Lower Beta Research Articles

Abnormal timing of slow wave synchronization processes in non-rapid eye movement sleep parasomnias.

Sleepwalking, confusional arousals, and sleep terrors are parasomnias occurring out of non-rapid eye movement (NREM) sleep. Several previous studies have described EEG changes associated with NREM parasomnia episodes, but it remains unclear whether these changes are specific to parasomnia episodes or whether they are part of the normal awakening process. Here we directly compared regional brain activity, measured with high-density (hd-) EEG, between parasomnia episodes and normal awakenings (without behavioral manifestations of parasomnia). Twenty adult patients with non-rapid eye movement parasomnias underwent a baseline hd-EEG recording (256 electrodes) followed by a recovery sleep recording after 25 h of total sleep deprivation, during which auditory stimuli were administered to provoke parasomnia episodes. Both normal awakenings (n = 25) and parasomnia episodes (n = 96) were preceded by large, steep, and "K-complex-like" slow waves in frontal and central brain regions, and by a concomitant increase in high-frequency EEG (beta) activity. Compared to normal awakenings, parasomnia episodes occurred on a less activated EEG background and displayed higher slow wave activity (SWA) and lower beta activity in frontal and central brain regions after movement onset. Our results suggest that non-rapid eye movement awakenings, irrespective of behavioral manifestations of parasomnia episodes, involve an arousal-related slow wave synchronization process that predominantly recruits frontal and central brain areas. In parasomnia episodes, this synchronization process comes into play abnormally during periods of high SWA and is associated with higher SWA after movement onset. Thus, an abnormal timing of arousal-related slow wave synchronization processes could underlie the occurrence of NREM parasomnias.

Impact of economic forces and fundamental variables on REIT returns

ABSTRACT We examine the impacts of economic forces and fundamental variables on REIT returns. Our models endogenously select breakpoints to distinguish the heterogenous nature of the underlying properties with varying risk-return characteristics. Default risk premium and unanticipated inflation had an adverse effect, while GDP and federal funds rate had a positive effect on REITs. Market, size and value risk-premiums are significant for time periods that include the GFC but not for subsequent periods. Momentum is negative and significant for extreme events, and insignificant during calm periods. Higher beta values during the GFC followed by lower beta values confirm ‘leveraging’ and ‘deleveraging’ effects.

To dee or not to dee: costs and benefits of altering the triangularity of a steady-state DEMO-like reactor

Shaping a tokamak plasma to have a negative triangularity may allow operation in an edge-localized mode-free L-mode regime and with a larger strike-point radius, ameliorating divertor power-handling requirements. However, the shaping has a potential drawback in the form of a lower no-wall ideal beta limit, found using the MHD codes chease and dcon. Using the new fusion systems code faroes, we construct a steady-state DEMO2 reactor model. This model is essentially zero-dimensional and neglects variations in physical mechanisms like turbulence, confinement, and radiative power limits, which could have a substantial impact on the conclusions deduced herein. Keeping its shape otherwise constant, we alter the triangularity and compute the effects on the levelized cost of energy (LCOE). If the tokamak is limited to a fixed B field, then unless other means to increase performance (such as reduced turbulence, improved current drive efficiency or higher density operation) can be leveraged, a negative-triangularity reactor is strongly disfavored in the model due to lower β N limits at negative triangularity, which leads to tripling of the LCOE. However, if the reactor is constrained by divertor heat fluxes and not by magnet engineering, then a negative-triangularity reactor with higher B 0 could be favorable: we find a class of solutions at negative triangularity with lower peak heat flux and lower LCOE than those of the equivalent positive triangularity reactors.

