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Some camouflaged animals hide colour signals and display them only transiently. These hidden colour signals are often conspicuous and are used as a secondary defence to warn or startle predators (deimatic displays) and/or to confuse them (flash displays). The hidden signals used in these displays frequently resemble typical aposematic signals, so it is possible that prey with hidden signals have evolved to employ colour patterns of a form that predators have previously learned to associate with unprofitability. Here, we tested this hypothesis by conducting two experiments that examined the effect of predator avoidance learning on the efficacy of deimatic and flash displays. We found that the survival benefits of both deimatic and flash displays were substantially higher against predators that had previously learned to associate the hidden colours with unprofitability than against naive predators. These findings help explain the phenological patterns we found in 1568 macro-lepidopteran species on three continents: species with hidden signals tend to occur later in the season than species without hidden signals.Some camouflaged animals hide colour signals and display them only transiently. These hidden colour signals are often conspicuous and are used as a secondary defence to warn or startle predators (deimatic displays) and/or to confuse them (flash displays). The hidden signals used in these displays frequently resemble typical aposematic signals, so it is possible that prey with hidden signals have evolved to employ colour patterns of a form that predators have previously learned to associate with unprofitability. Here, we tested this hypothesis by conducting two experiments that examined the effect of predator avoidance learning on the efficacy of deimatic and flash displays. We found that the survival benefits of both deimatic and flash displays were substantially higher against predators that had previously learned to associate the hidden colours with unprofitability than against naive predators. These findings help explain the phenological patterns we found in 1568 macro-lepidopteran species on three continents: species with hidden signals tend to occur later in the season than species without hidden signals.

Some camouflaged animals hide colour signals and display them only transiently. These hidden colour signals are often conspicuous and are used as a secondary defence to warn or startle predators (deimatic displays) and/or to confuse them (flash displays). The hidden signals used in these displays frequently resemble typical aposematic signals, so it is possible that prey with hidden signals have evolved to employ colour patterns of a form that predators have previously learned to associate with unprofitability. Here, we tested this hypothesis by conducting two experiments that examined the effect of predator avoidance learning on the efficacy of deimatic and flash displays. We found that the survival benefits of both deimatic and flash displays were substantially higher against predators that had previously learned to associate the hidden colours with unprofitability than against naive predators. These findings help explain the phenological patterns we found in 1568 macro-lepidopteran species on three continents: species with hidden signals tend to occur later in the season than species without hidden signals.

With the growing number of publicly listed property companies worldwide, investors are increasingly interested in assessing the risks of such real estate companies in the stock market. This study aims to investigate the risk of US equity real estate investment trusts (REITs) in the local market context. Using US equity REITs data from 1997 to 2020, this study examines the impact of local economic uncertainty (LEU) on risk of REITs. To measure LEU, we first exploit textual analysis to extract geographical information from REITs’ annual financial reports (10-K filings) and construct state-level regional exposure for each firm. We then obtain LEU by incorporating the regional exposure with local market uncertainty based on locally headquartered firms. In the empirical results, we find that REITs with higher LEU are strongly and positively associated with higher future risks. This positive relationship is robust to a variety of alternative risk and LEU measures. Moreover, the effects of LEU are stronger for geographically concentrated REITs and LEU is positively priced by investors.

Heat waves are occurring more frequently worldwide as global warming continues, and urban heat islands can threaten conventional life in cities. Measuring, analyzing, and simulating weather data at fine spatial and temporal scales are essential to prevent and reduce the damage caused by extreme heat waves. In urban environments, handling complex micrometeorological situations using current meteorological stations and global simulation models (e.g., weather research forecasting models) is challenging. In this study, the thermal environments of urban areas were measured using a mobile meteorological measurement platform. Both mobile and stationary datasets were incorporated into the meteorological modeling process to simulate the spatial and temporal distribution of temperature. Additionally, various mobile observation implementation scenarios for temperature modeling were examined. We compared simulation combinations with the temperature field generated from the total dataset to obtain a better sampling campaign and properly incorporate mobile data scenarios. When collecting mobile data, it is important to consider spatial features to improve the efficiency of sampling programs. This can substantially reduce the cost of mobile data collection, together with the sensor error bound.

