Mosquito Host-Seeking Diel Rhythm and Chemosensory Gene Expression is Affected by Age and Plasmodium Stages

Malaria parasites can affect vector-related behaviours, increasing transmission success. Using Anopheles gambiae and Plasmodium falciparum, we consider the effect of interaction between infection stage and vector age on diel locomotion in response to human odour and the expression of antennal chemosensory genes. We demonstrate age-dependent behavioural diel compartmentalisation by uninfected females. Infection disrupts overall and diel activity patterns compared with age-matched controls. Mosquitoes carrying transmissible sporozoites are more active, shifting activity periods to coincide with human host availability, in response to human odour. Older, uninfected females reduce activity during their peak host-seeking period in response to human odour. Age- and infection stage-specific changes in odour-mediated locomotion coincide with altered transcript abundance of select chemosensory genes providing a possible molecular mechanism regulating the behaviour. Our results support the hypothesis that vector-related behaviours of female mosquitoes are altered by infection stage and further modulated by the age of the vector, and have important implications for malaria transmission and disease dynamics.

The Wonderful DMARD with Multiple Toxicities

Methotrexate is a type of disease-modifying anti-rheumatic drug (DMARD). It is used to reduce activity of the immune system for people who have certain conditions. Methotrexate is a chemotherapy agent and immune system suppressant. Its use may be limited by concerns regarding its adverse reactions. The occurrence of adverse drug reactions in some cases leads to the therapy discontinuation. Although adverse drug reactions (ADR) of methotrexate generally do not pose a serious threat to the health of patients and a reduction in the dose of methotrexate leads to their elimination, in some cases severe toxicities of the drug occur unpredictably. These facts explain the need for close monitoring of the patient’s condition and the identification of potential risk factors for drug toxicity on the part of different organs and functional systems. The purpose of this review is to detail about safety and tolerability of methotrexate.

Warming in the land of the midnight sun: breeding birds may suffer greater heat stress at high- vs low-Arctic sites

Rising global temperatures are expected to increase reproductive costs for wildlife as greater thermoregulatory demands interfere with essential breeding activities such as parental care. However, predicting the temperature threshold where reproductive performance is negatively impacted remains a significant hurdle. Using a novel thermoregulatory polygon approach, we predicted the threshold temperature at which an Arctic songbird-the snow bunting (Plectrophenax nivalis)-would need to reduce activity and perform below the 4-times basal metabolic rate (BMR) required to sustain nestling provisioning to avoid overheating. We then compared this threshold to operative temperatures recorded at high (82°N) and low (64°N) Arctic sites to estimate how heat constraints translate into site-specific impacts on sustained activity level. We predict buntings would become behaviourally constrained at operative temperatures above 11.7°C, whereupon they must reduce provisioning rates to maintain thermal balance. Low Arctic sites had larger fluctuations in solar radiation, producing consistent daily periods when operative temperatures exceeded 11.7°C. However, high-latitude birds faced entire, consecutive days where parents would not be able to sustain required provisioning rates. These data indicate that Arctic warming is likely already disrupting the breeding performance of cold-specialist birds, but also suggests counterintuitive and severe negative impacts of warming at high-latitude breeding locations.

Potential Roles of Sestrin2 in Alzheimer’s Disease: Antioxidation, Autophagy Promotion, and Beyond

Alzheimer's disease (AD) is the most common age-related neurodegenerative disease. It presents with progressive memory loss, worsens cognitive functions to the point of disability, and causes heavy socioeconomic burdens to patients, their families, and society as a whole. The underlying pathogenic mechanisms of AD are complex and may involve excitotoxicity, excessive generation of reactive oxygen species (ROS), aberrant cell cycle reentry, impaired mitochondrial function, and DNA damage. Up to now, there is no effective treatment available for AD, and it is therefore urgent to develop an effective therapeutic regimen for this devastating disease. Sestrin2, belonging to the sestrin family, can counteract oxidative stress, reduce activity of the mammalian/mechanistic target of rapamycin (mTOR), and improve cell survival. It may therefore play a crucial role in neurodegenerative diseases like AD. However, only limited studies of sestrin2 and AD have been conducted up to now. In this article, we discuss current experimental evidence to demonstrate the potential roles of sestrin2 in treating neurodegenerative diseases, focusing specifically on AD. Strategies for augmenting sestrin2 expression may strengthen neurons, adapting them to stressful conditions through counteracting oxidative stress, and may also adjust the autophagy process, these two effects together conferring neuronal resistance in cases of AD.