Restored saltmarshes have low beta diversity due to limited topographic variation, but this can be countered by management

Abstract Spatial heterogeneity of species (beta diversity) is an important attribute of ecological communities, but is less frequently considered when assessing restoration success than other aspects of diversity (gamma and alpha). Differences in beta diversity between restored and natural sites may arise due to differences in environmental heterogeneity. We used a nested sampling design to survey plant communities and environmental conditions (elevation, redox potential and metrics of topography) on four pairs of restored and natural saltmarshes. We assessed whether there were differences in both alpha and beta diversity between natural and restored sites and analysed their environmental drivers. Topography was an important driver of plant alpha diversity and beta diversity on saltmarshes. The effects of topography were partly indirect, mediated though changes in redox potential, but topography also influenced plant communities independently of both elevation and redox. Restored saltmarshes were less heterogeneous in topography than natural marshes. This reduced topography was reflected in lower beta diversity; plant communities 1 m apart in natural marshes were as dissimilar as those found 20 m apart in restored marshes. Large‐scale topographic manipulation carried out at one site a decade after initial restoration successfully increased topographic heterogeneity and increased beta diversity when surveyed 3 years after manipulation. These changes were still evident when resurveyed after a further 2 years. Synthesis and applications. Increasing environmental heterogeneity can improve restoration outcomes by increasing beta diversity on restored sites. The effect of environmental heterogeneity is likely to be particularly strong within intertidal habitats such as saltmarshes, where small changes in topography can determine whether a species can occur at a given location. Topographic manipulation is a feasible post‐restoration technique that can be applied to ensure restored saltmarshes better meet policy targets of biological, physical and functional equivalence with natural marshes.

Omicron infection enhances Delta antibody immunity in vaccinated persons

The extent to which Omicron infection1–9, with or without previous vaccination, elicits protection against the previously dominant Delta (B.1.617.2) variant is unclear. Here we measured the neutralization capacity against variants of severe acute respiratory syndrome coronavirus 2 in 39 individuals in South Africa infected with the Omicron sublineage BA.1 starting at a median of 6 (interquartile range 3–9) days post symptom onset and continuing until last follow-up sample available, a median of 23 (interquartile range 19–27) days post symptoms to allow BA.1-elicited neutralizing immunity time to develop. Fifteen participants were vaccinated with Pfizer's BNT162b2 or Johnson & Johnson's Ad26.CoV2.S and had BA.1 breakthrough infections, and 24 were unvaccinated. BA.1 neutralization increased from a geometric mean 50% focus reduction neutralization test titre of 42 at enrolment to 575 at the last follow-up time point (13.6-fold) in vaccinated participants and from 46 to 272 (6.0-fold) in unvaccinated participants. Delta virus neutralization also increased, from 192 to 1,091 (5.7-fold) in vaccinated participants and from 28 to 91 (3.0-fold) in unvaccinated participants. At the last time point, unvaccinated individuals infected with BA.1 had low absolute levels of neutralization for the non-BA.1 viruses and 2.2-fold lower BA.1 neutralization, 12.0-fold lower Delta neutralization, 9.6-fold lower Beta variant neutralization, 17.9-fold lower ancestral virus neutralization and 4.8-fold lower Omicron sublineage BA.2 neutralization relative to vaccinated individuals infected with BA.1. These results indicate that hybrid immunity formed by vaccination and Omicron BA.1 infection should be protective against Delta and other variants. By contrast, infection with Omicron BA.1 alone offers limited cross-protection despite moderate enhancement.

Differences in Outcomes in Obese (≥30), Morbidly Obese (≥40), and Super Morbidly Obese (≥50) Pregnancies

