to plant–plant interactions via competition for light and the changes in physical habitat. These interactions could alter the elevational diversity gradient shaped by climatic factors.

In near-natural basins, zooplankton are key hubs for maintaining aquatic food webs and organic matter cycles. However, the spatial patterns and drivers of zooplankton in streams are poorly understood. This study registered 165 species of zooplankton from 147 sampling sites (Protozoa, Rotifers, Cladocera and Copepods), integrating multiple dimensions (i.e., taxonomic, functional, and phylogenetic) and components (i.e., total, turnover, and nestedness) of α and β diversity. This study aims to reveal spatial patterns, mechanisms, correlations, and relative contribution of abiotic factors (i.e., local environment, geo-climatic, land use, and spatial factors) through spatial interpolation (ordinary kriging), mantel test, and variance partitioning analysis (VPA). The study found that α diversity is concentrated in the north, while β diversity is more in the west, which may be affected by typical habitat, hydrological dynamics and underlying mechanisms. Taxonomic and phylogenetic β diversity is dominated by turnover, and metacommunity heterogeneity is the result of substitution of species and phylogeny along environmental spatial gradients. Taxonomic and phylogenetic β diversity were strongly correlated (r from 0.91 to 0.95), mainly explained by historical/spatial isolation processes, community composition, generation time, and reproductive characteristics, and this correlation provides surrogate information for freshwater conservation priorities. In addition, spatial factors affect functional and phylogenetic α diversity (26%, 28%), and environmental filtering and spatial processes combine to drive taxonomic α diversity (10%) and phylogenetic β diversity (11%). Studies suggest that spatial factors are key to controlling the community structure of zooplankton assemblages in near-natural streams, and that the relative role of local environments may depend on the dispersal capacity of species. In terms of diversity conservation, sites with high variation in uniqueness should be protected (i) with a focus on the western part of the thousand islands lake catchment and (ii) increasing effective dispersal between communities to facilitate genetic and food chain transmission. [Display omitted] • Unravelling the relative roles of abiotic factors on zooplankton α and β diversity. • Phylogenetic and taxonomic β diversity are highly correlated. • Spatial factors strongly affect phylogenetic and functional α diversity. • Environmental filtering and spatial processes co-drive phylogenetic β diversity. • Zooplankton diversity protection should focus on the western TIL catchment. [ABSTRACT FROM AUTHOR]

Ophthalmic artery (OA) is a potential origin of aneurysms. We present a patient with a giant OA aneurysm, with a sudden onset of psychomotor agitation at the admission. Digital subtraction angiography showed an aneurysm originating from the ophthalmic segment of the left internal carotid artery of irregular shape, with diameters up to 6.5 x 4.5 mm, while the neck of the aneurysm was 4 mm wide. On computed tomography angiography, the aneurysm was seen as much larger and round, up to 4.7 cm in diameter and with a calcified wall. In the further course of treatment, the microcatheter was placed in the lumen of the aneurysm and the embolization spirals were set within. This resulted in a complete exclusion of the aneurysm from the circulation. Endovascular treatment for the giant OA aneurysm, such as coil embolization technique, might be successful for the complete exclusion from circulation of a giant and partially thrombosed aneurysm. [ABSTRACT FROM AUTHOR]

Simple Summary: A growing high-grade glioma exerts a local pressure on its surroundings, resulting in a tissue displacement known as the gross mass effect that is considered a major cause of acute neurological symptoms in patients with brain cancer. Mass effects are usually manifested when significant deformations caused by the tumor growth are observed radiologically or clinically; however, minor deformations in peritumoral tissue could provide early evidence of processes related to tumor relapse and recurrence. In this study, we propose an automated method to quantify the subtle deformations that occur in the peritumoral region. We also propose four biomarkers for differentiating where peritumoral displacements translate into compression. Biomarkers quantifying peritumoral compression were found to be associated with patient progression and prognosis and demonstrated the ability to stratify patients between long-time and short-time survivors. We conclude that compression biomarkers can be key to early treatment assessment during follow-up. The compression of peritumoral healthy tissue in brain tumor patients is considered a major cause of the life-threatening neurologic symptoms. Although significant deformations caused by the tumor growth can be observed radiologically, the quantification of minor tissue deformations have not been widely investigated. In this study, we propose a method to quantify subtle peritumoral deformations. A total of 127 MRI longitudinal studies from 23 patients with high-grade glioma were included. We estimate longitudinal displacement fields based on a symmetric normalization algorithm and we propose four biomarkers. We assess the interpatient and intrapatient association between proposed biomarkers and the survival based on Cox analyses, and the potential of the biomarkers to stratify patients according to their survival based on Kaplan–Meier analysis. Biomarkers show a significant intrapatient association with survival (p < 0.05); however, only compression biomarkers show the ability to stratify patients between those with higher and lower overall survival (AUC = 0.83, HR = 6.30, p < 0.05 for CompCH). The compression biomarkers present three times higher Hazard Ratios than those representing only displacement. Our study provides a robust and automated method for quantifying and delineating compression in the peritumoral area. Based on the proposed methodology, we found an association between lower compression in the peritumoral area and good prognosis in high-grade glial tumors. [ABSTRACT FROM AUTHOR]

