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1.
Nature ; 632(8025): 517-521, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38959958

ABSTRACT

Unconventional quasiparticles emerging in the fractional quantum Hall regime1,2 present the challenge of observing their exotic properties unambiguously. Although the fractional charge of quasiparticles has been demonstrated for nearly three decades3-5, the first convincing evidence of their anyonic quantum statistics has only recently been obtained6,7 and, so far, the so-called scaling dimension that determines the propagation dynamics of the quasiparticles remains elusive. In particular, although the nonlinearity of the tunnelling quasiparticle current should reveal their scaling dimension, the measurements fail to match theory, arguably because this observable is not robust to non-universal complications8-12. Here we expose the scaling dimension from the thermal noise to shot noise crossover and observe an agreement with expectations. Measurements are fitted to the predicted finite-temperature expression involving both the scaling dimension of the quasiparticles and their charge12,13, in contrast to previous charge investigations focusing on the high-bias shot-noise regime14. A systematic analysis, repeated on several constrictions and experimental conditions, consistently matches the theoretical scaling dimensions for the fractional quasiparticles emerging at filling factors ν = 1/3, 2/5 and 2/3. This establishes a central property of fractional quantum Hall anyons and demonstrates a powerful and complementary window into exotic quasiparticles.

2.
Am J Hum Genet ; 110(3): 516-530, 2023 03 02.
Article in English | MEDLINE | ID: mdl-36796361

ABSTRACT

Primate-specific genes (PSGs) tend to be expressed in the brain and testis. This phenomenon is consistent with brain evolution in primates but is seemingly contradictory to the similarity of spermatogenesis among mammals. Here, using whole-exome sequencing, we identified deleterious variants of X-linked SSX1 in six unrelated men with asthenoteratozoospermia. SSX1 is a PSG expressed predominantly in the testis, and the SSX family evolutionarily expanded independently in rodents and primates. As the mouse model could not be used for studying SSX1, we used a non-human primate model and tree shrews, which are phylogenetically similar to primates, to knock down (KD) Ssx1 expression in the testes. Consistent with the phenotype observed in humans, both Ssx1-KD models exhibited a reduced sperm motility and abnormal sperm morphology. Further, RNA sequencing indicated that Ssx1 deficiency influenced multiple biological processes during spermatogenesis. Collectively, our experimental observations in humans and cynomolgus monkey and tree shrew models highlight the crucial role of SSX1 in spermatogenesis. Notably, three of the five couples who underwent intra-cytoplasmic sperm injection treatment achieved a successful pregnancy. This study provides important guidance for genetic counseling and clinical diagnosis and, significantly, describes the approaches for elucidating the functions of testis-enriched PSGs in spermatogenesis.


Subject(s)
Asthenozoospermia , Tupaia , Animals , Male , Macaca fascicularis , Primates , Semen , Sperm Motility , Tupaiidae
3.
J Neurosci ; 44(6)2024 Feb 07.
Article in English | MEDLINE | ID: mdl-37968120

ABSTRACT

In higher sensory brain regions, slow oscillations (0.5-5 Hz) associated with quiet wakefulness and attention modulate multisensory integration, predictive coding, and perception. Although often assumed to originate via thalamocortical mechanisms, the extent to which subcortical sensory pathways are independently capable of slow oscillatory activity is unclear. We find that in the first station for auditory processing, the cochlear nucleus, fusiform cells from juvenile mice (of either sex) generate robust 1-2 Hz oscillations in membrane potential and exhibit electrical resonance. Such oscillations were absent prior to the onset of hearing, intrinsically generated by hyperpolarization-activated cyclic nucleotide-gated (HCN) and persistent Na+ conductances (NaP) interacting with passive membrane properties, and reflected the intrinsic resonance properties of fusiform cells. Cx36-containing gap junctions facilitated oscillation strength and promoted pairwise synchrony of oscillations between neighboring neurons. The strength of oscillations were strikingly sensitive to external Ca2+, disappearing at concentrations >1.7 mM, due in part to the shunting effect of small-conductance calcium-activated potassium (SK) channels. This effect explains their apparent absence in previous in vitro studies of cochlear nucleus which routinely employed high-Ca2+ extracellular solution. In contrast, oscillations were amplified in reduced Ca2+ solutions, due to relief of suppression by Ca2+ of Na+ channel gating. Our results thus reveal mechanisms for synchronous oscillatory activity in auditory brainstem, suggesting that slow oscillations, and by extension their perceptual effects, may originate at the earliest stages of sensory processing.


