Low Beta Research Articles

Sleep associated electrophysiological activity in subjects at different levels of risk of developing Alzheimer’s disease

AbstractBackgroundAlzheimer’s disease (AD) is tightly associated with sleep alterations: as the disease progresses, sleep quality worsens. Therefore, the study of sleep patterns in interaction with other variables could constitute an early biomarker of AD. It is widely known that sleep alterations lead to an impaired cognitive functioning and performance, and recent studies evidence a positive feedback between amyloid beta (AB) accumulation and sleep. Consequently, sleep could constitute an interesting target for interventions aimed at altering the course of the disease. In the present study, we studied the relationship between self‐reported measures of sleep quality (i.e. number of hours of sleep) and the electrophysiological activity at resting‐state recorded using magnetoencephalography (MEG).MethodThe sample for this study was composed of healthy adults, with varying risks of developing AD (direct relatives vs non‐relatives, and APOE‐E4 carriers vs non‐carriers). All participants completed the Pittsburgh Sleep Quality Index, underwent a MEG scan, and were genotyped for their APOE carriage.ResultPreliminary results show different patterns of brain activation in areas classically associated with the development of AD, in relatives and non‐relatives, in relation with the number of hours of sleep. Non‐relatives present a significant cluster that encompases areas such as the precuneus, where a positive correlation is found between the power in the low beta (12‐20Hz) frequency band and the number of hours of sleep. Relatives do not show clusters where relative power and hours of sleep correlate significantly.ConclusionAlthough further research is needed, a possible interpretation of these results could be the following: non‐relatives’ brain functioning in areas of the default‐mode network, typically associated with AD, are more affected by the number of hours of sleep than relatives, who may not benefit as much due to early damage interfering with the protective effect of sleep.

Developments in Transcranial Magnetic Stimulation to Study Human Cognition.

Developments in Transcranial Magnetic Stimulation to Study Human Cognition.

Presidential economic approval rating and the cross-section of stock returns

We construct a monthly presidential economic approval rating (PEAR) index from 1981 to 2019, by averaging ratings on the president’s handling of the economy across various national polls. In the cross-section, stocks with high betas to changes in the PEAR index significantly under-perform those with low betas by 1.00% per month in the future, on a risk-adjusted basis. The low PEAR beta premium persists up to one year, and is present in various sub-samples and even in other G7 countries. PEAR beta dynamically reveals a firm’s perceived alignment to the incumbent president’s economic policies and investors seem to misprice such an alignment.

Motor event-related synchronization as an inhibitory biomarker of pain severity, sensitivity, and chronicity in patients with knee osteoarthritis

ObjectiveThe study aimed to examine the clinical and neurophysiological predictors of motor event-related desynchronization (ERD) and synchronization (ERS) in patients with chronic pain due to knee osteoarthritis (KOA). MethodsWe performed a cross-sectional analysis of our cohort study (DEFINE cohort), KOA arm, with 71 patients, including demographic, functionality, genetic and neurophysiological measures. ERD/ERS was evaluated during hand motor tasks (motor execution, active and passive observation, and imagery). Multivariate regression models were used to explore predictors of ERD/ERS. ResultsAlthough we found an altered ERD/ERS pattern during motor execution and active observation, the ERS pattern could only be clearly differentiated after passive observation.`. We found no predictors of ERD (excitatory biomarker). For ERS (inhibitory biomarker), our results showed that the main predictors differ across EEG frequency bands. Considering pain measures, we found that visual analogue scale (VAS, right knee) and chronicity of pain negatively predict low beta and high beta ERS, respectively. Pain threshold was positively correlated with alpha ERS, while 36-Item Short Form Survey (SF-36) emotional domain positively predicted beta ERS. Regarding transcranial magnetic stimulation (TMS) markers, intracortical inhibition (ICF) negatively predicted beta and low beta ERS, and left hemisphere cortical silent period (CSP) negatively predicted low beta ERS. ConclusionConsidering that higher power of ERS indicates a stronger cortical organization and inhibitory drive, our results show that limitation of activities due to emotional factors, lower pain threshold, higher VAS pain, and longer duration of pain are associated with lower ERS power (in alpha and beta frequencies), thus indicating a lower inhibitory drive. In the same direction, a lower inhibitory drive as indicated by higher ERS power is associated with higher ICF amplitude. Although there was a negative association between ERS and CSP, this may indicate that ICF values are adjusting CSP results. Our findings support the idea that a less organized cortical response as indicated by changes to the ERS is associated with higher pain correlates in subjects with KOA.