Comparing spatio-temporal patterns between planktonic and benthic algae is helpful for understanding their associations and differences. However, such studies are still rare especially in large rivers. We used a dataset collected in the upper reach of the Jinsha River in different seasons to explore biodiversity and assembly processes of planktonic and benthic diatom assemblages. We found that planktonic and benthic diatoms presented different seasonal variation in species richness and community compositions. We also found evidence that planktonic and benthic diatoms were coupled in the summer. Planktonic diatom assemblages were mainly affected by spatial processes via directional spatial dispersal, especially in the summer. By comparison, benthic diatom assemblages were more affected by environmental processes. Our findings suggest that mass effect and species sorting paradigms explain the assembly processes of planktonic and benthic diatom assemblages, respectively, but the explanatory powers of these two paradigms vary seasonally. To effectively monitor and assess ecological conditions of large rivers, we recommend using benthic algae as a biotic indicator group as they had stronger correlations with environmental factors. [ABSTRACT FROM AUTHOR]

MS (multiple sclerosis) has specific criteria to avoid misdiagnosis. However, the Marburg variant of MS is so fulminant that initial axonal damage and other atypical observations have been allowed in past reports. We present a 74-year-old autopsy case with a vanishing tumor after steroids and radiation therapy, which was pathologically diagnosed as a Marburg variant with initial axonal loss. The case displayed radiological lymphoma-like observations: mass effects protruding to the lateral ventricle, fused extension from the choroid plexus to white matter with C opening sign, a growing lesion from the skull dura mater, high in diffusion-weighted imaging and low in apparent diffusion coefficient on magnetic resonance imaging (MRI) suggesting high cell density lymphoma. In addition, clinical manifestations were atypical for MS: upper limb monoplegia without ipsilateral lower limb involvement, pleocytosis over 50 cells/μL, and class 3 cytological abnormality in cerebrospinal fluid. However, at autopsy following steroids and radiation therapy, there were no lymphoma-like lesions, such as mass effects, fused extensive lesions, masses on the skull dura mater, or high cell density lesions. Instead, there were only myelin losses corresponding to the MRI lesions, highlighting the potential for contamination by other diseases in steroid-modified Marburg's variant of multiple sclerosis, possibly due to lymphoma, even at autopsy., Competing Interests: The authors declare that they have no conflicts of interest., (© 2024 The Authors.)

Bioassessment is widely used to measure ecological integrity of natural habitats following anthropogenic disturbances and modifications. Traditionally, bioassessment has been based exclusively on species-environment interactions, i.e. niche processes. However, dispersal processes, and in particular mass effect, could mask the influence of niche processes and lead to erroneous conclusions about ecosystem health. To circumvent this problem, we identified 40 diatom species with distributions driven primarily by mass effect and propose an alternative version of the Biological Diatom Index (IBD2007) excluding these species. We tested the environmental responses of both the original IBD (IBD2007) and the modified IBD (IBDmod) with a benthic diatom dataset from France, collected between 2007 and 2013 and including 9487 samples from 3913 spatially distinct localities. Our results indicate a better relationship between the IBDmod scores and environmental conditions, compared to the IBD2007 scores, leading to a more accurate determination of river ecological status, especially in conditions of moderate nutrient enrichment. This study supports the idea that mass effect may result in biased evaluation of water quality. It is advocated that this process is considered in other diatom-based indices, and by extension, in any biotic index.

