Total Beta Research Articles

Protected areas are not effective for the conservation of freshwater insects in Brazil

Biodiversity conservation has faced many challenges, especially the conversion of natural areas that compete with use for agriculture, energy production and mineral extraction. This problem is further aggravated by lack of knowledge of the biodiversity that exists and the geographical distribution of different groups. The objectives of our study were to examine the distributional pattern of Gerromorpha diversity in Brazil, create a map of conservation priority areas, estimate the degree of protection that the current network of protected areas guarantees to this insect group, and identify the size thresholds in geographical distributions that would allow species to be protected. We used species occurrences from the Water Bugs Distributional Database, and we used 19 bioclimatic variables to build models of the potential distributions of species using the MaxEnt program. Using the potential model results, we calculated diversity metrics and overlapped them with the current state and federal “conservation units” (protected areas for biodiversity) in Brazil. Total beta diversity and turnover portions were separated into two faunistic groups, one in northern and the other in southern Brazil. The Amazon has higher beta diversity than what was predicted by the null models. We detected a positive relationship between species distribution area and occurrence in conservation units. Conservation units with less than 250 km2 do not protect Gerromorpha species. Our results reinforce the necessity of formulating new conservation strategies for this group, contemplating species with both restricted and ample distributions, because rare and specialist species are the most harmed by habitat reduction, given that they are more sensitive to environmental disturbance.

Subthalamic Peak Beta Ratio Is Asymmetric in Glucocerebrosidase Mutation Carriers With Parkinson's Disease: A Pilot Study.

Introduction: Up to 27% of individuals undergoing subthalamic nucleus deep brain stimulation (STN-DBS) have a genetic form of Parkinson's disease (PD). Glucocerebrosidase (GBA) mutation carriers, compared to sporadic PD, present with a more aggressive disease, less asymmetry, and fare worse on cognitive outcomes with STN-DBS. Evaluating STN intra-operative local field potentials provide the opportunity to assess and compare symmetry between GBA and non-GBA mutation carriers with PD; thus, providing insight into genotype and STN physiology, and eligibility for and programming of STN-DBS. The purpose of this pilot study was to test differences in left and right STN resting state beta power in non-GBA and GBA mutation carriers with PD.Materials and Methods: STN (left and right) resting state local field potentials were recorded intraoperatively from 4 GBA and 5 non-GBA patients with PD while off medication. Peak beta power expressed as a ratio to total beta power (peak beta ratio) was compared between STN hemispheres and groups while co-varying for age, age of disease onset, and disease severity.Results: Peak beta ratio was significantly different between the left and the right STN for the GBA group (p < 0.01) but not the non-GBA group (p = 0.56) after co-varying for age, age of disease onset, and disease severity.Discussion: Peak beta ratio in GBA mutation carriers was more asymmetric compared with non-mutation carriers and this corresponded with the degree of clinical asymmetry as measured by rating scales. This finding suggests that GBA mutation carriers have a physiologic signature that is distinct from that found in sporadic PD.

Effects of mode and timing of calcium chloride application on tissue calcium concentration and acceptability of mango fruits

