The Drosophila circadian clock gene cycle controls the development of clock neurons.

Daily behavioral and physiological rhythms are controlled by the brain's circadian timekeeping system, a synchronized network of neurons that maintains endogenous molecular oscillations. These oscillations are based on transcriptional feedback loops of clock genes, which in Drosophila include the transcriptional activators Clock (Clk) and cycle (cyc). While the mechanisms underlying this molecular clock are very well characterized, the roles that the core clock genes play in neuronal physiology and development are much less understood. The Drosophila timekeeping center is composed of ~150 clock neurons, among which the four small ventral lateral neurons (sLNvs) are the most dominant pacemakers under constant conditions. Here, we show that downregulating the clock gene cyc specifically in the Pdf-expressing neurons leads to decreased fasciculation both in larval and adult brains. This effect is due to a developmental role of cyc, as both knocking down cyc or expressing a dominant negative form of cyc exclusively during development lead to defasciculation phenotypes in adult clock neurons. Clk downregulation also leads to developmental effects on sLNv morphology. Our results reveal a non-circadian role for cyc, shedding light on the additional functions of circadian clock genes in the development of the nervous system.

Neurobiology and Changing Ecosystems: Mechanisms Underlying Responses to Human-Generated Environmental Impacts.

Human generated environmental change profoundly affects organisms that reside across diverse ecosystems. Although nervous systems evolved to flexibly sense, respond, and adapt to environmental change, it is unclear whether the rapid rate of environmental change outpaces the adaptive capacity of complex nervous systems. Here, we explore neural systems mediating responses to, or impacted by, changing environments, such as those induced by global heating, sensory pollution, and changing habitation zones. We focus on rising temperature and accelerated changes in environments that impact sensory experience as examples of perturbations that directly or indirectly impact neural function, respectively. We also explore a mechanism involved in cross-species interactions that arises from changing habitation zones. We demonstrate that anthropogenic influences on neurons, circuits, and behaviors are widespread across taxa and require further scientific investigation to understand principles underlying neural resilience to accelerating environmental change.SIGNIFICANCE STATEMENT Neural systems evolved over hundreds of millions of years to allow organisms to sense and respond to their environments - to be receptive and responsive, yet flexible. Recent rapid, human-generated environmental changes are testing the limits of the adaptive capacity of neural systems. This presents an opportunity and an urgency to understand how neurobiological processes, including molecular, cellular, and circuit-level mechanisms, are vulnerable or resilient to changing environmental conditions. We showcase examples that range from molecular to circuit to behavioral levels of analysis across several model species, framing a broad neuroscientific approach to explore topics of neural adaptation, plasticity, and resilience. We believe this emerging scientific area is of great societal and scientific importance and will provide a unique opportunity to reexamine our understanding of neural adaptation and the mechanisms underlying neural resilience.

The impact of the COVID-19 lockdown on retinopathy of prematurity screening and management in the United States: a multicenter study.

PURPOSE: To study the effect of the pandemic-related lockdown (physical distance measures and movement restrictions) on the characteristics and management of retinopathy of prematurity (ROP). METHODS: In this controlled, multicenter cohort study, the medical records of patients born prematurely and screened for ROP in the neonatal intensive care unit during four time periods were reviewed retrospectively: (1) November 1, 2018, to March 15, 2019; (2) March 16, 2019, to August 2, 2019 (lockdown control period); (3) November 1, 2019, to March 15, 2020; and (4) March 16, 2020-August 2, 2020. RESULTS: A total of 1,645 patients met inclusion criteria. Among the 1,633 patients with complete data, mean gestational age (GA) at birth was 28.2, 28.4, 28.0, and 28.3 weeks across time periods 1 to 4, respectively (P = 0.16). The mean birth weight of all patients was 1079.1 ± 378.60 g, with no significant variation across time periods (P = 0.08). There were fewer patients screened during the lockdown period (n = 411) compared with the period immediately before (n = 491) and the same period in the prior year (n = 533). Significantly more patients were screened using indirect ophthalmoscopy, compared to digital imaging (telemedicine), during the lockdown (P < 0.01). There were 11.7%, 7.7%, 9.0%, and 8.8% of patients requiring treatment in each time period, respectively (P = 0.42), with a median postmenstrual age at initial treatment of 37.2, 36.45, 37.1, and 36.3 weeks, respectively (P = 0.32). CONCLUSIONS: We recorded a decrease in the number of infants meeting criteria for ROP screening during the lockdown. The GA at birth and birth weight did not differ. Significantly more infants were screened with indirect ophthalmoscopy, compared to digital imaging, during the lockdown.