Background: Many pancreatic pseudocysts spontaneously resolve, but larger or symptomatic pseudocysts may require procedural management. Though endoscopic ultrasound guided approaches are standard of care and have high success rates, complications can include bleeding, infection, and splenic perforation. This patient case report details an unusual series of complications of endoscopic cystogastrostomy that should encourage clinicians to evaluate for anatomic disruptions caused by mass effects of pancreatic pseudocysts prior to endoscopic pseudocyst drainage.Case Presentation: A 53-year-old African American male with a past medical history notable for alcohol use disorder, chronic pancreatitis, and insulin dependent diabetes presented with a 4-day history of left upper quadrant abdominal pain. Computed tomography imaging with contrast revealed enlargement of a known pancreatic pseudocyst to 15.9 × 10.4 cm. Due to pseudocyst size and the patient's symptoms, endoscopic cystogastrostomy stent placement was performed. However, postprocedurally, he developed leukocytosis to 19,800 cells/m3 (from 14,100 cells/m3 preoperatively) as well as acute hypoxemic respiratory failure with a large left pleural effusion. Postprocedural computed tomography with contrast demonstrated a new large subcapsular splenic hematoma in communication with a new subdiaphragmatic fluid collection. Due to suspicion of endoscopic procedural complication, he underwent open laparotomy which revealed grade 4 splenic laceration, septic splenic hematoma, and a subdiaphragmatic abscess.Conclusions: While endoscopic drainage of pancreatic pseudocyst was technically successful, this case demonstrates complications from mass effect of a large pancreatic pseudocyst which putatively tore the splenorenal ligament, leading to excessive separation of the left kidney and spleen. If anatomic disruptions caused by mass effect from a pancreatic pseudocyst are recognized through preprocedural abdominal imaging, such cases may be considered for early open repair versus cystogastrostomy. [ABSTRACT FROM AUTHOR]

Elevation is involved in determining plant diversity in montane ecosystems. This study examined whether the distribution of plants in the Yatsugatake Mountains, central Japan, substantiated hypotheses associated with an elevational diversity gradient. Species richness of trees, shrubs, herbs, ferns, and bryophytes was investigated in study plots established at 200‐m elevational intervals from 1,800 to 2,800 m. The changes in plant diversity (alpha and beta diversities, plant functional types, and elevational ranges) with elevation were analyzed in relation to climatic factors and elevational diversity gradient hypotheses, that is, mass effect, mid‐domain effect, and Rapoport's elevational rule. In addition, the elevational patterns of dominance of plant functional types were also analyzed. A comparison of alpha and beta diversities revealed that different plant groups responded variably to elevation; the alpha diversity of trees and ferns decreased, that of herbs increased, whereas the alpha diversity of shrubs and bryophytes showed a U‐shaped relationship and a hump‐shaped pattern. The beta diversity of shrubs, herbs, and bryophytes increased above the subalpine–alpine ecotone. In accordance with these changes, the dominance of evergreen shrubs and graminoids increased above this ecotone, whereas that of evergreen trees and liverworts decreased. None of the plant groups showed a wide elevational range at higher elevations. These elevational patterns of plant groups were explained by climatic factors, and not by elevational diversity gradient hypotheses. Of note, the changes in the dominance of plant groups with elevation can be attributed to plant–plant interactions via competition for light and the changes in physical habitat. These interactions could alter the elevational diversity gradient shaped by climatic factors. [ABSTRACT FROM AUTHOR]

The paper offers a reading of Mass Effect: Andromeda (BioWare, 2017) vis-à-vis lost world romance (also dubbed "lost race romance", or "imperial romance"), a late-Victorian era novelistic genre originating from H. Rider Haggard's King Solomon's Mines and serving as a major tool for British Empire propaganda and a source of early science-fiction conventions. We claim that the narrative failure of this ill-received game stems from its adherence to the rigid principles and forceful themes of the genre and the colonial and imperial imaginary informing it. Our analysis aims at highlighting the way 19th-century novelistic convention can be remediated as contemporary digital games, and to expose the link between the imperial imaginary and the ways in which open-world digital games are structured, on both the narrative and gameplay levels, even when they do not directly refer to the historical colonial legacy. [ABSTRACT FROM AUTHOR]