BackgroundObesity in pregnancy is an increasing problem in the United States. Obesity in pregnancy can result in dangerous complications such as premature birth, cesarean delivery, gestational diabetes, and preeclampsia. Little is currently known about outcomes in the morbidly (body mass index (BMI) ≥40 kg/m2) and super morbidly obese (BMI ≥50 kg/m2) in pregnant patients. Consequently, it is difficult to adequately counsel patients and plan for delivery care. Most current data groups outcomes for obese patients in general, however, some aspects such as reductions in hormone concentrations in pregnancy vary markedly with increasing weight. Obesity can alter hormone concentrations in pregnancy. For example, significantly lower beta human chorionic gonadotropin concentrations and progesterone are observed with increasing weight. Thus, we hypothesized that there are differences outcomes between obese, morbidly obese, and super morbidly obese pregnancies. The purpose of this study (IRB #202004178) is to analyze pregnancy outcomes of women with body mass index (BMI) ≥40 kg/m2 in comparison to obese women with a BMI of 30‐35 kg/m2 with a more rigorous BMI classification system than has been previously used. Our hypothesis is that morbidly obese and super morbidly obese pregnant women will have significant differences in adverse outcomes compared to obese women.MethodsA retrospective cohort study was performed comparing pregnancy outcomes of women with a BMI ≥ 30kg/m2 who delivered at the University of Iowa Hospitals and Clinics (UIHC) between 2009 and 2020. Data were extracted from the electronic health record (Epic) using the Intergenerational Health Knowledgebase, an enterprise data warehouse for research containing validated data from all pregnancies receiving care at UIHC. Additional data was extracted directly from the medical record. Women were included if they were ≥18 years old, had a singleton pregnancy and BMI ≥ 30 kg/m2, and delivered at UIHC (N=6445). Women were stratified into cohorts based on BMI (35‐39.9, 40‐49.9, 50‐59.9, 60‐69.9, 70‐79.9, ≥80 kg/m2) and compared to women with a BMI of 30‐35 kg/m2. Categorical variables were analyzed by chi square and continuous variables by t‐test. Regression models were created to control for confounding.ResultsStatistically significant increased incidences for gestational diabetes, preeclampsia, newborn hypoglycemia, number of days in the hospital post‐delivery, birthweight, and a composite poor neonatal outcome (P<0.001 for each outcome) were associated with increasing BMI. Both the 1‐ and 5‐minute APGAR scores worsened with increasing BMI (P< 0.001). However, there were decreased rates of caesarean section (P<0.001) and pre‐term birth (P=0.02) associated with increasing BMI. There were no statistically significant differences in neonatal ICU admission, death, respiratory distress, and pulmonary hypoplasia.ConclusionBy identifying pregnancy outcomes using classifications with a smaller BMI range, it will be possible to develop more specific counseling and effective care plans for obese, morbidly obese, and super morbidly obese patients in the future.

Task-Rate-Related Neural Dynamics Using Wireless EEG to Assist Diagnosis and Intervention Planning for Preschoolers with ADHD Exhibiting Heterogeneous Cognitive Proficiency.

This study used a wireless EEG system to investigate neural dynamics in preschoolers with ADHD who exhibited varying cognitive proficiency pertaining to working memory and processing speed abilities. Preschoolers with ADHD exhibiting high cognitive proficiency (ADHD-H, n = 24), those with ADHD exhibiting low cognitive proficiency (ADHD-L, n = 18), and preschoolers with typical development (TD, n = 31) underwent the Conners’ Kiddie Continuous Performance Test and wireless EEG recording under different conditions (rest, slow-rate, and fast-rate task). In the slow-rate task condition, compared with the TD group, the ADHD-H group manifested higher delta and lower beta power in the central region, while the ADHD-L group manifested higher parietal delta power. In the fast-rate task condition, in the parietal region, ADHD-L manifested higher delta power than those in the other two groups (ADHD-H and TD); additionally, ADHD-L manifested higher theta as well as lower alpha and beta power than those with ADHD-H. Unlike those in the TD group, the delta power of both ADHD groups was enhanced in shifting from rest to task conditions. These findings suggest that task-rate-related neural dynamics contain specific neural biomarkers to assist clinical planning for ADHD in preschoolers with heterogeneous cognitive proficiency. The novel wireless EEG system used was convenient and highly suitable for clinical application.