Mango (Mangifera indica L) production in Kenya directly supports approximately 200,000 farmers and many other beneficiaries. Despite this, its production suffers from post-harvest losses due to the fruits' short shelf life in ambient conditions. Calcium maintains cell integrity, strengthens the cell wall, membrane structure, and thus increases shelf life. A completely randomized block design with a split plot arrangement was used to compare the effect of spraying and immersion of ‘Van Dyke' mango fruits at maturity or 15 days later in calcium chloride at different concentrations (0.5%, 1%, 1.5%, or 0%) and times on the fruit ripening rate and organoleptic acceptance. The peel firmness (N), total soluble solids (0Brix), flesh color (Ho), beta carotene (mg/100ml), and carbon dioxide evolution (ml/kg/hr) of fruits were determined at time 0 and every two days for up to eight days in ambient conditions. Additionally, organoleptic characteristics, flesh firmness, calcium concentration (g/mg), and their correlations were determined. Fruits immersed in calcium chloride at maturity had higher retained peel firmness (10.6 N, 10.3 N), deeper flesh color (37.45, 36.78), lower total soluble solids (14, 13.8), a lower carbon dioxide evolution (30.7 ml/kg/hr), higher beta carotene and higher flesh calcium concentration than fruits exposed to other treatments. Fruits sprayed at maturity outperformed those sprayed 15 days later in the studied parameters. Flesh calcium content correlated positively with flesh firmness (r= 0.913, r= 0.852), flesh color (r= 0.828, r= 0.841), fruit aroma (r=0.8199, r=0.841), and negatively with skin shriveling (r=-0.778, r=-0.806) and fruit flavor (r=-0.811, r=-0.829). Flesh firmness correlated negatively with skin shriveling (r=-0.868, r=-0.788) and fruit flavor (r=-0.8869, r=-0.821), but positively with peel color (r=0.9115, r=0.856) and aroma (r=0.907, r=0.848). Skin shriveling was found to have a negative relationship with peel color (r=-0.944, r=-0.93) and aroma (r=-0.944, r=-0.938), but a positive relationship with fruit flavor (r=0.933, r=0.947). Peel color correlated positively with aroma (r=0.979, r=0.977) and negatively with fruit flavor (r=-0.962, r=-0.950), respectively. Despite the effectiveness of post-harvest calcium chloride immersion in extending fruit shelf life, optimal use is advised to avoid deteriorated pulp flavor and increased shriveling. More research is needed to determine how calcium chloride can be made available to the fruit while it is still attached to the tree.

Yöresel Bazı Bitkiler ile Aromatize Edilen Zeytinyağlarının Stabilitelerinin Araştırılması

The aims of this study were to evaluate the total phenolic and pigment contents of five edible plants collected from Eastern Black Sea region and to test the storage stability of extra virgin olive oils aromatized with traditionally consumed plants. Aromatized extra virgin olive oils were prepared by addition of dry forms of local plants such as mendek (Aegopodium podagraria L.), çalıçilek (Vaccinium myrtillus L.), galdirik (Trachystemon orientalis L.), sakarca (Ornithogalum umbellatum L.) and hırnık (Diospyros lotus L.). Changes in the quality status of extra virgin olive oil were monitored with free fatty acid, peroxide value, total phenol content, pheophtyin a, lutein and beta carotene analyses during 5-month storage period at 24°C. Furthermore, hue and chrome values, total phenolic, chlorophyll and carotene contents were also analysed to determine the characteristic properties of plant samples. The addition of mendek and çalıçilek have remarkable effects on the transfer of phenolic compounds and pigments from plants to oil during all storage. It was determined that the addition of plant materials can improve the oil stability and cause to a lower free fatty acid and peroxide values in aromatized extra virgin olive oils. Obtained findings suggest that the aromatized olive oils with local plants is sensorial and nutritionally acceptable and can be used safely in aromatization and preparation of healthy and tasty foods at non-thermal process.

Characterisation of Ppy-lineage cells clarifies the functional heterogeneity of pancreatic beta cells in mice