Demyelinating lesions which present as solitary contrast-enhancing masses pose a diagnostic challenge for both radiologists and surgical neuropathologists and can mimic a number of intracranial space occupying lesions either neoplastic/inflammatory. Herein, a series of seven cases with particular emphasis on histopathological and immunohistochemical characterisation of these lesions was presented. The seven cases of Tumefactive Demyelinating Lesions (TDLs) diagnosed on histopathology include three males and four females with age ranging from 10 to 58 years (median-25 years) chiefly presenting with focal neurological deficits. Radiologically, the lesions were predominantly localised in the temporo-parietal region. Histologically, the lesions were well-demarcated, hypercellular with infiltration by foamy macrophages and reactive astrocytes. In addition, Creutzfeldt astrocytes and granular mitoses were seen. Additional special stains for myelin (Luxol fast blue), demonstrated focal, sharply marginated loss of myelin, and Immunohistochemistry (IHC) with Neurofilament (NF) for axons showed relative preservation of axons in areas of myelin loss. IHC with Glial Fibrillary Acidic Protein (GFAP) highlighted the fibrillary processes of the reactive astrocytes and the cytoplasm of the Creutzfeldt cells. Knowledge of the characteristic features such as welldemarcated lesions with histological characterisation by large number of macrophages, including Creutzfeldt astrocytes, granular mitoses and perivascular inflammation should raise index of suspicion and prompt pathologist to do additional myelin stains and IHC to confirm demyelination and preservation of intact axons thereby, differentiating from neoplasms and other non-neoplastic inflammatory lesions.

Understanding how species richness changes along altitudinal gradients and what mechanisms answer for those patterns has intrigued increasing attention from numerous researchers, however, there is still no consistent agreement on these questions. Here, based on available distribution records, we explored the elevational pattern of species richness for seed plants in the Mt. Namjagbarwa region (Eastern Himalayas, China), a previously unexplored region. Species richness in each 100 m elevation band was estimated by spatial interpolation method according to their recorded elevation range over a large altitudinal gradient from 700 to 5000 m. In each elevation band, species richness was related to several explanatory factors, including temperature, humidity, spatially related variables and biogeographical distributions. Regression analyses were performed to obtain a quantitative assessment of the relative contribution of each predictor to the empirical richness pattern. Overall, species richness along elevation showed a hump-shaped pattern, with a peak at 1600–2000 m. In all sub-groups (life form, biogeographical affinity, and range-size category), species richness showed unimodal patterns with increasing elevation generally, but with different peak positions. Regression models indicated species richness patterns are highly correlated with energy-related factor in most data sets, explaining the observed richness patterns, but also more or less associated with other variables (climatic variation, area, precipitation, and mid-domain effect). The water-energy dynamics model was found to explain the elevational species richness patterns. Meantime, there was an elevational coincidence between maximum species richness and floristic overlap index, which proving the role of the biotic process in shaping the species richness gradient. Our findings reconfirmed that the elevational richness gradient is influenced by many processes, including ecological factors and evolutionary history, and suggested the need to consider more factors in order to determine key mechanisms in future studies.

Background: Brain metastasis (BM) from colorectal cancer (CRC) is rare with the incidence ranging from 0.6% to 3.2%. There is also an increased incidence of BM with rectal primaries and is consistent with this patient’s presentation. Overall, there is scarce literature on the symptoms of patients who present with CRC BMs. Objectives: We present a case of brain metastasis in colorectal cancer presenting with hypertensive urgency and severe headache. Methods and results: This case highlights that neurological deficits are not necessary for BMs in patients with CRC and summarizes and reviews the associated literature regarding BM in CRC. A 57-year-old female with a past medical history of recently diagnosed stage IV moderately differentiated distal rectal adenocarcinoma with liver and lung metastasis was admitted with the primary complaint of hypertensive urgency, severe headache, intractable nausea and vomiting, and diarrhea. Magnetic resonance imaging brain showed a left cerebellar lesion measuring 3.6 × 3.2 × 2.9 cm, ipsilateral transtentorial herniation, and obliteration of the fourth ventricle. The patient was started on steroids and transferred for an urgent neurosurgical intervention to a tertiary care center. Conclusions: Even though BMs are rare in CRC, clinicians should have a high index of suspicion with complaints like hypertensive urgency, headache, nausea, vomiting, vertigo, and blurring of vision triggering imaging studies to rule out BM. The approach to BM has become increasingly individualized as surgical and radiosurgical therapies have continued to evolve Abbreviations: CRC: Colorectal cancer; BM: Brain metastasis; FOLFOX: Folinic acid, fluorouracil and oxaliplatin; CT: Computed tomography; IV: Intravenous; PO: By mouth; BAER: Brain auditory evoked response hearing testing; SSEP’s: Somatosensory evoked potentials; BMFI: Brain metastasis free interval; WBRT: Whole-brain radiation therapy; SRS: Stereotactic radiosurgery.