Corticomuscular coherence is reduced in relation to dorsiflexion fatigability to the same extent in adults with cerebral palsy as in neurologically intact adults.

Fatigue is frequent in adults with cerebral palsy (CP) and it is unclear whether this is due to altered corticospinal drive. We aimed to compare changes in corticospinal drive following sustained muscle contractions in adults with CP and neurologically intact (NI) adults. Fourteen adults with CP [age 37.6 (10.1), seven females, GMFCS levels I-II] and ten NI adults [age 35.4 (10.3), 6 females] performed 1-min static dorsiflexion at 30% of maximal voluntary contraction (MVC) before and after a submaximal contraction at 60% MVC. Electroencephalography (EEG) and electromyography (EMG) from the anterior tibial muscle were analyzed to quantify the coupling, expressed by corticomuscular coherence (CMC). Adults with CP had lower MVCs but similar time to exhaustion during the relative load of the fatigability trial. Both groups exhibited fatigability-related changes in EMG median frequency and EMG amplitude. The CP group showed lower beta band (16-35Hz) CMC before fatigability, but both groups decreased beta band CMC following fatigability. There was a linear correlation between decrease of beta band CMC and fatigability-related increase in EMG. Fatigability following static contraction until failure was related to decreased beta band CMC in both NI adults and adults with CP. Our findings indicate that compensatory mechanisms to fatigability are present in both groups, and that fatigability affects the corticospinal drive in the same way. We suggest that the perceived physical fatigue in CP is related to the high relative load of activities of daily living rather than any particular physiological mechanism.

Upper Tract Microbiome Modifications After Lung Transplantation and Its Impact in CLAD

<h3>Purpose</h3> Survival after lung transplantation is limited in large part due to the high incidence of chronic lung allograft dysfunction (CLAD). Infection is a recognized risk factor for the development of CLAD, and both acute infection and chronic lung allograft colonization with microorganisms increase the risk for CLAD. The aim of our study was to analyze nasopharyngeal (NP) microbiome composition and modifications following lung transplantation, with a focus on its relationship with CLAD. <h3>Methods</h3> This was a longitudinal study in which we analyzed bacterial microbiome in NP swab samples in 68 lung transplanted (LT) patients the day of the transplant, when patients were discharged, at 2-5 months and 12 months after lung transplantation. We also analysed NP swab samples from 10 healthy subjects. CLAD was assessed after 2 years of follow-up. DNA was extracted from the NP swabs. To create the amplicon library, the hyper-variable region (V4) of the 16S ribosomal RNA gene was amplified by standard PCR. Amplicons were purified and sequenced in barcoded pools using Illumina MiSeq technology. Raw sequence reads were demultiplexed by using idemp. The resulting single-end reads were processed using the Dada2 pipeline obtaining an amplicon sequence variant table to which taxonomy was assigned. Alpha diversity, including Shannon and Observed indices, and beta diversity metrics were calculated. We compared these metrics and particular taxa relative abundances between samples of LT patients at different time points and samples of healthy subjects. <h3>Results</h3> From the 68 studied patients, 13 developed CLAD during the two years of follow-up. We observed a significant decrease in the Observed index at the day of the discharge and 2-5 months after transplant when compared with healthy subjects. One year after transplant, CLAD patients had higher Shannon diversity than LT patients who did not develop the dysfunction. On the other hand, a lower beta diversity was observed between healthy subjects and patients with no CLAD. Besides, we detected an increased genus in NP swab samples associated with no CLAD also observed in NP samples from healthy subjects. <h3>Conclusion</h3> Nasopharyngeal overall microbiome composition, as well as relative abundances of particular taxa of non-CLAD patients, was closest to the one from healthy subjects suggesting a better outcome of the transplant if better microbiome normalization.

