Family Caregiver Comorbidities in Lewy Body Dementia Versus Alzheimer Disease and Associated Disorders.

BACKGROUND: Family caregivers of people living with dementia have high caregiver strain and poor health consequences. Limited research exists on Lewy body dementia (LBD) caregivers and their specific comorbidities. This study aimed to (1) identify the prevalence of self-reported comorbidities among LBD caregivers and (2) contextualize these findings with historical data on caregivers of persons living with Alzheimer disease and associated disorders (ADADs). METHODS: In a national, online survey, LBD family caregivers completed the Self-Administered Comorbidity Questionnaire and we compared these findings with extant literature on ADAD caregiver comorbidities. RESULTS: Among 217 LBD caregivers, 84.3% were female, 39.1% were 64 years old or younger, and 66.8% had >2 years of caregiving experience. Caregivers self-identified as current (83.9%) or former (16.1%) caregivers. The most frequent comorbidities were hypertension (38.2%), depression (35.0%), back pain (34.1%), and arthritis (27.7%). LBD caregivers, particularly younger caregivers, had a higher prevalence of depression compared with ADAD caregivers and older adult populations, and back pain prevalence nearly equivalent to spinal cord injury caregivers. CONCLUSIONS: Our study is the first to illustrate and contextualize specific comorbidities among LBD caregivers. Understanding the causality and impact of these conditions will be critical in designing effective interventions to improve the lives of families affected by LBD.

Central hemodynamic response to activation of the vestibular sympathetic reflex with head-down rotation in healthy young adults.

The purpose of this study was to assess the effect of vestibular sympathetic activation on estimated measures of central (aortic) hemodynamic load in young adults. Thirty-one participants (n = 14 females and 17 males) underwent cardiovascular measures in the prone position with the head in a neutral position and during 10 min of head-down rotation (HDR), as a means of activating the vestibular sympathetic reflex. Radial pressure waveforms were acquired via applanation tonometry and, with the use of a generalized transfer function, used to synthesize an aortic pressure waveform. Popliteal vascular conductance was derived from diameter and flow velocity measured via Doppler-ultrasound. Subjective orthostatic intolerance was assessed using a 10-item orthostatic hypotension questionnaire. There was a reduction in brachial systolic blood pressure (BP) during HDR (111 ± 10 vs. 109 ± 9 mmHg, P < 0.05), but there was no change in aortic systolic BP (100 ± 9 vs. 99 ± 8 mmHg, P > 0.05). Aortic augmentation index (-5 ± 11 vs. -12 ± 12%, P < 0.05) and reservoir pressure (28 ± 8 vs. 26 ± 8 mmHg, P < 0.05) were reduced with a concomitant reduction in popliteal conductance (5.6 ± 0.7 vs. 4.5 ± 0.7 mL/min·mmHg, P < 0.05). Change in aortic systolic BP was associated with subjective orthostatic intolerance score (r = -0.39, P < 0.05). Activation of the vestibular sympathetic reflex via HDR resulted in slight reductions in brachial BP concomitant with preservation of aortic BP. Despite peripheral vascular constriction during HDR, there was a reduction in pressure from wave reflections and reservoir pressure. Finally, there was an association between change in aortic systolic BP during HDR and orthostatic intolerance score, suggesting that individuals who cannot defend against drops in aortic BP during vestibular sympathetic reflex activation may be more likely to experience higher subjective symptomatology of orthostatic intolerance.NEW & NOTEWORTHY Despite peripheral vasoconstriction, activation of the vestibular-sympathetic reflex results in a reduction in cardiac workload. Reduction in cardiac workload is likely due to reductions in pressure from wave reflections and reservoir pressure.

Race, cortisol, and subclinical cardiovascular disease in 9- to 11-year-old children.