Demyelinating lesions which present as solitary contrast-enhancing masses pose a diagnostic challenge for both radiologists and surgical neuropathologists and can mimic a number of intracranial space occupying lesions either neoplastic/inflammatory. Herein, a series of seven cases with particular emphasis on histopathological and immunohistochemical characterisation of these lesions was presented. The seven cases of Tumefactive Demyelinating Lesions (TDLs) diagnosed on histopathology include three males and four females with age ranging from 10 to 58 years (median-25 years) chiefly presenting with focal neurological deficits. Radiologically, the lesions were predominantly localised in the temporo-parietal region. Histologically, the lesions were well-demarcated, hypercellular with infiltration by foamy macrophages and reactive astrocytes. In addition, Creutzfeldt astrocytes and granular mitoses were seen. Additional special stains for myelin (Luxol fast blue), demonstrated focal, sharply marginated loss of myelin, and Immunohistochemistry (IHC) with Neurofilament (NF) for axons showed relative preservation of axons in areas of myelin loss. IHC with Glial Fibrillary Acidic Protein (GFAP) highlighted the fibrillary processes of the reactive astrocytes and the cytoplasm of the Creutzfeldt cells. Knowledge of the characteristic features such as welldemarcated lesions with histological characterisation by large number of macrophages, including Creutzfeldt astrocytes, granular mitoses and perivascular inflammation should raise index of suspicion and prompt pathologist to do additional myelin stains and IHC to confirm demyelination and preservation of intact axons thereby, differentiating from neoplasms and other non-neoplastic inflammatory lesions. [ABSTRACT FROM AUTHOR]

• "Giant" gallbladder development in the context of acute on chronic cholecystitis is extremely rare and may present with atypical symptoms secondary to mass effect. • Current grading systems for acute cholecystitis severity do not include assessment based on size making them insufficient in predicting "giant" gallbladder surgical prognosis. • Laparoscopic cholecystectomy was performed successfully despite the large gallbladder size without intraoperative/postoperative complications. Gallbladder disease is a common surgical pathology. Gallstones can remain asymptomatic or develop into an acute cholecystitis and need for surgical intervention. Significant enlargement of the gallbladder well beyond the normal volume is rare. Such "giant" gallbladders can affect feasibility of subsequent management options. An 80-year-old female presented to the emergency department with a two-day history of acute on chronic gastric reflux with nausea and vomiting. On examination, she had right upper quadrant abdominal pain. CT imaging identified an enormous gallbladder creating mass effect and compression on the distal stomach. She underwent successful laparoscopic cholecystectomy and was discharged from the hospital the next day, doing well. On two-week follow up, her reflux symptoms had completely resolved and she had no complaints. Giant gallbladders are a rare entity. Our patient's case is unique in both its occurrence as well as presentation with predominant reflux symptoms secondary to mass effect by the enlarged gallbladder. Current cholecystitis grading systems do not utilize size as a means of predicting severity and risk of operative complications or difficulty of procedure. Laparoscopic cholecystectomy was a successful approach in managing this extreme pathology. Updated classifications systems that include size and mass effect as a predictive measure are needed to better assess surgical outcomes, especially in "giant" gallbladder disease. Despite the large size and potential mass effect on surrounding structures, laparoscopic cholecystectomy can still be attempted if no other contraindications exist. [ABSTRACT FROM AUTHOR]