PMON313 Hyperinsulinemic Hypoglycemia and Growth Hormone Deficiency Secondary to 20p11 Deletion

Abstract Introduction Hyperinsulinism (HI) and growth hormone deficiency (GHD) are known causes of hypoglycemia but not commonly found together. We present a 4-month-old boy with hypoglycemia found to have both HI and GHD with subsequent genetic diagnosis of 20p11 deletion. This deletion has been associated with panhypopituitarism. This case represents a few to report HI as a manifestation of this deletion. Treatment with both recombinant human growth hormone (rhGH) and Diazoxide led to blood glucose (BG) normalization. Clinical Case A 4-month-old, full-term, large for gestational age (96th percentile), born to a nondiabetic mother presented with hypoglycemic seizures. He had transient hypoglycemia at birth, normal newborn screen, and exclusively breastfeeding with normal growth and development. He had a negative 60-hour video EEG. Further work-up was significant for serum glucose of 54 mg/dL despite blood draw being 20 minutes after a breastfeed, prompting endocrinology evaluation. Physical exam showed no dysmorphism and normal genitalia. He had a serum glucose of 39 mg/dL while asymptomatic. Critical sample revealed detectable insulin (3.2 mcIU/mL), low beta hydroxybutyrate (145.6 mcmol/L) and low growth hormone (GH) (4.2 ng/dL). He had normal cortisol, lactic acid and ammonia. A glucagon challenge showed an increase in BG of 26 mg/dL (35-->61 mg/dL). He had a GH stimulation test with arginine (peak GH 3.8 ng/dL) and glucagon (peak GH 6.6 ng/dL). He had mildly elevated liver enzymes that resolved on repeat testing. Plasma amino acid, plasma acylcarnitine profile, urine organic acids, and brain MRI were normal. He was initially started on rhGH with continued hypoglycemia, hence, Diazoxide, and chlorothiazide were added. His BG was monitored until dextrose infusion was successfully weaned, while maintaining normoglycemia. Genetic testing with next-generation sequencing revealed 20p11.22-p11.21 deletion. He was discharged on Diazoxide (12 mg/kg/day), chlorothiazide, and rhGH (0.27 mg/kg/week). Conclusion It is important to determine the cause of hypoglycemia so specific treatment can be provided. HI is a common cause of hypoglycemia in infants due to abnormal insulin secretion in the pancreatic beta cells. GHD can also cause hypoglycemia and be associated with other pituitary hormone deficiencies. Evaluation of our patient's hypoglycemia revealed HI, GHD and 20p11 deletion. This deletion has been associated with hypoglycemia due to GHD and few reports with HI. This patient will need to be regularly screened for other pituitary hormone abnormalities. Other features of 20p11 deletion include cognitive delay, craniofacial dysmorphisms, gastrointestinal and genitourinary anomalies. While hypoglycemia is often the result of a single cause, this case shows that there are pathological conditions that can present with both GHD and HI, so the differential diagnosis for hypoglycemia should remain broad. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

PSAT277 Glucocorticoid Therapy for Management of Hypoglycemia in the context of Non-Islet Cell Tumor-Induced Hypoglycemia