Subject(s)
Calcium , Cochlear Nucleus , Mice , Animals , Calcium/metabolism , Cochlear Nucleus/physiology , Neurons/physiology , Membrane Potentials/physiology , Afferent Pathways/physiology
4.
J Neurosci ; 44(30)2024 Jul 24.
Article in English | MEDLINE | ID: mdl-38918064

ABSTRACT

Linking sensory input and its consequences is a fundamental brain operation. During behavior, the neural activity of neocortical and limbic systems often reflects dynamic combinations of sensory and task-dependent variables, and these "mixed representations" are suggested to be important for perception, learning, and plasticity. However, the extent to which such integrative computations might occur outside of the forebrain is less clear. Here, we conduct cellular-resolution two-photon Ca2+ imaging in the superficial "shell" layers of the inferior colliculus (IC), as head-fixed mice of either sex perform a reward-based psychometric auditory task. We find that the activity of individual shell IC neurons jointly reflects auditory cues, mice's actions, and behavioral trial outcomes, such that trajectories of neural population activity diverge depending on mice's behavioral choice. Consequently, simple classifier models trained on shell IC neuron activity can predict trial-by-trial outcomes, even when training data are restricted to neural activity occurring prior to mice's instrumental actions. Thus, in behaving mice, auditory midbrain neurons transmit a population code that reflects a joint representation of sound, actions, and task-dependent variables.


Subject(s)
Auditory Perception , Inferior Colliculi , Animals , Mice , Male , Inferior Colliculi/physiology , Female , Auditory Perception/physiology , Acoustic Stimulation/methods , Mesencephalon/physiology , Auditory Pathways/physiology , Mice, Inbred C57BL , Neurons/physiology , Reward
5.
J Neurosci ; 44(7)2024 Feb 14.
Article in English | MEDLINE | ID: mdl-38123993

ABSTRACT

Layer 5 pyramidal neurons of sensory cortices project "corticofugal" axons to myriad sub-cortical targets, thereby broadcasting high-level signals important for perception and learning. Recent studies suggest dendritic Ca2+ spikes as key biophysical mechanisms supporting corticofugal neuron function: these long-lasting events drive burst firing, thereby initiating uniquely powerful signals to modulate sub-cortical representations and trigger learning-related plasticity. However, the behavioral relevance of corticofugal dendritic spikes is poorly understood. We shed light on this issue using 2-photon Ca2+ imaging of auditory corticofugal dendrites as mice of either sex engage in a GO/NO-GO sound-discrimination task. Unexpectedly, only a minority of dendritic spikes were triggered by behaviorally relevant sounds under our conditions. Task related dendritic activity instead mostly followed sound cue termination and co-occurred with mice's instrumental licking during the answer period of behavioral trials, irrespective of reward consumption. Temporally selective, optogenetic silencing of corticofugal neurons during the trial answer period impaired auditory discrimination learning. Thus, auditory corticofugal systems' contribution to learning and plasticity may be partially nonsensory in nature.


Subject(s)
Auditory Cortex , Inferior Colliculi , Mice , Animals , Inferior Colliculi/physiology , Auditory Cortex/physiology , Neurons/physiology , Auditory Perception/physiology , Pyramidal Cells , Auditory Pathways/physiology , Acoustic Stimulation
6.
Am J Hum Genet ; 109(3): 508-517, 2022 03 03.
Article in English | MEDLINE | ID: mdl-35172124

ABSTRACT

Non-obstructive azoospermia (NOA) is a severe and frequent cause of male infertility, often treated by testicular sperm extraction followed by intracytoplasmic sperm injection. The aim of this study is to improve the genetic diagnosis of NOA, by identifying new genes involved in human NOA and to better assess the chances of successful sperm extraction according to the individual's genotype. Exome sequencing was performed on 96 NOA-affected individuals negative for routine genetic tests. Bioinformatics analysis was limited to a panel of 151 genes selected as known causal or candidate genes for NOA. Only highly deleterious homozygous or hemizygous variants were retained as candidates. A likely causal defect was identified in 16 genes in a total of 22 individuals (23%). Six genes had not been described in man (DDX25, HENMT1, MCMDC2, MSH5, REC8, TDRKH) and 10 were previously reported (C14orf39, DMC1, FANCM, GCNA, HFM1, MCM8, MEIOB, PDHA2, TDRD9, TERB1). Seven individuals had defects in genes from piwi or DNA repair pathways, three in genes involved in post-meiotic maturation, and 12 in meiotic processes. Interestingly, all individuals with defects in meiotic genes had an unsuccessful sperm retrieval, indicating that genetic diagnosis prior to TESE could help identify individuals with low or null chances of successful sperm retrieval and thus avoid unsuccessful surgeries.