Comparing Methods for Quantifying and Analyzing Drosophila Aggression.

Here, we highlight three different assays that are used to study Drosophila aggression. The advantages and disadvantages of each assay are discussed, as examining different aspects of aggressive behavior presents distinct challenges to researchers. This is because aggression is not a singular behavioral unit. Rather, aggression is the result of interactions between individuals; and, as such, the initiation and frequency of these interactions are impacted by the assay parameters including the method of loading the flies into the observation chamber, the size of the chamber, and the animals' previous social experience. Thus, determining which assay to use depends on the overall question that is the subject of investigation.

Fighting Flies: Quantifying and Analyzing Drosophila Aggression.

Aggression is an innate behavior that likely evolved in the framework of defending or obtaining resources. This complex social behavior is influenced by genetic, environmental, and internal factors. Drosophila melanogaster remains an effective and exciting model organism with which to unravel the mechanistic basis of aggression due to its small but sophisticated brain, an impressive array of neurogenetic tools, and robust stereotypical behavioral patterns. The investigations of many laboratories have led to the identification of external and internal state factors that promote aggression, sex differences in the patterns and outcome of aggression, and neurotransmitters that regulate aggression.

Smith-Lemli-Optiz syndrome: importance of ophthalmology referral and follow-up.

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder caused by mutations in the 7-dehydrocholesterol reductase (DHCR7) gene, located on chromosomal region 11q13. This results in reduced cholesterol and increased 7-dehydrocholesterol (7DHC) levels. Accumulation of 7DHC in patients with SLOS can affect multiple organs and display a broad phenotypic expression. Ophthalmic abnormalities related to SLOS are variable but the most common is blepharoptosis. Over 50% of these patients present with self-injurious behavior, such as head banging, which can result in ocular complications and blindness. We report the first case of peripheral avascularity of the retina in a patient with SLOS. Physicians should be aware of the potential ocular complications associated with SLOS and confounding factors, such as prematurity, given that referral is usually delayed due to the lack of awareness of these potentially blinding associations. This case highlights the importance of early referral and continuous ophthalmologic follow-up in preventing further deterioration of visual development and complications that can lead to blindness.

Risk of tick-borne pathogen spillover into urban yards in New York City.

BACKGROUND: The incidence of tick-borne disease has increased dramatically in recent decades, with urban areas increasingly recognized as high-risk environments for exposure to infected ticks. Green spaces may play a key role in facilitating the invasion of ticks, hosts and pathogens into residential areas, particularly where they connect residential yards with larger natural areas (e.g. parks). However, the factors mediating tick distribution across heterogeneous urban landscapes remain poorly characterized. METHODS: Using generalized linear models in a multimodel inference framework, we determined the residential yard- and local landscape-level features associated with the presence of three tick species of current and growing public health importance in residential yards across Staten Island, a borough of New York City, in the state of New York, USA. RESULTS: The amount and configuration of canopy cover immediately surrounding residential yards was found to strongly predict the presence of Ixodes scapularis and Amblyomma americanum, but not that of Haemaphysalis longicornis. Within yards, we found a protective effect of fencing against I. scapularis and A. americanum, but not against H. longicornis. For all species, the presence of log and brush piles strongly increased the odds of finding ticks in yards. CONCLUSIONS: The results highlight a considerable risk of tick exposure in residential yards in Staten Island and identify both yard- and landscape-level features associated with their distribution. In particular, the significance of log and brush piles for all three species supports recommendations for yard management as a means of reducing contact with ticks.

Adaptation of the Multidimensional Body Self Relations Questionnaire for Young People Between 9 and 16 Years old.