Abstract Background Non-islet cell tumor-induced hypoglycemia (NICTH) is a rare paraneoplastic syndrome which can cause recurrent hypoglycemia. There is no clear standard of care for management of hypoglycemia. Often, these patients have high morbidity and therefore surgical tumor resection is not always possible. Clinical case: This is the case of a 69 year-old male presenting with altered mental status in the context of hypoglycemia without clear etiology with an initial serum glucose level of 32 mg/dL (normal range 60-100 mg/dL) which quickly corrected after administration of intravenous glucose. He was found to have a large bowel obstruction with CT abdomen revealing an underlying neoplasm. Biopsy of suspected lesion on colonoscopy revealed colorectal adenocarcinoma. Repeated episodes of hypoglycemia complicated by seizures required inpatient management. Workup included serum insulin level which resulted in suppressed level (<1. 0 uU/mL, normal range 1.9-23. 0 uU/mL), low c-peptide level (0.1 ng/mL, normal range 1.1-4.4 ng/mL), low beta hydroxybutyrate level (0. 07 mmol/L, normal level <0.3 mmol/L), cortisol level of 43.7 mcg/dL, undetectable insulin like growth factor-1 (IGF-1) level (<10 ng/mL, normal range 59-230 ng/mL) and low insulin like growth factor-2 (IGF-2) level (66 ng/mL, normal range 333 - 967 ng/mL). IGF2: IGF1 ratio was 66 (ratio >10 is indicative for diagnosis of non-islet cell tumor hypoglycemia). Due to extremely poor oral intake and recurrent episodes of hypoglycemia despite continuous dextrose infusion, the patient was started on 20 mg prednisone daily. Eventually, 40 mg of intravenous methylprednisolone in addition to dextrose infusion was needed as maintenance therapy effectively preventing hypoglycemia. Given his poor functional status, the surgical and oncology team decided he was no longer a surgical or chemotherapy candidate. Eventually, palliative medicine was consulted and the patient was transitioned to comfort care with a plan for outpatient hospice. Conclusion NICTH should be suspected in any patient with hypoglycemia without clear etiology, especially if there are suggestions to NICTH such as known malignancy or newly diagnosed mass. Once NICTH is identified and a primary tumor is found, complete tumor resection represents ideal management, however, not always attainable. In such cases, dextrose infusion might be insufficient to prevent hypoglycemia and is not always the preferred option given the required long-term venous access. In these circumstances, early high dose glucocorticoids are safe and appear to successfully prevent hypoglycemic events. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Changes in the Treatment of Decompensated Advanced Heart Failure During Hospitalization and at Discharge

In advanced heart failure (HF), each hospitalization for decompensation is a vulnerable moment, and it requires optimizing pharmacologic treatment. This study aimed to analyze changes in the pharmacologic treatment of HF before admission (P), during hospitalization (H), and at discharge (D) of patients with decompensated advanced HF. We performed an ambispective, cross-sectional, noninterventional study conducted from January 2020 to June 2020. There were 252 consecutive patients admitted for decompensated advanced HF. The following were excluded: de novo HF cases, deceased patients, and scheduled admissions. Finally, 134 patients were analyzed, compared in 3 subgroups: pulmonary congestion (n=90), systemic congestion (n=31), and low output (n=13). In the global analysis, an increase was detected in angiotensin receptor and neprilysin inhibitors (P: 9.7%, H: 16.4, D: 22.4%; P < .02), beta blockers (P: 67.2%, H: 77.6%, D: 84.3%; P < .004), mineralocorticoid receptor antagonists (P: 29.9%, H: 44.4%, D: 46.3%; P < .01), loop diuretics (P: 70.1%, H: 99.3%, D: 95.5%; P < .001), and nitrates (P: 6.0%, H: 22.4%, D: 9.7%; P < .001). Pulmonary congestion was predominant with a significant increase in beta blockers (P: 61.1%, H: 77.8%, D: 88.9%; P < .001) and loop diuretics (P: 64.4%, H: 100%, D: 100%; P < .001); diuretics were increased in the systemic congestion group (P: 80.6%, H: 100%, D: 100%; P < .002), and 22.6% required 3% hypertonic saline solution. In patients with low output, beta blockers and diuretics were withdrawn (P: 84.6%, H: 76.9%, D: 46.1%; P < .08 and P: 84.6%, H: 92.3%, D: 61.5%; P < .1 respectively), without variation in the other pharmacologic groups. In daily clinical practice, HF drugs are increased and optimized in decompensated HF with a pulmonary or systemic congestion profile. When the profile is low output, beta blockers and diuretics are reduced.