Subject(s)
Azoospermia , Azoospermia/diagnosis , Azoospermia/genetics , DNA Helicases/metabolism , DNA-Binding Proteins/genetics , Humans , Male , Sperm Retrieval , Testis/metabolism , Exome Sequencing
7.
J Neurosci ; 43(31): 5642-5655, 2023 08 02.
Article in English | MEDLINE | ID: mdl-37308295

ABSTRACT

The inferior colliculus (IC) is a midbrain hub critical for perceiving complex sounds, such as speech. In addition to processing ascending inputs from most auditory brainstem nuclei, the IC receives descending inputs from auditory cortex that control IC neuron feature selectivity, plasticity, and certain forms of perceptual learning. Although corticofugal synapses primarily release the excitatory transmitter glutamate, many physiology studies show that auditory cortical activity has a net inhibitory effect on IC neuron spiking. Perplexingly, anatomy studies imply that corticofugal axons primarily target glutamatergic IC neurons while only sparsely innervating IC GABA neurons. Corticofugal inhibition of the IC may thus occur largely independently of feedforward activation of local GABA neurons. We shed light on this paradox using in vitro electrophysiology in acute IC slices from fluorescent reporter mice of either sex. Using optogenetic stimulation of corticofugal axons, we find that excitation evoked with single light flashes is indeed stronger in presumptive glutamatergic neurons compared with GABAergic neurons. However, many IC GABA neurons fire tonically at rest, such that sparse and weak excitation suffices to significantly increase their spike rates. Furthermore, a subset of glutamatergic IC neurons fire spikes during repetitive corticofugal activity, leading to polysynaptic excitation in IC GABA neurons owing to a dense intracollicular connectivity. Consequently, recurrent excitation amplifies corticofugal activity, drives spikes in IC GABA neurons, and generates substantial local inhibition in the IC. Thus, descending signals engage intracollicular inhibitory circuits despite apparent constraints of monosynaptic connectivity between auditory cortex and IC GABA neurons.SIGNIFICANCE STATEMENT Descending "corticofugal" projections are ubiquitous across mammalian sensory systems, and enable the neocortex to control subcortical activity in a predictive or feedback manner. Although corticofugal neurons are glutamatergic, neocortical activity often inhibits subcortical neuron spiking. How does an excitatory pathway generate inhibition? Here we study the corticofugal pathway from auditory cortex to inferior colliculus (IC), a midbrain hub important for complex sound perception. Surprisingly, cortico-collicular transmission was stronger onto IC glutamatergic compared with GABAergic neurons. However, corticofugal activity triggered spikes in IC glutamate neurons with local axons, thereby generating strong polysynaptic excitation and feedforward spiking of GABAergic neurons. Our results thus reveal a novel mechanism that recruits local inhibition despite limited monosynaptic convergence onto inhibitory networks.


Subject(s)
Auditory Cortex , Inferior Colliculi , Mice , Animals , Inferior Colliculi/physiology , Auditory Cortex/physiology , Axons , GABAergic Neurons/metabolism , Glutamates , Auditory Pathways/physiology , Acoustic Stimulation , Mammals
8.
J Neurophysiol ; 131(5): 842-864, 2024 05 01.
Article in English | MEDLINE | ID: mdl-38505907