BACKGROUND: Non-Hispanic Black Americans have a greater risk for certain subtypes of cardiovascular disease (CVD; e.g., stroke and heart failure) relative to non-Hispanic White Americans. Moreover, Black relative to White adults consistently show elevated cortisol, a CVD risk. The impact of race, environmental stress, and cortisol on subclinical CVD has yet to be fully researched in children. METHOD: We assessed diurnal salivary cortisol slopes and hair cortisol in a sample of 9- to 11-year-old children (N = 271; 54% female) with roughly half self-identifying as either Black (57%) or White (43%). Two subclinical CVD indicators were assessed: carotid-femoral pulse wave velocity (cfPWV) and carotid intima-media thickness (cIMT). We assessed numerous environmental stress indicators. RESULTS: After adjusting for covariates, we found that Black children had significantly flatter diurnal cortisol slopes, higher hair cortisol, and thicker IMT than White children. Significant pathways were found: race → salivary cortisol slope → cfPWV (effect = -0.059, 95% CI [-0.116, -0.002]) and race → hair cortisol → cIMT (effect = -0.008, [-0.016, -0.002]). Black children also experienced significantly more environmental stress than White children; however, only income inequality served as a significant indirect pathway from race to salivary cortisol (effect = 0.029, [0.003, 0.060]). CONCLUSIONS: Relative to White children, Black children had significantly greater hair cortisol and flatter diurnal slopes which, in turn, were associated with greater subclinical CVD. As suggested by a significant indirect pathway, income inequality might partially explain the race-cortisol association. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Sub-lethal effects of permethrin exposure on a passerine: implications for managing ectoparasites in wild bird nests.

Permethrin is increasingly used for parasite control in bird nests, including nests of threatened passerines. We present the first formal evaluation of the effects of continued permethrin exposure on the reproductive success and liver function of a passerine, the zebra finch (Taeniopygia guttata), for two generations. We experimentally treated all nest material with a 1% permethrin solution or a water control and provided the material to breeding finches for nest building. The success of two consecutive clutches produced by the parental generation and one clutch produced by first-generation birds were tracked. Finches in the first generation were able to reproduce and fledge offspring after permethrin exposure, ruling out infertility. Permethrin treatment had no statistically significant effect on the number of eggs laid, number of days from clutch initiation to hatching, egg hatch rate, fledgling mass or nestling sex ratio in either generation. However, treating nest material with permethrin significantly increased the number of hatchlings in the first generation and decreased fledgling success in the second generation. Body mass for hatchlings exposed to permethrin was lower than for control hatchlings in both generations, but only statistically significant for the second generation. For both generations, an interaction between permethrin treatment and age significantly affected nestling growth. Permethrin treatment had no effect on liver function for any generation. Permethrin was detected inside 6 of 21 exposed, non-embryonated eggs (28.5% incidence; range: 693-4781 ng of permethrin per gram of dry egg mass). Overall, results from exposing adults, eggs and nestlings across generations to permethrin-treated nest material suggest negative effects on finch breeding success, but not on liver function. For threatened bird conservation, the judicious application of this insecticide to control parasites in nests can result in lower nestling mortality compared to when no treatment is applied. Thus, permethrin treatment benefits may outweigh its sub-lethal effects.

Temperature and life history: experimental heating leads female tree swallows to modulate egg temperature and incubation behaviour.

