A remarkable new leaf-cutter bee from Thailand (Hymenoptera: Megachilidae)

This is the publisher's version, copyright by Akademie Verlag.A remarkable new species of leaf-cutter bee, Megachile trichorhytisma ENGEL sp. n., is described and figured from two males collected in northern Thailand. The species is placed in a new subgenus, Aethomegachile ENGEL & BAKER subgen. n., and is differentiated from previously known lineages of Megachile

Normal T1 relaxometry and extracellular volume of the pancreas in subjects with no pancreas disease: correlation with age and gender

OBJECTIVE Determine normal T1 and extracellular volume (ECV) of the pancreas in subjects with no pancreas disease and correlate with age and gender SUBJECTS AND METHODS We imaged 120 healthy subjects (age range: 20-78 years) who are on annual screening with MRI/MRCP for the possibility of pancreatic cancer. Subjects had a predisposition to develop pancreatic cancer, but no history of pancreas disease or acute symptoms. Equal number (n=60) of subjects were scanned on either 1.5 T or 3 T scanner using dual flip angle spoiled gradient echo technique incorporating fat suppression and correction for B1 field inhomogeneity. Optimization of imaging parameters were performed using a T1 phantom. ECV was calculated using pre- and post-contrast T1 of the pancreas and plasma. Regression analysis and Mann-Whitney tests were used for statistical analysis. RESULTS Median T1 on 1.5 T was 654 ms (IQR: 608-700); median T1 on 3 T was 717 ms (IQR: 582-850); median ECV on 1.5 T was 0.28 (IQR: 0.21-0.33) and median ECV on 3 T was 0.25 (IQR: 0.19-0.28). Age had a mild positive correlation with T1 (r= 0.24, p= 0.009), but not with ECV (r= 0.06, p=0.54). T1 and ECV were similar in both genders (p >0.05). CONCLUSION This study measured the median T1 and ECV of the pancreas in subjects with no pancreas disease. Pancreas shows longer T1 relaxation times in older population, whereas extracellular fraction remains unchanged. Median T1 values were different between two magnet strengths; however, no difference was seen between genders and ECV fractions

The Connectivity Fingerprint of the Human Frontal Cortex, Subthalamic Nucleus, and Striatum

Within the cortico basal ganglia (BG)–thalamic network, the direct and indirect pathways comprise of projections from the cortex to the striatum (STR), whereas the hyperdirect pathway(s) consist of cortical projections toward the subthalamic nucleus (STN). Each pathway possesses a functionally distinct role for action selection. The current study quantified and compared the structural connectivity between 17 distinct cortical areas with the STN and STR using 7 Tesla diffusion weighted magnetic resonance imaging (dMRI) and resting-state functional MRI (rs-fMRI) in healthy young subjects. The selection of these cortical areas was based on a literature search focusing on animal tracer studies. The results indicate that, relative to other cortical areas, both the STN and STR showed markedly weaker structural connections to areas assumed to be essential for action inhibition such as the inferior frontal cortex pars opercularis. Additionally, the cortical connectivity fingerprint of the STN and STR indicated relatively strong connections to areas related to voluntary motor initiation such as the cingulate motor area and supplementary motor area. Overall the results indicated that the cortical–STN connections were sparser compared to the STR. There were two notable exceptions, namely for the orbitofrontal cortex and ventral medial prefrontal cortex, where a higher tract strength was found for the STN. These two areas are thought to be involved in reward processing and action bias

Dietary and Pharmacologic Manipulations of Host Lipids and Their Interaction with the Gut Microbiome in Non-Human Primates

The gut microbiome influences nutrient processing as well as host physiology. Plasma lipid levels have been associated with the microbiome, although the underlying mechanisms are largely unknown, and the effects of dietary lipids on the gut microbiome in humans are not well-studied. We used a compilation of four studies utilizing non-human primates (Chlorocebus aethiops and Macaca fascicularis) with treatments that manipulated plasma lipid levels using dietary and pharmacological techniques, and characterized the microbiome using 16S rDNA. High-fat diets significantly reduced alpha diversity (Shannon) and the Firmicutes/Bacteroidetes ratio compared to chow diets, even when the diets had different compositions and were applied in different orders. When analyzed for differential abundance using DESeq2, Bulleidia, Clostridium, Ruminococcus, Eubacterium, Coprocacillus, Lachnospira, Blautia, Coprococcus, and Oscillospira were greater in both chow diets while Succinivibrio, Collinsella, Streptococcus, and Lactococcus were greater in both high-fat diets (oleic blend or lard fat source). Dietary cholesterol levels did not affect the microbiome and neither did alterations of plasma lipid levels through treatments of miR-33 antisense oligonucleotide (anti-miR-33), Niemann–Pick C1-Like 1 (NPC1L1) antisense oligonucleotide (ASO), and inducible degrader of LDLR (IDOL) ASO. However, a liver X receptor (LXR) agonist shifted the microbiome and decreased bile acid levels. Fifteen genera increased with the LXR agonist, while seven genera decreased. Pseudomonas increased on the LXR agonist and was negatively correlated to deoxycholic acid, cholic acid, and total bile acids while Ruminococcus was positively correlated with taurolithocholic acid and taurodeoxycholic acid. Seven of the nine bile acids identified in the feces significantly decreased due to the LXR agonist, and total bile acids (nmol/g) was reduced by 62%. These results indicate that plasma lipid levels have, at most, a modest effect on the microbiome, whereas bile acids, derived in part from plasma lipids, are likely responsible for the indirect relationship between lipid levels and the microbiome