This study introduces a novel portfolio allocation strategy, the flight-from-loss approach, designed to diversify tail risk in the REIT market. The strategy reallocates capital toward assets that have historically outperformed during periods of extreme REIT losses, aiming to reduce downside risk and improve portfolio efficiency. Using U.S. REIT data from 1993 to 2023, we demonstrate that our portfolio approach reduces tail risk significantly, while also enhancing Sharpe ratios compared to a REIT-only benchmark portfolio. These diversification benefits are particularly significant during market crises, such as the subprime mortgage crisis, when risk reduction exceeds 30%. Our analysis further reveals that the minimum-variance and tangency portfolio approaches consistently outperform the equal-weight method in both risk control and performance efficiency. To test the strategy’s generalizability, we applied it to the Fama-French 30 industry portfolios, where the results of some industries indicate even stronger risk reduction and Sharpe ratio gains than in the REIT market. These findings suggest that the flight-from-loss strategy offers a practical, cross-sector solution for managing concentrated portfolio risks.

Stressful circumstances are significant contributors to mental illnesses such as major depressive disorder. Anhedonia, defined as loss of the ability to enjoy pleasure in pleasurable situations, including rewarding activities or social contexts, is considered a key symptom of depression. Although stress-induced depression is associated with anhedonia in humans and animals, the underlying molecular mechanisms of anhedonic responses remain poorly understood. In this study, we demonstrated that synaptotagmin-4 (SYT4), which is involved in the release of neurotransmitters and neurotrophic factors, is implicated in chronic stress-induced anhedonia. Employing chronic unpredictable stress (CUS), we evaluated two subpopulations of mice, susceptible (SUS, anhedonic) and resilient (RES, nonanhedonic), based on sucrose preference, which was strongly correlated with social reward. The FosTRAP (targeted recombination in active populations) system and optogenetic approach revealed that neural activity in the medial prefrontal cortex (mPFC) was significantly associated with CUS-induced anhedonic behavioral phenotypes. By conducting weighted gene coexpression network analysis of RNA sequencing data from the mPFC of SUS and RES mice, we identified Syt4 as a hub gene in a gene network that was unique to anhedonia. We also confirmed that Syt4 overexpression in the mPFC was pro-susceptible, while Syt4 knockdown was pro-resilient; the pro-susceptible effects of SYT4 were mediated through a reduction in brain-derived neurotrophic factor (BDNF)-tropomyosin receptor kinase B (TrkB) signaling in the mPFC. These findings suggest that SYT4-BDNF interactions in the mPFC represent a crucial regulatory mechanism of anhedonic susceptibility to chronic stress. Chronic stress and depression: synaptotagmin-4 as a key player Depression is a complex mental health disorder that can significantly impact a person’s life. One symptom, anhedonia, is particularly difficult to treat. Researchers have been exploring why some people develop anhedonia and others don’t, especially under stress. The study, led by Jeongseop Kim and Sihwan Seol, aimed to discover the biological processes behind anhedonia. Using mice, the team exposed them to chronic unpredictable stress and observed their behaviors. They found that not all mice responded to stress with depressive-like behaviors, indicating individual differences in stress resilience. The researchers concluded that SYT4 and BDNF play crucial roles in the development of anhedonia and stress-induced depression. This study advances our understanding of the molecular basis of depression and could lead to new treatments targeting these mechanisms. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.

Depression, a prevalent neuropsychiatric disorder, involves the dysregulation of neurotransmitters such as dopamine (DA). The restoration of DA balance is a pivotal therapeutic target for this condition. Recent studies have indicated that both antidepressant medications and non-pharmacological treatments, such as transcutaneous auricular vagus nerve stimulation (taVNS), can promote recovery from depressive symptoms. Despite the promise of taVNS as a non-invasive depression therapy, its precise mechanism remains unclear. We hypothesized that taVNS exerts antidepressant effects by modulating the DAergic system. To investigate this, we conducted experiments demonstrating that taVNS in anesthetized mice reduced depressive-like behaviors. However, this effect was abolished when DA neurons in the ventral tegmental area (VTA DA ) were inhibited. Additionally, taVNS in anesthetized mice enhanced VTA DA activity, providing further evidence to support its antidepressant effects. Overall, our findings suggest that taVNS alleviates depression by augmenting VTA DA activity, thereby contributing to a more comprehensive understanding of its therapeutic mechanisms.