ABSTRACT

The inferior colliculus (IC) of the midbrain is important for complex sound processing, such as discriminating conspecific vocalizations and human speech. The IC's nonlemniscal, dorsal "shell" region is likely important for this process, as neurons in these layers project to higher-order thalamic nuclei that subsequently funnel acoustic signals to the amygdala and nonprimary auditory cortices, forebrain circuits important for vocalization coding in a variety of mammals, including humans. However, the extent to which shell IC neurons transmit acoustic features necessary to discern vocalizations is less clear, owing to the technical difficulty of recording from neurons in the IC's superficial layers via traditional approaches. Here, we use two-photon Ca2+ imaging in mice of either sex to test how shell IC neuron populations encode the rate and depth of amplitude modulation, important sound cues for speech perception. Most shell IC neurons were broadly tuned, with a low neurometric discrimination of amplitude modulation rate; only a subset was highly selective to specific modulation rates. Nevertheless, neural network classifier trained on fluorescence data from shell IC neuron populations accurately classified amplitude modulation rate, and decoding accuracy was only marginally reduced when highly tuned neurons were omitted from training data. Rather, classifier accuracy increased monotonically with the modulation depth of the training data, such that classifiers trained on full-depth modulated sounds had median decoding errors of ∼0.2 octaves. Thus, shell IC neurons may transmit time-varying signals via a population code, with perhaps limited reliance on the discriminative capacity of any individual neuron.NEW & NOTEWORTHY The IC's shell layers originate a "nonlemniscal" pathway important for perceiving vocalization sounds. However, prior studies suggest that individual shell IC neurons are broadly tuned and have high response thresholds, implying a limited reliability of efferent signals. Using Ca2+ imaging, we show that amplitude modulation is accurately represented in the population activity of shell IC neurons. Thus, downstream targets can read out sounds' temporal envelopes from distributed rate codes transmitted by populations of broadly tuned neurons.


Subject(s)
Auditory Perception , Inferior Colliculi , Neurons , Inferior Colliculi/physiology , Animals , Mice , Male , Female , Auditory Perception/physiology , Neurons/physiology , Mice, Inbred C57BL , Acoustic Stimulation , Neural Networks, Computer
9.
Am J Hum Genet ; 108(2): 309-323, 2021 02 04.
Article in English | MEDLINE | ID: mdl-33472045

ABSTRACT

Asthenoteratozoospermia characterized by multiple morphological abnormalities of the flagella (MMAF) has been identified as a sub-type of male infertility. Recent progress has identified several MMAF-associated genes with an autosomal recessive inheritance in human affected individuals, but the etiology in approximately 40% of affected individuals remains unknown. Here, we conducted whole-exome sequencing (WES) and identified hemizygous missense variants in the X-linked CFAP47 in three unrelated Chinese individuals with MMAF. These three CFAP47 variants were absent in human control population genome databases and were predicted to be deleterious by multiple bioinformatic tools. CFAP47 encodes a cilia- and flagella-associated protein that is highly expressed in testis. Immunoblotting and immunofluorescence assays revealed obviously reduced levels of CFAP47 in spermatozoa from all three men harboring deleterious missense variants of CFAP47. Furthermore, WES data from an additional cohort of severe asthenoteratozoospermic men originating from Australia permitted the identification of a hemizygous Xp21.1 deletion removing the entire CFAP47 gene. All men harboring hemizygous CFAP47 variants displayed typical MMAF phenotypes. We also generated a Cfap47-mutated mouse model, the adult males of which were sterile and presented with reduced sperm motility and abnormal flagellar morphology and movement. However, fertility could be rescued by the use of intra-cytoplasmic sperm injections (ICSIs). Altogether, our experimental observations in humans and mice demonstrate that hemizygous mutations in CFAP47 can induce X-linked MMAF and asthenoteratozoospermia, for which good ICSI prognosis is suggested. These findings will provide important guidance for genetic counseling and assisted reproduction treatments.


Subject(s)
Asthenozoospermia/genetics , Infertility, Male/genetics , Animals , Asthenozoospermia/pathology , Asthenozoospermia/physiopathology , Cohort Studies , Female , Gene Deletion , Genes, X-Linked , Hemizygote , Humans , Infertility, Male/metabolism , Infertility, Male/pathology , Infertility, Male/physiopathology , Male , Mice, Inbred C57BL , Mutation , Mutation, Missense , Pedigree , Phenotype , Sperm Injections, Intracytoplasmic , Sperm Motility , Sperm Tail/ultrastructure , Spermatozoa/pathology , Spermatozoa/physiology , Spermatozoa/ultrastructure , Exome Sequencing
10.
Development ; 148(23)2021 12 01.
Article in English | MEDLINE | ID: mdl-34792097

ABSTRACT

Defects in the structure or motility of cilia and flagella may lead to severe diseases such as primary ciliary dyskinesia (PCD), a multisystemic disorder with heterogeneous manifestations affecting primarily respiratory and reproductive functions. We report that CFAP61 is a conserved component of the calmodulin- and radial spoke-associated complex (CSC) of cilia. We find that a CFAP61 splice variant, c.143+5G>A, causes exon skipping/intron retention in human, inducing a multiple morphological abnormalities of the flagella (MMAF) phenotype. We generated Cfap61 knockout mice that recapitulate the infertility phenotype of the human CFAP61 mutation, but without other symptoms usually observed in PCD. We find that CFAP61 interacts with the CSC, radial spoke stalk and head. During early stages of Cfap61-/- spermatid development, the assembly of radial spoke components is impaired. As spermiogenesis progresses, the axoneme in Cfap61-/- cells becomes unstable and scatters, and the distribution of intraflagellar transport proteins is disrupted. This study reveals an organ-specific mechanism of axoneme stabilization that is related to male infertility.