High pH Microbial Ecosystems in a Newly Discovered, Ephemeral, Serpentinizing Fluid Seep at Yanartaş (Chimera), Turkey

Gas seeps emanating from Yanartaş (Chimera), Turkey, have been documented for thousands of years. Active serpentinization produces hydrogen and a range of carbon gases that may provide fuel for life. Here we report a newly discovered, ephemeral fluid seep emanating from a small gas vent at Yanartaş. Fluids and biofilms were sampled at the source and points downstream. We describe site conditions, and provide microbiological data in the form of enrichment cultures, Scanning electron microscopy (SEM), carbon and nitrogen isotopic composition of solids, and PCR screens of nitrogen cycle genes. Source fluids are pH 11.95, with a Ca:Mg of ~200, and sediments under the ignited gas seep measure 60°C. Collectively, these data suggest the fluid is the product of active serpentinization at depth. Source sediments are primarily calcite and alteration products (chlorite and montmorillonite). Downstream, biofilms are mixed with montmorillonite. SEM shows biofilms distributed homogeneously with carbonates. Organic carbon accounts for 60% of the total carbon at the source, decreasing downstream to \u3c15% as inorganic carbon precipitates. δ13C ratios of the organic carbon fraction of solids are depleted (−25 to −28‰) relative to the carbonates (−11 to −20‰). We conclude that heterotrophic processes are dominant throughout the surface ecosystem, and carbon fixation may be key down channel. δ15N ratios ~3‰, and absence of nifH in extracted DNA suggest that nitrogen fixation is not occurring in sediments. However, the presence of narG and nirS at most locations and in enrichments indicates genomic potential for nitrate and nitrite reduction. This small seep with shallow run-off is likely ephemeral, but abundant preserved microterracettes in the outflow and the surrounding area suggest it has been present for some time. This site and others like it present an opportunity for investigations of preserved deep biosphere signatures, and subsurface-surface interactions

Effect of Anesthesia on Microelectrode Recordings During Deep Brain Stimulation Surgery:A Narrative Review

Deep brain stimulation (DBS) is an effective surgical treatment for patients with various neurological and psychiatric disorders. Clinical improvements rely on careful patient selection and accurate electrode placement. A common method for target localization is intraoperative microelectrode recording (MER). To facilitate MER, DBS surgery is traditionally performed under local or regional anesthesia. However, sedation or general anesthesia is sometimes needed for patients who are unable to tolerate the procedure fully awake because of severe motor symptoms, psychological distress, pain, or other forms of discomfort. The effect of anesthetic drugs on MER is controversial but likely depends on the type and dose of a particular anesthetic agent, underlying disease, and surgical target. In this narrative review, we provide an overview of the current literature on the anesthetic drugs most often used for sedation and anesthesia during DBS surgery, with a focus on their effects on MERs

Association of Pancreatic Steatosis With Chronic Pancreatitis, Obesity, and Type 2 Diabetes Mellitus

Objective: The aim of this study was to determine the association of the pancreatic steatosis with obesity, chronic pancreatitis (CP), and type 2 diabetes mellitus. Methods: Patients (n = 118) were retrospectively identified and categorized into no CP (n = 60), mild (n = 21), moderate (n = 27), and severe CP (n = 10) groups based on clinical history and magnetic resonance cholangiopancreatography using the Cambridge classification as the diagnostic standard. Visceral and subcutaneous compartments were manually segmented, and fat tissue was quantitatively measured on axial magnetic resonance imaging. Results: Pancreatic fat fraction showed a direct correlation with fat within the visceral compartment (r = 0.54). Patients with CP showed higher visceral fat (P = 0.01) and pancreatic fat fraction (P < 0.001): mild, 24%; moderate, 23%; severe CP, 21%; no CP group, 15%. Patients with type 2 diabetes mellitus showed higher pancreatic steatosis (P = 0.03) and higher visceral (P = 0.007) and subcutaneous fat (P = 0.004). Interobserver variability of measuring fat by magnetic resonance imaging was excellent (r ≥ 0.90–0.99). Conclusions: Increased visceral adipose tissue has a moderate direct correlation with pancreatic fat fraction. Chronic pancreatitis is associated with higher pancreatic fat fraction and visceral fat. Type 2 diabetes mellitus is associated with higher pancreatic fat fraction and visceral and subcutaneous adiposity