Aims/hypothesisPancreatic polypeptide (PP) cells, which secrete PP (encoded by the Ppy gene), are a minor population of pancreatic endocrine cells. Although it has been reported that the loss of beta cell identity might be associated with beta-to-PP cell-fate conversion, at present, little is known regarding the characteristics of Ppy-lineage cells.MethodsWe used Ppy-Cre driver mice and a PP-specific monoclonal antibody to investigate the association between Ppy-lineage cells and beta cells. The molecular profiles of endocrine cells were investigated by single-cell transcriptome analysis and the glucose responsiveness of beta cells was assessed by Ca2+ imaging. Diabetic conditions were experimentally induced in mice by either streptozotocin or diphtheria toxin.ResultsPpy-lineage cells were found to contribute to the four major types of endocrine cells, including beta cells. Ppy-lineage beta cells are a minor subpopulation, accounting for 12–15% of total beta cells, and are mostly (81.2%) localised at the islet periphery. Unbiased single-cell analysis with a Ppy-lineage tracer demonstrated that beta cells are composed of seven clusters, which are categorised into two groups (i.e. Ppy-lineage and non-Ppy-lineage beta cells). These subpopulations of beta cells demonstrated distinct characteristics regarding their functionality and gene expression profiles. Ppy-lineage beta cells had a reduced glucose-stimulated Ca2+ signalling response and were increased in number in experimental diabetes models.Conclusions/interpretationOur results indicate that an unexpected degree of beta cell heterogeneity is defined by Ppy gene activation, providing valuable insight into the homeostatic regulation of pancreatic islets and future therapeutic strategies against diabetes.Data availabilityThe single-cell RNA sequence (scRNA-seq) analysis datasets generated in this study have been deposited in the Gene Expression Omnibus (GEO) under the accession number GSE166164 (www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE166164).Graphical abstract

Standardisation and Sensory Evaluation of Fruit Powder based Instant Health Drink Mix

Mango and pineapple powders were prepared for the processing and sensory evaluation of fruit powder based instant health drink mixes and standardised using various levels of fruit powders (10-50%) with additional ingredients. The mango and pineapple powders of 30 g were taken as optimum level for processing the health drink mixes. The processed mixes were stored in different packaging materials and stored at room temperature for 270 days. The chemical characteristics and microbial load were observed during storage period. Moisture and vitamin C contents were slightly high in pineapple powder based health drink mixes whereas reducing and total sugars, protein, fat and beta carotene were more in mango powder based instant health drink mixes. A minimal rise in microbial population was observed in all the stored samples during the study period. The organoleptic scores of the instant health drink mixes were found to be highly acceptable up to 270 days.

The decrease of histomorphometry and function of pancreas in male albino rats after induced by sleep deprivation

Background: Sleep disturbance accelerates type 2 diabetes mellitus by reducing insulin secretion and by the occurrence of difficulty in controlling sleep behaviour in humans so that it is necessary conduct a study by using experimental animals.Objective: This study aims to determine histophotometric differences of pancreas and differences of glucose tolerance in male albino rats (Rattus norvegicus) after induced by stress paradoxical sleep deprivation (PSD) and total sleep deprivation (TSD). Methods: This study applied a post-test only with control groups consisting of 30 male albino rats (Wistar strain) divided randomly into 3 groups: control group, PSD group and TSD group. The mean number and diameter of islets of Langerhans were calculated per slide and were averaged for each group at a magnification of 400 X. The percentage of beta cells in one islet of Langerhans was (ß-p) that was a number of normal beta cells (Bn) divided for the total beta cells (Bt) (normal and damaged) x 100%. The glucose level based on the sampling time was made a curve shape, and the area under the 0-to-120-minute curves (AUC0-120) was calculated by using a trapezoidal formula.Results: The lowest AUC0-120 level of glucose was the control group (14,082 ± 955mg/dL) and the highest was the TSD group (16,293 ± 2,195 mg/dL); the Post-Hoc LSD test showed a significant difference (p&lt;0.05) between the control-PSD group and the TSD-control group. The mean result of pancreatic ß cells mass with the lowest number was in the TSD group (76.3 ± 4.8), and the highest result was in the control group (94.3 ± 2.7); Post-Hoc LSD showed a significant difference (p &lt;0.05) in the control-PSD group and the TSD-control group. The lowest mean in cell diameter of islets of Langerhans was in the TSD group (0.132 ± 0.031 mm), and the highest mean was in the control group (0.213 ± 0.019 mm). Conclusion: Sleep deprivation could reduce pancreatic ß cell mass and cell diameter of islets of Langerhans and increase glucose tolerance levels.