Subject(s)
Infertility, Male , Membrane Proteins , Point Mutation , Sperm Tail/metabolism , Spermatids/metabolism , Spermatogenesis/genetics , Animals , Axoneme/genetics , Axoneme/metabolism , Humans , Infertility, Male/genetics , Infertility, Male/metabolism , Male , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Mice, Knockout , RNA Splicing
11.
Clin Genet ; 105(3): 317-322, 2024 03.
Article in English | MEDLINE | ID: mdl-37975235

ABSTRACT

Sperm flagella share an evolutionary conserved microtubule-based structure with motile cilia expressed at the surface of several cell types, such as the airways epithelial cells. As a result, male infertility can be observed as an isolated condition or a syndromic trait, illustrated by Primary Cilia Dyskinesia (PCD). We report two unrelated patients showing multiple morphological abnormalities of the sperm flagella (MMAF) and carrying distinct homozygous truncating variants in the PCD-associated gene CCDC65. We characterized one of the identified variants (c.1208del; p.Asn403Ilefs*9), which induces the near absence of CCDC65 protein in patient sperm. In Chlamydomonas, CCDC65 ortholog (DRC2, FAP250) is a component of the Nexin-Dynein Regulatory complex (N-DRC), which interconnects microtubule doublets and coordinates dynein arms activity. In sperm cells from the patient, we also show the loss of GAS8, another component of the N-DRC, supporting a structural/functional link between the two proteins. Our work indicates that, similarly to ciliary axoneme, CCDC65 is required for sperm flagellum structure. Importantly, our work provides first evidence that mutations in the PCD-associated gene CCDC65 also cause asthenozoospermia.


Subject(s)
Infertility, Male , Sperm Tail , Humans , Male , Sperm Tail/metabolism , Axoneme/genetics , Seeds/metabolism , Microtubule-Associated Proteins/genetics , Mutation/genetics , Dyneins/genetics , Infertility, Male/genetics , Glycoproteins/genetics
12.
Clin Genet ; 105(2): 220-225, 2024 02.
Article in English | MEDLINE | ID: mdl-37950557

ABSTRACT

Motile cilia and flagella are closely related organelles structured around a highly conserved axoneme whose formation and maintenance involve proteins from hundreds of genes. Defects in many of these genes have been described to induce primary ciliary dyskinesia (PCD) mainly characterized by chronic respiratory infections, situs inversus and/or infertility. In men, cilia/flagella-related infertility is usually caused by asthenozoospermia due to multiple morphological abnormalities of the sperm flagella (MMAF). Here, we investigated a cohort of 196 infertile men displaying a typical MMAF phenotype without any other PCD symptoms. Analysis of WES data identified a single case carrying a deleterious homozygous GAS8 variant altering a splice donor consensus site. This gene, also known as DRC4, encodes a subunit of the Nexin-Dynein Regulatory Complex (N-DRC), and has been already associated to male infertility and mild PCD. Confirming the deleterious effect of the candidate variant, GAS8 staining by immunofluorescence did not evidence any signal from the patient's spermatozoa whereas a strong signal was present along the whole flagella length in control cells. Concordant with its role in the N-DRC, transmission electron microscopy evidenced peripheral microtubule doublets misalignments. We confirm here the importance of GAS8 in the N-DRC and observed that its absence induces a typical MMAF phenotype not necessarily accompanied by other PCD symptoms.


Subject(s)
Axoneme , Infertility, Male , Male , Humans , Axoneme/genetics , Mutation , Semen , Sperm Tail , Infertility, Male/genetics , Spermatozoa , Flagella , Microtubule-Associated Proteins/genetics , Dyneins/genetics
13.
Clin Genet ; 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38956960

