Annals of the New York Academy of Sciences最新文献

The dwarf lemurs (Cheirogaleus spp.) of Madagascar are the only obligate hibernators among primates. Despite century-old field accounts of seasonal lethargy, and more recent evidence of hibernation in the western fat-tailed dwarf lemur (Cheirogaleus medius), inducing hibernation in captivity remained elusive for decades. This included the Duke Lemur Center (DLC), which maintains fat-tailed dwarf lemurs and has produced sporadic research on reproduction and metabolism. With cumulative knowledge from the field, a newly robust colony, and better infrastructure, we recently induced hibernation in DLC dwarf lemurs. We describe two follow-up experiments in subsequent years. First, we show that dwarf lemurs under stable cold conditions (13°C) with available food continued to eat daily, expressed shallower and shorter torpor bouts, and had a modified gut microbiome compared to peers without food. Second, we demonstrate that dwarf lemurs under fluctuating temperatures (12–30°C) can passively rewarm daily, which was associated with altered patterns of fat depletion and reduced oxidative stress. Despite the limitations of working with endangered primates, we highlight the promise of studying hibernation in captive dwarf lemurs. Follow-up studies on genomics and epigenetics, metabolism, and endocrinology could have relevance across multidisciplinary fields, from biomedicine to evolutionary biology, and conservation.

Adolescents in low- and middle-income countries (LMICs) are a vulnerable population given increased nutritional needs as puberty approaches. School-based nutrition programs exist in some settings, but the comprehensive provision of nutrition services requires knowledge of the mechanisms to reach out-of-school adolescents. A comprehensive scoping review was performed using formal and informal search strategies to landscape all potential delivery platforms with nutrition services to reach adolescents. Peer-reviewed studies, institutional strategies, program evaluations, and programmatic reports in LMICs were reviewed, including gray literature. A total of 87 out of 270 identified publications and reports describing nutrition programs for adolescents were identified. Although nutrition programs targeted at adolescents were sparse, various innovative and inclusive delivery platforms were included, such as school feeding programs, school-based anemia control, and nutrition-friendly school initiatives; health facility–based, youth-friendly health and nutrition services; social safety nets targeted at adolescents; community-based approaches targeting youth development and peer education within youth centers and faith-based settings; and technology-based platforms, including digital health services and mass media communication sensitization and mobilization efforts. Existing delivery mechanisms and platforms in health and other sectors that target adolescents offer great potential to extend nutrition interventions to this vulnerable yet hard-to-reach population.

The neural network mediating successful response inhibition mainly includes right hemisphere activation of the pre-supplementary motor area, inferior frontal gyrus (IFG), subthalamic nucleus (STN), and caudate nucleus. However, the causal role of these regions in the inhibitory network is undefined. Five patients with Parkinson's disease were assessed prior to and after therapeutic thermal ablation of the right STN in two separate functional magnetic resonance imaging (fMRI) sessions while performing a stop-signal task. Initiation times were faster but motor inhibition with the left hand (contralateral to the lesion) was significantly impaired as evident in prolonged stop-signal reaction times. Reduced inhibition after right subthalamotomy was associated (during successful inhibition) with the recruitment of basal ganglia regions outside the established inhibitory network. They included the putamen and caudate together with the anterior cingulate cortex and IFG of the left hemisphere. Subsequent network connectivity analysis (with the seed over the nonlesioned left STN) revealed a new inhibitory network after right subthalamotomies. Our results highlight the causal role of the right STN in the neural network for motor inhibition and the possible basal ganglia mechanisms for compensation upon losing a key node of the inhibition network.

Elephants are known for strongly lateralized trunk behaviors, but the mechanisms driving elephant lateralization are poorly understood. Here, we investigate features of elephant mouth organization that presumably promote lateralization. We find the lower jaw of elephants is of narrow width, but is rostrally strongly elongated even beyond the jaw bone. Elephant lip vibrissae become progressively longer rostrally. Thus, elephants have two lateral dense, short microvibrissae arrays and central, less dense long macrovibrissae. This is an inversion of the ancestral mammalian facial vibrissae pattern, where central, dense short microvibrissae are flanked by two lateral macrovibrissae arrays. Elephant microvibrissae have smaller follicles than macrovibrissae. Similar to trunk-tip vibrissae, elephant lip microvibrissae show laterally asymmetric abrasion. Observations on Asian zoo elephants indicate lateralized abrasion results from lateralized feeding. It appears that the ancestral mammalian mouth (upper and lower lips, incisors, frontal microvibrissae) is shaped by oral food apprehension. The elephant mouth organization radically changed, however, because trunk-mediated feeding replaced oral apprehension. Such elephant mouth changes include the upper lip–nose fusion to the trunk, the super-flexible elongated lower jaw, the loss of incisors, and lateral rather than frontal microvibrissae. Elephants’ specialization for lateral food insertion is reflected by the reduction in the centering effects of oral food apprehension and lip vibrissae patterns.

Scientific progress within the last few decades has revealed the functional morphology of an insect's sticky footpads—a compliant pad that secretes thin liquid films. However, the physico-chemical mechanisms underlying their adhesion remain elusive. Here, we explore these underlying mechanisms by simultaneously measuring adhesive force and contact geometry of the adhesive footpads of live, tethered Indian stick insects, Carausius morosus, spanning more than two orders of magnitude in body mass. We find that the adhesive force we measure is similar to the previous measurements that use a centrifuge. Our measurements afford us the opportunity to directly probe the adhesive stress in vivo and use existing theory on capillary adhesion to predict the surface tension of the secreted liquid and compare it to previous assumptions. From our predictions, we find that the surface tension required to generate the adhesive stresses we observed ranges between 0.68 and 12 mN $�m^{�-�1�}$. The low surface tension of the liquid would enhance the wetting of the stick insect's footpads and promote their ability to conform to various substrates. Our insights may inform the biomimetic design of capillary-based, reversible adhesives and motivate future studies on the physico-chemical properties of the secreted liquid.