The status and trends in radioactive contamination of groundwater at a LLW-ILW storage facility site near Sosnovy Bor (Leningrad region, Russia)

The article presents results of field studies at a site of radioactive waste storage and disposal facilities (the so-called LD RosRAO site, Sosnovy Bor, Leningrad region, Russia). The objective of the study is to overview the history and occurrence of groundwater contamination to answer the question whether the radioactive plume is historical (formed due to accidents, which happened at the beginning of the operations with the radioactive waste) or the release of radioactive solutions to groundwater is still occurring. The main method used to study the evolution of radioactive contamination is to analyze long-term observations of tritium, total alpha, and total beta activities in groundwater samples. The role of the hydrogeological conditions of the site, such as flow parameters, groundwater flow pattern, inter-aquifer downward groundwater leakage, and water-table fluctuations, in the evolution of contamination plumes has also been analyzed. In the field investigations, the integrity of the storage buildings to potential leaks was confirmed by different indirect methods. It was concluded that there is currently no significant release of radioactive components into groundwater at the LD RosRAO site and that the present conditions correspond to the stage of rehabilitation of the groundwater environment.

Assessing the natural and anthropogenic radionuclide activities of the Pechora River estuary: Bottom sediments and water (Arctic Ocean Basin)

This paper studies the activity of natural and technogenic radionuclides in bottom sediments and surface water of the Pechora River estuary, which is the largest Arctic river within the European part of Russia. The relevance of conducting radioecological studies of this region is associated with active oil and gas activities in the Pechora basin and the presence of potential sources of radiation hazard. The average activities of 137Cs, 226Ra, 232Th, and 40K in bottom sediments were 0.16, 18.72, 13.36, and 373.59 Bq·kg-1, respectively. The average activity of 226Ra in the bottom sediments of the Pechora delta was two times higher than in other rivers of the Arctic basin of the European part of Russia, which is associated with oil and gas activities that are carried out in the Pechora basin. This is due to the fact that the decay products of uranium are the main by-products of oil and gas production. The specific activity of technogenic 137Cs in bottom sediments of the Pechora River delta was low and did not exceed 2.2 Bq·kg-1. We did not detect any radioactive 90Sr in bottom sediments. The low 137Cs activity in the bottom sediments of the Pechora delta was associated with both the larger granulometric composition of the sediments in comparison with the estuaries of the Siberian rivers, and with low concentrations of 137Cs in the terrigenous material (soil) entering the river from the catchment area. This was due to the low levels of 137Cs contamination in the soil of the Pechora river basin. We did not find any negative radiation effects of the underground nuclear explosion “Pyrite” carried out in the northern part of the delta, since there were no other technogenic radionuclides. The values of the radionuclides 3H, 137Cs, 226Ra, 232Th and 40K, as well as the total alpha activity in the surface waters of the Pechora River delta, turned out to be below the detection limit. In surface waters, we were able to determine only the total beta activity, which varied over a range from 19.6 to 59.6 Bq·m-3 with an average value of 33.9 Bq·m-3, which was significantly lower than the radiation safety standards. The values of the radiation hazard parameters were below the world average levels and were not significantly hazardous to the health of people living in the area of the Pechora River delta. We concluded that at present, in the Pechora River delta, there are pastures for reindeer with low levels of natural and man-made radioactivity. These conducted studies are the source material in a series of comprehensive studies of the current radioecological state of the tundra territories of the European part of Russia.

Effect of chilli varieties and storage conditions on quality attributes of honey chilli sauce: A preservation study

The honey chilli sauce was standardized using green and red CH-27 and Punjab sindhuri chilli varieties. The samples were stored at ambient (25 ± 2℃) as well as refrigeration (4 ± 2℃) temperature and analyzed for up to 8 months with 2 months interval. Honey chilli sauce with CH-27 red was found to be significantly (p ≤ .05) highest in total phenolic components, beta carotene, lycopene and antioxidant activities while total solids, ash content and ascorbic acid content were highly retained in samples containing Punjab sindhuri red chilli variety. All the samples were acceptable even after 8 months of storage based on their sensory scores with intact nutrients. Novelty impact statement Honey chilli sauce containing Punjab sindhuri red chilli scored the highest sensory scores due to its bright red color. Honey chilli sauce may add spice and flavor to cuisine and can be used as a wonderful dip aside from a dish. Value addition of chilli with honey can add flavor as well as health-promoting properties of both to the food.