BACKGROUND: Young adolescents and pre-adolescents are the population most vulnerable to disorders derived from a distorted Body Image (BI). In this study, the Multidimensional Body Self Relations Questionnaire, MBSR®, was adapted and validated for young Spanish people between 9 and 16 years old. METHOD: 719 young people of both sexes participated. The internal structure, the invariance of the measure according to sex and age, and evidence of validity and reliability of the measure were examined. RESULTS: the dimensional model found in adults was not replicated in young people. The simplest, best-fitting BI construct in young people, examined from the perspective of the BI construct contained in the MBSRQ®, consisted of 20 items in 4 differentially correlated factors. The internal consistency of the factors contained in the MBSRQ-SA-a was shown to be satisfactory, as was the evidence of concurrent validity. Factor invariance was demonstrated as a function of gender and three age groups. CONCLUSIONS: the MBSRQ-SA-a is reliable and valid for the study of BI in young people aged 9-16 years to the extent permitted by the content of the 4 factors making it up.

PHASE: An Open-Source Program for the Analysis of DrosophilaPhase, Activity, and Sleep Under Entrainment.

The problem of entrainment is central to circadian biology. In this regard, Drosophila has been an important model system. Owing to the simplicity of its nervous system and the availability of powerful genetic tools, the system has shed significant light on the molecular and neural underpinnings of entrainment. However, much remains to be learned regarding the molecular and physiological mechanisms underlying this important phenomenon. Under cyclic light/dark conditions, Drosophila melanogaster displays crepuscular patterns of locomotor activity with one peak anticipating dawn and the other anticipating dusk. These peaks are characterized through an estimation of their phase relative to the environmental light cycle and the extent of their anticipation of light transitions. In Drosophila chronobiology, estimations of phases are often subjective, and anticipation indices vary significantly between studies. Though there is increasing interest in building flexible analysis tools in the field, none incorporates objective measures of Drosophila activity peaks in combination with the analysis of fly activity/sleep in the same program. To this end, we have developed PHASE, a MATLAB-based program that is simple and easy to use and (i) supports the visualization and analysis of activity and sleep under entrainment, (ii) allows analysis of both activity and sleep parameters within user-defined windows within a diurnal cycle, (iii) uses a smoothing filter for the objective identification of peaks of activity (and therefore can be used to quantitatively characterize them), and (iv) offers a series of analyses for the assessment of behavioral anticipation of environmental transitions.

Coats plus in prematurity.

BACKGROUND: Coats plus syndrome or cerebroretinal microangiopathy with calcifications and cysts (CMCC) is an exceedingly rare autosomal recessive disorder that predominantly affects the microvasculature in the retina, brain, bones, and gastrointestinal system. Unlike Coats disease, CMCC is bilateral and affects multiple organ systems. MATERIALS AND METHODS: Case report. RESULTS: We report the case of two brothers with Coats Plus syndrome who presented with variable phenotypic expression. One sibling (Patient 1) was thought to have atypical retinopathy of prematurity and was only diagnosed with Coats plus after his older brother (Patient 2) presented with a seizure and a left upper extremity tremor at 4 years of age. The CTC1 mutation was confirmed in both patients. Aggressive treatment with laser photocoagulation and intravitreal bevacizumab dramatically improved the retinal vascular and exudative changes. CONCLUSION: Coats Plus syndrome can have a variable phenotypic presentation, including retinal vascular findings. This rare genetic disease should be in the differential diagnosis in patients who present with atypical retinal pathology, including Retinopathy of Prematurity, Familial Exudative Vitreoretinopathy, or Coats disease associated with non-specific multiorgan abnormalities.

Socio-ecological drivers of multiple zoonotic hazards in highly urbanized cities.