• The processes that structure rodent metacommunities change across the region. • Environmental processes determine the species composition in each local community. • Environmental processes determine relative abundance of each species in each local community. • Spatial processes vary among ecoregions. • Species-specific dispersal characteristics act differentially in each ecoregion. We studied the role of spatial (regional) and environmental (local) processes in the structuring of rodent metacommunities in three contiguous ecoregions that share the same species pool. The two northern ecoregions are mainly affected by anthropogenic processes (agriculture and urbanization) while the southern one is mainly affected by natural processes (flood and drought pulses). Local communities were described based on the analysis of 77 samples of barn owl pellets. To identify which processes (patch dynamics, species sorting, mass effect or neutral theory) structure each metacommunity we evaluated the percentage of variance explained by space (spatial arrangement of communities) and environment (topography, climate and land cover) in three Variation Partitioning Redundancy Analyses. The percentage of variance in rodent metacommunities composition explained by space and environment was between 38 and 61%, and was significant in all three analyses. The pure space fraction was significant for two of the three ecoregions, while the pure environmental fraction was significant for all three ecoregions. The processes that structure rodent metacommunities change across the region. In all three ecoregions the species sorting played a key role, while, mass effect was a structuring factor for northern metacommunities. These results can be explained by species-specific dispersal characteristics and environmental filtering. [ABSTRACT FROM AUTHOR]

Objective: With today's modern imaging modalities, patients diagnosed with renal cell carcinoma (RCC) rarely present symptomatically. In some cases, however, they can develop paraneoplastic syndromes with associated symptoms. To date, only three cases of RCC presenting with chronic dry cough have been reported. We describe six patients who presented with cough that improved following radical nephrectomy. Methods: A retrospective review of patients undergoing partial or radical nephrectomy for renal masses between January 2015 and March 2016 was performed, and patients presenting with a cough were examined. Results: Six patients presented with chronic cough and were discovered to have a large renal mass. Postoperative spontaneous resolution of cough was noted in all but one patient, in whom coughing was reduced and limited to the mornings. Cough duration ranged from 3 months to just over a year. All patients were treated with radical nephrectomy, which was cytoreductive in four patients. Average tumor size was 10.9 cm (SD = 2.2 cm). Five of the tumors had clear cell pathology, and every tumor was Fuhrman grade IV, unifocal, and demonstrated necrosis. Sarcomatoid features were reported in four of the tumors. Conclusion: Our study presents the largest series of patients with RCC who presented with a chronic cough that was significantly improved following radical nephrectomy. We believe the cause of cough is multifactorial and further investigation is needed to clearly elucidate the etiology.

Background: Mass effect associated with large or giant aneurysms is an intractable problem for traditional endovascular treatments. Preventing recurrence of aneurysms requires dense coiling, which may aggravate the mass effect. However, the flow diverter (FD) is a new device that avoids the need for dense coiling. This study was performed to investigate whether use of FDs with adjunctive coil embolization can relieve the aneurysmal mass effect and to explore the factors that affect the variation of compressional symptoms.Methods: We retrospectively evaluated patients with compressional symptoms caused by unruptured aneurysms who underwent endovascular treatment with an FD with adjunctive coil embolization at our center from January 2015 to December 2017. Imaging follow-up included digital subtraction angiography (DSA) ranging from 11 to 14 months and magnetic resonance imaging (MRI) ranging from 24 to 30 months; the former was used to evaluate the intracavitary volume, and the latter was used to measure the variation of the mass effect. Follow-up physical examinations were performed to observe variations of symptoms.Results: In total, 22 patients with 22 aneurysms were treated by an FD combined with coil embolization. All 22 patients underwent the last clinical follow-up. Regarding compressional symptoms, 12 (54.54%) patients showed improvement, 6 (27.27%) were fully recovered, and 6 (27.27%) showed improvement but with incomplete cranial palsy. However, five (22.72%) patients showed no change, four (18.18%) showed worsening symptoms compared with their preoperative state, and one (4.55%) died of delayed rupture. Seventeen of the 22 patients underwent MRI. Of these 17 patients, the aneurysm shrank in 13 (76.47%) and no significant change occurred in 4 (23.53%). In the multivariate analysis, a short duration from symptom occurrence to treatment (p = 0.03) and younger patient age (p = 0.038) were statistically significant factors benefiting symptom improvement, and shrinkage of the aneurysm was associated with favorable clinical outcomes (p = 0.006).Conclusions: Use of the FD with adjunctive loose coil embolization might help to alleviate the compressional symptoms caused by intracranial aneurysms. Shrinkage of the aneurysm, a short duration of symptoms, and younger patient age might contribute to favorable outcomes of mass effect-related symptoms.