Homogenization of diatom assemblages is driven by eutrophication in tropical reservoirs

Eutrophication is one of the most widespread causes of biotic homogenization in freshwater ecosystems. Biotic homogenization can be characterized as reductions in local diversity (alpha) and occupation of available niches by more generalist species. Beta diversity is expected to decrease in more homogeneous communities, however, there is no consensus on how it responds to eutrophication. We used a space-for-time approach to analyze the process of biotic homogenization on diatom assemblages in response to eutrophication in tropical reservoirs ranging from oligotrophic to hypereutrophic conditions. Diatom assemblages were analyzed in phytoplankton and surface sediment from 12 reservoirs with different trophic levels. We calculated total beta diversity and turnover and nestedness components and used regressions to analyze their relationships with productivity differences (without distance effects). Total beta diversity had a positive influence of the trophic gradient, whereas turnover was not related to eutrophication. However, we found that eutrophication and lower species richness (alpha diversity) led to increasing rates of the nestedness component. We also observed that the homogenization process was not characterized by invasion of new species, but, on the contrary, by filtering nutrient-rich tolerant species also present in oligo-mesotrophic reservoirs and able to occupy available niches in the eutrophic reservoirs. These findings (increase in nestedness, decrease in alpha diversity, and development of tolerant species) suggest that biotic homogenization is leading to a simplification of diatom assemblages in tropical reservoirs, making assemblages from eutrophic and hypereutrophic reservoirs a subset of assemblages from oligotrophic and mesotrophic ones.

Multiple facets of macrophyte beta diversity are shaped by environmental factors, directional spatial processes, and connectivity across tropical floodplain lakes in the dry season

A multi-faceted approach is needed to better understand how the beta diversity of aquatic assemblages responds to ecological gradients. Using distance-based RDA and variance partitioning, we explored the different components of total beta diversity (replacement and richness difference) based on taxonomic, functional, and phylogenetic data of aquatic macrophytes along environmental and spatial gradients across 49 tropical floodplain lakes in the Pantanal of Mato Grosso in the dry season. We found that taxonomic beta diversity was driven by species replacement, while functional beta diversity was mostly contributed by richness difference and phylogenetic beta diversity was equally contributed by both components. Taxonomic and functional beta diversities were driven by environmental variables, connectivity variables, and directional spatial processes. Phylogenetic beta diversity was mainly affected by the connectivity between the sites and their distance from the river. The relationship between environmental variables and beta diversity indicates that a selection of species with similar functional and phylogenetic characteristics co-occurs at a site. The low connectivity between sites and the increased distance between the lakes and the river suggested dispersal limitation, which was due to the absence of directional exchange of species between lakes. Our findings provided new insights into the beta diversity patterns of aquatic macrophytes and their underlying causes in tropical floodplains.

Determinants of different facets of beta diversity in Mediterranean marine amphipods

Relying on a purely taxonomic view of diversity may ignore the fact that ecological communities can be constituted of species having both distinct evolutionary histories and functional characteristics. Thus, considering how the multiple facets of diversity vary along environmental and geographic gradients may provide insights into the role of historic processes and current environmental conditions in determining the distribution of species, lineages and functions across space. Using distributional, taxonomic-distance and traits information, we explored the role of spatial/environmental gradients and of biogeographic subdivision of Mediterranean Sea on the different facets and components of beta diversity in seagrass amphipods. Beta diversity partitioning and correlation analyses showed a nearly equal contribution of the replacement and richness components on total beta diversity for all facets, although the influence of environmental and geographic distance differed among components. While the replacement was mainly related to a pure spatial gradient, both the environmental and geographic distances were correlated with the richness component of beta diversities. Our results are in line with the complex paleobiogeographic history of the Mediterranean Sea, with the replacement component likely related to the progressive substitution of species of Atlantic origin with Mediterranean endemics along the west–east geographic gradient, and the richness component to the marked environmental difference between different basins. Moreover, the influence of biogeographic partition on the richness components suggests a role of spatially structured gradients at biogeographic level in determining the net loss/gain of species, lineages and functions.