1. Life-history decisions are strongly affected by environmental conditions. In birds, incubation is energetically expensive and affected significantly by ambient temperature. We reduced energetic constraints for female tree swallows (Tachycineta bicolor) by experimentally heating nests during incubation by an average of 6.9 degrees C to test for changes in incubation behaviour. 2. Females in heated boxes (hereafter 'heated females') increased time spent incubating and maintained higher on-bout and off-bout egg temperatures. This indicates that female energetic constraints, not maximizing developmental conditions of offspring, determine incubation investment. Furthermore, this result suggests that embryonic developmental conditions in unmanipulated nests are suboptimal. 3. We found individual variation in how females responded to experimental heating. Early-laying (i.e. higher phenotypic quality) females with heated nests increased egg temperatures and maintained incubation constancy, while later-laying (lower quality) heated females increased incubation constancy. Changes in egg temperature were due to changes in female behaviour and not due directly to increases in internal nest-box temperatures. 4. Behaviour during the incubation period affected hatching asynchrony. Decreased variation in egg temperature led to lower levels of hatching asynchrony, which was also generally lower in heated nests. 5. Our study finds strong support for the prediction that intermittent incubators set their incubation investment at levels dictated by energetic constraints. Furthermore, females incubating in heated boxes allocated conserved energy primarily to increased egg temperature and increased incubation attentiveness. These results indicate that studies investigating the role of energetics in driving reproductive investment in intermittent incubators should consider egg temperature and individual variation more explicitly.

A framework to assess evolutionary responses to anthropogenic light and sound.

Human activities have caused a near-ubiquitous and evolutionarily-unprecedented increase in environmental sound levels and artificial night lighting. These stimuli reorganize communities by interfering with species-specific perception of time-cues, habitat features, and auditory and visual signals. Rapid evolutionary changes could occur in response to light and noise, given their magnitude, geographical extent, and degree to which they represent unprecedented environmental conditions. We present a framework for investigating anthropogenic light and noise as agents of selection, and as drivers of other evolutionary processes, to influence a range of behavioral and physiological traits such as phenological characters and sensory and signaling systems. In this context, opportunities abound for understanding contemporary and rapid evolution in response to human-caused environmental change.

Avian Incubation Patterns Reflect Temporal Changes in Developing Clutches.

Incubation conditions for eggs influence offspring quality and reproductive success. One way in which parents regulate brooding conditions is by balancing the thermal requirements of embryos with time spent away from the nest for self-maintenance. Age related changes in embryo thermal tolerance would thus be expected to shape parental incubation behavior. We use data from unmanipulated Black-capped Chickadee (Poecile atricapillus) nests to examine the temporal dynamics of incubation, testing the prediction that increased heat flux from eggs as embryos age influences female incubation behavior and/or physiology to minimize temperature fluctuations. We found that the rate of heat loss from eggs increased with embryo age. Females responded to increased egg cooling rates by altering incubation rhythms (more frequent, shorter on- and off- bouts), but not brood patch temperature. Consequently, as embryos aged, females were able to increase mean egg temperature and decrease variation in temperature. Our findings highlight the need to view full incubation as more than a static rhythm; rather, it is a temporally dynamic and finely adjustable parental behavior. Furthermore, from a methodological perspective, intra- and inter-specific comparisons of incubation rhythms and average egg temperatures should control for the stage of incubation.

An egg injection technique to evaluate the effect of polychlorinated biphenyls on the hatching success of the snapping turtle (Chelydra serpentina serpentina).

Embryos of oviparous organisms are exposed to contaminants by two pathways: contaminant uptake from the surrounding environment, and the transfer from female to offspring (maternal transfer). The initial source of contaminant exposure for most embryos is likely to be maternal transfer; therefore, maternal transfer studies are critical in determining the effects of contaminants on future populations. Injection of contaminants directly into eggs is one route of experimental contaminant exposure that permits controlled doses and potential reliable replication. This technique, however, has been used in the past with little success in reptiles. The objective of the present study was to evaluate egg injection as a means of mimicking maternal transfer of polychlorinated biphenyls (PCBs) to snapping turtle eggs. Eggs from several clutches were injected with a PCB solution and incubated at several temperatures and moisture levels to measure interactive effects of injection, environmental condition, and contaminant load on hatching success. The injection technique allowed for application of consistent and specific doses among replicates. Overall hatching success in this study was 61% and was as high as 71% within specific treatments. Hatching success was much higher in this study than in other studies using egg injections to mimic maternal transfer in chelonians and crocodilians.