Background: Mass effect associated with large or giant aneurysms is an intractable problem for traditional endovascular treatments. Preventing recurrence of aneurysms requires dense coiling, which may aggravate the mass effect. However, the flow diverter (FD) is a new device that avoids the need for dense coiling. This study was performed to investigate whether use of FDs with adjunctive coil embolization can relieve the aneurysmal mass effect and to explore the factors that affect the variation of compressional symptoms. Methods: We retrospectively evaluated patients with compressional symptoms caused by unruptured aneurysms who underwent endovascular treatment with an FD with adjunctive coil embolization at our center from January 2015 to December 2017. Imaging follow-up included digital subtraction angiography (DSA) ranging from 11 to 14 months and magnetic resonance imaging (MRI) ranging from 24 to 30 months; the former was used to evaluate the intracavitary volume, and the latter was used to measure the variation of the mass effect. Follow-up physical examinations were performed to observe variations of symptoms. Results: In total, 22 patients with 22 aneurysms were treated by an FD combined with coil embolization. All 22 patients underwent the last clinical follow-up. Regarding compressional symptoms, 12 (54.54%) patients showed improvement, 6 (27.27%) were fully recovered, and 6 (27.27%) showed improvement but with incomplete cranial palsy. However, five (22.72%) patients showed no change, four (18.18%) showed worsening symptoms compared with their preoperative state, and one (4.55%) died of delayed rupture. Seventeen of the 22 patients underwent MRI. Of these 17 patients, the aneurysm shrank in 13 (76.47%) and no significant change occurred in 4 (23.53%). In the multivariate analysis, a short duration from symptom occurrence to treatment (p = 0.03) and younger patient age (p = 0.038) were statistically significant factors benefiting symptom improvement, and shrinkage of the aneurysm was associated with favorable clinical outcomes (p = 0.006). Conclusions: Use of the FD with adjunctive loose coil embolization might help to alleviate the compressional symptoms caused by intracranial aneurysms. Shrinkage of the aneurysm, a short duration of symptoms, and younger patient age might contribute to favorable outcomes of mass effect-related symptoms. [ABSTRACT FROM AUTHOR]

Highlights • There is an indirect effect of plant diversity on litter decomposition. • Taxonomic, functional components and environmental factors affect litter decomposition. • The effects of diversity on the decomposition process vary with time. Abstract One of the challenges in predicting the effects of biodiversity on ecosystem functioning is understanding the balance between the importance of various diversity components and variations in the environment. In mega-diverse tropical forests, these relationships between plant diversity and ecosystem processes, such as litter decomposition, are poorly explored. While the direct effects of plant diversity on litter decomposition are relatively well known, the indirect effects of diversity, and the local community and microenvironment have rarely been investigated. We evaluated the indirect effects of plant diversity on litter decomposition in a tropical forest. We assessed diversity using different components (plant species richness, functional composition, and functional diversity), evaluated the environmental gradient (soil attributes, topography and canopy cover) and related it to the dynamics of litter decomposition. A 230-day in situ experiment was performed in the southern areas of the Brazilian Atlantic forest using litterbags filled with standard substrate (to test the indirect effects) to evaluate the decomposition rates. In parallel, we also conducted a taxonomic and functional survey of the vegetation in the area of influence of the decomposition experiment. We demonstrated that there is an indirect effect of plant diversity, via taxonomic and functional diversities, on litter decomposition. The indirect effect is more pronounced at the beginning of the decomposition process, and the influences of different components of diversity and ecological mechanisms (niche complementarity, mass effect and selection effect) vary over time. Our study revealed the importance of not only small-scale variations in the biotic component but also those of soil in ecosystem functioning in a megadiverse forest. In this way, we have contributed to a better understanding of the determinants of the decomposition process, in addition to those suggested by classical theoretical models (i.e., climate, litter composition and decomposers). [ABSTRACT FROM AUTHOR]

We present an efficient numerical method to quantify the spatial variation of glioma growth based on subject-specific medical images using a mechanically-coupled tumor model. The method is illustrated in a murine model of glioma in which we consider the tumor as a growing elastic mass that continuously deforms the surrounding healthy-appearing brain tissue. As an inverse parameter identification problem, we quantify the volumetric growth of glioma and the growth component of deformation by fitting the model predicted cell density to the cell density estimated using the diffusion-weighted magnetic resonance imaging data. Numerically, we developed an adjoint-based approach to solve the optimization problem. Results on a set of experimentally measured, in vivo rat glioma data indicate good agreement between the fitted and measured tumor area and suggest a wide variation of in-plane glioma growth with the growth-induced Jacobian ranging from 1.0 to 6.0. [ABSTRACT FROM AUTHOR]