Electroencephalographic oscillations of alpha and beta rhythms during phrase-guessing procedure.

Phrases-guessing is one of the essential reasoning abilities in problem solving for human beings. However, it is still an open question about why individuals perform differently during the same reasoning task. In this study, we utilized a bilingual phrase-guessing task to explore the neural activities under the individually different performances with electroencephalography. Participants who had no knowledge of Greek were required to guess the meaning of a Greek phrase (long or short in length) by making an either-or selection as to which translation-equivalent Chinese word corresponds to Greek word. Names of color were used as experimental stimuli for which two Chinese words denoted the same color with one as a conventional color name and the other as a novel color name. The experiment yielded length of phrases (long vs. short) and novelty of phrases (novel vs. conventional) as variables. The behavioral results revealed significant length-by-novelty interaction on the number of selections. However, neither main effects nor interactive effects were found on response time. Further, the amplitude spectrums of high alpha rhythm, low alpha rhythm, and low beta rhythm during the task were positively associated with the participants' number of selections for a long Greek phrase with a novel and complex Chinese phrase (LNc) and a short Greek phrase with a conventional Chinese phrase (SCo), while negatively correlated with the response time of selections for LNc and SCo. Our findings suggested that the consistency between participants' behavior and electrophysiological oscillations (alpha and beta bands) could be employed as biomarkers for decoding the phrase-guessing procedure.

Large-scale frontoparietal theta, alpha, and beta phase synchronization: A set of EEG differential characteristics for freezing of gait in Parkinson’s disease?

Freezing of gait (FOG) is a complex gait disturbance in Parkinson's disease (PD), during which the patient is not able to effectively initiate gait or continue walking. The mystery of the FOG phenomenon is still unsolved. Recent studies have revealed abnormalities in cortical activities associated with FOG, which highlights the importance of cortical and cortical-subcortical network dysfunction in PD patients with FOG. In this paper, phase-locking value (PLV) of eight frequency sub-bands between 0.05 Hz and 35 Hz over frontal, motor, and parietal areas [during an ankle dorsiflexion (ADF) task] is used to investigate EEG phase synchronization. PLV was investigated over both superficial and deeper networks by analyzing EEG signals preprocessed with and without Surface Laplacian (SL) spatial filter. Four groups of participants were included: PD patients with severe FOG (N = 5, 5 males), PD patients with mild FOG (N = 7, 6 males), PD patients without FOG (N = 14, 13 males), and healthy age-matched controls (N = 13, 10 males). Fifteen trials were recorded from each participant. At superficial layers, frontoparietal theta phase synchrony was a unique feature present in PD with FOG groups. At deeper networks, significant dominance of interhemispheric frontoparietal alpha phase synchrony in PD with FOG, in contrast to beta phase synchrony in PD without FOG, was identified. Alpha phase synchrony was more distributed in PD with severe FOG, with higher levels of frontoparietal alpha phase synchrony. In addition to FOG-related abnormalities in PLV analysis, phase-amplitude coupling (PAC) analysis was also performed on frequency bands with PLV abnormalities. PAC analysis revealed abnormal coupling between theta and low beta frequency bands in PD with severe FOG at the superficial layers over frontal areas. At deeper networks, theta and alpha frequency bands show high PAC over parietal areas in PD with severe FOG. Alpha and low beta also presented PAC over frontal areas in PD groups with FOG. The results introduced significant phase synchrony differences between PD with and without FOG and provided important insight into a possible unified underlying mechanism for FOG. These results thus suggest that PLV and PAC can potentially be used as EEG-based biomarkers for FOG.