ABSTRACT

Non-obstructive azoospermia (NOA) resulting from primary spermatogenic failure represents one of the most severe forms of male infertility, largely because therapeutic options are very limited. Beyond their diagnostic value, genetic tests for NOA also hold prognostic potential. Specifically, genetic diagnosis enables the establishment of genotype-testicular phenotype correlations, which, in some cases, provide a negative predictive value for testicular sperm extraction (TESE), thereby preventing unnecessary surgical procedures. In this study, we employed whole-genome sequencing (WGS) to investigate two generations of an Iranian family with NOA and identified a homozygous splicing variant in TDRKH (NM_001083965.2: c.562-2A>T). TDRKH encodes a conserved mitochondrial membrane-anchored factor essential for piRNA biogenesis in germ cells. In Tdrkh knockout mice, de-repression of retrotransposons in germ cells leads to spermatogenic arrest and male infertility. Previously, our team reported TDRKH involvement in human NOA cases through the investigation of a North African cohort. This current study marks the second report of TDRKH's role in NOA and human male infertility, underscoring the significance of the piRNA pathway in spermatogenesis. Furthermore, across both studies, we demonstrated that men carrying TDRKH variants, similar to knockout mice, exhibit complete spermatogenic arrest, correlating with failed testicular sperm retrieval.

14.
Eur J Nutr ; 63(5): 1555-1564, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38703227

ABSTRACT

IMPORTANCE AND OBJECTIVE: Self-reported caffeine consumption has been widely used in research while it may be subject to bias. We sought to investigate the associations between self-reported caffeine consumption and plasma levels of caffeine and its two main metabolites (paraxanthine and theophylline) in the community. METHODS: Data from two population-based studies (SKIPOGH1 and 2 (N = 1246) and CoLaus|PsyCoLaus (N = 4461)) conducted in Switzerland were used. Self-reported caffeine consumption was assessed using questionnaires. Plasma levels of caffeine and its metabolites were quantified by ultra-high performance liquid chromatography coupled to a tandem quadrupole mass spectrometer. RESULTS: In both studies, mean log plasma levels of caffeine and its two metabolites were over 6.48 (plasma levels = 652 ng/ml) when no caffeine consumption was reported. Subsequently, nonlinear associations between log plasma levels and self-reported caffeine consumption were observed in SKIPOGH, with a change of the slope at 3-5 cups of espresso per day in SKIPOGH1 but not SKIPOGH2. In CoLaus|PsyCoLaus, increased daily consumption of caffeinated beverages was associated with increased log plasma levels with a change of the slope at 3 cups. In both studies, declared caffeine consumption higher than 3-5 cups per day was not associated with higher plasma levels of caffeine and its metabolites. CONCLUSION: Self-reports of no or low caffeine consumption and consumption of more than 3-5 cups of coffee should be interpreted with caution, with possible under- or over-estimation. Quantifying plasma levels of caffeine and its metabolites may contribute to a better estimation of caffeine intake.


Subject(s)
Caffeine , Self Report , Theophylline , Caffeine/blood , Caffeine/administration & dosage , Humans , Female , Male , Theophylline/blood , Middle Aged , Adult , Switzerland , Coffee , Surveys and Questionnaires , Aged , Chromatography, High Pressure Liquid/methods
15.
BMC Psychiatry ; 24(1): 217, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38509477

ABSTRACT

BACKGROUND: A suicide attempt (SA) is a clinically serious action. Researchers have argued that reducing long-term SA risk may be possible, provided that at-risk individuals are identified and receive adequate treatment. Algorithms may accurately identify at-risk individuals. However, the clinical utility of algorithmically estimated long-term SA risk has never been the predominant focus of any study. METHODS: The data of this report stem from CoLaus|PsyCoLaus, a prospective longitudinal study of general community adults from Lausanne, Switzerland. Participants (N = 4,097; Mage = 54 years, range: 36-86; 54% female) were assessed up to four times, starting in 2003, approximately every 4-5 years. Long-term individual SA risk was prospectively predicted, using logistic regression. This algorithm's clinical utility was assessed by net benefit (NB). Clinical utility expresses a tool's benefit after having taken this tool's potential harm into account. Net benefit is obtained, first, by weighing the false positives, e.g., 400 individuals, at the risk threshold, e.g., 1%, using its odds (odds of 1% yields 1/(100-1) = 1/99), then by subtracting the result (400*1/99 = 4.04) from the true positives, e.g., 5 individuals (5-4.04), and by dividing the result (0.96) by the sample size, e.g., 800 (0.96/800). All results are based on 100 internal cross-validations. The predictors used in this study were: lifetime SA, any lifetime mental disorder, sex, and age. RESULTS: SA at any of the three follow-up study assessments was reported by 1.2%. For a range of seven a priori selected threshold probabilities, ranging between 0.5% and 2%, logistic regression showed highest overall NB in 97.4% of all 700 internal cross-validations (100 for each selected threshold probability). CONCLUSION: Despite the strong class imbalance of the outcome (98.8% no, 1.2% yes) and only four predictors, clinical utility was observed. That is, using the logistic regression model for clinical decision making provided the most true positives, without an increase of false positives, compared to all competing decision strategies. Clinical utility is one among several important prerequisites of implementing an algorithm in routine practice, and may possibly guide a clinicians' treatment decision making to reduce long-term individual SA risk. The novel metric NB may become a standard performance measure, because the a priori invested clinical considerations enable clinicians to interpret the results directly.