Studying an opportunity to optimize the treatment of the patients with severe traumatic brain injuries is a topical issue in modern neurosurgery. Traumatic tension pneumocephalus is one of life-threatening conditions which accompanies severe TB1 and is often complicated with posttraumatic liquorrhea and mass effect. Materials and methods. We carried out systematic search in Russian and foreign medical databases (Medline, Russian Science Citation Index, EMedicine, UMKB) concerning our theme. We included the following words in our search request: tension pneumocephalus, mass effect, valve mechanism, treatment. The result of conducted review of literature was writing the clinic lecture, studying current status of the problem of etiopathogenesis, diagnostics and surveillance of the patients with tension pneumocephalus. The article presenas clinical case of successful surgical treatment of a patient with traumatic tension pneumocephalus. Conclusion. There are no uniform standards of urveillance of the patients with tension pneumocephalus. Based on our own experience, we determined that minimally invasive surgery is a method of choice among reconstructive craniofacial surgeries in the treatment of patients with traumatic tension pneumocephalus. It decreases the risks of intra- and postoperative complication. Compliance, using external ventricular drainage and repeated lumbar punctures with prevention of inflammatory complications helped stopping nasal liquorrhea and eliminating mass effect which caused absolute regression of neurological signs.

Although cerebral edema is a major cause of death and deterioration following hemispheric stroke, there remains no validated biomarker that captures the full spectrum of this critical complication. We recently demonstrated that reduction in intracranial cerebrospinal fluid (CSF) volume (∆CSF) on serial computed tomography (CT) scans provides an accurate measure of cerebral edema severity, which may aid in early triaging of stroke patients for craniectomy. However, application of such a volumetric approach would be too cumbersome to perform manually on serial scans in a real-world setting. We developed and validated an automated technique for CSF segmentation via integration of random forest (RF) based machine learning with geodesic active contour (GAC) segmentation. The proposed RF + GAC approach was compared to conventional Hounsfield Unit (HU) thresholding and RF segmentation methods using Dice similarity coefficient (DSC) and the correlation of volumetric measurements, with manual delineation serving as the ground truth. CSF spaces were outlined on scans performed at baseline (

Background: Brain metastasis (BM) from colorectal cancer (CRC) is rare with the incidence ranging from 0.6% to 3.2%. There is also an increased incidence of BM with rectal primaries and is consistent with this patient’s presentation. Overall, there is scarce literature on the symptoms of patients who present with CRC BMs. Objectives: We present a case of brain metastasis in colorectal cancer presenting with hypertensive urgency and severe headache. Methods and results: This case highlights that neurological deficits are not necessary for BMs in patients with CRC and summarizes and reviews the associated literature regarding BM in CRC. A 57-year-old female with a past medical history of recently diagnosed stage IV moderately differentiated distal rectal adenocarcinoma with liver and lung metastasis was admitted with the primary complaint of hypertensive urgency, severe headache, intractable nausea and vomiting, and diarrhea. Magnetic resonance imaging brain showed a left cerebellar lesion measuring 3.6 × 3.2 × 2.9 cm, ipsilateral transtentorial herniation, and obliteration of the fourth ventricle. The patient was started on steroids and transferred for an urgent neurosurgical intervention to a tertiary care center. Conclusions: Even though BMs are rare in CRC, clinicians should have a high index of suspicion with complaints like hypertensive urgency, headache, nausea, vomiting, vertigo, and blurring of vision triggering imaging studies to rule out BM. The approach to BM has become increasingly individualized as surgical and radiosurgical therapies have continued to evolve Abbreviations: CRC: Colorectal cancer; BM: Brain metastasis; FOLFOX: Folinic acid, fluorouracil and oxaliplatin; CT: Computed tomography; IV: Intravenous; PO: By mouth; BAER: Brain auditory evoked response hearing testing; SSEP’s: Somatosensory evoked potentials; BMFI: Brain metastasis free interval; WBRT: Whole-brain radiation therapy; SRS: Stereotactic radiosurgery. [ABSTRACT FROM AUTHOR]