Background Attention-deficit/hyperactivity disorder (ADHD) has been linked to obesity and type 2 diabetes, suggesting heightened cardiovascular risk. Whether adults with ADHD also show increased rates of metabolic syndrome (MetS), a cluster of central obesity, dyslipidemia, impaired glucose regulation, and hypertension, remains unclear. Methods We examined a young to middle-aged adult cohort of 83 patients and 82 healthy controls (HC). The primary objective was to test whether MetS (Joint Interim Statement criteria) was more prevalent in ADHD than in HC. To explore potential pathways linking ADHD with cardiovascular risk, we additionally assessed anthropometric indices, 24-h blood pressure (BP), heart rate (HR), and inflammatory markers (interleukin-6, C-reactive protein). Finally, we fitted a serial mediation model examining whether hyperactivity/impulsivity (HI), eating behavior, and body mass index (BMI) mediated the association between ADHD and BP. Results A higher proportion of ADHD patients fulfilled MetS criteria (OR 2.29). Adults with ADHD showed higher waist circumference, BMI, and overweight/obesity rates but did not differ in glucose and blood lipid levels. Non-stimulant medication and psychiatric comorbidity were more common among patients with MetS. Inflammatory markers were unrelated to ADHD. However, ADHD patients demonstrated slightly higher mean 24-h HR and nighttime systolic BP. The association between ADHD and nighttime systolic BP was mediated by obesity as a MetS constituent, and by HI and disordered eating as behavioral risk factors. Conclusion Young to middle-aged adults with ADHD displayed increased MetS prevalence and subtle elevations in nighttime BP and HR, suggesting an early cardiovascular risk trajectory. Behavioral factors, particularly overeating and weight gain, and psychiatric comorbidity appear to contribute to this risk. These findings support early cardiovascular screening and weight-management interventions in adults with ADHD.
The Higgs mode, originally proposed in the context of superconductivity, corresponds to oscillations of the amplitude of the superconducting order parameter. Recent terahertz-domain optical studies have found signatures consistent with the Higgs mode, but its unambiguous detection is still challenging. We predict that the existence of the Higgs mode can be unambiguously revealed by standard measurements of the transport characteristics in microwave-irradiated asymmetric and transparent Josephson junctions. One signature of the Higgs mode in a Josephson junction is the microwave-induced enhancement of the second harmonic of the equilibrium currentphase relation (at zero dc bias voltage), whose sign differs from its expected value in the absence of the Higgs mode. As the radiation frequency is varied, this enhancement exhibits resonant behavior when the microwave frequency is tuned across the Higgs mass. The second signature that we propose is the enhancement of the second harmonic of the ac Josephson current at finite dc voltage bias, which can be probed in a customary analysis of the Shapiro steps in a microwave-irradiated junction.
One of the main challenges of social parasitism is deceiving the host’s recognition system and thereby exploiting redirected altruistic behavior. Various chemical strategies have evolved to achieve this goal. The most widespread, used also by the obligate slave-making ants, is camouflage or mimicry of the colony odour encoded in cuticular hydrocarbon (CHC) composition. However, recent studies have shown that facultative slave-makers employ a different strategy: they manipulate the slaves’ recognition labels to make them resemble the parasite’s CHC profile. We examined the limitations of this strategy by focusing on incipient F. sanguinea colonies, where slaves are the majority. Our study revealed that callow F. sanguinea ants initially suppress their species-specific odour profile, which develops gradually over time, accompanied by an increase of the CHC amount per surface area in slave-maker workers. This allows the slaves to familiarise themselves with the parasite’s CHCs. We found that callow ants produce lower amounts of CHCs, and the relative abundance of certain compounds differs from that in older ants. Additionally, preimaginal stages of F. sanguinea ants acquire CHCs from the slaves, which are later incorporated into the recognition labels of the imagines. These findings support the proposition that the parasite’s manipulation strategy is limited by the slaves’ learning capacity, which is necessary to maintain colony cohesion. They also shed light on the selective pressures that might have led to the evolution of chemical mimicry in mature obligate slave-maker colonies. Social insects are characterized by colony-specific odours used for colony member recognition and ensuring proper targeting of altruistic behaviour. This barrier is challenged by social parasites that attempt to establish themselves in host colonies. Slave-making ants are unique in that they bring the host ants (so-called slaves) to their own nests. Like other social parasites, they use chemical mimicry by having a recognition odour similar to that of the host. However, the function of this adaptation is not clear, given that slave-makers live separately from host colonies. Our study demonstrates that in a facultative slave-making species, chemical mimicry is employed only in the initial phase of colony development when slaves constitute the majority of the slave-maker colony. This finding emphasizes the role of the slave proportion in the evolution of chemical strategies in slave-making ants.