Simulation-based analysis of micro-robots swimming at the center and near the wall of circular mini-channels

Swimming micro robots have great potential in biomedical applications such as targeted drug delivery, medical diagnosis, and destroying blood clots in arteries. Inspired by swimming micro organisms, micro robots can move in biofluids with helical tails attached to their bodies. In order to design and navigate micro robots, hydrodynamic characteristics of the flow field must be understood well. This work presents computational fluid dynamics (CFD) modeling and analysis of the flow due to the motion of micro robots that consist of magnetic heads and helical tails inside fluid-filled channels akin to bodily conduits; special emphasis is on the effects of the radial position of the robot. Time-averaged velocities, forces, torques, and efficiency of the micro robots placed in the channels are analyzed as functions of rotation frequency, helical pitch (wavelength) and helical radius (amplitude) of the tail. Results indicate that robots move faster and more efficiently near the wall than at the center of the channel. Forces acting on micro robots are asymmetrical due to the chirality of the robot’s tail and its motion. Moreover, robots placed near the wall have a different flow pattern around the head when compared to in-center and unbounded swimmers. According to simulation results, time-averaged for-ward velocity of the robot agrees well with the experimental values measured previously for a robot with almost the same dimensions

High pH microbial ecosystems in a newly discovered, ephemeral, serpentinizing fluid seep at YanartaÅŸ (Chimera), Turkey

Gas seeps emanating from ophiolites at Yanartaş (Chimaera), Turkey, have been documented for thousands of years. Active serpentinization produces hydrogen and a range of carbon gases that may provide fuel for life. Here we report a newly discovered, ephemeral fluid seep emanating from a small gas vent at Yanartaş. Fluids and biofilms were sampled at the source and points downstream. We describe site conditions, and provide microbiological data in the form of enrichment cultures, scanning electron microscopy (SEM), carbon and nitrogen isotopic composition of solids, and PCR screens of nitrogen cycle genes. Source fluids are pH 11.95, with a Ca:Mg of ~200, and sediments under the ignited gas seep measure 60°C. Collectively, these data suggest the fluid is the product of active serpentinization at depth. Source sediments are primarily calcite and alteration products (chlorite and montmorillonite). Downstream, biofilms are mixed with montmorillonite. SEM shows biofilms distributed homogeneously with carbonates. Organic carbon accounts for 60% of the total carbon at the source, decreasing downstream to <15% as inorganic carbon precipitates. δ13C ratios of the organic carbon fraction of solids are depleted (−25 to −28 ‰) relative to the carbonates (−11 to −20‰). We conclude that heterotrophic processes are dominant throughout the surface ecosystem, and carbon fixation may be key down channel. δ15N ratios ~ 3‰, and absence of nifH in extracted DNA suggest that nitrogen fixation is not occurring in sediments. However, the presence of narG and nirS at most locations and in enrichments indicates genomic potential for nitrate and nitrite reduction. This small seep with shallow run-off is likely ephemeral, but abundant preserved microterracettes in the outflow and the surrounding area suggest it has been present for some time. This site and others like it present an opportunity for investigations of preserved deep biosphere signatures, and subsurface-surface interactions

Cancer and systemic inflammation: treat the tumour and treat the host

Determinants of cancer progression and survival are multifactorial and host responses are increasingly appreciated to have a major role. Indeed, the development and maintenance of a systemic inflammatory response has been consistently observed to confer poorer outcome, in both early and advanced stage disease. For patients, cancer-associated symptoms are of particular importance resulting in a marked impact on day-to-day quality of life and are also associated with poorer outcome. These symptoms are now recognised to cluster with one another with anorexia, weight loss and physical function forming a recognised cluster whereas fatigue, pain and depression forming another. Importantly, it has become apparent that these symptom clusters are associated with presence of a systemic inflammatory response in the patient with cancer. Given the understanding of the above, there is now a need to intervene to moderate systemic inflammatory responses, where present. In this context the rationale for therapeutic intervention using nonselective anti-inflammatory agents is clear and compelling and likely to become a part of routine clinical practice in the near future. The published literature on therapeutic intervention using anti-inflammatory agents for cancer-associated symptoms was reviewed. There are important parallels with the development of useful treatments for the systemic inflammatory response in patients with rheumatological disease and cardiovascular disease