A quantitative model reveals a frequency ordering of prediction and prediction-error signals in the human brain

The human brain is proposed to harbor a hierarchical predictive coding neuronal network underlying perception, cognition, and action. In support of this theory, feedforward signals for prediction error have been reported. However, the identification of feedback prediction signals has been elusive due to their causal entanglement with prediction-error signals. Here, we use a quantitative model to decompose these signals in electroencephalography during an auditory task, and identify their spatio-spectral-temporal signatures across two functional hierarchies. Two prediction signals are identified in the period prior to the sensory input: a low-level signal representing the tone-to-tone transition in the high beta frequency band, and a high-level signal for the multi-tone sequence structure in the low beta band. Subsequently, prediction-error signals dependent on the prior predictions are found in the gamma band. Our findings reveal a frequency ordering of prediction signals and their hierarchical interactions with prediction-error signals supporting predictive coding theory.

Designing a 176 MHz Superconducting Half-Wave Resonator for SARAF-Phase II—Studies and Results

In 2014, Commissariat à l'Energie Atomique et aux Energies Alternatives (Saclay, France) launched the studies to deliver a superconducting linac (SCL) for SARAF-Phase II accelerator in order to accelerate a 5-mA beam of either protons from 1.3 to 35 MeV or deuterons from 2.6 to 40 MeV. The SCL consists of four cryomodules. The first two cryomodules will host six and seven half-wave resonator (HWR) low beta cavities (beta = 0.09) at 176 MHz. The last two cryomodules will host seven HWR high-beta cavities (beta = 0.18) at the same frequency. The prototypes were qualified in 2019 and 2021. The series manufacturing is ongoing. This article presents the design steps of these cavities, at the very beginning of the project, and presents results for prototypes and series.

EEG signal processing by feature extraction and classification based on biomedical deep learning architecture with wireless communication

The brain is the most important organ in the human body. It transmits a lot of data to many body parts and its health is a prominent topic in e-healthcare. The Electroencefalography (EEG) is used in the biomedical industry to identify brain-related illnesses in which the input was gathered via brain EEG waves to extract brain action features. The band power of each collected signal is seen in Emotive Epoc Pro. Alpha wave (4–8 Hz), theta wave The recorded signal's changes with respect to time are at the frequencies of (4–8 Hz), alpha (8–12 Hz), low beta (12–16 Hz), beta (16–25 Hz), and gamma (25–45 Hz). The kernel extreme learning-based multilayer perceptron (KExL MLP) was used to extract the processed images and the extracted features of brain activity have been classified using Bayesian quadratic discriminant Transfer neural network (BQDTNN) which reflect brain activity. The accuracy of the parametric analysis was 96 %, the precision was 72 %, the recall was 69 %, and the F-1 score was 62 % for the EEG input dataset and 98 %, the precision was 80%, the recall was 73 %, and the F-1 score was 71 % for the SSVEP EEG dataset.

Determinan Struktur Modal: Perspektif Pecking Order Theory dan Trade-off Theory

This study aims to determine how much influence the asset structure, non-debt tax shields, firm size and profitability have on the capital structure of the Food and Baverages Sub-Sector Companies listed on the Indonesia Stock Exchange. The method used in this study is a quantitative method. The data analysis technique used in this research is multiple regression analysis. Asset structure has a positive and significant impact on the capital structure of companies listed in the Food and Beverage Industry Sector on the IDX for the 2014-2018 period. With the value of the beta coefficient included in the low category, the results of this study are in accordance with the Trade-off theory. Non-debt tax shields have no significant effect on the capital structure of companies listed in the Food and Beverage Industry Sector on the IDX for the 2014-2018 period. With the value of the beta coefficient being very low, the results of this study are not in accordance with the trade-off theory. Firm size has a significant effect on the capital structure of companies listed in the Food and Beverage Industry Sector on the IDX for the 2014-2018 period. With a low beta coefficient value. The results of this study are not in accordance with the pecking order theory. Profitability has a positive and significant effect on the capital structure of companies in the Food and Beverage Industry Sector Listing on the IDX for the 2014-2018 period. With the value of the beta coefficient is included in the low category. The results of this study are in accordance with the pecking order theory.