Subject(s)
Suicide, Attempted , Adult , Humans , Female , Middle Aged , Male , Risk Factors , Longitudinal Studies , Prospective Studies , Follow-Up Studies
16.
Compr Psychiatry ; 129: 152442, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38070447

ABSTRACT

BACKGROUND: Lack of physical activity (PA) and high sedentary behavior (SB) may enhance mental health problems, including depression, and are associated with increased mortality. Aside from a large body of research on major depressive disorder (MDD) assessed as an entity and either PA or SB, few studies have examined associations among subtypes of MDD and both PA and SB simultaneously derived from wrist-worn accelerometers. Accordingly, our aim was to explore the associations among MDD subtypes (atypical, melancholic, combined atypical-melancholic and unspecified) and four actigraphy-derived behaviors combining the levels of PA and SB. METHODS: The sample stemmed from CoLaus|PsyCoLaus, a population-based cohort study, consisting of 2375 participants (55.1% women; mean age: 62.4 years) who wore an accelorometer for 14 days after a physical exam and subsequently completed a semi-structured psychiatric interview. Activity behaviors were defined according to the combination of the levels of moderate-to-vigorous intensity PA and SB. Associations of remitted MDD subtypes, current MDD and physical inactivity behaviors were assessed using multinomial logistic regression, adjusted for socio-demographic characteristics, a history of anxiety, alcohol and drug use disorders and cardiovascular risk factors. RESULTS: In the fully adjusted model, participants with the remitted combined atypical-melancholic subtype had a higher risk of being more physically inactive. CONCLUSIONS: Our findings suggest that low PA and high SB are not restricted to the duration of depressive episodes in people with atypical and melancholic episodes. The lack of PA and high SB in this group of depressive patients exposes them to an additional long-term cardiovascular risk and measures to increase PA may be particularly fruitful in this MDD subgroup.


Subject(s)
Depressive Disorder, Major , Humans , Female , Middle Aged , Male , Depressive Disorder, Major/diagnosis , Depressive Disorder, Major/epidemiology , Depressive Disorder, Major/psychology , Sedentary Behavior , Cohort Studies , Exercise , Depression
17.
Respiration ; 103(8): 503-512, 2024.
Article in English | MEDLINE | ID: mdl-38417406

ABSTRACT

INTRODUCTION: Mental health disorders figure among the many comorbidities of obstructive respiratory diseases. The multisystemic characteristics of chronic respiratory disease and its impact on quality of life could affect depressive and/or anxiety disorders. We aimed to evaluate the association of spirometric indices, ventilatory disorders, and self-reported respiratory diseases with psychiatric disorders considering potential confounders. METHODS: We analysed data from CoLaus|PsyCoLaus, a Swiss population-based cohort study, consisting of 2'774 participants (56% women; mean age: 62.3 (standard deviation = ±9.9) years) who performed spirometry and completed semi-structured psychiatric interviews. We defined ventilatory disorders using GLI-2012 references. Major depressive episode (MDE) and anxiety disorders were defined using the DSM-IV (Diagnostic and Statistical Manual). RESULTS: 630 subjects (22.7%) presented a recent MDE. Reversible obstructive ventilatory disorders were associated with recent MDE (OR = 1.94, 95% confidence interval (95% CI) 1.10-3.43) and recent anxiety disorders (2.21 [1.16-4.22]) only in unadjusted model. Self-reported chronic obstructive pulmonary (COPD) and asthma were associated with MDE with ORs of 2.49 (95% CI, 1.19-5.27) and 1.56 (95% CI, 1.04-2.35) after adjustment, respectively. Possible restrictive ventilatory impairment was positively associated with recent anxiety disorders (OR = 2.46, 1.10-5.51). Z-scores of FEV1, FVC, and maximal mid-expiratory flow were not associated with psychiatric disorders. There was no association between ventilatory disorders and MDE in adjusted models. CONCLUSIONS: In this cross-sectional population-based study, the association between respiratory disorders and depressive disorders was observed for self-reported COPD and asthma, but not with objective diagnoses based on spirometry. Lung volumes are not associated with psychiatric disorders. Further prospective studies will be necessary to understand the significance of the association.