The ongoing COVID-19 pandemic is a stark reminder of the devastating consequences of pathogen spillover from wildlife to human hosts, particularly in densely populated urban centers. Prevention of future zoonotic disease is contingent on informed surveillance for known and novel threats across diverse human-wildlife interfaces. Cities are a key venue for potential spillover events because of the presence of zoonotic pathogens transmitted by hosts and vectors living in close proximity to dense human settlements. Effectively identifying and managing zoonotic hazards requires understanding the socio-ecological processes driving hazard distribution and pathogen prevalence in dynamic and heterogeneous urban landscapes. Despite increasing awareness of the human health impacts of zoonotic hazards, the integration of an eco-epidemiological perspective into public health management plans remains limited. Here we discuss how landscape patterns, abiotic conditions, and biotic interactions influence zoonotic hazards across highly urbanized cities (HUCs) in temperate climates to promote their efficient and effective management by a multi-sectoral coalition of public health stakeholders. We describe how to interpret both direct and indirect ecological processes, incorporate spatial scale, and evaluate networks of connectivity specific to different zoonotic hazards to promote biologically-informed and targeted decision-making. Using New York City, USA as a case study, we identify major zoonotic threats, apply knowledge of relevant ecological factors, and highlight opportunities and challenges for research and intervention. We aim to broaden the toolbox of urban public health stakeholders by providing ecologically-informed, practical guidance for the evaluation and management of zoonotic hazards.

Impact of Land Use Changes and Habitat Fragmentation on the Eco-epidemiology of Tick-Borne Diseases.

The incidence of tick-borne diseases has increased in recent decades and accounts for the majority of vector-borne disease cases in temperate areas of Europe, North America, and Asia. This emergence has been attributed to multiple and interactive drivers including changes in climate, land use, abundance of key hosts, and people's behaviors affecting the probability of human exposure to infected ticks. In this forum paper, we focus on how land use changes have shaped the eco-epidemiology of Ixodes scapularis-borne pathogens, in particular the Lyme disease spirochete Borrelia burgdorferi sensu stricto in the eastern United States. We use this as a model system, addressing other tick-borne disease systems as needed to illustrate patterns or processes. We first examine how land use interacts with abiotic conditions (microclimate) and biotic factors (e.g., host community composition) to influence the enzootic hazard, measured as the density of host-seeking I. scapularis nymphs infected with B. burgdorferi s.s. We then review the evidence of how specific landscape configuration, in particular forest fragmentation, influences the enzootic hazard and disease risk across spatial scales and urbanization levels. We emphasize the need for a dynamic understanding of landscapes based on tick and pathogen host movement and habitat use in relation to human resource provisioning. We propose a coupled natural-human systems framework for tick-borne diseases that accounts for the multiple interactions, nonlinearities and feedbacks in the system and conclude with a call for standardization of methodology and terminology to help integrate studies conducted at multiple scales.

Candidatus Frankia nodulisporulans sp. nov., an Alnus glutinosa-infective Frankia species unable to grow in pure culture and able to sporulate in-planta.

We describe a new Frankia species, for three non-isolated strains obtained from Alnus glutinosa in France and Sweden, respectively. These strains can nodulate several Alnus species (A. glutinosa, A. incana, A. alnobetula), they form hyphae, vesicles and sporangia in the root nodule cortex but have resisted all attempts at isolation in pure culture. Their genomes have been sequenced, they are significantly smaller than those of other Alnus-infective species (5Mb instead of 7.5Mb) and are very closely related to one another (ANI of 100%). The name Candidatus Frankia nodulisporulans is proposed. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene and draft genome sequences reported in this study for AgTrS, AgUmASt1 and AgUmASH1 are MT023539/LR778176/LR778180 and NZ_CADCWS000000000.1/CADDZU010000001/CADDZW010000001, respectively.

Proposal of 'Candidatus Frankia alpina', the uncultured symbiont of Alnus alnobetula and A. incana that forms spore-containing nitrogen-fixing root nodules.