Atlantic Forest birds are more functionally and taxonomically diverse in valley bottoms relative to uplands

The theory behind metacommunity was recently reframed to incorporate the concepts of community ecology. Here we investigate how slight topographic variations might locally create habitat heterogeneity and a system of interchanging bird species (i.e., a metacommunity) in a continuous tropical forest. We studied the distribution of birds in a large and protected Neotropical Forest in southwestern Brazil to understand the influence of valley bottom sites on the taxonomic and functional diversity of the bird communities. As previous studies have shown that specialist species have spatially regular distribution when compared to generalists, in the present study we investigate if topography could influence those local patterns of distribution. We expected (1) to find higher taxonomic and functional diversity in communities of valley bottom areas and (2) lower beta taxonomic and functional diversity of the generalists at the valley bottom, but not of specialists, that should exhibit a somewhat consistent distribution. We gathered information on the composition of local bird communities by deploying eight automatic recording units, four in the valley bottoms and four in the uplands, along 4.3 km trail in the forest interior. Our data showed that bird diversity at the valley bottoms tended to be higher than that at the uplands. Specialist passerine assemblages presented high spatial stability and were regularly distributed throughout the forest. In contrast, generalist passerines have limited trait distribution due to valley bottoms. Because bird communities were distinct from each other, deforestation should have stronger impact in the system if only upland areas are left in the landscape. In this case, species dispersal and coexistence as well as complementary traits have predicted implications for the remaining forest fragments, and management actions should prioritize the conservation of forest fragments that include both bottom valleys and uplands areas.

Effect of air nanobubbles on oxygen transfer, oxygen uptake, and diversity of aerobic microbial consortium in activated sludge reactors

Nanobubbles have the potential to curtail the loss of oxygen during activated sludge aeration due to their extensive surface areas and lack of buoyance in solution. In this study, nanobubble aeration was explored as a novel approach to enhance aerobic activated sludge treatment and benchmarked against coarse bubble aeration at the lab scale. Nanobubble aerated activated sludge reactors achieved greater dissolved oxygen levels at faster rates. Higher soluble chemical oxygen demand removal by 10% was observed when compared to coarse bubble aeration with the same amount of air. The activated sludge produced compact sludge yielding easier waste sludge for subsequent sludge handling. The samples showed fewer filamentous bacteria with a lower relative abundance of floc forming Corynebacterium, Pseudomonas, and Zoogloea in the sludge. The microbiome of the nanobubble-treated activated sludge showed significant shifts in the abundance of community members at the genus level and significantly lower alpha and beta diversities.

Timing of adoption is associated with electrophysiological brain activity and externalizing problems among children adopted internationally.

This study investigated middle childhood resting electroencephalography (EEG) and behavioral adjustment in 35 internationally adopted children removed from early caregiving adversity between 6 and 29 months of age. Older age of adoption was associated with more immature or atypical profiles of middle childhood cortical function, based on higher relative theta power (4-6Hz), lower relative alpha power (7-12Hz), lower peak alpha frequency, and lower absolute beta (13-20Hz) and gamma (21-50Hz) power. More immature or atypical EEG spectral power indirectly linked older age of adoption with increased risk for externalizing problems in middle childhood. The findings add to existing evidence linking duration of early adverse exposures with lasting effects on brain function and behavioral regulation even years after living in a stable adoptive family setting. Findings underscore the need to minimize and prevent children's exposures to early caregiving adversity, especially in the first years of life. They call for innovative interventions to support neurotypical development in internationally adopted children at elevated risk.

Individual differences in beta frequency correlate with the audio-visual fusion illusion.

Presenting one flash with two beeps induces a perception of two flashes (audio-visual [AV] fission illusion), while presenting two flashes with one beep induces a perception of one flash (fusion illusion). Although previous studies showed a relationship between the frequency of the alpha rhythm (alpha cycle) and one's susceptibility to the fission illusion, the relationship between neural oscillations and the fusion illusion is unknown. Using electroencephalography, here I investigated the frequency of oscillatory signals in the pre-stimulus period and found a significant correlation between the beta rhythm and the fusion illusion; specifically, participants with a lower beta frequency showed a larger fusion illusion. These data indicate two separate time windows of AV integration in the human brain, one defined by the alpha cycle (fission) and another defined by the beta cycle (fusion).