Saliva Neurofilament Light Chain Is Not a Diagnostic Biomarker for Neurodegeneration in a Mixed Memory Clinic Population.

Neurodegeneration and axonal injury result in an increasing release of neurofilament light chain (NfL) into bodily fluids, including cerebrospinal fluid (CSF) and blood. Numerous studies have shown that NfL levels in CSF and blood are increased in neurodegenerative disorders and monitor neurodegeneration. Saliva is an easily accessible biofluid that could be utilized as a biofluid measurement of Alzheimer’s disease (AD) biomarkers. In this study, for the first time, salivary NfL was measured and compared to plasma NfL in a consecutive cohort of patients referred to cognitive assessments. In two mixed memory clinic cohorts, saliva samples were taken from 152 patients, AD (n = 49), mild cognitive impairment (MCI) (n = 47), non-AD (n = 56), and also 17 healthy controls. In addition, 135 also had a matching plasma sample. All saliva and plasma samples were analyzed for NfL, and the association between saliva and plasma NfL and CSF levels of total tau (t-tau), phosphorylated tau (p-tau), and beta amyloid 1–42 (Aβ42) were investigated. In total, 162/169 had quantifiable levels of salivary NfL by single molecule array (Simoa). No statistically significant differences were found in salivary NfL concentration across the diagnostic groups, but as expected, significant increases were found for plasma NfL in dementia cases (P < 0.0001). There was no association between saliva and plasma NfL levels. Furthermore, saliva NfL did not correlate with CSF Aβ42, p-tau, or tau concentrations. In conclusion, NfL is detectable in saliva but does not reflect neurodegeneration in the brain.

389 The Association between Arousals and Neurochemical Biomarkers Accumulation in Obstructive Sleep Apnea with Low Arousal Threshold

Abstract Introduction Previous studies indicated the accumulation of neurodegenerative protein may be caused by higher Obstructive sleep apnea syndrome (OSAS) severity. However, the association between arousal-related parameters induced by OSAS and the amyloid burden remains unclear. The aim of this study is to investigate the association between arousal threshold (ArTH) and neurochemical protein accumulation in OSAS patients. Methods Suspected OSAS participants were performed Mini-mental status examination (MMSE) and full-night polysomnography (PSG) in the sleep center of Taipei Medical University Shuang Ho Hospital, Taiwan. On the same morning, the blood samples were obtained from the participants. The concentrations of total Tau (T-Tau) and amyloid beta peptide 42 (Aβ42) were quantified by ultra-sensitive immunomagnetic reduction assays. An overall of 23 participants were enrolled and classified into Low ArTH group (n=12) and High ArTH group (n=11) based on low ArTH criteria. Regarding the statistical methods, for categorical variables and continuous variables, Fisher’s exact test and Mann-Whitney U test were performed to investigate the differences between groups, respectively. The associations between biomarkers concentrations and PSG parameters were assessed by Spearman’s correlation. Results Regarding the demographic characteristics in two subgroups, significantly lower body-mass index and OSAS severity were noted in Low ArTH group (p&amp;lt;0.05). The MMSE was in normal range in both groups and had no significant differences in subgroups. For PSG parameters, there were significantly lower desaturation index, AHI and higher spontaneous arousals index in each sleep stage in Low ArTH group (p&amp;lt;0.01). Nevertheless, in the plasma neurochemical biomarkers, Aβ42 and Aβ42 X T-Tau were significantly higher in Low ArTH group (p&amp;lt;0.05). Moreover, in Low ArTH group, T-Tau was positively correlated with respiratory arousals index (r=0.61, p&amp;lt;0.05) and all arousals index (r=0.76, p&amp;lt;0.01), respectively. The positive correlations between Aβ42 X T-Tau and respiratory arousals index (r=0.62, p&amp;lt;0.05), all arousals index (r=0.75, p&amp;lt;0.01) could also be observed. There were no significant correlations noted in High ArTH group. Conclusion OSAS patients with low ArTH have higher neurochemical biomarker levels. Also, the significantly positive correlations between arousals and biomarkers were observed in that group. Support (if any):