Stellate Ganglion Block Successfully Treats Long COVID/PASC: A Case Series

The SARS-CoV-2 pandemic has resulted in a secondary pandemic of individuals suffering from pernicious symptoms termed “Long COVID” or PASC. In spite of significant societal impact, the condition remains mysterious and effective treatment remains elusive. Individuals experience debilitating symptoms including fatigue, “brain fog,” loss or altered smell and/or taste, anxiety and depression. Most of these symptoms are included in the “sickness behavior response” initiated from the brainstem when levels of circulating pro-inflammatory cytokines are high. Ordinarily a feedback loop prevents excessive production of these cytokines, however the SARS-CoV-2 virus has demonstrated the ability to induce the sympathetic nervous system (SNS), likely due to imbalance between ACE1 and ACE2 activity. Persistent sympathetic drive causes increased cytokine release, which interferes with the feedback loop that ends “sickness behaviors.” The stellate ganglion is a paravertebral collection of sympathetic nerves located in the cervical region that provides a convenient entry point to reduce activity of the SNS using local anesthetic blockade. The stellate ganglion block (SGB) has a well-established safety and efficacy profile for a variety of conditions involving the SNS. In this case report series, we treated three consecutive “Long COVID” patients with SGB. All three patients reported significant and durable improvement in symptoms including fatigue, “brain fog,” and smell and taste derangements. Our findings provide evidence implicating dysautonomia as the main etiology of Long COVID/PASC symptoms and suggest that SGB is an effective intervention for this condition with the potential to change the course of the second COVID pandemic, “Long COVID”/PASC.

Vestibulo-perceptual influences upon the vestibulo-spinal reflex

The vestibular system facilitates gaze and postural stability via the vestibulo-ocular (VOR) and vestibulo-spinal reflexes, respectively. Cortical and perceptual mechanisms can modulate long-duration VOR responses, but little is known about whether high-order neural phenomena can modulate short-latency vestibulo-spinal responses. Here, we investigate this by assessing click-evoked cervical vestibular myogenic-evoked potentials (VEMPS) during visual roll motion that elicited an illusionary sensation of self-motion (i.e. vection). We observed that during vection, the amplitude of the VEMPs was enhanced when compared to baseline measures. This modulation in VEMP amplitude was positively correlated with the subjective reports of vection strength. That is, those subjects reporting greater subjective vection scores exhibited a greater increase in VEMP amplitude. Control experiments showed that simple arousal (cold-induced discomfort) also increased VEMP amplitude but that, unlike vection, it did not modulate VEMP amplitude linearly. In agreement, small-field visual roll motion that did not induce vection failed to increase VEMP amplitude. Taken together, our results demonstrate that vection can modify the response of vestibulo-collic reflexes. Even short-latency brainstem vestibulo-spinal reflexes are influenced by high-order mechanisms, illustrating the functional importance of perceptual mechanisms in human postural control. As VEMPs are inhibitory responses, we argue that the findings may represent a mechanism whereby high-order CNS mechanisms reduce activity levels in vestibulo-collic reflexes, necessary for instance when voluntary head movements need to be performed.

Does the intrusion of an avian nest predator elicit a change in the behaviour of a canopy-nesting passerine?

Many studies have shown that nest predators affect their prey indirectly by inducing changes in the behaviour of the prey. Studies suggest that the type and degree of nest defence strategies depends heavily on species, along with nest type and location. One such strategy, nest vigilance, allows individuals to collect information and make informed decisions based on their surroundings. In this study, we simulated the intrusion of a common avian nest predator (blue jay, Cyanocitta cristata) into the territory of nesting cerulean warblers (Setophaga cerulea) and evaluated eight different behavioural variables to determine their response to the nest predator. Female cerulean warblers were more vigilant on their nest when exposed to a potential predator compared to a nest with lower threat of predation. Females exposed to a nest predator increased incubation bout by 109% and brooding bout by 60%. Our data also suggest that male cerulean warblers reduce their provisioning rate during the early nestling stage (−1 feeding/hour) and late nestling stage (−3 feedings/hour), although more data are needed. Modification of incubation bout length and nestling provisioning rate are common strategies employed by songbirds to reduce activity around the nest, by decreasing detection opportunities of visually-oriented nest predators. Currently, the only understanding we have on how cerulean warblers respond to a nest predator is based on observational data. The results of this study provide the first evidence that cerulean warblers are able to identify species that pose a threat to the safety of their nest, and that they modify their behaviour to reduce nest detection by predators. The results of this study provide a better understanding of a relatively unknown aspect of the breeding behaviour of this species. This study is also first to describe how an open-cup, canopy-nesting species responds to an increase in nest predation threat.