Young-onset diabetes in Asian Indians is associated with lower measured and genetically determined beta cell function

Aims/hypothesisSouth Asians in general, and Asian Indians in particular, have higher risk of type 2 diabetes compared with white Europeans, and a younger age of onset. The reasons for the younger age of onset in relation to obesity, beta cell function and insulin sensitivity are under-explored.MethodsTwo cohorts of Asian Indians, the ICMR-INDIAB cohort (Indian Council of Medical Research-India Diabetes Study) and the DMDSC cohort (Dr Mohan’s Diabetes Specialties Centre), and one of white Europeans, the ESDC (East Scotland Diabetes Cohort), were used. Using a cross-sectional design, we examined the comparative prevalence of healthy, overweight and obese participants with young-onset diabetes, classified according to their BMI. We explored the role of clinically measured beta cell function in diabetes onset in Asian Indians. Finally, the comparative distribution of a partitioned polygenic score (pPS) for risk of diabetes due to poor beta cell function was examined. Replication of the genetic findings was sought using data from the UK Biobank.ResultsThe prevalence of young-onset diabetes with normal BMI was 9.3% amongst white Europeans and 24–39% amongst Asian Indians. In Asian Indians with young-onset diabetes, after adjustment for family history of type 2 diabetes, sex, insulin sensitivity and HDL-cholesterol, stimulated C-peptide was 492 pmol/ml (IQR 353–616, p<0.0001) lower in lean compared with obese individuals. Asian Indians in our study, and South Asians from the UK Biobank, had a higher number of risk alleles than white Europeans. After weighting the pPS for beta cell function, Asian Indians have lower genetically determined beta cell function than white Europeans (p<0.0001). The pPS was associated with age of diagnosis in Asian Indians but not in white Europeans. The pPS explained 2% of the variation in clinically measured beta cell function, and 1.2%, 0.97%, and 0.36% of variance in age of diabetes amongst Asian Indians with normal BMI, or classified as overweight and obese BMI, respectively.Conclusions/interpretationThe prevalence of lean BMI in young-onset diabetes is over two times higher in Asian Indians compared with white Europeans. This phenotype of lean, young-onset diabetes appears driven in part by lower beta cell function. We demonstrate that Asian Indians with diabetes also have lower genetically determined beta cell function.Graphical abstract

Exploring psychophysiological indices of disruptive behavior disorders and their subtypes of aggression

BackgroundPsychophysiological measures of arousal are often considered as potential biomarkers for disruptive behavior disorder (DBD). Nevertheless, the evidence is mixed, possibly reflecting the heterogeneity of DBD and different subtypes of aggression. Additionally, arousal measures of the central nervous system (e.g. electroencephalogram: EEG) are underrepresented compared to peripheral ones (heart rate: HR; skin conductance: SC). MethodsWe recorded HR, SC, and EEG (frequency band power at three electrodes Fz, Cz, Pz) in 49 participants with DBD, and 15 typically developing peers during two resting state and an emotional task condition. Group differences were assessed by a repeated measure ANOVA and regression analyses were applied to evaluate subtype-specific patterns. ResultsOur results showed higher mean HR activity in DBD participants, which was however driven by medicated participants and no significant group differences were found for SC. Interestingly, a significant group x frequency band interaction emerged for the EEG. DBD youth showed lower alpha activity. Regression analyses showed that higher theta and lower alpha band activity were related to more general aggression scores and higher delta and lower beta activity predicted proactive aggression. ConclusionsThe lack of robust and significant differences for peripheral measurements (HR and SC) fits with previous mixed findings for externalizing disorders. Our results suggest that EEG measurements might be more sensitive to detect group differences and higher delta and lower beta activity might represent an index of a proactive subtype of aggression.