Physicochemical quality of twin layer solar tunnel dried tomato slices

The objective of this experimental study was to evaluate the effect of twin layer solar tunnel drying on physicochemical quality of tomato slices. The novelty of this dryer is that it has two layers of trays unlike Hohenheim solar tunnel dryer which makes it to have drying capacity of more than two times compare to type hohenheim solar tunnel dryer with equal collector area. The experiment consists of two (tray position and drying position) factors with two levels of tray position (upper tray (samples exposed to direct solar radiation) and lower tray (samples are exposed to only heated air)) and three levels of drying position (collector out let,middle of the dryer and dryer out let) with three replications. During the experiment 180 kg of Tomato slices of Galilea variety with 5mm thickness were dried in the twin layer solar tunnel dryer. Data on physicochemical quality of tomato were collected and analyzed using SAS (version 9.2). software. From the experimental result; an increase in lycopene and phenolic content retention along the length of the dryer was observed while Vitamin C retention showed a decreasing trend. Large retention of total phenol, lycopene and beta carotene content were observed for the lower tray dried tomato slices compared to the upper tray dried ones. The water activity and PH values of the solar tunnel dried tomatoes were within the safe range from microbial growth, enzymatic and non-enzymatic browning. Compared to sun drying; solar tunnel dried tomatoes showed a much better nutrient retention for all quality parameters which is comparable with the data reported for energy intensive mechanical dryers.

Cortical network effects of subthalamic deep brain stimulation in a thalamo-cortical microcircuit model

Objective. High frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) suppresses excessive beta band (∼13–30 Hz) activity of the motor cortex in Parkinson’s disease (PD). While the mechanisms of action of STN DBS are not well-understood, strong evidence supports a role for cortical network modulating effects elicited by antidromic activation of cortical axons via the hyperdirect pathway. Approach. A spiking model of the thalamo-cortical microcircuit was developed to examine modulation of cortical network activity by antidromic STN DBS, mediated by direct activation of deep pyramidal neurons (PNs) and subsequent indirect activation of other thalamo-cortical structures. Main results. Increasing synaptic coupling strength from cortical granular to superficial layers, from inhibitory neurons to deep PNs, and from thalamus reticular to relay cells, along with thalamocortical connection strength, accompanied by reduced coupling from cortical superficial to granular layers, from thalamus relay cells to reticular neurons, and corticothalamic connection strength, led to increased beta activity and neural synchrony, as observed in PD. High frequency DBS desynchronized correlated neural activity, resulting in clusters of both excited and inhibited deep cortical PNs. The emergence of additional frequency components in the local field potential (LFP), and increased power at subharmonics of the DBS frequency as observed in patients with dyskinesia during DBS, occurred under different stimulus amplitudes and frequencies. While high-frequency (>100 Hz) DBS suppressed the LFP beta power, low-frequency (<40 Hz) DBS increased beta power when more than 10% of PNs were activated, but reduced the total beta power at lower levels of neural activation. Significance. The results suggest a potential mechanism for experimentally observed alterations in cortical neural activity during DBS via the propagation of DBS stimuli throughout the cortical network, modulated by short-term synaptic plasticity, and the emergence of resonance due to interaction of DBS with existing M1 rhythms by engaging feedforward-feedback loops.