Subject(s)
Anxiety Disorders , Humans , Female , Male , Middle Aged , Anxiety Disorders/epidemiology , Aged , Switzerland/epidemiology , Pulmonary Disease, Chronic Obstructive/epidemiology , Pulmonary Disease, Chronic Obstructive/psychology , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/physiopathology , Asthma/epidemiology , Asthma/complications , Asthma/psychology , Depressive Disorder, Major/epidemiology , Depressive Disorder, Major/complications , Spirometry , Cross-Sectional Studies , Cohort Studies , Comorbidity
18.
Article in English | MEDLINE | ID: mdl-39215821

ABSTRACT

PURPOSE: To prospectively assess (1) the associations of Effort-Reward Imbalance (ERI), its individual components, and over-commitment with (a) the onset of a Major Depressive Episode (MDE) during a 3.6-year follow-up in a population-based cohort in participants with no current Major Depressive Disorder (MDD) in the beginning of the follow-up (n = 959), (b) incidence of MDD in the subsample of participants exempt from lifetime MDD (n = 490), and (c) the onset of a new MDE (i.e. recurrence) in the subsample of participants with remitted but no current MDD (n = 485), and (2) potential effect modification of burnout on these associations. METHODS: DSM-IV Axis-I disorders were elicited using the semi-structured Diagnostic Instrument for Genetic Studies at each investigation. The ERI Questionnaire was used to measure ERI and overcommitment. Burnout was measured with the Maslach Burnout Inventory General Survey. Serially adjusted logistic regression models were used. The effect of burnout dimensions on these associations was assessed by testing interactions between the ERI and burnout dimensions. RESULTS: (1) ERI was prospectively associated with the onset of MDE, even after adjustment for burnout [OR (95CI) = 1.22 (1.003-1.49)]. (2) The association between ERI and MDD incidence became non-significant after adjusting for burnout. (3) ERI was not associated with recurrence of pre-existing MDD. (4) burnout did not interact with ERI. CONCLUSIONS: Our results support a longitudinal association between ERI and the risk of onset of MDE in the community. Burnout did not modify this effect, but it may partially account for the association between ERI and MDD incidence.

19.
J Acoust Soc Am ; 155(1): 656-672, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38270482

ABSTRACT

The stochastic dynamically orthogonal (DO) narrow-angle parabolic equations (NAPEs) are exemplified and their properties and capabilities are described using three new two-dimensional stochastic range-independent and range-dependent test cases with uncertain sound speed field, bathymetry, and source location. We validate results against ground-truth deterministic analytical solutions and direct Monte Carlo (MC) predictions of acoustic pressure and transmission loss fields. We verify the stochastic convergence and computational advantages of the DO-NAPEs and discuss the differences with normal mode approaches. Results show that a single DO-NAPE simulation can accurately predict stochastic range-dependent acoustic fields and their non-Gaussian probability distributions, with computational savings of several orders of magnitude when compared to direct MC methods. With their coupling properties and their adaptation in range to the dominant uncertainties, the DO-NAPEs are shown to predict accurate statistics, from mean and variance to multiple modes and full probability distributions, and to provide excellent reconstructed realizations, from amplitudes and phases to other specific properties of complex realization fields.

20.
J Acoust Soc Am ; 155(1): 640-655, 2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38270481

ABSTRACT

Robust informative acoustic predictions require precise knowledge of ocean physics, bathymetry, seabed, and acoustic parameters. However, in realistic applications, this information is uncertain due to sparse and heterogeneous measurements and complex ocean physics. Efficient techniques are thus needed to quantify these uncertainties and predict the stochastic acoustic wave fields. In this work, we derive and implement new stochastic differential equations that predict the acoustic pressure fields and their probability distributions. We start from the stochastic acoustic parabolic equation (PE) and employ the instantaneously-optimal Dynamically Orthogonal (DO) equations theory. We derive stochastic DO-PEs that dynamically reduce and march the dominant multi-dimensional uncertainties respecting the nonlinear governing equations and non-Gaussian statistics. We develop the dynamical reduced-order DO-PEs theory for the Narrow-Angle parabolic equation and implement numerical schemes for discretizing and integrating the stochastic acoustic fields.

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