Formants, or resonance frequencies of the upper vocal tract, are an essential part of acoustic communication. Articulatory gestures—such as jaw, tongue, lip, and soft palate movements—shape formant structure in human vocalizations, but little is known about how nonhuman mammals use those gestures to modify formant frequencies. Here, we report a case study with an adult male harbor seal trained to produce an arbitrary vocalization composed of multiple repetitions of the sound wa. We analyzed jaw movements frame-by-frame and matched them to the tracked formant modulation in the corresponding vocalizations. We found that the jaw opening angle was strongly correlated with the first (F1) and, to a lesser degree, with the second formant (F2). F2 variation was better explained by the jaw angle opening when the seal was lying on his back rather than on the belly, which might derive from soft tissue displacement due to gravity. These results show that harbor seals share some common articulatory traits with humans, where the F1 depends more on the jaw position than F2. We propose further in vivo investigations of seals to further test the role of the tongue on formant modulation in mammalian sound production.

This study analyzes the relationship between drought processes and crop yields in Moldova, together with the effects of possible future climate change on crops. The severity of drought is analyzed over time in Moldova using the Standard Precipitation Index, the Standardized Precipitation Evapotranspiration Index, and their relationship with crop yields. In addition, rainfall variability and its relationship with crop yields are examined using spectral analysis and squared wavelet coherence. Observed station data (1950–2020 and 1850–2020), ERA5 reanalysis data (1950–2020), and climate model simulations (period 1970–2100) are used. Crop yield data (maize, sunflower, grape), data from experimental plots (wheat), and the Enhanced Vegetation Index from Moderate Resolution Imaging Spectroradiometer satellites were also used. Results show that although the severity of meteorological droughts has decreased in the last 170 years, the impact of precipitation deficits on different crop yields has increased, concurrent with a sharp increase in temperature, which negatively affected crop yields. Annual crops are now more vulnerable to natural rainfall variability and, in years characterized by rainfall deficits, the possibility of reductions in crop yield increases due to sharp increases in temperature. Projections reveal a pessimistic outlook in the absence of adaptation, highlighting the urgency of developing new agricultural management strategies.

Diabetes mellitus is currently approaching epidemic proportions and disproportionately affects patients in the hospital setting. In the United States, individuals living with diabetes represent over 17 million emergency department visits and 8 million admissions annually. The management of these patients in the hospital setting is complex and differs considerably from the outpatient setting. All patients with hyperglycemia should be screened for diabetes, as in-hospital hyperglycemia portends a greater risk for morbidity, mortality, admission to an intensive care unit, and increased hospital length of stay. However, the definition of hyperglycemia, glycemic targets, and strategies to manage hyperglycemia in the inpatient setting can vary greatly depending on the population considered. Moreover, the presenting illness, changing nutritional status, and concurrent hospital medications often necessitate thoughtful consideration to adjustments of home diabetes regimens and/or the initiation of new insulin doses. This review article will examine core concepts and emerging new literature surrounding inpatient diabetes management, including glycemic targets, insulin dosing strategies, noninsulin medications, new diabetes technologies, inpatient diabetes management teams, and discharge planning strategies, to optimize patient safety and satisfaction, clinical outcomes, and even hospital financial health.

Androgens, formerly known as anabolic-androgenic steroids, mimic the effects of testosterone and are being increasingly abused for nonmedical purposes such as body and performance enhancement. Androgen abuse is associated with increased mortality, and multisystem adverse effects have been reported, including cardiovascular toxicity, infertility, hypogonadism, hepatotoxicity, and mental health disorders. Men may present with the negative health consequences of androgen abuse even despite cessation for a number of years. There is frequently a reluctance to disclose androgen abuse, and substances are often sourced from the black market, which is not regulated and where the products sold may be counterfeit. All men should be encouraged to stop androgen abuse. Managing associated adverse effects will be organ-specific and is complex due to physical and neuropsychiatric symptoms, substance dependence, and high rates of relapse. Given the broad reach and prolonged adverse effects of androgen abuse, clinicians across medical specialties should have an awareness of androgen abuse, its increasing prevalence, and the harms it poses to men and their families. This narrative review aims to summarize the adverse effects and risks associated with androgen abuse.

In epidemiological studies, lowered serum testosterone concentrations are common in men with obesity, prediabetes, and established type 2 diabetes (T2D). In men with prediabetes, lowered serum testosterone also predicts a future risk of T2D in men. Administration of testosterone consistently reduces fat mass and increases skeletal muscle mass—body compositional changes expected to be metabolically favorable. In men with established T2D, the effects of testosterone treatment on glycemic measures are inconsistent. Irrespective of baseline serum testosterone concentration in men with prediabetes or newly diagnosed early-onset T2D, testosterone treatment prescribed in conjunction with a lifestyle program has been reported to reduce the risk of T2D by 40% after 2 years, suggesting that either a lifestyle program is required to facilitate the glycemic benefit of testosterone treatment and/or that testosterone treatment has more favorable effects on glycemia in men early in the evolution or onset of the disease. The durability of the benefit and longer-term safety of testosterone treatment have not been established. Therefore, more studies are required before testosterone treatment can be recommended for the prevention and/or treatment of men with or at elevated risk of T2D who do not have hypogonadism due to an established disease of the hypothalamic-pituitary-testicular axis.