A preparedness study: efficiency calibration and performance testing of LSC cocktails for determination of tritium in river‐water samples as an indicator of the technological start of a new NPP

The LSC instrument was efficiency calibrated for the tritium activity determination in river water samples by the direct measurement and different LSC cocktails were evaluated in the study. The combined standard uncertainty was around 6% at the coverage factor k = 1. The background tritium, total beta- and 137Cs activity concentrations in the Neris River samples were assessed. The obtained mean values were 1.5 Bq L− 1, 25 mBq L− 1, and 3.3 mBq L− 1 (MDA), respectively.

Associations of Age, Gender, and Family Income with Quality of Life in Children With Advanced Cancer.

Background: Children with cancer often experience decreased quality of life (QOL) throughout the illness trajectory. The purpose of this study was to explore the associations of demographic characteristics with QOL in children with advanced cancer. Methods: This secondary analysis was part of a larger randomized clinical trial that evaluated the efficacy of a legacy intervention for children (7-17 years) with relapsed/refractory cancer and their primary parent caregivers. Assessments included child self-reports on the Pediatric Quality of Life Inventory (PedsQL) Cancer Module. Researchers used descriptive and linear regression statistical methods. Results: Children (n = 128) averaged 10.9 years (SD = 3.0). The majority were female (n = 68, 53%), white (n = 107, 84%), had a hematologic malignancy (n = 67, 52%), with family incomes of $50,000 or less (n = 81, 63.3%). Statistically significant positive associations of both age and income level with PedsQL scores were observed (p < .05) but not gender (p > .05). The strongest correlations for age were with the procedural anxiety (beta = 0.42), treatment anxiety (beta = 0.26), and total (beta = 0.28) scores (all p < .01). In general, there was a positive correlation between family income levels and PedsQL scores (p < .05). The strongest correlations for income were with nausea (R = 0.49), appearance (R = 0.44), pain, and treatment anxiety (both R = 0.42) (all p < .01). Associations adjusted for age remained essentially the same (all p < .01). Discussion: Children with advanced cancer with lower family income and younger age are at high risk for poorer QOL. Oncology nurses should seek to identify families who may benefit from additional resources to promote QOL.

Association of CSF proteins with tau and amyloid \u03b2 levels in asymptomatic 70-year-olds

BackgroundIncreased knowledge of the evolution of molecular changes in neurodegenerative disorders such as Alzheimer’s disease (AD) is important for the understanding of disease pathophysiology and also crucial to be able to identify and validate disease biomarkers. While several biological changes that occur early in the disease development have already been recognized, the need for further characterization of the pathophysiological mechanisms behind AD still remains.MethodsIn this study, we investigated cerebrospinal fluid (CSF) levels of 104 proteins in 307 asymptomatic 70-year-olds from the H70 Gothenburg Birth Cohort Studies using a multiplexed antibody- and bead-based technology.ResultsThe protein levels were first correlated with the core AD CSF biomarker concentrations of total tau, phospho-tau and amyloid beta (Aβ42) in all individuals. Sixty-three proteins showed significant correlations to either total tau, phospho-tau or Aβ42. Thereafter, individuals were divided based on CSF Aβ42/Aβ40 ratio and Clinical Dementia Rating (CDR) score to determine if early changes in pathology and cognition had an effect on the correlations. We compared the associations of the analysed proteins with CSF markers between groups and found 33 proteins displaying significantly different associations for amyloid-positive individuals and amyloid-negative individuals, as defined by the CSF Aβ42/Aβ40 ratio. No differences in the associations could be seen for individuals divided by CDR score.ConclusionsWe identified a series of transmembrane proteins, proteins associated with or anchored to the plasma membrane, and proteins involved in or connected to synaptic vesicle transport to be associated with CSF biomarkers of amyloid and tau pathology in AD. Further studies are needed to explore these proteins’ role in AD pathophysiology.