The members of the genus Frankia are, with a few exceptions, a group of nitrogen-fixing symbiotic actinobacteria that nodulate mostly woody dicotyledonous plants belonging to three orders, eight families and 23 genera of pioneer dicots. These bacteria have been characterized phylogenetically and grouped into four molecular clusters. One of the clusters, cluster 1 contains strains that induce nodules on Alnus spp. (Betulaceae), Myrica spp., Morella spp. and Comptonia spp. (Myricaceae) that have global distributions. Some of these strains produce not only hyphae and vesicles, as other cluster 1 strains do, but also numerous sporangia in their host symbiotic tissues, hence their phenotype being described as spore-positive (Sp+). While Sp+ strains have resisted repeated attempts at cultivation, their genomes have recently been characterized and found to be different from those of all described species, being markedly smaller than their phylogenetic neighbours. We thus hereby propose to create a 'Candidatus Frankia alpina' species for some strains present in nodules of Alnus alnobetula and A. incana that grow in alpine environments at high altitudes or in subarctic environments at high latitudes.

Sites of Circadian Clock Neuron Plasticity Mediate Sensory Integration and Entrainment.

Networks of circadian timekeeping in the brain display marked daily changes in neuronal morphology. In Drosophila melanogaster, the striking daily structural remodeling of the dorsal medial termini of the small ventral lateral neurons has long been hypothesized to mediate endogenous circadian timekeeping. To test this model, we have specifically abrogated these sites of daily neuronal remodeling through the reprogramming of neural development and assessed the effects on circadian timekeeping and clock outputs. Remarkably, the loss of these sites has no measurable effects on endogenous circadian timekeeping or on any of the major output functions of the small ventral lateral neurons. Rather, their loss reduces sites of glutamatergic sensory neurotransmission that normally encodes naturalistic time cues from the environment. These results support an alternative model: structural plasticity in critical clock neurons is the basis for proper integration of light and temperature and gates sensory inputs into circadian clock neuron networks.

Current and Future Spatiotemporal Patterns of Lyme Disease Reporting in the Northeastern United States.

Importance: The incidence and geographic range of Lyme disease continues to increase in the United States because of the expansion of Ixodes scapularis, the species of tick that is the main Lyme disease vector. Currently, no dynamic model for the disease spread exists that integrates information of both acarological and human case surveillance data. Objective: To characterize the spatiotemporal spread of Lyme disease in humans among counties in US endemic regions. Design, Setting, and Participants: This cross-sectional study modeled the spread of Lyme disease county-level case reporting, accounting for county-level demographic factors, environmental factors associated with tick presence and human exposure, and the spatiotemporal association between counties. The analyses were conducted between January and August 2019. The setting was 1405 counties in the following regions of the United States: West North Central, East North Central, New England, Middle Atlantic, and the South. Assessments were based on publicly available Lyme disease case data reported to the US Centers for Disease Control and Prevention (CDC) between January 2000 and December 2017. Main Outcomes and Measures: Probability of reporting the first case of Lyme disease by county by year. Results: Between 2000 and 2017, a total of 497 569 Lyme disease cases were reported to the CDC in the study area. Reporting a first case of Lyme disease was associated with a county's and county's neighbors' forest coverage, elevation, percentage of population living in the wildland-urban interface, tick presence, county's population size, proportion of neighbors reporting cases, and neighbors' years since first reporting. The model that included these variables showed high predictive power, with a mean area under the receiver operating characteristic curve of 81.1 (95% CI, 68.5-86.2). The model predicted the first reported Lyme disease case a mean (SD) of 5.5 (3.5) years earlier than was reported to the CDC, with a mean spread velocity estimated at 27.4 (95% CI, 13.6-54.4) km per year. Among 162 counties without reported cases, 47 (29.0%) had a high probability of reporting Lyme disease by 2018. The estimated mean time lag between the first reported case in a neighboring county and any county was 7 (95% CI, 3-8) years. Conclusions and Relevance: This study's findings suggest that, if updated regularly and expanded geographically, this predictive model could enable states and counties to develop more specific Lyme disease prevention and control plans, including improved sensitization of the general population and medical community.

Red light delays programmed cell death in non-host interaction between Pseudomonas syringae pv tomato DC3000 and tobacco plants.