What are the fundamental modes of energy transfer and partitioning in the coupled Magnetosphere-Ionosphere system?

The fundamental processes responsible for energy exchange between large-scale electromagnetic fields and plasma are well understood theoretically, but in practice these theories have not been tested. These processes are ubiquitous in all plasmas, especially at the interface between high and low beta plasmas in planetary magnetospheres and other magnetic environments. Although such boundaries pervade the plasma Universe, the processes responsible for the release of the stored magnetic and thermal plasma energy have not been fully identified and the importance of the relative impact of each process is unknown. Despite advances in understanding energy release through the conversion of magnetic to kinetic energy in magnetic reconnection, how the extreme pressures in the regions between stretched and more relaxed field lines in the transition region are balanced and released through adiabatic convection of plasma and fields is still a mystery. Recent theoretical advances and the predictions of large-scale instabilities must be tested. In essence, the processes responsible remain poorly understood and the problem unresolved. The aim of the White Paper submitted to ESA’s Voyage 2050 call, and the contents of this paper, is to highlight three outstanding open science questions that are of clear international interest: (i) the interplay of local and global plasma physics processes: (ii) the partitioning during energy conversion between electromagnetic and plasma energy: and (iii) what processes drive the coupling between low and high beta plasmas. We present a discussion of the new measurements and technological advances required from current state-of-the-art, and several candidate mission profiles with which these international high-priority science goals could be significantly advanced.

Unexpected diversity found within benthic microbial mats at hydrothermal springs in Crater Lake, Oregon.

Crater Lake, Oregon is an oligotrophic freshwater caldera lake fed by thermally and chemically enriched hydrothermal springs. These vents distinguish Crater Lake from other freshwater systems and provide a unique ecosystem for study. This study examines the community structure of benthic microbial mats occurring with Crater Lake hydrothermal springs. Small subunit rRNA gene amplicon sequencing from eight bacterial mats was used to assess community structure. These revealed a relatively homogeneous, yet diverse bacterial community. High alpha diversity and low beta diversity indicate that these communities are likely fueled by homogeneous hydrothermal fluids. An examination of autotrophic taxa abundance indicates the potential importance of iron and sulfur inputs to the primary productivity of these mats. Chemoautotrophic potential within the mats was dominated by iron oxidation from Gallionella and Mariprofundus and by sulfur oxidation from Sulfuricurvum and Thiobacillus with an additional contribution of nitrite oxidation from Nitrospira. Metagenomic analysis showed that cbbM genes were identified as Gallionella and that aclB genes were identified as Nitrospira, further supporting these taxa as autotrophic drivers of the community. The detection of several taxa containing arsC and nirK genes suggests that arsenic detoxification and denitrification processes are likely co-occurring in addition to at least two modes of carbon fixation. These data link the importance of the detected autotrophic metabolisms driven by fluids derived from benthic hydrothermal springs to Crater Lake’s entire lentic ecosystem.

Peri-lead edema and local field potential correlation in post-surgery subthalamic nucleus deep brain stimulation patients.

Implanting deep brain stimulation (DBS) electrodes in patients with Parkinson’s disease often results in the appearance of a non-infectious, delayed-onset edema that disappears over time. However, the time window between the DBS electrode and DBS stimulating device implant is often used to record local field potentials (LFPs) which are used both to better understand basal ganglia pathophysiology and to improve DBS therapy. In this work, we investigated whether the presence of post-surgery edema correlates with the quality of LFP recordings in eight patients with advanced Parkinson’s disease implanted with subthalamic DBS electrodes. The magnetic resonance scans of the brain after 8.5 ± 1.5 days from the implantation surgery were segmented and the peri-electrode edema volume was calculated for both brain hemispheres. We found a correlation (ρ = −0.81, p < 0.0218, Spearman’s correlation coefficient) between left side local field potentials of the low beta band (11–20 Hz) and the edema volume of the same side. No other significant differences between the hemispheres were found. Despite the limited sample size, our results suggest that the effect on LFPs may be related to the edema localization, thus indicating a mechanism involving brain networks instead of a simple change in the electrode-tissue interface.