During the evolution of insects, two principal types of attachment systems, hairy and smooth, evolved that enable them to attach to and move across diverse surfaces. Both rely on attachment supported by a thin film of fluid that enhances functionality. In some insects, multiple pad types occur on the same leg, each fulfilling complementary roles during attachment. Although their structural and mechanical differences are well understood, the secretion’s chemical composition and its functional implications remain largely unexplored. Stick and leaf insects (Phasmatodea) provide an ideal model to investigate these aspects, as they possess two morphologically and functionally distinct smooth attachment pads on the same tarsus: the pretarsal arolium, responsible for adhesion, and the tarsal euplantulae, specialised for friction. Using polydimethylsiloxane-coated solid-phase microextraction fibres and gas chromatography–mass spectrometry, we analysed the hydrocarbon profiles of both pad types and the body surface of Medauroidea extradentata. These data were compared with published profiles from other insect taxa possessing either hairy or smooth attachment systems to place our findings in a broader phylogenetic and functional context. Our analyses revealed distinct hydrocarbon compositions consistent with the specific mechanical roles of each structure. The arolium secretion was enriched with long-chain, methyl-branched hydrocarbons, likely enhancing fluidity and capillary forces, whereas the euplantulae secretion contained shorter, less methyl-branched hydrocarbons, suggesting higher viscosity, improving frictional contact. The body surface contained only n-alkanes, likely forming a wax-like protective layer. Comparisons across taxa revealed significant differences between smooth and hairy systems, reflecting both functional and phylogenetic influences on fluid chemistry.
Extracellular deposition of amyloid-β (Aβ) peptides in the form of plaques is the most prominent pathological hallmark of Alzheimer’s disease (AD). The postulated central pathophysiological role of fibrillary Aβ plaques has, however, been questioned, and small, soluble, pre-fibrillar Aβ aggregates (oligomers) have been implicated as the crucial neurotoxic species in AD etiology. While the relationship between insoluble amyloid plaques and soluble Aβ oligomers remains unclear, it has been hypothesized that plaques may serve as reservoirs, sequestering toxic Aβ oligomers in the initial stages of the disease. Next to the canonical “full-length” Aβ1-40 and Aβ1-42 peptides, a variety of N-terminally truncated Aβ variants are present in AD brain tissue, with Aβ4-42 peptides showing high abundance. The detrimental effects of these N-terminally truncated peptides have been previously studied using the Tg4-42hom mouse line, which displays neuron loss and cognitive deficits and accumulates Aβ4-42 peptides in the CA1 region of the hippocampus albeit without amyloid plaque formation. This study aimed to investigate the relationship between soluble Aβ4-42 peptides and insoluble extracellular Aβ deposits by crossing the Tg4-42hom line with the plaque-bearing 5XFAD mouse model. We found that extracellular amyloid deposits in the hippocampus did not aggravate spatial memory deficits in Tg4-42hom mice but rescued recognition memory deficits. Moreover, while proximal CA1 pyramidal neuron loss in the hippocampus of Tg4-42hom mice was not affected by crossing with the 5XFAD line, a reduced loss of distal pyramidal neurons was observed in the filial line. Biochemically, 5XFAD/Tg4-42hom mice showed a trend towards increased levels of insoluble Aβ4-x peptides in the hippocampus. Taken together, these findings support the importance of soluble Aβ oligomers in the pathogenesis of AD and provide evidence for the hypothesis that amyloid plaques provide buffering capacity.