Political Beta

Abstract Using a portfolio theory framework, we introduce the concept of “political beta” to model firm-level export diversification in response to global political risk. Our model predicts that firms are less responsive to changes in political relations with lower beta countries—those that contribute less to the firm’s total political risk. We document patterns consistent with our model using disaggregated Russian firm-by-destination-country data during 2001–2011: Trade is positively correlated with political relations, though the effect is far weaker for trading partners whose political relations with Russia are relatively uncorrelated with those of other partners in a firm’s export portfolio.

Brain oscillatory patterns in mild cognitive impairment due to Alzheimer’s and Parkinson’s disease: An exploratory high-density EEG study

ObjectiveWe investigated brain cortical activity alterations, using a resting-state 256-channel high-density EEG (hd-EEG), in Alzheimer’s (AD) and Parkinson’s (PD) disease subjects with mild cognitive impairment (MCI) and correlations between quantitative spectral EEG parameters and the global cognitive status assessed by Montreal Cognitive Assessment (MoCA) score. MethodsFifteen AD-MCI, eleven PD-MCI and ten age-matched healthy-controls (HC) underwent hd-EEG recordings and neuropsychological assessment. Cerebrospinal fluid biomarker analysis was performed to obtain well-characterized groups. EEG spectral features were extracted and the differences between the three groups, as well as correlations with MoCA, were investigated. ResultsThe results showed significantly lower alpha2 power and alpha2/alpha1 ratio in both AD-MCI and PD-MCI compared to controls. The significantly higher theta and lower beta power and alpha/theta ratio were observed in PD-MCI compared to AD-MCI and HC. MoCA score correlated inversely with theta power and directly with alpha2 and beta powers, as well as with alpha2/alpha1 and alpha/theta ratios. ConclusionsThis study highlighted significant differences in EEG patterns in AD-MCI and PD-MCI patients and remarked the role of EEG parameters as possible surrogate markers of cognitive status in both neurodegenerative diseases. SignificanceIn addition to well-established biomarkers, our findings could support early detection of cognitive dysfunction in neurodegenerative disorders and could help to monitor disease progression and therapeutic responses.

Conserving alpha and beta diversity in wood-production landscapes.

International demand for wood and other forest products continues to grow rapidly, and uncertainties remain about how animal communities will respond to intensifying resource extraction associated with woody bioenergy production. We examined changes in alpha and beta diversity of bats, bees, birds, and reptiles across wood production landscapes in the southeastern United States, a biodiversity hotspot that is one of the principal sources of woody biomass globally. We sampled across a spatial gradient of paired forest land-uses (representing pre and postharvest) that allowed us to evaluate biological community changes resulting from several types of biomass harvest. Short-rotation practices and residue removal following clearcuts were associated with reduced alpha diversity (-14.1 and -13.9 species, respectively) and lower beta diversity (i.e., Jaccard dissimilarity) between land-use pairs (0.46 and 0.50, respectively), whereas midrotation thinning increased alpha (+3.5 species) and beta diversity (0.59). Over the course of a stand rotation in a single location, biomass harvesting generally led to less biodiversity. Cross-taxa responses to resource extraction were poorly predicted by alpha diversity: correlations in responses between taxonomic groups were highly variable (-0.2 to 0.4) with large uncertainties. In contrast, beta diversity patterns were highly consistent and predictable across taxa, where correlations in responses between taxonomic groups were all positive (0.05-0.4) with more narrow uncertainties. Beta diversity may, therefore, be a more reliable and information-rich indicator than alpha diversity in understanding animal community response to landscape change. Patterns in beta diversity were primarily driven by turnover instead of species loss or gain, indicating that wood extraction generates habitats that support different biological communities.