Dough flattening machine increase the performance of the onion chips artisan

Onion chips are foods made from a dough of flour, water and other ingredients that can be easily found in various places, but are generally made manually. Dough making is an activity that requires the longest time and greatly determines the quality of the resulting onion chips. Crafters need a long time, great effort and complaints of pain in several parts of the body due to this activity. This service activity provides a dough sheeting tool to facilitate the work of craftsmen and reduce activity time. The quality of the onion chips produced is getting better and craftsmen are also free from complaints of muscle pain.

Nicotinamide mononucleotide treatment increases NAD+ levels in an iPSC Model of Parkinson’s Disease but does not impact sirtuin activity

Objectives: Parkinson’s disease (PD) is a common neurodegenerative disorder caused by the loss of dopaminergic neurons in the substantia nigra. Although the underlying mechanisms of dopaminergic neuron loss is not fully understood, evidence suggests mitochondrial malfunction as a key contributor to disease pathogenesis. We previously found that human PD patient stem cell-derived dopaminergic neurons exhibit reduced nicotinamide adenine dinucleotide (NAD+) levels and reduce activity of sirtuins, a group of NAD+-dependent deacetylase enzymes that participate in the regulation of mitochondrial function, energy production, and cell survival. Thus, here we tested whether treatment of PD stem cell-derived dopaminergic neurons with nicotinamide mononucleotide (NMN), an NAD+ precursor, could increase NAD+ levels and improve sirtuin activity. Results: We treated PD iPSC-derived dopaminergic neurons with NMN and found that NAD+ levels did increase. The deacetylase activity of sirtuin (SIRT) 2 was improved with NMN treatment, but NMN had no impact on deacetylase activity of SIRT 1 or 3. These results suggest that NMN can restore NAD+ levels and SIRT 2 activity, but that additional mechanisms are involved SIRT 1 and 3 dysregulation in PD dopaminergic neurons.

Switching LPS to LED Streetlight May Dramatically Reduce Activity and Foraging of Bats

Artificial light at night is considered a major threat to biodiversity, especially for nocturnal species, as it reduces habitat availability, quality, and functionality. Since the recent evolution in light technologies in improving luminous efficacy, developed countries are experiencing a renewal of their lighting equipment that reaches its end-of-life, from conventional lighting technologies to light emitting diodes (LEDs). Despite potential cascading impacts of such a shift on nocturnal fauna, few studies have so far dealt with the impact of the renewal of street lighting by new technologies. Specifically, only one study, by Rowse et al.2016, examined the effects of switching from widely used low pressure sodium (LPS) lamps to LEDs, using bats as biological models. This study was based on a before-after-control-impact paired design (BACIP) at 12 pairs in the UK, each including one control and one experimental streetlight. If Rowse et al. 2016 showed no effect of switching to LEDs streetlights on bat activity, the effects of respective changes in light intensity and spectrum were not disentangled when testing switch effects. Here, we conduct a retrospective analysis of their data to include these covariates in statistical models with the aim of disentangling the relative effects of these light characteristics. Our re-analysis clearly indicates that the switches in spectrum and in intensity with replacement of LPS with LED lamps have significant additive and interactive effects, on bat activity. We also show that bat activity and buzz ratio decrease with increasing LED intensity while an opposite effect is observed with LPS lamps. Hence, the loss or the gain in bat activity when lamp types, i.e., spectrum, are switched strongly depends on the initial and new lamp intensities. Our results stress the need to consider simultaneously the effects of changes in the different lights characteristics when street lighting changes. Because switches from LPS to LED lamps can lead to an increase in light intensity, such technological changes may involve a reduction of bat activity in numerous cases, especially at high LED intensities. Since we are currently at an important crossroad in lighting management, we recommend to limit LED intensity and improve its spectral composition toward warmer colors to limit potential deleterious impacts on bat activity.