Shaping Information Processing: The Role of Oscillatory Dynamics in a Working Memory Task.

Neural oscillations are thought to reflect low-level operations that can be used for higher-level cognitive functions. Here, we investigated the role of brain rhythms in the 1–30 Hz range by recording MEG in human participants performing a visual delayed match-to-sample paradigm in which orientation or spatial frequency of sample and probe gratings had to be matched. A cue occurring before or after sample presentation indicated the to-be-matched feature. We demonstrate that alpha/beta power decrease tracks the presentation of the informative cue and indexes faster responses. Moreover, these faster responses coincided with an augmented phase alignment of slow oscillations, as well as phase–amplitude coupling between slow and fast oscillations. Importantly, stimulus decodability was boosted by both low alpha power and high beta power. In summary, we provide support for a comprehensive framework in which different rhythms play specific roles: slow rhythms control input sampling, while alpha (and beta) gates the information flow, beta recruits task-relevant circuits, and the timing of faster oscillations is controlled by slower ones.

Index tracking and beta arbitrage effects in comovement

This paper develops a stylised model for S&P 500 index changes with two beta-based styles: index trackers and beta arbitrageurs who trade in both high and low beta event stocks to exploit mean reversion towards one. Arbitrageurs engage in common or contrarian trading patterns relative to index funds depending on whether historical betas are below or above one. Thus, the overall comovement effect has two distinct components. After index additions, pre-event low beta stocks drive the overall beta increases due to common demand – albeit for different reasons - from indexers and arbitrageurs. By contrast, arbitrageur shorting of high beta additions diminishes or sometimes reverses the beta increases for these stocks driven by indexers. Analogous results hold for index deletions.

Climate change news sensitivity and mutual fund performance

In the presence of rising concern about climate change that potentially affects risk and return of investors' portfolio companies, active investors might have dispersed climate change risk exposures. We compute mutual fund covariance with market-wide climate change news index and find that high (positive) climate news beta funds outperform low (negative) climate news beta funds by 0.24% per month on a risk-adjusted basis. High climate news beta funds tilt their holdings toward stocks with high potential to hedge against climate change news risk. In the cross section, such stocks yield higher excess returns, which are driven by greater pricing pressure and superior financial performance over our sample period.

Neutrino Mass Measurements Using Cryogenic Detectors

The determination of the absolute mass scale of neutrinos is one of the most important challenges in Particle Physics. The shape of the endpoint region of beta ^--decay and electron capture (EC) spectra depends on the phase space factor, which, in turn, is function of the masses of the neutrino mass eigenstates. High energy resolution and high statistics measurements of beta ^- and EC spectra are therefore considered a model-independent way for the determination of the neutrino mass scale. Since almost four decades, low temperature microcalorimeters are used for the measurement of low energy beta ^- and EC spectra. The first efforts were focused on the development of large arrays for the measurement of the ^{187}Re beta ^--spectrum. In the last ten years, the attention moved to EC of ^{163}Ho. This choice was mainly motivated by the very good performance which could be achieved with low temperature microcalorimeters enclosing ^{163}Ho with respect to microcalorimeters with absorber containing ^{187}Re. The development of low temperature microcalorimeters for the measurement of the finite neutrino mass is discussed and, in particular, the reasons for moving from ^{187}Re to ^{163}Ho. The possibility to reach sub-eV sensitivity on the effective electron neutrino mass with ^{163}Ho, thanks to the multiplexing of large microcalorimeter arrays is demonstrated. In conclusion, an overview on other nuclides which have been proposed as good candidates, motivated by the excellent performance of low temperature microcalorimeters is presented.