Beyond its role in parturition and lactation, oxytocin influences higher brain processes that control social behavior of mammals, and perturbed oxytocin signaling has been linked to the pathogenesis of several psychiatric disorders. However, it is still largely unknown how oxytocin exactly regulates neuronal function. We show that early, transient oxytocin exposure in vitro inhibits the development of hippocampal glutamatergic neurons, leading to reduced dendrite complexity, synapse density, and excitatory transmission, while sparing GABAergic neurons. Conversely, genetic elimination of oxytocin receptors increases the expression of protein components of excitatory synapses and excitatory synaptic transmission in vitro. In vivo, oxytocin-receptor-deficient hippocampal pyramidal neurons develop more complex dendrites, which leads to increased spine number and reduced γ-oscillations. These results indicate that oxytocin controls the development of hippocampal excitatory neurons and contributes to the maintenance of a physiological excitation/inhibition balance, whose disruption can cause neurobehavioral disturbances.

PurposeWe investigated the change in skin temperature of treated areas during intense pulsed light (IPL) treatment in patients who have meibomian gland dysfunction (MGD) to determine whether there is superficial telangiectatic blood vessel ablation.MethodsThe medical records of 90 patients (90 eyes) with MGD who underwent IPL treatment were reviewed. The patients had undergone IPL treatment four times every 4 weeks. Ocular Surface Disease Index (OSDI) scores, dry eye (DE), and MGD parameters were obtained before the first and after the fourth IPL treatments. The skin temperatures of the upper and lower lids were measured before every IPL treatment.ResultsThe skin temperatures of the lower lids were 31.89 ± 0.72°C at the first IPL (IPL#1), 30.89 ± 0.63°C at the second IPL (IPL#2), 30.14 ± 0.95°C at the third IPL (IPL#3), and 29.74 ± 0.87°C at the fourth IPL (IPL#4) treatments. The skin temperatures of upper lids were 32.01 ± 0.69°C at IPL#1, 31.13 ± 0.75°C at IPL#2, 30.34 ± 1.07°C at IPL#3, and 29.91 ± 0.76°C at IPL#4. The skin temperature of the upper and lower lids significantly decreased with every IPL treatment. Schirmer 1 test (ST) result was 12.97 ± 10.22 mm before IPL#1 and 14.45 ± 9.99 mm after IPL#4. Tear break-up time (TBUT) was 3.15 ± 1.38 s before IPL#1 and 5.53 ± 2.34 s after IPL#4. Corneal staining scores (CFS) was 1.61 ± 3.09 before IPL#1 and 0.50 ± 0.78 after IPL#4. Lipid layer thickness (LLT) was 71.88 ± 26.34 nm before IPL#1 and 68.38 ± 24.16 nm after IPL#4. Lid margin abnormality score (LAS) was 1.96 ± 0.62 before IPL#1 and 0.86 ± 0.67 after IPL#4. Meibum expressibility (ME) was 1.67 ± 0.87 before IPL#1 and 1.03 ± 1.67 after IPL#4. Meibum quality (MQ) was 18.18 ± 6.34 before IPL#1 and 10.16 ± 5.48 after IPL#4. OSDI was 35.38 ± 19.97 before IPL#1 and 15.48 ± 34.32 after IPL#4. OSDI scores, DE, and MGD parameters significantly improved after the fourth IPL treatment but not ST and LLT.ConclusionOur study showed that the occurrence of superficial telangiectatic vessels were indirectly reduced by the decrease in skin temperature accompanying IPL treatments in patients with MGD.

Astrocytes and metabotropic glutamate receptor 5 (mGluR5) have emerged as pivotal regulators of synaptic homeostasis and neural communication within the central nervous system (CNS). Although mGluR5 has long been considered neuron‐specific, its functional expression in astrocytes is now recognized as essential for calcium (Ca 2+ ) signaling, gliotransmission, and the modulation of synaptic plasticity. Dysregulation of astrocytic mGluR5 is increasingly implicated in the pathophysiology of neurodegenerative and psychiatric disorders including Alzheimer’s disease (AD), Parkinson’s disease (PD), depression, anxiety, and schizophrenia (SCZ) by promoting neuroinflammation, excitotoxicity, and synaptic dysfunction. In this review, we explore the emerging role of astrocytic mGluR5 in mediating astrocyte‐neuron communication and its maladaptive regulation in disease contexts. We also assess the therapeutic potential of targeting astrocytic mGluR5, highlighting advances in pharmacological modulators, gene therapy, and RNA‐based strategies aimed at restoring homeostatic function. Despite recent progress, critical knowledge gaps remain, particularly regarding the regional specificity of astrocytic mGluR5 effects, its crosstalk with other signaling pathways, and its contribution to chronic neuroinflammation. Addressing these challenges may unlock innovative astrocyte‐targeted therapies to restore synaptic integrity and protect against neurodegeneration in CNS disorders.