Light modulates almost every aspect of plant physiology, including plant-pathogen interactions. Among these, the hypersensitive response (HR) of plants to pathogens is characterized by a rapid and localized programmed cell death (PCD), which is critical to restrict the spread of pathogens from the infection site. The aim of this work was to study the role of light in the interaction between Pseudomonas syringae pv. tomato DC3000 (Pto DC3000) and non-host tobacco plants. To this end, we examined the HR under different light treatments (white and red light) by using a range of well-established markers of PCD. The alterations found at the cellular level included: i) loss of membrane integrity and nuclei, ii) RuBisCo and DNA degradation, and iii) changes in nuclease profiles and accumulation of cysteine proteinases. Our results suggest that red light plays a role during the HR of tobacco plants to Pto DC3000 infection, delaying the PCD process.

Human infectiousness and parasite load in chronic patients seropositive for Trypanosoma cruzi in a rural area of the Argentine Chaco.

A key parameter in the transmission of vector-borne infections, including Chagas disease, is the ability of the different host species to transmit the parasite to the vector (infectiousness). Here, we determined infectiousness to the vector of Trypanosoma cruzi-seropositive humans examined by artificial xenodiagnosis (XD), established its relationship with T. cruzi DNA levels (a surrogate of intensity of parasitemia) quantified by real-time PCR (qPCR), and assessed whether infectiousness was associated with the body mass index (BMI), age, ethnic background and parasite genotype. XD was performed to 117 T. cruzi-seropositive residents from Pampa del Indio and parasite load was quantified in 81 of them. Using optical microscopy (OM) 33.6% of the seropositive people tested were infectious and this fraction nearly doubled (66.0%) when XD triatomines were examined by kDNA-PCR. The mean infectiousness (defined as the percentage of all infected triatomines detected by OM at any time point among the total number of insects examined by OM 30 days post-feeding) was 5.2%, and the mean parasite load was 0.51 parasite equivalents per ml. Infectiousness to the vector was associated negatively with age and BMI, and positively with the detection of parasitemia by kDNA-PCR, and parasite load by qPCR in bivariate analysis. Patients with a positive XD by OM exhibited a significantly higher mean parasite load. Using multiple regression, infectiousness was associated with parasite load (positively) and with the household presence of T. infestans and Qom ethnic group (negatively); no significant association was observed with age or its interaction with ethnicity. We did not find significant associations between identified DTUs and infectiousness or parasite load. Infectiousness was aggregated: 18% of the people examined by XD generated 80% of the infected triatomines. Detecting and treating the super-infectious fraction of the infected human would disproportionally impact on domestic transmission risks. Nonetheless, treatment of all eligible infected people who meet the inclusion criteria regardless of their parasitemia should be ensured to improve their prognosis.

Solitary Fibrous Tumor of the Orbit: A Case Series With Clinicopathologic Correlation and Evaluation of STAT6 as a Diagnostic Marker.

PURPOSE: To retrospectively describe the clinical characteristics, management, and outcomes of a series of patients with solitary fibrous tumor (SFT) of the orbit and to evaluate signal transducer and activator of transcription 6 (STAT6) as a diagnostic marker. METHODS: Review of a retrospective, noncomparative, consecutive series of patients treated at a single institution with a histopathologic diagnosis of SFT. Demographic, clinical, and imaging data were collected, and paraffin-embedded tissue sections were stained to evaluate for the presence of STAT6 and other pertinent markers. RESULTS: Twenty-one patients were identified. Most presented with painless progressive proptosis or eyelid swelling for less than 6 months. Imaging revealed well-circumscribed, firm, variably vascular contrast-enhancing lesions with low to medium reflectivity on ultrasound. Four tumors were histopathologically malignant. All tumors were primarily excised, and 1 patient required exenteration. Two patients were treated with adjuvant radiation therapy. Six patients had recurrent disease of which 3 underwent repeat excision, and 2 were observed. No metastatic disease or attributable deaths were observed. All lesions with available tissue stained positively for both CD34 and STAT6. CONCLUSION: This is the largest single institution case series of orbital SFT with clinicopathologic correlation and the largest series to confirm the presence of STAT6 in orbital lesions. The management of SFT remains challenging due to unpredictable tumor behavior, and complete excision is the generally recommended treatment. It remains unclear whether a subset of asymptomatic patients with histopathologically benign disease can be durably observed without negative sequelae.