People With Parkinson's Disease and Freezing of Gait Show Abnormal Low Frequency Activity of Antagonistic Leg Muscles.

ObjectiveFreezing of gait is detrimental to patients with idiopathic Parkinson’s disease (PD). Its pathophysiology represents a multilevel failure of motor processing in the cortical, subcortical, and brainstem circuits, ultimately resulting in ineffective motor output of the spinal pattern generator. Electrophysiological studies pointed to abnormalities of oscillatory activity in freezers that covered a broad frequency range including the theta, alpha, and beta bands. We explored muscular frequency domain activity with respect to freezing, and used deep brain stimulation to modulate these rhythms thereby evaluating the supraspinal contributions to spinal motor neuron activity.MethodsWe analyzed 9 PD freezers and 16 healthy controls (HC). We studied the patients after overnight withdrawal of dopaminergic medication with stimulation off, stimulation of the subthalamic nucleus (STN-DBSonly) or the substantia nigra pars reticulate (SNr-DBSonly), respectively. Patients performed a walking paradigm passing a narrow obstacle. We analyzed the frequency-domain spectra of the tibialis anterior (TA) and gastrocnemius (GA) muscles in ‘regular gait’ and during the ‘freezing’ episodes.ResultsIn stimulation off, PD freezers showed increased muscle activity of the alpha and low-beta band compared to HC in both TA and GA. This activity increase was present during straight walking and during the freezes to similar extent. STN- but not SNr-DBS decreased this activity and paralleled the clinical improvement of freezing.ConclusionWe found increased muscle activation of the alpha and lower beta band in PD freezers compared to HC, and this was attenuated with STN-DBS. Future studies may use combined recordings of local field potentials, electroencephalography (EEG), and electromyography (EMG) to interrogate the supraspinal circuit mechanisms of the pathological activation pattern of the spinal pattern generator.

Differences in gut microbiome by insulin sensitivity status in Black and White women of the National Growth and Health Study (NGHS): A pilot study.

The prevalence of overweight and obesity is greatest amongst Black women in the U.S., contributing to disproportionately higher type 2 diabetes prevalence compared to White women. Insulin resistance, independent of body mass index, tends to be greater in Black compared to White women, yet the mechanisms to explain these differences are not completely understood. The gut microbiome is implicated in the pathophysiology of obesity, insulin resistance and cardiometabolic disease. Only two studies have examined race differences in Black and White women, however none characterizing the gut microbiome based on insulin sensitivity by race and sex. Our objective was to determine if gut microbiome profiles differ between Black and White women and if so, determine if these race differences persisted when accounting for insulin sensitivity status. In a pilot cross-sectional analysis, we measured the relative abundance of bacteria in fecal samples collected from a subset of 168 Black (n = 94) and White (n = 74) women of the National Growth and Health Study (NGHS). We conducted analyses by self-identified race and by race plus insulin sensitivity status (e.g. insulin sensitive versus insulin resistant as determined by HOMA-IR). A greater proportion of Black women were classified as IR (50%) compared to White women (30%). Alpha diversity did not differ by race nor by race and insulin sensitivity status. Beta diversity at the family level was significantly different by race (p = 0.033) and by the combination of race plus insulin sensitivity (p = 0.038). Black women, regardless of insulin sensitivity, had a greater relative abundance of the phylum Actinobacteria (p = 0.003), compared to White women. There was an interaction between race and insulin sensitivity for Verrucomicrobia (p = 0.008), where among those with insulin resistance, Black women had four fold higher abundance than White women. At the family level, we observed significant interactions between race and insulin sensitivity for Lachnospiraceae (p = 0.007) and Clostridiales Family XIII (p = 0.01). Our findings suggest that the gut microbiome, particularly lower beta diversity and greater Actinobacteria, one of the most abundant species, may play an important role in driving cardiometabolic health disparities of Black women, indicating an influence of social and environmental factors on the gut microbiome.